Commit Graph

4548 Commits

Author SHA1 Message Date
Joe Thornber
0184b44e32 dm cache policy mq: a few small fixes
Rename takeout_queue to concat_queue.

Fix a harmless bug in mq policies pop() function.  Currently pop()
always succeeds, with up coming changes this wont be the case.

Fix typo in comment above pre_cache_to_cache prototype.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:17 -05:00
Joe Thornber
3351937e4a dm cache policy: remove return from void policy_remove_mapping
No need to return from a void function.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:20:16 -05:00
Joe Thornber
238f8363b6 dm cache: improve efficiency of quiescing flag management
Make the quiescing flag an atomic_t and stop protecting it with a spin
lock.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 18:19:59 -05:00
Joe Thornber
66cb1910df dm cache: fix a race condition between queuing new migrations and quiescing for a shutdown
The code that was trying to do this was inadequate.  The postsuspend
method (in ioctl context), needs to wait for the worker thread to
acknowledge the request to quiesce.  Otherwise the migration count may
drop to zero temporarily before the worker thread realises we're
quiescing.  In this case the target will be taken down, but the worker
thread may have issued a new migration, which will cause an oops when
it completes.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
2013-11-09 17:55:50 -05:00
Joe Thornber
f8e5f01a32 dm cache: io destined for the cache device can now serve as tick bios
Previously only origin bios could trigger ticks, which meant if all
the io was destined for the cache no ticks were generated.  If no ticks
are generated then multiple hits, and movements in general, are
attributed to the same tick.

Only a stop gap fix, we need a better solution.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 17:55:49 -05:00
Joe Thornber
99ba2ae4cd dm cache policy mq: protect residency method with existing mutex
It is safe to use a mutex in mq_residency() at this point since it is
only called from ioctl context.  But future-proof mq_residency() by
using might_sleep() to catch new contexts that cannot sleep.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-09 17:54:34 -05:00
Kent Overstreet
6678d83f18 block: Consolidate duplicated bio_trim() implementations
Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on,
we should know better than this.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-08 09:02:31 -07:00
Linus Torvalds
0324e74534 Driver Core / sysfs patches for 3.13-rc1
Here's the big driver core / sysfs update for 3.13-rc1.
 
 There's lots of dev_groups updates for different subsystems, as they all
 get slowly migrated over to the safe versions of the attribute groups
 (removing userspace races with the creation of the sysfs files.)  Also
 in here are some kobject updates, devres expansions, and the first round
 of Tejun's sysfs reworking to enable it to be used by other subsystems
 as a backend for an in-kernel filesystem.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core / sysfs patches from Greg KH:
 "Here's the big driver core / sysfs update for 3.13-rc1.

  There's lots of dev_groups updates for different subsystems, as they
  all get slowly migrated over to the safe versions of the attribute
  groups (removing userspace races with the creation of the sysfs
  files.) Also in here are some kobject updates, devres expansions, and
  the first round of Tejun's sysfs reworking to enable it to be used by
  other subsystems as a backend for an in-kernel filesystem.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (83 commits)
  sysfs: rename sysfs_assoc_lock and explain what it's about
  sysfs: use generic_file_llseek() for sysfs_file_operations
  sysfs: return correct error code on unimplemented mmap()
  mdio_bus: convert bus code to use dev_groups
  device: Make dev_WARN/dev_WARN_ONCE print device as well as driver name
  sysfs: separate out dup filename warning into a separate function
  sysfs: move sysfs_hash_and_remove() to fs/sysfs/dir.c
  sysfs: remove unused sysfs_get_dentry() prototype
  sysfs: honor bin_attr.attr.ignore_lockdep
  sysfs: merge sysfs_elem_bin_attr into sysfs_elem_attr
  devres: restore zeroing behavior of devres_alloc()
  sysfs: fix sysfs_write_file for bin file
  input: gameport: convert bus code to use dev_groups
  input: serio: remove bus usage of dev_attrs
  input: serio: use DEVICE_ATTR_RO()
  i2o: convert bus code to use dev_groups
  memstick: convert bus code to use dev_groups
  tifm: convert bus code to use dev_groups
  virtio: convert bus code to use dev_groups
  ipack: convert bus code to use dev_groups
  ...
2013-11-07 11:42:15 +09:00
Joe Thornber
9c1d4de560 dm array: fix bug in growing array
Entries would be lost if the old tail block was partially filled.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.9+
2013-11-05 11:20:50 -05:00
Hannes Reinecke
b63349a7a5 dm mpath: requeue I/O during pg_init
When pg_init is running no I/O can be submitted to the underlying
devices, as the path priority etc might change.  When using queue_io for
this, requests will be piling up within multipath as the block I/O
scheduler just sees a _very fast_ device.  All of this queued I/O has to
be resubmitted from within multipathing once pg_init is done.

This approach has the problem that it's virtually impossible to
abort I/O when pg_init is running, and we're adding heavy load
to the devices after pg_init since all of the queued I/O needs to be
resubmitted _before_ any requests can be pulled off of the request queue
and normal operation continues.

This patch will requeue the I/O that triggers the pg_init call, and
return 'busy' when pg_init is in progress.  With these changes the block
I/O scheduler will stop submitting I/O during pg_init, resulting in a
quicker path switch and less I/O pressure (and memory consumption) after
pg_init.

Signed-off-by: Hannes Reinecke <hare@suse.de>
[patch header edited for clarity and typos by Mike Snitzer]
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-05 11:20:34 -05:00
Shiva Krishna Merla
954a73d5d3 dm mpath: fix race condition between multipath_dtr and pg_init_done
Whenever multipath_dtr() is happening we must prevent queueing any
further path activation work.  Implement this by adding a new
'pg_init_disabled' flag to the multipath structure that denotes future
path activation work should be skipped if it is set.  By disabling
pg_init and then re-enabling in flush_multipath_work() we also avoid the
potential for pg_init to be initiated while suspending an mpath device.

Without this patch a race condition exists that may result in a kernel
panic:

1) If after pg_init_done() decrements pg_init_in_progress to 0, a call
   to wait_for_pg_init_completion() assumes there are no more pending path
   management commands.
2) If pg_init_required is set by pg_init_done(), due to retryable
   mode_select errors, then process_queued_ios() will again queue the
   path activation work.
3) If free_multipath() completes before activate_path() work is called a
   NULL pointer dereference like the following can be seen when
   accessing members of the recently destructed multipath:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000090
RIP: 0010:[<ffffffffa003db1b>]  [<ffffffffa003db1b>] activate_path+0x1b/0x30 [dm_multipath]
[<ffffffff81090ac0>] worker_thread+0x170/0x2a0
[<ffffffff81096c80>] ? autoremove_wake_function+0x0/0x40

[switch to disabling pg_init in flush_multipath_work & header edits by Mike Snitzer]
Signed-off-by: Shiva Krishna Merla <shivakrishna.merla@netapp.com>
Reviewed-by: Krishnasamy Somasundaram <somasundaram.krishnasamy@netapp.com>
Tested-by: Speagle Andy <Andy.Speagle@netapp.com>
Acked-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2013-10-31 21:39:47 -04:00
Mikulas Patocka
f36afb3957 dm: allocate buffer for messages with small number of arguments using GFP_NOIO
dm-mpath and dm-thin must process messages even if some device is
suspended, so we allocate argv buffer with GFP_NOIO. These messages have
a small fixed number of arguments.

On the other hand, dm-switch needs to process bulk data using messages
so excessive use of GFP_NOIO could cause trouble.

The patch also lowers the default number of arguments from 64 to 8, so
that there is smaller load on GFP_NOIO allocations.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-10-31 13:55:45 -04:00
Shaohua Li
d47648fcf0 raid5: avoid finding "discard" stripe
SCSI discard will damage discard stripe bio setting, eg, some fields are
changed. If the stripe is reused very soon, we have wrong bios setting. We
remove discard stripe from hash list, so next time the strip will be fully
initialized.

Suitable for backport to 3.7+.

Cc: <stable@vger.kernel.org> (3.7+)
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-10-24 13:00:24 +11:00
Shaohua Li
37c61ff31e raid5: set bio bi_vcnt 0 for discard request
SCSI layer will add new payload for discard request. If two bios are merged
to one, the second bio has bi_vcnt 1 which is set in raid5. This will confuse
SCSI and cause oops.

Suitable for backport to 3.7+

Cc: stable@vger.kernel.org (v3.7+)
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
2013-10-24 12:57:36 +11:00
Bian Yu
905b0297a9 md: avoid deadlock when md_set_badblocks.
When operate harddisk and hit errors, md_set_badblocks is called after
scsi_restart_operations which already disabled the irq. but md_set_badblocks
will call write_sequnlock_irq and enable irq. so softirq can preempt the
current thread and that may cause a deadlock. I think this situation should
use write_sequnlock_irqsave/irqrestore instead.

I met the situation and the call trace is below:
[  638.919974] BUG: spinlock recursion on CPU#0, scsi_eh_13/1010
[  638.921923]  lock: 0xffff8800d4d51fc8, .magic: dead4ead, .owner: scsi_eh_13/1010, .owner_cpu: 0
[  638.923890] CPU: 0 PID: 1010 Comm: scsi_eh_13 Not tainted 3.12.0-rc5+ #37
[  638.925844] Hardware name: To be filled by O.E.M. To be filled by O.E.M./MAHOBAY, BIOS 4.6.5 03/05/2013
[  638.927816]  ffff880037ad4640 ffff880118c03d50 ffffffff8172ff85 0000000000000007
[  638.929829]  ffff8800d4d51fc8 ffff880118c03d70 ffffffff81730030 ffff8800d4d51fc8
[  638.931848]  ffffffff81a72eb0 ffff880118c03d90 ffffffff81730056 ffff8800d4d51fc8
[  638.933884] Call Trace:
[  638.935867]  <IRQ>  [<ffffffff8172ff85>] dump_stack+0x55/0x76
[  638.937878]  [<ffffffff81730030>] spin_dump+0x8a/0x8f
[  638.939861]  [<ffffffff81730056>] spin_bug+0x21/0x26
[  638.941836]  [<ffffffff81336de4>] do_raw_spin_lock+0xa4/0xc0
[  638.943801]  [<ffffffff8173f036>] _raw_spin_lock+0x66/0x80
[  638.945747]  [<ffffffff814a73ed>] ? scsi_device_unbusy+0x9d/0xd0
[  638.947672]  [<ffffffff8173fb1b>] ? _raw_spin_unlock+0x2b/0x50
[  638.949595]  [<ffffffff814a73ed>] scsi_device_unbusy+0x9d/0xd0
[  638.951504]  [<ffffffff8149ec47>] scsi_finish_command+0x37/0xe0
[  638.953388]  [<ffffffff814a75e8>] scsi_softirq_done+0xa8/0x140
[  638.955248]  [<ffffffff8130e32b>] blk_done_softirq+0x7b/0x90
[  638.957116]  [<ffffffff8104fddd>] __do_softirq+0xfd/0x330
[  638.958987]  [<ffffffff810b964f>] ? __lock_release+0x6f/0x100
[  638.960861]  [<ffffffff8174a5cc>] call_softirq+0x1c/0x30
[  638.962724]  [<ffffffff81004c7d>] do_softirq+0x8d/0xc0
[  638.964565]  [<ffffffff8105024e>] irq_exit+0x10e/0x150
[  638.966390]  [<ffffffff8174ad4a>] smp_apic_timer_interrupt+0x4a/0x60
[  638.968223]  [<ffffffff817499af>] apic_timer_interrupt+0x6f/0x80
[  638.970079]  <EOI>  [<ffffffff810b964f>] ? __lock_release+0x6f/0x100
[  638.971899]  [<ffffffff8173fa6a>] ? _raw_spin_unlock_irq+0x3a/0x50
[  638.973691]  [<ffffffff8173fa60>] ? _raw_spin_unlock_irq+0x30/0x50
[  638.975475]  [<ffffffff81562393>] md_set_badblocks+0x1f3/0x4a0
[  638.977243]  [<ffffffff81566e07>] rdev_set_badblocks+0x27/0x80
[  638.978988]  [<ffffffffa00d97bb>] raid5_end_read_request+0x36b/0x4e0 [raid456]
[  638.980723]  [<ffffffff811b5a1d>] bio_endio+0x1d/0x40
[  638.982463]  [<ffffffff81304ff3>] req_bio_endio.isra.65+0x83/0xa0
[  638.984214]  [<ffffffff81306b9f>] blk_update_request+0x7f/0x350
[  638.985967]  [<ffffffff81306ea1>] blk_update_bidi_request+0x31/0x90
[  638.987710]  [<ffffffff813085e0>] __blk_end_bidi_request+0x20/0x50
[  638.989439]  [<ffffffff8130862f>] __blk_end_request_all+0x1f/0x30
[  638.991149]  [<ffffffff81308746>] blk_peek_request+0x106/0x250
[  638.992861]  [<ffffffff814a62a9>] ? scsi_kill_request.isra.32+0xe9/0x130
[  638.994561]  [<ffffffff814a633a>] scsi_request_fn+0x4a/0x3d0
[  638.996251]  [<ffffffff813040a7>] __blk_run_queue+0x37/0x50
[  638.997900]  [<ffffffff813045af>] blk_run_queue+0x2f/0x50
[  638.999553]  [<ffffffff814a5750>] scsi_run_queue+0xe0/0x1c0
[  639.001185]  [<ffffffff814a7721>] scsi_run_host_queues+0x21/0x40
[  639.002798]  [<ffffffff814a2e87>] scsi_restart_operations+0x177/0x200
[  639.004391]  [<ffffffff814a4fe9>] scsi_error_handler+0xc9/0xe0
[  639.005996]  [<ffffffff814a4f20>] ? scsi_unjam_host+0xd0/0xd0
[  639.007600]  [<ffffffff81072f6b>] kthread+0xdb/0xe0
[  639.009205]  [<ffffffff81072e90>] ? flush_kthread_worker+0x170/0x170
[  639.010821]  [<ffffffff81748cac>] ret_from_fork+0x7c/0xb0
[  639.012437]  [<ffffffff81072e90>] ? flush_kthread_worker+0x170/0x170

This bug was introduce in commit  2e8ac30312
(the first time rdev_set_badblock was call from interrupt context),
so this patch is appropriate for 3.5 and subsequent kernels.

Cc: <stable@vger.kernel.org> (3.5+)
Signed-off-by: Bian Yu <bianyu@kedacom.com>
Reviewed-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-10-24 12:57:11 +11:00
Lukasz Dorau
61e4947c99 md: Fix skipping recovery for read-only arrays.
Since:
        commit 7ceb17e87b
        md: Allow devices to be re-added to a read-only array.

spares are activated on a read-only array. In case of raid1 and raid10
personalities it causes that not-in-sync devices are marked in-sync
without checking if recovery has been finished.

If a read-only array is degraded and one of its devices is not in-sync
(because the array has been only partially recovered) recovery will be skipped.

This patch adds checking if recovery has been finished before marking a device
in-sync for raid1 and raid10 personalities. In case of raid5 personality
such condition is already present (at raid5.c:6029).

Bug was introduced in 3.10 and causes data corruption.

Cc: stable@vger.kernel.org
Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-10-24 12:55:17 +11:00
Kent Overstreet
d4eddd42f5 bcache: Fixed incorrect order of arguments to bio_alloc_bioset()
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-23 07:55:36 +01:00
Greg Kroah-Hartman
a7204d72db Merge 3.12-rc6 into driver-core-next
We want these fixes here too.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-19 13:05:38 -07:00
Mikulas Patocka
e9c6a18264 dm snapshot: fix data corruption
This patch fixes a particular type of data corruption that has been
encountered when loading a snapshot's metadata from disk.

When we allocate a new chunk in persistent_prepare, we increment
ps->next_free and we make sure that it doesn't point to a metadata area
by further incrementing it if necessary.

When we load metadata from disk on device activation, ps->next_free is
positioned after the last used data chunk. However, if this last used
data chunk is followed by a metadata area, ps->next_free is positioned
erroneously to the metadata area. A newly-allocated chunk is placed at
the same location as the metadata area, resulting in data or metadata
corruption.

This patch changes the code so that ps->next_free skips the metadata
area when metadata are loaded in function read_exceptions.

The patch also moves a piece of code from persistent_prepare_exception
to a separate function skip_metadata to avoid code duplication.

CVE-2013-4299

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-10-16 03:17:47 +01:00
Michael Opdenacker
aa5e5dc2a8 treewide: fix "distingush" typo
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-10-14 15:38:33 +02:00
Kent Overstreet
2fe80d3bbf bcache: Fix a null ptr deref regression
Commit c0f04d88e4 ("bcache: Fix flushes in writeback mode") was fixing
a reported data corruption bug, but it seems some last minute
refactoring or rebasing introduced a null pointer deref.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Reported-by: Gabriel de Perthuis <g2p.code@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-10-10 18:17:39 -07:00
Greg Kroah-Hartman
88502b9c0a Merge 3.12-rc3 into driver-core-next
We want the driver core and sysfs fixes in here to make merges and
development easier.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-29 18:29:23 -07:00
Tejun Heo
388975ccca sysfs: clean up sysfs_get_dirent()
The pre-existing sysfs interfaces which take explicit namespace
argument are weird in that they place the optional @ns in front of
@name which is contrary to the established convention.  For example,
we end up forcing vast majority of sysfs_get_dirent() users to do
sysfs_get_dirent(parent, NULL, name), which is silly and error-prone
especially as @ns and @name may be interchanged without causing
compilation warning.

This renames sysfs_get_dirent() to sysfs_get_dirent_ns() and swap the
positions of @name and @ns, and sysfs_get_dirent() is now a wrapper
around sysfs_get_dirent_ns().  This makes confusions a lot less
likely.

There are other interfaces which take @ns before @name.  They'll be
updated by following patches.

This patch doesn't introduce any functional changes.

v2: EXPORT_SYMBOL_GPL() wasn't updated leading to undefined symbol
    error on module builds.  Reported by build test robot.  Fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26 15:33:18 -07:00
Linus Torvalds
e93dd910b9 A set of device-mapper fixes for 3.12.
A few fixes for dm-snapshot, a 32 bit fix for dm-stats, a couple error
 handling fixes for dm-multipath.  A fix for the thin provisioning target
 to not expose non-zero discard limits if discards are disabled.
 
 Lastly, add two DM module parameters which allow users to tune the
 emergency memory reserves that DM mainatins per device -- this helps fix
 a long-standing issue for dm-multipath.  The conservative default
 reserve for request-based dm-multipath devices (256) has proven
 problematic for users with many multipathed SCSI devices but relatively
 little memory.  To responsibly select a smaller value users should use
 the new nr_bios tracepoint info (via commit 75afb352 "block: Add nr_bios
 to block_rq_remap tracepoint") to determine the peak number of bios
 their workloads create.
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Merge tag 'dm-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device-mapper fixes from Mike Snitzer:
 "A few fixes for dm-snapshot, a 32 bit fix for dm-stats, a couple error
  handling fixes for dm-multipath.  A fix for the thin provisioning
  target to not expose non-zero discard limits if discards are disabled.

  Lastly, add two DM module parameters which allow users to tune the
  emergency memory reserves that DM mainatins per device -- this helps
  fix a long-standing issue for dm-multipath.  The conservative default
  reserve for request-based dm-multipath devices (256) has proven
  problematic for users with many multipathed SCSI devices but
  relatively little memory.  To responsibly select a smaller value users
  should use the new nr_bios tracepoint info (via commit 75afb352
  "block: Add nr_bios to block_rq_remap tracepoint") to determine the
  peak number of bios their workloads create"

* tag 'dm-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: add reserved_bio_based_ios module parameter
  dm: add reserved_rq_based_ios module parameter
  dm: lower bio-based mempool reservation
  dm thin: do not expose non-zero discard limits if discards disabled
  dm mpath: disable WRITE SAME if it fails
  dm-snapshot: fix performance degradation due to small hash size
  dm snapshot: workaround for a false positive lockdep warning
  dm stats: fix possible counter corruption on 32-bit systems
  dm mpath: do not fail path on -ENOSPC
2013-09-25 15:12:46 -07:00
Kent Overstreet
c0f04d88e4 bcache: Fix flushes in writeback mode
In writeback mode, when we get a cache flush we need to make sure we
issue a flush to the backing device.

The code for sending down an extra flush was wrong - by cloning the bio
we were probably getting flags that didn't make sense for a bare flush,
and also the old code was firing for FUA bios, for which we don't need
to send a flush to the backing device.

This was causing data corruption somehow - the mechanism was never
determined, but this patch fixes it for the users that were seeing it.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet
84786438ed bcache: Fix for handling overlapping extents when reading in a btree node
btree_sort_fixup() was overly clever, because it was trying to avoid
pulling a key off the btree iterator in more than one place.

This led to a really obscure bug where we'd break early from the loop in
btree_sort_fixup() if the current key overlapped with keys in more than
one older set, and the next key it overlapped with was zero size.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet
a698e08c82 bcache: Fix a shrinker deadlock
GFP_NOIO means we could be getting called recursively - mca_alloc() ->
mca_data_alloc() - definitely can't use mutex_lock(bucket_lock) then.
Whoops.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet
79e3dab90d bcache: Fix a dumb CPU spinning bug in writeback
schedule_timeout() != schedule_timeout_uninterruptible()

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet
1394d6761b bcache: Fix a flush/fua performance bug
bch_journal_meta() was missing the flush to make the journal write
actually go down (instead of waiting up to journal_delay_ms)...

Whoops

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet
c2a4f3183a bcache: Fix a writeback performance regression
Background writeback works by scanning the btree for dirty data and
adding those keys into a fixed size buffer, then for each dirty key in
the keybuf writing it to the backing device.

When read_dirty() finishes and it's time to scan for more dirty data, we
need to wait for the outstanding writeback IO to finish - they still
take up slots in the keybuf (so that foreground writes can check for
them to avoid races) - without that wait, we'll continually rescan when
we'll be able to add at most a key or two to the keybuf, and that takes
locks that starves foreground IO.  Doh.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Geert Uytterhoeven
61cbd250f8 bcache: Correct printf()-style format length modifier
Fix

  drivers/md/bcache/btree.c: In function ‘bch_btree_node_read’:
  drivers/md/bcache/btree.c:259: warning: format ‘%lu’ expects type ‘long unsigned int’, but argument 3 has type ‘size_t’

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet
c426c4fd46 bcache: Fix for when no journal entries are found
The journal replay code didn't handle this case, causing it to go into
an infinite loop...

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Gabriel de Perthuis
aee6f1cfff bcache: Strip endline when writing the label through sysfs
sysfs attributes with unusual characters have crappy failure modes
in Squeeze (udev 164); later versions of udev are unaffected.

This should make these characters more unusual.

Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Kent Overstreet
6d9d21e35f bcache: Fix a dumb journal discard bug
That switch statement was obviously wrong, leading to some sort of weird
spinning on rare occasion with discards enabled...

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24 14:41:43 -07:00
Mike Snitzer
e8603136cb dm: add reserved_bio_based_ios module parameter
Allow user to change the number of IOs that are reserved by
bio-based DM's mempools by writing to this file:
/sys/module/dm_mod/parameters/reserved_bio_based_ios

The default value is RESERVED_BIO_BASED_IOS (16).  The maximum allowed
value is RESERVED_MAX_IOS (1024).

Export dm_get_reserved_bio_based_ios() for use by DM targets and core
code.  Switch to sizing dm-io's mempool and bioset using DM core's
configurable 'reserved_bio_based_ios'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Frank Mayhar <fmayhar@google.com>
2013-09-23 10:42:24 -04:00
Mike Snitzer
f47908269f dm: add reserved_rq_based_ios module parameter
Allow user to change the number of IOs that are reserved by
request-based DM's mempools by writing to this file:
/sys/module/dm_mod/parameters/reserved_rq_based_ios

The default value is RESERVED_REQUEST_BASED_IOS (256).  The maximum
allowed value is RESERVED_MAX_IOS (1024).

Export dm_get_reserved_rq_based_ios() for use by DM targets and core
code.  Switch to sizing dm-mpath's mempool using DM core's configurable
'reserved_rq_based_ios'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Frank Mayhar <fmayhar@google.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
2013-09-23 10:42:24 -04:00
Mike Snitzer
6cfa58573f dm: lower bio-based mempool reservation
Bio-based device mapper processing doesn't need larger mempools (like
request-based DM does), so lower the number of reserved entries for
bio-based operation.  16 was already used for bio-based DM's bioset
but mistakenly wasn't used for it's _io_cache.

Formalize difference between bio-based and request-based defaults by
introducing RESERVED_BIO_BASED_IOS and RESERVED_REQUEST_BASED_IOS.

(based on older code from Mikulas Patocka)

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Frank Mayhar <fmayhar@google.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
2013-09-23 10:42:23 -04:00
Mike Snitzer
b60ab990cc dm thin: do not expose non-zero discard limits if discards disabled
Fix issue where the block layer would stack the discard limits of the
pool's data device even if the "ignore_discard" pool feature was
specified.

The pool and thin device(s) still had discards disabled because the
QUEUE_FLAG_DISCARD request_queue flag wasn't set.  But to avoid user
confusion when "ignore_discard" is used: both the pool device and the
thin device(s) have zeroes for all discard limits.

Also, always set discard_zeroes_data_unsupported in targets because they
should never advertise the 'discard_zeroes_data' capability (even if the
pool's data device supports it).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-09-23 10:42:06 -04:00
Mike Snitzer
f84cb8a46a dm mpath: disable WRITE SAME if it fails
Workaround the SCSI layer's problematic WRITE SAME heuristics by
disabling WRITE SAME in the DM multipath device's queue_limits if an
underlying device disabled it.

The WRITE SAME heuristics, with both the original commit 5db44863b6
("[SCSI] sd: Implement support for WRITE SAME") and the updated commit
66c28f971 ("[SCSI] sd: Update WRITE SAME heuristics"), default to enabling
WRITE SAME(10) even without successfully determining it is supported.
After the first failed WRITE SAME the SCSI layer will disable WRITE SAME
for the device (by setting sdkp->device->no_write_same which results in
'max_write_same_sectors' in device's queue_limits to be set to 0).

When a device is stacked ontop of such a SCSI device any changes to that
SCSI device's queue_limits do not automatically propagate up the stack.
As such, a DM multipath device will not have its WRITE SAME support
disabled.  This causes the block layer to continue to issue WRITE SAME
requests to the mpath device which causes paths to fail and (if mpath IO
isn't configured to queue when no paths are available) it will result in
actual IO errors to the upper layers.

This fix doesn't help configurations that have additional devices
stacked ontop of the mpath device (e.g. LVM created linear DM devices
ontop).  A proper fix that restacks all the queue_limits from the bottom
of the device stack up will need to be explored if SCSI will continue to
use this model of optimistically allowing op codes and then disabling
them after they fail for the first time.

Before this patch:

EXT4-fs (dm-6): mounted filesystem with ordered data mode. Opts: (null)
device-mapper: multipath: XXX snitm debugging: got -EREMOTEIO (-121)
device-mapper: multipath: XXX snitm debugging: failing WRITE SAME IO with error=-121
end_request: critical target error, dev dm-6, sector 528
dm-6: WRITE SAME failed. Manually zeroing.
device-mapper: multipath: Failing path 8:112.
end_request: I/O error, dev dm-6, sector 4616
dm-6: WRITE SAME failed. Manually zeroing.
end_request: I/O error, dev dm-6, sector 4616
end_request: I/O error, dev dm-6, sector 5640
end_request: I/O error, dev dm-6, sector 6664
end_request: I/O error, dev dm-6, sector 7688
end_request: I/O error, dev dm-6, sector 524288
Buffer I/O error on device dm-6, logical block 65536
lost page write due to I/O error on dm-6
JBD2: Error -5 detected when updating journal superblock for dm-6-8.
end_request: I/O error, dev dm-6, sector 524296
Aborting journal on device dm-6-8.
end_request: I/O error, dev dm-6, sector 524288
Buffer I/O error on device dm-6, logical block 65536
lost page write due to I/O error on dm-6
JBD2: Error -5 detected when updating journal superblock for dm-6-8.

# cat /sys/block/sdh/queue/write_same_max_bytes
0
# cat /sys/block/dm-6/queue/write_same_max_bytes
33553920

After this patch:

EXT4-fs (dm-6): mounted filesystem with ordered data mode. Opts: (null)
device-mapper: multipath: XXX snitm debugging: got -EREMOTEIO (-121)
device-mapper: multipath: XXX snitm debugging: WRITE SAME I/O failed with error=-121
end_request: critical target error, dev dm-6, sector 528
dm-6: WRITE SAME failed. Manually zeroing.

# cat /sys/block/sdh/queue/write_same_max_bytes
0
# cat /sys/block/dm-6/queue/write_same_max_bytes
0

It should be noted that WRITE SAME support wasn't enabled in DM
multipath until v3.10.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org # 3.10+
2013-09-20 10:36:34 -04:00
Mikulas Patocka
60e356f381 dm-snapshot: fix performance degradation due to small hash size
LVM2, since version 2.02.96, creates origin with zero size, then loads
the snapshot driver and then loads the origin.  Consequently, the
snapshot driver sees the origin size zero and sets the hash size to the
lower bound 64.  Such small hash table causes performance degradation.

This patch changes it so that the hash size is determined by the size of
snapshot volume, not minimum of origin and snapshot size.  It doesn't
make sense to set the snapshot size significantly larger than the origin
size, so we do not need to take origin size into account when
calculating the hash size.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2013-09-20 10:36:34 -04:00
Mikulas Patocka
5ea330a75b dm snapshot: workaround for a false positive lockdep warning
The kernel reports a lockdep warning if a snapshot is invalidated because
it runs out of space.

The lockdep warning was triggered by commit 0976dfc1d0
("workqueue: Catch more locking problems with flush_work()") in v3.5.

The warning is false positive.  The real cause for the warning is that
the lockdep engine treats different instances of md->lock as a single
lock.

This patch is a workaround - we use flush_workqueue instead of flush_work.
This code path is not performance sensitive (it is called only on
initialization or invalidation), thus it doesn't matter that we flush the
whole workqueue.

The real fix for the problem would be to teach the lockdep engine to treat
different instances of md->lock as separate locks.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.5+
2013-09-20 10:36:34 -04:00
Mikulas Patocka
bbf3f8cbdc dm stats: fix possible counter corruption on 32-bit systems
There was a deliberate race condition in dm_stat_for_entry() to avoid the
overhead of disabling and enabling interrupts.  The race could result in
some events not being counted on 64-bit architectures.

However, on 32-bit architectures, operations on long long variables are
not atomic, so the race condition could cause the counter to jump by 2^32.
Such jumps could be disruptive, so we need to do proper locking on 32-bit
architectures.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Alasdair G. Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-09-18 14:41:06 -04:00
Jun'ichi Nomura
cc9d3c382b dm mpath: do not fail path on -ENOSPC
Since ENOSPC is a target-side error, dm-mpath should just pass the error
information to upper layer instead of retrying itself with path failover.
Otherwise it will end up failing all paths down while path checkers find
all paths ok.

ENOSPC can now be returned from SCSI device after commit a9d6ceb8
("[SCSI] return ENOSPC on thin provisioning failure").

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-09-18 14:41:06 -04:00
Linus Torvalds
26935fb06e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile 4 from Al Viro:
 "list_lru pile, mostly"

This came out of Andrew's pile, Al ended up doing the merge work so that
Andrew didn't have to.

Additionally, a few fixes.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (42 commits)
  super: fix for destroy lrus
  list_lru: dynamically adjust node arrays
  shrinker: Kill old ->shrink API.
  shrinker: convert remaining shrinkers to count/scan API
  staging/lustre/libcfs: cleanup linux-mem.h
  staging/lustre/ptlrpc: convert to new shrinker API
  staging/lustre/obdclass: convert lu_object shrinker to count/scan API
  staging/lustre/ldlm: convert to shrinkers to count/scan API
  hugepage: convert huge zero page shrinker to new shrinker API
  i915: bail out earlier when shrinker cannot acquire mutex
  drivers: convert shrinkers to new count/scan API
  fs: convert fs shrinkers to new scan/count API
  xfs: fix dquot isolation hang
  xfs-convert-dquot-cache-lru-to-list_lru-fix
  xfs: convert dquot cache lru to list_lru
  xfs: rework buffer dispose list tracking
  xfs-convert-buftarg-lru-to-generic-code-fix
  xfs: convert buftarg LRU to generic code
  fs: convert inode and dentry shrinking to be node aware
  vmscan: per-node deferred work
  ...
2013-09-12 15:01:38 -07:00
Dave Chinner
7dc19d5aff drivers: convert shrinkers to new count/scan API
Convert the driver shrinkers to the new API.  Most changes are compile
tested only because I either don't have the hardware or it's staging
stuff.

FWIW, the md and android code is pretty good, but the rest of it makes me
want to claw my eyes out.  The amount of broken code I just encountered is
mind boggling.  I've added comments explaining what is broken, but I fear
that some of the code would be best dealt with by being dragged behind the
bike shed, burying in mud up to it's neck and then run over repeatedly
with a blunt lawn mower.

Special mention goes to the zcache/zcache2 drivers.  They can't co-exist
in the build at the same time, they are under different menu options in
menuconfig, they only show up when you've got the right set of mm
subsystem options configured and so even compile testing is an exercise in
pulling teeth.  And that doesn't even take into account the horrible,
broken code...

[glommer@openvz.org: fixes for i915, android lowmem, zcache, bcache]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:32 -04:00
Linus Torvalds
7426d62871 Add the ability to collect I/O statistics on user-defined regions of a
device-mapper device.  This dm-stats code required the reintroduction of
 a div64_u64_rem() helper, but as a separate method that doesn't slow
 down div64_u64() -- especially on 32-bit systems.
 
 Allow the error target to replace request-based DM devices
 (e.g. multipath) in addition to bio-based DM devices.
 
 Various other small code fixes and improvements to thin-provisioning, DM
 cache and the DM ioctl interface.
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Merge tag 'dm-3.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device-mapper updates from Mike Snitzer:
 "Add the ability to collect I/O statistics on user-defined regions of a
  device-mapper device.  This dm-stats code required the reintroduction
  of a div64_u64_rem() helper, but as a separate method that doesn't
  slow down div64_u64() -- especially on 32-bit systems.

  Allow the error target to replace request-based DM devices (e.g.
  multipath) in addition to bio-based DM devices.

  Various other small code fixes and improvements to thin-provisioning,
  DM cache and the DM ioctl interface"

* tag 'dm-3.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm stripe: silence a couple sparse warnings
  dm: add statistics support
  dm thin: always return -ENOSPC if no_free_space is set
  dm ioctl: cleanup error handling in table_load
  dm ioctl: increase granularity of type_lock when loading table
  dm ioctl: prevent rename to empty name or uuid
  dm thin: set pool read-only if breaking_sharing fails block allocation
  dm thin: prefix pool error messages with pool device name
  dm: allow error target to replace bio-based and request-based targets
  math64: New separate div64_u64_rem helper
  dm space map: optimise sm_ll_dec and sm_ll_inc
  dm btree: prefetch child nodes when walking tree for a dm_btree_del
  dm btree: use pop_frame in dm_btree_del to cleanup code
  dm cache: eliminate holes in cache structure
  dm cache: fix stacking of geometry limits
  dm thin: fix stacking of geometry limits
  dm thin: add data block size limits to Documentation
  dm cache: add data block size limits to code and Documentation
  dm cache: document metadata device is exclussive to a cache
  dm: stop using WQ_NON_REENTRANT
2013-09-10 13:06:15 -07:00
Linus Torvalds
4d7696f1b0 md update for v3.12
Headline item is multithreading for RAID5 so that more
 IO/sec can be supported on fast (SSD) devices.
 Also TILE-Gx SIMD suppor for RAID6 calculations and an
 assortment of bug fixes.
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Merge tag 'md/3.12' of git://neil.brown.name/md

Pull md update from Neil Brown:
 "Headline item is multithreading for RAID5 so that more IO/sec can be
  supported on fast (SSD) devices.  Also TILE-Gx SIMD suppor for RAID6
  calculations and an assortment of bug fixes"

* tag 'md/3.12' of git://neil.brown.name/md:
  raid5: only wakeup necessary threads
  md/raid5: flush out all pending requests before proceeding with reshape.
  md/raid5: use seqcount to protect access to shape in make_request.
  raid5: sysfs entry to control worker thread number
  raid5: offload stripe handle to workqueue
  raid5: fix stripe release order
  raid5: make release_stripe lockless
  md: avoid deadlock when dirty buffers during md_stop.
  md: Don't test all of mddev->flags at once.
  md: Fix apparent cut-and-paste error in super_90_validate
  raid6/test: replace echo -e with printf
  RAID: add tilegx SIMD implementation of raid6
  md: fix safe_mode buglet.
  md: don't call md_allow_write in get_bitmap_file.
2013-09-10 13:03:41 -07:00
Mike Snitzer
7fff5e8f72 dm stripe: silence a couple sparse warnings
Eliminate the following sparse warnings:
drivers/md/dm-stripe.c:443:12: warning: symbol 'dm_stripe_init' was not declared. Should it be static?
drivers/md/dm-stripe.c:456:6: warning: symbol 'dm_stripe_exit' was not declared. Should it be static?

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-06 11:36:01 -04:00
Mikulas Patocka
fd2ed4d252 dm: add statistics support
Support the collection of I/O statistics on user-defined regions of
a DM device.  If no regions are defined no statistics are collected so
there isn't any performance impact.  Only bio-based DM devices are
currently supported.

Each user-defined region specifies a starting sector, length and step.
Individual statistics will be collected for each step-sized area within
the range specified.

The I/O statistics counters for each step-sized area of a region are
in the same format as /sys/block/*/stat or /proc/diskstats but extra
counters (12 and 13) are provided: total time spent reading and
writing in milliseconds.  All these counters may be accessed by sending
the @stats_print message to the appropriate DM device via dmsetup.

The creation of DM statistics will allocate memory via kmalloc or
fallback to using vmalloc space.  At most, 1/4 of the overall system
memory may be allocated by DM statistics.  The admin can see how much
memory is used by reading
/sys/module/dm_mod/parameters/stats_current_allocated_bytes

See Documentation/device-mapper/statistics.txt for more details.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer
94563badaf dm thin: always return -ENOSPC if no_free_space is set
If pool has 'no_free_space' set it means a previous allocation already
determined the pool has no free space (and failed that allocation with
-ENOSPC).  By always returning -ENOSPC if 'no_free_space' is set, we do
not allow the pool to oscillate between allocating blocks and then not.

But a side-effect of this determinism is that if a user wants to be able
to allocate new blocks they'll need to reload the pool's table (to clear
the 'no_free_space' flag).  This reload will happen automatically if the
pool's data volume is resized.  But if the user takes action to free a
lot of space by deleting snapshot volumes, etc the pool will no longer
allow data allocations to continue without an intervening table reload.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer
f11c1c5693 dm ioctl: cleanup error handling in table_load
Make use of common cleanup code.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer
00c4fc3b1f dm ioctl: increase granularity of type_lock when loading table
Hold the mapped device's type_lock before calling populate_table() since
it is where the table's type is determined based on the specified
targets.  There is no need to allow concurrent table loads to race to
establish the table's targets or type.

This eliminates the need to grab the lock in dm_table_set_type().

Also verify that the type_lock is held in both dm_set_md_type() and
dm_get_md_type().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Alasdair Kergon
c2b0482462 dm ioctl: prevent rename to empty name or uuid
A device-mapper device must always have a name consisting of a non-empty
string.  If the device also has a uuid, this similarly must not be an
empty string.

The DM_DEV_CREATE ioctl enforces these rules when the device is created,
but this patch is needed to enforce them when DM_DEV_RENAME is used to
change the name or uuid.

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer
d6fc204201 dm thin: set pool read-only if breaking_sharing fails block allocation
break_sharing() now handles an arbitrary alloc_data_block() error
the same way as provision_block(): marks pool read-only and errors the
cell.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:06 -04:00
Mike Snitzer
4fa5971a69 dm thin: prefix pool error messages with pool device name
Useful to know which pool is experiencing the error.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:05 -04:00
Mike Snitzer
169e2cc279 dm: allow error target to replace bio-based and request-based targets
It may be useful to switch a request-based table to the "error" target.
Enhance the DM core to allow a hybrid target_type which is capable of
handling either bios (via .map) or requests (via .map_rq).

Add a request-based map function (.map_rq) to the "error" target_type;
making it DM's first hybrid target.  Train dm_table_set_type() to prefer
the mapped device's established type (request-based or bio-based).  If
the mapped device doesn't have an established type default to making the
table with the hybrid target(s) bio-based.

Tested 'dmsetup wipe_table' to work on both bio-based and request-based
devices.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-09-05 20:46:05 -04:00
Linus Torvalds
f66c83d059 SCSI misc on 20130903
This patch set is a set of driver updates (ufs, zfcp, lpfc, mpt2/3sas,
 qla4xxx, qla2xxx [adding support for ISP8044 + other things]) we also have a
 new driver: esas2r which has a number of static checker problems, but which I
 expect to resolve over the -rc course of 3.12 under the new driver exception.
 We also have the error return updates that were discussed at LSF.
 
 Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull first round of SCSI updates from James Bottomley:
 "This patch set is a set of driver updates (ufs, zfcp, lpfc, mpt2/3sas,
  qla4xxx, qla2xxx [adding support for ISP8044 + other things]).

  We also have a new driver: esas2r which has a number of static checker
  problems, but which I expect to resolve over the -rc course of 3.12
  under the new driver exception.

  We also have the error return that were discussed at LSF"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (118 commits)
  [SCSI] sg: push file descriptor list locking down to per-device locking
  [SCSI] sg: checking sdp->detached isn't protected when open
  [SCSI] sg: no need sg_open_exclusive_lock
  [SCSI] sg: use rwsem to solve race during exclusive open
  [SCSI] scsi_debug: fix logical block provisioning support when unmap_alignment != 0
  [SCSI] scsi_debug: fix endianness bug in sdebug_build_parts()
  [SCSI] qla2xxx: Update the driver version to 8.06.00.08-k.
  [SCSI] qla2xxx: print MAC via %pMR.
  [SCSI] qla2xxx: Correction to message ids.
  [SCSI] qla2xxx: Correctly print out/in mailbox registers.
  [SCSI] qla2xxx: Add a new interface to update versions.
  [SCSI] qla2xxx: Move queue depth ramp down message to i/o debug level.
  [SCSI] qla2xxx: Select link initialization option bits from current operating mode.
  [SCSI] qla2xxx: Add loopback IDC-TIME-EXTEND aen handling support.
  [SCSI] qla2xxx: Set default critical temperature value in cases when ISPFX00 firmware doesn't provide it
  [SCSI] qla2xxx: QLAFX00 make over temperature AEN handling informational, add log for normal temperature AEN
  [SCSI] qla2xxx: Correct Interrupt Register offset for ISPFX00
  [SCSI] qla2xxx: Remove handling of Shutdown Requested AEN from qlafx00_process_aen().
  [SCSI] qla2xxx: Send all AENs for ISPFx00 to above layers.
  [SCSI] qla2xxx: Add changes in initialization for ISPFX00 cards with BIOS
  ...
2013-09-03 15:48:06 -07:00
Shaohua Li
bfc90cb093 raid5: only wakeup necessary threads
If there are not enough stripes to handle, we'd better not always
queue all available work_structs. If one worker can only handle small
or even none stripes, it will impact request merge and create lock
contention.

With this patch, the number of work_struct running will depend on
pending stripes number. Note: some statistics info used in the patch
are accessed without locking protection. This should doesn't matter,
we just try best to avoid queue unnecessary work_struct.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-09-02 10:31:29 +10:00
NeilBrown
4d77e3ba88 md/raid5: flush out all pending requests before proceeding with reshape.
Some requests - particularly 'discard' and 'read' are handled
differently depending on whether a reshape is active or not.

It is harmless to assume reshape is active if it isn't but wrong
to act as though reshape is not active when it is.

So when we start reshape - after making clear to all requests that
reshape has started - use mddev_suspend/mddev_resume to flush out all
requests.  This will ensure that no requests will be assuming the
absence of reshape once it really starts.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 16:58:44 +10:00
NeilBrown
c46501b2de md/raid5: use seqcount to protect access to shape in make_request.
make_request() access various shape parameters (raid_disks, chunk_size
etc) which might be changed by raid5_start_reshape().

If the later is called at and awkward time during the form, the wrong
stripe_head might be used.

So introduce a 'seqcount' and after finding a stripe_head make sure
there is no reason to expect that we got the wrong one.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 16:58:36 +10:00
Shaohua Li
b721420e87 raid5: sysfs entry to control worker thread number
Add a sysfs entry to control running workqueue thread number. If
group_thread_cnt is set to 0, we will disable workqueue offload handling of
stripes.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 16:56:52 +10:00
Shaohua Li
851c30c9ba raid5: offload stripe handle to workqueue
This is another attempt to create multiple threads to handle raid5 stripes.
This time I use workqueue.

raid5 handles request (especially write) in stripe unit. A stripe is page size
aligned/long and acrosses all disks. Writing to any disk sector, raid5 runs a
state machine for the corresponding stripe, which includes reading some disks
of the stripe, calculating parity, and writing some disks of the stripe. The
state machine is running in raid5d thread currently. Since there is only one
thread, it doesn't scale well for high speed storage. An obvious solution is
multi-threading.

To get better performance, we have some requirements:
a. locality. stripe corresponding to request submitted from one cpu is better
handled in thread in local cpu or local node. local cpu is preferred but some
times could be a bottleneck, for example, parity calculation is too heavy.
local node running has wide adaptability.
b. configurablity. Different setup of raid5 array might need diffent
configuration. Especially the thread number. More threads don't always mean
better performance because of lock contentions.

My original implementation is creating some kernel threads. There are
interfaces to control which cpu's stripe each thread should handle. And
userspace can set affinity of the threads. This provides biggest flexibility
and configurability. But it's hard to use and apparently a new thread pool
implementation is disfavor.

Recent workqueue improvement is quite promising. unbound workqueue will be
bound to numa node. If WQ_SYSFS is set in workqueue, there are sysfs option to
do affinity setting. For example, we can only include one HT sibling in
affinity. Since work is non-reentrant by default, and we can control running
thread number by limiting dispatched work_struct number.

In this patch, I created several stripe worker group. A group is a numa node.
stripes from cpus of one node will be added to a group list. Workqueue thread
of one node will only handle stripes of worker group of the node. In this way,
stripe handling has numa node locality. And as I said, we can control thread
number by limiting dispatched work_struct number.

The work_struct callback function handles several stripes in one run. A typical
work queue usage is to run one unit in each work_struct. In raid5 case, the
unit is a stripe. But we can't do that:
a. Though handling a stripe doesn't need lock because of reference accounting
and stripe isn't in any list, queuing a work_struct for each stripe will make
workqueue lock contended very heavily.
b. blk_start_plug()/blk_finish_plug() should surround stripe handle, as we
might dispatch request. If each work_struct only handles one stripe, such block
plug is meaningless.

This implementation can't do very fine grained configuration. But the numa
binding is most popular usage model, should be enough for most workloads.

Note: since we have only one stripe queue, switching to multi-thread might
decrease request size dispatching down to low level layer. The impact depends
on thread number, raid configuration and workload. So multi-thread raid5 might
not be proper for all setups.

Changes V1 -> V2:
1. remove WQ_NON_REENTRANT
2. disabling multi-threading by default
3. Add more descriptions in changelog

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 16:46:38 +10:00
Shaohua Li
d265d9dc1d raid5: fix stripe release order
patch "make release_stripe lockless" changes the order stripes are released.
Originally I thought block layer can take care of request merge, but it appears
there are still some requests not merged. It's easy to fix the order.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 16:36:26 +10:00
Shaohua Li
773ca82fa1 raid5: make release_stripe lockless
release_stripe still has big lock contention. We just add the stripe to a llist
without taking device_lock. We let the raid5d thread to do the real stripe
release, which must hold device_lock anyway. In this way, release_stripe
doesn't hold any locks.

The side effect is the released stripes order is changed. But sounds not a big
deal, stripes are never handled in order. And I thought block layer can already
do nice request merge, which means order isn't that important.

I kept the unplug release batch, which is unnecessary with this patch from lock
contention avoid point of view, and actually if we delete it, the stripe_head
release_list and lru can share storage. But the unplug release batch is also
helpful for request merge. We probably can delay wakeup raid5d till unplug, but
I'm still afraid of the case which raid5d is running.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-28 11:55:53 +10:00
NeilBrown
260fa034ef md: avoid deadlock when dirty buffers during md_stop.
When the last process closes /dev/mdX sync_blockdev will be called so
that all buffers get flushed.
So if it is then opened for the STOP_ARRAY ioctl to be sent there will
be nothing to flush.

However if we open /dev/mdX in order to send the STOP_ARRAY ioctl just
moments before some other process which was writing closes their file
descriptor, then there won't be a 'last close' and the buffers might
not get flushed.

So do_md_stop() calls sync_blockdev().  However at this point it is
holding ->reconfig_mutex.  So if the array is currently 'clean' then
the writes from sync_blockdev() will not complete until the array
can be marked dirty and that won't happen until some other thread
can get ->reconfig_mutex.  So we deadlock.

We need to move the sync_blockdev() call to before we take
->reconfig_mutex.
However then some other thread could open /dev/mdX and write to it
after we call sync_blockdev() and before we actually stop the array.
This can leave dirty data in the page cache which is awkward.

So introduce new flag MD_STILL_CLOSED.  Set it before calling
sync_blockdev(), clear it if anyone does open the file, and abort the
STOP_ARRAY attempt if it gets set before we lock against further
opens.

It is still possible to get problems if you open /dev/mdX, write to
it, then issue the STOP_ARRAY ioctl.  Just don't do that.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:45:00 +10:00
NeilBrown
7a0a5355cb md: Don't test all of mddev->flags at once.
mddev->flags is mostly used to record if an update of the
metadata is needed.  Sometimes the whole field is tested
instead of just the important bits.  This makes it difficult
to introduce more state bits.

So replace all bare tests of mddev->flags with tests for the bits
that actually need testing.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:28:23 +10:00
Dave Jones
c9ad020fec md: Fix apparent cut-and-paste error in super_90_validate
Setting a variable to itself probably wasn't the intention here.

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:06:17 +10:00
NeilBrown
275c51c4e3 md: fix safe_mode buglet.
Whe we set the safe_mode_timeout to a smaller value we trigger a timeout
immediately - otherwise the small value might not be honoured.
However if the previous timeout was 0 meaning "no timeout", we didn't.
This would mean that no timeout happens until the next write completes,
which could be a long time.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:05:43 +10:00
NeilBrown
60559da4d8 md: don't call md_allow_write in get_bitmap_file.
There is no really need as GFP_NOIO is very likely sufficient,
and failure is not catastrophic.

Calling md_allow_write here will convert a read-auto array to
read/write which could be confusing when you are just performing
a read operation.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-08-27 16:05:32 +10:00
Hannes Reinecke
7e782af576 [SCSI] Return ENODATA on medium error
When a medium error is detected the SCSI stack should return
ENODATA to the upper layers.

[jejb: fix whitespace error]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-08-23 12:54:53 -04:00
Joe Thornber
f722063ee0 dm space map: optimise sm_ll_dec and sm_ll_inc
Prior to this patch these methods did a lookup followed by an insert.
Instead they now call a common mutate function that adjusts the value
according to a callback function.  This avoids traversing the data
structures twice and hence improves performance.

Also factor out sm_ll_lookup_big_ref_count() for use by both
sm_ll_lookup() and sm_ll_mutate().

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-08-23 09:02:14 -04:00
Joe Thornber
04f17c802f dm btree: prefetch child nodes when walking tree for a dm_btree_del
dm-btree now takes advantage of dm-bufio's ability to prefetch data via
dm_bm_prefetch().  Prior to this change many btree node visits were
causing a synchronous read.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-08-23 09:02:14 -04:00
Joe Thornber
cd5acf0b44 dm btree: use pop_frame in dm_btree_del to cleanup code
Remove a visited leaf straight away from the stack, rather than
marking all it's children as visited and letting it get removed on the
next iteration.  May also offer a micro optimisation in dm_btree_del.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-08-23 09:02:14 -04:00
Mike Snitzer
c9ec5d7c7b dm cache: eliminate holes in cache structure
Reorder members in the cache structure to eliminate 6 out of 7 holes
(reclaiming 24 bytes).  Also, the 'worker' and 'waker' members no longer
straddle cachelines.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-23 09:02:14 -04:00
Mike Snitzer
f610937214 dm cache: fix stacking of geometry limits
Do not blindly override the queue limits (specifically io_min and
io_opt).  Allow traditional stacking of these limits if io_opt is a
factor of the cache's data block size.

Without this patch mkfs.xfs does not recognize the cache device's
provided limits as a useful geometry (e.g. raid) so these hints are
ignored.  This was due to setting io_min to a useless value.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-23 09:02:14 -04:00
Mike Snitzer
0cc67cd9c5 dm thin: fix stacking of geometry limits
Do not blindly override the queue limits (specifically io_min and
io_opt).  Allow traditional stacking of these limits if io_opt is a
factor of the thin-pool's data block size.

Without this patch mkfs.xfs does not recognize the thin device's
provided limits as a useful geometry (e.g. raid) so these hints are
ignored.  This was due to setting io_min to a useless value.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-23 09:02:14 -04:00
Mike Snitzer
0547304463 dm cache: add data block size limits to code and Documentation
Place upper bound on the cache's data block size (1GB).

Inform users that the data block size can't be any arbitrary number,
i.e. its value must be between 32KB and 1GB.  Also, it should be a
multiple of 32KB.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-23 09:02:13 -04:00
Tejun Heo
670368a8dd dm: stop using WQ_NON_REENTRANT
dbf2576e37 ("workqueue: make all workqueues non-reentrant") made
WQ_NON_REENTRANT no-op and the flag is going away.  Remove its usages.

This patch doesn't introduce any behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-23 09:02:13 -04:00
Geert Uytterhoeven
b936bf8b78 dm cache: avoid conflicting remove_mapping() in mq policy
On sparc32, which includes <linux/swap.h> from <asm/pgtable_32.h>:

drivers/md/dm-cache-policy-mq.c:962:13: error: conflicting types for 'remove_mapping'
include/linux/swap.h:285:12: note: previous declaration of 'remove_mapping' was here

As mq_remove_mapping() already exists, and the local remove_mapping() is
used only once, inline it manually to avoid the conflict.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair Kergon <agk@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
2013-08-16 15:56:51 -04:00
Linus Torvalds
c271f5bc9a 2 more bugfixes for md in 3.11
Both marked for -stable, both since 3.3.  I guess I should spend more
 time testing...
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Merge tag 'md/3.11-fixes' of git://neil.brown.name/md

Pull md fixes from Neil Brown:
 "Two more bugfixes for md in 3.11

  Both marked for -stable, both since 3.3.  I guess I should spend more
  time testing..."

* tag 'md/3.11-fixes' of git://neil.brown.name/md:
  md/raid5: fix interaction of 'replace' and 'recovery'.
  md/raid10: remove use-after-free bug.
2013-07-26 11:20:10 -07:00
NeilBrown
f94c0b6658 md/raid5: fix interaction of 'replace' and 'recovery'.
If a device in a RAID4/5/6 is being replaced while another is being
recovered, then the writes to the replacement device currently don't
happen, resulting in corruption when the replacement completes and the
new drive takes over.

This is because the replacement writes are only triggered when
's.replacing' is set and not when the similar 's.sync' is set (which
is the case during resync and recovery - it means all devices need to
be read).

So schedule those writes when s.replacing is set as well.

In this case we cannot use "STRIPE_INSYNC" to record that the
replacement has happened as that is needed for recording that any
parity calculation is complete.  So introduce STRIPE_REPLACED to
record if the replacement has happened.

For safety we should also check that STRIPE_COMPUTE_RUN is not set.
This has a similar effect to the "s.locked == 0" test.  The latter
ensure that now IO has been flagged but not started.  The former
checks if any parity calculation has been flagged by not started.
We must wait for both of these to complete before triggering the
'replace'.

Add a similar test to the subsequent check for "are we finished yet".
This possibly isn't needed (is subsumed in the STRIPE_INSYNC test),
but it makes it more obvious that the REPLACE will happen before we
think we are finished.

Finally if a NeedReplace device is not UPTODATE then that is an
error.  We really must trigger a warning.

This bug was introduced in commit 9a3e1101b8
(md/raid5:  detect and handle replacements during recovery.)
which introduced replacement for raid5.
That was in 3.3-rc3, so any stable kernel since then would benefit
from this fix.

Cc: stable@vger.kernel.org (3.3+)
Reported-by: qindehua <13691222965@163.com>
Tested-by: qindehua <qindehua@163.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-25 16:46:57 +10:00
NeilBrown
0eb25bb027 md/raid10: remove use-after-free bug.
We always need to be careful when calling generic_make_request, as it
can start a chain of events which might free something that we are
using.

Here is one place I wasn't careful enough.  If the wbio2 is not in
use, then it might get freed at the first generic_make_request call.
So perform all necessary tests first.

This bug was introduced in 3.3-rc3 (24afd80d99) and can cause an
oops, so fix is suitable for any -stable since then.

Cc: stable@vger.kernel.org (3.3+)
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-25 16:46:53 +10:00
Linus Torvalds
d4c90b1b9f Merge branch 'for-3.11/drivers' of git://git.kernel.dk/linux-block
Pull block IO driver bits from Jens Axboe:
 "As I mentioned in the core block pull request, due to real life
  circumstances the driver pull request would be late.  Now it looks
  like -rc2 late...  On the plus side, apart form the rsxx update, these
  are all things that I could argue could go in later in the cycle as
  they are fixes and not features.  So even though things are late, it's
  not ALL bad.

  The pull request contains:

   - Updates to bcache, all bug fixes, from Kent.

   - A pile of drbd bug fixes (no big features this time!).

   - xen blk front/back fixes.

   - rsxx driver updates, some of them deferred form 3.10.  So should be
     well cooked by now"

* 'for-3.11/drivers' of git://git.kernel.dk/linux-block: (63 commits)
  bcache: Allocation kthread fixes
  bcache: Fix GC_SECTORS_USED() calculation
  bcache: Journal replay fix
  bcache: Shutdown fix
  bcache: Fix a sysfs splat on shutdown
  bcache: Advertise that flushes are supported
  bcache: check for allocation failures
  bcache: Fix a dumb race
  bcache: Use standard utility code
  bcache: Update email address
  bcache: Delete fuzz tester
  bcache: Document shrinker reserve better
  bcache: FUA fixes
  drbd: Allow online change of al-stripes and al-stripe-size
  drbd: Constants should be UPPERCASE
  drbd: Ignore the exit code of a fence-peer handler if it returns too late
  drbd: Fix rcu_read_lock balance on error path
  drbd: fix error return code in drbd_init()
  drbd: Do not sleep inside rcu
  bcache: Refresh usage docs
  ...
2013-07-22 19:02:52 -07:00
NeilBrown
30bc9b5387 md/raid1: fix bio handling problems in process_checks()
Recent change to use bio_copy_data() in raid1 when repairing
an array is faulty.

The underlying may have changed the bio in various ways using
bio_advance and these need to be undone not just for the 'sbio' which
is being copied to, but also the 'pbio' (primary) which is being
copied from.

So perform the reset on all bios that were read from and do it early.

This also ensure that the sbio->bi_io_vec[j].bv_len passed to
memcmp is correct.

This fixes a crash during a 'check' of a RAID1 array.  The crash was
introduced in 3.10 so this is suitable for 3.10-stable.

Cc: stable@vger.kernel.org (3.10)
Reported-by: Joe Lawrence <joe.lawrence@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-18 14:18:04 +10:00
NeilBrown
5024c29831 md: Remove recent change which allows devices to skip recovery.
commit 7ceb17e87b
    md: Allow devices to be re-added to a read-only array.

allowed a bit more than just that.  It also allows devices to be added
to a read-write array and to end up skipping recovery.

This patch removes the offending piece of code pending a rewrite for a
subsequent release.

More specifically:
 If the array has a bitmap, then the device will still need a bitmap
 based resync ('saved_raid_disk' is set under different conditions
 is a bitmap is present).
 If the array doesn't have a bitmap, then this is correct as long as
 nothing has been written to the array since the metadata was checked
 by ->validate_super.  However there is no locking to ensure that there
 was no write.

Bug was introduced in 3.10 and causes data corruption so
patch is suitable for 3.10-stable.

Cc: stable@vger.kernel.org (3.10)
Reported-by: Joe Lawrence <joe.lawrence@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-18 14:18:03 +10:00
NeilBrown
7bb23c4934 md/raid10: fix two problems with RAID10 resync.
1/ When an different between blocks is found, data is copied from
   one bio to the other.  However bv_len is used as the length to
   copy and this could be zero.  So use r10_bio->sectors to calculate
   length instead.
   Using bv_len was probably always a bit dubious, but the introduction
   of bio_advance made it much more likely to be a problem.

2/ When preparing some blocks for sync, we don't set BIO_UPTODATE
   except on bios that we schedule for a read.  This ensures that
   missing/failed devices don't confuse the loop at the top of
   sync_request write.
   Commit 8be185f2c9 "raid10: Use bio_reset()"
   removed a loop which set BIO_UPTDATE on all appropriate bios.
   So we need to re-add that flag.

These bugs were introduced in 3.10, so this patch is suitable for
3.10-stable, and can remove a potential for data corruption.

Cc: stable@vger.kernel.org (3.10)
Reported-by: Brassow Jonathan <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-18 14:18:01 +10:00
Kent Overstreet
79826c35eb bcache: Allocation kthread fixes
The alloc kthread should've been using try_to_freeze() - and also there
was the potential for the alloc kthread to get woken up after it had
shut down, which would have been bad.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-07-12 00:22:49 -07:00
Kent Overstreet
29ebf465b9 bcache: Fix GC_SECTORS_USED() calculation
Part of the job of garbage collection is to add up however many sectors
of live data it finds in each bucket, but that doesn't work very well if
it doesn't reset GC_SECTORS_USED() when it starts. Whoops.

This wouldn't have broken anything horribly, but allocation tries to
preferentially reclaim buckets that are mostly empty and that's not
gonna work with an incorrect GC_SECTORS_USED() value.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:48 -07:00
Kent Overstreet
faa5673617 bcache: Journal replay fix
The journal replay code starts by finding something that looks like a
valid journal entry, then it does a binary search over the unchecked
region of the journal for the journal entries with the highest sequence
numbers.

Trouble is, the logic was wrong - journal_read_bucket() returns true if
it found journal entries we need, but if the range of journal entries
we're looking for loops around the end of the journal - in that case
journal_read_bucket() could return true when it hadn't found the highest
sequence number we'd seen yet, and in that case the binary search did
the wrong thing. Whoops.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:48 -07:00
Kent Overstreet
5caa52afc5 bcache: Shutdown fix
Stopping a cache set is supposed to make it stop attached backing
devices, but somewhere along the way that code got lost. Fixing this
mainly has the effect of fixing our reboot notifier.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:47 -07:00
Kent Overstreet
c9502ea442 bcache: Fix a sysfs splat on shutdown
If we stopped a bcache device when we were already detaching (or
something like that), bcache_device_unlink() would try to remove a
symlink from sysfs that was already gone because the bcache dev kobject
had already been removed from sysfs.

So keep track of whether we've removed stuff from sysfs.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:47 -07:00
Kent Overstreet
54d12f2b4f bcache: Advertise that flushes are supported
Whoops - bcache's flush/FUA was mostly correct, but flushes get filtered
out unless we say we support them...

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:46 -07:00
Dan Carpenter
d2a65ce2ac bcache: check for allocation failures
There is a missing NULL check after the kzalloc().

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
2013-07-12 00:22:46 -07:00
Kent Overstreet
6aa8f1a6ca bcache: Fix a dumb race
In the far-too-complicated closure code - closures can have destructors,
for probably dubious reasons; they get run after the closure is no
longer waiting on anything but before dropping the parent ref, intended
just for freeing whatever memory the closure is embedded in.

Trouble is, when remaining goes to 0 and we've got nothing more to run -
we also have to unlock the closure, setting remaining to -1. If there's
a destructor, that unlock isn't doing anything - nobody could be trying
to lock it if we're about to free it - but if the unlock _is needed...
that check for a destructor was racy. Argh.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
2013-07-12 00:22:33 -07:00
Linus Torvalds
9903883f1d Add a device-mapper target called dm-switch to provide a multipath
framework for storage arrays that dynamically reconfigure their
 preferred paths for different device regions.
 
 Fix a bug in the verity target that prevented its use with some
 specific sizes of devices.
 
 Improve some locking mechanisms in the device-mapper core and bufio.
 
 Add Mike Snitzer as a device-mapper maintainer.
 
 A few more clean-ups and fixes.
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Merge tag 'dm-3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull device-mapper changes from Alasdair G Kergon:
 "Add a device-mapper target called dm-switch to provide a multipath
  framework for storage arrays that dynamically reconfigure their
  preferred paths for different device regions.

  Fix a bug in the verity target that prevented its use with some
  specific sizes of devices.

  Improve some locking mechanisms in the device-mapper core and bufio.

  Add Mike Snitzer as a device-mapper maintainer.

  A few more clean-ups and fixes"

* tag 'dm-3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm: add switch target
  dm: update maintainers
  dm: optimize reorder structure
  dm: optimize use SRCU and RCU
  dm bufio: submit writes outside lock
  dm cache: fix arm link errors with inline
  dm verity: use __ffs and __fls
  dm flakey: correct ctr alloc failure mesg
  dm verity: remove pointless comparison
  dm: use __GFP_HIGHMEM in __vmalloc
  dm verity: fix inability to use a few specific devices sizes
  dm ioctl: set noio flag to avoid __vmalloc deadlock
  dm mpath: fix ioctl deadlock when no paths
2013-07-11 13:05:40 -07:00
Jim Ramsay
9d0eb0ab43 dm: add switch target
dm-switch is a new target that maps IO to underlying block devices
efficiently when there is a large number of fixed-sized address regions
but there is no simple pattern to allow for a compact mapping
representation such as dm-stripe.

Though we have developed this target for a specific storage device, Dell
EqualLogic, we have made an effort to keep it as general purpose as
possible in the hope that others may benefit.

Originally developed by Jim Ramsay. Simplified by Mikulas Patocka.

Signed-off-by: Jim Ramsay <jim_ramsay@dell.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:19 +01:00
Mikulas Patocka
2a7faeb176 dm: optimize reorder structure
This reorder actually improves performance by 20% (from 39.1s to 32.8s)
on x86-64 quad core Opteron.

I have no explanation for this, possibly it makes some other entries are
better cache-aligned.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:18 +01:00
Mikulas Patocka
83d5e5b0af dm: optimize use SRCU and RCU
This patch removes "io_lock" and "map_lock" in struct mapped_device and
"holders" in struct dm_table and replaces these mechanisms with
sleepable-rcu.

Previously, the code would call "dm_get_live_table" and "dm_table_put" to
get and release table. Now, the code is changed to call "dm_get_live_table"
and "dm_put_live_table". dm_get_live_table locks sleepable-rcu and
dm_put_live_table unlocks it.

dm_get_live_table_fast/dm_put_live_table_fast can be used instead of
dm_get_live_table/dm_put_live_table. These *_fast functions use
non-sleepable RCU, so the caller must not block between them.

If the code changes active or inactive dm table, it must call
dm_sync_table before destroying the old table.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:18 +01:00
Mikulas Patocka
2480945cd4 dm bufio: submit writes outside lock
This patch changes dm-bufio so that it submits write I/Os outside of the
lock. If the number of submitted buffers is greater than the number of
requests on the target queue, submit_bio blocks. We want to block outside
of the lock to improve latency of other threads that may need the lock.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:18 +01:00
Mikulas Patocka
43aeaa2957 dm cache: fix arm link errors with inline
Use __always_inline to avoid a link failure with gcc 4.6 on ARM.
gcc 4.7 is OK.

It creates a function block_div.part.8, it references __udivdi3 and
__umoddi3 and it is never called. The references to __udivdi3 and
__umoddi3 cause a link failure.

Reported-by: Rob Herring <robherring2@gmail.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:17 +01:00
Mikulas Patocka
553d8fe029 dm verity: use __ffs and __fls
This patch changes ffs() to __ffs() and fls() to __fls() which don't add
one to the result.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:17 +01:00
Alasdair G Kergon
75e3a0f55b dm flakey: correct ctr alloc failure mesg
Remove the reference to the "linear" target from the error message
issued when allocation fails in the flakey target.

Cc: Robin Dong <sanbai@taobao.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:17 +01:00
Mikulas Patocka
5d8be84397 dm verity: remove pointless comparison
Remove num < 0 test in verity_ctr because num is unsigned.
(Found by Coverity.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:17 +01:00
Mikulas Patocka
220cd058d9 dm: use __GFP_HIGHMEM in __vmalloc
Use __GFP_HIGHMEM in __vmalloc.

Pages allocated with __vmalloc can be allocated in high memory that is not
directly mapped to kernel space, so use __GFP_HIGHMEM just like vmalloc
does. This patch reduces memory pressure slightly because pages can be
allocated in the high zone.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:16 +01:00
Mikulas Patocka
b1bf2de072 dm verity: fix inability to use a few specific devices sizes
Fix a boundary condition that caused failure for certain device sizes.

The problem is reported at
  http://code.google.com/p/cryptsetup/issues/detail?id=160

For certain device sizes the number of hashes at a specific level was
calculated incorrectly.

It happens for example for a device with data and metadata block size 4096
that has 16385 blocks and algorithm sha256.

The user can test if he is affected by this bug by running the
"veritysetup verify" command and also by activating the dm-verity kernel
driver and reading the whole block device. If it passes without an error,
then the user is not affected.

The condition for the bug is:

Split the total number of data blocks (data_block_bits) into bit strings,
each string has hash_per_block_bits bits. hash_per_block_bits is
rounddown(log2(metadata_block_size/hash_digest_size)). Equivalently, you
can say that you convert data_blocks_bits to 2^hash_per_block_bits base.

If there some zero bit string below the most significant bit string and at
least one bit below this zero bit string is set, then the bug happens.

The same bug exists in the userspace veritysetup tool, so you must use
fixed veritysetup too if you want to use devices that are affected by
this boundary condition.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # 3.4+
Cc: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:16 +01:00
Mikulas Patocka
1c0e883e86 dm ioctl: set noio flag to avoid __vmalloc deadlock
Set noio flag while calling __vmalloc() because it doesn't fully respect
gfp flags to avoid a possible deadlock (see commit
502624bdad).

This should be backported to stable kernels 3.8 and newer. The kernel 3.8
doesn't have memalloc_noio_save(), so we should set and restore process
flag PF_MEMALLOC instead.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:15 +01:00
Hannes Reinecke
6c182cd88d dm mpath: fix ioctl deadlock when no paths
When multipath needs to retry an ioctl the reference to the
current live table needs to be dropped. Otherwise a deadlock
occurs when all paths are down:
- dm_blk_ioctl takes a reference to the current table
  and spins in multipath_ioctl().
- A new table is being loaded, but upon resume the process
  hangs in dm_table_destroy() waiting for references to
  drop to zero.

With this patch the reference to the old table is dropped
prior to retry, thereby avoiding the deadlock.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10 23:41:15 +01:00
Linus Torvalds
80cc38b163 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "The usual stuff from trivial tree"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
  treewide: relase -> release
  Documentation/cgroups/memory.txt: fix stat file documentation
  sysctl/net.txt: delete reference to obsolete 2.4.x kernel
  spinlock_api_smp.h: fix preprocessor comments
  treewide: Fix typo in printk
  doc: device tree: clarify stuff in usage-model.txt.
  open firmware: "/aliasas" -> "/aliases"
  md: bcache: Fixed a typo with the word 'arithmetic'
  irq/generic-chip: fix a few kernel-doc entries
  frv: Convert use of typedef ctl_table to struct ctl_table
  sgi: xpc: Convert use of typedef ctl_table to struct ctl_table
  doc: clk: Fix incorrect wording
  Documentation/arm/IXP4xx fix a typo
  Documentation/networking/ieee802154 fix a typo
  Documentation/DocBook/media/v4l fix a typo
  Documentation/video4linux/si476x.txt fix a typo
  Documentation/virtual/kvm/api.txt fix a typo
  Documentation/early-userspace/README fix a typo
  Documentation/video4linux/soc-camera.txt fix a typo
  lguest: fix CONFIG_PAE -> CONFIG_x86_PAE in comment
  ...
2013-07-04 11:40:58 -07:00
NeilBrown
1376512065 md/raid10: fix bug which causes all RAID10 reshapes to move no data.
The recent comment:
commit 7e83ccbecd
    md/raid10: Allow skipping recovery when clean arrays are assembled

Causes raid10 to skip a recovery in certain cases where it is safe to
do so.  Unfortunately it also causes a reshape to be skipped which is
never safe.  The result is that an attempt to reshape a RAID10 will
appear to complete instantly, but no data will have been moves so the
array will now contain garbage.
(If nothing is written, you can recovery by simple performing the
reverse reshape which will also complete instantly).

Bug was introduced in 3.10, so this is suitable for 3.10-stable.

Cc: stable@vger.kernel.org (3.10)
Cc: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-04 16:42:57 +10:00
NeilBrown
fdcfbbb653 md/raid5: allow 5-device RAID6 to be reshaped to 4-device.
There is a bug in 'check_reshape' for raid5.c  To checks
that the new minimum number of devices is large enough (which is
good), but it does so also after the reshape has started (bad).

This is bad because
 - the calculation is now wrong as mddev->raid_disks has changed
   already, and
 - it is pointless because it is now too late to stop.

So only perform that test when reshape has not been committed to.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-04 16:42:52 +10:00
NeilBrown
78eaa0d4cb md/raid10: fix two bugs affecting RAID10 reshape.
1/ If a RAID10 is being reshaped to a fewer number of devices
 and is stopped while this is ongoing, then when the array is
 reassembled the 'mirrors' array will be allocated too small.
 This will lead to an access error or memory corruption.

2/ A sanity test for a reshaping RAID10 array is restarted
 is slightly incorrect.

Due to the first bug, this is suitable for any -stable
kernel since 3.5 where this code was introduced.

Cc: stable@vger.kernel.org (v3.5+)
Signed-off-by: NeilBrown <neilb@suse.de>
2013-07-03 09:43:28 +10:00
Kent Overstreet
8e51e414a3 bcache: Use standard utility code
Some of bcache's utility code has made it into the rest of the kernel,
so drop the bcache versions.

Bcache used to have a workaround for allocating from a bio set under
generic_make_request() (if you allocated more than once, the bios you
already allocated would get stuck on current->bio_list when you
submitted, and you'd risk deadlock) - bcache would mask out __GFP_WAIT
when allocating bios under generic_make_request() so that allocation
could fail and it could retry from workqueue. But bio_alloc_bioset() has
a workaround now, so we can drop this hack and the associated error
handling.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-07-01 14:43:53 -07:00
Kent Overstreet
f3059a5461 bcache: Delete fuzz tester
This code has rotted and it hasn't been used in ages anyways.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-07-01 14:43:48 -07:00
Kent Overstreet
36c9ea9837 bcache: Document shrinker reserve better
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2013-07-01 14:42:48 -07:00
Kent Overstreet
e49c7c374e bcache: FUA fixes
Journal writes need to be marked FUA, not just REQ_FLUSH. And btree node
writes have... weird ordering requirements.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-07-01 14:42:47 -07:00
Gabriel de Perthuis
ab9e14002e bcache: Send label uevents
Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 21:58:06 -07:00
Gabriel de Perthuis
a25c32bede bcache: Send a uevent with a cached device's UUID
Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
2013-06-26 21:58:05 -07:00
Kent Overstreet
72c270612b bcache: Write out full stripes
Now that we're tracking dirty data per stripe, we can add two
optimizations for raid5/6:

 * If a stripe is already dirty, force writes to that stripe to
   writeback mode - to help build up full stripes of dirty data

 * When flushing dirty data, preferentially write out full stripes first
   if there are any.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 21:58:04 -07:00
Kent Overstreet
279afbad4e bcache: Track dirty data by stripe
To make background writeback aware of raid5/6 stripes, we first need to
track the amount of dirty data within each stripe - we do this by
breaking up the existing sectors_dirty into per stripe atomic_ts

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 21:57:23 -07:00
Kent Overstreet
444fc0b6b1 bcache: Initialize sectors_dirty when attaching
Previously, dirty_data wouldn't get initialized until the first garbage
collection... which was a bit of a problem for background writeback (as
the PD controller keys off of it) and also confusing for users.

This is also prep work for making background writeback aware of raid5/6
stripes.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:16 -07:00
Kent Overstreet
6ded34d1a5 bcache: Improve lazy sorting
The old lazy sorting code was kind of hacky - rewrite in a way that
mathematically makes more sense; the idea is that the size of the sets
of keys in a btree node should increase by a more or less fixed ratio
from smallest to biggest.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:16 -07:00
Kent Overstreet
85b1492ee1 bcache: Rip out pkey()/pbtree()
Old gcc doesnt like the struct hack, and it is kind of ugly. So finish
off the work to convert pr_debug() statements to tracepoints, and delete
pkey()/pbtree().

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:15 -07:00
Kent Overstreet
c37511b863 bcache: Fix/revamp tracepoints
The tracepoints were reworked to be more sensible, and fixed a null
pointer deref in one of the tracepoints.

Converted some of the pr_debug()s to tracepoints - this is partly a
performance optimization; it used to be that with DEBUG or
CONFIG_DYNAMIC_DEBUG pr_debug() was an empty macro; but at some point it
was changed to an empty inline function.

Some of the pr_debug() statements had rather expensive function calls as
part of the arguments, so this code was getting run unnecessarily even
on non debug kernels - in some fast paths, too.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:15 -07:00
Kent Overstreet
5794351146 bcache: Refactor btree io
The most significant change is that btree reads are now done
synchronously, instead of asynchronously and doing the post read stuff
from a workqueue.

This was originally done because we can't block on IO under
generic_make_request(). But - we already have a mechanism to punt cache
lookups to workqueue if needed, so if we just use that we don't have to
deal with the complexity of doing things asynchronously.

The main benefit is this makes the locking situation saner; we can hold
our write lock on the btree node until we're finished reading it, and we
don't need that btree_node_read_done() flag anymore.

Also, for writes, btree_write() was broken out into btree_node_write()
and btree_leaf_dirty() - the old code with the boolean argument was dumb
and confusing.

The prio_blocked mechanism was improved a bit too, now the only counter
is in struct btree_write, we don't mess with transfering a count from
struct btree anymore.

This required changing garbage collection to block prios at the start
and unblock when it finishes, which is cleaner than what it was doing
anyways (the old code had mostly the same effect, but was doing it in a
convoluted way)

And the btree iter btree_node_read_done() uses was converted to a real
mempool.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:14 -07:00
Kent Overstreet
119ba0f828 bcache: Convert allocator thread to kthread
Using a workqueue when we just want a single thread is a bit silly.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:09:13 -07:00
Gabriel de Perthuis
a9dd53adbb bcache: Warn when a device is already registered.
Signed-off-by: Gabriel de Perthuis <g2p.code+bcache@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:08:52 -07:00
Kent Overstreet
bbc77aa7fb bcache: fix a spurious gcc complaint, use scnprintf
An old version of gcc was complaining about using a const int as the
size of a stack allocated array. Which should be fine - but using
ARRAY_SIZE() is better, anyways.

Also, refactor the code to use scnprintf().

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:06:33 -07:00
Kumar Amit Mehta
5c694129c8 md: bcache: io.c: fix a potential NULL pointer dereference
bio_alloc_bioset returns NULL on failure. This fix adds a missing check
for potential NULL pointer dereferencing.

Signed-off-by: Kumar Amit Mehta <gmate.amit@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-06-26 17:06:19 -07:00
Jonathan Brassow
c4a3955145 MD: Remember the last sync operation that was performed
MD:  Remember the last sync operation that was performed

This patch adds a field to the mddev structure to track the last
sync operation that was performed.  This is especially useful when
it comes to what is recorded in mismatch_cnt in sysfs.  If the
last operation was "data-check", then it reports the number of
descrepancies found by the user-initiated check.  If it was a
"repair" operation, then it is reporting the number of
descrepancies repaired.  etc.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-26 12:38:24 +10:00
NeilBrown
eea136d69f md: fix buglet in RAID5 -> RAID0 conversion.
RAID5 uses a 'per-array' value for the 'size' of each device.
RAID0 uses a 'per-device' value - it can be different for each device.

When converting a RAID5 to a RAID0 we must ensure that the per-device
size of each device matches the per-array size for the RAID5, else
the array will change size.

If the metadata cannot record a changed per-device size (as is the
case with v0.90 metadata) the array could get bigger on restart.  This
does not cause data corruption, so it not a big issue and is mainly
yet another a reason to not use 0.90.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-26 12:38:19 +10:00
Phil Viana
48a73025cb md: bcache: Fixed a typo with the word 'arithmetic'
The word 'arithmetic' was typed as 'arithmatic'

Signed-off-by: Phil Viana <phillip.l.viana@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-06-18 13:41:16 +02:00
NeilBrown
725d6e579f md/raid10: check In_sync flag in 'enough()'.
It isn't really enough to check that the rdev is present, we need to
also be sure that the device is still In_sync.

Doing this requires using rcu_dereference to access the rdev, and
holding the rcu_read_lock() to ensure the rdev doesn't disappear while
we look at it.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:27 +10:00
NeilBrown
635f6416a2 md/raid10: locking changes for 'enough()'.
As 'enough' accesses conf->prev and conf->geo, which can change
spontanously, it should guard against changes.
This can be done with device_lock as start_reshape holds device_lock
while updating 'geo' and end_reshape holds it while updating 'prev'.

So 'error' needs to hold 'device_lock'.

On the other hand, raid10_end_read_request knows which of the two it
really wants to access, and as it is an active request on that one,
the value cannot change underneath it.

So change _enough to take flag rather than a pointer, pass the
appropriate flag from raid10_end_read_request(), and remove the locking.

All other calls to 'enough' are made with reconfig_mutex held, so
neither 'prev' nor 'geo' can change.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:27 +10:00
Jingoo Han
b29bebd66d md: replace strict_strto*() with kstrto*()
The usage of strict_strtoul() is not preferred, because
strict_strtoul() is obsolete. Thus, kstrtoul() should be
used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:26 +10:00
Hannes Reinecke
90f5f7ad4f md: Wait for md_check_recovery before attempting device removal.
When a device has failed, it needs to be removed from the personality
module before it can be removed from the array as a whole.
The first step is performed by md_check_recovery() which is called
from the raid management thread.

So when a HOT_REMOVE ioctl arrives, wait briefly for md_check_recovery
to have run.  This increases the chance that the ioctl will succeed.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Neil Brown <nfbrown@suse.de>
2013-06-14 08:10:26 +10:00
NeilBrown
3f6bbd3ffd dm-raid: silence compiler warning on rebuilds_per_group.
This doesn't really need to be initialised, but it doesn't hurt,
silences the compiler, and as it is a counter it makes sense for it to
start at zero.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:26 +10:00
Jonathan Brassow
a4dc163a55 DM RAID: Fix raid_resume not reviving failed devices in all cases
DM RAID:  Fix raid_resume not reviving failed devices in all cases

When a device fails in a RAID array, it is marked as Faulty.  Later,
md_check_recovery is called which (through the call chain) calls
'hot_remove_disk' in order to have the personalities remove the device
from use in the array.

Sometimes, it is possible for the array to be suspended before the
personalities get their chance to perform 'hot_remove_disk'.  This is
normally not an issue.  If the array is deactivated, then the failed
device will be noticed when the array is reinstantiated.  If the
array is resumed and the disk is still missing, md_check_recovery will
be called upon resume and 'hot_remove_disk' will be called at that
time.  However, (for dm-raid) if the device has been restored,
a resume on the array would cause it to attempt to revive the device
by calling 'hot_add_disk'.  If 'hot_remove_disk' had not been called,
a situation is then created where the device is thought to concurrently
be the replacement and the device to be replaced.  Thus, the device
is first sync'ed with the rest of the array (because it is the replacement
device) and then marked Faulty and removed from the array (because
it is also the device being replaced).

The solution is to check and see if the device had properly been removed
before the array was suspended.  This is done by seeing whether the
device's 'raid_disk' field is -1 - a condition that implies that
'md_check_recovery -> remove_and_add_spares (where raid_disk is set to -1)
-> hot_remove_disk' has been called.  If 'raid_disk' is not -1, then
'hot_remove_disk' must be called to complete the removal of the previously
faulty device before it can be revived via 'hot_add_disk'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:25 +10:00
Jonathan Brassow
f381e71b04 DM RAID: Break-up untidy function
DM RAID:  Break-up untidy function

Clean-up excessive indentation by moving some code in raid_resume()
into its own function.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:25 +10:00
Jonathan Brassow
9092c02d94 DM RAID: Add ability to restore transiently failed devices on resume
DM RAID: Add ability to restore transiently failed devices on resume

This patch adds code to the resume function to check over the devices
in the RAID array.  If any are found to be marked as failed and their
superblocks can be read, an attempt is made to reintegrate them into
the array.  This allows the user to refresh the array with a simple
suspend and resume of the array - rather than having to load a
completely new table, allocate and initialize all the structures and
throw away the old instantiation.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-14 08:10:24 +10:00
Linus Torvalds
82ea4be61f A few bugfixes for md
Some tagged for -stable.
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Merge tag 'md-3.10-fixes' of git://neil.brown.name/md

Pull md bugfixes from Neil Brown:
 "A few bugfixes for md

  Some tagged for -stable"

* tag 'md-3.10-fixes' of git://neil.brown.name/md:
  md/raid1,5,10: Disable WRITE SAME until a recovery strategy is in place
  md/raid1,raid10: use freeze_array in place of raise_barrier in various places.
  md/raid1: consider WRITE as successful only if at least one non-Faulty and non-rebuilding drive completed it.
  md: md_stop_writes() should always freeze recovery.
2013-06-13 10:13:29 -07:00
H. Peter Anvin
5026d7a9b2 md/raid1,5,10: Disable WRITE SAME until a recovery strategy is in place
There are cases where the kernel will believe that the WRITE SAME
command is supported by a block device which does not, in fact,
support WRITE SAME.  This currently happens for SATA drivers behind a
SAS controller, but there are probably a hundred other ways that can
happen, including drive firmware bugs.

After receiving an error for WRITE SAME the block layer will retry the
request as a plain write of zeroes, but mdraid will consider the
failure as fatal and consider the drive failed.  This has the effect
that all the mirrors containing a specific set of data are each
offlined in very rapid succession resulting in data loss.

However, just bouncing the request back up to the block layer isn't
ideal either, because the whole initial request-retry sequence should
be inside the write bitmap fence, which probably means that md needs
to do its own conversion of WRITE SAME to write zero.

Until the failure scenario has been sorted out, disable WRITE SAME for
raid1, raid5, and raid10.

[neilb: added raid5]

This patch is appropriate for any -stable since 3.7 when write_same
support was added.

Cc: stable@vger.kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-13 14:49:54 +10:00
NeilBrown
e2d5992522 md/raid1,raid10: use freeze_array in place of raise_barrier in various places.
Various places in raid1 and raid10 are calling raise_barrier when they
really should call freeze_array.
The former is only intended to be called from "make_request".
The later has extra checks for 'nr_queued' and makes a call to
flush_pending_writes(), so it is safe to call it from within the
management thread.

Using raise_barrier will sometimes deadlock.  Using freeze_array
should not.

As 'freeze_array' currently expects one request to be pending (in
handle_read_error - the only previous caller), we need to pass
it the number of pending requests (extra) to ignore.

The deadlock was made particularly noticeable by commits
050b66152f (raid10) and 6b740b8d79 (raid1) which
appeared in 3.4, so the fix is appropriate for any -stable
kernel since then.

This patch probably won't apply directly to some early kernels and
will need to be applied by hand.

Cc: stable@vger.kernel.org
Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-13 13:40:48 +10:00
Alex Lyakas
3056e3aec8 md/raid1: consider WRITE as successful only if at least one non-Faulty and non-rebuilding drive completed it.
Without that fix, the following scenario could happen:

- RAID1 with drives A and B; drive B was freshly-added and is rebuilding
- Drive A fails
- WRITE request arrives to the array. It is failed by drive A, so
r1_bio is marked as R1BIO_WriteError, but the rebuilding drive B
succeeds in writing it, so the same r1_bio is marked as
R1BIO_Uptodate.
- r1_bio arrives to handle_write_finished, badblocks are disabled,
md_error()->error() does nothing because we don't fail the last drive
of raid1
- raid_end_bio_io()  calls call_bio_endio()
- As a result, in call_bio_endio():
        if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
                clear_bit(BIO_UPTODATE, &bio->bi_flags);
this code doesn't clear the BIO_UPTODATE flag, and the whole master
WRITE succeeds, back to the upper layer.

So we returned success to the upper layer, even though we had written
the data onto the rebuilding drive only. But when we want to read the
data back, we would not read from the rebuilding drive, so this data
is lost.

[neilb - applied identical change to raid10 as well]

This bug can result in lost data, so it is suitable for any
-stable kernel.

Cc: stable@vger.kernel.org
Signed-off-by: Alex Lyakas <alex@zadarastorage.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-13 13:20:03 +10:00
NeilBrown
6b6204ee92 md: md_stop_writes() should always freeze recovery.
__md_stop_writes() will currently sometimes freeze recovery.
So any caller must be ready for that to happen, and indeed they are.

However if __md_stop_writes() doesn't freeze_recovery, then
a recovery could start before mddev_suspend() is called, which
could be awkward.  This can particularly cause problems or dm-raid.

So change __md_stop_writes() to always freeze recovery.  This is safe
and more predicatable.

Reported-by: Brassow Jonathan <jbrassow@redhat.com>
Tested-by: Brassow Jonathan <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-06-13 13:18:15 +10:00
Linus Torvalds
b2cc9c19e4 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
 "Outside of bcache (which really isn't super big), these are all
  few-liners.  There are a few important fixes in here:

   - Fix blk pm sleeping when holding the queue lock

   - A small collection of bcache fixes that have been done and tested
     since bcache was included in this merge window.

   - A fix for a raid5 regression introduced with the bio changes.

   - Two important fixes for mtip32xx, fixing an oops and potential data
     corruption (or hang) due to wrong bio iteration on stacked devices."

* 'for-linus' of git://git.kernel.dk/linux-block:
  scatterlist: sg_set_buf() argument must be in linear mapping
  raid5: Initialize bi_vcnt
  pktcdvd: silence static checker warning
  block: remove refs to XD disks from documentation
  blkpm: avoid sleep when holding queue lock
  mtip32xx: Correctly handle bio->bi_idx != 0 conditions
  mtip32xx: Fix NULL pointer dereference during module unload
  bcache: Fix error handling in init code
  bcache: clarify free/available/unused space
  bcache: drop "select CLOSURES"
  bcache: Fix incompatible pointer type warning
2013-06-12 16:42:39 -07:00
Kent Overstreet
4997b72ee6 raid5: Initialize bi_vcnt
The patch that converted raid5 to use bio_reset() forgot to initialize
bi_vcnt.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: NeilBrown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Tested-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-05-30 08:44:39 +02:00
Alasdair G Kergon
610bba8b93 dm thin: fix metadata dev resize detection
Fix detection of the need to resize the dm thin metadata device.

The code incorrectly tried to extend the metadata device when it
didn't need to due to a merging error with patch 24347e9 ("dm thin:
detect metadata device resizing").

  device-mapper: transaction manager: couldn't open metadata space map
  device-mapper: thin metadata: tm_open_with_sm failed
  device-mapper: thin: aborting transaction failed
  device-mapper: thin: switching pool to failure mode

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-19 18:57:50 +01:00
Jens Axboe
c0a363f5cf Merge branch 'bcache-for-upstream' of git://evilpiepirate.org/~kent/linux-bcache into for-linus
Kent writes:

Jens - couple more bcache patches. Bug fixes and a doc update.
2013-05-15 10:36:25 +02:00
Kent Overstreet
f59fce847f bcache: Fix error handling in init code
This code appears to have rotted... fix various bugs and do some
refactoring.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-05-15 00:48:14 -07:00
Paul Bolle
bbb1c3b5ae bcache: drop "select CLOSURES"
The Kconfig entry for BCACHE selects CLOSURES. But there's no Kconfig
symbol CLOSURES. That symbol was used in development versions of bcache,
but was removed when the closures code was no longer provided as a
kernel library. It can safely be dropped.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
2013-05-15 00:42:51 -07:00
Emil Goode
867e116206 bcache: Fix incompatible pointer type warning
The function pointer release in struct block_device_operations
should point to functions declared as void.

Sparse warnings:

drivers/md/bcache/super.c:656:27: warning:
	incorrect type in initializer (different base types)
	drivers/md/bcache/super.c:656:27:
	expected void ( *release )( ... )
	drivers/md/bcache/super.c:656:27:
	got int ( static [toplevel] *<noident> )( ... )

drivers/md/bcache/super.c:656:2: warning:
	initialization from incompatible pointer type [enabled by default]

drivers/md/bcache/super.c:656:2: warning:
	(near initialization for ‘bcache_ops.release’) [enabled by default]

Signed-off-by: Emil Goode <emilgoode@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-05-15 00:42:50 -07:00
Joe Thornber
2f14f4b51e dm cache: set config value
Share configuration option processing code between the dm cache
ctr and message functions.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:21 +01:00
Alasdair G Kergon
2c73c471fb dm cache: move config fns
Move process_config_option() in dm-cache-target.c to make the
next patch more readable.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:21 +01:00
Joe Thornber
ac8c3f3df6 dm thin: generate event when metadata threshold passed
Generate a dm event when the amount of remaining thin pool metadata
space falls below a certain level.

The threshold is taken to be a quarter of the size of the metadata
device with a minimum threshold of 4MB.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:21 +01:00
Joe Thornber
2fc48021f4 dm persistent metadata: add space map threshold callback
Add a threshold callback to dm persistent data space maps.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:20 +01:00
Joe Thornber
7c3d3f2a87 dm persistent data: add threshold callback to space map
Add a threshold callback function to the persistent data space map
interface for a subsequent patch to use.

dm-thin and dm-cache are interested in knowing when they're getting
low on metadata or data blocks.  This patch introduces a new method
for registering a callback against a threshold.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:20 +01:00
Joe Thornber
24347e9595 dm thin: detect metadata device resizing
Allow the dm thin pool metadata device to be extended.

Whenever a pool is resumed, detect whether the size of the metadata
device has increased, and if so, extend the metadata to use the new
space.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:19 +01:00
Joe Thornber
1921c56d95 dm persistent data: support space map resizing
Support extending a dm persistent data metadata space map.

The extend itself is implemented by switching back to the boostrap
allocator and pointing to the new space.  The extra bitmap indexes are
then allocated from the new space, and finally we switch back to the
proper space map ops and tweak the reference counts.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:19 +01:00
Joe Thornber
5d0db96d13 dm thin: open dev read only when possible
If a thin pool is created in read-only-metadata mode then only open the
metadata device read-only.

Previously it was always opened with FMODE_READ | FMODE_WRITE.

(Note that dm_get_device() still allows read-only dm devices to be used
read-write at the moment: If I create a read-only linear device for the
metadata, via dmsetup load --readonly, then I can still create a rw pool
out of it.)

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:19 +01:00
Joe Thornber
b17446df2e dm thin: refactor data dev resize
Refactor device size functions in preparation for similar metadata
device resizing functions.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:18 +01:00
Joe Thornber
8c5008fac4 dm cache: replace memcpy with struct assignment
Use struct assignment rather than memcpy in dm cache.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:18 +01:00
Joe Thornber
aeed1420a3 dm cache: fix typos in comments
Fix up some typos in dm-cache comments.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:18 +01:00
Alasdair G Kergon
e12c1fd9d6 dm cache policy: fix description of lookup fn
Correct the documented requirement on the return code from dm cache policy
lookup functions stated in the policy module header file.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:17 +01:00
Joe Thornber
88a488f624 dm persistent data: fix error message typos
Fix some typos in dm-space-map-metadata.c error messages.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:17 +01:00
Joe Thornber
f8350daf7a dm cache: tune migration throttling
Tune the dm cache migration throttling.

i) Issue a tick every second, just in case there's no i/o going through.

ii) Drop the migration threshold right down to something suitable for
background work.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:16 +01:00
Mike Snitzer
042bcef889 dm mpath: enable WRITE SAME support
Enable WRITE SAME support in dm multipath.  As far as multipath is
concerned it is just another write request.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Tested-by: Bharata B Rao <bharata.rao@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:16 +01:00
Mike Snitzer
dc019b21fb dm table: fix write same support
If device_not_write_same_capable() returns true then the iterate_devices
loop in dm_table_supports_write_same() should return false.

Reported-by: Bharata B Rao <bharata.rao@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.8+
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:16 +01:00
Mikulas Patocka
502624bdad dm bufio: avoid a possible __vmalloc deadlock
This patch uses memalloc_noio_save to avoid a possible deadlock in
dm-bufio.  (it could happen only with large block size, at most
PAGE_SIZE << MAX_ORDER (typically 8MiB).

__vmalloc doesn't fully respect gfp flags. The specified gfp flags are
used for allocation of requested pages, structures vmap_area, vmap_block
and vm_struct and the radix tree nodes.

However, the kernel pagetables are allocated always with GFP_KERNEL.
Thus the allocation of pagetables can recurse back to the I/O layer and
cause a deadlock.

This patch uses the function memalloc_noio_save to set per-process
PF_MEMALLOC_NOIO flag and the function memalloc_noio_restore to restore
it. When this flag is set, all allocations in the process are done with
implied GFP_NOIO flag, thus the deadlock can't happen.

This should be backported to stable kernels, but they don't have the
PF_MEMALLOC_NOIO flag and memalloc_noio_save/memalloc_noio_restore
functions. So, PF_MEMALLOC should be set and restored instead.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:15 +01:00
Wei Yongjun
09e8b81389 dm snapshot: fix error return code in snapshot_ctr
Return -ENOMEM instead of success if unable to allocate pending
exception mempool in snapshot_ctr.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:15 +01:00
Wei Yongjun
fa4d683af3 dm cache: fix error return code in cache_create
Return -ENOMEM if memory allocation fails in cache_create
instead of 0 (to avoid NULL pointer dereference).

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:14 +01:00
Mike Snitzer
d793e68427 dm stripe: fix regression in stripe_width calculation
Fix a regression in the calculation of the stripe_width in the
dm stripe target which led to incorrect processing of device limits.

The stripe_width is the stripe device length divided by the number of
stripes.  The group of commits in the range f14fa69 ("dm stripe: fix
size test") to eb850de ("dm stripe: support for non power of 2
chunksize") interfered with each other (a merging error) and led to the
stripe_width being set incorrectly to the stripe device length divided by
chunk_size * stripe_count.

For example, a stripe device's table with: 0 33553920 striped 3 512 ...
should result in a stripe_width of 11184640 (33553920 / 3), but due to
the bug it was getting set to 21845 (33553920 / (512 * 3)).

The impact of this bug is that device topologies that previously worked
fine with the stripe target are no longer considered valid.  In
particular, there is a higher risk of seeing this issue if one of the
stripe devices has a 4K logical block size.  Resulting in an error
message like this:
"device-mapper: table: 253:4: len=21845 not aligned to h/w logical block size 4096 of dm-1"

The fix is to swap the order of the divisions and to use a temporary
variable for the second one, so that width retains the intended
value.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.6+
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10 14:37:14 +01:00
Linus Torvalds
ebb3727779 Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe:
 "It might look big in volume, but when categorized, not a lot of
  drivers are touched.  The pull request contains:

   - mtip32xx fixes from Micron.

   - A slew of drbd updates, this time in a nicer series.

   - bcache, a flash/ssd caching framework from Kent.

   - Fixes for cciss"

* 'for-3.10/drivers' of git://git.kernel.dk/linux-block: (66 commits)
  bcache: Use bd_link_disk_holder()
  bcache: Allocator cleanup/fixes
  cciss: bug fix to prevent cciss from loading in kdump crash kernel
  cciss: add cciss_allow_hpsa module parameter
  drivers/block/mg_disk.c: add CONFIG_PM_SLEEP to suspend/resume functions
  mtip32xx: Workaround for unaligned writes
  bcache: Make sure blocksize isn't smaller than device blocksize
  bcache: Fix merge_bvec_fn usage for when it modifies the bvm
  bcache: Correctly check against BIO_MAX_PAGES
  bcache: Hack around stuff that clones up to bi_max_vecs
  bcache: Set ra_pages based on backing device's ra_pages
  bcache: Take data offset from the bdev superblock.
  mtip32xx: mtip32xx: Disable TRIM support
  mtip32xx: fix a smatch warning
  bcache: Disable broken btree fuzz tester
  bcache: Fix a format string overflow
  bcache: Fix a minor memory leak on device teardown
  bcache: Documentation updates
  bcache: Use WARN_ONCE() instead of __WARN()
  bcache: Add missing #include <linux/prefetch.h>
  ...
2013-05-08 11:51:05 -07:00
Linus Torvalds
4de13d7aa8 Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block
Pull block core updates from Jens Axboe:

 - Major bit is Kents prep work for immutable bio vecs.

 - Stable candidate fix for a scheduling-while-atomic in the queue
   bypass operation.

 - Fix for the hang on exceeded rq->datalen 32-bit unsigned when merging
   discard bios.

 - Tejuns changes to convert the writeback thread pool to the generic
   workqueue mechanism.

 - Runtime PM framework, SCSI patches exists on top of these in James'
   tree.

 - A few random fixes.

* 'for-3.10/core' of git://git.kernel.dk/linux-block: (40 commits)
  relay: move remove_buf_file inside relay_close_buf
  partitions/efi.c: replace useless kzalloc's by kmalloc's
  fs/block_dev.c: fix iov_shorten() criteria in blkdev_aio_read()
  block: fix max discard sectors limit
  blkcg: fix "scheduling while atomic" in blk_queue_bypass_start
  Documentation: cfq-iosched: update documentation help for cfq tunables
  writeback: expose the bdi_wq workqueue
  writeback: replace custom worker pool implementation with unbound workqueue
  writeback: remove unused bdi_pending_list
  aoe: Fix unitialized var usage
  bio-integrity: Add explicit field for owner of bip_buf
  block: Add an explicit bio flag for bios that own their bvec
  block: Add bio_alloc_pages()
  block: Convert some code to bio_for_each_segment_all()
  block: Add bio_for_each_segment_all()
  bounce: Refactor __blk_queue_bounce to not use bi_io_vec
  raid1: use bio_copy_data()
  pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage
  pktcdvd: use bio_copy_data()
  block: Add bio_copy_data()
  ...
2013-05-08 10:13:35 -07:00
Al Viro
db2a144bed block_device_operations->release() should return void
The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-07 02:16:21 -04:00
Kent Overstreet
ee66850642 bcache: Use bd_link_disk_holder()
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-30 19:14:43 -07:00
Kent Overstreet
86b26b824c bcache: Allocator cleanup/fixes
The main fix is that bch_allocator_thread() wasn't waiting on
garbage collection to finish (if invalidate_buckets had set
ca->invalidate_needs_gc); we need that to make sure the allocator
doesn't spin and potentially block gc from finishing.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-30 19:14:40 -07:00
Shaohua Li
32f9f570d0 MD: ignore discard request for hard disks of hybid raid1/raid10 array
In SSD/hard disk hybid storage, discard request should be ignored for hard
disk. We used to be doing this way, but the unplug path forgets it.

This is suitable for stable tree since v3.6.

Cc: stable@vger.kernel.org
Reported-and-tested-by: Markus <M4rkusXXL@web.de>
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-30 14:49:36 +10:00
NeilBrown
486adf72cc md: bad block list should default to disabled.
Maintenance of a bad-block-list currently defaults to 'enabled'
and is then disabled when it cannot be supported.
This is backwards and causes problem for dm-raid which didn't know
to disable it.

So fix the defaults, and only enabled for v1.x metadata which
explicitly has bad blocks enabled.

The problem with dm-raid has been present since badblock support was
added in v3.1, so this patch is suitable for any -stable from 3.1
onwards.

Cc: stable@vger.kernel.org (3.1+)
Reported-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-30 14:49:32 +10:00
Hirokazu Takahashi
0fea7ed82b md: raid1/raid10 md devices leak memory when stopping
Hi.

Raid1 and raid10 devices leak memory every time they stop.
This is a patch for linux-3.9.0-rc7 to fix this problem.

Thanks,
Hirokazu Takahashi.

Signed-off-by: Hirokazu Takahashi <taka@valinux.co.jp>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-30 14:49:26 +10:00
Kent Overstreet
8abb2a5dba bcache: Make sure blocksize isn't smaller than device blocksize
Sanity check to make sure we don't end up doing IO the device doesn't
support.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-24 13:07:39 -07:00
Jonathan Brassow
be83651f00 DM RAID: Add message/status support for changing sync action
DM RAID:  Add message/status support for changing sync action

This patch adds a message interface to dm-raid to allow the user to more
finely control the sync actions being performed by the MD driver.  This
gives the user the ability to initiate "check" and "repair" (i.e. scrubbing).
Two additional fields have been appended to the status output to provide more
information about the type of sync action occurring and the results of those
actions, specifically: <sync_action> and <mismatch_cnt>.  These new fields
will always be populated.  This is essentially the device-mapper way of doing
what MD controls through the 'sync_action' sysfs file and shows through the
'mismatch_cnt' sysfs file.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:43 +10:00
Jonathan Brassow
a91d5ac048 MD: Export 'md_reap_sync_thread' function
MD: Export 'md_reap_sync_thread' function

Make 'md_reap_sync_thread' available to other files, specifically dm-raid.c.
- rename reap_sync_thread to md_reap_sync_thread
- move the fn after md_check_recovery to match md.h declaration placement
- export md_reap_sync_thread

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:43 +10:00
NeilBrown
b6d428c669 md: don't update metadata when stopping a read-only array.
read-only arrays should stay that way as much as possible.
Updating the metadata - which could be triggered by a re-add
while assembling the array metadata - should be avoided.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:42 +10:00
NeilBrown
7ceb17e87b md: Allow devices to be re-added to a read-only array.
When assembling an array incrementally we might want to make
it device available when "enough" devices are present, but maybe
not "all" devices are present.
If the remaining devices appear before the array is actually used,
they should be added transparently.

We do this by using the "read-auto" mode where the array acts like
it is read-only until a write request arrives.

Current an add-device request switches a read-auto array to active.
This means that only one device can be added after the array is first
made read-auto.  This isn't a problem for RAID5, but is not ideal for
RAID6 or RAID10.
Also we don't really want to switch the array to read-auto at all
when re-adding a device as this doesn't really imply any change.

So:
 - remove the "md_update_sb()" call from add_new_disk().  This isn't
   really needed as just adding a disk doesn't require a metadata
   update.  Instead, just set MD_CHANGE_DEVS.  This will effect a
   metadata update soon enough, once the array is not read-only.

 - Allow the ADD_NEW_DISK ioctl to succeed without activating a
   read-auto array, providing the MD_DISK_SYNC flag is set.
   In this case, the device will be rejected if it cannot be added
   with the correct device number, or has an incorrect event count.

 - Teach remove_and_add_spares() to be careful about adding spares
   when the array is read-only (or read-mostly) - only add devices
   that are thought to be in-sync, and only do it if the array is
   in-sync itself.

 - In md_check_recovery, use remove_and_add_spares in the read-only
   case, rather than open coding just the 'remove' part of it.

Reported-by: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:42 +10:00
Martin Wilck
7e83ccbecd md/raid10: Allow skipping recovery when clean arrays are assembled
When an array is assembled incrementally with mdadm -I -R
and the array switches to "active" mode, md starts a recovery.

If the array was clean, the "fullsync" flag will be 0. Skip
the full recovery in this case, as RAID1 does (the code was
actually copied from the sync_request() method of RAID1).

Signed-off-by: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:42 +10:00
NeilBrown
c0b32972fb md/raid5: avoid an extra write when writing to a known-bad-block.
If we write to a known-bad-block it will be flags as having
a ReadError by analyse_stripe, but the write will proceed anyway
(as it should).  Then the read-error handling will kick in an
write again, then re-read.

We don't need that 'write-again', so set R5_ReWrite so it looks like
it has already been done.  Then we will just get the re-read, which we
want.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:42 +10:00
majianpeng
6f608040ce md/raid5: Change or of some order to improve efficiency.
As the function call is the most expensive of these tests it should be
done later in the chain so that it can be avoided in some cases.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:41 +10:00
Akinobu Mita
3f810b6c4a md: use set_bit_le and clear_bit_le
The value returned by test_and_set_bit_le() drivers/md/bitmap.c is not used.
So just use set_bit_le(). The same goes for test_and_clear_bit_le().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:41 +10:00
NeilBrown
3ea8929da3 md: HOT_DISK_REMOVE shouldn't make a read-auto device active.
If a fail device or a spare is removed from an array, there is
not need to make the array 'active'.  If/when the array does become
active for some other reason the metadata will be update to reflect
the removal.
If that never happens and the array is stopped while still read-auto,
then there is no loss in forgetting the that the device had 'failed'.

A read-only array will leave failed devices attached to
the array personality, so we need to explicitly call
remove_and_add_spares() to free it (clearing Blocked just
like we do in store_slot()).

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:41 +10:00
NeilBrown
746d3207ae md: use common code for all calls to ->hot_remove_disk()
slot_store and remove_and_add_spares both call ->hot_remove_disk(),
but with slightly different tests and consequences, which is
at least untidy and might be buggy.

So modify remove_and_add_spaces() so that it can be asked
to remove a specific device, and call it from slot_store().

We also clear the Blocked flag to ensure that doesn't prevent
removal.  The purpose of Blocked is to prevent automatic removal
by the kernel before an error is acknowledged.
If the array is read/write then user-space would have not reason
to remove a device unless it was known to be 'spare' or 'faulty' in
which it would have already cleared the Blocked flag.
If the array is read-only, the flag might still be blocked, but
there is no harm in clearing the flag for read-only arrays.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:41 +10:00
NeilBrown
d87f064f58 md: never update metadata when array is read-only.
Normally we don't even try to update the metadata if
the array is read-only.  However future patches
will increase the number of things that can happen on a read-only
array, so it is safest to explicitly disable this.

Every time that mddev->ro is set to 0, either
 - md_update_sb will be called again (at least if MD_CHANGE_DEVS
   is set) or
 - the mddev->thread is scheduled, which will also run
   md_update_sb if needed.

So this is safe: if the array ever become read-write the
metadata will be updated.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-04-24 11:42:40 +10:00
Kent Overstreet
a09ded8edf bcache: Fix merge_bvec_fn usage for when it modifies the bvm
Stacked md devices reuse the bvm for the subordinate device, causing
problems...

Reported-by: Michael Balser <michael.balser@profitbricks.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-22 14:44:24 -07:00
Kent Overstreet
1545f13730 bcache: Correctly check against BIO_MAX_PAGES
bch_bio_max_sectors() was checking against BIO_MAX_PAGES as if the limit
was for the total bytes in the bio, not the number of segments.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-20 17:57:42 -07:00
Kent Overstreet
bca97adaf5 bcache: Hack around stuff that clones up to bi_max_vecs
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-20 17:57:41 -07:00
Kent Overstreet
4f0fd955cd bcache: Set ra_pages based on backing device's ra_pages
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-20 17:57:26 -07:00
Kent Overstreet
2903381fce bcache: Take data offset from the bdev superblock.
Add a new superblock version, and consolidate related defines.

Signed-off-by: Gabriel de Perthuis <g2p.code+bcache@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-20 17:56:12 -07:00
Linus Torvalds
0a82a8d132 Revert "block: add missing block_bio_complete() tracepoint"
This reverts commit 3a366e614d.

Wanlong Gao reports that it causes a kernel panic on his machine several
minutes after boot. Reverting it removes the panic.

Jens says:
 "It's not quite clear why that is yet, so I think we should just revert
  the commit for 3.9 final (which I'm assuming is pretty close).

  The wifi is crap at the LSF hotel, so sending this email instead of
  queueing up a revert and pull request."

Reported-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Requested-by: Jens Axboe <axboe@kernel.dk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-18 09:00:26 -07:00
Kent Overstreet
cef5279735 bcache: Disable broken btree fuzz tester
Reported-by: <sasha.levin@oracle.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-08 13:33:49 -07:00
Kent Overstreet
91bbcfc361 bcache: Fix a format string overflow
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-08 13:33:49 -07:00
Kent Overstreet
8ef747909c bcache: Fix a minor memory leak on device teardown
Reported-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-08 13:33:48 -07:00
Kent Overstreet
cc0f4eaa61 bcache: Use WARN_ONCE() instead of __WARN()
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-08 13:33:48 -07:00
Geert Uytterhoeven
cd953ed036 bcache: Add missing #include <linux/prefetch.h>
m68k/allmodconfig:

drivers/md/bcache/bset.c: In function ‘bset_search_tree’:
drivers/md/bcache/bset.c:727: error: implicit declaration of function ‘prefetch’

drivers/md/bcache/btree.c: In function ‘bch_btree_node_get’:
drivers/md/bcache/btree.c:933: error: implicit declaration of function ‘prefetch’

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-08 13:33:48 -07:00
Kent Overstreet
c19ed23a0b bcache: Sparse fixes
Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-04-08 13:33:48 -07:00
Mike Snitzer
19b0092e26 dm cache: reduce bio front_pad size in writeback mode
A recent patch to fix the dm cache target's writethrough mode extended
the bio's front_pad to include a 1056-byte struct dm_bio_details.
Writeback mode doesn't need this, so this patch reduces the
per_bio_data_size to 16 bytes in this case instead of 1096.

The dm_bio_details structure was added in "dm cache: fix writes to
cache device in writethrough mode" which fixed commit e2e74d617e ("dm
cache: fix race in writethrough implementation").  In writeback mode
we avoid allocating the writethrough-specific members of the
per_bio_data structure (the dm_bio_details structure included).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-04-05 15:36:34 +01:00
Darrick J. Wong
b844fe6918 dm cache: fix writes to cache device in writethrough mode
The dm-cache writethrough strategy introduced by commit e2e74d617e
("dm cache: fix race in writethrough implementation") issues a bio to
the origin device, remaps and then issues the bio to the cache device.
This more conservative in-series approach was selected to favor
correctness over performance (of the previous parallel writethrough).
However, this in-series implementation that reuses the same bio to write
both the origin and cache device didn't take into account that the block
layer's req_bio_endio() modifies a completing bio's bi_sector and
bi_size.  So the new writethrough strategy needs to preserve these bio
fields, and restore them before submission to the cache device,
otherwise nothing gets written to the cache (because bi_size is 0).

This patch adds a struct dm_bio_details field to struct per_bio_data,
and uses dm_bio_record() and dm_bio_restore() to ensure the bio is
restored before reissuing to the cache device.  Adding such a large
structure to the per_bio_data is not ideal but we can improve this
later, for now correctness is the important thing.

This problem initially went unnoticed because the dm-cache test-suite
uses a linear DM device for the dm-cache device's origin device.
Writethrough worked as expected because DM submits a *clone* of the
original bio, so the original bio which was reused for the cache was
never touched.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-04-05 15:36:32 +01:00
Jens Axboe
64f8de4da7 Merge branch 'writeback-workqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq into for-3.10/core
Tejun writes:

-----

This is the pull request for the earlier patchset[1] with the same
name.  It's only three patches (the first one was committed to
workqueue tree) but the merge strategy is a bit involved due to the
dependencies.

* Because the conversion needs features from wq/for-3.10,
  block/for-3.10/core is based on rc3, and wq/for-3.10 has conflicts
  with rc3, I pulled mainline (rc5) into wq/for-3.10 to prevent those
  workqueue conflicts from flaring up in block tree.

* Resolving the issue that Jan and Dave raised about debugging
  requires arch-wide changes.  The patchset is being worked on[2] but
  it'll have to go through -mm after these changes show up in -next,
  and not included in this pull request.

The three commits are located in the following git branch.

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git writeback-workqueue

Pulling it into block/for-3.10/core produces a conflict in
drivers/md/raid5.c between the following two commits.

  e3620a3ad5 ("MD RAID5: Avoid accessing gendisk or queue structs when not available")
  2f6db2a707 ("raid5: use bio_reset()")

The conflict is trivial - one removes an "if ()" conditional while the
other removes "rbi->bi_next = NULL" right above it.  We just need to
remove both.  The merged branch is available at

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git block-test-merge

so that you can use it for verification.  The test merge commit has
proper merge description.

While these changes are a bit of pain to route, they make code simpler
and even have, while minute, measureable performance gain[3] even on a
workload which isn't particularly favorable to showing the benefits of
this conversion.

----

Fixed up the conflict.

Conflicts:
	drivers/md/raid5.c

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-04-02 10:04:39 +02:00
Kent Overstreet
169ef1cf61 bcache: Don't export utility code, prefix with bch_
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-28 12:50:55 -06:00
Kent Overstreet
29177b8966 bcache: Fix for the build fixes
Commit 82a84eaf7e51ba3da0c36cbc401034a4e943492d left a return 0 in
closure_debug_init(). Whoops.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-25 19:36:39 -06:00
Kent Overstreet
b1a67b0f4c bcache: Style/checkpatch fixes
Took out some nested functions, and fixed some more checkpatch
complaints.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-25 13:06:13 -06:00
Kent Overstreet
07e86ccb54 bcache: Build fixes from test robot
config: make ARCH=i386 allmodconfig

All error/warnings:

   drivers/md/bcache/bset.c: In function 'bch_ptr_bad':
>> drivers/md/bcache/bset.c:164:2: warning: format '%li' expects argument of type 'long int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/debug.c: In function 'bch_pbtree':
>> drivers/md/bcache/debug.c:86:4: warning: format '%li' expects argument of type 'long int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/btree.c: In function 'bch_btree_read_done':
>> drivers/md/bcache/btree.c:245:8: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/closure.o: In function `closure_debug_init':
>> (.init.text+0x0): multiple definition of `init_module'
>> drivers/md/bcache/super.o:super.c:(.init.text+0x0): first defined here

Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-25 13:06:13 -06:00
Kent Overstreet
cafe563591 bcache: A block layer cache
Does writethrough and writeback caching, handles unclean shutdown, and
has a bunch of other nifty features motivated by real world usage.

See the wiki at http://bcache.evilpiepirate.org for more.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
2013-03-23 16:11:31 -07:00
Linus Torvalds
22c3f2fff6 A few bugfixes for md
- recent regressions in raid5
  - recent regressions in dmraid
  - a few instances of CONFIG_MULTICORE_RAID456 linger
 
 Several tagged for -stable
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Merge tag 'md-3.9-fixes' of git://neil.brown.name/md

Pull md fixes from NeilBrown:
 "A few bugfixes for md

   - recent regressions in raid5
   - recent regressions in dmraid
   - a few instances of CONFIG_MULTICORE_RAID456 linger

  Several tagged for -stable"

* tag 'md-3.9-fixes' of git://neil.brown.name/md:
  md: remove CONFIG_MULTICORE_RAID456 entirely
  md/raid5: ensure sync and DISCARD don't happen at the same time.
  MD: Prevent sysfs operations on uninitialized kobjects
  MD RAID5: Avoid accessing gendisk or queue structs when not available
  md/raid5: schedule_construction should abort if nothing to do.
2013-03-23 15:49:49 -07:00
Kent Overstreet
a07876064a block: Add bio_alloc_pages()
More utility code to replace stuff that's getting open coded.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
2013-03-23 14:26:31 -07:00
Kent Overstreet
cb34e057ad block: Convert some code to bio_for_each_segment_all()
More prep work for immutable bvecs:

A few places in the code were either open coding or using the wrong
version - fix.

After we introduce the bvec iter, it'll no longer be possible to modify
the biovec through bio_for_each_segment_all() - it doesn't increment a
pointer to the current bvec, you pass in a struct bio_vec (not a
pointer) which is updated with what the current biovec would be (taking
into account bi_bvec_done and bi_size).

So because of that it's more worthwhile to be consistent about
bio_for_each_segment()/bio_for_each_segment_all() usage.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
CC: Alasdair Kergon <agk@redhat.com>
CC: dm-devel@redhat.com
CC: Alexander Viro <viro@zeniv.linux.org.uk>
2013-03-23 14:26:30 -07:00
Kent Overstreet
d74c6d514f block: Add bio_for_each_segment_all()
__bio_for_each_segment() iterates bvecs from the specified index
instead of bio->bv_idx.  Currently, the only usage is to walk all the
bvecs after the bio has been advanced by specifying 0 index.

For immutable bvecs, we need to split these apart;
bio_for_each_segment() is going to have a different implementation.
This will also help document the intent of code that's using it -
bio_for_each_segment_all() is only legal to use for code that owns the
bio.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Neil Brown <neilb@suse.de>
CC: Boaz Harrosh <bharrosh@panasas.com>
2013-03-23 14:26:28 -07:00
Kent Overstreet
d3b45c2a05 raid1: use bio_copy_data()
This doesn't really delete any code _yet_, but once immutable bvecs are
done we can just delete the rest of the code in that loop.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
2013-03-23 14:15:38 -07:00
Kent Overstreet
b783863f68 raid1: Refactor narrow_write_error() to not use bi_idx
More bi_idx removal. This code was just open coding bio_clone(). This
could probably be further improved by using bio_advance() instead of
skipping over null pages, but that'd be a larger rework.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
2013-03-23 14:15:36 -07:00
Kent Overstreet
2f6db2a707 raid5: use bio_reset()
Had to shuffle the code around a bit (where bi_rw and bi_end_io were
set), but shouldn't really be anything tricky here

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
2013-03-23 14:15:35 -07:00
Kent Overstreet
2aabaa65ad raid1: use bio_reset()
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
2013-03-23 14:15:34 -07:00
Kent Overstreet
8be185f2c9 raid10: Use bio_reset()
More prep work for immutable bio vecs, mainly getting rid of references
to bi_idx.

bio_reset was being open coded in a few places. The one in sync_request
was a bit nontrivial to convert, so could use some extra eyeballs.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
Acked-by: NeilBrown <neilb@suse.de>
2013-03-23 14:15:33 -07:00
Kent Overstreet
9e882242c6 block: Add submit_bio_wait(), remove from md
Random cleanup - this code was duplicated and it's not really specific
to md.

Also added the ability to return the actual error code.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
2013-03-23 14:15:32 -07:00
Kent Overstreet
4f2ac93c17 block: Remove bi_idx references
For immutable bvecs, all bi_idx usage needs to be audited - so here
we're removing all the unnecessary uses.

Most of these are places where it was being initialized on a bio that
was just allocated, a few others are conversions to standard macros.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
2013-03-23 14:15:31 -07:00
Kent Overstreet
5b83636ae3 block: Change bio_split() to respect the current value of bi_idx
In the current code bio_split() won't be seeing partially completed bios
so this doesn't change any behaviour, but this makes the code a bit
clearer as to what bio_split() actually requires.

The immediate purpose of the patch is removing unnecessary bi_idx
references, but the end goal is to allow partial completed bios to be
submitted, which along with immutable biovecs enables effecient bio
splitting.

Some of the callers were (double) checking that bios could be split, so
update their checks too.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Lars Ellenberg <drbd-dev@lists.linbit.com>
CC: Neil Brown <neilb@suse.de>
CC: Martin K. Petersen <martin.petersen@oracle.com>
2013-03-23 14:15:30 -07:00
Kent Overstreet
aa8b57aa3d block: Use bio_sectors() more consistently
Bunch of places in the code weren't using it where they could be -
this'll reduce the size of the patch that puts bi_sector/bi_size/bi_idx
into a struct bvec_iter.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: "Ed L. Cashin" <ecashin@coraid.com>
CC: Nick Piggin <npiggin@kernel.dk>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Jim Paris <jim@jtan.com>
CC: Geoff Levand <geoff@infradead.org>
CC: Alasdair Kergon <agk@redhat.com>
CC: dm-devel@redhat.com
CC: Neil Brown <neilb@suse.de>
CC: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Ed Cashin <ecashin@coraid.com>
2013-03-23 14:15:30 -07:00
Kent Overstreet
f73a1c7d11 block: Add bio_end_sector()
Just a little convenience macro - main reason to add it now is preparing
for immutable bio vecs, it'll reduce the size of the patch that puts
bi_sector/bi_size/bi_idx into a struct bvec_iter.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Lars Ellenberg <drbd-dev@lists.linbit.com>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Alasdair Kergon <agk@redhat.com>
CC: dm-devel@redhat.com
CC: Neil Brown <neilb@suse.de>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: Heiko Carstens <heiko.carstens@de.ibm.com>
CC: linux-s390@vger.kernel.org
CC: Chris Mason <chris.mason@fusionio.com>
CC: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
2013-03-23 14:15:29 -07:00
Kent Overstreet
fb9e353476 md: Convert md_trim_bio() to use bio_advance()
Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
Acked-by: NeilBrown <neilb@suse.de>
2013-03-23 14:15:28 -07:00
Mike Snitzer
ea2dd8c1ed dm cache: policy ignore hints if generated by different version
When reading the dm cache metadata from disk, ignore the policy hints
unless they were generated by the same major version number of the same
policy module.

The hints are considered to be private data belonging to the specific
module that generated them and there is no requirement for them to make
sense to different versions of the policy that generated them.
Policy modules are all required to work fine if no previous hints are
supplied (or if existing hints are lost).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:28 +00:00
Mike Snitzer
4e7f506f64 dm cache: policy change version from string to integer set
Separate dm cache policy version string into 3 unsigned numbers
corresponding to major, minor and patchlevel and store them at the end
of the on-disk metadata so we know which version of the policy generated
the hints in case a future version wants to use them differently.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:27 +00:00
Joe Thornber
e2e74d617e dm cache: fix race in writethrough implementation
We have found a race in the optimisation used in the dm cache
writethrough implementation.  Currently, dm core sends the cache target
two bios, one for the origin device and one for the cache device and
these are processed in parallel.  This patch avoids the race by
changing the code back to a simpler (slower) implementation which
processes the two writes in series, one after the other, until we can
develop a complete fix for the problem.

When the cache is in writethrough mode it needs to send WRITE bios to
both the origin and cache devices.

Previously we've been implementing this by having dm core query the
cache target on every write to find out how many copies of the bio it
wants.  The cache will ask for two bios if the block is in the cache,
and one otherwise.

Then main problem with this is it's racey.  At the time this check is
made the bio hasn't yet been submitted and so isn't being taken into
account when quiescing a block for migration (promotion or demotion).
This means a single bio may be submitted when two were needed because
the block has since been promoted to the cache (catastrophic), or two
bios where only one is needed (harmless).

I really don't want to start entering bios into the quiescing system
(deferred_set) in the get_num_write_bios callback.  Instead this patch
simplifies things; only one bio is submitted by the core, this is
first written to the origin and then the cache device in series.
Obviously this will have a latency impact.

deferred_writethrough_bios is introduced to record bios that must be
later issued to the cache device from the worker thread.  This deferred
submission, after the origin bio completes, is required given that we're
in interrupt context (writethrough_endio).

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:27 +00:00
Joe Thornber
79ed9caffc dm cache: metadata clear dirty bits on clean shutdown
When writing the dirty bitset to the metadata device on a clean
shutdown, clear the dirty bits.  Previously they were left indicating
the cache was dirty. This led to confusion about whether there really
was dirty data in the cache or not.  (This was a harmless bug.)

Reported-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:27 +00:00
Heinz Mauelshagen
b978440b8d dm cache: avoid calling policy destructor twice on error
If the cache policy's config values are not able to be set we must
set the policy to NULL after destroying it in create_cache_policy()
so we don't attempt to destroy it a second time later.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:26 +00:00
Heinz Mauelshagen
617a0b89da dm cache: detect cache_create failure
Return error if cache_create() fails.

A missing return check made cache_ctr continue even after an error in
cache_create() resulting in the cache object being destroyed.  So a
simple failure like an odd number of cache policy config value arguments
would result in an oops.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:26 +00:00
Joe Thornber
414dd67d50 dm cache: avoid 64 bit division on 32 bit
Squash various 32bit link errors.

  >> on i386:
  >> drivers/built-in.o: In function `is_discarded_oblock':
  >> dm-cache-target.c:(.text+0x1ea28e): undefined reference to `__udivdi3'
  ...

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:25 +00:00
Mikulas Patocka
3b6b7813b1 dm verity: avoid deadlock
A deadlock was found in the prefetch code in the dm verity map
function.  This patch fixes this by transferring the prefetch
to a worker thread and skipping it completely if kmalloc fails.

If generic_make_request is called recursively, it queues the I/O
request on the current->bio_list without making the I/O request
and returns. The routine making the recursive call cannot wait
for the I/O to complete.

The deadlock occurs when one thread grabs the bufio_client
mutex and waits for an I/O to complete but the I/O is queued
on another thread's current->bio_list and is waiting to get
the mutex held by the first thread.

The fix recognises that prefetching is not essential.  If memory
can be allocated, it queues the prefetch request to the worker thread,
but if not, it does nothing.

Signed-off-by: Paul Taysom <taysom@chromium.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
2013-03-20 17:21:25 +00:00
Joe Thornber
58051b94e0 dm thin: fix non power of two discard granularity calc
Fix a discard granularity calculation to work for non power of 2 block sizes.

In order for thinp to passdown discard bios to the underlying data
device, the data device must have a discard granularity that is a
factor of the thinp block size.  Originally this check was done by
using bitops since the block_size was known to be a power of two.

Introduced by commit f13945d757
("dm thin: support a non power of 2 discard_granularity").

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:25 +00:00
Joe Thornber
f046f89a99 dm thin: fix discard corruption
Fix a bug in dm_btree_remove that could leave leaf values with incorrect
reference counts.  The effect of this was that removal of a shared block
could result in the space maps thinking the block was no longer used.
More concretely, if you have a thin device and a snapshot of it, sending
a discard to a shared region of the thin could corrupt the snapshot.

Thinp uses a 2-level nested btree to store it's mappings.  This first
level is indexed by thin device, and the second level by logical
block.

Often when we're removing an entry in this mapping tree we need to
rebalance nodes, which can involve shadowing them, possibly creating a
copy if the block is shared.  If we do create a copy then children of
that node need to have their reference counts incremented.  In this
way reference counts percolate down the tree as shared trees diverge.

The rebalance functions were incrementing the children at the
appropriate time, but they were always assuming the children were
internal nodes.  This meant the leaf values (in our case packed
block/flags entries) were not being incremented.

Cc: stable@vger.kernel.org
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20 17:21:24 +00:00
Paul Bolle
238f5908bd md: remove CONFIG_MULTICORE_RAID456 entirely
Once instance of this Kconfig macro remained after commit
51acbcec6c ("md: remove
CONFIG_MULTICORE_RAID456"). Remove that one too. And, while we're at it,
also remove it from the defconfig files that carry it.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 13:21:14 +11:00
NeilBrown
f8dfcffd04 md/raid5: ensure sync and DISCARD don't happen at the same time.
A number of problems can occur due to races between
resync/recovery and discard.

- if sync_request calls handle_stripe() while a discard is
  happening on the stripe, it might call handle_stripe_clean_event
  before all of the individual discard requests have completed
  (so some devices are still locked, but not all).
  Since commit ca64cae960
     md/raid5: Make sure we clear R5_Discard when discard is finished.
  this will cause R5_Discard to be cleared for the parity device,
  so handle_stripe_clean_event() will not be called when the other
  devices do become unlocked, so their ->written will not be cleared.
  This ultimately leads to a WARN_ON in init_stripe and a lock-up.

- If handle_stripe_clean_event() does clear R5_UPTODATE at an awkward
  time for resync, it can lead to s->uptodate being less than disks
  in handle_parity_checks5(), which triggers a BUG (because it is
  one).

So:
 - keep R5_Discard on the parity device until all other devices have
   completed their discard request
 - make sure we don't try to have a 'discard' and a 'sync' action at
   the same time.
   This involves a new stripe flag to we know when a 'discard' is
   happening, and the use of R5_Overlap on the parity disk so when a
   discard is wanted while a sync is active, so we know to wake up
   the discard at the appropriate time.

Discard support for RAID5 was added in 3.7, so this is suitable for
any -stable kernel since 3.7.

Cc: stable@vger.kernel.org (v3.7+)
Reported-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Tested-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 13:20:59 +11:00
Jonathan Brassow
90584fc93d MD: Prevent sysfs operations on uninitialized kobjects
MD: Prevent sysfs operations on uninitialized kobjects

Device-mapper does not use sysfs; but when device-mapper is leveraging
MD's RAID personalities, MD sometimes attempts to update sysfs.  This
patch adds checks for 'mddev-kobj.sd' in sysfs_[un]link_rdev to ensure
it is about to operate on something valid.  This patch also checks for
'mddev->kobj.sd' before calling 'sysfs_notify' in 'remove_and_add_spares'.
Although 'sysfs_notify' already makes this check, doing so in
'remove_and_add_spares' prevents an additional mutex operation.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 13:17:57 +11:00
Jonathan Brassow
e3620a3ad5 MD RAID5: Avoid accessing gendisk or queue structs when not available
MD RAID5:  Fix kernel oops when RAID4/5/6 is used via device-mapper

Commit a9add5d (v3.8-rc1) added blktrace calls to the RAID4/5/6 driver.
However, when device-mapper is used to create RAID4/5/6 arrays, the
mddev->gendisk and mddev->queue fields are not setup.  Therefore, calling
things like trace_block_bio_remap will cause a kernel oops.  This patch
conditionalizes those calls on whether the proper fields exist to make
the calls.  (Device-mapper will call trace_block_bio_remap on its own.)

This patch is suitable for the 3.8.y stable kernel.

Cc: stable@vger.kernel.org (v3.8+)
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 13:16:57 +11:00
NeilBrown
ce7d363aaf md/raid5: schedule_construction should abort if nothing to do.
Since commit 1ed850f356
    md/raid5: make sure to_read and to_write never go negative.

It has been possible for handle_stripe_dirtying to be called
when there isn't actually any work to do.
It then calls schedule_reconstruction() which will set R5_LOCKED
on the parity block(s) even when nothing else is happening.
This then causes problems in do_release_stripe().

So add checks to schedule_reconstruction() so that if it doesn't
find anything to do, it just aborts.

This bug was introduced in v3.7, so the patch is suitable
for -stable kernels since then.

Cc: stable@vger.kernel.org (v3.7+)
Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-03-20 12:16:51 +11:00
Linus Torvalds
a5e0d73163 md updates for 3.9
mostly little bugfixes.
 Only "feature" is a new RAID10 layout which slightly
 improves the number of sets of devices that can concurrently
 fail, without data loss.
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Merge tag 'md-3.9' of git://neil.brown.name/md

Pull md updates from NeilBrown:
 "Mostly little bugfixes.

  Only "feature" is a new RAID10 layout which slightly improves the
  number of sets of devices that can concurrently fail, without data
  loss."

* tag 'md-3.9' of git://neil.brown.name/md:
  md: expedite metadata update when switching  read-auto -> active
  md: remove CONFIG_MULTICORE_RAID456
  md/raid1,raid10: fix deadlock with freeze_array()
  md/raid0: improve error message when converting RAID4-with-spares to RAID0
  md: raid0: fix error return from create_stripe_zones.
  md: fix two bugs when attempting to resize RAID0 array.
  DM RAID: Add support for MD's RAID10 "far" and "offset" algorithms
  MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 2)
  MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1)
  MD RAID10: Minor non-functional code changes
  md: raid1,10: Handle REQ_WRITE_SAME flag in write bios
  md: protect against crash upon fsync on ro array
2013-03-05 17:22:08 -08:00
Heinz Mauelshagen
8735a81347 dm cache: add cleaner policy
A simple cache policy that writes back all data to the origin.

This is used to decommission a dm cache by emptying it.

Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:52 +00:00
Joe Thornber
f283635281 dm cache: add mq policy
A cache policy that uses a multiqueue ordered by recent hit
count to select which blocks should be promoted and demoted.
This is meant to be a general purpose policy.  It prioritises
reads over writes.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber
c6b4fcbad0 dm: add cache target
Add a target that allows a fast device such as an SSD to be used as a
cache for a slower device such as a disk.

A plug-in architecture was chosen so that the decisions about which data
to migrate and when are delegated to interchangeable tunable policy
modules.  The first general purpose module we have developed, called
"mq" (multiqueue), follows in the next patch.  Other modules are
under development.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Heinz Mauelshagen <mauelshagen@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber
7a87edfee7 dm persistent data: add bitset
Add a persistent bitset as a wrapper around dm-array.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber
6513c29f44 dm persistent data: add transactional array
Add a transactional array.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:51 +00:00
Joe Thornber
025b96853f dm thin: remove cells from stack
This patch takes advantage of the new bio-prison interface where the
memory is now passed in rather than using a mempool in bio-prison.
This allows the map function to avoid performing potentially-blocking
allocations that could lead to deadlocks: We want to avoid the cell
allocation that is done in bio_detain.

(The potential for mempool deadlocks still remains in other functions
that use bio_detain.)

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:50 +00:00
Joe Thornber
6beca5eb6e dm bio prison: pass cell memory in
Change the dm_bio_prison interface so that instead of allocating memory
internally, dm_bio_detain is supplied with a pre-allocated cell each
time it is called.

This enables a subsequent patch to move the allocation of the struct
dm_bio_prison_cell outside the thin target's mapping function so it can
no longer block there.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:50 +00:00
Joe Thornber
4e7f1f9089 dm persistent data: add btree_walk
Add dm_btree_walk to iterate through the contents of a btree.
This will be used by the dm cache target.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:50 +00:00
Alasdair G Kergon
b0d8ed4d96 dm: add target num_write_bios fn
Add a num_write_bios function to struct target.

If an instance of a target sets this, it will be queried before the
target's mapping function is called on a write bio, and the response
controls the number of copies of the write bio that the target will
receive.

This provides a convenient way for a target to send the same data to
more than one device.  The new cache target uses this in writethrough
mode, to send the data both to the cache and the backing device.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:49 +00:00
Mikulas Patocka
df5d2e9089 dm kcopyd: introduce configurable throttling
This patch allows the administrator to reduce the rate at which kcopyd
issues I/O.

Each module that uses kcopyd acquires a throttle parameter that can be
set in /sys/module/*/parameters.

We maintain a history of kcopyd usage by each module in the variables
io_period and total_period in struct dm_kcopyd_throttle. The actual
kcopyd activity is calculated as a percentage of time equal to
"(100 * io_period / total_period)".  This is compared with the user-defined
throttle percentage threshold and if it is exceeded, we sleep.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:49 +00:00
Mikulas Patocka
a26062416e dm ioctl: allow message to return data
This patch introduces enhanced message support that allows the
device-mapper core to recognise messages that are common to all devices,
and for messages to return data to userspace.

Core messages are processed by the function "message_for_md".  If the
device mapper doesn't support the message, it is passed to the target
driver.

If the message returns data, the kernel sets the flag
DM_MESSAGE_OUT_FLAG.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:49 +00:00
Mikulas Patocka
02cde50b7e dm ioctl: optimize functions without variable params
Device-mapper ioctls receive and send data in a buffer supplied
by userspace.  The buffer has two parts.  The first part contains
a 'struct dm_ioctl' and has a fixed size.  The second part depends
on the ioctl and has a variable size.

This patch recognises the specific ioctls that do not use the variable
part of the buffer and skips allocating memory for it.

In particular, when a device is suspended and a resume ioctl is sent,
this now avoid memory allocation completely.

The variable "struct dm_ioctl tmp" is moved from the function
copy_params to its caller ctl_ioctl and renamed to param_kernel.
It is used directly when the ioctl function doesn't need any arguments.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:49 +00:00
Mikulas Patocka
e2914cc26b dm ioctl: introduce ioctl_flags
This patch introduces flags for each ioctl function.

So far, one flag is defined, IOCTL_FLAGS_NO_PARAMS.  It is set if the
function processing the ioctl doesn't take or produce any parameters in
the section of the data buffer that has a variable size.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:48 +00:00
Jun'ichi Nomura
5f01520415 dm: merge io_pool and tio_pool
This patch merges io_pool and tio_pool into io_pool and cleans up
related functions.

Though device-mapper used to have 2 pools of objects for each dm device,
the use of bioset frontbad for per-bio data has shrunk the number of
pools to 1 for both bio-based and request-based device types.
(See c0820cf5 "dm: introduce per_bio_data" and
 94818742 "dm: Use bioset's front_pad for dm_rq_clone_bio_info")

So dm no longer has to maintain 2 different pointers.

No functional changes.

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:48 +00:00
Jun'ichi Nomura
23e5083b4d dm: remove unused _rq_bio_info_cache
Remove _rq_bio_info_cache, which is no longer used.
No functional changes.

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:48 +00:00
Mike Christie
87eb5b21d9 dm: fix limits initialization when there are no data devices
dm_calculate_queue_limits will first reset the provided limits to
defaults using blk_set_stacking_limits; whereby defeating the purpose of
retaining the original live table's limits -- as was intended via commit
3ae7065616 ("dm: retain table limits when
swapping to new table with no devices").

Fix this improper limits initialization (in the no data devices case) by
avoiding the call to dm_calculate_queue_limits.

[patch header revised by Mike Snitzer]

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.6+
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:48 +00:00
Mikulas Patocka
23cb21092e dm snapshot: add missing module aliases
Add module aliases so that autoloading works correctly if the user
tries to activate "snapshot-origin" or "snapshot-merge" targets.

Reference: https://bugzilla.redhat.com/889973

Reported-by: Chao Yang <chyang@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:47 +00:00
Mike Snitzer
018cede93c dm persistent data: set some btree fn parms const
Mark some constant parameters constant in some dm-btree functions.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:47 +00:00
Alasdair G Kergon
e4c938111f dm: refactor bio cloning
Refactor part of the bio splitting and cloning code to try to make it
easier to understand.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:47 +00:00
Alasdair G Kergon
14fe594d67 dm: rename bio cloning functions
Rename functions involved in splitting and cloning bios.

The sequence of functions is now:
  (1) __split_and_process* - entry point that selects the processing strategy
  (2) __send* - prepare the details for each bio needed and loop through them
  (3) __clone_and_map* - creates a clone and maps it

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:47 +00:00
Alasdair G Kergon
55a62eef8d dm: rename request variables to bios
Use 'bio' in the name of variables and functions that deal with
bios rather than 'request' to avoid confusion with the normal
block layer use of 'request'.

No functional changes.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:47 +00:00
Alasdair G Kergon
bd2a49b86d dm: clean up clone_bio
Remove the no-longer-used struct bio_set argument from clone_bio and split_bvec.
Use tio->ti in __map_bio() instead of passing in ti.
Factor out some code for setting up cloned bios.
Take target_request_nr as a parameter to alloc_tio().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:46 +00:00
Kees Cook
88ae4c5294 dm persistent data: remove CONFIG_EXPERIMENTAL
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:46 +00:00
Alasdair G Kergon
d57916a00f dm: remove CONFIG_EXPERIMENTAL
Remove EXPERIMENTAL from all existing device-mapper targets.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:46 +00:00
Mike Snitzer
58f77a2196 dm thin: use block_size_is_power_of_two
Use block_size_is_power_of_two() rather than checking
sectors_per_block_shift directly.  Also introduce local pool variable in
get_bio_block() to eliminate redundant tc->pool dereferences.

No functional change.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:45 +00:00
Mikulas Patocka
3daec3b447 dm bufio: use WRITE_FLUSH instead of REQ_FLUSH
Use WRITE_FLUSH instead of REQ_FLUSH for submitted requests to make it
consistent with the rest of the kernel. There is no functional change.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:45 +00:00
Wang Sheng-Hui
d2ce70a119 dm table: remove superfluous variable reset
If allocation fails, the local var *t is not used any more after kfree.
Don't need to reset it to NULL. Remove the unnecesary NULL set here.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:45 +00:00
Mike Snitzer
f13945d757 dm thin: support a non power of 2 discard_granularity
Support a non-power-of-2 discard granularity in dm-thin, now that the block
layer supports this(via 8dd2cb7e88 "block:
discard granularity might not be power of 2" and
59771079c1 "blk: avoid divide-by-zero with zero
discard granularity").

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:44 +00:00
Mikulas Patocka
fd7c092e71 dm: fix truncated status strings
Avoid returning a truncated table or status string instead of setting
the DM_BUFFER_FULL_FLAG when the last target of a table fills the
buffer.

When processing a table or status request, the function retrieve_status
calls ti->type->status. If ti->type->status returns non-zero,
retrieve_status assumes that the buffer overflowed and sets
DM_BUFFER_FULL_FLAG.

However, targets don't return non-zero values from their status method
on overflow. Most targets returns always zero.

If a buffer overflow happens in a target that is not the last in the
table, it gets noticed during the next iteration of the loop in
retrieve_status; but if a buffer overflow happens in the last target, it
goes unnoticed and erroneously truncated data is returned.

In the current code, the targets behave in the following way:
* dm-crypt returns -ENOMEM if there is not enough space to store the
  key, but it returns 0 on all other overflows.
* dm-thin returns errors from the status method if a disk error happened.
  This is incorrect because retrieve_status doesn't check the error
  code, it assumes that all non-zero values mean buffer overflow.
* all the other targets always return 0.

This patch changes the ti->type->status function to return void (because
most targets don't use the return code). Overflow is detected in
retrieve_status: if the status method fills up the remaining space
completely, it is assumed that buffer overflow happened.

Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:44 +00:00
Jun'ichi Nomura
16245bdc9d dm: do not replace bioset for request based dm
This patch fixes a regression introduced in v3.8, which causes oops
like this when dm-multipath is used:

general protection fault: 0000 [#1] SMP
RIP: 0010:[<ffffffff810fe754>]  [<ffffffff810fe754>] mempool_free+0x24/0xb0
Call Trace:
  <IRQ>
  [<ffffffff81187417>] bio_put+0x97/0xc0
  [<ffffffffa02247a5>] end_clone_bio+0x35/0x90 [dm_mod]
  [<ffffffff81185efd>] bio_endio+0x1d/0x30
  [<ffffffff811f03a3>] req_bio_endio.isra.51+0xa3/0xe0
  [<ffffffff811f2f68>] blk_update_request+0x118/0x520
  [<ffffffff811f3397>] blk_update_bidi_request+0x27/0xa0
  [<ffffffff811f343c>] blk_end_bidi_request+0x2c/0x80
  [<ffffffff811f34d0>] blk_end_request+0x10/0x20
  [<ffffffffa000b32b>] scsi_io_completion+0xfb/0x6c0 [scsi_mod]
  [<ffffffffa000107d>] scsi_finish_command+0xbd/0x120 [scsi_mod]
  [<ffffffffa000b12f>] scsi_softirq_done+0x13f/0x160 [scsi_mod]
  [<ffffffff811f9fd0>] blk_done_softirq+0x80/0xa0
  [<ffffffff81044551>] __do_softirq+0xf1/0x250
  [<ffffffff8142ee8c>] call_softirq+0x1c/0x30
  [<ffffffff8100420d>] do_softirq+0x8d/0xc0
  [<ffffffff81044885>] irq_exit+0xd5/0xe0
  [<ffffffff8142f3e3>] do_IRQ+0x63/0xe0
  [<ffffffff814257af>] common_interrupt+0x6f/0x6f
  <EOI>
  [<ffffffffa021737c>] srp_queuecommand+0x8c/0xcb0 [ib_srp]
  [<ffffffffa0002f18>] scsi_dispatch_cmd+0x148/0x310 [scsi_mod]
  [<ffffffffa000a38e>] scsi_request_fn+0x31e/0x520 [scsi_mod]
  [<ffffffff811f1e57>] __blk_run_queue+0x37/0x50
  [<ffffffff811f1f69>] blk_delay_work+0x29/0x40
  [<ffffffff81059003>] process_one_work+0x1c3/0x5c0
  [<ffffffff8105b22e>] worker_thread+0x15e/0x440
  [<ffffffff8106164b>] kthread+0xdb/0xe0
  [<ffffffff8142db9c>] ret_from_fork+0x7c/0xb0

The regression was introduced by the change
c0820cf5 "dm: introduce per_bio_data", where dm started to replace
bioset during table replacement.
For bio-based dm, it is good because clone bios do not exist during the
table replacement.
For request-based dm, however, (not-yet-mapped) clone bios may stay in
request queue and survive during the table replacement.
So freeing the old bioset could cause the oops in bio_put().

Since the size of front_pad may change only with bio-based dm,
it is not necessary to replace bioset for request-based dm.

Reported-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01 22:45:44 +00:00
Linus Torvalds
ee89f81252 Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-block
Pull block IO core bits from Jens Axboe:
 "Below are the core block IO bits for 3.9.  It was delayed a few days
  since my workstation kept crashing every 2-8h after pulling it into
  current -git, but turns out it is a bug in the new pstate code (divide
  by zero, will report separately).  In any case, it contains:

   - The big cfq/blkcg update from Tejun and and Vivek.

   - Additional block and writeback tracepoints from Tejun.

   - Improvement of the should sort (based on queues) logic in the plug
     flushing.

   - _io() variants of the wait_for_completion() interface, using
     io_schedule() instead of schedule() to contribute to io wait
     properly.

   - Various little fixes.

  You'll get two trivial merge conflicts, which should be easy enough to
  fix up"

Fix up the trivial conflicts due to hlist traversal cleanups (commit
b67bfe0d42: "hlist: drop the node parameter from iterators").

* 'for-3.9/core' of git://git.kernel.dk/linux-block: (39 commits)
  block: remove redundant check to bd_openers()
  block: use i_size_write() in bd_set_size()
  cfq: fix lock imbalance with failed allocations
  drivers/block/swim3.c: fix null pointer dereference
  block: don't select PERCPU_RWSEM
  block: account iowait time when waiting for completion of IO request
  sched: add wait_for_completion_io[_timeout]
  writeback: add more tracepoints
  block: add block_{touch|dirty}_buffer tracepoint
  buffer: make touch_buffer() an exported function
  block: add @req to bio_{front|back}_merge tracepoints
  block: add missing block_bio_complete() tracepoint
  block: Remove should_sort judgement when flush blk_plug
  block,elevator: use new hashtable implementation
  cfq-iosched: add hierarchical cfq_group statistics
  cfq-iosched: collect stats from dead cfqgs
  cfq-iosched: separate out cfqg_stats_reset() from cfq_pd_reset_stats()
  blkcg: make blkcg_print_blkgs() grab q locks instead of blkcg lock
  block: RCU free request_queue
  blkcg: implement blkg_[rw]stat_recursive_sum() and blkg_[rw]stat_merge()
  ...
2013-02-28 12:52:24 -08:00
Sasha Levin
b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Tejun Heo
c9d76be696 dm: convert to idr_alloc()
Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:17 -08:00
Tejun Heo
adaedbd9fe dm: don't use idr_remove_all()
idr_destroy() can destroy idr by itself and idr_remove_all() is being
deprecated.  Drop its usage.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:13 -08:00
NeilBrown
f3378b4870 md: expedite metadata update when switching read-auto -> active
If something has failed while the array was read-auto,
then when we switch to 'active' we need to update the metadata.
This will happen anyway but it is good to expedite it, and
also to ensure any failed device has been released by the
underlying device before we try to action the ioctl which
caused us to switch to 'active' mode.

Reported-by: Joe Lawrence <Joe.Lawrence@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-28 11:59:03 +11:00
NeilBrown
51acbcec6c md: remove CONFIG_MULTICORE_RAID456
This doesn't seem to actually help and we have an alternate
multi-threading approach waiting in the wings, so just get
rid of this config option and associated code.

As a bonus, we remove one use of CONFIG_EXPERIMENTAL

Cc: Dan Williams <djbw@fb.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-28 09:08:34 +11:00
Linus Torvalds
d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
NeilBrown
ee0b024403 md/raid1,raid10: fix deadlock with freeze_array()
When raid1/raid10 needs to fix a read error, it first drains
all pending requests by calling freeze_array().
This calls flush_pending_writes() if it needs to sleep,
but some writes may be pending in a per-process plug rather
than in the per-array request queue.

When raid1{,0}_unplug() moves the request from the per-process
plug to the per-array request queue (from which
flush_pending_writes() can flush them), it needs to wake up
freeze_array(), or freeze_array() will never flush them and so
it will block forever.

So add the requires wake_up() calls.

This bug was introduced by commit
   f54a9d0e59
for raid1 and a similar commit for RAID10, and so has been present
since linux-3.6.  As the bug causes a deadlock I believe this fix is
suitable for -stable.

Cc: stable@vger.kernel.org (3.6.y 3.7.y 3.8.y)
Reported-by: Tregaron Bayly <tbayly@bluehost.com>
Tested-by: Tregaron Bayly <tbayly@bluehost.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-26 11:58:50 +11:00
NeilBrown
f96c9f305c md/raid0: improve error message when converting RAID4-with-spares to RAID0
Mentioning "bad disk number -1" exposes irrelevant internal detail.
Just say they are inactive and must be removed.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-26 11:58:44 +11:00
NeilBrown
58ebb34c49 md: raid0: fix error return from create_stripe_zones.
Create_stripe_zones returns an error slightly differently to
raid0_run and to raid0_takeover_*.

The error returned used by the second was wrong and an error would
result in mddev->private being set to NULL and sooner or later a
crash.

So never return NULL, return ERR_PTR(err), not NULL from
create_stripe_zones.

This bug has been present since 2.6.35 so the fix is suitable
for any kernel since then.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-26 11:57:04 +11:00
NeilBrown
a646853991 md: fix two bugs when attempting to resize RAID0 array.
You cannot resize a RAID0 array (in terms of making the devices
bigger), but the code doesn't entirely stop you.
So:

 disable setting of the available size on each device for
 RAID0 and Linear devices.  This must not change as doing so
 can change the effective layout of data.

 Make sure that the size that raid0_size() reports is accurate,
 but rounding devices sizes to chunk sizes.  As the device sizes
 cannot change now, this isn't so important, but it is best to be
 safe.

Without this change:
  mdadm --grow /dev/md0 -z max
  mdadm --grow /dev/md0 -Z max
  then read to the end of the array

can cause a BUG in a RAID0 array.

These bugs have been present ever since it became possible
to resize any device, which is a long time.  So the fix is
suitable for any -stable kerenl.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-26 11:55:40 +11:00
Jonathan Brassow
fe5d2f4a15 DM RAID: Add support for MD's RAID10 "far" and "offset" algorithms
DM RAID:  Add support for MD's RAID10 "far" and "offset" algorithms

Until now, dm-raid.c only supported the "near" algorthm of MD's RAID10
implementation.  This patch adds support for the "far" and "offset"
algorithms, but only with the improved redundancy that is brought with
the introduction of the 'use_far_sets' bit, which shifts copied stripes
according to smaller sets vs the entire array.  That is, the 17th bit
of the 'layout' variable that defines the RAID10 implementation will
always be set.   (More information on how the 'layout' variable selects
the RAID10 algorithm can be found in the opening comments of
drivers/md/raid10.c.)

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-26 11:55:36 +11:00
Jonathan Brassow
9a3152ab02 MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 2)
MD RAID10:  Improve redundancy for 'far' and 'offset' algorithms (part 2)

This patch addresses raid arrays that have a number of devices that cannot
be evenly divided by 'far_copies'.  (E.g. 5 devices, far_copies = 2)  This
case must be handled differently because it causes that last set to be of
a different size than the rest of the sets.  We must compute a new modulo
for this last set so that copied chunks are properly wrapped around.

Example use_far_sets=1, far_copies=2, near_copies=1, devices=5:
                "far" algorithm
        dev1 dev2 dev3 dev4 dev5
	==== ==== ==== ==== ====
	[ A   B ] [ C    D   E ]
        [ G   H ] [ I    J   K ]
                    ...
        [ B   A ] [ E    C   D ] --> nominal set of 2 and last set of 3
        [ H   G ] [ K    I   J ]     []'s show far/offset sets

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-26 11:55:33 +11:00
Jonathan Brassow
475901aff1 MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1)
The MD RAID10 'far' and 'offset' algorithms make copies of entire stripe
widths - copying them to a different location on the same devices after
shifting the stripe.  An example layout of each follows below:

	        "far" algorithm
	dev1 dev2 dev3 dev4 dev5 dev6
	==== ==== ==== ==== ==== ====
	 A    B    C    D    E    F
	 G    H    I    J    K    L
	            ...
	 F    A    B    C    D    E  --> Copy of stripe0, but shifted by 1
	 L    G    H    I    J    K
	            ...

		"offset" algorithm
	dev1 dev2 dev3 dev4 dev5 dev6
	==== ==== ==== ==== ==== ====
	 A    B    C    D    E    F
	 F    A    B    C    D    E  --> Copy of stripe0, but shifted by 1
	 G    H    I    J    K    L
	 L    G    H    I    J    K
	            ...

Redundancy for these algorithms is gained by shifting the copied stripes
one device to the right.  This patch proposes that array be divided into
sets of adjacent devices and when the stripe copies are shifted, they wrap
on set boundaries rather than the array size boundary.  That is, for the
purposes of shifting, the copies are confined to their sets within the
array.  The sets are 'near_copies * far_copies' in size.

The above "far" algorithm example would change to:
	        "far" algorithm
	dev1 dev2 dev3 dev4 dev5 dev6
	==== ==== ==== ==== ==== ====
	 A    B    C    D    E    F
	 G    H    I    J    K    L
	            ...
	 B    A    D    C    F    E  --> Copy of stripe0, shifted 1, 2-dev sets
	 H    G    J    I    L    K      Dev sets are 1-2, 3-4, 5-6
	            ...

This has the affect of improving the redundancy of the array.  We can
always sustain at least one failure, but sometimes more than one can
be handled.  In the first examples, the pairs of devices that CANNOT fail
together are:
	(1,2) (2,3) (3,4) (4,5) (5,6) (1, 6) [40% of possible pairs]
In the example where the copies are confined to sets, the pairs of
devices that cannot fail together are:
	(1,2) (3,4) (5,6)                    [20% of possible pairs]

We cannot simply replace the old algorithms, so the 17th bit of the 'layout'
variable is used to indicate whether we use the old or new method of computing
the shift.  (This is similar to the way the 16th bit indicates whether the
"far" algorithm or the "offset" algorithm is being used.)

This patch only handles the cases where the number of total raid disks is
a multiple of 'far_copies'.  A follow-on patch addresses the condition where
this is not true.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-26 11:55:30 +11:00
Jonathan Brassow
4c0ca26bd2 MD RAID10: Minor non-functional code changes
Changes include assigning 'addr' from 's' instead of 'sector' to be
consistent with the way the code does it just a few lines later and
using '%=' vs a conditional and subtraction.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-26 11:55:27 +11:00
Joe Lawrence
c8dc9c6547 md: raid1,10: Handle REQ_WRITE_SAME flag in write bios
Set mddev queue's max_write_same_sectors to its chunk_sector value (before
disk_stack_limits merges the underlying disk limits.)  With that in place,
be sure to handle writes coming down from the block layer that have the
REQ_WRITE_SAME flag set.  That flag needs to be copied into any newly cloned
write bio.

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-26 11:55:21 +11:00
Andrew Morton
df8557982f drivers/md/persistent-data/dm-transaction-manager.c: rename HASH_SIZE
Fix the warning:

  drivers/md/persistent-data/dm-transaction-manager.c:28:1: warning: "HASH_SIZE" redefined
  In file included from include/linux/elevator.h:5,
                   from include/linux/blkdev.h:216,
                   from drivers/md/persistent-data/dm-block-manager.h:11,
                   from drivers/md/persistent-data/dm-transaction-manager.h:10,
                   from drivers/md/persistent-data/dm-transaction-manager.c:6:
  include/linux/hashtable.h:22:1: warning: this is the location of the previous definition

Cc: Alasdair Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 17:50:08 -08:00
Al Viro
496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Sebastian Riemer
bbfa57c0f2 md: protect against crash upon fsync on ro array
If an fsync occurs on a read-only array, we need to send a
completion for the IO and may not increment the active IO count.
Otherwise, we hit a bug trace and can't stop the MD array anymore.

By advice of Christoph Hellwig we return success upon a flush
request but we return -EROFS for other writes.
We detect flush requests by checking if the bio has zero sectors.

This patch is suitable to any -stable kernel to which it applies.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-02-21 13:28:09 +11:00
Linus Torvalds
cc6c954a07 A fix for stacked dm thin devices and a fix for the new dm WRITE SAME
support.
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Merge tag 'dm-3.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull more device-mapper fixes from Alasdair G Kergon:
 "A fix for stacked dm thin devices and a fix for the new dm WRITE SAME
  support."

* tag 'dm-3.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm: fix write same requests counting
  dm thin: fix queue limits stacking
2013-02-01 12:04:22 +11:00
Alasdair G Kergon
fe7af2d3ba dm: fix write same requests counting
When processing write same requests, fix dm to send the configured
number of WRITE SAME requests to the target rather than the number of
discards, which is not always the same.

Device-mapper WRITE SAME support was introduced by commit
23508a96cd ("dm: add WRITE SAME support").

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
2013-01-31 14:23:36 +00:00
Mike Snitzer
0f640dca08 dm thin: fix queue limits stacking
thin_io_hints() is blindly copying the queue limits from the thin-pool
which can lead to incorrect limits being set.  The fix here simply
deletes the thin_io_hints() hook which leaves the existing stacking
infrastructure to set the limits correctly.

When a thin-pool uses an MD device for the data device a thin device
from the thin-pool must respect MD's constraints about disallowing a bio
from spanning multiple chunks.  Otherwise we can see problems.  If the raid0
chunksize is 1152K and thin-pool chunksize is 256K I see the following
md/raid0 error (with extra debug tracing added to thin_endio) when
mkfs.xfs is executed against the thin device:

md/raid0:md99: make_request bug: can't convert block across chunks or bigger than 1152k 6688 127
device-mapper: thin: bio sector=2080 err=-5 bi_size=130560 bi_rw=17 bi_vcnt=32 bi_idx=0

This extra DM debugging shows that the failing bio is spanning across
the first and second logical 1152K chunk (sector 2080 + 255 takes the
bio beyond the first chunk's boundary of sector 2304).  So the bio
splitting that DM is doing clearly isn't respecting the MD limits.

max_hw_sectors_kb is 127 for both the thin-pool and thin device
(queue_max_hw_sectors returns 255 so we'll excuse sysfs's lack of
precision).  So this explains why bi_size is 130560.

But the thin device's max_hw_sectors_kb should be 4 (PAGE_SIZE) given
that it doesn't have a .merge function (for bio_add_page to consult
indirectly via dm_merge_bvec) yet the thin-pool does sit above an MD
device that has a compulsory merge_bvec_fn.  This scenario is exactly
why DM must resort to sending single PAGE_SIZE bios to the underlying
layer. Some additional context for this is available in the header for
commit 8cbeb67a ("dm: avoid unsupported spanning of md stripe boundaries").

Long story short, the reason a thin device doesn't properly get
configured to have a max_hw_sectors_kb of 4 (PAGE_SIZE) is that
thin_io_hints() is blindly copying the queue limits from the thin-pool
device directly to the thin device's queue limits.

Fix this by eliminating thin_io_hints.  Doing so is safe because the
block layer's queue limits stacking already enables the upper level thin
device to inherit the thin-pool device's discard and minimum_io_size and
optimal_io_size limits that get set in pool_io_hints.  But avoiding the
queue limits copy allows the thin and thin-pool limits to be different
where it is important, namely max_hw_sectors_kb.

Reported-by: Daniel Browning <db@kavod.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-01-31 14:11:14 +00:00
Jonathan Brassow
55ebbb59c1 DM-RAID: Fix RAID10's check for sufficient redundancy
Before attempting to activate a RAID array, it is checked for sufficient
redundancy.  That is, we make sure that there are not too many failed
devices - or devices specified for rebuild - to undermine our ability to
activate the array.  The current code performs this check twice - once to
ensure there were not too many devices specified for rebuild by the user
('validate_rebuild_devices') and again after possibly experiencing a failure
to read the superblock ('analyse_superblocks').  Neither of these checks are
sufficient.  The first check is done properly but with insufficient
information about the possible failure state of the devices to make a good
determination if the array can be activated.  The second check is simply
done wrong in the case of RAID10 because it doesn't account for the
independence of the stripes (i.e. mirror sets).  The solution is to use the
properly written check ('validate_rebuild_devices'), but perform the check
after the superblocks have been read and we know which devices have failed.
This gives us one check instead of two and performs it in a location where
it can be done right.

Only RAID10 was affected and it was affected in the following ways:
- the code did not properly catch the condition where a user specified
  a device for rebuild that already had a failed device in the same mirror
  set.  (This condition would, however, be caught at a deeper level in MD.)
- the code triggers a false positive and denies activation when devices in
  independent mirror sets have failed - counting the failures as though they
  were all in the same set.

The most likely place this error was introduced (or this patch should have
been included) is in commit 4ec1e369 - first introduced in v3.7-rc1.
Consequently this fix should also go in v3.7.y, however there is a
small conflict on the .version in raid_target, so I'll submit a
separate patch to -stable.

Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-01-24 12:02:36 +11:00
Tejun Heo
3a366e614d block: add missing block_bio_complete() tracepoint
bio completion didn't kick block_bio_complete TP.  Only dm was
explicitly triggering the TP on IO completion.  This makes
block_bio_complete TP useless for tracers which want to know about
bios, and all other bio based drivers skip generating blktrace
completion events.

This patch makes all bio completions via bio_endio() generate
block_bio_complete TP.

* Explicit trace_block_bio_complete() invocation removed from dm and
  the trace point is unexported.

* @rq dropped from trace_block_bio_complete().  bios may fly around
  w/o queue associated.  Verifying and accessing the assocaited queue
  belongs to TP probes.

* blktrace now gets both request and bio completions.  Make it ignore
  bio completions if request completion path is happening.

This makes all bio based drivers generate blktrace completion events
properly and makes the block_bio_complete TP actually useful.

v2: With this change, block_bio_complete TP could be invoked on sg
    commands which have bio's with %NULL bi_bdev.  Update TP
    assignment code to check whether bio->bi_bdev is %NULL before
    dereferencing.

Signed-off-by: Tejun Heo <tj@kernel.org>
Original-patch-by: Namhyung Kim <namhyung@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-01-14 15:00:36 +01:00
Linus Torvalds
b49249d103 Miscellaneous device-mapper fixes, cleanups and performance improvements.
Of particular note:
 - Disable broken WRITE SAME support in all targets except linear and striped.
   Use it when kcopyd is zeroing blocks.
 - Remove several mempools from targets by moving the data into the bio's new
   front_pad area(which dm calls 'per_bio_data').
 - Fix a race in thin provisioning if discards are misused.
 - Prevent userspace from interfering with the ioctl parameters and
   use kmalloc for the data buffer if it's small instead of vmalloc.
 - Throttle some annoying error messages when I/O fails.
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Merge tag 'dm-3.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull dm update from Alasdair G Kergon:
 "Miscellaneous device-mapper fixes, cleanups and performance
  improvements.

  Of particular note:
   - Disable broken WRITE SAME support in all targets except linear and
     striped.  Use it when kcopyd is zeroing blocks.
   - Remove several mempools from targets by moving the data into the
     bio's new front_pad area(which dm calls 'per_bio_data').
   - Fix a race in thin provisioning if discards are misused.
   - Prevent userspace from interfering with the ioctl parameters and
     use kmalloc for the data buffer if it's small instead of vmalloc.
   - Throttle some annoying error messages when I/O fails."

* tag 'dm-3.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: (36 commits)
  dm stripe: add WRITE SAME support
  dm: remove map_info
  dm snapshot: do not use map_context
  dm thin: dont use map_context
  dm raid1: dont use map_context
  dm flakey: dont use map_context
  dm raid1: rename read_record to bio_record
  dm: move target request nr to dm_target_io
  dm snapshot: use per_bio_data
  dm verity: use per_bio_data
  dm raid1: use per_bio_data
  dm: introduce per_bio_data
  dm kcopyd: add WRITE SAME support to dm_kcopyd_zero
  dm linear: add WRITE SAME support
  dm: add WRITE SAME support
  dm: prepare to support WRITE SAME
  dm ioctl: use kmalloc if possible
  dm ioctl: remove PF_MEMALLOC
  dm persistent data: improve improve space map block alloc failure message
  dm thin: use DMERR_LIMIT for errors
  ...
2012-12-21 17:08:06 -08:00
Mike Snitzer
45e621d45e dm stripe: add WRITE SAME support
Rename stripe_map_discard to stripe_map_range and reuse it for WRITE
SAME bio processing.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:41 +00:00
Mikulas Patocka
7de3ee57da dm: remove map_info
This patch removes map_info from bio-based device mapper targets.
map_info is still used for request-based targets.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:41 +00:00
Mikulas Patocka
ee18026ac6 dm snapshot: do not use map_context
Eliminate struct map_info from dm-snap.

map_info->ptr was used in dm-snap to indicate if the bio was tracked.
If map_info->ptr was non-NULL, the bio was linked in tracked_chunk_hash.

This patch removes the use of map_info->ptr. We determine if the bio was
tracked based on hlist_unhashed(&c->node). If hlist_unhashed is true,
the bio is not tracked, if it is false, the bio is tracked.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:41 +00:00
Mikulas Patocka
59c3d2c6a1 dm thin: dont use map_context
This patch removes endio_hook_pool from dm-thin and uses per-bio data instead.

This patch removes any use of map_info in preparation for the next patch
that removes map_info from bio-based device mapper.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:40 +00:00
Mikulas Patocka
0045d61b5b dm raid1: dont use map_context
Don't use map_info any more in dm-raid1.

map_info was used for writes to hold the region number. For this purpose
we add a new field dm_bio_details to dm_raid1_bio_record.

map_info was used for reads to hold a pointer to dm_raid1_bio_record (if
the pointer was non-NULL, bio details were saved; if the pointer was
NULL, bio details were not saved). We use
dm_raid1_bio_record.details->bi_bdev for this purpose. If bi_bdev is
NULL, details were not saved, if bi_bdev is non-NULL, details were
saved.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:40 +00:00
Mikulas Patocka
c7cfdf5973 dm flakey: dont use map_context
Replace map_info with a per-bio structure "struct per_bio_data" in dm-flakey.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:39 +00:00
Mikulas Patocka
89c7cd8974 dm raid1: rename read_record to bio_record
Rename struct read_record to bio_record in dm-raid1.

In the following patch, the structure will be used for both read and
write bios, so rename it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:39 +00:00
Mikulas Patocka
ddbd658f64 dm: move target request nr to dm_target_io
This patch moves target_request_nr from map_info to dm_target_io and
makes it accessible with dm_bio_get_target_request_nr.

This patch is a preparation for the next patch that removes map_info.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:39 +00:00
Mikulas Patocka
42bc954f2a dm snapshot: use per_bio_data
Replace tracked_chunk_pool with per_bio_data in dm-snap.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:38 +00:00
Mikulas Patocka
e42c3f914d dm verity: use per_bio_data
Replace io_mempool with per_bio_data in dm-verity.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:38 +00:00
Mikulas Patocka
39cf0ed27e dm raid1: use per_bio_data
Replace read_record_pool with per_bio_data in dm-raid1.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:38 +00:00
Mikulas Patocka
c0820cf5ad dm: introduce per_bio_data
Introduce a field per_bio_data_size in struct dm_target.

Targets can set this field in the constructor. If a target sets this
field to a non-zero value, "per_bio_data_size" bytes of auxiliary data
are allocated for each bio submitted to the target. These data can be
used for any purpose by the target and help us improve performance by
removing some per-target mempools.

Per-bio data is accessed with dm_per_bio_data. The
argument data_size must be the same as the value per_bio_data_size in
dm_target.

If the target has a pointer to per_bio_data, it can get a pointer to
the bio with dm_bio_from_per_bio_data() function (data_size must be the
same as the value passed to dm_per_bio_data).

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:38 +00:00
Mike Snitzer
70d6c400ac dm kcopyd: add WRITE SAME support to dm_kcopyd_zero
Add WRITE SAME support to dm-io and make it accessible to
dm_kcopyd_zero().  dm_kcopyd_zero() provides an asynchronous interface
whereas the blkdev_issue_write_same() interface is synchronous.

WRITE SAME is a SCSI command that can be leveraged for more efficient
zeroing of a specified logical extent of a device which supports it.
Only a single zeroed logical block is transfered to the target for each
WRITE SAME and the target then writes that same block across the
specified extent.

The dm thin target uses this.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:37 +00:00
Mike Snitzer
4f0b70b047 dm linear: add WRITE SAME support
The linear target can already support WRITE SAME requests so signal
this by setting num_write_same_requests to 1.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:37 +00:00
Mike Snitzer
23508a96cd dm: add WRITE SAME support
WRITE SAME bios have a payload that contain a single page.  When
cloning WRITE SAME bios DM has no need to modify the bi_io_vec
attributes (and doing so would be detrimental).  DM need only alter the
start and end of the WRITE SAME bio accordingly.

Rather than duplicate __clone_and_map_discard, factor out a common
function that is also used by __clone_and_map_write_same.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:37 +00:00
Mike Snitzer
d54eaa5a0f dm: prepare to support WRITE SAME
Allow targets to opt in to WRITE SAME support by setting
'num_write_same_requests' in the dm_target structure.

A dm device will only advertise WRITE SAME support if all its
targets and all its underlying devices support it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:36 +00:00
Mikulas Patocka
9c5091f2ee dm ioctl: use kmalloc if possible
If the parameter buffer is small enough, try to allocate it with kmalloc()
rather than vmalloc().

vmalloc is noticeably slower than kmalloc because it has to manipulate
page tables.

In my tests, on PA-RISC this patch speeds up activation 13 times.
On Opteron this patch speeds up activation by 5%.

This patch introduces a new function free_params() to free the
parameters and this uses new flags that record whether or not vmalloc()
was used and whether or not the input buffer must be wiped after use.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:36 +00:00
Mikulas Patocka
5023e5cf58 dm ioctl: remove PF_MEMALLOC
When allocating memory for the userspace ioctl data, set some
appropriate GPF flags directly instead of using PF_MEMALLOC.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:36 +00:00
Joe Thornber
7960123f2d dm persistent data: improve improve space map block alloc failure message
Improve space map error message when unable to allocate a new
metadata block.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:36 +00:00
Mike Snitzer
c397741c76 dm thin: use DMERR_LIMIT for errors
Throttle all errors logged from the IO path by dm thin.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:34 +00:00
Mike Snitzer
89ddeb8cb1 dm persistent data: use DMERR_LIMIT for errors
Nearly all of persistent-data is in the IO path so throttle error
messages with DMERR_LIMIT to limit the amount logged when
something has gone wrong.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:34 +00:00
Mike Snitzer
a5bd968aeb dm block manager: reinstate message when validator fails
Reinstate a useful error message when the block manager buffer validator fails.
This was mistakenly eliminated when the block manager was converted to use
dm-bufio.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:34 +00:00
Jonathan Brassow
3a0f9aaee0 dm raid: round region_size to power of two
If the user does not supply a bitmap region_size to the dm raid target,
a reasonable size is computed automatically.  If this is not a power of 2,
the md code will report an error later.

This patch catches the problem early and rounds the region_size to the
next power of two.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:33 +00:00
Joe Thornber
2aab38502d dm thin: cleanup dead code
Remove unused @data_block parameter from cell_defer.
Change thin_bio_map to use many returns rather than setting a variable.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:33 +00:00
Joe Thornber
f286ba0eed dm thin: rename cell_defer_except to cell_defer_no_holder
Rename cell_defer_except() to cell_defer_no_holder() which describes
its function more clearly.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:33 +00:00
Mikulas Patocka
9aa0c0e60f dm snapshot: optimize track_chunk
track_chunk is always called with interrupts enabled. Consequently, we
do not need to save and restore interrupt state in "flags" variable.
This patch changes spin_lock_irqsave to spin_lock_irq and
spin_unlock_irqrestore to spin_unlock_irq.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:33 +00:00
Mikulas Patocka
19cbbc60c6 dm raid: use DM_ENDIO_INCOMPLETE
Use a defined macro DM_ENDIO_INCOMPLETE instead of a numeric constant.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:32 +00:00
Mikulas Patocka
7c27213b20 dm raid1: remove impossible mempool_alloc error test
mempool_alloc can't fail if __GFP_WAIT is specified, so the condition
that tests if read_record is non-NULL is always true.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:32 +00:00
Mike Snitzer
018debea8d dm thin: emit ignore_discard in status when discards disabled
If "ignore_discard" is specified when creating the thin pool device then
discard support is disabled for that device.  The pool device's status
should reflect this fact rather than stating "no_discard_passdown"
(which implies discards are enabled but passdown is disabled).

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:32 +00:00
Joe Thornber
e3cbf94513 dm persistent data: fix nested btree deletion
When deleting nested btrees, the code forgets to delete the innermost
btree.  The thin-metadata code serendipitously compensates for this by
claiming there is one extra layer in the tree.

This patch corrects both problems.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:32 +00:00
Joe Thornber
563af186df dm thin: wake worker when discard is prepared
When discards are prepared it is best to directly wake the worker that
will process them.  The worker will be woken anyway, via periodic
commit, but there is no reason to not wake_worker here.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:31 +00:00
Joe Thornber
e8088073c9 dm thin: fix race between simultaneous io and discards to same block
There is a race when discard bios and non-discard bios are issued
simultaneously to the same block.

Discard support is expensive for all thin devices precisely because you
have to be careful to quiesce the area you're discarding.  DM thin must
handle this conflicting IO pattern (simultaneous non-discard vs discard)
even though a sane application shouldn't be issuing such IO.

The race manifests as follows:

1. A non-discard bio is mapped in thin_bio_map.
   This doesn't lock out parallel activity to the same block.

2. A discard bio is issued to the same block as the non-discard bio.

3. The discard bio is locked in a dm_bio_prison_cell in process_discard
   to lock out parallel activity against the same block.

4. The non-discard bio's mapping continues and its all_io_entry is
   incremented so the bio is accounted for in the thin pool's all_io_ds
   which is a dm_deferred_set used to track time locality of non-discard IO.

5. The non-discard bio is finally locked in a dm_bio_prison_cell in
   process_bio.

The race can result in deadlock, leaving the block layer hanging waiting
for completion of a discard bio that never completes, e.g.:

INFO: task ruby:15354 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
ruby            D ffffffff8160f0e0     0 15354  15314 0x00000000
 ffff8802fb08bc58 0000000000000082 ffff8802fb08bfd8 0000000000012900
 ffff8802fb08a010 0000000000012900 0000000000012900 0000000000012900
 ffff8802fb08bfd8 0000000000012900 ffff8803324b9480 ffff88032c6f14c0
Call Trace:
 [<ffffffff814e5a19>] schedule+0x29/0x70
 [<ffffffff814e3d85>] schedule_timeout+0x195/0x220
 [<ffffffffa06b9bc1>] ? _dm_request+0x111/0x160 [dm_mod]
 [<ffffffff814e589e>] wait_for_common+0x11e/0x190
 [<ffffffff8107a170>] ? try_to_wake_up+0x2b0/0x2b0
 [<ffffffff814e59ed>] wait_for_completion+0x1d/0x20
 [<ffffffff81233289>] blkdev_issue_discard+0x219/0x260
 [<ffffffff81233e79>] blkdev_ioctl+0x6e9/0x7b0
 [<ffffffff8119a65c>] block_ioctl+0x3c/0x40
 [<ffffffff8117539c>] do_vfs_ioctl+0x8c/0x340
 [<ffffffff8119a547>] ? block_llseek+0x67/0xb0
 [<ffffffff811756f1>] sys_ioctl+0xa1/0xb0
 [<ffffffff810561f6>] ? sys_rt_sigprocmask+0x86/0xd0
 [<ffffffff814ef099>] system_call_fastpath+0x16/0x1b

The thinp-test-suite's test_discard_random_sectors reliably hits this
deadlock on fast SSD storage.

The fix for this race is that the all_io_entry for a bio must be
incremented whilst the dm_bio_prison_cell is held for the bio's
associated virtual and physical blocks.  That cell locking wasn't
occurring early enough in thin_bio_map.  This patch fixes this.

Care is taken to always call the new function inc_all_io_entry() with
the relevant cells locked, but they are generally unlocked before
calling issue() to try to avoid holding the cells locked across
generic_submit_request.

Also, now that thin_bio_map may lock bios in a cell, process_bio() is no
longer the only thread that will do so.  Because of this we must be sure
to use cell_defer_except() to release all non-holder entries, that
were added by the other thread, because they must be deferred.

This patch depends on "dm thin: replace dm_cell_release_singleton with
cell_defer_except".

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@vger.kernel.org
2012-12-21 20:23:31 +00:00
Joe Thornber
b7ca9c9273 dm thin: replace dm_cell_release_singleton with cell_defer_except
Change existing users of the function dm_cell_release_singleton to share
cell_defer_except instead, and then remove the now-unused function.

Everywhere that calls dm_cell_release_singleton, the bio in question
is the holder of the cell.

If there are no non-holder entries in the cell then cell_defer_except
behaves exactly like dm_cell_release_singleton.  Conversely, if there
*are* non-holder entries then dm_cell_release_singleton must not be used
because those entries would need to be deferred.

Consequently, it is safe to replace use of dm_cell_release_singleton
with cell_defer_except.

This patch is a pre-requisite for "dm thin: fix race between
simultaneous io and discards to same block".

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:31 +00:00
Mike Snitzer
c1a94672a8 dm: disable WRITE SAME
WRITE SAME bios are not yet handled correctly by device-mapper so
disable their use on device-mapper devices by setting
max_write_same_sectors to zero.

As an example, a ciphertext device is incompatible because the data
gets changed according to the location at which it written and so the
dm crypt target cannot support it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Cc: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:30 +00:00
Alasdair G Kergon
e910d7ebec dm ioctl: prevent unsafe change to dm_ioctl data_size
Abort dm ioctl processing if userspace changes the data_size parameter
after we validated it but before we finished copying the data buffer
from userspace.

The dm ioctl parameters are processed in the following sequence:
 1. ctl_ioctl() calls copy_params();
 2. copy_params() makes a first copy of the fixed-sized portion of the
    userspace parameters into the local variable "tmp";
 3. copy_params() then validates tmp.data_size and allocates a new
    structure big enough to hold the complete data and copies the whole
    userspace buffer there;
 4. ctl_ioctl() reads userspace data the second time and copies the whole
    buffer into the pointer "param";
 5. ctl_ioctl() reads param->data_size without any validation and stores it
    in the variable "input_param_size";
 6. "input_param_size" is further used as the authoritative size of the
    kernel buffer.

The problem is that userspace code could change the contents of user
memory between steps 2 and 4.  In particular, the data_size parameter
can be changed to an invalid value after the kernel has validated it.
This lets userspace force the kernel to access invalid kernel memory.

The fix is to ensure that the size has not changed at step 4.

This patch shouldn't have a security impact because CAP_SYS_ADMIN is
required to run this code, but it should be fixed anyway.

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
2012-12-21 20:23:30 +00:00
Mikulas Patocka
550929faf8 dm persistent data: rename node to btree_node
This patch fixes a compilation failure on sparc32 by renaming struct node.

struct node is already defined in include/linux/node.h. On sparc32, it
happens to be included through other dependencies and persistent-data
doesn't compile because of conflicting declarations.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21 20:23:30 +00:00
Linus Torvalds
ea88eeac0c md update for 3.8
Mostly just little fixes.  Probably biggest part is
 AVX accelerated RAID6 calculations.
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Merge tag 'md-3.8' of git://neil.brown.name/md

Pull md update from Neil Brown:
 "Mostly just little fixes.  Probably biggest part is AVX accelerated
  RAID6 calculations."

* tag 'md-3.8' of git://neil.brown.name/md:
  md/raid5: add blktrace calls
  md/raid5: use async_tx_quiesce() instead of open-coding it.
  md: Use ->curr_resync as last completed request when cleanly aborting resync.
  lib/raid6: build proper files on corresponding arch
  lib/raid6: Add AVX2 optimized gen_syndrome functions
  lib/raid6: Add AVX2 optimized recovery functions
  md: Update checkpoint of resync/recovery based on time.
  md:Add place to update ->recovery_cp.
  md.c: re-indent various 'switch' statements.
  md: close race between removing and adding a device.
  md: removed unused variable in calc_sb_1_csm.
2012-12-18 09:32:44 -08:00
NeilBrown
a9add5d92b md/raid5: add blktrace calls
This makes it easier to trace what raid5 is doing.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-18 10:22:21 +11:00
Linus Torvalds
9228ff9038 Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-block
Pull block driver update from Jens Axboe:
 "Now that the core bits are in, here are the driver bits for 3.8.  The
  branch contains:

   - A huge pile of drbd bits that were dumped from the 3.7 merge
     window.  Following that, it was both made perfectly clear that
     there is going to be no more over-the-wall pulls and how the
     situation on individual pulls can be improved.

   - A few cleanups from Akinobu Mita for drbd and cciss.

   - Queue improvement for loop from Lukas.  This grew into adding a
     generic interface for waiting/checking an even with a specific
     lock, allowing this to be pulled out of md and now loop and drbd is
     also using it.

   - A few fixes for xen back/front block driver from Roger Pau Monne.

   - Partition improvements from Stephen Warren, allowing partiion UUID
     to be used as an identifier."

* 'for-3.8/drivers' of git://git.kernel.dk/linux-block: (609 commits)
  drbd: update Kconfig to match current dependencies
  drbd: Fix drbdsetup wait-connect, wait-sync etc... commands
  drbd: close race between drbd_set_role and drbd_connect
  drbd: respect no-md-barriers setting also when changed online via disk-options
  drbd: Remove obsolete check
  drbd: fixup after wait_even_lock_irq() addition to generic code
  loop: Limit the number of requests in the bio list
  wait: add wait_event_lock_irq() interface
  xen-blkfront: free allocated page
  xen-blkback: move free persistent grants code
  block: partition: msdos: provide UUIDs for partitions
  init: reduce PARTUUID min length to 1 from 36
  block: store partition_meta_info.uuid as a string
  cciss: use check_signature()
  cciss: cleanup bitops usage
  drbd: use copy_highpage
  drbd: if the replication link breaks during handshake, keep retrying
  drbd: check return of kmalloc in receive_uuids
  drbd: Broadcast sync progress no more often than once per second
  drbd: don't try to clear bits once the disk has failed
  ...
2012-12-17 13:39:11 -08:00
Linus Torvalds
a2013a13e6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial branch from Jiri Kosina:
 "Usual stuff -- comment/printk typo fixes, documentation updates, dead
  code elimination."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  HOWTO: fix double words typo
  x86 mtrr: fix comment typo in mtrr_bp_init
  propagate name change to comments in kernel source
  doc: Update the name of profiling based on sysfs
  treewide: Fix typos in various drivers
  treewide: Fix typos in various Kconfig
  wireless: mwifiex: Fix typo in wireless/mwifiex driver
  messages: i2o: Fix typo in messages/i2o
  scripts/kernel-doc: check that non-void fcts describe their return value
  Kernel-doc: Convention: Use a "Return" section to describe return values
  radeon: Fix typo and copy/paste error in comments
  doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c
  various: Fix spelling of "asynchronous" in comments.
  Fix misspellings of "whether" in comments.
  eisa: Fix spelling of "asynchronous".
  various: Fix spelling of "registered" in comments.
  doc: fix quite a few typos within Documentation
  target: iscsi: fix comment typos in target/iscsi drivers
  treewide: fix typo of "suport" in various comments and Kconfig
  treewide: fix typo of "suppport" in various comments
  ...
2012-12-13 12:00:02 -08:00
NeilBrown
749586b7d3 md/raid5: use async_tx_quiesce() instead of open-coding it.
handle_stripe_expansion contains:

        if (tx) {
                async_tx_ack(tx);
                dma_wait_for_async_tx(tx);
        }

which is very similar to the body of async_tx_quiesce(),
except that the later handles an error from dma_wait_for_async_tx()
(admittedly by panicing, but that decision belongs in the dma
code, not the md code).

So just us async_tx_quiesce().

Acked-by: Dan Williams <djbw@fb.com>
Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-13 19:52:32 +11:00
majianpeng
0a19caabf0 md: Use ->curr_resync as last completed request when cleanly aborting resync.
If a resync is aborted cleanly, ->curr_resync is a reliable
record of where we got up to.
If there was an error it is less reliable but we always know that
->curr_resync_completed is safe.

So add a flag MD_RECOVERY_ERROR to differentiate between these cases
and set recovery_cp accordingly.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-13 19:52:11 +11:00
majianpeng
54f89341e8 md: Update checkpoint of resync/recovery based on time.
md will current only only checkpoint recovery or resync ever 1/16th
of the device size.  As devices get larger this can become a long time
an so a lot of work that might need to be duplicated after a shutdown.

So add a time-based checkpoint.  Every 5 minutes limits the amount of
duplicated effort to at most 5 minutes, and has almost zero impact on
performance.

[changelog entry re-written by NeilBrown]

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-13 16:41:40 +11:00
kernelmail
35d78c6696 md:Add place to update ->recovery_cp.
In resyncing, recovery_cp only updated when resync aborted or completed.
But in md drives,many place used it to judge.So add a place to update.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-13 16:41:01 +11:00
NeilBrown
c02c0aeb6c md.c: re-indent various 'switch' statements.
Intent was unnecessarily deep.

Also change one 'switch' which has a single case element, into an
'if'.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-11 13:39:21 +11:00
NeilBrown
a7a3f08dc2 md: close race between removing and adding a device.
When we remove a device from an md array, the final removal of
the "dev-XX" sys entry is run asynchronously.
If we then re-add that device immediately before the worker thread
gets to run, we can end up trying to add the "dev-XX" sysfs entry back
before it has been removed.

So in both places where we add a device, call
  flush_workqueue(md_misc_wq);
before taking the md lock (as holding the md lock can prevent removal
to complete).

Signed-off-by: NeilBrown <neilb@suse.de>
2012-12-11 13:35:54 +11:00
NeilBrown
1f3c9907b8 md: removed unused variable in calc_sb_1_csm.
'i' is unused.

NeilBrown <neilb@suse.de>
2012-12-11 13:09:00 +11:00
Linus Torvalds
4ccc804586 Single bugfix for raid1/raid10.
Fixes a recently introduced deadlock.
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Merge tag 'md-3.7-fixes' of git://neil.brown.name/md

Pull md bugfix from NeilBrown:
 "Single bugfix for raid1/raid10.

  Fixes a recently introduced deadlock."

* tag 'md-3.7-fixes' of git://neil.brown.name/md:
  md/raid1{,0}: fix deadlock in bitmap_unplug.
2012-12-02 16:24:31 -08:00
Lukas Czerner
eed8c02e68 wait: add wait_event_lock_irq() interface
New wait_event{_interruptible}_lock_irq{_cmd} macros added. This commit
moves the private wait_event_lock_irq() macro from MD to regular wait
includes, introduces new macro wait_event_lock_irq_cmd() instead of using
the old method with omitting cmd parameter which is ugly and makes a use
of new macros in the MD. It also introduces the _interruptible_ variant.

The use of new interface is when one have a special lock to protect data
structures used in the condition, or one also needs to invoke "cmd"
before putting it to sleep.

All new macros are expected to be called with the lock taken. The lock
is released before sleep and is reacquired afterwards. We will leave the
macro with the lock held.

Note to DM: IMO this should also fix theoretical race on waitqueue while
using simultaneously wait_event_lock_irq() and wait_event() because of
lack of locking around current state setting and wait queue removal.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-11-30 11:47:57 +01:00
NeilBrown
874807a831 md/raid1{,0}: fix deadlock in bitmap_unplug.
If the raid1 or raid10 unplug function gets called
from a make_request function (which is very possible) when
there are bios on the current->bio_list list, then it will not
be able to successfully call bitmap_unplug() and it could
need to submit more bios and wait for them to complete.
But they won't complete while current->bio_list is non-empty.

So detect that case and handle the unplugging off to another thread
just like we already do when called from within the scheduler.

RAID1 version of bug was introduced in 3.6, so that part of fix is
suitable for 3.6.y.  RAID10 part won't apply.

Cc: stable@vger.kernel.org
Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com>
Reported-by: Peter Maloney <peter.maloney@brockmann-consult.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-27 12:14:40 +11:00
Linus Torvalds
1d838d70fb Several bug fixes for md in 3.7
- raid5 discard has problems
  - raid10 replacement devices have problems
  - bad block lock seqlock usage has problems
  - dm-raid doesn't free everything
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Merge tag 'md-3.7-fixes' of git://neil.brown.name/md

Pull md fixes from NeilBrown:
 "Several bug fixes for md in 3.7:

   - raid5 discard has problems
   - raid10 replacement devices have problems
   - bad block lock seqlock usage has problems
   - dm-raid doesn't free everything"

* tag 'md-3.7-fixes' of git://neil.brown.name/md:
  md/raid10: decrement correct pending counter when writing to replacement.
  md/raid10: close race that lose writes lost when replacement completes.
  md/raid5: Make sure we clear R5_Discard when discard is finished.
  md/raid5: move resolving of reconstruct_state earlier in stripe_handle.
  md/raid5: round discard alignment up to power of 2.
  md: make sure everything is freed when dm-raid stops an array.
  md: Avoid write invalid address if read_seqretry returned true.
  md: Reassigned the parameters if read_seqretry returned true in func md_is_badblock.
2012-11-23 12:11:13 -10:00
Jens Axboe
a8c32a5c98 dm: fix deadlock with request based dm and queue request_fn recursion
Request based dm attempts to re-run the request queue off the
request completion path. If used with a driver that potentially does
end_io from its request_fn, we could deadlock trying to recurse
back into request dispatch. Fix this by punting the request queue
run to kblockd.

Tested to fix a quickly reproducible deadlock in such a scenario.

Cc: stable@kernel.org
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-11-23 14:32:54 +01:00
NeilBrown
884162df2a md/raid10: decrement correct pending counter when writing to replacement.
When a write to a replacement device completes, we carefully
and correctly found the rdev that the write actually went to
and the blithely called rdev_dec_pending on the primary rdev,
even if this write was to the replacement.

This means that any writes to an array while a replacement
was ongoing would cause the nr_pending count for the primary
device to go negative, so it could never be removed.

This bug has been present since replacement was introduced in
3.3, so it is suitable for any -stable kernel since then.

Reported-by: "George Spelvin" <linux@horizon.com>
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-22 15:12:42 +11:00
NeilBrown
e7c0c3fa29 md/raid10: close race that lose writes lost when replacement completes.
When a replacement operation completes there is a small window
when the original device is marked 'faulty' and the replacement
still looks like a replacement.  The faulty should be removed and
the replacement moved in place very quickly, bit it isn't instant.

So the code write out to the array must handle the possibility that
the only working device for some slot in the replacement - but it
doesn't.  If the primary device is faulty it just gives up.  This
can lead to corruption.

So make the code more robust: if either  the primary or the
replacement is present and working, write to them.  Only when
neither are present do we give up.

This bug has been present since replacement was introduced in
3.3, so it is suitable for any -stable kernel since then.

Reported-by: "George Spelvin" <linux@horizon.com>
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-22 15:12:36 +11:00
NeilBrown
ca64cae960 md/raid5: Make sure we clear R5_Discard when discard is finished.
commit 9e44476851
    MD: raid5 avoid unnecessary zero page for trim

change raid5 to clear R5_Discard when the complete request is
handled rather than when submitting the per-device discard request.
However it did not clear R5_Discard for the parity device.

This means that if the stripe_head was reused before it expired from
the cache, the setting would be wrong and a hang would result.

Also if the R5_Uptodate bit happens to be set, R5_Discard again
won't be cleared.  But R5_Uptodate really should be clear at this point.

So make sure R5_Discard is cleared in all cases, and clear
R5_Uptodate when a 'discard' completes.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-22 09:14:13 +11:00
NeilBrown
ef5b7c69b7 md/raid5: move resolving of reconstruct_state earlier in
stripe_handle.

The chunk of code in stripe_handle which responds to a
*_result value in reconstruct_state is really the completion
of some processing that happened outside of handle_stripe
(possibly asynchronously) and so should be one of the first
things done in handle_stripe().

After the next patch it will be important that it happens before
handle_stripe_clean_event(), as that will clear some dev->flags
bit that this code tests.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-22 09:14:09 +11:00
NeilBrown
4ac6875eeb md/raid5: round discard alignment up to power of 2.
blkdev_issue_discard currently assumes that the granularity
is a power of 2.  So in raid5, round the chosen number up to
avoid embarrassment.

Cc: Shaohua Li <shli@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-20 19:42:56 +11:00
NeilBrown
5eff3c439d md: make sure everything is freed when dm-raid stops an array.
md_stop() would stop an array, but not free various attached
data structures.
For internal arrays, these are freed later in do_md_stop() or
mddev_put(), but they don't apply for dm-raid arrays.
So get md_stop() to free them, and only all it from dm-raid.
For internal arrays we now call __md_stop.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-20 10:27:37 +11:00
majianpeng
35f9ac2dce md: Avoid write invalid address if read_seqretry returned true.
If read_seqretry returned true and bbp was changed, it will write
invalid address which can cause some serious problem.

This bug was introduced by commit v3.0-rc7-130-g2699b67.
So fix is suitable for 3.0.y thru 3.6.y.

Reported-by: zhuwenfeng@kedacom.com
Tested-by: zhuwenfeng@kedacom.com
Cc: stable@vger.kernel.org
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-20 10:27:17 +11:00
majianpeng
ab05613a06 md: Reassigned the parameters if read_seqretry returned true in func md_is_badblock.
This bug was introduced by commit(v3.0-rc7-126-g2230dfe).
So fix is suitable for 3.0.y thru 3.6.y.

Cc: stable@vger.kernel.org
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-11-20 10:27:05 +11:00
Jonathan Brassow
ed30be077e MD RAID10: Fix oops when creating RAID10 arrays via dm-raid.c
Commit 2863b9eb didn't take into account the changes to add TRIM support to
RAID10 (commit 532a2a3fb).  That is, when using dm-raid.c to create the
RAID10 arrays, there is no mddev->gendisk or mddev->queue.  The code added
to support TRIM simply assumes that mddev->queue is available without
checking.  The result is an oops any time dm-raid.c attempts to create a
RAID10 device.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-31 11:42:30 +11:00
NeilBrown
02b898f2f0 md/raid1: Fix assembling of arrays containing Replacements.
setup_conf in raid1.c uses conf->raid_disks before assigning
a value.  It is used when including 'Replacement' devices.

The consequence is that assembling an array which contains a
replacement will misbehave and either not include the replacement, or
not include the device being replaced.

Though this doesn't lead directly to data corruption, it could lead to
reduced data safety.

So use mddev->raid_disks, which is initialised, instead.

Bug was introduced by commit c19d57980b
      md/raid1: recognise replacements when assembling arrays.

in 3.3, so fix is suitable for 3.3.y thru 3.6.y.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-31 11:42:03 +11:00
Masanari Iida
83f0d77a7f md: Fix typo in drivers/md
Correct spelling typo in drivers/md.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-10-29 22:57:50 +01:00
Eric Sandeen
0be1fecd7e md faulty: use disk_stack_limits()
in:
fe86cdce block: do not artificially constrain max_sectors for stacking drivers

max_sectors defaults to UINT_MAX.  md faulty wasn't using
disk_stack_limits(), so inherited this large value as well.
This triggered a bug in XFS when stressed over md_faulty, when
a very large bio_alloc() failed.

That was on an older kernel, and I can't reproduce exactly the
same thing upstream, but I think the fix is appropriate in any
case.

Thanks to Mike Snitzer for pointing out the problem.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-22 10:44:55 +11:00
Linus Torvalds
9db908806b md updates for 3.7
"discard" support, some dm-raid improvements and other assorted
 bits and pieces.
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Merge tag 'md-3.7' of git://neil.brown.name/md

Pull md updates from NeilBrown:
 - "discard" support, some dm-raid improvements and other assorted bits
   and pieces.

* tag 'md-3.7' of git://neil.brown.name/md: (29 commits)
  md: refine reporting of resync/reshape delays.
  md/raid5: be careful not to resize_stripes too big.
  md: make sure manual changes to recovery checkpoint are saved.
  md/raid10: use correct limit variable
  md: writing to sync_action should clear the read-auto state.
  Subject: [PATCH] md:change resync_mismatches to atomic64_t to avoid races
  md/raid5: make sure to_read and to_write never go negative.
  md: When RAID5 is dirty, force reconstruct-write instead of read-modify-write.
  md/raid5: protect debug message against NULL derefernce.
  md/raid5: add some missing locking in handle_failed_stripe.
  MD: raid5 avoid unnecessary zero page for trim
  MD: raid5 trim support
  md/bitmap:Don't use IS_ERR to judge alloc_page().
  md/raid1: Don't release reference to device while handling read error.
  raid: replace list_for_each_continue_rcu with new interface
  add further __init annotations to crypto/xor.c
  DM RAID: Fix for "sync" directive ineffectiveness
  DM RAID: Fix comparison of index and quantity for "rebuild" parameter
  DM RAID: Add rebuild capability for RAID10
  DM RAID: Move 'rebuild' checking code to its own function
  ...
2012-10-13 13:22:01 -07:00
Mikulas Patocka
dba141601d dm: store dm_target_io in bio front_pad
Use the recently-added bio front_pad field to allocate struct dm_target_io.

Prior to this patch, dm_target_io was allocated from a mempool. For each
dm_target_io, there is exactly one bio allocated from a bioset.

This patch merges these two allocations into one allocation: we create a
bioset with front_pad equal to the size of dm_target_io so that every
bio allocated from the bioset has sizeof(struct dm_target_io) bytes
before it. We allocate a bio and use the bytes before the bio as
dm_target_io.

_tio_cache is removed and the tio_pool mempool is now only used for
request-based devices.

This idea was introduced by Kent Overstreet.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: tj@kernel.org
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Bill Pemberton <wfp5p@viridian.itc.virginia.edu>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-10-12 21:02:15 +01:00
Mike Snitzer
4f81a41762 dm thin: move bio_prison code to separate module
The bio prison code will be useful to other future DM targets so
move it to a separate module.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-10-12 21:02:13 +01:00
Mike Snitzer
44feb387f6 dm thin: prepare to separate bio_prison code
The bio prison code will be useful to share with future DM targets.

Prepare to move this code into a separate module, adding a dm prefix
to structures and functions that will be exported.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-10-12 21:02:10 +01:00
Mike Snitzer
28eed34e76 dm thin: support discard with non power of two block size
Support discards when the pool's block size is not a power of 2.
The block layer assumes discard_granularity is a power of 2 (in
blkdev_issue_discard), so we set this to the largest power of 2 that is
a divides into the number of sectors in each block, but never less than
DATA_DEV_BLOCK_SIZE_MIN_SECTORS.

This patch eliminates the "Discard support must be disabled when the
block size is not a power of 2" constraint that was imposed in commit
55f2b8b ("dm thin: support for non power of 2 pool blocksize").  That
commit was incomplete: using a block size that is not a power of 2
shouldn't mean disabling discard support on the device completely.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-10-12 21:02:07 +01:00
Wei Yongjun
0bcf08798e dm persistent data: convert to use le32_add_cpu
Convert cpu_to_le32(le32_to_cpu(E1) + E2) to use le32_add_cpu().

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-10-12 16:59:47 +01:00
Mikulas Patocka
fe5fe90639 dm: use ACCESS_ONCE for sysfs values
Use the ACCESS_ONCE macro in dm-bufio and dm-verity where a variable
can be modified asynchronously (through sysfs) and we want to prevent
compiler optimizations that assume that the variable hasn't changed.
(See Documentation/atomic_ops.txt.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-10-12 16:59:46 +01:00
Wei Yongjun
54499afbb8 dm bufio: use list_move
Use list_move() instead of list_del() + list_add().

spatch with a semantic match was used to find this.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-10-12 16:59:44 +01:00
Wei Yongjun
a71a261f5c dm mpath: fix check for null mpio in end_io fn
The mpio dereference should be moved below the BUG_ON NULL test
in multipath_end_io().

spatch with a semantic match was used to found this.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-10-12 16:59:42 +01:00
NeilBrown
72f36d5972 md: refine reporting of resync/reshape delays.
If 'resync_max' is set to 0 (as is often done when starting a
reshape, so the mdadm can remain in control during a sensitive
period), and if the reshape request is initially delayed because
another array using the same array is resyncing or reshaping etc,
when user-space cannot easily tell when the delay changes from being
due to a conflicting reshape, to being due to resync_max = 0.

So introduce a new state: (curr_resync == 3) to reflect this, make
sure it is visible both via /proc/mdstat and via the "sync_completed"
sysfs attribute, and ensure that the event transition from one delay
state to the other is properly notified.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 14:25:57 +11:00
NeilBrown
e56108d65f md/raid5: be careful not to resize_stripes too big.
When a RAID5 is reshaping, conf->raid_disks is increased
before mddev->delta_disks becomes zero.
This can result in check_reshape calling resize_stripes with a
number that is too large.  This particularly happens
when md_check_recovery calls ->check_reshape().

If we use ->previous_raid_disks, we don't risk this.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 14:24:13 +11:00
NeilBrown
db07d85ef6 md: make sure manual changes to recovery checkpoint are saved.
If you make an array bigger but suppress resync of the new region with
  mdadm --grow /dev/mdX --size=max --assume-clean

then stop the array before anything is written to it, the effect of
the "--assume-clean" is lost and the array will resync the new space
when restarted.
So ensure that we update the metadata in the case.

Reported-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 14:22:17 +11:00
Dan Carpenter
91502f099d md/raid10: use correct limit variable
Clang complains that we are assigning a variable to itself.  This should
be using bad_sectors like the similar earlier check does.

Bug has been present since 3.1-rc1.  It is minor but could
conceivably cause corruption or other bad behaviour.

Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 14:20:58 +11:00
NeilBrown
48c26ddc9f md: writing to sync_action should clear the read-auto state.
In some cases array are started in 'read-auto' state where in
nothing gets written to any device until the array is written
to.  The purpose of this is to make accidental auto-assembly
of the wrong arrays less of a risk, and to allow arrays to be
started to read suspend-to-disk images without actually changing
anything (as might happen if the array were dirty and a
resync seemed necessary).

Explicitly writing the 'sync_action' for a read-auto array currently
doesn't clear the read-auto state, so the sync action doesn't
happen, which can be confusing.

So allow any successful write to sync_action to clear any read-auto
state.

Reported-by: Alexander Kühn <alexander.kuehn@nagilum.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 14:19:39 +11:00
Jianpeng Ma
7f7583d420 Subject: [PATCH] md:change resync_mismatches to atomic64_t to avoid races
Now that multiple threads can handle stripes, it is safer to
use an atomic64_t for resync_mismatches, to avoid update races.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 14:17:59 +11:00
NeilBrown
1ed850f356 md/raid5: make sure to_read and to_write never go negative.
to_read and to_write are part of the result of analysing
a stripe before handling it.
Their use is to avoid some loops and tests if the values are
known to be zero.  Thus it is not a problem if they are a
little bit larger than they should be.

So decrementing them in handle_failed_stripe serves little value, and
due to races it could cause some loops to be skipped incorrectly.

So remove those decrements.

Reported-by: "Jianpeng Ma" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:50:13 +11:00
Alexander Lyakas
a7854487cd md: When RAID5 is dirty, force reconstruct-write instead of read-modify-write.
Signed-off-by: Alex Lyakas <alex@zadarastorage.com>
Suggested-by: Yair Hershko <yair@zadarastorage.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:50:12 +11:00
NeilBrown
b97390aec4 md/raid5: protect debug message against NULL derefernce.
The pr_debug in add_stripe_bio could race with something
changing *bip, so it is best to hold the lock until
after the pr_debug.

Reported-by: "Jianpeng Ma" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:50:12 +11:00
NeilBrown
143c4d0573 md/raid5: add some missing locking in handle_failed_stripe.
We really should hold the stripe_lock while accessing
'toread' else we could race with add_stripe_bio and corrupt
a list.

Reported-by: "Jianpeng Ma" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:50:12 +11:00
Shaohua Li
9e44476851 MD: raid5 avoid unnecessary zero page for trim
We want to avoid zero discarded dev page, because it's useless for discard.
But if we don't zero it, another read/write hit such page in the cache and will
get inconsistent data.

To avoid zero the page, we don't set R5_UPTODATE flag after construction is
done. In this way, discard write request is still issued and finished, but read
will not hit the page. If the stripe gets accessed soon, we need reread the
stripe, but since the chance is low, the reread isn't a big deal.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:49:49 +11:00
Shaohua Li
620125f2bf MD: raid5 trim support
Discard for raid4/5/6 has limitation. If discard request size is
small, we do discard for one disk, but we need calculate parity and
write parity disk.  To correctly calculate parity, zero_after_discard
must be guaranteed. Even it's true, we need do discard for one disk
but write another disks, which makes the parity disks wear out
fast. This doesn't make sense. So an efficient discard for raid4/5/6
should discard all data disks and parity disks, which requires the
write pattern to be (A, A+chunk_size, A+chunk_size*2...). If A's size
is smaller than chunk_size, such pattern is almost impossible in
practice. So in this patch, I only handle the case that A's size
equals to chunk_size. That is discard request should be aligned to
stripe size and its size is multiple of stripe size.

Since we can only handle request with specific alignment and size (or
part of the request fitting stripes), we can't guarantee
zero_after_discard even zero_after_discard is true in low level
drives.

The block layer doesn't send down correctly aligned requests even
correct discard alignment is set, so I must filter out.

For raid4/5/6 parity calculation, if data is 0, parity is 0. So if
zero_after_discard is true for all disks, data is consistent after
discard.  Otherwise, data might be lost. Let's consider a scenario:
discard a stripe, write data to one disk and write parity disk. The
stripe could be still inconsistent till then depending on using data
from other data disks or parity disks to calculate new parity. If the
disk is broken, we can't restore it. So in this patch, we only enable
discard support if all disks have zero_after_discard.

If discard fails in one disk, we face the similar inconsistent issue
above. The patch will make discard follow the same path as normal
write request. If discard fails, a resync will be scheduled to make
the data consistent. This isn't good to have extra writes, but data
consistency is important.

If a subsequent read/write request hits raid5 cache of a discarded
stripe, the discarded dev page should have zero filled, so the data is
consistent. This patch will always zero dev page for discarded request
stripe. This isn't optimal because discard request doesn't need such
payload. Next patch will avoid it.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:49:05 +11:00
Jianpeng Ma
582e2e056a md/bitmap:Don't use IS_ERR to judge alloc_page().
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:45:36 +11:00
NeilBrown
7ad4d4a68a md/raid1: Don't release reference to device while handling read error.
When we get a read error, we arrange for raid1d to handle it.
Currently we release the reference on the device.  This can result
in
   conf->mirrors[read_disk].rdev
being NULL in fix_read_error, if the device happens to get removed
before the read error is handled.

So instead keep the reference until the read error has been fully
handled.

Reported-by: hank <pyu@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:44:30 +11:00
Michael Wang
fd177481b4 raid: replace list_for_each_continue_rcu with new interface
This patch replaces list_for_each_continue_rcu() with
list_for_each_entry_continue_rcu() to save a few lines
of code and allow removing list_for_each_continue_rcu().

Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:43:21 +11:00
Jonathan Brassow
761becff01 DM RAID: Fix for "sync" directive ineffectiveness
There are two table arguments that can be given to a DM RAID target
that control whether the array is forced to (re)synchronize or skip
initialization: "sync" and "nosync".  When "sync" is given, we set
mddev->recovery_cp to 0 in order to cause the device to resynchronize.
This is insufficient if there is a bitmap in use, because the array
will simply look at the bitmap and see that there is no recovery
necessary.

The fix is to skip over the loading of the superblocks when "sync" is
given, causing new superblocks to be written that will force the array
to go through initialization (i.e. synchronization).

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:42:19 +11:00
Jonathan Brassow
7386199c47 DM RAID: Fix comparison of index and quantity for "rebuild" parameter
DM RAID: Fix comparison of index and quantity for "rebuild" parameter

The "rebuild" parameter takes an index argument that starts counting from
zero.  The conditional used to validate the index was using '>' rather than
'>=', leaving the door open for an index value that would be 1 too large.

Reported-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:40:36 +11:00
Jonathan Brassow
4ec1e369af DM RAID: Add rebuild capability for RAID10
DM RAID:  Add code to validate replacement slots for RAID10 arrays

RAID10 can handle 'copies - 1' failures for each mirror group.  This code
ensures the user has provided a valid array - one whose devices specified for
rebuild do not exceed the amount of redundancy available.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:40:24 +11:00
Jonathan Brassow
eb6491236f DM RAID: Move 'rebuild' checking code to its own function
DM RAID:  Move chunk of code to it's own function

The code that checks whether device replacements/rebuilds are possible given
a specific RAID type is moved to it's own function.  It will further expand
when the code to check RAID10 is added.  A separate function makes it easier
to read.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:40:09 +11:00
Jonathan Brassow
2863b9eb44 MD RAID10: Prep for DM RAID10 device replacement capability
MD RAID10:  Fix a couple potential kernel panics if RAID10 is used by dm-raid

When device-mapper uses the RAID10 personality through dm-raid.c, there is no
'gendisk' structure in mddev and some sysfs information is also not populated.

This patch avoids touching those non-existent structures.

Signed-off-by: Jonathan Brassow <jbrassow@rehdat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:38:58 +11:00
NeilBrown
1ca69c4bc4 md: avoid taking the mutex on some ioctls.
Some ioctls don't need to take the mutex and doing so can cause
a delay as it is held during super-block update.
So move those ioctls out of the mutex and rely on rcu locking
to ensure we don't access stale data.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:37:33 +11:00
Shaohua Li
4ed8731d8e MD: change the parameter of md thread
Change the thread parameter, so the thread can carry extra info. Next patch
will use it.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:34:00 +11:00
NeilBrown
57c67df488 md/raid10: submit IO from originating thread instead of md thread.
queuing writes to the md thread means that all requests go through the
one processor which may not be able to keep up with very high request
rates.

So use the plugging infrastructure to submit all requests on unplug.
If a 'schedule' is needed, we fall back on the old approach of handing
the requests to the thread for it to handle.

This is nearly identical to a recent patch which provided similar
functionality to RAID1.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:32:13 +11:00
Shaohua Li
532a2a3fba md: raid 10 supports TRIM
This makes md raid 10 support TRIM.

If one disk supports discard and another not, or one has
discard_zero_data and another not, there could be inconsistent between
data from such disks. But this should not matter, discarded data is
useless. This will add extra copy in rebuild though.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:30:52 +11:00
Shaohua Li
2ff8cc2c6d md: raid 1 supports TRIM
This makes md raid 1 support TRIM.
If one disk supports discard and another not, or one has discard_zero_data and
another not, there could be inconsistent between data from such disks. But this
should not matter, discarded data is useless. This will add extra copy in rebuild
though.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:28:54 +11:00
Shaohua Li
c83057a1f4 md: raid 0 supports TRIM
This makes md raid 0 support TRIM.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:25:44 +11:00
Shaohua Li
f1cad2b68e md: linear supports TRIM
This makes md linear support TRIM.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:08:44 +11:00
Denis Efremov
bc78c57388 md/linear: rcu_dereference outside read-lock section
According to the comment in linear_stop function
rcu_dereference in linear_start and linear_stop functions
occurs under reconfig_mutex. The patch represents this
agreement in code and prevents lockdep complaint.

Found by Linux Driver Verification project (linuxtesting.org)

Signed-off-by: Denis Efremov <yefremov.denis@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-10-11 13:08:02 +11:00
Linus Torvalds
ce40be7a82 Merge branch 'for-3.7/core' of git://git.kernel.dk/linux-block
Pull block IO update from Jens Axboe:
 "Core block IO bits for 3.7.  Not a huge round this time, it contains:

   - First series from Kent cleaning up and generalizing bio allocation
     and freeing.

   - WRITE_SAME support from Martin.

   - Mikulas patches to prevent O_DIRECT crashes when someone changes
     the block size of a device.

   - Make bio_split() work on data-less bio's (like trim/discards).

   - A few other minor fixups."

Fixed up silent semantic mis-merge as per Mikulas Patocka and Andrew
Morton.  It is due to the VM no longer using a prio-tree (see commit
6b2dbba8b6: "mm: replace vma prio_tree with an interval tree").

So make set_blocksize() use mapping_mapped() instead of open-coding the
internal VM knowledge that has changed.

* 'for-3.7/core' of git://git.kernel.dk/linux-block: (26 commits)
  block: makes bio_split support bio without data
  scatterlist: refactor the sg_nents
  scatterlist: add sg_nents
  fs: fix include/percpu-rwsem.h export error
  percpu-rw-semaphore: fix documentation typos
  fs/block_dev.c:1644:5: sparse: symbol 'blkdev_mmap' was not declared
  blockdev: turn a rw semaphore into a percpu rw semaphore
  Fix a crash when block device is read and block size is changed at the same time
  block: fix request_queue->flags initialization
  block: lift the initial queue bypass mode on blk_register_queue() instead of blk_init_allocated_queue()
  block: ioctl to zero block ranges
  block: Make blkdev_issue_zeroout use WRITE SAME
  block: Implement support for WRITE SAME
  block: Consolidate command flag and queue limit checks for merges
  block: Clean up special command handling logic
  block/blk-tag.c: Remove useless kfree
  block: remove the duplicated setting for congestion_threshold
  block: reject invalid queue attribute values
  block: Add bio_clone_bioset(), bio_clone_kmalloc()
  block: Consolidate bio_alloc_bioset(), bio_kmalloc()
  ...
2012-10-11 09:04:23 +09:00
Linus Torvalds
033d9959ed Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue changes from Tejun Heo:
 "This is workqueue updates for v3.7-rc1.  A lot of activities this
  round including considerable API and behavior cleanups.

   * delayed_work combines a timer and a work item.  The handling of the
     timer part has always been a bit clunky leading to confusing
     cancelation API with weird corner-case behaviors.  delayed_work is
     updated to use new IRQ safe timer and cancelation now works as
     expected.

   * Another deficiency of delayed_work was lack of the counterpart of
     mod_timer() which led to cancel+queue combinations or open-coded
     timer+work usages.  mod_delayed_work[_on]() are added.

     These two delayed_work changes make delayed_work provide interface
     and behave like timer which is executed with process context.

   * A work item could be executed concurrently on multiple CPUs, which
     is rather unintuitive and made flush_work() behavior confusing and
     half-broken under certain circumstances.  This problem doesn't
     exist for non-reentrant workqueues.  While non-reentrancy check
     isn't free, the overhead is incurred only when a work item bounces
     across different CPUs and even in simulated pathological scenario
     the overhead isn't too high.

     All workqueues are made non-reentrant.  This removes the
     distinction between flush_[delayed_]work() and
     flush_[delayed_]_work_sync().  The former is now as strong as the
     latter and the specified work item is guaranteed to have finished
     execution of any previous queueing on return.

   * In addition to the various bug fixes, Lai redid and simplified CPU
     hotplug handling significantly.

   * Joonsoo introduced system_highpri_wq and used it during CPU
     hotplug.

  There are two merge commits - one to pull in IRQ safe timer from
  tip/timers/core and the other to pull in CPU hotplug fixes from
  wq/for-3.6-fixes as Lai's hotplug restructuring depended on them."

Fixed a number of trivial conflicts, but the more interesting conflicts
were silent ones where the deprecated interfaces had been used by new
code in the merge window, and thus didn't cause any real data conflicts.

Tejun pointed out a few of them, I fixed a couple more.

* 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits)
  workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending()
  workqueue: use cwq_set_max_active() helper for workqueue_set_max_active()
  workqueue: introduce cwq_set_max_active() helper for thaw_workqueues()
  workqueue: remove @delayed from cwq_dec_nr_in_flight()
  workqueue: fix possible stall on try_to_grab_pending() of a delayed work item
  workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback()
  workqueue: use __cpuinit instead of __devinit for cpu callbacks
  workqueue: rename manager_mutex to assoc_mutex
  workqueue: WORKER_REBIND is no longer necessary for idle rebinding
  workqueue: WORKER_REBIND is no longer necessary for busy rebinding
  workqueue: reimplement idle worker rebinding
  workqueue: deprecate __cancel_delayed_work()
  workqueue: reimplement cancel_delayed_work() using try_to_grab_pending()
  workqueue: use mod_delayed_work() instead of __cancel + queue
  workqueue: use irqsafe timer for delayed_work
  workqueue: clean up delayed_work initializers and add missing one
  workqueue: make deferrable delayed_work initializer names consistent
  workqueue: cosmetic whitespace updates for macro definitions
  workqueue: deprecate system_nrt[_freezable]_wq
  workqueue: deprecate flush[_delayed]_work_sync()
  ...
2012-10-02 09:54:49 -07:00
Linus Torvalds
c3a086e638 A few fixes for problems discovered during the 3.6 cycle.
Of particular note, are fixes to the thin target's discard support,
 which I hope is finally working correctly; and fixes for multipath
 ioctls and device limits when there are no paths.
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Merge tag 'dm-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull dm fixes from Alasdair G Kergon:
 "A few fixes for problems discovered during the 3.6 cycle.

  Of particular note, are fixes to the thin target's discard support,
  which I hope is finally working correctly; and fixes for multipath
  ioctls and device limits when there are no paths."

* tag 'dm-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm verity: fix overflow check
  dm thin: fix discard support for data devices
  dm thin: tidy discard support
  dm: retain table limits when swapping to new table with no devices
  dm table: clear add_random unless all devices have it set
  dm: handle requests beyond end of device instead of using BUG_ON
  dm mpath: only retry ioctl when no paths if queue_if_no_path set
  dm thin: do not set discard_zeroes_data
2012-09-28 10:00:01 -07:00
NeilBrown
80b4812407 md/raid10: fix "enough" function for detecting if array is failed.
The 'enough' function is written to work with 'near' arrays only
in that is implicitly assumes that the offset from one 'group' of
devices to the next is the same as the number of copies.
In reality it is the number of 'near' copies.

So change it to make this number explicit.

This bug makes it possible to run arrays without enough drives
present, which is dangerous.
It is appropriate for an -stable kernel, but will almost certainly
need to be modified for some of them.

Cc: stable@vger.kernel.org
Reported-by: Jakub Husák <jakub@gooseman.cz>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-27 12:35:21 +10:00
Mikulas Patocka
1d55f6bcc0 dm verity: fix overflow check
This patch fixes sector_t overflow checking in dm-verity.

Without this patch, the code checks for overflow only if sector_t is
smaller than long long, not if sector_t and long long have the same size.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26 23:45:48 +01:00
Mike Snitzer
0424caa145 dm thin: fix discard support for data devices
The discard limits that get established for a thin-pool or thin device
may be incompatible with the pool's data device.  Avoid this by checking
the discard limits of the pool's data device.  If an incompatibility is
found then the pool's 'discard passdown' feature is disabled.

Change thin_io_hints to ensure that a thin device always uses the same
queue limits as its pool device.

Introduce requested_pf to track whether or not the table line originally
contained the no_discard_passdown flag and use this directly for table
output.  We prepare the correct setting for discard_passdown directly in
bind_control_target (called from pool_io_hints) and store it in
adjusted_pf rather than waiting until we have access to pool->pf in
pool_preresume.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26 23:45:47 +01:00
Mike Snitzer
9bc142dd75 dm thin: tidy discard support
A little thin discard code refactoring to make the next patch (dm thin:
fix discard support for data devices) more readable.
Pull out a couple of functions (and uses bools instead of unsigned for
features).

No functional changes.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26 23:45:46 +01:00
Mike Snitzer
3ae7065616 dm: retain table limits when swapping to new table with no devices
Add a safety net that will re-use the DM device's existing limits in the
event that DM device has a temporary table that doesn't have any
component devices.  This is to reduce the chance that requests not
respecting the hardware limits will reach the device.

DM recalculates queue limits based only on devices which currently exist
in the table.  This creates a problem in the event all devices are
temporarily removed such as all paths being lost in multipath.  DM will
reset the limits to the maximum permissible, which can then assemble
requests which exceed the limits of the paths when the paths are
restored.  The request will fail the blk_rq_check_limits() test when
sent to a path with lower limits, and will be retried without end by
multipath.  This became a much bigger issue after v3.6 commit fe86cdcef
("block: do not artificially constrain max_sectors for stacking
drivers").

Reported-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26 23:45:45 +01:00
Milan Broz
c3c4555edd dm table: clear add_random unless all devices have it set
Always clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
have it set. Otherwise devices with predictable characteristics may
contribute entropy.

QUEUE_FLAG_ADD_RANDOM specifies whether or not queue IO timings
contribute to the random pool.

For bio-based targets this flag is always 0 because such devices have no
real queue.

For request-based devices this flag was always set to 1 by default.

Now set it according to the flags on underlying devices. If there is at
least one device which should not contribute, set the flag to zero: If a
device, such as fast SSD storage, is not suitable for supplying entropy,
a request-based queue stacked over it will not be either.

Because the checking logic is exactly same as for the rotational flag,
share the iteration function with device_is_nonrot().

Signed-off-by: Milan Broz <mbroz@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26 23:45:43 +01:00
Mike Snitzer
ba1cbad93d dm: handle requests beyond end of device instead of using BUG_ON
The access beyond the end of device BUG_ON that was introduced to
dm_request_fn via commit 29e4013de7 ("dm: implement
REQ_FLUSH/FUA support for request-based dm") was an overly
drastic (but simple) response to this situation.

I have received a report that this BUG_ON was hit and now think
it would be better to use dm_kill_unmapped_request() to fail the clone
and original request with -EIO.

map_request() will assign the valid target returned by
dm_table_find_target to tio->ti.  But when the target
isn't valid tio->ti is never assigned (because map_request isn't
called); so add a check for tio->ti != NULL to dm_done().

Reported-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: stable@vger.kernel.org # v2.6.37+
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26 23:45:42 +01:00
Mike Snitzer
7ba10aa6fb dm mpath: only retry ioctl when no paths if queue_if_no_path set
When there are no paths and multipath receives an ioctl, it waits until
a path becomes available.  This behaviour is incorrect if the
"queue_if_no_path" setting was not specified, as then the ioctl should
be rejected immediately, which this patch now does.

commit 35991652b ("dm mpath: allow ioctls to trigger pg init") should
have checked if queue_if_no_path was configured before queueing IO.

Checking for the queue_if_no_path feature, like is done in map_io(),
allows the following table load to work without blocking in the
multipath_ioctl retry loop:

  echo "0 1024 multipath 0 0 0 0" | dmsetup create mpath_nodevs

Without this fix the multipath_ioctl will block with the following stack
trace:

  blkid           D 0000000000000002     0 23936      1 0x00000000
   ffff8802b89e5cd8 0000000000000082 ffff8802b89e5fd8 0000000000012440
   ffff8802b89e4010 0000000000012440 0000000000012440 0000000000012440
   ffff8802b89e5fd8 0000000000012440 ffff88030c2aab30 ffff880325794040
  Call Trace:
   [<ffffffff814ce099>] schedule+0x29/0x70
   [<ffffffff814cc312>] schedule_timeout+0x182/0x2e0
   [<ffffffff8104dee0>] ? lock_timer_base+0x70/0x70
   [<ffffffff814cc48e>] schedule_timeout_uninterruptible+0x1e/0x20
   [<ffffffff8104f840>] msleep+0x20/0x30
   [<ffffffffa0000839>] multipath_ioctl+0x109/0x170 [dm_multipath]
   [<ffffffffa06bfb9c>] dm_blk_ioctl+0xbc/0xd0 [dm_mod]
   [<ffffffff8122a408>] __blkdev_driver_ioctl+0x28/0x30
   [<ffffffff8122a79e>] blkdev_ioctl+0xce/0x730
   [<ffffffff811970ac>] block_ioctl+0x3c/0x40
   [<ffffffff8117321c>] do_vfs_ioctl+0x8c/0x340
   [<ffffffff81166293>] ? sys_newfstat+0x33/0x40
   [<ffffffff81173571>] sys_ioctl+0xa1/0xb0
   [<ffffffff814d70a9>] system_call_fastpath+0x16/0x1b

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.5+
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26 23:45:41 +01:00
Mike Snitzer
307615a26e dm thin: do not set discard_zeroes_data
The dm thin pool target claims to support the zeroing of discarded
data areas.  This turns out to be incorrect when processing discards
that do not exactly cover a complete number of blocks, so the target
must always set discard_zeroes_data_unsupported.

The thin pool target will zero blocks when they are allocated if the
skip_block_zeroing feature is not specified.  The block layer
may send a discard that only partly covers a block.  If a thin pool
block is partially discarded then there is no guarantee that the
discarded data will get zeroed before it is accessed again.
Due to this, thin devices cannot claim discards will always zero data.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org # 3.4+
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-09-26 23:45:39 +01:00
NeilBrown
cb13ff69d6 md/raid5: add missing spin_lock_init.
commit b17459c050
   raid5: add a per-stripe lock

added a spin_lock to the 'stripe_head' struct.
Unfortunately there are two places where this struct is allocated
but the spin lock was only initialised in one of them.

So add the missing spin_lock_init.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-24 16:27:20 +10:00
Martin K. Petersen
4363ac7c13 block: Implement support for WRITE SAME
The WRITE SAME command supported on some SCSI devices allows the same
block to be efficiently replicated throughout a block range. Only a
single logical block is transferred from the host and the storage device
writes the same data to all blocks described by the I/O.

This patch implements support for WRITE SAME in the block layer. The
blkdev_issue_write_same() function can be used by filesystems and block
drivers to replicate a buffer across a block range. This can be used to
efficiently initialize software RAID devices, etc.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-20 14:31:45 +02:00
NeilBrown
6dafab6b13 md: make sure metadata is updated when spares are activated or removed.
It isn't always necessary to update the metadata when spares are
removed as the presence-or-not of a spare isn't really important to
the integrity of an array.
Also activating a spare doesn't always require updating the metadata
as the update on 'recovery-completed' is usually sufficient.

However the introduction of 'replacement' devices have made these
transitions sometimes more important.  For example the 'Replacement'
flag isn't cleared until the original device is removed, so we need
to ensure a metadata update after that 'spare' is removed.

So set MD_CHANGE_DEVS whenever a spare is activated or removed, to
complement the current situation where it is set when a spare is added
or a device is failed (or a number of other less common situations).

This is suitable for -stable as out-of-data metadata could lead
to data corruption.
This is only relevant for 3.3 and later 9when 'replacement' as
introduced.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-19 12:54:22 +10:00
NeilBrown
e5c86471f9 md/raid5: fix calculate of 'degraded' when a replacement becomes active.
When a replacement device becomes active, we mark the device that it
replaces as 'faulty' so that it can subsequently get removed.
However 'calc_degraded' only pays attention to the primary device, not
the replacement, so the array appears to become degraded, which is
wrong.

So teach 'calc_degraded' to consider any replacement if a primary
device is faulty.

This is suitable for -stable as an incorrect 'degraded' value can
confuse md and could lead to data corruption.
This is only relevant for 3.3 and later.

Cc: stable@vger.kernel.org
Reported-by: Robin Hill <robin@robinhill.me.uk>
Reported-by: John Drescher <drescherjm@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-19 12:52:30 +10:00
NeilBrown
a852d7b8a0 Revert "md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE."
This reverts commit 895e3c5c58.

While this patch seemed like a good idea and did help some workloads,
it hurts other workloads.
Large sequential O_DIRECT writes were faster,
Small random O_DIRECT writes were slower.

Other changes (batching RAID5 writes) have improved the sequential
writes using a different mechanism, so the net result of this patch
is definitely negative.  So revert it.

Reported-by: Shaohua Li <shli@kernel.org>
Tested-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-19 12:48:30 +10:00
Kent Overstreet
bf800ef181 block: Add bio_clone_bioset(), bio_clone_kmalloc()
Previously, there was bio_clone() but it only allocated from the fs bio
set; as a result various users were open coding it and using
__bio_clone().

This changes bio_clone() to become bio_clone_bioset(), and then we add
bio_clone() and bio_clone_kmalloc() as wrappers around it, making use of
the functionality the last patch adedd.

This will also help in a later patch changing how bio cloning works.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
CC: Alasdair Kergon <agk@redhat.com>
CC: Boaz Harrosh <bharrosh@panasas.com>
CC: Jeff Garzik <jeff@garzik.org>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09 10:35:39 +02:00
Kent Overstreet
9481874231 dm: Use bioset's front_pad for dm_rq_clone_bio_info
Previously, dm_rq_clone_bio_info needed to be freed by the bio's
destructor to avoid a memory leak in the blk_rq_prep_clone() error path.
This gets rid of a memory allocation and means we can kill
dm_rq_bio_destructor.

The _rq_bio_info_cache kmem cache is unused now and needs to be deleted,
but due to the way io_pool is used and overloaded this looks not quite
trivial so I'm leaving it for a later patch.

v6: Fix comment on struct dm_rq_clone_bio_info, per Tejun

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Alasdair Kergon <agk@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09 10:35:38 +02:00
Kent Overstreet
1e2a410ff7 block: Ues bi_pool for bio_integrity_alloc()
Now that bios keep track of where they were allocated from,
bio_integrity_alloc_bioset() becomes redundant.

Remove bio_integrity_alloc_bioset() and drop bio_set argument from the
related functions and make them use bio->bi_pool.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09 10:35:38 +02:00
Kent Overstreet
395c72a707 block: Generalized bio pool freeing
With the old code, when you allocate a bio from a bio pool you have to
implement your own destructor that knows how to find the bio pool the
bio was originally allocated from.

This adds a new field to struct bio (bi_pool) and changes
bio_alloc_bioset() to use it. This makes various bio destructors
unnecessary, so they're then deleted.

v6: Explain the temporary if statement in bio_put

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
CC: Alasdair Kergon <agk@redhat.com>
CC: Nicholas Bellinger <nab@linux-iscsi.org>
CC: Lars Ellenberg <lars.ellenberg@linbit.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-09 10:35:38 +02:00
Tejun Heo
43829731dd workqueue: deprecate flush[_delayed]_work_sync()
flush[_delayed]_work_sync() are now spurious.  Mark them deprecated
and convert all users to flush[_delayed]_work().

If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant and the regular flushes guarantee that the work item is
not pending or running on any CPU on return, so there's no reason to
use the sync flushes at all and they're going away.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mattia Dongili <malattia@linux.it>
Cc: Kent Yoder <key@linux.vnet.ibm.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Bryan Wu <bryan.wu@canonical.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Avi Kivity <avi@redhat.com>
2012-08-20 14:51:24 -07:00
NeilBrown
e0ee778528 md/raid10: fix problem with on-stack allocation of r10bio structure.
A 'struct r10bio' has an array of per-copy information at the end.
This array is declared with size [0] and r10bio_pool_alloc allocates
enough extra space to store the per-copy information depending on the
number of copies needed.

So declaring a 'struct r10bio on the stack isn't going to work.  It
won't allocate enough space, and memory corruption will ensue.

So in the two places where this is done, declare a sufficiently large
structure and use that instead.

The two call-sites of this bug were introduced in 3.4 and 3.5
so this is suitable for both those kernels.  The patch will have to
be modified for 3.4 as it only has one bug.

Cc: stable@vger.kernel.org
Reported-by: Ivan Vasilyev <ivan.vasilyev@gmail.com>
Tested-by: Ivan Vasilyev <ivan.vasilyev@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-18 09:51:42 +10:00
NeilBrown
667a5313ec md: Don't truncate size at 4TB for RAID0 and Linear
commit 27a7b260f7
   md: Fix handling for devices from 2TB to 4TB in 0.90 metadata.

changed 0.90 metadata handling to truncated size to 4TB as that is
all that 0.90 can record.
However for RAID0 and Linear, 0.90 doesn't need to record the size, so
this truncation is not needed and causes working arrays to become too small.

So avoid the truncation for RAID0 and Linear

This bug was introduced in 3.1 and is suitable for any stable kernels
from then onwards.
As the offending commit was tagged for 'stable', any stable kernel
that it was applied to should also get this patch.  That includes
at least 2.6.32, 2.6.33 and 3.0. (Thanks to Ben Hutchings for
providing that list).

Cc: stable@vger.kernel.org
Signed-off-by: Neil Brown <neilb@suse.de>
2012-08-16 16:46:12 +10:00
Linus Torvalds
25aa6a7ae4 Additional md update for 3.6
This contains a few patches that depend on
 plugging changes in the block layer so needs to wait
 for those.
 It also contains a Kconfig fix for the new RAID10 support
 in dm-raid.
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Merge tag 'md-3.6' of git://neil.brown.name/md

Pull additional md update from NeilBrown:
 "This contains a few patches that depend on plugging changes in the
  block layer so needed to wait for those.

  It also contains a Kconfig fix for the new RAID10 support in dm-raid."

* tag 'md-3.6' of git://neil.brown.name/md:
  md/dm-raid: DM_RAID should select MD_RAID10
  md/raid1: submit IO from originating thread instead of md thread.
  raid5: raid5d handle stripe in batch way
  raid5: make_request use batch stripe release
2012-08-02 11:34:40 -07:00
NeilBrown
d9f691c365 md/dm-raid: DM_RAID should select MD_RAID10
Now that DM_RAID supports raid10, it needs to select that code
to ensure it is included.

Cc: Jonathan Brassow <jbrassow@redhat.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-02 08:35:43 +10:00
NeilBrown
f54a9d0e59 md/raid1: submit IO from originating thread instead of md thread.
queuing writes to the md thread means that all requests go through the
one processor which may not be able to keep up with very high request
rates.

So use the plugging infrastructure to submit all requests on unplug.
If a 'schedule' is needed, we fall back on the old approach of handing
the requests to the thread for it to handle.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-02 08:33:20 +10:00
Shaohua Li
46a06401f6 raid5: raid5d handle stripe in batch way
Let raid5d handle stripe in batch way to reduce conf->device_lock locking.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-02 08:33:15 +10:00
Shaohua Li
8811b5968f raid5: make_request use batch stripe release
make_request() does stripe release for every stripe and the stripe usually has
count 1, which makes previous release_stripe() optimization not work. In my
test, this release_stripe() becomes the heaviest pleace to take
conf->device_lock after previous patches applied.

Below patch makes stripe release batch. All the stripes will be released in
unplug. The STRIPE_ON_UNPLUG_LIST bit is to protect concurrent access stripe
lru.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-02 08:33:00 +10:00
Linus Torvalds
eff0d13f38 Merge branch 'for-3.6/drivers' of git://git.kernel.dk/linux-block
Pull block driver changes from Jens Axboe:

 - Making the plugging support for drivers a bit more sane from Neil.
   This supersedes the plugging change from Shaohua as well.

 - The usual round of drbd updates.

 - Using a tail add instead of a head add in the request completion for
   ndb, making us find the most completed request more quickly.

 - A few floppy changes, getting rid of a duplicated flag and also
   running the floppy init async (since it takes forever in boot terms)
   from Andi.

* 'for-3.6/drivers' of git://git.kernel.dk/linux-block:
  floppy: remove duplicated flag FD_RAW_NEED_DISK
  blk: pass from_schedule to non-request unplug functions.
  block: stack unplug
  blk: centralize non-request unplug handling.
  md: remove plug_cnt feature of plugging.
  block/nbd: micro-optimization in nbd request completion
  drbd: announce FLUSH/FUA capability to upper layers
  drbd: fix max_bio_size to be unsigned
  drbd: flush drbd work queue before invalidate/invalidate remote
  drbd: fix potential access after free
  drbd: call local-io-error handler early
  drbd: do not reset rs_pending_cnt too early
  drbd: reset congestion information before reporting it in /proc/drbd
  drbd: report congestion if we are waiting for some userland callback
  drbd: differentiate between normal and forced detach
  drbd: cleanup, remove two unused global flags
  floppy: Run floppy initialization asynchronous
2012-08-01 09:06:47 -07:00
Linus Torvalds
fcff06c438 Merge branch 'for-next' of git://neil.brown.name/md
Pull md updates from NeilBrown.

* 'for-next' of git://neil.brown.name/md:
  DM RAID: Add support for MD RAID10
  md/RAID1: Add missing case for attempting to repair known bad blocks.
  md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE.
  md/raid1: don't abort a resync on the first badblock.
  md: remove duplicated test on ->openers when calling do_md_stop()
  raid5: Add R5_ReadNoMerge flag which prevent bio from merging at block layer
  md/raid1: prevent merging too large request
  md/raid1: read balance chooses idlest disk for SSD
  md/raid1: make sequential read detection per disk based
  MD RAID10: Export md_raid10_congested
  MD: Move macros from raid1*.h to raid1*.c
  MD RAID1: rename mirror_info structure
  MD RAID10: rename mirror_info structure
  MD RAID10: Fix compiler warning.
  raid5: add a per-stripe lock
  raid5: remove unnecessary bitmap write optimization
  raid5: lockless access raid5 overrided bi_phys_segments
  raid5: reduce chance release_stripe() taking device_lock
2012-08-01 09:02:01 -07:00
Jonathan Brassow
63f33b8dda DM RAID: Add support for MD RAID10
Support the MD RAID10 personality through dm-raid.c

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-08-01 20:41:20 +10:00
NeilBrown
bb181e2e48 Merge commit 'c039c332f23e794deb6d6f37b9f07ff3b27fb2cf' into md
Pull in pre-requisites for adding raid10 support to dm-raid.
2012-08-01 20:40:02 +10:00
NeilBrown
74018dc306 blk: pass from_schedule to non-request unplug functions.
This will allow md/raid to know why the unplug was called,
and will be able to act according - if !from_schedule it
is safe to perform tasks which could themselves schedule.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-07-31 09:08:15 +02:00
NeilBrown
9cbb175088 blk: centralize non-request unplug handling.
Both md and umem has similar code for getting notified on an
blk_finish_plug event.
Centralize this code in block/ and allow each driver to
provide its distinctive difference.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-07-31 09:08:14 +02:00
NeilBrown
0021b7bc04 md: remove plug_cnt feature of plugging.
This seemed like a good idea at the time, but after further thought I
cannot see it making a difference other than very occasionally and
testing to try to exercise the case it is most likely to help did not
show any performance difference by removing it.

So remove the counting of active plugs and allow 'pending writes' to
be activated at any time, not just when no plugs are active.

This is only relevant when there is a write-intent bitmap, and the
updating of the bitmap will likely introduce enough delay that
the single-threading of bitmap updates will be enough to collect large
numbers of updates together.

Removing this will make it easier to centralise the unplug code, and
will clear the other for other unplug enhancements which have a
measurable effect.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-07-31 09:08:14 +02:00
Alexander Lyakas
d57368afe6 md/RAID1: Add missing case for attempting to repair known bad blocks.
When doing resync or repair, attempt to correct bad blocks, according
to WriteErrorSeen policy

Signed-off-by: Alex Lyakas <alex.bolshoy@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 12:01:29 +10:00
Linus Torvalds
27c1ee3f92 Merge branch 'akpm' (Andrew's patch-bomb)
Merge Andrew's first set of patches:
 "Non-MM patches:

   - lots of misc bits

   - tree-wide have_clk() cleanups

   - quite a lot of printk tweaks.  I draw your attention to "printk:
     convert the format for KERN_<LEVEL> to a 2 byte pattern" which
     looks a bit scary.  But afaict it's solid.

   - backlight updates

   - lib/ feature work (notably the addition and use of memweight())

   - checkpatch updates

   - rtc updates

   - nilfs updates

   - fatfs updates (partial, still waiting for acks)

   - kdump, proc, fork, IPC, sysctl, taskstats, pps, etc

   - new fault-injection feature work"

* Merge emailed patches from Andrew Morton <akpm@linux-foundation.org>: (128 commits)
  drivers/misc/lkdtm.c: fix missing allocation failure check
  lib/scatterlist: do not re-write gfp_flags in __sg_alloc_table()
  fault-injection: add tool to run command with failslab or fail_page_alloc
  fault-injection: add selftests for cpu and memory hotplug
  powerpc: pSeries reconfig notifier error injection module
  memory: memory notifier error injection module
  PM: PM notifier error injection module
  cpu: rewrite cpu-notifier-error-inject module
  fault-injection: notifier error injection
  c/r: fcntl: add F_GETOWNER_UIDS option
  resource: make sure requested range is included in the root range
  include/linux/aio.h: cpp->C conversions
  fs: cachefiles: add support for large files in filesystem caching
  pps: return PTR_ERR on error in device_create
  taskstats: check nla_reserve() return
  sysctl: suppress kmemleak messages
  ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION
  ipc: compat: use signed size_t types for msgsnd and msgrcv
  ipc: allow compat IPC version field parsing if !ARCH_WANT_OLD_COMPAT_IPC
  ipc: add COMPAT_SHMLBA support
  ...
2012-07-30 17:25:34 -07:00
Akinobu Mita
8fb980e35b dm: use memweight()
Use memweight() to count the total number of bits set in memory area.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:16 -07:00
majianpeng
895e3c5c58 md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE.
'sync' writes set both REQ_SYNC and REQ_NOIDLE.
O_DIRECT writes set REQ_SYNC but not REQ_NOIDLE.

We currently assume that a REQ_SYNC request will not be followed by
more requests and so set STRIPE_PREREAD_ACTIVE to expedite the
request.
This is appropriate for sync requests, but not for O_DIRECT requests.

So make the setting of STRIPE_PREREAD_ACTIVE conditional on REQ_NOIDLE
rather than REQ_SYNC.  This is consistent with the documented meaning
of REQ_NOIDLE:

        __REQ_NOIDLE,           /* don't anticipate more IO after this one */

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:05:44 +10:00
NeilBrown
b7219ccb33 md/raid1: don't abort a resync on the first badblock.
If a resync of a RAID1 array with 2 devices finds a known bad block
one device it will neither read from, or write to, that device for
this block offset.
So there will be one read_target (The other device) and zero write
targets.
This condition causes md/raid1 to abort the resync assuming that it
has finished - without known bad blocks this would be true.

When there are no write targets because of the presence of bad blocks
we should only skip over the area covered by the bad block.
RAID10 already gets this right, raid1 doesn't.  Or didn't.

As this can cause a 'sync' to abort early and appear to have succeeded
it could lead to some data corruption, so it suitable for -stable.

Cc: stable@vger.kernel.org
Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:05:34 +10:00
NeilBrown
90cf195d9b md: remove duplicated test on ->openers when calling do_md_stop()
do_md_stop tests mddev->openers while holding ->open_mutex,
and fails if this count is too high.
So callers do not need to check mddev->openers and doing so isn't
very meaningful as they don't hold ->open_mutex so the number could
change.

So remove the unnecessary tests on mddev->openers.
These are not called often enough for there to be any gain in
an early test on ->open_mutex to avoid the need for a slightly more
costly mutex_lock call.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:04:55 +10:00
majianpeng
3f9e7c140e raid5: Add R5_ReadNoMerge flag which prevent bio from merging at block layer
Because bios will merge at block-layer,so bios-error may caused by other
bio which be merged into to the same request.
Using this flag,it will find exactly error-sector and not do redundant
operation like re-write and re-read.

V0->V1:Using REQ_FLUSH instead REQ_NOMERGE avoid bio merging at block
layer.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:04:21 +10:00
Shaohua Li
12cee5a8a2 md/raid1: prevent merging too large request
For SSD, if request size exceeds specific value (optimal io size), request size
isn't important for bandwidth. In such condition, if making request size bigger
will cause some disks idle, the total throughput will actually drop. A good
example is doing a readahead in a two-disk raid1 setup.

So when should we split big requests? We absolutly don't want to split big
request to very small requests. Even in SSD, big request transfer is more
efficient. This patch only considers request with size above optimal io size.

If all disks are busy, is it worth doing a split? Say optimal io size is 16k,
two requests 32k and two disks. We can let each disk run one 32k request, or
split the requests to 4 16k requests and each disk runs two. It's hard to say
which case is better, depending on hardware.

So only consider case where there are idle disks. For readahead, split is
always better in this case. And in my test, below patch can improve > 30%
thoughput. Hmm, not 100%, because disk isn't 100% busy.

Such case can happen not just in readahead, for example, in directio. But I
suppose directio usually will have bigger IO depth and make all disks busy, so
I ignored it.

Note: if the raid uses any hard disk, we don't prevent merging. That will make
performace worse.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:03:53 +10:00
Shaohua Li
9dedf60313 md/raid1: read balance chooses idlest disk for SSD
SSD hasn't spindle, distance between requests means nothing. And the original
distance based algorithm sometimes can cause severe performance issue for SSD
raid.

Considering two thread groups, one accesses file A, the other access file B.
The first group will access one disk and the second will access the other disk,
because requests are near from one group and far between groups. In this case,
read balance might keep one disk very busy but the other relative idle.  For
SSD, we should try best to distribute requests to as many disks as possible.
There isn't spindle move penality anyway.

With below patch, I can see more than 50% throughput improvement sometimes
depending on workloads.

The only exception is small requests can be merged to a big request which
typically can drive higher throughput for SSD too. Such small requests are
sequential reads. Unlike hard disk, sequential read which can't be merged (for
example direct IO, or read without readahead) can be ignored for SSD. Again
there is no spindle move penality. readahead dispatches small requests and such
requests can be merged.

Last patch can help detect sequential read well, at least if concurrent read
number isn't greater than raid disk number. In that case, distance based
algorithm doesn't work well too.

V2: For hard disk and SSD mixed raid, doesn't use distance based algorithm for
random IO too. This makes the algorithm generic for raid with SSD.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:03:53 +10:00
Shaohua Li
be4d3280b1 md/raid1: make sequential read detection per disk based
Currently the sequential read detection is global wide. It's natural to make it
per disk based, which can improve the detection for concurrent multiple
sequential reads. And next patch will make SSD read balance not use distance
based algorithm, where this change help detect truly sequential read for SSD.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:03:53 +10:00
Jonathan Brassow
cc4d1efdd0 MD RAID10: Export md_raid10_congested
md/raid10: Export is_congested test.

In similar fashion to commits
	11d8a6e371
	1ed7242e59
we export the RAID10 congestion checking function so that dm-raid.c can
make use of it and make use of the personality.  The 'queue' and 'gendisk'
structures will not be available to the MD code when device-mapper sets
up the device, so we conditionalize access to these fields also.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:03:53 +10:00
Jonathan Brassow
473e87ce48 MD: Move macros from raid1*.h to raid1*.c
MD RAID1/RAID10: Move some macros from .h file to .c file

There are three macros (IO_BLOCKED,IO_MADE_GOOD,BIO_SPECIAL) which are defined
in both raid1.h and raid10.h.  They are only used in there respective .c files.
However, if we wish to make RAID10 accessible to the device-mapper RAID
target (dm-raid.c), then we need to move these macros into the .c files where
they are used so that they do not conflict with each other.

The macros from the two files are identical and could be moved into md.h, but
I chose to leave the duplication and have them remain in the personality
files.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:03:52 +10:00
Jonathan Brassow
0eaf822cb3 MD RAID1: rename mirror_info structure
MD RAID1: Rename the structure 'mirror_info' to 'raid1_info'

The same structure name ('mirror_info') is used by raid10.  Each of these
structures are defined in there respective header files.  If dm-raid is
to support both RAID1 and RAID10, the header files will be included and
the structure names must not collide.  While only one of these structure
names needs to change, this patch adds consistency to the naming of the
structure.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:03:52 +10:00
Jonathan Brassow
dc280d987f MD RAID10: rename mirror_info structure
MD RAID10: Rename the structure 'mirror_info' to 'raid10_info'

The same structure name ('mirror_info') is used by raid1.  Each of these
structures are defined in there respective header files.  If dm-raid is
to support both RAID1 and RAID10, the header files will be included and
the structure names must not collide.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:03:52 +10:00
Jonathan Brassow
3bbae04b12 MD RAID10: Fix compiler warning.
MD RAID10:  Fix compiler warning.

Initialize variable to prevent compiler warning.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-31 10:03:52 +10:00
Alasdair G Kergon
1f4e0ff079 dm thin: commit before gathering status
Commit outstanding metadata before returning the status for a dm thin
pool so that the numbers reported are as up-to-date as possible.

The commit is not performed if the device is suspended or if
the DM_NOFLUSH_FLAG is supplied by userspace and passed to the target
through a new 'status_flags' parameter in the target's dm_status_fn.

The userspace dmsetup tool will support the --noflush flag with the
'dmsetup status' and 'dmsetup wait' commands from version 1.02.76
onwards.

Tested-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:16 +01:00
Joe Thornber
e49e582965 dm thin: add read only and fail io modes
Add read-only and fail-io modes to thin provisioning.

If a transaction commit fails the pool's metadata device will transition
to "read-only" mode.  If a commit fails once already in read-only mode
the transition to "fail-io" mode occurs.

Once in fail-io mode the pool and all associated thin devices will
report a status of "Fail".

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:16 +01:00
Joe Thornber
da105ed5fd dm thin metadata: introduce dm_pool_abort_metadata
Introduce dm_pool_abort_metadata to abort the current metadata
transaction.  Generally this will only be called when bad things are
happening and dm-thin is trying to roll back to a good state for
read-only mode.

It's complicated by the fact that the metadata device may have failed
completely causing the abort to be unable to read the old transaction.
In this case the metadata object is placed in a 'fail' mode and
everything fails apart from destroying it.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:15 +01:00
Joe Thornber
12ba58af46 dm thin metadata: introduce dm_pool_metadata_set_read_only
Introduce dm_pool_metadata_set_read_only to put the underlying block
manager into read-only mode.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:15 +01:00
Joe Thornber
310975573b dm persistent data: introduce dm_bm_set_read_only
Introduce dm_bm_set_read_only to switch the block manager into a
read-only mode.  To be used when dm-thin degrades due to io errors on
the metadata device.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:15 +01:00
Joe Thornber
4afdd680f7 dm thin: reduce number of metadata commits
Reduce the number of metadata commits by using
dm_thin_changed_this_transaction to check if metadata was changed on a
per thin device granularity.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:14 +01:00
Joe Thornber
40db5a5376 dm thin metadata: add dm_thin_changed_this_transaction
Introduce dm_thin_changed_this_transaction to dm-thin-metadata to publish a
useful bit of information we're already tracking.  This will help dm thin
decide when to commit.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:14 +01:00
Joe Thornber
66b1edc05e dm thin metadata: add format option to dm_pool_metadata_open
Add a parameter to dm_pool_metadata_open to indicate whether or not an
unformatted metadata area should be formatted.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:14 +01:00
Joe Thornber
0fa5b17b08 dm thin metadata: tidy up open and format error paths
Tidy up error path in __open_metadata and __format_metadata in dm-thin-metadata.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:14 +01:00
Mike Snitzer
d73ec52538 dm thin metadata: only check incompat features on open
Factor out __check_incompat_features and only call it once when we open
the metadata device rather than at the beginning of every transaction.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:13 +01:00
Joe Thornber
b793995108 dm thin metadata: remove duplicate pmd initialisation
Remove some duplicate initialisation of struct dm_pool_metadata.

These pmd fields are initialised by both:
  __format_metadata's calls to dm_btree_empty
  __write_initial_superblock + __begin_transaction

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:13 +01:00
Joe Thornber
8801e06945 dm thin metadata: remove create parameter from __create_persistent_data_objects
Remove 'create' parameter from __create_persistent_data_objects() in dm-thin-metadata.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:13 +01:00
Joe Thornber
237074c0a3 dm thin metadata: move __superblock_all_zeroes to __open_or_format_metadata
Move the check for __superblock_all_zeroes from
__create_persistent_data_objects() down to __open_or_format_metadata in
dm-thin-metadata.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:13 +01:00
Joe Thornber
a97e5e6fd0 dm thin metadata: remove nr_blocks arg from __create_persistent_data_objects
Remove nr_blocks arg from __create_persistent_data_objects in dm-thin-metadata.
It was always passed as zero.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:12 +01:00
Joe Thornber
e4d2205cdf dm thin metadata: split __open or format metadata
Split __open_or_format_metadata into __format_metadata and __open_metadata in
dm-thin-metadata.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:12 +01:00
Joe Thornber
d6332814e3 dm thin metadata: use struct dm_pool_metadata members in __open_or_format_metadata
Clean up __open_or_format_metadata in dm-thin-metadata by using struct
dm_pool_metadata members to replace local variables.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:12 +01:00
Joe Thornber
583ceee2ed dm thin metadata: zero unused superblock uuid
Zero the unused uuid when initialising the metadata superblock.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:11 +01:00
Joe Thornber
270938bac5 dm thin metadata: lift __begin_transaction out of __write_initial_superblock
Lift the call to __begin_transaction out of __write_initial_superblock in
dm-thin-metadata.  Called higher up the call chain now.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:11 +01:00
Joe Thornber
10d2a9ff7c dm thin metadata: move dm_commit_pool_metadata into __write_initial_superblock
Move dm_commit_pool_metadata inline into __write_initial_superblock in dm-thin-metadata.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:11 +01:00
Joe Thornber
9cb6653f9a dm thin metadata: factor out __write_initial_superblock
Factor out __write_initial_superblock and also pull some other initial
creation code out of dm_pool_metadata_open.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:10 +01:00
Joe Thornber
6a0ebd31b6 dm thin metadata: lift some initialisation out of __open_or_format_metadata
Lift some initialisation out of __open_or_format_metadata in dm-thin-metadata.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:10 +01:00
Joe Thornber
f9dd9352b9 dm thin metadata: factor __destroy_persistent_data out of dm_pool_metadata_close
Factor __destroy_persistent_data_objects out of dm_pool_metadata_close.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:10 +01:00
Joe Thornber
332627db00 dm thin metadata: move bm creation code into create_persistent_data_objects
Move block manager creation and the check for unformatted metadata into
__create_persistent_data_objects().

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:10 +01:00
Joe Thornber
77f49a4027 dm thin metadata: rename init_pmd to __create_persistent_data_objects
Rename init_pmd to __create_persistent_data_objects in dm-thin-metadata.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:10 +01:00
Joe Thornber
2597119206 dm thin metadata: wrap superblock locking
Introduce wrappers to handle write locking the superblock
appropriately.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:09 +01:00
Joe Thornber
3c9ad9bd87 dm persistent data: stop using dm_bm_unlock_move when shadowing blocks in tm
Stop using dm_bm_unlock_move when shadowing blocks in the transaction
manager as an optimisation and remove the function as it is then no
longer used.

Some code, such as the space maps, keeps using on-disk data structures
from the previous transaction.  It can do this because blocks won't
be reallocated until the subsequent transaction.  Using
dm_bm_unlock_move to copy blocks sounds like a win, but it forces a
synchronous read should the old block be accessed.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:09 +01:00
Joe Thornber
384ef0e62e dm persistent data: tidy transaction manager creation fns
Tidy the transaction manager creation functions.

They no longer lock the superblock.  Superblock locking is pulled out to
the caller.

Also export dm_bm_write_lock_zero.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:09 +01:00
Joe Thornber
eb04cf634f dm thin metadata: stop tracking need for commit
Remove an optimisation that tracks whether or not a thin metadata commit
is needed.

If dm_pool_commit_metadata() is called and no changes have been made
to the metadata then this optimisation avoided writing to disk.

Removing because we're going to do something better later.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:08 +01:00
Joe Thornber
51a0f659c0 dm persistent data: create new dm_block_manager struct
This patch introduces a separate struct for the block_manager.
It also uses IS_ERR to check the return value of dm_bufio_client_create
instead of testing incorrectly for NULL.

Prior to this patch a struct dm_block_manager was really an alias for
a struct dm_bufio_client.  We want to add some functionality to the
block manager that will require extra fields, so this one to one
mapping is no longer valid.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:08 +01:00
Joe Thornber
41675aea32 dm thin metadata: factor __setup_btree_details out of init_pmd
Factor __setup_btree_details out of init_pmd in dm-thin-metadata.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:08 +01:00
Alasdair G Kergon
0ac55489d9 dm: use bool bitfields in struct dm_target
Use boolean bit fields for flags in struct dm_target.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:08 +01:00
Joe Thornber
16ad3d103d dm thin: set flush_supported
The thin provisioning target commits internal metadata on flush.  So it
should receive flushes regardless of whether the underlying devices
support them.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:07 +01:00
Joe Thornber
0e9c24ed74 dm: allow targets to request flushes regardless of underlying device support
Allow targets to override the 'supports flush' calculation.

Set 'flush_supported' if a target needs to receive flushes regardless of
whether or not its underlying devices have support.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:07 +01:00
Joe Thornber
f4b90369d3 dm persistent data: only commit space map if index changed
Introduce bitmap_index_changed to track whether or not the index changed
then only commit a space map if it did.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:06 +01:00
Joe Thornber
8d44c98aac dm persistent data: always unlock superblock in dm_bm_flush_and_unlock
Unlock the superblock even if initial dm_bufio_write_dirty_buffers fails.

Also, remove redundant flush calls.  dm_bm_flush_and_unlock's calls to
dm_bufio_write_dirty_buffers already result in dm_bufio_issue_flush
being called.

This avoids warnings about unflushed dirty buffers from bufio.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:06 +01:00
Joe Thornber
6004970136 dm thin: avoid unnecessarily breaking sharing for flushes
There's no need to break sharing, triggering a copy, for a write that has no
data (i.e. a flush).

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:06 +01:00
Joe Thornber
905386f82d dm thin: fix memory leak in process_prepared_mapping error paths
Fix memory leak in process_prepared_mapping by always freeing
the dm_thin_new_mapping structs from the mapping_pool mempool on
the error paths.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:05 +01:00
Mikulas Patocka
c66029f4d4 dm crypt: rename struct convert_context sector field
Rename sector to cc_sector in dm-crypt's convert_context struct.

This is preparation for a future patch that merges dm_io and
convert_context which both have a "sector" field.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:05 +01:00
Alasdair G Kergon
49a8a9204b dm crypt: store crypt_config instead of dm_target struct
Store the crypt_config struct pointer directly in struct dm_crypt_io
instead of the dm_target struct pointer.

Target information is never used - only target->private is referenced,
thus we can change it to point directly to struct crypt_config.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:05 +01:00
Mikulas Patocka
fd2d231faf dm crypt: move cipher data out of per_cpu struct
Move static dm-crypt cipher data out of per-cpu structure.

Cipher information is static, so it does not have to be in a per-cpu
structure.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:05 +01:00
Jonathan E Brassow
c039c332f2 dm raid: move sectors_per_dev calculation
In preparation for RAID10 inclusion in dm-raid, we move the sectors_per_dev
calculation later in the device creation process.  This is because we won't
know up-front how many stripes vs how many mirrors there are which will
change the calculation.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:04 +01:00
Mikulas Patocka
40b6229b69 dm crypt: rename pending field
There are two dm crypt structures that have a field called "pending".

This patch renames them to "cc_pending" and "io_pending" to reduce confusion
and ease searching the code.

Also remove unnecessary initialisation of r in crypt_convert_block().

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:04 +01:00
Jonathan E Brassow
f999e8fe70 dm raid: restructure parse_raid_params
In preparation for RAID10 addition to dm-raid, we change an 'if' conditional
to a 'switch' conditional to make it easier to see what is being checked for
each RAID type.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:04 +01:00
Mike Snitzer
a58a935d5a dm mpath: add retain_attached_hw_handler feature
A SCSI device handler might get attached to a device during the
initial device scan.  We do not necessarily want to override
this when loading a multipath table, so this patch adds a new
multipath feature argument "retain_attached_hw_handler".

During SCSI device scan all loaded SCSI device handlers will be
consulted for a match (via scsi_dh's provided .match).  If a match is
found that device handler will be attached.  We need a way to have
userspace multipathd's provided 'hw_handler' not override the already
attached hardware handler.

When specifying the new feature 'retain_attached_hw_handler' multipath
will use the currently attached hardware handler instead of trying to
attach the one specified during table load.  If no hardware handler is
attached the specified hardware handler will still be used.

Leverages scsi_dh_attach's ability to increment the scsi_dh's reference
count if the same scsi_dh name is provided when attaching - currently
attached scsi_dh name is determined with scsi_dh_attached_handler_name.

Depends upon commit 7e8a74b177
("[SCSI] scsi_dh: add scsi_dh_attached_handler_name").

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Tested-by: Babu Moger <babu.moger@netapp.com>
Reviewed-by: Chandra Seetharaman <sekharan@us.ibm.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:04 +01:00
Mikulas Patocka
f9a8e0cd26 dm thin: optimize power of two block size
dm-thin will be most likely used with a block size that is a power of
two. So it should be optimized for this case.

This patch changes division and modulo operations to shifts and bit
masks if block size is a power of two.

A test that bi_sector is divisible by a block size is removed from
io_overlaps_block. Device mapper never sends bios that span a block
boundary. Consequently, if we tested that bi_size is equivalent to block
size, bi_sector must already be on a block boundary.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:03 +01:00
Mikulas Patocka
4929630901 dm thin: split discards on block boundary
This patch sets the variable "ti->split_discard_requests" for the dm thin
target so that device mapper core splits discard requests on a block
boundary.

Consequently, a discard request that spans multiple blocks is never sent
to dm-thin. The patch also removes some code in process_discard that
deals with discards that span multiple blocks.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:03 +01:00
Mikulas Patocka
7acf0277ce dm: introduce split_discard_requests
This patch introduces a new variable split_discard_requests. It can be
set by targets so that discard requests are split on max_io_len
boundaries.

When split_discard_requests is not set, discard requests are only split on
boundaries between targets, as was the case before this patch.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:03 +01:00
Mike Snitzer
55f2b8bdb0 dm thin: support for non power of 2 pool blocksize
Non power of 2 blocksize support is needed to properly align thinp IO
on storage that has non power of 2 optimal IO sizes (e.g. RAID6 10+2).

Use sector_div to support non power of 2 blocksize for the pool's
data device.  This provides comparable performance to the power of 2
math that was performed until now (as tested on modern x86_64 hardware).

The kernel currently assumes that limits->discard_granularity is a power
of two so the thin target only enables discard support if the block
size is a power of two.

Eliminate pool structure's 'block_shift', 'offset_mask' and
remaining 4 byte holes.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:02 +01:00
Mikulas Patocka
33d07c0dfa dm stripe: optimize chunk_size calculations
dm-stripe is usually used with a chunk size that is a power of two.
Use faster shifts and bit masks in such cases.

stripe_width is already optimized in a similar way.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:02 +01:00
Mikulas Patocka
8f069b41bc dm stripe: remove minimum stripe size
There is no technical limitation in device mapper that would prevent the
dm-stripe target from using a stripe size smaller than page size.

This patch removes the limit and makes stripe volumes portable across
architectures with different page size.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:01 +01:00
Mike Snitzer
eb850de608 dm stripe: support for non power of 2 chunksize
Support non-power-of-2 chunk sizes with dm striping for proper alignment
of stripe IO on storage that has non-power-of-2 optimal IO sizes (e.g.
RAID6 10+2).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:01 +01:00
Mike Snitzer
542f903814 dm: support non power of two target max_io_len
Remove the restriction that limits a target's specified maximum incoming
I/O size to be a power of 2.

Rename this setting from 'split_io' to the less-ambiguous 'max_io_len'.
Change it from sector_t to uint32_t, which is plenty big enough, and
introduce a wrapper function dm_set_target_max_io_len() to set it.
Use sector_div() to process it now that it is not necessarily a power of 2.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:00 +01:00
Mikulas Patocka
1df05483d7 dm stripe: remove stripes_mask
The structure stripe_c contains a stripes_mask field. This field is
useless because it can be trivially calculated by subtracting one from
stripes. It is used only at one place. This patch removes it.

The patch also changes ffs(stripes) - 1 to __ffs(stripes).

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:00 +01:00
Mikulas Patocka
f14fa693c9 dm stripe: fix size test
dm-stripe is supposed to ensure that all the space allocated to the
stripes is fully used and that all stripes are the same size.  This
patch fixes the test.  It checks that device length is divisible by the
chunk size and checks that the resulting quotient is divisible by the
number of stripes (which is equivalent to testing if device length is
divisible by chunk_size * stripes).

Previously, the code only tested that the number of sectors in the target
was divisible by each of the chunk size and the number of stripes
separately, which could leave entire stripes unused.

(A setup that genuinely needs some stripes to be shorter than others
can be created by concatenating striped targets.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:08:00 +01:00
Mike Snitzer
f09996c993 dm thin: provide specific errors for two table load failure cases
Provide specific error message strings for two pool_ctr() failure cases
that currently give just "Unknown error".

Reference: test_two_pools_pointing_to_the_same_metadata_fails and
test_different_pool_cant_replace_pool in thinp-test-suite.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:07:59 +01:00
majianpeng
1a66a08ae8 dm: replace simple_strtoul
Replace obsolete simple_strtoul() with kstrtou8/kstrtouint.

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:07:59 +01:00
Alasdair G Kergon
70c4861102 dm snapshot: remove redundant assignment in merge fn
Remove redundant bvm->bi_sector self-assignment in dm snapshot's
origin_merge().

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:07:59 +01:00
Joe Thornber
8c971178a7 dm thin metadata: introduce THIN_MAX_CONCURRENT_LOCKS
Introduce THIN_MAX_CONCURRENT_LOCKS into dm-thin-metadata to
give a name to an otherwise "magic" number.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:07:58 +01:00
Joe Thornber
d973ac196b dm thin metadata: remove pointless label from __commit_transaction
Remove the pointless label 'out' from __commit_transaction in
dm-thin-metadata.c

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:07:58 +01:00
Joe Thornber
3caf6d73d4 dm persistent data: remove debug space map checker
Remove debug space map checker from dm persistent data.

The space map checker is a wrapper for other space maps that double
checks the reference counts are correct.  It holds all these reference
counts in memory rather than on disk, so uses a lot of memory and is
thus restricted to small pools.

As yet, this checker hasn't found any issues, but has caused a few of
its own due to people turning it on by default with larger pools.

Removing.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:07:58 +01:00
Mike Snitzer
17b7d63f7e dm thin: clean up compiler warning
Clean up "warning: dubious: !x & y".  Also make it clear that
__snapshotted_since() returns a bool and that dm_thin_lookup_result's
'shared' member is a flag.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:07:57 +01:00
Alasdair G Kergon
7768ed33cc dm thin: reduce endio_hook pool size
Reduce the slab size used for the dm_thin_endio_hook mempool.

Allocation has been seen to fail on machines with smaller amounts
of memory due to fragmentation.

  lvm: page allocation failure. order:5, mode:0xd0
  device-mapper: table: 253:38: thin-pool: Error creating pool's endio_hook mempool

Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27 15:07:57 +01:00
Linus Torvalds
935173744a Three fixes for device-mapper discard processing:
- avoid a crash in dm-raid1 when discards coincide with mirror recovery;
   - avoid discarding shared data that's still needed in dm-thin;
   - don't guarantee that discarded blocks will be wiped in dm-raid1.
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Merge tag 'dm-3.5-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull device-mapper discard fixes from Alasdair G Kergon:
  - avoid a crash in dm-raid1 when discards coincide with mirror
    recovery;
  - avoid discarding shared data that's still needed in dm-thin;
  - don't guarantee that discarded blocks will be wiped in dm-raid1.

* tag 'dm-3.5-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm raid1: set discard_zeroes_data_unsupported
  dm thin: do not send discards to shared blocks
  dm raid1: fix crash with mirror recovery and discard
2012-07-20 11:51:22 -07:00
Mikulas Patocka
7c8d3a42fe dm raid1: set discard_zeroes_data_unsupported
We can't guarantee that REQ_DISCARD on dm-mirror zeroes the data even if
the underlying disks support zero on discard.  So this patch sets
ti->discard_zeroes_data_unsupported.

For example, if the mirror is in the process of resynchronizing, it may
happen that kcopyd reads a piece of data, then discard is sent on the
same area and then kcopyd writes the piece of data to another leg.
Consequently, the data is not zeroed.

The flag was made available by commit 983c7db347
(dm crypt: always disable discard_zeroes_data).

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-20 14:25:07 +01:00
Mikulas Patocka
650d2a06b4 dm thin: do not send discards to shared blocks
When process_discard receives a partial discard that doesn't cover a
full block, it sends this discard down to that block. Unfortunately, the
block can be shared and the discard would corrupt the other snapshots
sharing this block.

This patch detects block sharing and ends the discard with success when
sending it to the shared block.

The above change means that if the device supports discard it can't be
guaranteed that a discard request zeroes data. Therefore, we set
ti->discard_zeroes_data_unsupported.

Thin target discard support with this bug arrived in commit
104655fd4d (dm thin: support discards).

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-20 14:25:05 +01:00
Mikulas Patocka
751f188dd5 dm raid1: fix crash with mirror recovery and discard
This patch fixes a crash when a discard request is sent during mirror
recovery.

Firstly, some background.  Generally, the following sequence happens during
mirror synchronization:
- function do_recovery is called
- do_recovery calls dm_rh_recovery_prepare
- dm_rh_recovery_prepare uses a semaphore to limit the number
  simultaneously recovered regions (by default the semaphore value is 1,
  so only one region at a time is recovered)
- dm_rh_recovery_prepare calls __rh_recovery_prepare,
  __rh_recovery_prepare asks the log driver for the next region to
  recover. Then, it sets the region state to DM_RH_RECOVERING. If there
  are no pending I/Os on this region, the region is added to
  quiesced_regions list. If there are pending I/Os, the region is not
  added to any list. It is added to the quiesced_regions list later (by
  dm_rh_dec function) when all I/Os finish.
- when the region is on quiesced_regions list, there are no I/Os in
  flight on this region. The region is popped from the list in
  dm_rh_recovery_start function. Then, a kcopyd job is started in the
  recover function.
- when the kcopyd job finishes, recovery_complete is called. It calls
  dm_rh_recovery_end. dm_rh_recovery_end adds the region to
  recovered_regions or failed_recovered_regions list (depending on
  whether the copy operation was successful or not).

The above mechanism assumes that if the region is in DM_RH_RECOVERING
state, no new I/Os are started on this region. When I/O is started,
dm_rh_inc_pending is called, which increases reg->pending count. When
I/O is finished, dm_rh_dec is called. It decreases reg->pending count.
If the count is zero and the region was in DM_RH_RECOVERING state,
dm_rh_dec adds it to the quiesced_regions list.

Consequently, if we call dm_rh_inc_pending/dm_rh_dec while the region is
in DM_RH_RECOVERING state, it could be added to quiesced_regions list
multiple times or it could be added to this list when kcopyd is copying
data (it is assumed that the region is not on any list while kcopyd does
its jobs). This results in memory corruption and crash.

There already exist bypasses for REQ_FLUSH requests: REQ_FLUSH requests
do not belong to any region, so they are always added to the sync list
in do_writes. dm_rh_inc_pending does not increase count for REQ_FLUSH
requests. In mirror_end_io, dm_rh_dec is never called for REQ_FLUSH
requests. These bypasses avoid the crash possibility described above.

These bypasses were improperly implemented for REQ_DISCARD when
the mirror target gained discard support in commit
5fc2ffeabb (dm raid1: support discard).

In do_writes, REQ_DISCARD requests is always added to the sync queue and
immediately dispatched (even if the region is in DM_RH_RECOVERING).  However,
dm_rh_inc and dm_rh_dec is called for REQ_DISCARD resusts.  So it violates the
rule that no I/Os are started on DM_RH_RECOVERING regions, and causes the list
corruption described above.

This patch changes it so that REQ_DISCARD requests follow the same path
as REQ_FLUSH. This avoids the crash.

Reference: https://bugzilla.redhat.com/837607

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-20 14:25:03 +01:00
Shaohua Li
b17459c050 raid5: add a per-stripe lock
Add a per-stripe lock to protect stripe specific data. The purpose is to reduce
lock contention of conf->device_lock.

stripe ->toread, ->towrite are protected by per-stripe lock.  Accessing bio
list of the stripe is always serialized by this lock, so adding bio to the
lists (add_stripe_bio()) and removing bio from the lists (like
ops_run_biofill()) not race.

If bio in ->read, ->written ... list are not shared by multiple stripes, we
don't need any lock to protect ->read, ->written, because STRIPE_ACTIVE will
protect them. If the bio are shared,  there are two protections:
1. bi_phys_segments acts as a reference count
2. traverse the list uses r5_next_bio, which makes traverse never access bio
not belonging to the stripe

Let's have an example:
|  stripe1 |  stripe2    |  stripe3  |
...bio1......|bio2|bio3|....bio4.....

stripe2 has 4 bios, when it's finished, it will decrement bi_phys_segments for
all bios, but only end_bio for bio2 and bio3. bio1->bi_next still points to
bio2, but this doesn't matter. When stripe1 is finished, it will not touch bio2
because of r5_next_bio check. Next time stripe1 will end_bio for bio1 and
stripe3 will end_bio bio4.

before add_stripe_bio() addes a bio to a stripe, we already increament the bio
bi_phys_segments, so don't worry other stripes release the bio.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-19 16:01:31 +10:00
Shaohua Li
7eaf7e8eb3 raid5: remove unnecessary bitmap write optimization
Neil pointed out the bitmap write optimization in handle_stripe_clean_event()
is unnecessary, because the chance one stripe gets written twice in the mean
time is rare. We can always do a bitmap_startwrite when a write request is
added to a stripe and bitmap_endwrite after write request is done.  Delete the
optimization. With it, we can delete some cases of device_lock.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-19 16:01:31 +10:00
Shaohua Li
e7836bd6f6 raid5: lockless access raid5 overrided bi_phys_segments
Raid5 overrides bio->bi_phys_segments, accessing it is with device_lock hold,
which is unnecessary, We can make it lockless actually.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-19 16:01:31 +10:00
Shaohua Li
4eb788df67 raid5: reduce chance release_stripe() taking device_lock
release_stripe() is a place conf->device_lock is heavily contended. We take the
lock even stripe count isn't 1, which isn't required.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-19 16:01:31 +10:00
NeilBrown
58e94ae184 md/raid1: close some possible races on write errors during resync
commit 4367af5561
   md/raid1: clear bad-block record when write succeeds.

Added a 'reschedule_retry' call possibility at the end of
end_sync_write, but didn't add matching code at the end of
sync_request_write.  So if the writes complete very quickly, or
scheduling makes it seem that way, then we can miss rescheduling
the request and the resync could hang.

Also commit 73d5c38a95
    md: avoid races when stopping resync.

Fix a race condition in this same code in end_sync_write but didn't
make the change in sync_request_write.

This patch updates sync_request_write to fix both of those.
Patch is suitable for 3.1 and later kernels.

Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Original-version-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-19 15:59:18 +10:00
NeilBrown
a05b7ea03d md: avoid crash when stopping md array races with closing other open fds.
md will refuse to stop an array if any other fd (or mounted fs) is
using it.
When any fs is unmounted of when the last open fd is closed all
pending IO will be flushed (e.g. sync_blockdev call in __blkdev_put)
so there will be no pending IO to worry about when the array is
stopped.

However in order to send the STOP_ARRAY ioctl to stop the array one
must first get and open fd on the block device.
If some fd is being used to write to the block device and it is closed
after mdadm open the block device, but before mdadm issues the
STOP_ARRAY ioctl, then there will be no last-close on the md device so
__blkdev_put will not call sync_blockdev.

If this happens, then IO can still be in-flight while md tears down
the array and bad things can happen (use-after-free and subsequent
havoc).

So in the case where do_md_stop is being called from an open file
descriptor, call sync_block after taking the mutex to ensure there
will be no new openers.

This is needed when setting a read-write device to read-only too.

Cc: stable@vger.kernel.org
Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-19 15:59:18 +10:00
NeilBrown
25f7fd470b md: fix bug in handling of new_data_offset
commit c6563a8c38
    md: add possibility to change data-offset for devices.

introduced a 'new_data_offset' attribute which should normally
be the same as 'data_offset', but can be explicitly set to a different
value to allow a reshape operation to move the data.

Unfortunately when the 'data_offset' is explicitly set through
sysfs, the new_data_offset is not also set, so the two would become
out-of-sync incorrectly.

One result of this is that trying to set the 'size' after the
'data_offset' would fail because it is not permitted to set the size
when the 'data_offset' and 'new_data_offset' are different - as that
can be confusing.
Consequently when mdadm tried to do this while assembling an IMSM
array it would fail.

This bug was introduced in 3.5-rc1.

Reported-by: Brian Downing <bdowning@lavos.net>
Bisected-by: Brian Downing <bdowning@lavos.net>
Tested-by: Brian Downing <bdowning@lavos.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-19 15:59:18 +10:00
Linus Torvalds
fdb1335a82 md: One use-after-free bugfix for RAID1
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Merge tag 'md-3.5-fixes' of git://neil.brown.name/md

Pull use-after-free RAID1 bugfix from NeilBrown.

* tag 'md-3.5-fixes' of git://neil.brown.name/md:
  md/raid1: fix use-after-free bug in RAID1 data-check code.
2012-07-13 17:59:33 -07:00
NeilBrown
2d4f4f3384 md/raid1: fix use-after-free bug in RAID1 data-check code.
This bug has been present ever since data-check was introduce
in 2.6.16.  However it would only fire if a data-check were
done on a degraded array, which was only possible if the array
has 3 or more devices.  This is certainly possible, but is quite
uncommon.

Since hot-replace was added in 3.3 it can happen more often as
the same condition can arise if not all possible replacements are
present.

The problem is that as soon as we submit the last read request, the
'r1_bio' structure could be freed at any time, so we really should
stop looking at it.  If the last device is being read from we will
stop looking at it.  However if the last device is not due to be read
from, we will still check the bio pointer in the r1_bio, but the
r1_bio might already be free.

So use the read_targets counter to make sure we stop looking for bios
to submit as soon as we have submitted them all.

This fix is suitable for any -stable kernel since 2.6.16.

Cc: stable@vger.kernel.org
Reported-by: Arnold Schulz <arnysch@gmx.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-09 11:34:13 +10:00
Linus Torvalds
6c8addcb76 md - fix build error in previous patch.
I really shouldn't do important things late in the day.  It seems
 that I get careless.
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Merge tag 'md-3.5-fixes' of git://neil.brown.name/md

Pull raid10 build failure fix from NeilBrown:
 "I really shouldn't do important things late in the day.  It seems that
  I get careless."

* tag 'md-3.5-fixes' of git://neil.brown.name/md:
  md/raid10: fix careless build error
2012-07-03 18:05:35 -07:00
NeilBrown
10684112c9 md/raid10: fix careless build error
build error introduced by commit b357f04a67

That function doesn't get extra args until a later patch.  Bother.

Reported-by: Fengguang Wu <wfg@linux.intel.com> 
Reported-by: Simon Kirby <sim@hostway.ca>
Reported-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-04 09:35:35 +10:00
Linus Torvalds
3492ee7274 Four minor thin provisioning fixes and correct and update dm-verity
documentation.
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Merge tag 'dm-3.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull device-mapper fixes from Alasdair G Kergon:
 "Four minor thin provisioning fixes and correct and update dm-verity
  documentation."

* tag 'dm-3.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm: verity fix documentation
  dm persistent data: fix allocation failure in space map checker init
  dm persistent data: handle space map checker creation failure
  dm persistent data: fix shadow_info_leak on dm_tm_destroy
  dm thin: commit metadata before creating metadata snapshot
2012-07-03 11:08:16 -07:00
Mike Snitzer
b0239faaf8 dm persistent data: fix allocation failure in space map checker init
If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and memory is fragmented and a
sufficiently-large metadata device is used in a thin pool then the space
map checker will fail to allocate the memory it requires.

Switch from kmalloc to vmalloc to allow larger virtually contiguous
allocations for the space map checker's internal count arrays.

Reported-by: Vivek Goyal <vgoyal@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-03 12:55:37 +01:00
Mike Snitzer
62662303e7 dm persistent data: handle space map checker creation failure
If CONFIG_DM_DEBUG_SPACE_MAPS is enabled and dm_sm_checker_create()
fails, dm_tm_create_internal() would still return success even though it
cleaned up all resources it was supposed to have created.  This will
lead to a kernel crash:

general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
...
RIP: 0010:[<ffffffff81593659>]  [<ffffffff81593659>] dm_bufio_get_block_size+0x9/0x20
Call Trace:
  [<ffffffff81599bae>] dm_bm_block_size+0xe/0x10
  [<ffffffff8159b8b8>] sm_ll_init+0x78/0xd0
  [<ffffffff8159c1a6>] sm_ll_new_disk+0x16/0xa0
  [<ffffffff8159c98e>] dm_sm_disk_create+0xfe/0x160
  [<ffffffff815abf6e>] dm_pool_metadata_open+0x16e/0x6a0
  [<ffffffff815aa010>] pool_ctr+0x3f0/0x900
  [<ffffffff8158d565>] dm_table_add_target+0x195/0x450
  [<ffffffff815904c4>] table_load+0xe4/0x330
  [<ffffffff815917ea>] ctl_ioctl+0x15a/0x2c0
  [<ffffffff81591963>] dm_ctl_ioctl+0x13/0x20
  [<ffffffff8116a4f8>] do_vfs_ioctl+0x98/0x560
  [<ffffffff8116aa51>] sys_ioctl+0x91/0xa0
  [<ffffffff81869f52>] system_call_fastpath+0x16/0x1b

Fix the space map checker code to return an appropriate ERR_PTR and have
dm_sm_disk_create() and dm_tm_create_internal() check for it with
IS_ERR.

Reported-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-03 12:55:35 +01:00
Mike Snitzer
25d7cd6faa dm persistent data: fix shadow_info_leak on dm_tm_destroy
Cleanup the shadow table before destroying the transaction manager.

Reference: leak was identified with kmemleak when running
test_discard_random_sectors in the thinp-test-suite.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-03 12:55:33 +01:00
Joe Thornber
0d200aefd4 dm thin: commit metadata before creating metadata snapshot
Userland sometimes sees a corrupt metadata block if metadata is changing
rapidly when a metadata snapshot is reserved for userland,  To make the
problem go away, commit before we take the metadata snapshot (which is a
sensible thing to do anyway).

The checksums mean userland spots this corruption immediately so there's
no risk of acting on incorrect data.  No corruption exists from the
kernel's point of view, and thin_check passes after pool shutdown.

I believe this is to do with shared blocks at the first level of the
{device, mapping} btree.  Prior to the metadata-snap support no sharing
at this level was possible, so this patch is only required after commit
cc8394d86f ("dm thin: provide userspace
access to pool metadata").

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-03 12:55:31 +01:00
NeilBrown
b357f04a67 md: fix up plugging (again).
The value returned by "mddev_check_plug" is only valid until the
next 'schedule' as that will unplug things.  This could happen at any
call to mempool_alloc.
So just calling mddev_check_plug at the start doesn't really make
sense.

So call it just before, or just after, queuing things for the thread.
As the action that happens at unplug is to wake the thread, this makes
lots of sense.
If we cannot add a plug (which requires a small GFP_ATOMIC alloc) we
wake thread immediately.

RAID5 is a bit different.  Requests are queued for the thread and the
thread is woken by release_stripe.  So we don't need to wake the
thread on failure.
However the thread doesn't perform certain actions when there is any
active plug, so it is important to install a plug before waking the
thread.  So for RAID5 we install the plug *before* queuing the request
and waking the thread.

Without this patch it is possible for raid1 or raid10 to queue a
request without then waking the thread, resulting in the array locking
up.

Also change raid10 to only flush_pending_write when there are not
active plugs, just like raid1.

This patch is suitable for 3.0 or later.  I plan to submit it to
-stable, but I'll like to let it spend a few weeks in mainline
first to be sure it is completely safe.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 17:45:31 +10:00
NeilBrown
f456309106 md: support re-add of recovering devices.
We currently only allow a device to be re-added if it appear to be
in-sync.  This is overly restrictive as it may be desirable to re-add
a device that is in the middle of recovery.

So remove the test for "InSync" - the test on rdev->raid_disk is
sufficient to ensure that the re-add will succeed.

Reported-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Tested-by: Alexander Lyakas <alex.bolshoy@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 15:59:06 +10:00
NeilBrown
32644afd89 md/raid1: fix bug in read_balance introduced by hot-replace
When we added hot_replace we doubled the number of devices
that could be in a RAID1 array.  So we doubled how far read_balance
would search.  Unfortunately we didn't double the point at which
it looped back to the beginning - so it effectively loops over
all non-replacement disks twice.
This doesn't cause bad behaviour, but it pointless and means we
never read from replacement devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 15:58:42 +10:00
Shaohua Li
fab363b5ff raid5: delayed stripe fix
There isn't locking setting STRIPE_DELAYED and STRIPE_PREREAD_ACTIVE bits, but
the two bits have relationship. A delayed stripe can be moved to hold list only
when preread active stripe count is below IO_THRESHOLD. If a stripe has both
the bits set, such stripe will be in delayed list and preread count not 0,
which will make such stripe never leave delayed list.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 15:57:19 +10:00
majianpeng
2e8ac30312 md/raid456: When read error cannot be recovered, record bad block
We may not be able to fix a bad block if:
 - the array is degraded
 - the over-write fails.

In these cases we currently eject the device, but we should
record a bad block if possible.

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 15:57:02 +10:00
NeilBrown
0232605d98 md: make 'name' arg to md_register_thread non-optional.
Having the 'name' arg optional and defaulting to the current
personality name is no necessary and leads to errors, as when
changing the level of an array we can end up using the
name of the old level instead of the new one.

So make it non-optional and always explicitly pass the name
of the level that the array will be.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 15:56:52 +10:00
NeilBrown
055d3747db md/raid10: fix failure when trying to repair a read error.
commit 58c54fcca3
     md/raid10: handle further errors during fix_read_error better.

in 3.1 added "r10_sync_page_io" which takes an IO size in sectors.
But we were passing the IO size in bytes!!!
This resulting in bio_add_page failing, and empty request being sent
down, and a consequent BUG_ON in scsi_lib.

[fix missing space in error message at same time]

This fix is suitable for 3.1.y and later.

Cc: stable@vger.kernel.org
Reported-by: Christian Balzer <chibi@gol.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 15:55:33 +10:00
NeilBrown
5f066c632f md/raid5: fix refcount problem when blocked_rdev is set.
commit 43220aa0f2
    md/raid5: fix a hang on device failure.

fixed a hang, but introduced a refcounting in-balance so
that if the presence of bad-blocks ever caused an rdev to
be 'blocked' we would increment the refcount on the rdev and
never decrement it.

So added the needed rdev_dec_pending when md_wait_for_blocked_rdev
is not called.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 12:13:29 +10:00
majianpeng
7c2c57c9a9 md:Add blk_plug in sync_thread.
Add blk_plug in sync_thread will increase the performance of sync.
Because sync_thread did not blk_plug,so when raid sync, the bio merge
not well.

Testing environment:
SATA controller: Intel Corporation 82801JI (ICH10 Family) SATA AHCI
Controller.
OS:Linux xxx 3.5.0-rc2+ #340 SMP Tue Jun 12 09:00:25 CST 2012
x86_64 x86_64 x86_64 GNU/Linux.
RAID5: four ST31000524NS disk.

Without blk_plug:recovery speed about 63M/Sec;
Add blk_plug:recovery speed about 120M/Sec.

Using blktrace:
blktrace -d /dev/sdb -w 60  -o -|blkparse -i -

without blk_plug:
Total (8,16):
 Reads Queued:      309811,     1239MiB	 Writes Queued:           0,        0KiB
 Read Dispatches:   283583,     1189MiB	 Write Dispatches:        0,        0KiB
 Reads Requeued:         0		 Writes Requeued:         0
 Reads Completed:   273351,     1149MiB	 Writes Completed:        0,        0KiB
 Read Merges:        23533,    94132KiB	 Write Merges:            0,        0KiB
 IO unplugs:             0        	 Timer unplugs:           0

add blk_plug:
Total (8,16):
 Reads Queued:      428697,     1714MiB	 Writes Queued:           0,        0KiB
 Read Dispatches:     3954,     1714MiB	 Write Dispatches:        0,        0KiB
 Reads Requeued:         0		 Writes Requeued:         0
 Reads Completed:     3956,     1715MiB	 Writes Completed:        0,        0KiB
 Read Merges:       424743,     1698MiB	 Write Merges:            0,        0KiB
 IO unplugs:             0        	 Timer unplugs:        3384

The ratio of merge will be markedly increased.

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 12:12:26 +10:00
majianpeng
1850753d2e md/raid5: In ops_run_io, inc nr_pending before calling md_wait_for_blocked_rdev
In ops_run_io(), the call to md_wait_for_blocked_rdev will decrement
nr_pending so we lose the reference we hold on the rdev.
So atomic_inc it first to maintain the reference.

This bug was introduced by commit  73e92e51b7
    md/raid5.  Don't write to known bad block on doubtful devices.

which appeared in 3.0, so patch is suitable for stable kernels since
then.

Cc: stable@vger.kernel.org
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 12:11:54 +10:00
majianpeng
6c0544e255 md/raid5: Do not add data_offset before call to is_badblock
In chunk_aligned_read() we are adding data_offset before calling
is_badblock.  But is_badblock also adds data_offset, so that is bad.

So move the addition of data_offset to after the call to
is_badblock.

This bug was introduced by commit 31c176ecdf
     md/raid5: avoid reading from known bad blocks.
which first appeared in 3.0.  So that patch is suitable for any
-stable kernel from 3.0.y onwards.  However it will need minor
revision for most of those (as the comment didn't appear until
recently).

Cc: stable@vger.kernel.org
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 12:09:57 +10:00
NeilBrown
5cfb22a1f8 md/raid5: prefer replacing failed devices over want-replacement devices.
If a RAID5 has both a failed device and a device marked as
'WantReplacement', then we should preferentially replace the failed
device.
However the current code replaces whichever is found first.
So split into 2 loops, check fail failed/missing first, and only check
for WantReplacement if nothing is failed or missing.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 11:46:53 +10:00
NeilBrown
fc448a18ae md/raid10: Don't try to recovery unmatched (and unused) chunks.
If a RAID10 has an odd number of chunks - as might happen when there
are an odd number of devices - the last chunk has no pair and so is
not mirrored.  We don't store data there, but when recovering the last
device in an array we retry to recover that last chunk from a
non-existent location.  This results in an error, and the recovery
aborts.

When we get to that last chunk we should just stop - there is nothing
more to do anyway.

This bug has been present since the introduction of RAID10, so the
patch is appropriate for any -stable kernel.

Cc: stable@vger.kernel.org
Reported-by: Christian Balzer <chibi@gol.com>
Tested-by: Christian Balzer <chibi@gol.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-07-03 10:37:30 +10:00
Linus Torvalds
374916ed16 md: 2 fixes for 3.5-rc
One sparse-warning fix, one bigfix for 3.4-stable
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Merge tag 'md-3.5-fixes' of git://neil.brown.name/md

Pull two md fixes from NeilBrown:
 "One sparse-warning fix, one bugfix for 3.4-stable"

* tag 'md-3.5-fixes' of git://neil.brown.name/md:
  md: raid1/raid10: fix problem with merge_bvec_fn
  lib/raid6: fix sparse warnings in recovery functions
2012-06-06 09:49:28 -07:00
Linus Torvalds
912afc3616 Improve multipath's retrying mechanism in some defined circumstances
and provide a simple reserve/release mechanism for userspace tools to
 access thin provisioning metadata while the pool is in use.
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Merge tag 'dm-3.5-changes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull device-mapper updates from Alasdair G Kergon:
 "Improve multipath's retrying mechanism in some defined circumstances
  and provide a simple reserve/release mechanism for userspace tools to
  access thin provisioning metadata while the pool is in use."

* tag 'dm-3.5-changes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm thin: provide userspace access to pool metadata
  dm thin: use slab mempools
  dm mpath: allow ioctls to trigger pg init
  dm mpath: delay retry of bypassed pg
  dm mpath: reduce size of struct multipath
2012-06-02 17:39:40 -07:00
Joe Thornber
cc8394d86f dm thin: provide userspace access to pool metadata
This patch implements two new messages that can be sent to the thin
pool target allowing it to take a snapshot of the _metadata_.  This,
read-only snapshot can be accessed by userland, concurrently with the
live target.

Only one metadata snapshot can be held at a time.  The pool's status
line will give the block location for the current msnap.

Since version 0.1.5 of the userland thin provisioning tools, the
thin_dump program displays the msnap as follows:

    thin_dump -m <msnap root> <metadata dev>

Available here: https://github.com/jthornber/thin-provisioning-tools

Now that userland can access the metadata we can do various things
that have traditionally been kernel side tasks:

     i) Incremental backups.

     By using metadata snapshots we can work out what blocks have
     changed over time.  Combined with data snapshots we can ensure
     the data doesn't change while we back it up.

     A short proof of concept script can be found here:

     https://github.com/jthornber/thinp-test-suite/blob/master/incremental_backup_example.rb

     ii) Migration of thin devices from one pool to another.

     iii) Merging snapshots back into an external origin.

     iv) Asyncronous replication.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03 00:30:01 +01:00
Mike Snitzer
a24c25696b dm thin: use slab mempools
Use dedicated caches prefixed with a "dm_" name rather than relying on
kmalloc mempools backed by generic slab caches so the memory usage of
thin provisioning (and any leaks) can be accounted for independently.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03 00:30:00 +01:00
Mikulas Patocka
35991652ba dm mpath: allow ioctls to trigger pg init
After the failure of a group of paths, any alternative paths that
need initialising do not become available until further I/O is sent to
the device.  Until this has happened, ioctls return -EAGAIN.

With this patch, new paths are made available in response to an ioctl
too.  The processing of the ioctl gets delayed until this has happened.

Instead of returning an error, we submit a work item to kmultipathd
(that will potentially activate the new path) and retry in ten
milliseconds.

Note that the patch doesn't retry an ioctl if the ioctl itself fails due
to a path failure.  Such retries should be handled intelligently by the
code that generated the ioctl in the first place, noting that some SCSI
commands should not be retried because they are not idempotent (XOR write
commands).  For commands that could be retried, there is a danger that
if the device rejected the SCSI command, the path could be errorneously
marked as failed, and the request would be retried on another path which
might fail too.  It can be determined if the failure happens on the
device or on the SCSI controller, but there is no guarantee that all
SCSI drivers set these flags correctly.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03 00:29:58 +01:00
Mike Christie
f220fd4efb dm mpath: delay retry of bypassed pg
If I/O needs retrying and only bypassed priority groups are available,
set the pg_init_delay_retry flag to wait before retrying.

If, for example, the reason for the bypass is that the controller is
getting reset or there is a firmware upgrade happening, retrying right
away would cause a flood of log messages and retries for what could be a
few seconds or even several minutes.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03 00:29:45 +01:00
Mike Snitzer
1fbdd2b3a3 dm mpath: reduce size of struct multipath
Move multipath structure's 'lock' and 'queue_size' members to eliminate
two 4-byte holes.  Also use a bit within a single unsigned int for each
existing flag (saves 8-bytes).  This allows future flags to be added
without each consuming an unsigned int.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03 00:29:43 +01:00
NeilBrown
aba336bd1d md: raid1/raid10: fix problem with merge_bvec_fn
The new merge_bvec_fn which calls the corresponding function
in subsidiary devices requires that mddev->merge_check_needed
be set if any child has a merge_bvec_fn.

However were were only setting that when a device was hot-added,
not when a device was present from the start.

This bug was introduced in 3.4 so patch is suitable for 3.4.y
kernels.  However that are conflicts in raid10.c so a separate
patch will be needed for 3.4.y.

Cc: stable@vger.kernel.org
Reported-by: Sebastian Riemer <sebastian.riemer@profitbricks.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-31 15:56:30 +10:00
Linus Torvalds
c80ddb5263 md updates for 3.5
Main features:
  - RAID10 arrays can be reshapes - adding and removing devices and
    changing chunks (not 'far' array though)
  - allow RAID5 arrays to be reshaped with a backup file (not tested
    yet, but the priciple works fine for RAID10).
  - arrays can be reshaped while a bitmap is present - you no longer
    need to remove it first
  - SSSE3 support for RAID6 syndrome calculations
 
 and of course a number of minor fixes etc.
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Merge tag 'md-3.5' of git://neil.brown.name/md

Pull md updates from NeilBrown:
 "It's been a busy cycle for md - lots of fun stuff here..  if you like
  this kind of thing :-)

  Main features:
   - RAID10 arrays can be reshaped - adding and removing devices and
     changing chunks (not 'far' array though)
   - allow RAID5 arrays to be reshaped with a backup file (not tested
     yet, but the priciple works fine for RAID10).
   - arrays can be reshaped while a bitmap is present - you no longer
     need to remove it first
   - SSSE3 support for RAID6 syndrome calculations

  and of course a number of minor fixes etc."

* tag 'md-3.5' of git://neil.brown.name/md: (56 commits)
  md/bitmap: record the space available for the bitmap in the superblock.
  md/raid10: Remove extras after reshape to smaller number of devices.
  md/raid5: improve removal of extra devices after reshape.
  md: check the return of mddev_find()
  MD RAID1: Further conditionalize 'fullsync'
  DM RAID: Use md_error() in place of simply setting Faulty bit
  DM RAID: Record and handle missing devices
  DM RAID: Set recovery flags on resume
  md/raid5: Allow reshape while a bitmap is present.
  md/raid10: resize bitmap when required during reshape.
  md: allow array to be resized while bitmap is present.
  md/bitmap: make sure reshape request are reflected in superblock.
  md/bitmap: add bitmap_resize function to allow bitmap resizing.
  md/bitmap: use DIV_ROUND_UP instead of open-code
  md/bitmap: create a 'struct bitmap_counts' substructure of 'struct bitmap'
  md/bitmap: make bitmap bitops atomic.
  md/bitmap: make _page_attr bitops atomic.
  md/bitmap: merge bitmap_file_unmap and bitmap_file_put.
  md/bitmap: remove async freeing of bitmap file.
  md/bitmap: convert some spin_lock_irqsave to spin_lock_irq
  ...
2012-05-23 17:08:40 -07:00
NeilBrown
1dff2b87a3 md/bitmap: record the space available for the bitmap in the superblock.
Now that bitmaps can grow and shrink it is best if we record
how much space is available.  This means that when
we reduce the size of the bitmap we won't "lose" the space
for late when we might want to increase the size of the bitmap
again.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:34 +10:00
NeilBrown
63aced6102 md/raid10: Remove extras after reshape to smaller number of devices.
When a reshape which reduced the number of devices finishes
we must remove the extra devices.

So ensure  that raid10_remove_disk won't try to keep them, and
have raid10_finish_reshape clear the 'in_sync' flag.  Then
remove_and_add_spares will be able to remove them.

Reported-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:33 +10:00
NeilBrown
da7613b8b0 md/raid5: improve removal of extra devices after reshape.
After a reshape which reduced the number of devices we need
to disconnect the extra devices.
The code for this doesn't currently handle 'replacement' devices.
It is very unlikely that such devices will be present, but it is
safest to handle them anyway.

So simplify the handling.  Just clear In_sync and leave it
to remove_and_add_spaces (which will be called soon) to do
the real works.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:33 +10:00
Yuanhan Liu
0c098220e2 md: check the return of mddev_find()
Check the return of mddev_find(), since it may fail due to out of
memeory or out of usable minor number.

The reason I chose -ENODEV instead of -ENOMEM or something else is
md_alloc() function chose that ;)

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:32 +10:00
Jonathan Brassow
4f0a5e012c MD RAID1: Further conditionalize 'fullsync'
A RAID1 device does not necessarily need a fullsync if the bitmap can be used instead.

Similar to commit d6b212f4b1 in raid5.c, if a raid1
device can be brought back (i.e. from a transient failure) it shouldn't need a
complete resync.  Provided the bitmap is not to old, it will have recorded the areas
of the disk that need recovery.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:31 +10:00
Jonathan Brassow
c32fb9e7ec DM RAID: Use md_error() in place of simply setting Faulty bit
When encountering an error while reading the superblock, call md_error.

We are currently setting the 'Faulty' bit on one of the array devices when an
error is encountered while reading the superblock of a dm-raid array.  We should
be calling md_error(), as it handles the error more completely.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:31 +10:00
Jonathan Brassow
81f382f9e0 DM RAID: Record and handle missing devices
Missing dm-raid devices should be recorded in the superblock

When specifying the devices that compose a DM RAID array, it is possible to denote
failed or missing devices with '-'s.  When this occurs, we must record this in the
superblock.  We do this by checking if the array position's data device is missing
and then forcing MD to record the superblock by setting 'MD_CHANGE_DEVS' in
'raid_resume'.  If we do not cause the superblock to be rewritten by the resume
function, it is possible for a stale superblock to be written by an out-going
in-active table (during 'raid_dtr').

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:30 +10:00
Jonathan Brassow
47525e59e4 DM RAID: Set recovery flags on resume
Properly initialize MD recovery flags when resuming device-mapper devices.

When a device-mapper device is suspended, all I/O must stop.  This is done by
calling 'md_stop_writes' and 'mddev_suspend'.  These calls in-turn manipulate
the recovery flags - including setting 'MD_RECOVERY_FROZEN'.  The DM device
may have been suspended while recovery was not yet complete, so the process
needs to pick-up where it left off.  Since 'mddev_resume' does not unset
'MD_RECOVERY_FROZEN' and set 'MD_RECOVERY_NEEDED', we must do it ourselves.
'MD_RECOVERY_NEEDED' can safely be set in 'mddev_resume', but 'MD_RECOVERY_FROZEN'
must be set outside of 'mddev_resume' due to how MD handles RAID reshaping.
(e.g.  It is possible for a user to delay reshaping a RAID5->RAID6 by purposefully
setting 'MD_RECOVERY_FROZEN'.  Clearing it in 'mddev_resume' would override the
desired behavior.)

Because 'mddev_resume' already unconditionally calls 'md_wakeup_thread(mddev->thread)'
there is no need to make this call from 'raid_resume' since it calls 'mddev_resume'.

Also clean up where  level_store calls mddev_resume() - it current
duplicates some of the funcitons of that call. - NB

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:29 +10:00
NeilBrown
30b67645fa md/raid5: Allow reshape while a bitmap is present.
We always should have allowed this.  A raid5 reshape doesn't change
the size of the bitmap, so not need to restrict it.

Also add a test to make sure we don't try to start a reshape on a
failed array.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:28 +10:00
NeilBrown
bb63a7019d md/raid10: resize bitmap when required during reshape.
If a reshape changes the size of the array, then we can now
update the bitmap to suit - so do so.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:28 +10:00
NeilBrown
a4a6125a07 md: allow array to be resized while bitmap is present.
Now that bitmaps can be resized, we can allow an array to be resized
while the bitmap is present.

This only covers resizing that involves changing the effective size
of member devices, not resizing that changes the number of devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:27 +10:00
NeilBrown
b81a040481 md/bitmap: make sure reshape request are reflected in superblock.
As a reshape may change the sync_size and/or chunk_size, we need
to update these whenever we write out the bitmap superblock.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:26 +10:00
NeilBrown
d60b479d17 md/bitmap: add bitmap_resize function to allow bitmap resizing.
This function will allocate the new data structures and copy
bits across from old to new, allowing for the possibility that the
chunksize has changed.

Use the same function for performing the initial allocation
of the structures.  This improves test coverage.

When bitmap_resize is used to resize an existing bitmap, it
only copies '1' bits in, not '0' bits.
So when allocating the bitmap, ensure everything is initialised
to ZERO.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:25 +10:00
NeilBrown
15702d7fb6 md/bitmap: use DIV_ROUND_UP instead of open-code
Also take the opportunity to simplify CHUNK_BLOCK_RATIO.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:25 +10:00
NeilBrown
40cffcc0e8 md/bitmap: create a 'struct bitmap_counts' substructure of 'struct bitmap'
The new "struct bitmap_counts" contains all the fields that are
related to counting the number of active writes in each bitmap chunk.

Having this separate will make it easier to change the chunksize
or overall size of a bitmap atomically.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:24 +10:00
NeilBrown
63c68268b2 md/bitmap: make bitmap bitops atomic.
This allows us to remove spinlock protection which is
more heavy-weight than simple atomics.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:23 +10:00
NeilBrown
bdfd114073 md/bitmap: make _page_attr bitops atomic.
Using e.g. set_bit instead of __set_bit and using test_and_clear_bit
allow us to remove some locking and contract other locked ranges.

It is rare that we set or clear a lot of these bits, so gain should
outweigh any cost.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:22 +10:00
NeilBrown
fae7d326cd md/bitmap: merge bitmap_file_unmap and bitmap_file_put.
There functions really do one thing together: release the
'bitmap_storage'.  So make them just one function.

Since we removed the locking (previous patch), we don't need to zero
any fields before freeing them, so it all becomes a bit simpler.


Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:21 +10:00
NeilBrown
62f82faace md/bitmap: remove async freeing of bitmap file.
There is no real value in freeing things the moment there is an error.
It is just as good to free the bitmap file and pages when the bitmap
is explicitly removed (and replaced?) or at shutdown.

With this gone, the bitmap will only disappear when the array is
quiescent, so we can remove some locking.

As the 'filemap' doesn't disappear now, include extra checks before
trying to write any of it out.
Also remove the check for "has it disappeared" in
bitmap_daemon_write().


Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:21 +10:00
NeilBrown
7466712347 md/bitmap: convert some spin_lock_irqsave to spin_lock_irq
All of these sites can only be called from process context with
irqs enabled, so using irqsave/irqrestore just adds noise.
Remove it.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:19 +10:00
NeilBrown
b405fe91e5 md/bitmap: use set_bit, test_bit, etc for operation on bitmap->flags.
We currently use '&' and '|' which isn't the norm in the kernel
and doesn't allow easy atomicity.
So change to bit numbers and {set,clear,test}_bit.
This allows us to remove a spinlock/unlock (which was dubious anyway)
and some other simplifications.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:15 +10:00
NeilBrown
84e923453e md/bitmap: remove single-bit manipulation on sb->state
Just do single-bit manipulations on bitmap->flags and copy whole
value between that and sb->state.

This will allow next patch which changes how bit manipulations are
performed on bitmap->flags.

This does result in BITMAP_STALE not being set in sb by
bitmap_read_sb, however as the setting is determined by other
information in the 'sb' we do not lose information this way.
Normally, bitmap_load will be called shortly which will clear
BITMAP_STALE anyway.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:14 +10:00
NeilBrown
edbb79df67 md/bitmap: remove bitmap_mask_state
This function isn't really needed.  It sets or clears a flag in both
bitmap->flags and sb->state.
However both times it is called, bitmap_update_sb is called soon
afterwards which copies bitmap->flags to sb->state.
So just make changes to bitmap->flags, and open-code those rather than
hiding in a function.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:13 +10:00
NeilBrown
bc9891a885 md/bitmap: move storage allocation from bitmap_load to bitmap_create.
We should allocate memory for the storage-bitmap at create-time, not
load time.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:12 +10:00
NeilBrown
d1244cb062 md/bitmap: separate bitmap file allocation to its own function.
This will allow allocation before swapping in a new bitmap.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:12 +10:00
NeilBrown
9b1215c102 md/bitmap: store bytes in file rather than just in last page.
This number is more generally useful, and bytes-in-last-page is
easily extracted from it.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:11 +10:00
NeilBrown
1ec885cdd0 md/bitmap: move some fields of 'struct bitmap' into a 'storage' substruct.
This new 'struct bitmap_storage' reflects the external storage of the
bitmap.
Having this clearly defined will make it easier to change the storage
used while the array is active.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:10 +10:00
NeilBrown
d189122d4b md/bitmap: change *_page_attr() to take a page number, not a page.
Most often we have the page number, not the page.  And that is what
the  *_page_attr() functions really want.  So change the arguments to
take that number.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:09 +10:00
NeilBrown
27581e5ae0 md/bitmap: centralise allocation of bitmap file pages.
Instead of allocating pages in read_sb_page, read_page and
bitmap_read_sb, allocate them all in bitmap_init_from disk.

Also replace the hack of calling "attach_page_buffers(page, NULL)" to
ensure that free_buffer() won't complain, by putting a test for
PagePrivate in free_buffer().

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:08 +10:00
NeilBrown
ef99bf480d md/bitmap: allow a bitmap with no backing storage.
An md bitmap comprises two parts
 - internal counting of active writes per 'chunk'.
 - external storage of whether there are any active writes on
   each chunk

The second requires the first, but the first doesn't require the
second.

Not having backing storage means that the bitmap cannot expedite
resync after a crash, but it still allows us to expedite the recovery
of a recently-removed device.

So: allow a bitmap to exist even if there is no backing device.
In that case we default to 128M chunks.

A particular value of this is that we can remove and re-add a bitmap
(possibly of a different granularity) on a degraded array, and not
lose the information needed to fast-recover the missing device.

We don't actually activate these bitmaps yet - that will come
in a later patch.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:08 +10:00
NeilBrown
6409bb05a9 md/bitmap: add new 'space' attribute for bitmaps.
If we are to allow bitmaps to be resized when the array is resized,
we need to know how much space there is.

So create an attribute to store this information and set appropriate
defaults.

It can be set more precisely via sysfs, or future metadata extensions
may allow it to be recorded.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:07 +10:00
NeilBrown
bf07bb7d5b md/bitmap: disentangle two different 'pending' flags.
There are two different 'pending' concepts in the handling of the
write intent bitmap.

Firstly, a 'page' from the bitmap (which container PAGE_SIZE*8 bits)
may have changes (bits cleared) that should be written in due course.
There is no hurry for these and the page will transition from
PENDING to NEEDWRITE and will then be written, though if it ever
becomes DIRTY it will be written much sooner and PENDING will be
cleared.

Secondly, a page of counters - which contains PAGE_SIZE/2 counters, one
for each bit, can usefully have a 'pending' flag which indicates if
any of the counters are low (2 or 1) and ready to be processed by
bitmap_daemon_work().  If this flag is clear we can skip the whole
page.

These two concepts are currently combined in the bitmap-file flag.
This causes a tighter connection between the counters and the bitmap
file than I would like - as I want to add some flexibility to the
bitmap file.

So introduce a new flag with the page-of-counters, and rewrite
bitmap_daemon_work() so that it handles the two different 'pending'
concepts separately.

This also allows us to clear BITMAP_PAGE_PENDING when we write out
a dirty page, which may occasionally reduce the number of times we
write a page.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:06 +10:00
Shaohua Li
bc0934f047 raid5: support sync request
REQ_SYNC is ignored in current raid5 code. Block layer does use it to do
policy,
for example ioscheduler. This patch adds it.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:05 +10:00
Shaohua Li
cceeca43b5 raid5: remove unused variables
The two variables are useless.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:04 +10:00
majianpeng
5fdd2cf826 md/raid10: Fix memleak in r10buf_pool_alloc
If the allocation of rep1_bio fails, we currently don't free the 'bio'
of the same dev.

Reported by kmemleak.

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:03 +10:00
majianpeng
da8840a747 md/raid1: allow fix_read_error to read from recovering device.
When attempting to fix a read error, it is acceptable to read from a
device that is recovering, provided the recovery has got past the
place we are reading from.  This makes the test for "can we read from
here" the same as the test in read_balance.

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:03 +10:00
NeilBrown
4fa2f32768 md: move freeing of badblocks.page into md_rdev_clear
This ensures that it is always freed - there were case where
we failed to free the page.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:55:01 +10:00
NeilBrown
545c87957f md: dm-raid should call helper function to clear rdev.
dm-raid currently open-codes the freeing of some members of
and rdev.  It is more maintainable to have it call common code
from md.c which does this for all call-sites.

So remove free_disk_sb to md_rdev_clear, export it, and use it in
dm-raid.c

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:54:30 +10:00
NeilBrown
3ea7daa5d7 md/raid10: add reshape support
A 'near' or 'offset' lay RAID10 array can be reshaped to a different
'near' or 'offset' layout, a different chunk size, and a different
number of devices.
However the number of copies cannot change.

Unlike RAID5/6, we do not support having user-space backup data that
is being relocated during a 'critical section'.  Rather, the
data_offset of each device must change so that when writing any block
to a new location, it will not over-write any data that is still
'live'.

This means that RAID10 reshape is not supportable on v0.90 metadata.

The different between the old data_offset and the new_offset must be
at least the larger of the chunksize multiplied by offset copies of
each of the old and new layout. (for 'near' mode, offset_copies == 1).

A larger difference of around 64M seems useful for in-place reshapes
as more data can be moved between metadata updates.
Very large differences (e.g. 512M) seem to slow the process down due
to lots of long seeks (on oldish consumer graded devices at least).

Metadata needs to be updated whenever the place we are about to write
to is considered - by the current metadata - to still contain data in
the old layout.

[unbalanced locking fix from Dan Carpenter <dan.carpenter@oracle.com>]

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-22 13:53:47 +10:00
NeilBrown
deb200d085 md/raid10: split out interpretation of layout to separate function.
We will soon be interpreting the layout (and chunksize etc) from
multiple places to support reshape.  So split it out into separate
function.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:28:33 +10:00
NeilBrown
f8c9e74ff0 md/raid10: Introduce 'prev' geometry to support reshape.
When RAID10 supports reshape it will need a 'previous' and a 'current'
geometry, so introduce that here.
Use the 'prev' geometry when before the reshape_position, and the
current 'geo' when beyond it.  At other times, use both as
appropriate.

For now, both are identical (And reshape_position is never set).

When we use the 'prev' geometry, we must use the old data_offset.
When we use the current (And a reshape is happening) we must use
the new_data_offset.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:28:33 +10:00
NeilBrown
c804cdecea md: use resync_max_sectors for reshape as well as resync.
Some resync type operations need to act on the address space of the
device, others on the address space of the array.

This only affects RAID10, so it sets resync_max_sectors to the array
size (it defaults to the device size), and that is currently used for
resync only.  However reshape of a RAID10 must be done against the
array size, not device size, so change code to use resync_max_sectors
for both the resync and the reshape cases.
This does not affect RAID5 or RAID1, just RAID10.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:28:33 +10:00
NeilBrown
1fdd6fc92f md: teach sync_page_io about new_data_offset.
Some code in raid1 and raid10 use sync_page_io to
read/write pages when responding to read errors.
As we will shortly support changing data_offset for
raid10, this function must understand new_data_offset.

So add that understanding.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:28:32 +10:00
NeilBrown
5cf00fcd3c md/raid10: collect some geometry fields into a dedicated structure.
We will shortly be adding reshape support for RAID10 which will
require it having 2 concurrent geometries (before and after).
To make that easier, collect most geometry fields into 'struct geom'
and access them from there.  Then we will more easily be able to add
a second set of fields.

Note that 'copies' is not in this struct and so cannot be changed.
There is little need to change this number and doing so is a lot
more difficult as it requires reallocating more things.
So leave it out for now.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:28:20 +10:00
NeilBrown
b5254dd5fd md/raid5: allow for change in data_offset while managing a reshape.
The important issue here is incorporating the different in data_offset
into calculations concerning when we might need to over-write data
that is still thought to be valid.

To this end we find the minimum offset difference across all devices
and add that where appropriate.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:27:01 +10:00
NeilBrown
05616be5e1 md/raid5: Use correct data_offset for all IO.
As there can now be two different data_offsets - an 'old' and
a 'new' - we need to carefully choose between them.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:27:00 +10:00
NeilBrown
c6563a8c38 md: add possibility to change data-offset for devices.
When reshaping we can avoid costly intermediate backup by
changing the 'start' address of the array on the device
(if there is enough room).

So as a first step, allow such a change to be requested
through sysfs, and recorded in v1.x metadata.

(As we didn't previous check that all 'pad' fields were zero,
 we need a new FEATURE flag for this.
 A (belatedly) check that all remaining 'pad' fields are
 zero to avoid a repeat of this)

The new data offset must be requested separately for each device.
This allows each to have a different change in the data offset.
This is not likely to be used often but as data_offset can be
set per-device, new_data_offset should be too.

This patch also removes the 'acknowledged' arg to rdev_set_badblocks as
it is never used and never will be.  At the same time we add a new
arg ('in_new') which is currently always zero but will be used more
soon.

When a reshape finishes we will need to update the data_offset
and rdev->sectors.  So provide an exported function to do that.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:27:00 +10:00
NeilBrown
2c810cddc4 md: allow a reshape operation to be reversed.
Currently a reshape operation always progresses from the start
of the array to the end unless the number of devices is being
reduced, in which case it progressed in the opposite direction.

To reverse a partial reshape which changes the number of devices
you can stop the array and re-assemble with the raid-disks numbers
reversed and it will undo.

However for a reshape that does not change the number of devices
it is not possible to reverse the reshape in the middle - you have to
wait until it completes.

So add a 'reshape_direction' attribute with is either 'forwards' or
'backwards' and can be explicitly set when delta_disks is zero.

This will become more important when we allow the data_offset to
change in a reshape.  Then the explicit statement of what direction is
being used will be more useful.

This can be enabled in raid5 trivially as it already supports
reverse reshape and just needs to use a different trigger to request it.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:27:00 +10:00
Shaohua Li
b5e1b8cee7 md: using GFP_NOIO to allocate bio for flush request
A flush request is usually issued in transaction commit code path, so
using GFP_KERNEL to allocate memory for flush request bio falls into
the classic deadlock issue.

This is suitable for any -stable kernel to which it applies as it
avoids a possible deadlock.

Cc: stable@vger.kernel.org
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-21 09:26:59 +10:00
Linus Torvalds
b1dab2f040 A fix to the thin provisioning userspace interface.
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Merge tag 'dm-3.4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull a dm fix from Alasdair G Kergon:
 "A fix to the thin provisioning userspace interface."

* tag 'dm-3.4-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm thin: fix table output when pool target disables discard passdown internally
2012-05-18 18:22:45 -07:00
Mike Snitzer
f402693d06 dm thin: fix table output when pool target disables discard passdown internally
When the thin pool target clears the discard_passdown parameter
internally, it incorrectly changes the table line reported to userspace.
This breaks dumb string comparisons on these table lines in generic
userspace device-mapper library code and leads to tables being reloaded
repeatedly when nothing is actually meant to be changing.

This patch corrects this by no longer changing the table line when
discard passdown was disabled.

We can still tell when discard passdown is overridden by looking for the
message "Discard unsupported by data device (sdX): Disabling discard passdown."

This automatic detection is also moved from the 'load' to the 'resume'
so that it is re-evaluated should the properties of underlying devices
change.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-05-19 01:01:01 +01:00
Linus Torvalds
2f05af8b59 Fix bug in recent fix to RAID10.
Without this patch, recovery will crash
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Merge tag 'md-3.4-fixes' of git://neil.brown.name/md

Pull one more md bugfix from NeilBrown:
 "Fix bug in recent fix to RAID10.

  Without this patch, recovery will crash"

* tag 'md-3.4-fixes' of git://neil.brown.name/md:
  md/raid10: fix transcription error in calc_sectors conversion.
2012-05-18 16:19:59 -07:00
NeilBrown
b0d634d568 md/raid10: fix transcription error in calc_sectors conversion.
The old code was
		sector_div(stride, fc);
the new code was
		sector_dir(size, conf->near_copies);

'size' is right (the stride various wasn't really needed), but
'fc' means 'far_copies', and that is an important difference.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-19 09:01:13 +10:00
Linus Torvalds
36a1987cd8 md: 2 fixes for 3.4
one fixes a bug in the new raid10 resize code so is relevant
 to 3.4 only
 Other fixes a bug in the use of md by dm-raid, so is relevant
 to any kernel with dm-raid support
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Merge tag 'md-3.4-fixes' of git://neil.brown.name/md

Pull two md fixes from NeilBrown:
 "One fixes a bug in the new raid10 resize code so is relevant to 3.4
  only.

  The other fixes a bug in the use of md by dm-raid, so is relevant to
  any kernel with dm-raid support"

* tag 'md-3.4-fixes' of git://neil.brown.name/md:
  MD: Add del_timer_sync to mddev_suspend (fix nasty panic)
  md/raid10: set dev_sectors properly when resizing devices in array.
2012-05-17 09:44:35 -07:00
Jonathan Brassow
0d9f4f135e MD: Add del_timer_sync to mddev_suspend (fix nasty panic)
Use del_timer_sync to remove timer before mddev_suspend finishes.

We don't want a timer going off after an mddev_suspend is called.  This is
especially true with device-mapper, since it can call the destructor function
immediately following a suspend.  This results in the removal (kfree) of the
structures upon which the timer depends - resulting in a very ugly panic.
Therefore, we add a del_timer_sync to mddev_suspend to prevent this.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-17 10:38:24 +10:00
NeilBrown
6508fdbf40 md/raid10: set dev_sectors properly when resizing devices in array.
raid10 stores dev_sectors in 'conf' separately from the one in
'mddev' because it can have a very significant effect on block
addressing and so need to be updated carefully.

However raid10_resize isn't updating it at all!

To update it correctly, we need to make sure it is a proper
multiple of the chunksize taking various details of the layout
in to account.
This calculation is currently done in setup_conf.   So split it
out from there and call it from raid10_resize as well.
Then set conf->dev_sectors properly.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-17 10:08:45 +10:00
Linus Torvalds
4a873f5399 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David S. Miller:

 1) Since we do RCU lookups on ipv4 FIB entries, we have to test if the
    entry is dead before returning it to our caller.

 2) openvswitch locking and packet validation fixes from Ansis Atteka,
    Jesse Gross, and Pravin B Shelar.

 3) Fix PM resume locking in IGB driver, from Benjamin Poirier.

 4) Fix VLAN header handling in vhost-net and macvtap, from Basil Gor.

 5) Revert a bogus network namespace isolation change that was causing
    regressions on S390 networking devices.

 6) If bonding decides to process and handle a LACPDU frame, we
    shouldn't bump the rx_dropped counter.  From Jiri Bohac.

 7) Fix mis-calculation of available TX space in r8169 driver when doing
    TSO, which can lead to crashes and/or hung device.  From Julien
    Ducourthial.

 8) SCTP does not validate cached routes properly in all cases, from
    Nicolas Dichtel.

 9) Link status interrupt needs to be handled in ks8851 driver, from
    Stephen Boyd.

10) Use capable(), not cap_raised(), in connector/userns netlink code.
    From Eric W. Biederman via Andrew Morton.

11) Fix pktgen OOPS on module unload, from Eric Dumazet.

12) iwlwifi under-estimates SKB truesizes, also from Eric Dumazet.

13) Cure division by zero in SFC driver, from Ben Hutchings.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  ks8851: Update link status during link change interrupt
  macvtap: restore vlan header on user read
  vhost-net: fix handle_rx buffer size
  bonding: don't increase rx_dropped after processing LACPDUs
  connector/userns: replace netlink uses of cap_raised() with capable()
  sctp: check cached dst before using it
  pktgen: fix crash at module unload
  Revert "net: maintain namespace isolation between vlan and real device"
  ehea: fix losing of NEQ events when one event occurred early
  igb: fix rtnl race in PM resume path
  ipv4: Do not use dead fib_info entries.
  r8169: fix unsigned int wraparound with TSO
  sfc: Fix division by zero when using one RX channel and no SR-IOV
  openvswitch: Validation of IPv6 set port action uses IPv4 header
  net: compare_ether_addr[_64bits]() has no ordering
  cdc_ether: Ignore bogus union descriptor for RNDIS devices
  bnx2x: bug fix when loading after SAN boot
  e1000: Silence sparse warnings by correcting type
  igb, ixgbe: netdev_tx_reset_queue incorrectly called from tx init path
  openvswitch: Release rtnl_lock if ovs_vport_cmd_build_info() failed.
  ...
2012-05-12 12:57:01 -07:00
Mike Snitzer
510193a2d3 dm mpath: check if scsi_dh module already loaded before trying to load
If the requested scsi_dh module is already loaded then skip
request_module().

Multipath table loads can hang in an unnecessary __request_module.

Reported-by: Ben Marzinski <bmarzins@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-05-12 01:43:21 +01:00
Alasdair G Kergon
7cab8bf160 dm thin: correct module description
Remove duplicate copy of string "device-mapper" (DM_NAME) from
MODULE_DESCRIPTION.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-05-12 01:43:19 +01:00
Mike Snitzer
c3a0ce2eab dm thin: fix unprotected use of prepared_discards list
Fix two places in commit 104655fd4d ("dm thin: support discards") that
didn't use pool->lock to protect against concurrent changes to the
prepared_discards list.

Without this fix, thin_endio() can race with process_discard(), leading
to concurrent list_add()s that result in the processes locking up with
an error like the following:

WARNING: at lib/list_debug.c:32 __list_add+0x8f/0xa0()
...
list_add corruption. next->prev should be prev (ffff880323b96140), but was ffff8801d2c48440. (next=ffff8801d2c485c0).
...
Pid: 17205, comm: kworker/u:1 Tainted: G        W  O 3.4.0-rc3.snitm+ #1
Call Trace:
 [<ffffffff8103ca1f>] warn_slowpath_common+0x7f/0xc0
 [<ffffffff8103cb16>] warn_slowpath_fmt+0x46/0x50
 [<ffffffffa04f6ce6>] ? bio_detain+0xc6/0x210 [dm_thin_pool]
 [<ffffffff8124ff3f>] __list_add+0x8f/0xa0
 [<ffffffffa04f70d2>] process_discard+0x2a2/0x2d0 [dm_thin_pool]
 [<ffffffffa04f6a78>] ? remap_and_issue+0x38/0x50 [dm_thin_pool]
 [<ffffffffa04f7c3b>] process_deferred_bios+0x7b/0x230 [dm_thin_pool]
 [<ffffffffa04f7df0>] ? process_deferred_bios+0x230/0x230 [dm_thin_pool]
 [<ffffffffa04f7e42>] do_worker+0x52/0x60 [dm_thin_pool]
 [<ffffffff81056fa9>] process_one_work+0x129/0x450
 [<ffffffff81059b9c>] worker_thread+0x17c/0x3c0
 [<ffffffff81059a20>] ? manage_workers+0x120/0x120
 [<ffffffff8105eabe>] kthread+0x9e/0xb0
 [<ffffffff814ceda4>] kernel_thread_helper+0x4/0x10
 [<ffffffff8105ea20>] ? kthread_freezable_should_stop+0x70/0x70
 [<ffffffff814ceda0>] ? gs_change+0x13/0x13
---[ end trace 7e0a523bc5e52692 ]---

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-05-12 01:43:16 +01:00
Mike Snitzer
03aaae7cdc dm thin: reinstate missing mempool_free in cell_release_singleton
Fix a significant memory leak inadvertently introduced during
simplification of cell_release_singleton() in commit
6f94a4c45a ("dm thin: fix stacked bi_next
usage").

A cell's hlist_del() must be accompanied by a mempool_free().
Use __cell_release() to do this, like before.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-05-12 01:43:12 +01:00
Eric W. Biederman
38bf195398 connector/userns: replace netlink uses of cap_raised() with capable()
In 2009 Philip Reiser notied that a few users of netlink connector
interface needed a capability check and added the idiom
cap_raised(nsp->eff_cap, CAP_SYS_ADMIN) to a few of them, on the premise
that netlink was asynchronous.

In 2011 Patrick McHardy noticed we were being silly because netlink is
synchronous and removed eff_cap from the netlink_skb_params and changed
the idiom to cap_raised(current_cap(), CAP_SYS_ADMIN).

Looking at those spots with a fresh eye we should be calling
capable(CAP_SYS_ADMIN).  The only reason I can see for not calling capable
is that it once appeared we were not in the same task as the caller which
would have made calling capable() impossible.

In the initial user_namespace the only difference between between
cap_raised(current_cap(), CAP_SYS_ADMIN) and capable(CAP_SYS_ADMIN) are a
few sanity checks and the fact that capable(CAP_SYS_ADMIN) sets
PF_SUPERPRIV if we use the capability.

Since we are going to be using root privilege setting PF_SUPERPRIV seems
the right thing to do.

The motivation for this that patch is that in a child user namespace
cap_raised(current_cap(),...) tests your capabilities with respect to that
child user namespace not capabilities in the initial user namespace and
thus will allow processes that should be unprivielged to use the kernel
services that are only protected with cap_raised(current_cap(),..).

To fix possible user_namespace issues and to just clean up the code
replace cap_raised(current_cap(), CAP_SYS_ADMIN) with
capable(CAP_SYS_ADMIN).

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Acked-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-10 23:21:39 -04:00
NeilBrown
b16b1b6cd0 md/bitmap: fix calculation of 'chunks' - missing shift.
commit 61a0d80c "md/bitmap: discard CHUNK_BLOCK_SHIFT macro"
replaced CHUNK_BLOCK_RATIO() by the same text that was
replacing CHUNK_BLOCK_SHIFT() - which is clearly wrong.

The result is that 'chunks' is often too small by 1,
which can sometimes result in a crash (not sure how).

So use the correct replacement, and get rid of CHUNK_BLOCK_RATIO
which is no longe used.

Reported-by: Karl Newman <siliconfiend@gmail.com>
Tested-by: Karl Newman <siliconfiend@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-05-04 17:03:18 +10:00
NeilBrown
30b8aa9172 md: fix possible corruption of array metadata on shutdown.
commit c744a65c1e
  md: don't set md arrays to readonly on shutdown.

removed the possibility of a 'BUG' when data is written to an array
that has just been switched to read-only, but also introduced the
possibility that the array metadata could be corrupted.

If, when md_notify_reboot gets the mddev lock, the array is
in a state where it is assembled but hasn't been started (as can
happen if the personality module is not available, or in other unusual
situations), then incorrect metadata will be written out making it
impossible to re-assemble the array.

So only call __md_stop_writes() if the array has actually been
activated.

This patch is needed for any stable kernel which has had the above
commit applied.

Cc: stable@vger.kernel.org
Reported-by: Christoph Nelles <evilazrael@evilazrael.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-24 10:23:16 +10:00
NeilBrown
ed209584c3 md: don't call ->add_disk unless there is good reason.
Commit 7bfec5f35c

   md/raid5: If there is a spare and a want_replacement device, start replacement.

cause md_check_recovery to call ->add_disk much more often.
Instead of only when the array is degraded, it is now called whenever
md_check_recovery finds anything useful to do, which includes
updating the metadata for clean<->dirty transition.
This causes unnecessary work, and causes info messages from ->add_disk
to be reported much too often.

So refine md_check_recovery to only do any actual recovery checking
(including ->add_disk) if MD_RECOVERY_NEEDED is set.

This fix is suitable for 3.3.y:

Cc: stable@vger.kernel.org
Reported-by: Jan Ceuleers <jan.ceuleers@computer.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-24 10:23:14 +10:00
Jonathan Brassow
a9ad8526bb DM RAID: Use safe version of rdev_for_each
Fix segfault caused by using rdev_for_each instead of rdev_for_each_safe

Commit dafb20fa34 mistakenly replaced a safe
iterator with an unsafe one when making some macro changes.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-24 10:23:13 +10:00
NeilBrown
afbaa90b80 md/bitmap: prevent bitmap_daemon_work running while initialising bitmap
If a bitmap is added while the array is active, it is possible
for bitmap_daemon_work to run while the bitmap is being
initialised.
This is particularly a problem if bitmap_daemon_work sees
bitmap->filemap as non-NULL before it has been filled in properly.
So hold bitmap_info.mutex while filling in ->filemap
to prevent problems.

This patch is suitable for any -stable kernel, though it might not
apply cleanly before about 3.1.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-12 16:05:06 +10:00
majianpeng
f4380a9158 md/raid1,raid10: Fix calculation of 'vcnt' when processing error recovery.
If r1bio->sectors % 8 != 0,then the memcmp and a later
memcpy will omit the last bio_vec.

This is suitable for any stable kernel since 3.1 when bad-block
management was introduced.

Cc: stable@vger.kernel.org
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-12 16:04:47 +10:00
Andrei Warkentin
9e41dd35b3 MD: Bitmap version cleanup.
bitmap_new_disk_sb() would still create V3 bitmap superblock
with host-endian layout.

Perhaps I'm confused, but shouldn't bitmap_new_disk_sb() be
creating a V4 bitmap superblock instead, that is portable,
as per comment in bitmap.h?

Signed-off-by: Andrei Warkentin <andrey.warkentin@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-12 15:55:21 +10:00
NeilBrown
5020ad7d14 md/raid1,raid10: don't compare excess byte during consistency check.
When comparing two pages read from different legs of a mirror, only
compare the bytes that were read, not the whole page.

In most cases we read a whole page, but in some cases with
bad blocks or odd sizes devices we might read fewer than that.

This bug has been present "forever" but at worst it might cause
a report of two many mismatches and generate a little bit
extra resync IO, so there is no need to back-port to -stable
kernels.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-03 15:39:23 +10:00
majianpeng
c6d2e084c7 md/raid5: Fix a bug about judging if the operation is syncing or replacing
When create a raid5 using assume-clean and echo check or repair to
sync_action.Then component disks did not operated IO but the raid
check/resync faster than normal.
Because the judgement in function analyse_stripe():
		if (do_recovery ||
		    sh->sector >= conf->mddev->recovery_cp)
			s->syncing = 1;
		else
			s->replacing = 1;
When check or repair,the recovery_cp == MaxSectore,so syncing equal zero
not one.

This bug was introduced by commit 9a3e1101b8
    md/raid5:  detect and handle replacements during recovery.
so this patch is suitable for 3.3-stable.

Cc: stable@vger.kernel.org
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-03 15:37:38 +10:00
majianpeng
a42f9d83b5 md/raid1:Remove unnecessary rcu_dereference(conf->mirrors[i].rdev).
Because rde->nr_pending > 0,so can not remove this disk.
And in any case, we aren't holding rcu_read_lock()

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-03 15:37:33 +10:00
Jes Sorensen
24b961f811 md: Avoid OOPS when reshaping raid1 to raid0
raid1 arrays do not have the notion of chunk size. Calculate the
largest chunk sector size we can use to avoid a divide by zero OOPS
when aligning the size of the new array to the chunk size.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-03 15:37:26 +10:00
NeilBrown
18b9837ea0 md/raid5: fix handling of bad blocks during recovery.
1/ We can only treat a known-bad-block like a read-error if we
   have the data that belongs in that block.  So fix that test.

2/ If we cannot recovery a stripe due to insufficient data,
   don't tell "md_done_sync" that the sync failed unless we really
   did fail something.  If we successfully record bad blocks,
   that is success.

Reported-by: "majianpeng" <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-03 15:36:17 +10:00
majianpeng
5220ea1e64 md/raid1: If md_integrity_register() failed,run() must free the mem
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-02 09:48:38 +10:00
majianpeng
0366ef8475 md/raid0: If md_integrity_register() fails, raid0_run() must free the mem.
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-02 09:48:37 +10:00
majianpeng
98d5561bfb md/linear: If md_integrity_register() fails, linear_run() must free the mem.
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-04-02 09:48:37 +10:00
Mikulas Patocka
a4ffc15219 dm: add verity target
This device-mapper target creates a read-only device that transparently
validates the data on one underlying device against a pre-generated tree
of cryptographic checksums stored on a second device.

Two checksum device formats are supported: version 0 which is already
shipping in Chromium OS and version 1 which incorporates some
improvements.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Elly Jones <ellyjones@chromium.org>
Cc: Milan Broz <mbroz@redhat.com>
Cc: Olof Johansson <olofj@chromium.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:43:38 +01:00
Mikulas Patocka
a66cc28f53 dm bufio: prefetch
This patch introduces a new function dm_bufio_prefetch. It prefetches
the specified range of blocks into dm-bufio cache without waiting
for i/o completion.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:29 +01:00
Joe Thornber
67e2e2b281 dm thin: add pool target flags to control discard
Add dm thin target arguments to control discard support.

ignore_discard: Disables discard support

no_discard_passdown: Don't pass discards down to the underlying data
device, but just remove the mapping within the thin provisioning target.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:29 +01:00
Joe Thornber
104655fd4d dm thin: support discards
Support discards in the thin target.

On discard the corresponding mapping(s) are removed from the thin
device.  If the associated block(s) are no longer shared the discard
is passed to the underlying device.

All bios other than discards now have an associated deferred_entry
that is saved to the 'all_io_entry' in endio_hook.  When non-discard
IO completes and associated mappings are quiesced any discards that
were deferred, via ds_add_work() in process_discard(), will be queued
for processing by the worker thread.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

drivers/md/dm-thin.c |  173 ++++++++++++++++++++++++++++++++++++++++++++++----
 drivers/md/dm-thin.c |  172 ++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 158 insertions(+), 14 deletions(-)
2012-03-28 18:41:28 +01:00
Joe Thornber
eb2aa48d4e dm thin: prepare to support discard
This patch contains the ground work needed for dm-thin to support discard.

  - Adds endio function that replaces shared_read_endio.

  - Introduce an explicit 'quiesced' flag into the new_mapping structure.
    Before, this was implicitly indicated by m->list being empty.

  - The map_info->ptr remains constant for the duration of a bio's trip
    through the thin target.  Make it easier to reason about it.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:28 +01:00
Alasdair G Kergon
6efd6e8309 dm thin: use dm_target_offset
Use dm_target_offset wrapper instead of referencing the awkward ti->begin
explicitly.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:28 +01:00
Joe Thornber
2dd9c257fb dm thin: support read only external snapshot origins
Support the use of an external _read only_ device as an origin for a thin
device.

Any read to an unprovisioned area of the thin device will be passed
through to the origin.  Writes trigger allocation of new blocks as
usual.

One possible use case for this would be VM hosts that want to run
guests on thinly-provisioned volumes but have the base image on another
device (possibly shared between many VMs).

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:28 +01:00
Mike Snitzer
c4a69ecdb4 dm thin: relax hard limit on the maximum size of a metadata device
The thin metadata format can only make use of a device that is <=
THIN_METADATA_MAX_SECTORS (currently 15.9375 GB).  Therefore, there is no
practical benefit to using a larger device.

However, it may be that other factors impose a certain granularity for
the space that is allocated to a device (E.g. lvm2 can impose a coarse
granularity through the use of large, >= 1 GB, physical extents).

Rather than reject a larger metadata device, during thin-pool device
construction, switch to allowing it but issue a warning if a device
larger than THIN_METADATA_MAX_SECTORS_WARNING (16 GB) is
provided.  Any space over 15.9375 GB will not be used.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:28 +01:00
Joe Thornber
71fd5ae25d dm persistent data: remove space map ref_count entries if redundant
Save space by removing entries from the space map ref_count tree if
they're no longer needed.

Ref counts are stored in two places: a bitmap if the ref_count is
below 3, or a btree of uint32_t if 3 or above.

When a ref_count that was above 3 drops below we can remove it from
the tree and save some metadata space.  This removal was commented out
before because I was unsure why this was causing under-populated btree
nodes.  Earlier patches have fixed this issue.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:27 +01:00
Joe Thornber
905e51b39a dm thin: commit outstanding data every second
Commit unwritten data every second to prevent too much building up.

Released blocks don't become available until after the next commit
(for crash resilience).  Prior to this patch commits were only
triggered by a message to the target or a REQ_{FLUSH,FUA} bio.  This
allowed far too big a position to build up.

The interval is hard-coded to 1 second.  This is a sensible setting.
I'm not making this user configurable, since there isn't much to be
gained by tweaking this - and a lot lost by setting it far too high.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:27 +01:00
Mikulas Patocka
31998ef193 dm: reject trailing characters in sccanf input
Device mapper uses sscanf to convert arguments to numbers. The problem is that
the way we use it ignores additional unmatched characters in the scanned string.

For example, this `if (sscanf(string, "%d", &number) == 1)' will match a number,
but also it will match number with some garbage appended, like "123abc".

As a result, device mapper accepts garbage after some numbers. For example
the command `dmsetup create vg1-new --table "0 16384 linear 254:1bla 34816bla"'
will pass without an error.

This patch fixes all sscanf uses in device mapper. It appends "%c" with
a pointer to a dummy character variable to every sscanf statement.

The construct `if (sscanf(string, "%d%c", &number, &dummy) == 1)' succeeds
only if string is a null-terminated number (optionally preceded by some
whitespace characters). If there is some character appended after the number,
sscanf matches "%c", writes the character to the dummy variable and returns 2.
We check the return value for 1 and consequently reject numbers with some
garbage appended.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:26 +01:00
Jonathan E Brassow
0447568fc5 dm raid: handle failed devices during start up
The dm-raid code currently fails to create a RAID array if any of the
superblocks cannot be read.  This was an oversight as there is already
code to handle this case if the values ('- -') were provided for the
failed array position.

With this patch, if a superblock cannot be read, the array position's
fields are initialized as though '- -' was set in the table.  That is,
the device is failed and the position should not be used, but if there
is sufficient redundancy, the array should still be activated.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:26 +01:00
Joe Thornber
fef838cc1a dm thin metadata: pass correct space map to dm_sm_root_size
Fix a harmless typo.

The root is a chunk of data that gets written to the superblock.  This
data is used to recreate the space map when opening a metadata area.
We have two space maps; one tracking space on the metadata device and
one of the data device.  Both of these use the same format for their
root, so this typo was harmless.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:25 +01:00
Joe Thornber
a3aefb395e dm persistent data: remove redundant value_size arg from value_ptr
Now that the value_size is held within every node of the btrees we can
remove this argument from value_ptr().

For the last few months a BUG_ON has been checking this argument is
the same as that held in the node.  No issues were reported.  So this
is a safe change.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:25 +01:00
Jun'ichi Nomura
466891f995 dm mpath: detect invalid map_context
The map_context pointer should always be set. However, we have reports
that upon requeuing it is not set correctly.  So add set and clear
functions with a BUG_ON() to track the issue properly.

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:25 +01:00
Hannes Reinecke
4d7b38b7d9 dm: clear bi_end_io on remapping failure
As a precaution, set bi_end_io to NULL when failing to remap.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:25 +01:00
Hannes Reinecke
574ce07eb0 dm table: simplify call to free_devices
free_devices in dm_table.c already uses list_for_each(), so we don't
need to check if the list is empty.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:24 +01:00
Joe Thornber
fe878f34df dm thin: correct comments
Remove documentation for unimplemented 'trim' message.

I'd planned a 'trim' target message for shrinking thin devices, but
this is better handled via the discard ioctl.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:24 +01:00
Alasdair G Kergon
035220b33d dm raid: no longer experimental
The dm raid module (using md) is becoming the preferred way of creating long-lived
mirrors through userspace LVM so remove the EXPERIMENTAL tag.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:24 +01:00
Alasdair G Kergon
e0b215da8f dm uevent: no longer experimental
Drop EXPERIMENTAL tag from dm-uevent.

It's not changed for a while and some userspace tools are relying upon it.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:24 +01:00
Joe Thornber
b0988900ba dm persistent data: fix btree rebalancing after remove
When we remove an entry from a node we sometimes rebalance with it's
two neighbours.  This wasn't being done correctly; in some cases
entries have to move all the way from the right neighbour to the left
neighbour, or vice versa.  This patch pretty much re-writes the
balancing code to fix it.

This code is barely used currently; only when you delete a thin
device, and then only if you have hundreds of them in the same pool.
Once we have discard support, which removes mappings, this will be used
much more heavily.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:23 +01:00
Joe Thornber
6f94a4c45a dm thin: fix stacked bi_next usage
Avoid using the bi_next field for the holder of a cell when deferring
bios because a stacked device below might change it.  Store the
holder in a new field in struct cell instead.

When a cell is created, the bio that triggered creation (the holder) was
added to the same bio list as subsequent bios.  In some cases we pass
this holder bio directly to devices underneath.  If those devices use
the bi_next field there will be trouble...

This also simplifies some code that had to work out which bio was the
holder.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:23 +01:00
Mikulas Patocka
72c6e7afc4 dm crypt: add missing error handling
Always set io->error to -EIO when an error is detected in dm-crypt.

There were cases where an error code would be set only if we finish
processing the last sector. If there were other encryption operations in
flight, the error would be ignored and bio would be returned with
success as if no error happened.

This bug is present in kcryptd_crypt_write_convert, kcryptd_crypt_read_convert
and kcryptd_async_done.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Reviewed-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:22 +01:00
Mikulas Patocka
aeb2deae26 dm crypt: fix mempool deadlock
This patch fixes a possible deadlock in dm-crypt's mempool use.

Currently, dm-crypt reserves a mempool of MIN_BIO_PAGES reserved pages.
It allocates first MIN_BIO_PAGES with non-failing allocation (the allocation
cannot fail and waits until the mempool is refilled). Further pages are
allocated with different gfp flags that allow failing.

Because allocations may be done in parallel, this code can deadlock. Example:
There are two processes, each tries to allocate MIN_BIO_PAGES and the processes
run simultaneously.
It may end up in a situation where each process allocates (MIN_BIO_PAGES / 2)
pages. The mempool is exhausted. Each process waits for more pages to be freed
to the mempool, which never happens.

To avoid this deadlock scenario, this patch changes the code so that only
the first page is allocated with non-failing gfp mask. Allocation of further
pages may fail.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:22 +01:00
Andrei Warkentin
aadbe266f2 dm exception store: fix init error path
Call the correct exit function on failure in dm_exception_store_init.

Signed-off-by: Andrei Warkentin <andrey.warkentin@gmail.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28 18:41:22 +01:00
Linus Torvalds
267d7b23dd md updates for 3.4
Mostly tidying up code in preparation for some bigger changes
 next time.
 A few bug fixes tagged for -stable.
 
 Main functionality change is that some RAID10 arrays can now
 grow to use extra space that may have been made available on the
 individual devices.
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Merge tag 'md-3.4' of git://neil.brown.name/md

Pull md updates for 3.4 from Neil Brown:
 "Mostly tidying up code in preparation for some bigger changes next
  time.

  A few bug fixes tagged for -stable.

  Main functionality change is that some RAID10 arrays can now grow to
  use extra space that may have been made available on the individual
  devices."

Fixed up trivial conflicts with the k[un]map_atomic() cleanups in
drivers/md/bitmap.c.

* tag 'md-3.4' of git://neil.brown.name/md: (22 commits)
  md: Add judgement bb->unacked_exist in function md_ack_all_badblocks().
  md: fix clearing of the 'changed' flags for the bad blocks list.
  md/bitmap: discard CHUNK_BLOCK_SHIFT macro
  md/bitmap: remove unnecessary indirection when allocating.
  md/bitmap: remove some pointless locking.
  md/bitmap: change a 'goto' to a normal 'if' construct.
  md/bitmap: move printing of bitmap status to bitmap.c
  md/bitmap: remove some unused noise from bitmap.h
  md/raid10 - support resizing some RAID10 arrays.
  md/raid1: handle merge_bvec_fn in member devices.
  md/raid10: handle merge_bvec_fn in member devices.
  md: add proper merge_bvec handling to RAID0 and Linear.
  md: tidy up rdev_for_each usage.
  md/raid1,raid10: avoid deadlock during resync/recovery.
  md/bitmap: ensure to load bitmap when creating via sysfs.
  md: don't set md arrays to readonly on shutdown.
  md: allow re-add to failed arrays.
  md/raid5: use atomic_dec_return() instead of atomic_dec() and atomic_read().
  md: Use existed macros instead of numbers
  md/raid5: removed unused 'added_devices' variable.
  ...
2012-03-22 12:29:50 -07:00
Linus Torvalds
9f3938346a Merge branch 'kmap_atomic' of git://github.com/congwang/linux
Pull kmap_atomic cleanup from Cong Wang.

It's been in -next for a long time, and it gets rid of the (no longer
used) second argument to k[un]map_atomic().

Fix up a few trivial conflicts in various drivers, and do an "evil
merge" to catch some new uses that have come in since Cong's tree.

* 'kmap_atomic' of git://github.com/congwang/linux: (59 commits)
  feature-removal-schedule.txt: schedule the deprecated form of kmap_atomic() for removal
  highmem: kill all __kmap_atomic() [swarren@nvidia.com: highmem: Fix ARM build break due to __kmap_atomic rename]
  drbd: remove the second argument of k[un]map_atomic()
  zcache: remove the second argument of k[un]map_atomic()
  gma500: remove the second argument of k[un]map_atomic()
  dm: remove the second argument of k[un]map_atomic()
  tomoyo: remove the second argument of k[un]map_atomic()
  sunrpc: remove the second argument of k[un]map_atomic()
  rds: remove the second argument of k[un]map_atomic()
  net: remove the second argument of k[un]map_atomic()
  mm: remove the second argument of k[un]map_atomic()
  lib: remove the second argument of k[un]map_atomic()
  power: remove the second argument of k[un]map_atomic()
  kdb: remove the second argument of k[un]map_atomic()
  udf: remove the second argument of k[un]map_atomic()
  ubifs: remove the second argument of k[un]map_atomic()
  squashfs: remove the second argument of k[un]map_atomic()
  reiserfs: remove the second argument of k[un]map_atomic()
  ocfs2: remove the second argument of k[un]map_atomic()
  ntfs: remove the second argument of k[un]map_atomic()
  ...
2012-03-21 09:40:26 -07:00
Linus Torvalds
69a7aebcf0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree from Jiri Kosina:
 "It's indeed trivial -- mostly documentation updates and a bunch of
  typo fixes from Masanari.

  There are also several linux/version.h include removals from Jesper."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (101 commits)
  kcore: fix spelling in read_kcore() comment
  constify struct pci_dev * in obvious cases
  Revert "char: Fix typo in viotape.c"
  init: fix wording error in mm_init comment
  usb: gadget: Kconfig: fix typo for 'different'
  Revert "power, max8998: Include linux/module.h just once in drivers/power/max8998_charger.c"
  writeback: fix fn name in writeback_inodes_sb_nr_if_idle() comment header
  writeback: fix typo in the writeback_control comment
  Documentation: Fix multiple typo in Documentation
  tpm_tis: fix tis_lock with respect to RCU
  Revert "media: Fix typo in mixer_drv.c and hdmi_drv.c"
  Doc: Update numastat.txt
  qla4xxx: Add missing spaces to error messages
  compiler.h: Fix typo
  security: struct security_operations kerneldoc fix
  Documentation: broken URL in libata.tmpl
  Documentation: broken URL in filesystems.tmpl
  mtd: simplify return logic in do_map_probe()
  mm: fix comment typo of truncate_inode_pages_range
  power: bq27x00: Fix typos in comment
  ...
2012-03-20 21:12:50 -07:00
Cong Wang
c2e022cb65 dm: remove the second argument of k[un]map_atomic()
Acked-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-20 21:48:28 +08:00
Cong Wang
b2f46e6882 md: remove the second argument of k[un]map_atomic()
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-20 21:48:18 +08:00
majianpeng
ecb178bb2b md: Add judgement bb->unacked_exist in function md_ack_all_badblocks().
If there are no unacked bad blocks, then there is no point searching
for them to acknowledge them.


Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:42 +11:00
NeilBrown
d0962936bf md: fix clearing of the 'changed' flags for the bad blocks list.
In super_1_sync (the first hunk) we need to clear 'changed' before
checking read_seqretry(), otherwise we might race with other code
adding a bad block and so won't retry later.

In md_update_sb (the second hunk), in the case where there is no
metadata (neither persistent nor external), we treat any bad blocks as
an error.  However we need to clear the 'changed' flag before calling
md_ack_all_badblocks, else it won't do anything.

This patch is suitable for -stable release 3.0 and later.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:41 +11:00
NeilBrown
61a0d80ce4 md/bitmap: discard CHUNK_BLOCK_SHIFT macro
Be redefining ->chunkshift as the shift from sectors to chunks rather
than bytes to chunks, we can just use "bitmap->chunkshift" which is
shorter than the macro call, and less indirect.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:41 +11:00
NeilBrown
792a1d4bbf md/bitmap: remove unnecessary indirection when allocating.
These funcitons don't add anything useful except possibly the trace
points, and I don't think they are worth the extra indirection.
So remove them.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:41 +11:00
NeilBrown
5a6c824ebb md/bitmap: remove some pointless locking.
There is nothing gained by holding a lock while we check if a pointer
is NULL or not.  If there could be a race, then it could become NULL
immediately after the unlock - but there is no race here.

So just remove the locking.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:40 +11:00
NeilBrown
278c1ca2f2 md/bitmap: change a 'goto' to a normal 'if' construct.
The use of a goto makes the control flow more obscure here.

So make it a normal:
  if (x) {
     Y;
  }

No functional change.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:40 +11:00
NeilBrown
57148964d9 md/bitmap: move printing of bitmap status to bitmap.c
The part of /proc/mdstat which describes the bitmap should really
be generated by code in bitmap.c.  So move it there.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:40 +11:00
NeilBrown
4ba97dff71 md/bitmap: remove some unused noise from bitmap.h
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:40 +11:00
NeilBrown
006a09a0ae md/raid10 - support resizing some RAID10 arrays.
'resizing' an array in this context means making use of extra
space that has become available in component devices, not adding new
devices.
It also includes shrinking the array to take up less space of
component devices.

This is not supported for array with a 'far' layout.  However
for 'near' and 'offset' layout arrays, adding and removing space at
the end of the devices is easy to support, and this patch provides
that support.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:40 +11:00
NeilBrown
6b740b8d79 md/raid1: handle merge_bvec_fn in member devices.
Currently we don't honour merge_bvec_fn in member devices so if there
is one, we force all requests to be single-page at most.
This is not ideal.

So create a raid1 merge_bvec_fn to check that function in children
as well.

This introduces a small problem.  There is no locking around calls
the ->merge_bvec_fn and subsequent calls to ->make_request.  So a
device added between these could end up getting a request which
violates its merge_bvec_fn.

Currently the best we can do is synchronize_sched().  This will work
providing no preemption happens.  If there is is preemption, we just
have to hope that new devices are largely consistent with old devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:39 +11:00
NeilBrown
050b66152f md/raid10: handle merge_bvec_fn in member devices.
Currently we don't honour merge_bvec_fn in member devices so if there
is one, we force all requests to be single-page at most.
This is not ideal.

So enhance the raid10 merge_bvec_fn to check that function in children
as well.

This introduces a small problem.  There is no locking around calls
the ->merge_bvec_fn and subsequent calls to ->make_request.  So a
device added between these could end up getting a request which
violates its merge_bvec_fn.

Currently the best we can do is synchronize_sched().  This will work
providing no preemption happens.  If there is preemption, we just
have to hope that new devices are largely consistent with old devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:39 +11:00
NeilBrown
ba13da47ff md: add proper merge_bvec handling to RAID0 and Linear.
These personalities currently set a max request size of one page
when any member device has a merge_bvec_fn because they don't
bother to call that function.

This causes extra works in splitting and combining requests.

So make the extra effort to call the merge_bvec_fn when it exists
so that we end up with larger requests out the bottom.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:39 +11:00
NeilBrown
dafb20fa34 md: tidy up rdev_for_each usage.
md.h has an 'rdev_for_each()' macro for iterating the rdevs in an
mddev.  However it uses the 'safe' version of list_for_each_entry,
and so requires the extra variable, but doesn't include 'safe' in the
name, which is useful documentation.

Consequently some places use this safe version without needing it, and
many use an explicity list_for_each entry.

So:
 - rename rdev_for_each to rdev_for_each_safe
 - create a new rdev_for_each which uses the plain
   list_for_each_entry,
 - use the 'safe' version only where needed, and convert all other
   list_for_each_entry calls to use rdev_for_each.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:39 +11:00
NeilBrown
d6b42dcb99 md/raid1,raid10: avoid deadlock during resync/recovery.
If RAID1 or RAID10 is used under LVM or some other stacking
block device, it is possible to enter a deadlock during
resync or recovery.
This can happen if the upper level block device creates
two requests to the RAID1 or RAID10.  The first request gets
processed, blocks recovery and queue requests for underlying
requests in current->bio_list.  A resync request then starts
which will wait for those requests and block new IO.

But then the second request to the RAID1/10 will be attempted
and it cannot progress until the resync request completes,
which cannot progress until the underlying device requests complete,
which are on a queue behind that second request.

So allow that second request to proceed even though there is
a resync request about to start.

This is suitable for any -stable kernel.

Cc: stable@vger.kernel.org
Reported-by: Ray Morris <support@bettercgi.com>
Tested-by: Ray Morris <support@bettercgi.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:38 +11:00
NeilBrown
4474ca42e2 md/bitmap: ensure to load bitmap when creating via sysfs.
When commit 69e51b449d (md/bitmap:  separate out loading a bitmap...)
created bitmap_load, it missed calling it after bitmap_create when a
bitmap is created through the sysfs interface.
So if a bitmap is added this way, we don't allocate memory properly
and can crash.

This is suitable for any -stable release since 2.6.35.
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:37 +11:00
NeilBrown
c744a65c1e md: don't set md arrays to readonly on shutdown.
It seems that with recent kernel, writeback can still be happening
while shutdown is happening, and consequently data can be written
after the md reboot notifier switches all arrays to read-only.
This causes a BUG.

So don't switch them to read-only - just mark them clean and
set 'safemode' to '2' which mean that immediately after any
write the array will be switch back to 'clean'.

This could result in the shutdown happening when array is marked
dirty, thus forcing a resync on reboot.  However if you reboot
without performing a "sync" first, you get to keep both halves.

This is suitable for any stable kernel (though there might be some
conflicts with obvious fixes in earlier kernels).

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:37 +11:00
NeilBrown
dc10c643e8 md: allow re-add to failed arrays.
When an array is failed (some data inaccessible) then there is no
point attempting to add a spare as it could not possibly be recovered.

However that may be value in re-adding a recently removed device.
e.g. if there is a write-intent-bitmap and it is clear, then access
to the data could be restored by this action.

So don't reject a re-add to a failed array for RAID10 and RAID5 (the
only arrays  types that check for a failed array).

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-19 12:46:37 +11:00
majianpeng
41fe75f60b md/raid5: use atomic_dec_return() instead of atomic_dec() and atomic_read().
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-13 11:21:25 +11:00
NeilBrown
9d4c7d8799 md/raid5: removed unused 'added_devices' variable.
commit 908f4fbd26 removed the last user of this variable,
so we should discard it completely.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-13 11:21:21 +11:00
NeilBrown
547414d19f md/raid10: remove unnecessary smp_mb() from end_sync_write
Recent commit 4ca40c2ce0 (md/raid10: Allow replacement device ...)
added an smp_mb in end_sync_write.
This was to close a possible race with raid10_remove_disk.
However there is no such race as it is never attempted to remove a
disk while resync (or recovery) is happening.
so the smp_mb is just noise.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-13 11:21:20 +11:00
NeilBrown
1e3fa9bd50 md/raid5: make sure reshape_position is cleared on error path.
Leaving a valid reshape_position value in place could be confusing.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-13 11:21:18 +11:00
Linus Torvalds
5d0edf2915 Device-mapper fixes for 3.3.
Eight small device-mapper bug fixes.
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Merge tag 'dm-3.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull device-mapper fixes for 3.3 from Alasdair Kergon

Eight small device-mapper bug fixes.

* tag 'dm-3.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm raid: fix flush support
  dm raid: set MD_CHANGE_DEVS when rebuilding
  dm thin metadata: decrement counter after removing mapped block
  dm thin metadata: unlock superblock in init_pmd error path
  dm thin metadata: remove incorrect close_device on creation error paths
  dm flakey: fix crash on read when corrupt_bio_byte not set
  dm io: fix discard support
  dm ioctl: do not leak argv if target message only contains whitespace
2012-03-08 17:21:51 -08:00
Jonathan E Brassow
0ca93de9b7 dm raid: fix flush support
Fix dm-raid flush support.

Both md and dm have support for flush, but the dm-raid target
forgot to set the flag to indicate that flushes should be
passed on.  (Important for data integrity e.g. with writeback cache
enabled.)

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-07 19:09:48 +00:00
Jonathan E Brassow
3aa3b2b2b1 dm raid: set MD_CHANGE_DEVS when rebuilding
The 'rebuild' parameter is used to rebuild individual devices in an
array (e.g. resynchronize a RAID1 device or recalculate a parity device
in higher RAID).  The MD_CHANGE_DEVS flag must be set when this
parameter is given in order to write out the superblocks and make the
change take immediate effect.  The code that handles new devices in
super_load already sets MD_CHANGE_DEVS and 'FirstUse'.  (The 'FirstUse'
flag was being set as a special case for rebuilds in
super_init_validation.)

Add a condition for rebuilds in super_load to take care of both flags
without the special case in 'super_init_validation'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-07 19:09:47 +00:00
Joe Thornber
af63bcb817 dm thin metadata: decrement counter after removing mapped block
Correct the number of mapped sectors shown on a thin device's
status line by decrementing td->mapped_blocks in __remove() each time
a block is removed.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-07 19:09:44 +00:00
Joe Thornber
4469a5f387 dm thin metadata: unlock superblock in init_pmd error path
If dm_sm_disk_create() fails the superblock must be unlocked.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-07 19:09:43 +00:00
Mike Snitzer
1f3db25d8b dm thin metadata: remove incorrect close_device on creation error paths
The __open_device() error paths in __create_thin() and __create_snap()
incorrectly call __close_device() even if td was not initialized by
__open_device().  Remove this.

Also document __open_device() return values, remove a redundant
td->changed = 1 in __create_thin(), and insert an additional
safeguard against creating an already-existing device.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-07 19:09:41 +00:00
Mike Snitzer
1212268fd9 dm flakey: fix crash on read when corrupt_bio_byte not set
The following BUG is hit on the first read that is submitted to a dm
flakey test device while the device is "down" if the corrupt_bio_byte
feature wasn't requested when the device's table was loaded.

Example DM table that will hit this BUG:
0 2097152 flakey 8:0 2048 0 30

This bug was introduced by commit a3998799fb
(dm flakey: add corrupt_bio_byte feature) in v3.1-rc1.

BUG: unable to handle kernel paging request at ffff8801cfce3fff
IP: [<ffffffffa008c233>] corrupt_bio_data+0x6e/0xae [dm_flakey]
PGD 1606063 PUD 0
Oops: 0002 [#1] SMP
...
Call Trace:
 <IRQ>
 [<ffffffffa008c2b5>] flakey_end_io+0x42/0x48 [dm_flakey]
 [<ffffffffa00dca98>] clone_endio+0x54/0xb6 [dm_mod]
 [<ffffffff81130587>] bio_endio+0x2d/0x2f
 [<ffffffff811c819a>] req_bio_endio+0x96/0x9f
 [<ffffffff811c94b9>] blk_update_request+0x1dc/0x3a9
 [<ffffffff812f5ee2>] ? rcu_read_unlock+0x21/0x23
 [<ffffffff811c96a6>] blk_update_bidi_request+0x20/0x6e
 [<ffffffff811c9713>] blk_end_bidi_request+0x1f/0x5d
 [<ffffffff811c978d>] blk_end_request+0x10/0x12
 [<ffffffff8128f450>] scsi_io_completion+0x1e5/0x4b1
 [<ffffffff812882a9>] scsi_finish_command+0xec/0xf5
 [<ffffffff8128f830>] scsi_softirq_done+0xff/0x108
 [<ffffffff811ce284>] blk_done_softirq+0x84/0x98
 [<ffffffff81048d19>] __do_softirq+0xe3/0x1d5
 [<ffffffff8138f83f>] ? _raw_spin_lock+0x62/0x69
 [<ffffffff810997cf>] ? handle_irq_event+0x4c/0x61
 [<ffffffff8139833c>] call_softirq+0x1c/0x30
 [<ffffffff81003b37>] do_softirq+0x4b/0xa3
 [<ffffffff81048a39>] irq_exit+0x53/0xca
 [<ffffffff81398acd>] do_IRQ+0x9d/0xb4
 [<ffffffff81390333>] common_interrupt+0x73/0x73
...

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.1+
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-07 19:09:39 +00:00
Milan Broz
0c535e0d6f dm io: fix discard support
This patch fixes a crash by recognising discards in dm_io.

Currently dm_mirror can send REQ_DISCARD bios if running over a
discard-enabled device and without support in dm_io the system
crashes badly.

BUG: unable to handle kernel paging request at 00800000
IP:  __bio_add_page.part.17+0xf5/0x1e0
...
 bio_add_page+0x56/0x70
 dispatch_io+0x1cf/0x240 [dm_mod]
 ? km_get_page+0x50/0x50 [dm_mod]
 ? vm_next_page+0x20/0x20 [dm_mod]
 ? mirror_flush+0x130/0x130 [dm_mirror]
 dm_io+0xdc/0x2b0 [dm_mod]
...

Introduced in 2.6.38-rc1 by commit 5fc2ffeabb
(dm raid1: support discard).

Signed-off-by: Milan Broz <mbroz@redhat.com>
Cc: stable@kernel.org
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-07 19:09:37 +00:00
Jesper Juhl
902c6a96a7 dm ioctl: do not leak argv if target message only contains whitespace
If 'argc' is zero we jump to the 'out:' label, but this leaks the
(unused) memory that 'dm_split_args()' allocated for 'argv' if the
string being split consisted entirely of whitespace.  Jump to the
'out_argv:' label instead to free up that memory.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-07 19:09:34 +00:00
Linus Torvalds
a2e5f13ce8 3 fixes for md in 3.3-rc
2 relate to the recently added drive replacement.
 
 One causes read error in RAID10 to sometimes be retried indefinitely.
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Merge tag 'md-3.3-fixes' of git://neil.brown.name/md

Pull md fixes from Neil Brown:
 "Three fixes for md in 3.3-rc: Two relate to the recently added drive
  replacement.  One fixes the problem where a read error in RAID10 would
  sometimes be retried indefinitely."

* tag 'md-3.3-fixes' of git://neil.brown.name/md:
  md/raid10: fix assembling of arrays with replacement devices.
  md/raid10: fix handling of error on last working device in array.
  md/raid1: fix buglet in md_raid1_contested.
2012-03-05 16:01:25 -08:00
NeilBrown
7a90484825 md/raid10: fix assembling of arrays with replacement devices.
commit 56a2559bb6 (md/raid10: recognise replacements ...)
changed 'run' to set ->replacement or ->rdev depending on the
'Replacement' status if the device, but it didn't remove the
old unconditional setting of 'rdev'.  So it was largely ineffective.

So remove that now.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-03-06 10:12:45 +11:00
NeilBrown
fae8cc5ed0 md/raid10: fix handling of error on last working device in array.
If we get a read error on the last working device in a RAID10 which
contains the target block, then we don't fail the device (which is
good) but we don't abort retries, which is wrong.
We end up in an infinite loop retrying the read on the one device.

This patch fixes the problem in two places:
1/ in raid10_end_read_request we don't even ask for a retry if this
   was the last usable device.  This is efficient but a little racy
   and will sometimes retry when it should not.

2/ in handle_read_error we are careful to exclude any device from
   retry which we tried to mark as faulty (that might have failed if
   it was the last device).  This is race-free but less efficient.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-02-14 11:10:10 +11:00
NeilBrown
f53e29fc87 md/raid1: fix buglet in md_raid1_contested.
Since we added 'replacement' capability, RAID1 can have twice
as many devices as ->raid_disks indicates.
So md_raid1_congested needs to check that many possible devices,
not just ->raid_disks many.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-02-13 14:24:05 +11:00
Linus Torvalds
4d39aa1b99 Some simple md-related fixes.
1/ two small fixes to ensure we handle an interrupted resync properly.
 2/ avoid loading the bitmap multiple times in dm-raid
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Merge tag 'md-3.3-fixes' of git://neil.brown.name/md

Some simple md-related fixes.

1/ two small fixes to ensure we handle an interrupted resync properly.
2/ avoid loading the bitmap multiple times in dm-raid

* tag 'md-3.3-fixes' of git://neil.brown.name/md:
  md: two small fixes to handling interrupt resync.
  Prevent DM RAID from loading bitmap twice.
2012-02-08 19:06:30 -08:00
NeilBrown
db91ff55bd md: two small fixes to handling interrupt resync.
1/ If a resync is aborted we should record how far we got
 (recovery_cp) the last request that we know has completed
 (->curr_resync_completed) rather than the last request that was
 submitted (->curr_resync).

2/ When a resync aborts we still want to update the metadata with
 any changes, so set MD_CHANGE_DEVS even if we 'skip'.

Signed-off-by: NeilBrown <neilb@suse.de>
2012-02-07 12:01:51 +11:00
Jiri Kosina
972c5ae961 Merge branch 'master' into for-next
Sync with Linus' tree to be able to apply patch to a newer
code (namely drivers/gpu/drm/gma500/psb_intel_lvds.c)
2012-02-03 23:13:05 +01:00
Jesper Juhl
ad075370ba dm-bufio.c: there's no need to include linux/version.h
As 'make versioncheck' points out, drivers/md/dm-bufio.c has no need to include
linux/version.h, so this patch removes the unneeded include.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-02-03 22:38:12 +01:00
Jonathan Brassow
34f8ac6d79 Prevent DM RAID from loading bitmap twice.
The life cycle of a device-mapper target is:
1) create
2) resume
3) suspend
*) possibly repeat from 2
4) destroy

The dm-raid target is unconditionally calling MD's bitmap_load function upon
every resume.  If steps 2 & 3 above are repeated, bitmap_load is called
multiple times.  It is only written to be called once; otherwise, it allocates
new memory for the bitmap (without freeing the old) and incrementing the number
of pages it thinks it has without zeroing first.  This ultimately leads to
access beyond allocated memory and lost memory.

Simply avoiding the bitmap_load call upon resume is not sufficient.  If the
target was suspended while the initial recovery was only partially complete,
it needs to be restarted when the target is resumed.  This is why
'md_wakeup_thread' is called before issuing the 'mddev_resume'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-01-31 09:43:41 +11:00
Linus Torvalds
b3c9dd182e Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block
* 'for-3.3/core' of git://git.kernel.dk/linux-block: (37 commits)
  Revert "block: recursive merge requests"
  block: Stop using macro stubs for the bio data integrity calls
  blockdev: convert some macros to static inlines
  fs: remove unneeded plug in mpage_readpages()
  block: Add BLKROTATIONAL ioctl
  block: Introduce blk_set_stacking_limits function
  block: remove WARN_ON_ONCE() in exit_io_context()
  block: an exiting task should be allowed to create io_context
  block: ioc_cgroup_changed() needs to be exported
  block: recursive merge requests
  block, cfq: fix empty queue crash caused by request merge
  block, cfq: move icq creation and rq->elv.icq association to block core
  block, cfq: restructure io_cq creation path for io_context interface cleanup
  block, cfq: move io_cq exit/release to blk-ioc.c
  block, cfq: move icq cache management to block core
  block, cfq: move io_cq lookup to blk-ioc.c
  block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq
  block, cfq: reorganize cfq_io_context into generic and cfq specific parts
  block: remove elevator_queue->ops
  block: reorder elevator switch sequence
  ...

Fix up conflicts in:
 - block/blk-cgroup.c
	Switch from can_attach_task to can_attach
 - block/cfq-iosched.c
	conflict with now removed cic index changes (we now use q->id instead)
2012-01-15 12:24:45 -08:00
Paolo Bonzini
ec8013bedd dm: do not forward ioctls from logical volumes to the underlying device
A logical volume can map to just part of underlying physical volume.
In this case, it must be treated like a partition.

Based on a patch from Alasdair G Kergon.

Cc: Alasdair G Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-14 15:07:24 -08:00
Linus Torvalds
c086ae4ed9 Two bugfixes for md.
One is a recently introduced regression that affects an unusual
 configuration with a guaranteed BUG_ON.  Has been tagged for -stable.
 The other is minor missing functionality.
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Merge tag 'md-3.3-fixes' of git://neil.brown.name/md

Two bugfixes for md.

One is a recently introduced regression that affects an unusual
configuration with a guaranteed BUG_ON.  Has been tagged for -stable.
The other is minor missing functionality.

* tag 'md-3.3-fixes' of git://neil.brown.name/md:
  md/raid1: perform bad-block tests for WriteMostly devices too.
  md: notify the 'degraded' sysfs attribute on failure.
2012-01-11 18:51:55 -08:00
Martin K. Petersen
b1bd055d39 block: Introduce blk_set_stacking_limits function
Stacking driver queue limits are typically bounded exclusively by the
capabilities of the low level devices, not by the stacking driver
itself.

This patch introduces blk_set_stacking_limits() which has more liberal
metrics than the default queue limits function. This allows us to
inherit topology parameters from bottom devices without manually
tweaking the default limits in each driver prior to calling the stacking
function.

Since there is now a clear distinction between stacking and low-level
devices, blk_set_default_limits() has been modified to carry the more
conservative values that we used to manually set in
blk_queue_make_request().

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-01-11 16:27:11 +01:00
NeilBrown
307729c8bc md/raid1: perform bad-block tests for WriteMostly devices too.
We normally try to avoid reading from write-mostly devices, but when
we do we really have to check for bad blocks and be sure not to
try reading them.

With the current code, best_good_sectors might not get set and that
causes zero-length read requests to be send down which is very
confusing.

This bug was introduced in commit d2eb35acfd and so the patch
is suitable for 3.1.x and 3.2.x

Reported-and-tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Reported-and-tested-by: Art -kwaak- van Breemen <ard@telegraafnet.nl>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org
2012-01-11 08:35:17 +11:00
NeilBrown
f2a371c5e7 md: notify the 'degraded' sysfs attribute on failure.
We currently only 'notify' changes to the 'degraded' attribute
when it decreases, not when it increases.

Notifying on failure is a little awkward as it happen in
interrupt context.
So instead, notify when we remove the failed device from the array,
which is very soon afterwards.

Reported-and-tested-by: Mikhail Balabin <mbalabin@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2012-01-11 08:35:14 +11:00
Linus Torvalds
2943c83322 md update for 3.3
Big change is new hot-replacement.
 A slot in an array can hold 2 devices - one that
 wants-replacement and one that is the replacement.
 Once the replacement is built - either from the
 original or (in the case of errors) from elsewhere,
 the wants-replacement device will be removed.
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Merge tag 'md-3.3' of git://neil.brown.name/md

md update for 3.3

Big change is new hot-replacement.
A slot in an array can hold 2 devices - one that
wants-replacement and one that is the replacement.
Once the replacement is built - either from the
original or (in the case of errors) from elsewhere,
the wants-replacement device will be removed.

* tag 'md-3.3' of git://neil.brown.name/md: (36 commits)
  md/raid1: Mark device want_replacement when we see a write error.
  md/raid1: If there is a spare and a want_replacement device, start replacement.
  md/raid1: recognise replacements when assembling arrays.
  md/raid1: handle activation of replacement device when recovery completes.
  md/raid1: Allow a failed replacement device to be removed.
  md/raid1: Allocate spare to store replacement devices and their bios.
  md/raid1:  Replace use of mddev->raid_disks with conf->raid_disks.
  md/raid10: If there is a spare and a want_replacement device, start replacement.
  md/raid10: recognise replacements when assembling array.
  md/raid10: Allow replacement device to be replace old drive.
  md/raid10: handle recovery of replacement devices.
  md/raid10:  Handle replacement devices during resync.
  md/raid10: writes should get directed to replacement as well as original.
  md/raid10: allow removal of failed replacement devices.
  md/raid10: preferentially read from replacement device if possible.
  md/raid10:  change read_balance to return an rdev
  md/raid10: prepare data structures for handling replacement.
  md/raid5: Mark device want_replacement when we see a write error.
  md/raid5: If there is a spare and a want_replacement device, start replacement.
  md/raid5: recognise replacements when assembling array.
  ...
2012-01-08 13:28:33 -08:00
Al Viro
ff01bb4832 fs: move code out of buffer.c
Move invalidate_bdev, block_sync_page into fs/block_dev.c.  Export
kill_bdev as well, so brd doesn't have to open code it.  Reduce
buffer_head.h requirement accordingly.

Removed a rather large comment from invalidate_bdev, as it looked a bit
obsolete to bother moving.  The small comment replacing it says enough.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:07 -05:00
NeilBrown
19d671695e md/raid1: Mark device want_replacement when we see a write error.
Now that WantReplacement drives are replaced cleanly, mark a drive
as want_replacement when we see a write error.  It might get failed soon so
the WantReplacement flag is irrelevant, but if the write error is recorded
in the bad block log, we still want to activate any spare that might
be available.

Signed-off-by:  NeilBrown <neilb@suse.de>
2011-12-23 10:17:57 +11:00
NeilBrown
7ef449d1ec md/raid1: If there is a spare and a want_replacement device, start replacement.
When attempting to add a spare to a RAID1 array, also consider
adding it as a replacement for a want_replacement device.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:57 +11:00
NeilBrown
c19d57980b md/raid1: recognise replacements when assembling arrays.
If a Replacement is seen, file it as such.

If we see two replacements (or two normal devices) for the one slot,
abort.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:57 +11:00
NeilBrown
8c7a2c2bcf md/raid1: handle activation of replacement device when recovery completes.
When recovery completes ->spare_active is called.
This checks if the replacement is ready and if so it fails
the original.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:57 +11:00
NeilBrown
b014f14c81 md/raid1: Allow a failed replacement device to be removed.
Replacement devices are stored at a different offset, so look
there too.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:56 +11:00
NeilBrown
8f19ccb2fd md/raid1: Allocate spare to store replacement devices and their bios.
In RAID1, a replacement is much like a normal device, so we just
double the size of the relevant arrays and look at all possible
devices for reads and writes.

This means that the array looks like it is now double the size in some
way - we need to be careful about that.
In particular, we checking if the array is still degraded while
creating a recovery request we need to only consider the first 'half'
- i.e. the real (non-replacement) devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:56 +11:00
NeilBrown
301946364e md/raid1: Replace use of mddev->raid_disks with conf->raid_disks.
In general mddev->raid_disks can change unexpectedly while
conf->raid_disks will only change in a very controlled way.  So change
some uses of one to the other.

The use of mddev->raid_disks will not cause actually problems but
this way is more consistent and safer in the long term.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:56 +11:00
NeilBrown
b7044d41b5 md/raid10: If there is a spare and a want_replacement device, start replacement.
When attempting to add a spare to a RAID10 array, also consider
adding it as a replacement for a want_replacement device.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:56 +11:00
NeilBrown
56a2559bb6 md/raid10: recognise replacements when assembling array.
If a Replacement is seen, file it as such.

If we see two replacements (or two normal devices) for the one slot,
abort.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:55 +11:00
NeilBrown
4ca40c2ce0 md/raid10: Allow replacement device to be replace old drive.
When recovery finish and spare_active is called, check for a
replace that might have just become fully synced and mark it
as such, marking the original as failed.

Then when the original is removed, move the replacement into
its position.

This means that 'replacement' and spontaneously become NULL in some
situations.  Make sure we check for those.
It also means that 'rdev' and 'replacement' could appear to be
identical - check for that too.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:55 +11:00
NeilBrown
24afd80d99 md/raid10: handle recovery of replacement devices.
If there is a replacement device, then recover to it,
reading from any drives - maybe the one being replaced, maybe not.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:55 +11:00
NeilBrown
9ad1aefc8a md/raid10: Handle replacement devices during resync.
If we need to resync an array which has replacement devices,
we always write any block checked to every replacement.

If the resync was bitmap-based resync we will then complete the
replacement normally.
If it was a full resync, we mark the replacements as fully recovered
when the resync finishes so no further recovery is needed.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:55 +11:00
NeilBrown
475b0321a4 md/raid10: writes should get directed to replacement as well as original.
When writing, we need to submit two writes, one to the original,
and one to the replacements - if there is a replacement.

If the write to the replacement results in a write error we just
fail the device.  We only try to record write errors to the
original.

This only handles writing new data.  Writing for resync/recovery
will come later.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:55 +11:00
NeilBrown
c8ab903ea9 md/raid10: allow removal of failed replacement devices.
Enhance raid10_remove_disk to be able to remove ->replacement
as well as ->rdev

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:54 +11:00
NeilBrown
abbf098e6e md/raid10: preferentially read from replacement device if possible.
When reading (for array reads, not for recovery etc) we read from the
replacement device if it has recovered far enough.
This requires storing the chosen rdev in the 'r10_bio' so we can make
sure to drop the ref on the right device when the read finishes.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:54 +11:00
NeilBrown
96c3fd1f38 md/raid10: change read_balance to return an rdev
It makes more sense to return an rdev than just an index as
read_balance() gets a reference to the rdev and so returning
the pointer make this more idiomatic.

This will be needed in a future patch when we might return
a 'replacement' rdev instead of the main rdev.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:54 +11:00
NeilBrown
69335ef3bc md/raid10: prepare data structures for handling replacement.
Allow each slot in the RAID10 to have 2 devices, the want_replacement
and the replacement.

Also an r10bio to have 2 bios, and for resync/recovery allocate the
second bio if there are any replacement devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:54 +11:00
NeilBrown
3a6de2924a md/raid5: Mark device want_replacement when we see a write error.
Now that WantReplacement drives are replaced cleanly, mark a drive
as WantReplacement when we see a write error.  It might get failed soon so
the WantReplacement flag is irrelevant, but if the write error is recorded
in the bad block log, we still want to activate any spare that might
be available.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by:  NeilBrown <neilb@suse.de>
2011-12-23 10:17:54 +11:00
NeilBrown
7bfec5f35c md/raid5: If there is a spare and a want_replacement device, start replacement.
When attempting to add a spare to a RAID[456] array, also consider
adding it as a replacement for a want_replacement device.

This requires that common md code attempt hot_add even when the array
is not formally degraded.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:53 +11:00
NeilBrown
17045f52ac md/raid5: recognise replacements when assembling array.
If a Replacement is seen, file it as such.

If we see two replacements (or two normal devices) for the one slot,
abort.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:53 +11:00
NeilBrown
dd054fce88 md/raid5: handle activation of replacement device when recovery completes.
When recovery completes - as reported by a call to ->spare_active,
we clear In_sync on the original and set it on the replacement.

Then when the original gets removed we move the replacement from
'replacement' to 'rdev'.

This could race with other code that is looking at these pointers,
so we use memory barriers and careful ordering to ensure that
a reader might see one device twice, but never no devices.
Then the readers guard against using both devices, which could
only happen when writing.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:53 +11:00
NeilBrown
9a3e1101b8 md/raid5: detect and handle replacements during recovery.
During recovery we want to write to the replacement but not
the original.  So we have two new flags
 - R5_NeedReplace if this stripe has a replacement that needs to
   be written at some stage
 - R5_WantReplace if NeedReplace, and the data is available, and
   a 'sync' has been requested on this stripe.

We also distinguish between 'sync and replace' which need to read
all other devices, and 'replace' which only needs to read the
devices being replaced.

Note that during resync we always write to any replacement device.
It might not need to be written to, but as we don't read to compare,
we have to write to be sure.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:53 +11:00
NeilBrown
977df36255 md/raid5: writes should get directed to replacement as well as original.
When writing, we need to submit two writes, one to the original, and
one to the replacement - if there is a replacement.

If the write to the replacement results in a write error, we just fail
the device.  We only try to record write errors to the original.

When writing for recovery, we shouldn't write to the original.  This
will be addressed in a subsequent patch that generally addresses
recovery.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:53 +11:00
NeilBrown
657e3e4d88 md/raid5: allow removal for failed replacement devices.
Enhance raid5_remove_disk to be able to remove ->replacement
as well as ->rdev.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:52 +11:00
NeilBrown
14a75d3e07 md/raid5: preferentially read from replacement device if possible.
If a replacement device is present and has been recovered far enough,
then use it for reading into the stripe cache.

If we get an error we don't try to repair it, we just fail the device.
A replacement device that gives errors does not sound sensible.

This requires removing the setting of R5_ReadError when we get
a read error during a read that bypasses the cache.  It was probably
a bad idea anyway as we don't know that every block in the read
caused an error, and it could cause ReadError to be set for the
replacement device, which is bad.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:52 +11:00
NeilBrown
995c4275a7 md/raid5: remove redundant bio initialisations.
We current initialise some fields of a bio when preparing a
stripe_head, and again just before submitting the request.

Remove the duplication by only setting the fields that lower level
devices don't touch in raid5_build_block, and only set the changeable
fields in ops_run_io.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:52 +11:00
NeilBrown
ede7ee8b4d md/raid5: raid5.h cleanup
Remove some #defines that are no longer used, and replace some
others with an enum.
And remove an unused field.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:52 +11:00
NeilBrown
671488cc25 md/raid5: allow each slot to have an extra replacement device
Just enhance data structures to record a second device per slot to be
used as a 'replacement' device, replacing the original.
We also have a second bio in each slot in each stripe_head.  This will
only be used when writing to the array - we need to write to both the
original and the replacement at the same time, so will need two bios.

For now, only try using the replacement drive for aligned-reads.
In this case, we prefer the replacement if it has been recovered far
enough, otherwise use the original.

This includes a small enhancement.  Previously we would only do
aligned reads if the target device was fully recovered.  Now we also
do them if it has recovered far enough.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:52 +11:00
NeilBrown
2d78f8c451 md: create externally visible flags for supporting hot-replace.
hot-replace is a feature being added to md which will allow a
device to be replaced without removing it from the array first.

With hot-replace a spare can be activated and recovery can start while
the original device is still in place, thus allowing a transition from
an unreliable device to a reliable device without leaving the array
degraded during the transition.  It can also be use when the original
device is still reliable but it not wanted for some reason.

This will eventually be supported in RAID4/5/6 and RAID10.

This patch adds a super-block flag to distinguish the replacement
device.  If an old kernel sees this flag it will reject the device.

It also adds two per-device flags which are viewable and settable via
sysfs.
   "want_replacement" can be set to request that a device be replaced.
   "replacement" is set to show that this device is replacing another
   device.

The "rd%d" links in /sys/block/mdXx/md only apply to the original
device, not the replacement.  We currently don't make links for the
replacement - there doesn't seem to be a need.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:51 +11:00
NeilBrown
b8321b68d1 md: change hot_remove_disk to take an rdev rather than a number.
Soon an array will be able to have multiple devices with the
same raid_disk number (an original and a replacement).  So removing
a device based on the number won't work.  So pass the actual device
handle instead.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:51 +11:00
NeilBrown
476a7abb9b md: remove test for duplicate device when setting slot number.
When setting the slot number on a device in an active array we
currently check that the number is not already in use.
We then call into the personality's hot_add_disk function
which performs the same test and returns the same error.

Thus the common test is not needed.

As we will shortly be changing some personalities to allow duplicates
in some cases (to support hot-replace), the common test will become
inconvenient.

So remove the common test.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:51 +11:00
NeilBrown
915c420ddf md/bitmap: be more consistent when setting new bits in memory bitmap.
For each active region corresponding to a bit in the bitmap with have
a 14bit counter (and some flags).
This counts
   number of active writes + bit in the on-disk bitmap + delay-needed.

The "delay-needed" is because we always want a delay before clearing a
bit.  So the number here is normally number of active writes plus 2.
If there have been no writes for a while, we drop to 1.
If still no writes we clear the bit and drop to 0.

So for consistency, when setting bit from the on-disk bitmap or by
request from user-space it is best to set the counter to '2' to start
with.

In particular we might also set the NEEDED_MASK flag at this time, and
in all other cases NEEDED_MASK is only set when the counter is 2 or
more.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:51 +11:00
NeilBrown
908f4fbd26 md/raid5: be more thorough in calculating 'degraded' value.
When an array is being reshaped to change the number of devices,
the two halves can be differently degraded.  e.g. one could be
missing a device and the other not.

So we need to be more careful about calculating the 'degraded'
attribute.

Instead of just inc/dec at appropriate times, perform a full
re-calculation examining both possible cases.  This doesn't happen
often so it not a big cost, and we already have most of the code to
do it.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:50 +11:00
NeilBrown
2e61ebbcc4 md/bitmap: daemon_work cleanup.
We have a variable 'mddev' in this function, but repeatedly get the
same value by dereferencing bitmap->mddev.
There is room for simplification here...

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:50 +11:00
NeilBrown
506c9e44a8 md: allow non-privileged uses to GET_*_INFO about raid arrays.
The info is already available in /proc/mdstat and /sys/block in
an accessible form so there is no point in putting a road-block in
the ioctl for information gathering.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 10:17:26 +11:00
NeilBrown
961902c0f8 md/bitmap: It is OK to clear bits during recovery.
commit d0a4bb4927 introduced a
regression which is annoying but fairly harmless.

When writing to an array that is undergoing recovery (a spare
in being integrated into the array), writing to the array will
set bits in the bitmap, but they will not be cleared when the
write completes.

For bits covering areas that have not been recovered yet this is not a
problem as the recovery will clear the bits.  However bits set in
already-recovered region will stay set and never be cleared.
This doesn't risk data integrity.  The only negatives are:
 - next time there is a crash, more resyncing than necessary will
   be done.
 - the bitmap doesn't look clean, which is confusing.

While an array is recovering we don't want to update the
'events_cleared' setting in the bitmap but we do still want to clear
bits that have very recently been set - providing they were written to
the recovering device.

So split those two needs - which previously both depended on 'success'
and always clear the bit of the write went to all devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 09:57:48 +11:00
NeilBrown
60fc13702a md: don't give up looking for spares on first failure-to-add
Before performing a recovery we try to remove any spares that
might not be working, then add any that might have become relevant.

Currently we abort on the first spare that cannot be added.
This is a false optimisation.
It is conceivable that - depending on rules in the personality - a
subsequent spare might be accepted.
Also the loop does other things like count the available spares and
reset the 'recovery_offset' value.

If we abort early these might not happen properly.

So remove the early abort.

In particular if you have an array what is undergoing recovery and
which has extra spares, then the recovery may not restart after as
reboot as the could of 'spares' might end up as zero.

Reported-by: Anssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 09:57:19 +11:00
NeilBrown
30d7a48368 md/raid5: ensure correct assessment of drives during degraded reshape.
While reshaping a degraded array (as when reshaping a RAID0 by first
converting it to a degraded RAID4) we currently get confused about
which devices are in_sync.  In most cases we get it right, but in the
region that is being reshaped we need to treat non-failed devices as
in-sync when we have the data but haven't actually written it out yet.

Reported-by: Adam Kwolek <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 09:57:00 +11:00
NeilBrown
09cd9270ea md/linear: fix hot-add of devices to linear arrays.
commit d70ed2e4fa
broke hot-add to a linear array.
After that commit, metadata if not written to devices until they
have been fully integrated into the array as determined by
saved_raid_disk.  That patch arranged to clear that field after
a recovery completed.

However for linear arrays, there is no recovery - the integration is
instantaneous.  So we need to explicitly clear the saved_raid_disk
field.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-23 09:56:55 +11:00
Adam Kwolek
5d8c71f9e5 md: raid5 crash during degradation
NULL pointer access causes crash in raid5 module.

Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-09 14:26:11 +11:00
NeilBrown
9283d8c5af md/raid5: never wait for bad-block acks on failed device.
Once a device is failed we really want to completely ignore it.
It should go away soon anyway.

In particular the presence of bad blocks on it should not cause us to
block as we won't be trying to write there anyway.

So as soon as we can check if a device is Faulty, do so and pretend
that it is already gone if it is Faulty.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08 16:27:57 +11:00
NeilBrown
8bd2f0a05b md: ensure new badblocks are handled promptly.
When we mark blocks as bad we need them to be acknowledged by the
metadata handler promptly.

For an in-kernel metadata handler that was already being done.  But
for an external metadata handler we need to alert it of the change by
sending a notification through the sysfs file.  This adds that
notification.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08 16:26:08 +11:00
NeilBrown
52c64152a9 md: bad blocks shouldn't cause a Blocked status on a Faulty device.
Once a device is marked Faulty the badblocks - whether acknowledged or
not - become irrelevant.  So they shouldn't cause the device to be
marked as Blocked.

Without this patch, a process might write "-blocked" to clear the
Blocked status, but while that will correctly fail the device, it
won't remove the apparent 'blocked' status.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08 16:22:48 +11:00
NeilBrown
af8a24347f md: take a reference to mddev during sysfs access.
When we are accessing an mddev via sysfs we know that the
mddev cannot disappear because it has an embedded kobj which
is refcounted by sysfs.
And we also take the mddev_lock.
However this is not enough.

The final mddev_put could have been called and the
mddev_delayed_delete is waiting for sysfs to let go so it can destroy
the kobj and mddev.
In this state there are a lot of changes that should not be attempted.

To to guard against this we:
 - initialise mddev->all_mddevs in on last put so the state can be
   easily detected.
 - in md_attr_show and md_attr_store, check ->all_mddevs under
   all_mddevs_lock and mddev_get the mddev if it still appears to
   be active.

This means that if we get to sysfs as the mddev is being deleted we
will get -EBUSY.

rdev_attr_store and rdev_attr_show are similar but already have
sufficient protection.  They check that rdev->mddev still points to
mddev after taking mddev_lock.  As this is cleared  before delayed
removal which can only be requested under the mddev_lock, this
ensure the rdev and mddev are still alive.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08 15:49:46 +11:00
NeilBrown
1d23f178d5 md: refine interpretation of "hold_active == UNTIL_IOCTL".
We like md devices to disappear when they really are not needed.
However it is not possible to tell from the current state whether it
is needed or not.  We can only tell from recent history of changes.

In particular immediately after we create an md device it looks very
similar to immediately after we have finished with it.

So we always preserve a newly created md device until something
significant happens.  This state is stored in 'hold_active'.

The normal case is to keep it until an ioctl happens, as that will
normally either activate it, or explicitly de-activate it.  If it
doesn't then it was probably created by mistake and it is now time to
get rid of it.

We can also modify an array via sysfs (instead of via ioctl) and we
currently treat any change via sysfs like an ioctl as a sign that if
it now isn't more active, it should be destroyed.
However this is not appropriate as changes made via sysfs are more
gradual so we should look for a more definitive change.

So this patch only clears 'hold_active' from UNTIL_IOCTL to clear when
the array_state is changed via sysfs.  Other changes via sysfs
are ignored.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-12-08 15:49:12 +11:00
NeilBrown
7c8f424798 md/lock: ensure updates to page_attrs are properly locked.
Page attributes are set using __set_bit rather than set_bit as
it normally called under a spinlock so the extra atomicity is not
needed.

However there are two places where we might set or clear page
attributes without holding the spinlock.
So add the spinlock in those cases.

This might be the cause of occasional reports that bits a aren't
getting clear properly - theory is that BITMAP_PAGE_PENDING gets lost
when BITMAP_PAGE_NEEDWRITE is set or cleared.  This is an
inconvenience, not a threat to data safety.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-11-23 10:18:52 +11:00
Dan Williams
257a4b42af md/raid5: STRIPE_ACTIVE has lock semantics, add barriers
All updates that occur under STRIPE_ACTIVE should be globally visible
when STRIPE_ACTIVE clears.  test_and_set_bit() implies a barrier, but
clear_bit() does not.

This is suitable for 3.1-stable.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2011-11-08 16:22:06 +11:00
NeilBrown
9a3f530f39 md/raid5: abort any pending parity operations when array fails.
When the number of failed devices exceeds the allowed number
we must abort any active parity operations (checks or updates) as they
are no longer meaningful, and can lead to a BUG_ON in
handle_parity_checks6.

This bug was introduce by commit 6c0069c0ae
in 2.6.29.

Reported-by: Manish Katiyar <mkatiyar@gmail.com>
Tested-by: Manish Katiyar <mkatiyar@gmail.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2011-11-08 16:22:01 +11:00
Stephen Rothwell
a84450604d device-mapper: using EXPORT_SYBOL in dm-space-map-checker.c needs export.h
Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-07 10:29:10 -08:00
Stephen Rothwell
6f66263f8e device-mapper: dm-bufio.c needs to include module.h
since it uses the module facilities.

Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-07 10:29:10 -08:00
Paul Gortmaker
1944ce60fe drivers/md: change module.h -> export.h in persistent-data/dm-*
For the files which are not themselves modular, we can change
them to include only the smaller export.h since all they are
doing is looking for EXPORT_SYMBOL.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-07 10:29:09 -08:00
Linus Torvalds
32aaeffbd4 Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include <linux/module.h>
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include <linux/module.h>
  net: sch_generic remove redundant use of <linux/module.h>
  net: inet_timewait_sock doesnt need <linux/module.h>
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h
2011-11-06 19:44:47 -08:00
Linus Torvalds
b4fdcb02f1 Merge branch 'for-3.2/core' of git://git.kernel.dk/linux-block
* 'for-3.2/core' of git://git.kernel.dk/linux-block: (29 commits)
  block: don't call blk_drain_queue() if elevator is not up
  blk-throttle: use queue_is_locked() instead of lockdep_is_held()
  blk-throttle: Take blkcg->lock while traversing blkcg->policy_list
  blk-throttle: Free up policy node associated with deleted rule
  block: warn if tag is greater than real_max_depth.
  block: make gendisk hold a reference to its queue
  blk-flush: move the queue kick into
  blk-flush: fix invalid BUG_ON in blk_insert_flush
  block: Remove the control of complete cpu from bio.
  block: fix a typo in the blk-cgroup.h file
  block: initialize the bounce pool if high memory may be added later
  block: fix request_queue lifetime handling by making blk_queue_cleanup() properly shutdown
  block: drop @tsk from attempt_plug_merge() and explain sync rules
  block: make get_request[_wait]() fail if queue is dead
  block: reorganize throtl_get_tg() and blk_throtl_bio()
  block: reorganize queue draining
  block: drop unnecessary blk_get/put_queue() in scsi_cmd_ioctl() and blk_get_tg()
  block: pass around REQ_* flags instead of broken down booleans during request alloc/free
  block: move blk_throtl prototypes to block/blk.h
  block: fix genhd refcounting in blkio_policy_parse_and_set()
  ...

Fix up trivial conflicts due to "mddev_t" -> "struct mddev" conversion
and making the request functions be of type "void" instead of "int" in
 - drivers/md/{faulty.c,linear.c,md.c,md.h,multipath.c,raid0.c,raid1.c,raid10.c,raid5.c}
 - drivers/staging/zram/zram_drv.c
2011-11-04 17:06:58 -07:00
Linus Torvalds
43672a0784 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/linux-dm
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/linux-dm:
  dm: raid fix device status indicator when array initializing
  dm log userspace: add log device dependency
  dm log userspace: fix comment hyphens
  dm: add thin provisioning target
  dm: add persistent data library
  dm: add bufio
  dm: export dm get md
  dm table: add immutable feature
  dm table: add always writeable feature
  dm table: add singleton feature
  dm kcopyd: add dm_kcopyd_zero to zero an area
  dm: remove superfluous smp_mb
  dm: use local printk ratelimit
  dm table: propagate non rotational flag
2011-11-02 17:02:37 -07:00
Paul Gortmaker
daaa5f7cbe md: Add in export.h for files using EXPORT_SYMBOL
These files were getting the defines for EXPORT_SYMBOL because
device.h was including module.h.  But we are going to put an
end to that.  So add the proper export.h include now.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:19 -04:00
Paul Gortmaker
056075c764 md: Add module.h to all files using it implicitly
A pending cleanup will mean that module.h won't be implicitly
everywhere anymore.  Make sure the modular drivers in md dir
are actually calling out for <module.h> explicitly in advance.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:18 -04:00
Linus Torvalds
571109f536 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  md/raid10:  Fix bug when activating a hot-spare.
2011-10-31 15:21:29 -07:00
Jonathan E Brassow
2e727c3ca1 dm: raid fix device status indicator when array initializing
When devices in a RAID array are not in-sync, they are supposed to be
reported as such in the status output as an 'a' character, which means
"alive, but not in-sync".  But when the entire array is rebuilt 'A' is
being used, which is incorrect.  This patch corrects this to 'a'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:26 +00:00
Jonathan E Brassow
5a25f0eb70 dm log userspace: add log device dependency
Allow userspace dm log implementations to register their log device so it
is no longer missing from the list of device dependencies.

When device mapper targets use a device they normally call dm_get_device
which includes it in the device list returned to userspace applications
such as LVM through the DM_TABLE_DEPS ioctl.  Userspace log devices
don't use dm_get_device as userspace opens them so they are missing from
the list of dependencies.

This patch extends the DM_ULOG_CTR operation to allow userspace to
respond with the name of the log device (if appropriate) to be
registered via 'dm_get_device'.  DM_ULOG_REQUEST_VERSION is incremented.

This is backwards compatible.  If the kernel and userspace log server
have both been updated, the new information will be passed down to the
kernel and the device will be registered.  If the kernel is new, but
the log server is old, the log server will not pass down any device
information and the kernel will simply bypass the device registration
as before.  If the kernel is old but the log server is new, the log
server will see the old version number and not pass the device info.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:24 +00:00
Jonathan Brassow
b89544575d dm log userspace: fix comment hyphens
Fix comments: clustered-disk needs a hyphen not an underscore.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:22 +00:00
Joe Thornber
991d9fa02d dm: add thin provisioning target
Initial EXPERIMENTAL implementation of device-mapper thin provisioning
with snapshot support.  The 'thin' target is used to create instances of
the virtual devices that are hosted in the 'thin-pool' target.  The
thin-pool target provides data sharing among devices.  This sharing is
made possible using the persistent-data library in the previous patch.

The main highlight of this implementation, compared to the previous
implementation of snapshots, is that it allows many virtual devices to
be stored on the same data volume, simplifying administration and
allowing sharing of data between volumes (thus reducing disk usage).

Another big feature is support for arbitrary depth of recursive
snapshots (snapshots of snapshots of snapshots ...).  The previous
implementation of snapshots did this by chaining together lookup tables,
and so performance was O(depth).  This new implementation uses a single
data structure so we don't get this degradation with depth.

For further information and examples of how to use this, please read
Documentation/device-mapper/thin-provisioning.txt

Signed-off-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:21:18 +00:00
Joe Thornber
3241b1d3e0 dm: add persistent data library
The persistent-data library offers a re-usable framework for the storage
and management of on-disk metadata in device-mapper targets.

It's used by the thin-provisioning target in the next patch and in an
upcoming hierarchical storage target.

For further information, please read
Documentation/device-mapper/persistent-data.txt

Signed-off-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:19:11 +00:00
Mikulas Patocka
95d402f057 dm: add bufio
The dm-bufio interface allows you to do cached I/O on devices,
holding recently-read blocks in memory and performing delayed writes.

We don't use buffer cache or page cache already present in the kernel, because:
* we need to handle block sizes larger than a page
* we can't allocate memory to perform reads or we'd have deadlocks

Currently, when a cache is required, we limit its size to a fraction of
available memory.  Usage can be viewed and changed in
/sys/module/dm_bufio/parameters/ .

The first user is thin provisioning, but more dm users are planned.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:19:09 +00:00
Alasdair G Kergon
3cf2e4ba74 dm: export dm get md
Export dm_get_md() for the new thin provisioning target to use.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:19:06 +00:00
Alasdair G Kergon
36a0456fbf dm table: add immutable feature
Introduce DM_TARGET_IMMUTABLE to indicate that the target type cannot be mixed
with any other target type, and once loaded into a device, it cannot be
replaced with a table containing a different type.

The thin provisioning pool device will use this.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:19:04 +00:00
Alasdair G Kergon
cc6cbe141a dm table: add always writeable feature
Add a target feature flag DM_TARGET_ALWAYS_WRITEABLE to indicate that a target
does not support read-only mode.

The initial implementation of the thin provisioning target uses this.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:19:02 +00:00
Alasdair G Kergon
3791e2fc0e dm table: add singleton feature
Introduce the concept of a singleton table which contains exactly one target.

If a target type sets the DM_TARGET_SINGLETON feature bit device-mapper
will ensure that any table that includes that target contains no others.

The thin provisioning pool target uses this.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:19:00 +00:00
Mikulas Patocka
7f06965390 dm kcopyd: add dm_kcopyd_zero to zero an area
This patch introduces dm_kcopyd_zero() to make it easy to use
kcopyd to write zeros into the requested areas instead
instead of copying.  It is implemented by passing a NULL
copying source to dm_kcopyd_copy().

The forthcoming thin provisioning target uses this.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:18:58 +00:00
Namhyung Kim
fbdc86f3bd dm: remove superfluous smp_mb
Since set_current_state() contains a memory barrier in it,
an additional barrier isn't needed.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:18:56 +00:00
Namhyung Kim
71a16736a1 dm: use local printk ratelimit
printk_ratelimit() shares global ratelimiting state with all
other subsystems, so its usage is discouraged. Instead,
define and use dm's local state.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:18:54 +00:00
Mandeep Singh Baines
4693c9668f dm table: propagate non rotational flag
Allow QUEUE_FLAG_NONROT to propagate up the device stack if all
underlying devices are non-rotational.  Tools like ureadahead will
schedule IOs differently based on the rotational flag.

With this patch, I see boot time go from 7.75 s to 7.46 s on my device.

Suggested-by: J. Richard Barnette <jrbarnette@chromium.org>
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: dm-devel@redhat.com
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-31 20:18:50 +00:00
NeilBrown
7fcc7c8acf md/raid10: Fix bug when activating a hot-spare.
This is a fairly serious bug in RAID10.

When a RAID10 array is degraded and a hot-spare is activated, the
spare does not take up the empty slot, but rather replaces the first
working device.
This is likely to make the array non-functional.   It would normally
be possible to recover the data, but that would need care and is not
guaranteed.

This bug was introduced in commit
   2bb77736ae
which first appeared in 3.1.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-31 12:59:44 +11:00
Linus Torvalds
c3ae1f3356 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (34 commits)
  md: Fix some bugs in recovery_disabled handling.
  md/raid5: fix bug that could result in reads from a failed device.
  lib/raid6: Fix filename emitted in generated code
  md.c: trivial comment fix
  MD: Allow restarting an interrupted incremental recovery.
  md: clear In_sync bit on devices added to an active array.
  md: add proper write-congestion reporting to RAID1 and RAID10.
  md: rename "mdk_personality" to "md_personality"
  md/bitmap remove fault injection options.
  md/raid5: typedef removal: raid5_conf_t -> struct r5conf
  md/raid1: typedef removal: conf_t -> struct r1conf
  md/raid10: typedef removal: conf_t -> struct r10conf
  md/raid0: typedef removal: raid0_conf_t -> struct r0conf
  md/multipath: typedef removal: multipath_conf_t -> struct mpconf
  md/linear: typedef removal: linear_conf_t -> struct linear_conf
  md/faulty: remove typedef: conf_t -> struct faulty_conf
  md/linear: remove typedefs: dev_info_t -> struct dev_info
  md: remove typedefs: mirror_info_t -> struct mirror_info
  md: remove typedefs: r10bio_t -> struct r10bio and r1bio_t -> struct r1bio
  md: remove typedefs: mdk_thread_t -> struct md_thread
  ...
2011-10-26 21:39:42 +02:00
NeilBrown
d890fa2b05 md: Fix some bugs in recovery_disabled handling.
In 3.0 we changed the way recovery_disabled was handle so that instead
of testing against zero, we test an mddev-> value against a conf->
value.
Two problems:
  1/ one place in raid1 was missed and still sets to '1'.
  2/ We didn't explicitly set the conf-> value at array creation
     time.
     It defaulted to '0' just like the mddev value does so they
     could appear equal and thus disable recovery.
     This did not affect normal 'md' as it calls bind_rdev_to_array
     which changes the mddev value.  However the dmraid interface
     doesn't call this and so doesn't change ->recovery_disabled; so at
     array start all recovery is incorrectly disabled.

So initialise the 'conf' value to one less that the mddev value, so
the will only be the same when explicitly set that way.

Reported-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown  <neilb@suse.de>
2011-10-26 11:54:39 +11:00
NeilBrown
355840e7a7 md/raid5: fix bug that could result in reads from a failed device.
This bug was introduced in 415e72d034
which was in 2.6.36.

There is a small window of time between when a device fails and when
it is removed from the array.  During this time we might still read
from it, but we won't write to it - so it is possible that we could
read stale data.

We didn't need the test of 'Faulty' before because the test on
In_sync is sufficient.  Since we started allowing reads from the early
part of non-In_sync devices we need a test on Faulty too.

This is suitable for any kernel from 2.6.36 onwards, though the patch
might need a bit of tweaking in 3.0 and earlier.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-26 10:31:04 +11:00
Tao Ma
9562ad9ab3 block: Remove the control of complete cpu from bio.
bio originally has the functionality to set the complete cpu, but
it is broken.

Chirstoph said that "This code is unused, and from the all the
discussions lately pretty obviously broken.  The only thing keeping
it serves is creating more confusion and possibly more bugs."

And Jens replied with "We can kill bio_set_completion_cpu(). I'm fine
with leaving cpu control to the request based drivers, they are the
only ones that can toggle the setting anyway".

So this patch tries to remove all the work of controling complete cpu
from a bio.

Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-10-24 16:11:30 +02:00
Alasdair G Kergon
d136f2efdf dm kcopyd: fix job_pool leak
Fix memory leak introduced by commit a6e50b409d
(dm snapshot: skip reading origin when overwriting complete chunk).

When allocating a set of jobs from kc->job_pool, job->master_job must be
set (to point to itself) so that the mempool item gets freed when the
master_job completes.

master_job was introduced by commit c6ea41fbbe
(dm kcopyd: preallocate sub jobs to avoid deadlock)

Reported-by: Michael Leun <ml@newton.leun.net>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-10-23 20:55:17 +01:00
Jens Axboe
5c04b426f2 Merge branch 'v3.1-rc10' into for-3.2/core
Conflicts:
	block/blk-core.c
	include/linux/blkdev.h

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-10-19 14:30:42 +02:00
Chris Dunlop
751e67ca2e md.c: trivial comment fix
Trivial comment fix

Signed-off-by: Chris Dunlop <chris@onthe.net.au>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-19 17:15:15 +11:00
Andrei Warkentin
d70ed2e4fa MD: Allow restarting an interrupted incremental recovery.
If an incremental recovery was interrupted, a subsequent
re-add will result in a full recovery, even though an
incremental should be possible (seen with raid1).

Solve this problem by not updating the superblock on the
recovering device until array is not degraded any longer.

Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrei Warkentin <andreiw@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-18 12:16:48 +11:00
NeilBrown
d30519fc59 md: clear In_sync bit on devices added to an active array.
When we add a device to an active array it can be meaningful to set
the 'insync' flag.  This indicates that the device is in-sync with the
array except for locations recorded in the bitmap.
A bitmap-based recovery can then bring it completely in-sync.

Internally we move that flag to 'saved_raid_disk' but forgot to clear
In_sync like we do in add_new_disk.

So clear In_sync after moving its value to saved_raid_disk.

Reported-by: Andrei Warkentin <andreiw@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-18 12:13:47 +11:00
NeilBrown
34db0cd60f md: add proper write-congestion reporting to RAID1 and RAID10.
RAID1 and RAID10 handle write requests by queuing them for handling by
a separate thread.  This is because when a write-intent-bitmap is
active we might need to update the bitmap first, so it is good to
queue a lot of writes, then do one big bitmap update for them all.

However writeback request devices to appear to be congested after a
while so it can make some guesstimate of throughput.  The infinite
queue defeats that (note that RAID5 has already has a finite queue so
it doesn't suffer from this problem).

So impose a limit on the number of pending write requests.  By default
it is 1024 which seems to be generally suitable.  Make it configurable
via module option just in case someone finds a regression.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:50:01 +11:00
NeilBrown
84fc4b56db md: rename "mdk_personality" to "md_personality"
"mdk" doesn't mean anything any more.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:49:58 +11:00
NeilBrown
29d3247ea2 md/bitmap remove fault injection options.
These are too hard to use to be much more than noise.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:49:56 +11:00
NeilBrown
d1688a6d55 md/raid5: typedef removal: raid5_conf_t -> struct r5conf
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:49:52 +11:00
NeilBrown
e809636047 md/raid1: typedef removal: conf_t -> struct r1conf
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:49:05 +11:00
NeilBrown
e879a8793f md/raid10: typedef removal: conf_t -> struct r10conf
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:49:02 +11:00
NeilBrown
e373ab1091 md/raid0: typedef removal: raid0_conf_t -> struct r0conf
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:48:59 +11:00
NeilBrown
69724e28ca md/multipath: typedef removal: multipath_conf_t -> struct mpconf
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:48:57 +11:00
NeilBrown
e849b9381f md/linear: typedef removal: linear_conf_t -> struct linear_conf
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:48:54 +11:00
NeilBrown
8f1ae43dd2 md/faulty: remove typedef: conf_t -> struct faulty_conf
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:48:52 +11:00
NeilBrown
a71207713a md/linear: remove typedefs: dev_info_t -> struct dev_info
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:48:49 +11:00
NeilBrown
0f6d02d580 md: remove typedefs: mirror_info_t -> struct mirror_info
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:48:46 +11:00
NeilBrown
9f2c9d12bc md: remove typedefs: r10bio_t -> struct r10bio and r1bio_t -> struct r1bio
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:48:43 +11:00
NeilBrown
2b8bf3451d md: remove typedefs: mdk_thread_t -> struct md_thread
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:48:23 +11:00
NeilBrown
fd01b88c75 md: remove typedefs: mddev_t -> struct mddev
Having mddev_t and 'struct mddev_s' is ugly and not preferred

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:47:53 +11:00
NeilBrown
3cb0300200 md: removing typedefs: mdk_rdev_t -> struct md_rdev
The typedefs are just annoying. 'mdk' probably refers to 'md_k.h'
which used to be an include file that defined this thing.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-11 16:45:26 +11:00
NeilBrown
50de8df4ab md/raid0: convert some printks to pr_debug.
When md assembles a RAID0 array it prints out lots of info which
is really just for debugging, so convert that to pr_debug.
It also prints out the resulting configuration which could be
interesting, so keep that as 'printk' but tidy it up a bit.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:23:22 +11:00
NeilBrown
36a4e1fe0f md: remove PRINTK and dprintk debugging and use pr_debug
Being able to dynamically enable these make them much more useful.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:23:17 +11:00
NeilBrown
bdc04e6b15 md: remove some old DEBUGging code.
This code is not really helpful and is hard to maintain, so just
discard it.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:23:04 +11:00
NeilBrown
db298e1946 md/raid5: convert to macros into inline functions.
More type-safety.  Easier to read.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:23:00 +11:00
NeilBrown
0fc280f606 md/raid1/ avoid bio search in end_sync_read()
We know which device we just read from so we don't need to
search the bios to find out.  Just use ->read_disk.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:22:55 +11:00
Namhyung Kim
ba3ae3bee3 md/raid1: factor out common bio handling code
When normal-write and sync-read/write bio completes, we should
find out the disk number the bio belongs to. Factor those common
code out to a separate function.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:22:53 +11:00
NeilBrown
e4f869d9de md/raid5: remove pointless NULL test.
In the 'abort' branch of run(), 'conf' cannot possibly be NULL,
so remove the test.

Reported-by: Zdenek Kabelac <zdenek.kabelac@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:22:49 +11:00
NeilBrown
ce550c2059 md/raid1: add documentation to r1_private_data_s data structure.
There wasn't much and it is inconsistent.
Also rearrange fields to keep related fields together.

Reported-by: Aapo Laine <aapo.laine@shiftmail.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-10-07 14:22:33 +11:00
Linus Torvalds
6367f1775e Merge branch 'for-linus' of http://people.redhat.com/agk/git/linux-dm
* 'for-linus' of http://people.redhat.com/agk/git/linux-dm:
  dm crypt: always disable discard_zeroes_data
  dm: raid fix write_mostly arg validation
  dm table: avoid crash if integrity profile changes
  dm: flakey fix corrupt_bio_byte error path
2011-10-06 08:31:47 -07:00
Milan Broz
983c7db347 dm crypt: always disable discard_zeroes_data
If optional discard support in dm-crypt is enabled, discards requests
bypass the crypt queue and blocks of the underlying device are discarded.
For the read path, discarded blocks are handled the same as normal
ciphertext blocks, thus decrypted.

So if the underlying device announces discarded regions return zeroes,
dm-crypt must disable this flag because after decryption there is just
random noise instead of zeroes.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-09-25 23:26:21 +01:00
Jonthan Brassow
8232480944 dm: raid fix write_mostly arg validation
Fix off-by-one error in validation of write_mostly.

The user-supplied value given for the 'write_mostly' argument must be an
index starting at 0.  The validation of the supplied argument failed to
check for 'N' ('>' vs '>='), which would have caused an access beyond the
end of the array.

Reported-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-09-25 23:26:19 +01:00
Mike Snitzer
876fbba1db dm table: avoid crash if integrity profile changes
Commit a63a5cf (dm: improve block integrity support) introduced a
two-phase initialization of a DM device's integrity profile.  This
patch avoids dereferencing a NULL 'template_disk' pointer in
blk_integrity_register() if there is an integrity profile mismatch in
dm_table_set_integrity().

This can occur if the integrity profiles for stacked devices in a DM
table are changed between the call to dm_table_prealloc_integrity() and
dm_table_set_integrity().

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org # 2.6.39
2011-09-25 23:26:17 +01:00
Mike Snitzer
68e58a294f dm: flakey fix corrupt_bio_byte error path
If no arguments were provided to the corrupt_bio_byte feature an error
should be returned immediately.

Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-09-25 23:26:15 +01:00
Daniel P. Berrange
2dba6a911c md: don't delay reboot by 1 second if no MD devices exist
The md_notify_reboot() method includes a call to mdelay(1000),
to deal with "exotic SCSI devices" which are too volatile on
reboot. The delay is unconditional. Even if the machine does
not have any block devices, let alone MD devices, the kernel
shutdown sequence is slowed down.

1 second does not matter much with physical hardware, but with
certain virtualization use cases any wasted time in the bootup
& shutdown sequence counts for alot.

* drivers/md/md.c: md_notify_reboot() - only impose a delay if
  there was at least one MD device to be stopped during reboot

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-23 19:54:04 +10:00
Wang Sheng-Hui
7e84152626 trival: md_k.h should be md.h in the beginning comment of file md.h
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-21 15:37:46 +10:00
NeilBrown
2585f3ef8c md/bitmap: improve handling of 'allclean'.
The 'allclean' flag is used to cache the fact that there is nothing to
do, so we can avoid waking up and scanning the bitmap regularly.

The two sorts of pages that might need the attention of the bitmap
daemon are BITMAP_PAGE_PENDING and BITMAP_PAGE_NEEDWRITE pages.

So make sure allclean reflects exactly when there are none of those.
So:
  set it before scanning all pages with either bit set.
  clear it whenever these bits are set
  clear it when we desire not to clear one of these bits.
  don't clear it any other time.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-21 15:37:46 +10:00
NeilBrown
5a537df44d md/bitmap: rename and tidy up BITMAP_PAGE_CLEAN
The flag 'BITMAP_PAGE_CLEAN' has a confusing name as it doesn't mean
that the page is clean, but rather that there are counters in the page
which allow bits in the bitmap to be cleared - i.e. maybe cleaning can
happen.

So change it to BITMAP_PAGE_PENDING and fix some irregularities:
 - Don't set it in bitmap_init_from_disk as bitmap_set_memory_bits
   sets it when needed
 - in bitmap_daemon_work, if we find a counter that is '1', but
   need_sync is set, then set BITMAP_PAGE_PENDING again (it was
   recently cleared) to ensure we don't forget about this bit.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-21 15:37:46 +10:00
NeilBrown
01f96c0a99 md: Avoid waking up a thread after it has been freed.
Two related problems:

1/ some error paths call "md_unregister_thread(mddev->thread)"
   without subsequently clearing ->thread.  A subsequent call
   to mddev_unlock will try to wake the thread, and crash.

2/ Most calls to md_wakeup_thread are protected against the thread
   disappeared either by:
      - holding the ->mutex
      - having an active request, so something else must be keeping
        the array active.
   However mddev_unlock calls md_wakeup_thread after dropping the
   mutex and without any certainty of an active request, so the
   ->thread could theoretically disappear.
   So we need a spinlock to provide some protections.

So change md_unregister_thread to take a pointer to the thread
pointer, and ensure that it always does the required locking, and
clears the pointer properly.

Reported-by: "Moshe Melnikov" <moshe@zadarastorage.com>
Signed-off-by: NeilBrown <neilb@suse.de>
cc: stable@kernel.org
2011-09-21 15:30:20 +10:00
Christoph Hellwig
5a7bbad27a block: remove support for bio remapping from ->make_request
There is very little benefit in allowing to let a ->make_request
instance update the bios device and sector and loop around it in
__generic_make_request when we can archive the same through calling
generic_make_request from the driver and letting the loop in
generic_make_request handle it.

Note that various drivers got the return value from ->make_request and
returned non-zero values for errors.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-09-12 12:12:01 +02:00
Jens Axboe
c20e8de27f block: rename __make_request() to blk_queue_bio()
Now that it's exported, lets put it in a more sane namespace.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-09-12 12:08:31 +02:00
Christoph Hellwig
166e1f901b block: export __make_request
Avoid the hacks need for request based device mappers currently by simply
exporting the symbol instead of trying to get it through the back door.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-09-12 12:08:27 +02:00
NeilBrown
27a7b260f7 md: Fix handling for devices from 2TB to 4TB in 0.90 metadata.
0.90 metadata uses an unsigned 32bit number to count the number of
kilobytes used from each device.
This should allow up to 4TB per device.
However we multiply this by 2 (to get sectors) before casting to a
larger type, so sizes above 2TB get truncated.

Also we allow rdev->sectors to be larger than 4TB, so it is possible
for the array to be resized larger than the metadata can handle.
So make sure rdev->sectors never exceeds 4TB when 0.90 metadata is in
used.

Also the sanity check at the end of super_90_load should include level
1 as it used ->size too. (RAID0 and Linear don't use ->size at all).

Reported-by: Pim Zandbergen <P.Zandbergen@macroscoop.nl>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-10 17:21:28 +10:00
NeilBrown
079fa166a2 md/raid1,10: Remove use-after-free bug in make_request.
A single request to RAID1 or RAID10 might result in multiple
requests if there are known bad blocks that need to be avoided.

To detect if we need to submit another write request we test:
 	if (sectors_handled < (bio->bi_size >> 9)) {

However this is after we call **_write_done() so the 'bio' no longer
belongs to us - the writes could have completed and the bio freed.

So move the **_write_done call until after the test against
bio->bi_size.

This addresses https://bugzilla.kernel.org/show_bug.cgi?id=41862

Reported-by: Bruno Wolff III <bruno@wolff.to>
Tested-by: Bruno Wolff III <bruno@wolff.to>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-10 17:21:23 +10:00
NeilBrown
19d5f834d6 md/raid10: unify handling of write completion.
A write can complete at two different places:
1/ when the last member-device write completes, through
   raid10_end_write_request
2/ in make_request() when we remove the initial bias from ->remaining.

These two should do exactly the same thing and the comment says they
do, but they don't.

So factor the correct code out into a function and call it in both
places.  This makes the code much more similar to RAID1.

The difference is only significant if there is an error, and they
usually take a while, so it is unlikely that there will be an error
already when make_request is completing, so this is unlikely to cause
real problems.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-09-10 17:21:17 +10:00
NeilBrown
43220aa0f2 md/raid5: fix a hang on device failure.
Waiting for a 'blocked' rdev to become unblocked in the raid5d thread
cannot work with internal metadata as it is the raid5d thread which
will clear the blocked flag.
This wasn't a problem in 3.0 and earlier as we only set the blocked
flag when external metadata was used then.
However we now set it always, so we need to be more careful.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-31 12:49:14 +10:00
NeilBrown
7da64a0abc md: fix clearing of 'blocked' flag in the presence of bad blocks.
When the 'blocked' flag on a device is cleared while there are
unacknowledged bad blocks we must fail the device.  This is needed for
backwards compatability of the interface.

The code currently uses the wrong test for "unacknowledged bad blocks
exist".  Change it to the right test.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-30 16:20:17 +10:00
NeilBrown
1b6afa1758 md/linear: avoid corrupting structure while waiting for rcu_free to complete.
I don't know what I was thinking putting 'rcu' after a dynamically
sized array!  The array could still be in use when we call rcu_free()
(That is the point) so we mustn't corrupt it.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:43:53 +10:00
Namhyung Kim
a5bf4df0c8 md: use REQ_NOIDLE flag in md_super_write()
Queue idling is used for the anticipation of immediate
sequencial I/O's but md_super_write() is a kind of one-
shot operation, coupled with md_super_wait(), so the
idling in this case will be just a waste of time.

Specifying REQ_NOIDLE prevents it. Instead of adding
the flag to submit_bio() directly, use pre-defined
macro WRITE_FLUSH_FUA.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:43:34 +10:00
NeilBrown
aeb9b21184 md: ensure changes to 'write-mostly' are reflected in metadata.
The 'write-mostly' flag can be changed through sysfs.
With 0.90 metadata, those changes are reflected in the metadata.
For 1.x metadata, they aren't.

So fix super_1_sync to record 'write-mostly' status.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:43:08 +10:00
NeilBrown
5ef56c8fec md: report failure if a 'set faulty' request doesn't.
Sometimes a device will refuse to be set faulty.  e.g. RAID1 will
never let the last working device become faulty.

So check if "md_error()" did manage to set the faulty flag and fail
with EBUSY if it didn't.

Resolves-Debian-Bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=601198
Reported-by: Mike Hommey <mh+reportbug@glandium.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-08-25 14:42:51 +10:00
Mike Snitzer
ed8b752bcc dm table: set flush capability based on underlying devices
DM has always advertised both REQ_FLUSH and REQ_FUA flush capabilities
regardless of whether or not a given DM device's underlying devices
also advertised a need for them.

Block's flush-merge changes from 2.6.39 have proven to be more costly
for DM devices.  Performance regressions have been reported even when
DM's underlying devices do not advertise that they have a write cache.

Fix the performance regressions by configuring a DM device's flushing
capabilities based on those of the underlying devices' capabilities.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:08 +01:00
Milan Broz
772ae5f54d dm crypt: optionally support discard requests
Add optional parameter field to dmcrypt table and support
"allow_discards" option.

Discard requests bypass crypt queue processing. Bio is simple remapped
to underlying device.

Note that discard will be never enabled by default because of security
consequences.  It is up to the administrator to enable it for encrypted
devices.

(Note that userspace cryptsetup does not understand new optional
parameters yet.  Support for this will come later.  Until then, you
should use 'dmsetup' to enable and disable this.)

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:08 +01:00
Jonathan Brassow
327372797c dm raid: add md raid1 support
Support the MD RAID1 personality through dm-raid.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:07 +01:00
Jonathan Brassow
b12d437b73 dm raid: support metadata devices
Add the ability to parse and use metadata devices to dm-raid.  Although
not strictly required, without the metadata devices, many features of
RAID are unavailable.  They are used to store a superblock and bitmap.

The role, or position in the array, of each device must be recorded in
its superblock.  This is to help with fault handling, array reshaping,
and sanity checks.  RAID 4/5/6 devices must be loaded in a specific order:
in this way, the 'array_position' field helps validate the correctness
of the mapping when it is loaded.  It can be used during reshaping to
identify which devices are added/removed.  Fault handling is impossible
without this field.  For example, when a device fails it is recorded in
the superblock.  If this is a RAID1 device and the offending device is
removed from the array, there must be a way during subsequent array
assembly to determine that the failed device was the one removed.  This
is done by correlating the 'array_position' field and the bit-field
variable 'failed_devices'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:07 +01:00
Jonathan Brassow
46bed2b5c1 dm raid: add write_mostly parameter
Add the write_mostly parameter to RAID1 dm-raid tables.

This allows the user to set the WriteMostly flag on a RAID1 device that
should normally be avoided for read I/O.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:07 +01:00
Jonathan Brassow
c1084561bb dm raid: add region_size parameter
Allow the user to specify the region_size.

Ensures that the supplied value meets md's constraints, viz. the number of
regions does not exceed 2^21.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:07 +01:00
Mikulas Patocka
759dea204c dm ioctl: forbid multiple device specifiers
Exactly one of name, uuid or device must be specified when referencing
an existing device.  This removes the ambiguity (risking the wrong
device being updated) if two conflicting parameters were specified.
Previously one parameter got used and any others were ignored silently.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:06 +01:00
Mikulas Patocka
ba2e19b0f4 dm ioctl: introduce __get_dev_cell
Move logic to find device based on major/minor number to a separate
function __get_dev_cell (similar to __get_uuid_cell and __get_name_cell).
This makes the function __find_device_hash_cell more straightforward.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:06 +01:00
Mikulas Patocka
0ddf9644cc dm ioctl: fill in device parameters in more ioctls
Move parameter filling from find_device to __find_device_hash_cell.

This patch causes ioctls using __find_device_hash_cell
(DM_DEV_REMOVE_CMD, DM_DEV_SUSPEND_CMD - resume, DM_TABLE_CLEAR_CMD)
to return device parameters, bringing them into line with the other
ioctls.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:06 +01:00
Mike Snitzer
a3998799fb dm flakey: add corrupt_bio_byte feature
Add corrupt_bio_byte feature to simulate corruption by overwriting a byte at a
specified position with a specified value during intervals when the device is
"down".

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:06 +01:00
Mike Snitzer
b26f5e3d71 dm flakey: add drop_writes
Add 'drop_writes' option to drop writes silently while the
device is 'down'.  Reads are not touched.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:05 +01:00
Mike Snitzer
dfd068b01f dm flakey: support feature args
Add the ability to specify arbitrary feature flags when creating a
flakey target.  This code uses the same target argument helpers that
the multipath target does.

Also remove the superfluous 'dm-flakey' prefixes from the error messages,
as they already contain the prefix 'flakey'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:05 +01:00
Mike Snitzer
30e4171bfe dm flakey: use dm_target_offset and support discards
Use dm_target_offset() and support discards.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:05 +01:00
Mike Snitzer
498f0103ea dm table: share target argument parsing functions
Move multipath target argument parsing code into dm-table so other
targets can share it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:04 +01:00
Mikulas Patocka
a6e50b409d dm snapshot: skip reading origin when overwriting complete chunk
If we write a full chunk in the snapshot, skip reading the origin device
because the whole chunk will be overwritten anyway.

This patch changes the snapshot write logic when a full chunk is written.
In this case:
  1. allocate the exception
  2. dispatch the bio (but don't report the bio completion to device mapper)
  3. write the exception record
  4. report bio completed

Callbacks must be done through the kcopyd thread, because callbacks must not
race with each other.  So we create two new functions:

  dm_kcopyd_prepare_callback: allocate a job structure and prepare the callback.
  (This function must not be called from interrupt context.)

  dm_kcopyd_do_callback: submit callback.
  (This function may be called from interrupt context.)

Performance test (on snapshots with 4k chunk size):
  without the patch:
    non-direct-io sequential write (dd):    17.7MB/s
    direct-io sequential write (dd):        20.9MB/s
    non-direct-io random write (mkfs.ext2): 0.44s

  with the patch:
    non-direct-io sequential write (dd):    26.5MB/s
    direct-io sequential write (dd):        33.2MB/s
    non-direct-io random write (mkfs.ext2): 0.27s

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:04 +01:00
Mikulas Patocka
d5b9dd04bd dm: ignore merge_bvec for snapshots when safe
Add a new flag DMF_MERGE_IS_OPTIONAL to struct mapped_device to indicate
whether the device can accept bios larger than the size its merge
function returns.  When set, use this to send large bios to snapshots
which can split them if necessary.  Snapshot I/O may be significantly
fragmented and this approach seems to improve peformance.

Before the patch, dm_set_device_limits restricted bio size to page size
if the underlying device had a merge function and the target didn't
provide a merge function.  After the patch, dm_set_device_limits
restricts bio size to page size if the underlying device has a merge
function, doesn't have DMF_MERGE_IS_OPTIONAL flag and the target doesn't
provide a merge function.

The snapshot target can't provide a merge function because when the merge
function is called, it is impossible to determine where the bio will be
remapped.  Previously this led us to impose a 4k limit, which we can
now remove if the snapshot store is located on a device without a merge
function.  Together with another patch for optimizing full chunk writes,
it improves performance from 29MB/s to 40MB/s when writing to the
filesystem on snapshot store.

If the snapshot store is placed on a non-dm device with a merge function
(such as md-raid), device mapper still limits all bios to page size.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:04 +01:00
Mike Snitzer
0864901254 dm table: clean dm_get_device and move exports
There is no need for __table_get_device to be factored out.
Also move the exports to the end of their respective functions.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:04 +01:00
Alasdair G Kergon
3e8dbb7f39 dm raid: tidy includes
A dm target only needs to use include/linux dm headers.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:03 +01:00
Alasdair G Kergon
2ca4c92f58 dm ioctl: prevent empty message
Detect invalid empty messages in core dm instead of requiring every target to
check this.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:03 +01:00
Jonathan Brassow
13c87583ea dm raid: cleanup parameter handling
Re-order the parameters so they are handled consistently in the same order
where defined, parsed and output.

Only include rebuild parameters in the STATUSTYPE_TABLE output if they were
supplied in the original table line.

Correct the parameter count when outputting rebuild: there are two words,
not one.

Use case-independent checks for keywords (as in other device-mapper targets).

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:03 +01:00
Jonathan Brassow
a2d2b0345a dm snapshot: style cleanups
Coding style cleanups.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
2011-08-02 12:32:03 +01:00
Mikulas Patocka
aa3f0794d2 dm snapshot: remove unused definitions
Remove a couple of unused #defines.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:03 +01:00
Mikulas Patocka
5bf45a3dcd dm kcopyd: remove nr_pages field from job structure
The nr_pages field in struct kcopyd_job is only used temporarily in
run_pages_job() to count the number of required pages.
We can use a local variable instead.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:02 +01:00
Mikulas Patocka
4622afb3f5 dm kcopyd: remove offset field from job structure
The offset field in struct kcopyd_job is always zero so remove it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:02 +01:00
Joe Perches
e29e65aacb dm: use vzalloc
Use vzalloc() instead of vmalloc()+memset().

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:02 +01:00
Kirill A. Shutemov
6c9b27ab08 dm log: userspace use list_move
Replace list_del() followed by list_add() with list_move().

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:02 +01:00
Akinobu Mita
c8f543e078 dm log: clean up bit little endian bitops
Using __test_and_{set,clear}_bit_le() with ignoring its return value
can be replaced with __{set,clear}_bit_le().

This also removes unnecessary casts.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:01 +01:00
Mike Snitzer
936688d7eb dm table: fix discard support
Remove 'discards_supported' from the dm_table structure.  The same
information can be easily discovered from the table's target(s) in
dm_table_supports_discards().

Before this fix dm_table_supports_discards() would skip checking the
individual targets' 'discards_supported' flag if any one target in the
table didn't set num_discard_requests > 0.  Now the per-target
'discards_supported' flag is effective at insuring the final DM device
advertises discard support.  But, to be clear, targets that don't
support discards (!num_discard_requests) will not receive discard
requests.

Also DMWARN if a target sets 'discards_supported' override but forgets
to set 'num_discard_requests'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:01 +01:00
Alasdair G Kergon
283a8328ca dm: suppress endian warnings
Suppress sparse warnings about cpu_to_le32() by using __le32 types for
on-disk data etc.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:01 +01:00
Alasdair G Kergon
d15b774c29 dm: fix idr leak on module removal
Destroy _minor_idr when unloading the core dm module.  (Found by kmemleak.)

Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:01 +01:00
Mikulas Patocka
bb91bc7bac dm io: flush cpu cache with vmapped io
For normal kernel pages, CPU cache is synchronized by the dma layer.
However, this is not done for pages allocated with vmalloc. If we do I/O
to/from vmallocated pages, we must synchronize CPU cache explicitly.

Prior to doing I/O on vmallocated page we must call
flush_kernel_vmap_range to flush dirty cache on the virtual address.
After finished read we must call invalidate_kernel_vmap_range to
invalidate cache on the virtual address, so that accesses to the virtual
address return newly read data and not stale data from CPU cache.

This patch fixes metadata corruption on dm-snapshots on PA-RISC and
possibly other architectures with caches indexed by virtual address.

Cc: stable <stable@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:01 +01:00
Mike Snitzer
286f367dad dm mpath: fix potential NULL pointer in feature arg processing
Avoid dereferencing a NULL pointer if the number of feature arguments
supplied is fewer than indicated.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
2011-08-02 12:32:00 +01:00
Mikulas Patocka
762a80d9fc dm snapshot: flush disk cache when merging
This patch makes dm-snapshot flush disk cache when writing metadata for
merging snapshot.

Without cache flushing the disk may reorder metadata write and other
data writes and there is a possibility of data corruption in case of
power fault.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-08-02 12:32:00 +01:00
Linus Torvalds
6140333d36 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (75 commits)
  md/raid10: handle further errors during fix_read_error better.
  md/raid10: Handle read errors during recovery better.
  md/raid10: simplify read error handling during recovery.
  md/raid10: record bad blocks due to write errors during resync/recovery.
  md/raid10:  attempt to fix read errors during resync/check
  md/raid10:  Handle write errors by updating badblock log.
  md/raid10: clear bad-block record when write succeeds.
  md/raid10: avoid writing to known bad blocks on known bad drives.
  md/raid10 record bad blocks as needed during recovery.
  md/raid10: avoid reading known bad blocks during resync/recovery.
  md/raid10 - avoid reading from known bad blocks - part 3
  md/raid10: avoid reading from known bad blocks - part 2
  md/raid10: avoid reading from known bad blocks - part 1
  md/raid10: Split handle_read_error out from raid10d.
  md/raid10: simplify/reindent some loops.
  md/raid5: Clear bad blocks on successful write.
  md/raid5.  Don't write to known bad block on doubtful devices.
  md/raid5: write errors should be recorded as bad blocks if possible.
  md/raid5: use bad-block log to improve handling of uncorrectable read errors.
  md/raid5: avoid reading from known bad blocks.
  ...
2011-07-28 05:50:27 -07:00
NeilBrown
58c54fcca3 md/raid10: handle further errors during fix_read_error better.
If we find more read/write errors we should record a bad block before
failing the device.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:25 +10:00
NeilBrown
5e5702898e md/raid10: Handle read errors during recovery better.
Currently when we get a read error during recovery, we simply abort
the recovery.

Instead, repeat the read in page-sized blocks.
On successful reads, write to the target.
On read errors, record a bad block on the destination,
and only if that fails do we abort the recovery.

As we now retry reads we need to know where we read from.  This was in
bi_sector but that can be changed during a read attempt.
So store the correct from_addr and to_addr in the r10_bio for later
access.


Signed-off-by: NeilBrown<neilb@suse.de>
2011-07-28 11:39:25 +10:00
NeilBrown
e684e41db3 md/raid10: simplify read error handling during recovery.
If a read error is detected during recovery the code currently
fails the read device.
This isn't really necessary.  recovery_request_write will signal
a write error to end_sync_write and it will record a write
error on the destination device which will record a bad block
there or kick it from the array.

So just remove this call to do md_error.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:25 +10:00
NeilBrown
1a0b7cd826 md/raid10: record bad blocks due to write errors during resync/recovery.
If we get a write error during resync/recovery don't fail the device
but instead record a bad block.  If that fails we can then fail the
device.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:25 +10:00
NeilBrown
f84ee364dd md/raid10: attempt to fix read errors during resync/check
We already attempt to fix read errors found during normal IO
and a 'repair' process.
It is best to try to repair them at any time they are found,
so move a test so that during sync and check a read error will
be corrected by over-writing with good data.

If both (all) devices have known bad blocks in the sync section we
won't try to fix even though the bad blocks might not overlap.  That
should be considered later.

Also if we hit a read error during recovery we don't try to fix it.
It would only be possible to fix if there were at least three copies
of data, which is not very common with RAID10.  But it should still
be considered later.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:25 +10:00
NeilBrown
bd870a16c5 md/raid10: Handle write errors by updating badblock log.
When we get a write error (in the data area, not in metadata),
update the badblock log rather than failing the whole device.

As the write may well be many blocks, we trying writing each
block individually and only log the ones which fail.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00
NeilBrown
749c55e942 md/raid10: clear bad-block record when write succeeds.
If we succeed in writing to a block that was recorded as
being bad, we clear the bad-block record.

This requires some delayed handling as the bad-block-list update has
to happen in process-context.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00
NeilBrown
d4432c23be md/raid10: avoid writing to known bad blocks on known bad drives.
Writing to known bad blocks on drives that have seen a write error
is asking for trouble.  So try to avoid these blocks.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00
NeilBrown
e875ecea26 md/raid10 record bad blocks as needed during recovery.
When recovering one or more devices, if all the good devices have
bad blocks we should record a bad block on the device being rebuilt.

If this fails, we need to abort the recovery.

To ensure we don't think that we aborted later than we actually did,
we need to move the check for MD_RECOVERY_INTR earlier in md_do_sync,
in particular before mddev->curr_resync is updated.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00
NeilBrown
40c356ce5a md/raid10: avoid reading known bad blocks during resync/recovery.
During resync/recovery limit the size of the request to avoid
reading into a bad block that does not start at-or-before the current
read address.

Similarly if there is a bad block at this address, don't allow the
current request to extend beyond the end of that bad block.

Now that we don't ever read from known bad blocks, it is safe to allow
devices with those blocks into the array.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00
NeilBrown
8dbed5cebd md/raid10 - avoid reading from known bad blocks - part 3
When attempting to repair a read error, don't read from
devices with a known bad block.

As we are only reading PAGE_SIZE blocks, we don't try to
narrow down to smaller regions in the hope that only part of this
page is bad - it isn't worth the effort.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:24 +10:00
NeilBrown
7399c31bc9 md/raid10: avoid reading from known bad blocks - part 2
When redirecting a read error to a different device, we must
again avoid bad blocks and possibly split the request.

Spin_lock typo fixed thanks to Dan Carpenter <error27@gmail.com>

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:23 +10:00
NeilBrown
856e08e237 md/raid10: avoid reading from known bad blocks - part 1
This patch just covers the basic read path:
 1/ read_balance needs to check for badblocks, and return not only
    the chosen slot, but also how many good blocks are available
    there.
 2/ read submission must be ready to issue multiple reads to
    different devices as different bad blocks on different devices
    could mean that a single large read cannot be served by any one
    device, but can still be served by the array.
    This requires keeping count of the number of outstanding requests
    per bio.  This count is stored in 'bi_phys_segments'

On read error we currently just fail the request if another target
cannot handle the whole request.  Next patch refines that a bit.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:23 +10:00
NeilBrown
560f8e5532 md/raid10: Split handle_read_error out from raid10d.
raid10d() is too big and is about to get bigger, so split
handle_read_error() out as a separate function.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:23 +10:00
NeilBrown
1294b9c973 md/raid10: simplify/reindent some loops.
When a loop ends with a large if, it can be neater to change the
if to invert the condition and just 'continue'.
Then the body of the if can be indented to a lower level.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:23 +10:00
NeilBrown
b84db560ea md/raid5: Clear bad blocks on successful write.
On a successful write to a known bad block, flag the sh
so that raid5d can remove the known bad block from the list.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:23 +10:00
NeilBrown
73e92e51b7 md/raid5. Don't write to known bad block on doubtful devices.
If a device has seen write errors, don't write to any known
bad blocks on that device.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:22 +10:00
NeilBrown
bc2607f393 md/raid5: write errors should be recorded as bad blocks if possible.
When a write error is detected, don't mark the device as failed
immediately but rather record the fact for handle_stripe to deal with.

Handle_stripe then attempts to record a bad block.  Only if that fails
does the device get marked as faulty.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:22 +10:00
NeilBrown
7f0da59bdc md/raid5: use bad-block log to improve handling of uncorrectable read errors.
If we get an uncorrectable read error - record a bad block rather than
failing the device.
And if these errors (which may be due to known bad blocks) cause
recovery to be impossible, record a bad block on the recovering
devices, or abort the recovery.

As we might abort a recovery without failing a device we need to teach
RAID5 about recovery_disabled handling.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:22 +10:00
NeilBrown
31c176ecdf md/raid5: avoid reading from known bad blocks.
There are two times that we might read in raid5:
1/ when a read request fits within a chunk on a single
   working device.
   In this case, if there is any bad block in the range of
   the read, we simply fail the cache-bypass read and
   perform the read though the stripe cache.

2/ when reading into the stripe cache.  In this case we
   mark as failed any device which has a bad block in that
   strip (1 page wide).
   Note that we will both avoid reading and avoid writing.
   This is correct (as we will never read from the block, there
   is no point writing), but not optimal (as writing could 'fix'
   the error) - that will be addressed later.

If we have not seen any write errors on the device yet, we treat a bad
block like a recent read error.  This will encourage an attempt to fix
the read error which will either generate a write error, or will
ensure good data is stored there.  We don't yet forget the bad block
in that case.  That comes later.

Now that we honour bad blocks when reading we can allow devices with
bad blocks into the array.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:39:22 +10:00
NeilBrown
62096bce23 md/raid1: factor several functions out or raid1d()
raid1d is too big with several deep branches.
So separate them out into their own functions.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:38:13 +10:00
NeilBrown
3a9f28a511 md/raid1: improve handling of read failure during recovery.
If we cannot read a block from anywhere during recovery, there is
now a better approach than just giving up.
We can record a bad block on each device and keep going - being
careful not to clear the bad block when a write succeeds as it might -
it will be a write of incorrect data.

We have now reached the state where - for raid1 - we only call
md_error if md_set_badblocks has failed.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:33:42 +10:00
NeilBrown
d8f05d2995 md/raid1: record badblocks found during resync etc.
If we find a bad block while writing as part of resync/recovery we
need to report that back to raid1d which must record the bad block,
or fail the device.

Similarly when fixing a read error, a further error should just
record a bad block if possible rather than failing the device.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:33:00 +10:00
NeilBrown
cd5ff9a16f md/raid1: Handle write errors by updating badblock log.
When we get a write error (in the data area, not in metadata),
update the badblock log rather than failing the whole device.

As the write may well be many blocks, we trying writing each
block individually and only log the ones which fail.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:32:41 +10:00
NeilBrown
2ca68f5ed7 md/raid1: store behind-write pages in bi_vecs.
When performing write-behind we allocate pages to store the data
during write.
Previously we just keep a list of pages.  Now we keep a list of
bi_vec which includes offset and size.
This means that the r1bio has complete information to create a new
bio which will be needed for retrying after write errors.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:32:10 +10:00
NeilBrown
4367af5561 md/raid1: clear bad-block record when write succeeds.
If we succeed in writing to a block that was recorded as
being bad, we clear the bad-block record.

This requires some delayed handling as the bad-block-list update has
to happen in process-context.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:49 +10:00
NeilBrown
1f68f0c4b6 md/raid1: avoid writing to known-bad blocks on known-bad drives.
If we have seen any write error on a drive, then don't write to
any known-bad blocks on that drive.
If necessary, we divide the write request up into pieces just
like we do for reads, so each piece is either all written or
all not written to any given drive.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:48 +10:00
NeilBrown
de393cdea6 md: make it easier to wait for bad blocks to be acknowledged.
It is only safe to choose not to write to a bad block if that bad
block is safely recorded in metadata - i.e. if it has been
'acknowledged'.

If it hasn't we need to wait for the acknowledgement.

We support that using rdev->blocked wait and
md_wait_for_blocked_rdev by introducing a new device flag
'BlockedBadBlock'.

This flag is only advisory.
It is cleared whenever we acknowledge a bad block, so that a waiter
can re-check the particular bad blocks that it is interested it.

It should be set by a caller when they find they need to wait.
This (set after test) is inherently racy, but as
md_wait_for_blocked_rdev already has a timeout, losing the race will
have minimal impact.

When we clear "Blocked" was also clear "BlockedBadBlocks" incase it
was set incorrectly (see above race).

We also modify the way we manage 'Blocked' to fit better with the new
handling of 'BlockedBadBlocks' and to make it consistent between
externally managed and internally managed metadata.   This requires
that each raidXd loop checks if the metadata needs to be written and
triggers a write (md_check_recovery) if needed.  Otherwise a queued
write request might cause raidXd to wait for the metadata to write,
and only that thread can write it.

Before writing metadata, we set FaultRecorded for all devices that
are Faulty, then after writing the metadata we clear Blocked for any
device for which the Fault was certainly Recorded.

The 'faulty' device flag now appears in sysfs if the device is faulty
*or* it has unacknowledged bad blocks.  So user-space which does not
understand bad blocks can continue to function correctly.
User space which does, should not assume a device is faulty until it
sees the 'faulty' flag, and then sees the list of unacknowledged bad
blocks is empty.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:48 +10:00
NeilBrown
d7a9d443bc md: add 'write_error' flag to component devices.
If a device has ever seen a write error, we will want to handle
known-bad-blocks differently.
So create an appropriate state flag and export it via sysfs.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:48 +10:00
NeilBrown
06f603851f md/raid1: avoid reading known bad blocks during resync
When performing resync/etc, keep the size of the request
small enough that it doesn't overlap any known bad blocks.
Devices with badblocks at the start of the request are completely
excluded.
If there is nowhere to read from due to bad blocks, record
a bad block on each target device.

Now that we never read from known-bad-blocks we can allow devices with
known-bad-blocks into a RAID1.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:48 +10:00
NeilBrown
d2eb35acfd md/raid1: avoid reading from known bad blocks.
Now that we have a bad block list, we should not read from those
blocks.
There are several main parts to this:
  1/ read_balance needs to check for bad blocks, and return not only
     the chosen device, but also how many good blocks are available
     there.
  2/ fix_read_error needs to avoid trying to read from bad blocks.
  3/ read submission must be ready to issue multiple reads to
     different devices as different bad blocks on different devices
     could mean that a single large read cannot be served by any one
     device, but can still be served by the array.
     This requires keeping count of the number of outstanding requests
     per bio.  This count is stored in 'bi_phys_segments'
  4/ retrying a read needs to also be ready to submit a smaller read
     and queue another request for the rest.

This does not yet handle bad blocks when reading to perform resync,
recovery, or check.

'md_trim_bio' will also be used for RAID10, so put it in md.c and
export it.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:48 +10:00
NeilBrown
9f2f383078 md: Disable bad blocks and v0.90 metadata.
v0.90 metadata cannot record bad blocks, so when loading metadata
for such a device, set shift to -1.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:47 +10:00
NeilBrown
2699b67223 md: load/store badblock list from v1.x metadata
Space must have been allocated when array was created.
A feature flag is set when the badblock list is non-empty, to
ensure old kernels don't load and trust the whole device.

We only update the on-disk badblocklist when it has changed.
If the badblocklist (or other metadata) is stored on a bad block, we
don't cope very well.

If metadata has no room for bad block, flag bad-blocks as disabled,
and do the same for 0.90 metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 11:31:47 +10:00
NeilBrown
34b343cff4 md: don't allow arrays to contain devices with bad blocks.
As no personality understand bad block lists yet, we must
reject any device that is known to contain bad blocks.
As the personalities get taught, these tests can be removed.

This only applies to raid1/raid5/raid10.
For linear/raid0/multipath/faulty the whole concept of bad blocks
doesn't mean anything so there is no point adding the checks.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:47 +10:00
NeilBrown
16c791a5af md/bad-block-log: add sysfs interface for accessing bad-block-log.
This can show the log (providing it fits in one page) and
allows bad blocks to be 'acknowledged' meaning that they
have safely been recorded in metadata.

Clearing bad blocks is not allowed via sysfs (except for
code testing).  A bad block can only be cleared when
a write to the block succeeds.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:47 +10:00
NeilBrown
2230dfe4cc md: beginnings of bad block management.
This the first step in allowing md to track bad-blocks per-device so
that we can fail individual blocks rather than the whole device.

This patch just adds a data structure for recording bad blocks, with
routines to add, remove, search the list.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-28 11:31:46 +10:00
NeilBrown
a519b26dbe md: remove suspicious size_of()
When calling bioset_create we pass the size of the front_pad as
   sizeof(mddev)
which looks suspicious as mddev is a pointer and so it looks like a
common mistake where
   sizeof(*mddev)
was intended.
The size is actually correct as we want to store a pointer in the
front padding of the bios created by the bioset, so make the intent
more explicit by using
   sizeof(mddev_t *)

Reported-by: Zdenek Kabelac <zdenek.kabelac@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-28 07:56:24 +10:00
Jonathan Brassow
768e587e18 MD: generate an event when array sync is complete
This patch causes MD to generate an event (for device-mapper) when the
synchronization thread is reaped.  This is expected behavior for device-mapper.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:37 +10:00
Jonathan Brassow
3520fa4db7 MD bitmap: Revert DM dirty log hooks
Revert most of commit e384e58549
  md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.

MD should not need to use DM's dirty log - we decided to use md's
bitmaps instead.

Keeping the DIV_ROUND_UP clean-ups that were part of commit
e384e58549, however.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:37 +10:00
Jonathan Brassow
654e8b5abc MD: raid1 s/sysfs_notify_dirent/sysfs_notify_dirent_safe
If device-mapper creates a RAID1 array that includes devices to
be rebuilt, it will deref a NULL pointer when finished because
sysfs is not used by device-mapper instantiated RAID devices.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
NeilBrown
8cfa7b0f67 md/raid5: Avoid BUG caused by multiple failures.
While preparing to write a stripe we keep the parity block or blocks
locked (R5_LOCKED) - towards the end of schedule_reconstruction.

If the array is discovered to have failed before this write completes
we can leave those blocks LOCKED, and init_stripe will notice that a
free stripe still has a locked block and will complain.

So clear the R5_LOCKED flag in handle_failed_stripe, and demote the
'BUG' to a 'WARN_ON'.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim
cbea21703b md/raid10: move rdev->corrected_errors counting
Read errors are considered to corrected if write-back and re-read
cycle is finished without further problems. Thus moving the rdev->
corrected_errors counting after the re-reading looks more reasonable
IMHO.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim
ddd5115fe5 md/raid5: move rdev->corrected_errors counting
Read errors are considered to corrected if write-back and re-read
cycle is finished without further problems. Thus moving the rdev->
corrected_errors counting after the re-reading looks more reasonable
IMHO.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim
9d3d80113d md/raid1: move rdev->corrected_errors counting
Read errors are considered to corrected if write-back and re-read
cycle is finished without further problems. Thus moving the rdev->
corrected_errors counting after the re-reading looks more reasonable
IMHO. Also included a couple of whitespace fixes on sync_page_io().

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim
65a06f0674 md: get rid of unnecessary casts on page_address()
page_address() returns void pointer, so the casts can be removed.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
NeilBrown
700c721389 md/raid10: Improve decision on whether to fail a device with a read error.
Normally we would fail a device with a READ error.  However if doing
so causes the array to fail, it is better to leave the device
in place and just return the read error to the caller.

The current test for decide if the array will fail is overly
simplistic.
We have a function 'enough' which can tell if the array is failed or
not, so use it to guide the decision.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
NeilBrown
2bb77736ae md/raid10: Make use of new recovery_disabled handling
When we get a read error during recovery, RAID10 previously
arranged for the recovering device to appear to fail so that
the recovery stops and doesn't restart.  This is misleading and wrong.

Instead, make use of the new recovery_disabled handling and mark
the target device and having recovery disabled.

Add appropriate checks in add_disk and remove_disk so that devices
are removed and not re-added when recovery is disabled.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
NeilBrown
5389042ffa md: change managed of recovery_disabled.
If we hit a read error while recovering a mirror, we want to abort the
recovery without necessarily failing the disk - as having a disk this
a read error is better than not having an array at all.

Currently this is managed with a per-array flag "recovery_disabled"
and is only implemented for RAID1.  For RAID10 we will need finer
grained control as we might want to disable recovery for individual
devices separately.

So push more of the decision making into the personality.
'recovery_disabled' is now a 'cookie' which is copied when the
personality want to disable recovery and is changed when a device is
added to the array as this is used as a trigger to 'try recovery
again'.

This will allow RAID10 to get the control that it needs.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim
a478a069b6 md: remove ro check in md_check_recovery()
Commit c89a8eee61 ("Allow faulty devices to be removed from a
readonly array.") added some work on ro array in the function,
but it couldn't be done since we didn't allow the ro array to be
handled from the beginning. Fix it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Namhyung Kim
36fad858a7 md: introduce link/unlink_rdev() helpers
There are places where sysfs links to rdev are handled
in a same way. Add the helper functions to consolidate
them.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Christian Dietrich
8bda470e8e md/raid: use printk_ratelimited instead of printk_ratelimit
As per printk_ratelimit comment, it should not be used.

Signed-off-by: Christian Dietrich <christian.dietrich@informatik.uni-erlangen.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
Akinobu Mita
a0a02a7ad6 md: use proper little-endian bitops
Using __test_and_{set,clear}_bit_le() with ignoring its return value
can be replaced with __{set,clear}_bit_le().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: NeilBrown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-27 11:00:36 +10:00
NeilBrown
acfe726bdd md/raid5: finalise new merged handle_stripe.
handle_stripe5() and handle_stripe6() are now virtually identical.
So discard one and rename the other to 'analyse_stripe()'.

It always returns 0, so change it to 'void' and remove the 'done'
variable in handle_stripe().

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27 11:00:36 +10:00
NeilBrown
474af965fe md/raid5: move some more common code into handle_stripe
The RAID6 version of this code is usable for RAID5 providing:
  - we test "conf->max_degraded" rather than "2" as appropriate
  - we make sure s->failed_num[1] is meaningful (and not '-1')
    when s->failed > 1

The 'return 1' must become 'goto finish' in the new location.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27 11:00:36 +10:00
NeilBrown
84789554e9 md/raid5: move more common code into handle_stripe
Apart from 'prexor' which can only be set for RAID5, and
'qd_idx' which can only be meaningful for RAID6, these two
chunks of code are nearly the same.

So combine them into one adding a test to call either
handle_parity_checks5 or handle_parity_checks6 as appropriate.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27 11:00:36 +10:00
NeilBrown
c8ac1803ff md/raid5: unite handle_stripe_dirtying5 and handle_stripe_dirtying6
RAID6 is only allowed to choose 'reconstruct-write' while RAID5 is
also allow 'read-modify-write'
Apart from this difference, handle_stripe_dirtying[56] are nearly
identical.  So resolve these differences and create just one function.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27 11:00:36 +10:00
NeilBrown
93b3dbce64 md/raid5: unite fetch_block5 and fetch_block6
Provided that ->failed_num[1] is not a valid device number (which is
easily achieved) fetch_block6 provides all the functionality of
fetch_block5.

So remove the latter and rename the former to simply "fetch_block".

Then handle_stripe_fill5 and handle_stripe_fill6 become the same and
can similarly be united.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27 11:00:36 +10:00
NeilBrown
5d35e09cae md/raid5: rearrange a test in fetch_block6.
Next patch will unite fetch_block5 and fetch_block6.
First I want to make the differences a little more clear.

For RAID6 if we are writing at all and there is a failed device, then
we need to load or compute every block so we can do a
reconstruct-write.
This case isn't needed for RAID5 - we will do a read-modify-write in
that case.
So make that test a separate test in fetch_block6 rather than merged
with two other tests.

Make a similar change in fetch_block5 so the one bit that is not
needed for RAID6 is clearly separate.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27 11:00:36 +10:00
NeilBrown
c5a3100062 md/raid5: move more code into common handle_stripe
The difference between the RAID5 and RAID6 code here is easily
resolved using conf->max_degraded.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27 11:00:36 +10:00
NeilBrown
3687c06188 md/raid5: Move code for finishing a reconstruction into handle_stripe.
Prior to commit ab69ae12ce the code in handle_stripe5 and
handle_stripe6 to "Finish reconstruct operations initiated by the
expansion process" was identical.
That commit added an identical stanza of code to each function, but in
different places.  That was careless.

The raid5 code was correct, so move that out into handle_stripe and
remove raid6 version.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27 11:00:36 +10:00
NeilBrown
86c374ba9f md/raid5: Remove stripe_head_state arg from handle_stripe_expansion.
This arg is only used to differentiate between RAID5 and RAID6 but
that is not needed.  For RAID5, raid5_compute_sector will set qd_idx
to "~0" so j with certainly not equals qd_idx, so there is no need
for a guard on that condition.

So remove the guard and remove the arg from the declaration and
callers of handle_stripe_expansion.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-27 11:00:36 +10:00
Arun Sharma
60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
NeilBrown
cc94015a9e md/raid5: move stripe_head_state and more code into handle_stripe.
By defining the 'stripe_head_state' in 'handle_stripe', we can move
some common code out of handle_stripe[56]() and into handle_stripe.

The means that all accesses for stripe_head_state in handle_stripe[56]
need to be 's->' instead of 's.', but the compiler should inline
those functions and just use a direct stack reference, and future
patches while hoist most of this code up into handle_stripe()
so we will revert to "s.".

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26 11:35:35 +10:00
NeilBrown
c5709ef6a0 md/raid5: add some more fields to stripe_head_state
Adding these three fields will allow more common code to be moved
to handle_stripe()

struct field rearrangement by Namhyung Kim.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26 11:35:20 +10:00
NeilBrown
f2b3b44dee md/raid5: unify stripe_head_state and r6_state
'struct stripe_head_state' stores state about the 'current' stripe
that is passed around while handling the stripe.
For RAID6 there is an extension structure: r6_state, which is also
passed around.
There is no value in keeping these separate, so move the fields from
the latter into the former.

This means that all code now needs to treat s->failed_num as an small
array, but this is a small cost.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26 11:35:19 +10:00
NeilBrown
82e5a1718b md/raid5: move common code into handle_stripe
There is common code at the start of handle_stripe5 and
handle_stripe6.  Move it into handle_stripe.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26 11:35:15 +10:00
NeilBrown
c4c1663be4 md/raid5: replace sh->lock with an 'active' flag.
sh->lock is now mainly used to ensure that two threads aren't running
in the locked part of handle_stripe[56] at the same time.

That can more neatly be achieved with an 'active' flag which we set
while running handle_stripe.  If we find the flag is set, we simply
requeue the stripe for later by setting STRIPE_HANDLE.

For safety we take ->device_lock while examining the state of the
stripe and creating a summary in 'stripe_head_state / r6_state'.
This possibly isn't needed but as shared fields like ->toread,
->towrite are checked it is safer for now at least.

We leave the label after the old 'unlock' called "unlock" because it
will disappear in a few patches, so renaming seems pointless.

This leaves the stripe 'locked' for longer as we clear STRIPE_ACTIVE
later, but that is not a problem.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26 11:34:20 +10:00
NeilBrown
cbe47ec559 md/raid5: Protect some more code with ->device_lock.
Other places that change or follow dev->towrite and dev->written take
the device_lock as well as the sh->lock.
So it should really be held in these places too.
Also, doing so will allow sh->lock to be discarded.

with merged fixes by: Namhyung Kim <namhyung@gmail.com>


Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26 11:20:35 +10:00
NeilBrown
83206d66b6 md/raid5: Remove use of sh->lock in sync_request
This is the start of a series of patches to remove sh->lock.

sync_request takes sh->lock before setting STRIPE_SYNCING to ensure
there is no race with testing it in handle_stripe[56].

Instead, use a new flag STRIPE_SYNC_REQUESTED and test it early
in handle_stripe[56] (after getting the same lock) and perform the
same set/clear operations if it was set.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
2011-07-26 11:19:49 +10:00
Linus Torvalds
bbd9d6f7fb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (107 commits)
  vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp
  isofs: Remove global fs lock
  jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
  fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
  mm/truncate.c: fix build for CONFIG_BLOCK not enabled
  fs:update the NOTE of the file_operations structure
  Remove dead code in dget_parent()
  AFS: Fix silly characters in a comment
  switch d_add_ci() to d_splice_alias() in "found negative" case as well
  simplify gfs2_lookup()
  jfs_lookup(): don't bother with . or ..
  get rid of useless dget_parent() in btrfs rename() and link()
  get rid of useless dget_parent() in fs/btrfs/ioctl.c
  fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
  drivers: fix up various ->llseek() implementations
  fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
  Ext4: handle SEEK_HOLE/SEEK_DATA generically
  Btrfs: implement our own ->llseek
  fs: add SEEK_HOLE and SEEK_DATA flags
  reiserfs: make reiserfs default to barrier=flush
  ...

Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new
shrinker callout for the inode cache, that clashed with the xfs code to
start the periodic workers later.
2011-07-22 19:02:39 -07:00
Kay Sievers
f15146380d fs: seq_file - add event counter to simplify poll() support
Moving the event counter into the dynamically allocated 'struc seq_file'
allows poll() support without the need to allocate its own tracking
structure.

All current users are switched over to use the new counter.

Requested-by: Andrew Morton akpm@linux-foundation.org
Acked-by: NeilBrown <neilb@suse.de>
Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:50 -04:00
Lai Jiangshan
b119cbab3a md,rcu: Convert call_rcu(free_conf) to kfree_rcu()
The rcu callback free_conf() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(free_conf).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NeilBrown <neilb@suse.de>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-07-20 11:05:29 -07:00
Namhyung Kim
ffd96e35c1 md/raid5: get rid of duplicated call to bio_data_dir()
In raid5::make_request(), once bio_data_dir(@bi) is detected
it never (and couldn't) be changed. Use the result always.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-18 17:38:51 +10:00
Namhyung Kim
6ce328462c md/raid5: use kmem_cache_zalloc()
Replace kmem_cache_alloc + memset(,0,) to kmem_cache_zalloc.
I think it's not harmful since @conf->slab_cache already knows
actual size of struct stripe_head.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-18 17:38:50 +10:00
Namhyung Kim
c65060ad42 md/raid10: share pages between read and write bio's during recovery
When performing a recovery, only first 2 slots in r10_bio are in use,
for read and write respectively. However all of pages in the write bio
are never used and just replaced to read bio's when the read completes.

Get rid of those unused pages and share read pages properly.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-18 17:38:49 +10:00
Namhyung Kim
778ca01852 md/raid10: factor out common bio handling code
When normal-write and sync-read/write bio completes, we should
find out the disk number the bio belongs to. Factor those common
code out to a separate function.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-18 17:38:47 +10:00
Namhyung Kim
2c4193df37 md/raid10: get rid of duplicated conditional expression
Variable 'first' is initialized to zero and updated to @rdev->raid_disk
only if it is greater than 0. Thus condition '>= first' always implies
'>= 0' so the latter is not needed.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-07-18 17:38:43 +10:00
NeilBrown
4274215d24 md: avoid endless recovery loop when waiting for fail device to complete.
If a device fails in a way that causes pending request to take a while
to complete, md will not be able to immediately remove it from the
array in remove_and_add_spares.
It will then incorrectly look like a spare device and md will try to
recover it even though it is failed.
This leads to a recovery process starting and instantly aborting over
and over again.

We should check if the device is faulty before considering it to be a
spare.  This will avoid trying to start a recovery that cannot
proceed.

This bug was introduced in 2.6.26 so that patch is suitable for any
kernel since then.

Cc: stable@kernel.org
Reported-by: Jim Paradis <james.paradis@stratus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-28 16:59:42 +10:00
Namhyung Kim
fcde90759a md/raid5: remove unusual use of bio_iovec_idx()
In the bio_for_each_segment loop, bvl always points current
bio_vec, so the same as bio_iovec_idx(, i). Let's get rid of
it.

Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-14 14:23:57 +10:00
Namhyung Kim
b062962edb md/raid5: fix FUA request handling in ops_run_io()
Commit e9c7469bb4 ("md: implment REQ_FLUSH/FUA support")
introduced R5_WantFUA flag and set rw to WRITE_FUA in that case.
However remaining code still checks whether rw is exactly same
as WRITE or not, so FUAed-write ends up with being treated as
READ. Fix it.

This bug has been present since 2.6.37 and the fix is suitable for any
-stable kernel since then.  It is not clear why this has not caused
more problems.

Cc: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-14 14:20:19 +10:00
Namhyung Kim
9b2dc8b665 md/raid5: fix raid5_set_bi_hw_segments
The @bio->bi_phys_segments consists of active stripes count in the
lower 16 bits and processed stripes count in the upper 16 bits. So
logical-OR operator should be bitwise one.

This bug has been present since 2.6.27 and the fix is suitable for any
-stable kernel since then.  Fortunately the bad code is only used on
error paths and is relatively unlikely to be hit.

Cc: stable@kernel.org
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-14 14:09:41 +10:00
Namhyung Kim
97b3d4aacf md/bitmap: remove unused fields from struct bitmap
Get rid of ->syncchunk and ->counter_bits since they're never used.

Also discard COUNTER_BYTE_RATIO which is unused.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:43:01 +10:00
Namhyung Kim
27d5ea04d0 md/bitmap: use proper accessor macro
Use COUNTER()/NEEDED() macro instead of open-coding them.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:57 +10:00
Namhyung Kim
01393f3d58 md: check ->hot_remove_disk when removing disk
Check pers->hot_remove_disk instead of pers->hot_add_disk in slot_store()
during disk removal. The linear personality only has ->hot_add_disk and
no ->hot_remove_disk, so that removing disk in the array resulted to
following kernel bug:

$ sudo mdadm --create /dev/md0 --level=linear --raid-devices=4 /dev/loop[0-3]
$ echo none | sudo tee /sys/block/md0/md/dev-loop2/slot
 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [<          (null)>]           (null)
 PGD c9f5d067 PUD 8575a067 PMD 0
 Oops: 0010 [#1] SMP
 CPU 2
 Modules linked in: linear loop bridge stp llc kvm_intel kvm asus_atk0110 sr_mod cdrom sg

 Pid: 10450, comm: tee Not tainted 3.0.0-rc1-leonard+ #173 System manufacturer System Product Name/P5G41TD-M PRO
 RIP: 0010:[<0000000000000000>]  [<          (null)>]           (null)
 RSP: 0018:ffff880085757df0  EFLAGS: 00010282
 RAX: ffffffffa00168e0 RBX: ffff8800d1431800 RCX: 000000000000006e
 RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff88008543c000
 RBP: ffff880085757e48 R08: 0000000000000002 R09: 000000000000000a
 R10: 0000000000000000 R11: ffff88008543c2e0 R12: 00000000ffffffff
 R13: ffff8800b4641000 R14: 0000000000000005 R15: 0000000000000000
 FS:  00007fe8c9e05700(0000) GS:ffff88011fa00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: 0000000000000000 CR3: 00000000b4502000 CR4: 00000000000406e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Process tee (pid: 10450, threadinfo ffff880085756000, task ffff8800c9f08000)
 Stack:
  ffffffff8138496a ffff8800b4641000 ffff88008543c268 0000000000000000
  ffff8800b4641000 ffff88008543c000 ffff8800d1431868 ffffffff81a78a90
  ffff8800b4641000 ffff88008543c000 ffff8800d1431800 ffff880085757e98
 Call Trace:
  [<ffffffff8138496a>] ? slot_store+0xaa/0x265
  [<ffffffff81384bae>] rdev_attr_store+0x89/0xa8
  [<ffffffff8115a96a>] sysfs_write_file+0x108/0x144
  [<ffffffff81106b87>] vfs_write+0xb1/0x10d
  [<ffffffff8106e6c0>] ? trace_hardirqs_on_caller+0x111/0x135
  [<ffffffff81106cac>] sys_write+0x4d/0x77
  [<ffffffff814fe702>] system_call_fastpath+0x16/0x1b
 Code:  Bad RIP value.
 RIP  [<          (null)>]           (null)
  RSP <ffff880085757df0>
 CR2: 0000000000000000
 ---[ end trace ba5fc64319a826fb ]---

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:54 +10:00
马建朋
9864c0053d md: Using poll /proc/mdstat can monitor the events of adding a spare disks
Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:48 +10:00
Jonathan Brassow
d744540cd3 MD: use is_power_of_2 macro
Make use of is_power_of_2 macro.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:36 +10:00
Jonathan Brassow
d6b212f4b1 MD: raid5 do not set fullsync
Add check to determine if a device needs full resync or if partial resync will do

RAID 5 was assuming that if a device was not In_sync, it must undergo a full
resync.  We add a check to see if 'saved_raid_disk' is the same as 'raid_disk'.
If it is, we can safely skip the full resync and rely on the bitmap for
partial recovery instead.  This is the legitimate purpose of 'saved_raid_disk',
from md.h:
int saved_raid_disk;            /* role that device used to have in the
                                 * array and could again if we did a partial
                                 * resync from the bitmap
                                 */

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:42:29 +10:00
Jonathan Brassow
9c81075f43 MD: support initial bitmap creation in-kernel
Add bitmap support to the device-mapper specific metadata area.

This patch allows the creation of the bitmap metadata area upon
initial array creation via device-mapper.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-09 11:41:36 +10:00
Jonathan Brassow
076f968b37 MD: add sync_super to mddev_t struct
Add the 'sync_super' function pointer to MD array structure (struct mddev_s)

If device-mapper (dm-raid.c) is to define its own on-disk superblock and be
able to load it, there must still be a way for MD to initiate superblock
updates.  The simplest way to make this happen is to provide a pointer in
the MD array structure that can be set by device-mapper (or other module)
with a function to do this.  If the function has been set, it will be used;
otherwise, the method with be looked up via 'super_types' as usual.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:11:31 +10:00
Jonathan Brassow
1ed7242e59 MD: raid1 changes to allow use by device mapper
MD RAID1: Changes to allow RAID1 to be used by device-mapper (dm-raid.c)

Added the necessary congestion function and conditionalize calls requiring an
array 'queue' or 'gendisk'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:11:31 +10:00
Jonathan Brassow
0fd018af37 MD: move thread wakeups into resume
Move personality and sync/recovery thread starting outside md_run.

Moving the wakeup's of the personality and sync/recovery threads out of
md_run and into do_md_run and mddev_resume solves two issues:
1) It allows bitmap_load to be called before the sync_thread is run and
2) when MD personalities are used by device-mapper (dm-raid.c), the start-up
of the array is better alligned with device-mapper primatives
(CTR/resume/suspend/DTR).  I/O - in this case, recovery operations - should
not happen until after a resume has taken place.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:11:31 +10:00
Jonathan Brassow
ac42450c7c MD: possible typo
Make message a bit clearer by s/blocks/k/

I chose 'k' vs 'kiB' or 'kB' because it is what is used earlier in the
message.  'k' may be a bit ambigous, but I think it's better than "blocks"
which normally means 512, but means 1024 in MD.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:11:31 +10:00
Jonathan Brassow
68866e425b MD: no sync IO while suspended
Disallow resync I/O while the RAID array is suspended.

Recovery, resync, and metadata I/O should not be allowed while a device is
suspended.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:10:08 +10:00
Jonathan Brassow
629acb6aba MD: no integrity register if no gendisk
Don't attempt md_integrity_register if there is no gendisk struct available.

When MD arrays are built via device-mapper, the gendisk structure is not
available via mddev.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-06-08 15:10:08 +10:00
Mikulas Patocka
fa34ce7307 dm kcopyd: return client directly and not through a pointer
Return client directly from dm_kcopyd_client_create, not through a
parameter, making it consistent with dm_io_client_create.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 13:03:13 +01:00
Mikulas Patocka
5f43ba2950 dm kcopyd: reserve fewer pages
Reserve just the minimum of pages needed to process one job.

Because we allocate pages from page allocator, we don't need to reserve
a large number of pages.  The maximum job size is SUB_JOB_SIZE and we
calculate the number of reserved pages based on this.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 13:03:11 +01:00
Mikulas Patocka
bda8efec5c dm io: use fixed initial mempool size
Replace the arbitrary calculation of an initial io struct mempool size
with a constant.

The code calculated the number of reserved structures based on the request
size and used a "magic" multiplication constant of 4.  This patch changes
it to reserve a fixed number - itself still chosen quite arbitrarily.
Further testing might show if there is a better number to choose.

Note that if there is no memory pressure, we can still allocate an
arbitrary number of "struct io" structures.  One structure is enough to
process the whole request.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 13:03:09 +01:00
Mikulas Patocka
d04714580f dm kcopyd: alloc pages from the main page allocator
This patch changes dm-kcopyd so that it allocates pages from the main
page allocator with __GFP_NOWARN | __GFP_NORETRY flags (so that it can
fail in case of memory pressure). If the allocation fails, dm-kcopyd
allocates pages from its own reserve.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 13:03:07 +01:00
Mikulas Patocka
f99b55eec7 dm kcopyd: add gfp parm to alloc_pl
Introduce a parameter for gfp flags to alloc_pl() for use in following
patches.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 13:03:04 +01:00
Mikulas Patocka
4cc1b4cffd dm kcopyd: remove superfluous page allocation spinlock
Remove the spinlock protecting the pages allocation.  The spinlock is only
taken on initialization or from single-threaded workqueue.  Therefore, the
spinlock is useless.

The spinlock is taken in kcopyd_get_pages and kcopyd_put_pages.

kcopyd_get_pages is only called from run_pages_job, which is only
called from process_jobs called from do_work.

kcopyd_put_pages is called from client_alloc_pages (which is initialization
function) or from run_complete_job. run_complete_job is only called from
process_jobs called from do_work.

Another spinlock, kc->job_lock is taken each time someone pushes or pops
some work for the worker thread.  Once we take kc->job_lock, we
guarantee that any written memory is visible to the other CPUs.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 13:03:02 +01:00
Mikulas Patocka
c6ea41fbbe dm kcopyd: preallocate sub jobs to avoid deadlock
There's a possible theoretical deadlock in dm-kcopyd because multiple
allocations from the same mempool are required to finish a request.
Avoid this by preallocating sub jobs.

There is a mempool of 512 entries. Each request requires up to 9
entries from the mempool. If we have at least 57 concurrent requests
running, the mempool may overflow and mempool allocations may start
blocking until another entry is freed to the mempool. Because the same
thread is used to free entries to the mempool and allocate entries from
the mempool, this may result in a deadlock.

This patch changes it so that one mempool entry contains all 9 "struct
kcopyd_job" required to fulfill the whole request. The allocation is
done only once in dm_kcopyd_copy and no further mempool allocations are
done during request processing.

If dm_kcopyd_copy is not run in the completion thread, this
implementation is deadlock-free.

MIN_JOBS needs reducing accordingly and we've chosen to reduce it
further to 8.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 13:03:00 +01:00
Mikulas Patocka
a705a34a56 dm kcopyd: avoid pointless job splitting
Don't split SUB_JOB_SIZE jobs

If the job size equals SUB_JOB_SIZE, there is no point in splitting it.
Splitting it just unnecessarily wastes time, because the split job size
is SUB_JOB_SIZE too.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 13:02:58 +01:00
Martin K. Petersen
6f13f6fba7 dm mpath: do not fail paths after integrity errors
Integrity errors need to be passed to the owner of the integrity
metadata for processing. Consequently EILSEQ should be passed up the
stack.

Cc: stable@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 13:02:55 +01:00
Milan Broz
f4808ca99a dm table: reject devices without request fns
This patch adds a check that a block device has a request function
defined before it is used.  Otherwise, misconfiguration can cause an oops.

Because we are allowing devices with zero size e.g. an offline multipath
device as in commit 2cd54d9bed
("dm: allow offline devices") there needs to be an additional check
to ensure devices are initialised.  Some block devices, like a loop
device without a backing file, exist but have no request function.

Reproducer is trivial: dm-mirror on unbound loop device
(no backing file on loop devices)

dmsetup create x --table "0 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0"

and mirror resync will immediatelly cause OOps.

BUG: unable to handle kernel NULL pointer dereference at   (null)
 ? generic_make_request+0x2bd/0x590
 ? kmem_cache_alloc+0xad/0x190
 submit_bio+0x53/0xe0
 ? bio_add_page+0x3b/0x50
 dispatch_io+0x1ca/0x210 [dm_mod]
 ? read_callback+0x0/0xd0 [dm_mirror]
 dm_io+0xbb/0x290 [dm_mod]
 do_mirror+0x1e0/0x748 [dm_mirror]

Signed-off-by: Milan Broz <mbroz@redhat.com>
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 13:02:52 +01:00
Mike Snitzer
4c25932701 dm table: allow targets to support discards internally
Permit a target to support discards regardless of whether or not all its
underlying devices do.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-05-29 12:52:55 +01:00
Linus Torvalds
57d19e80f4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  b43: fix comment typo reqest -> request
  Haavard Skinnemoen has left Atmel
  cris: typo in mach-fs Makefile
  Kconfig: fix copy/paste-ism for dell-wmi-aio driver
  doc: timers-howto: fix a typo ("unsgined")
  perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c
  md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course').
  treewide: fix a few typos in comments
  regulator: change debug statement be consistent with the style of the rest
  Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations"
  audit: acquire creds selectively to reduce atomic op overhead
  rtlwifi: don't touch with treewide double semicolon removal
  treewide: cleanup continuations and remove logging message whitespace
  ath9k_hw: don't touch with treewide double semicolon removal
  include/linux/leds-regulator.h: fix syntax in example code
  tty: fix typo in descripton of tty_termios_encode_baud_rate
  xtensa: remove obsolete BKL kernel option from defconfig
  m68k: fix comment typo 'occcured'
  arch:Kconfig.locks Remove unused config option.
  treewide: remove extra semicolons
  ...
2011-05-23 09:12:26 -07:00
NeilBrown
b098636cf0 md: allow resync_start to be set while an array is active.
The sysfs attribute 'resync_start' (known internally as recovery_cp),
records where a resync is up to.  A value of 0 means the array is
not known to be in-sync at all.  A value of MaxSector means the array
is believed to be fully in-sync.

When the size of member devices of an array (RAID1,RAID4/5/6) is
increased, the array can be increased to match.  This process sets
resync_start to the old end-of-device offset so that the new part of
the array gets resynced.

However with RAID1 (and RAID6) a resync is not technically necessary
and may be undesirable.  So it would be good if the implied resync
after the array is resized could be avoided.

So: change 'resync_start' so the value can be changed while the array
is active, and as a precaution only allow it to be changed while
resync/recovery is 'frozen'.  Changing it once resync has started is
not going to be useful anyway.

This allows the array to be resized without a resync by:
  write 'frozen' to 'sync_action'
  write new size to 'component_size' (this will set resync_start)
  write 'none' to 'resync_start'
  write 'idle' to 'sync_action'.

Also slightly improve some tests on recovery_cp when resizing
raid1/raid5.  Now that an arbitrary value could be set we should be
more careful in our tests.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 15:52:21 +10:00
NeilBrown
ab9d47e990 md/raid10: reformat some loops with less indenting.
When a loop ends with an 'if' with a large body, it is neater
to make the if 'continue' on the inverse condition, and then
the body is indented less.

Apply this pattern 3 times, and wrap some other long lines.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:54:41 +10:00
NeilBrown
f17ed07c85 md/raid10: remove unused variable.
This variable 'disk' is never used - how odd.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:54:32 +10:00
NeilBrown
a8830bcaf3 md/raid10: make more use of 'slot' in raid10d.
Now that we have a 'slot' variable, make better use of it to simplify
some code a little.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:54:19 +10:00
NeilBrown
7c4e06ff2b md/raid10: some tidying up in fix_read_error
Currently the rdev on which a read error happened could be removed
before we perform the fix_error handling.  This requires extra tests
for NULL.

So delay the rdev_dec_pending call until after the call to
fix_read_error so that we can be sure that the rdev still exists.

This allows an 'if' clause to be removed so the body gets re-indented
back one level.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:53:17 +10:00
NeilBrown
af6d7b760c md/raid1: improve handling of pages allocated for write-behind.
The current handling and freeing of these pages is a bit fragile.
We only keep the list of allocated pages in each bio, so we need to
still have a valid bio when freeing the pages, which is a bit clumsy.

So simply store the allocated page list in the r1_bio so it can easily
be found and freed when we are finished with the r1_bio.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:51:19 +10:00
NeilBrown
7ca78d57d1 md/raid1: try fix_sync_read_error before process_checks.
If we get a read error during resync/recovery we current repeat with
single-page reads to find out just where the error is, and possibly
read each page from a different device.

With check/repair we don't currently do that, we just fail.
However it is possible that while all devices fail on the large 64K
read, we might be able to satisfy each 4K from one device or another.

So call fix_sync_read_error before process_checks to maximise the
chance of finding good data and writing it out to the devices with
read errors.

For this to work, we need to set the 'uptodate' flags properly after
fix_sync_read_error has succeeded.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:50:37 +10:00
NeilBrown
78d7f5f726 md/raid1: tidy up new functions: process_checks and fix_sync_read_error.
These changes are mostly cosmetic:

1/ change mddev->raid_disks to conf->raid_disks because the later is
   technically safer, though in current practice it doesn't matter in
   this particular context.
2/ Rearrange two for / if loops to have an early 'continue' so the
   body of the 'if' doesn't need to be indented so much.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:48:56 +10:00
NeilBrown
a68e587035 md/raid1: split out two sub-functions from sync_request_write
sync_request_write is too big and too deep.
So split out two self-contains bits of functionality into separate
function.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:40:44 +10:00
NeilBrown
6f8d0c77ce md: make error_handler functions more uniform and correct.
- there is no need to test_bit Faulty, as that was already done in
  md_error which is the only caller of these functions.
- MD_CHANGE_DEVS should be set *after* faulty is set to ensure
  metadata is updated correctly.
- spinlock should be held while updating ->degraded.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:38:44 +10:00
NeilBrown
92f861a72a md/multipath: discard ->working_disks in favour of ->degraded
conf->working_disks duplicates information already available
in mddev->degraded.
So remove working_disks.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:38:02 +10:00
NeilBrown
76073054c9 md/raid1: clean up read_balance.
read_balance has two loops which both look for a 'best'
device based on slightly different criteria.
This is clumsy and makes is hard to add extra criteria.

So replace it all with a single loop that combines everything.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:34:56 +10:00
NeilBrown
56d9912106 md: simplify raid10 read_balance
raid10 read balance has two different loop for looking through
possible devices to chose the best.
Collapse those into one loop and generally make the code more
readable.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:27:03 +10:00
NeilBrown
8258c53208 md/bitmap: fix saving of events_cleared and other state.
If a bitmap is found to be 'stale' the events_cleared value
is set to match 'events'.
However if the array is degraded this does not get stored on disk.
This can subsequently lead to incorrect behaviour.

So change bitmap_update_sb to always update events_cleared in the
superblock from the known events_cleared.
For neatness also set ->state from ->flags.
This requires updating ->state whenever we update ->flags, which makes
sense anyway.

This is suitable for any active -stable release.

cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:26:30 +10:00
NeilBrown
bedd86b777 md: reject a re-add request that cannot be honoured.
The 'add_new_disk' ioctl can be used to add a device either as a
spare, or as an active disk that just needs to be resynced based on
write-intent-bitmap information (re-add)

Currently if a re-add is requested but fails we add as a spare
instead.  This makes it impossible for user-space to check for
failure.

So change to require that a re-add attempt will either succeed or
completely fail.  User-space can then decide what to do next.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-05-11 14:26:20 +10:00
NeilBrown
b0140891a8 md: Fix race when creating a new md device.
There is a race when creating an md device by opening /dev/mdXX.

If two processes do this at much the same time they will follow the
call path
  __blkdev_get -> get_gendisk -> kobj_lookup

The first will call
  -> md_probe -> md_alloc -> add_disk -> blk_register_region

and the race happens when the second gets to kobj_lookup after
add_disk has called blk_register_region but before it returns to
md_alloc.

In the case the second will not call md_probe (as the probe is already
done) but will get a handle on the gendisk, return to __blkdev_get
which will then call md_open (via the ->open) pointer.

As mddev->gendisk hasn't been set yet, md_open will think something is
wrong an return with ERESTARTSYS.

This can loop endlessly while the first thread makes no progress
through add_disk.  Nothing is blocking it, but due to scheduler
behaviour it doesn't get a turn.
So this is essentially a live-lock.

We fix this by simply moving the assignment to mddev->gendisk before
the call the add_disk() so md_open doesn't get confused.
Also move blk_queue_flush earlier because add_disk should be as late
as possible.

To make sure that md_open doesn't complete until md_alloc has done all
that is needed, we take mddev->open_mutex during the last part of
md_alloc.  md_open will wait for this.

This can cause a lock-up on boot so Cc:ing for stable.
For 2.6.36 and earlier a different patch will be needed as the
'blk_queue_flush' call isn't there.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Tested-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Cc: stable@kernel.org
2011-05-11 14:26:17 +10:00
Jesper Juhl
aeb878b096 md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course').
There's a small typo in a comment in drivers/md/raid5.c - 'Of course' is
misspelled as 'Ofcourse'. This patch fixes the spelling error.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-05-10 10:18:36 +02:00
Randy Dunlap
d76c8420c3 raid5: fix build error, sector_t usage
Change <sectors> from unsigned long long to sector_t.
This matches its source field.

  ERROR: "__udivdi3" [drivers/md/raid456.ko] undefined!

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-21 10:00:00 -07:00
Krzysztof Wojcik
fee68723cf md: Cleanup after raid45->raid0 takeover
Problem:
After raid4->raid0 takeover operation, another takeover operation
(e.g raid0->raid10) results "kernel oops".
Root cause:
Variables 'degraded' in mddev structure is not cleared
on raid45->raid0 takeover.

This patch reset this variable.

Signed-off-by: Krzysztof Wojcik <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-20 15:39:53 +10:00
NeilBrown
3b71bd9337 md: Fix dev_sectors on takeover from raid0 to raid4/5
A raid0 array doesn't set 'dev_sectors' as each device might
contribute a different number of sectors.
So when converting to a RAID4 or RAID5 we need to set dev_sectors
as they need the number.
We have already verified that in fact all devices do contribute
the same number of sectors, so use that number.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-20 15:38:18 +10:00
NeilBrown
2b7da309ff md/raid5: remove setting of ->queue_lock
We previously needed to set ->queue_lock to match the raid5
device_lock so we could safely use queue_flag_* operations (e.g. for
plugging). which test the ->queue_lock is in fact locked.

However that need has completely gone away and is unlikely to come
back to remove this now-pointless setting.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-20 15:38:07 +10:00
NeilBrown
c3b328ac84 md: fix up raid1/raid10 unplugging.
We just need to make sure that an unplug event wakes up the md
thread, which is exactly what mddev_check_plugged does.

Also remove some plug-related code that is no longer needed.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18 18:25:43 +10:00
NeilBrown
7c13edc875 md: incorporate new plugging into raid5.
In raid5 plugging is used for 2 things:
 1/ collecting writes that require a bitmap update
 2/ collecting writes in the hope that we can create full
    stripes - or at least more-full.

We now release these different sets of stripes when plug_cnt
is zero.

Also in make_request, we call mddev_check_plug to hopefully increase
plug_cnt, and wake up the thread at the end if plugging wasn't
achieved for some reason.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18 18:25:43 +10:00
NeilBrown
97658cdd3a md: provide generic support for handling unplug callbacks.
When an md device adds a request to a queue, it can call
mddev_check_plugged.
If this succeeds then we know that the md thread will be woken up
shortly, and ->plug_cnt will be non-zero until then, so some
processing can be delayed.

If it fails, then no unplug callback is expected and the make_request
function needs to do whatever is required to make the request happen.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18 18:25:42 +10:00
NeilBrown
482c083492 md - remove old plugging code.
md has some plugging infrastructure for RAID5 to use because the
normal plugging infrastructure required a 'request_queue', and when
called from dm, RAID5 doesn't have one of those available.

This relied on the ->unplug_fn callback which doesn't exist any more.

So remove all of that code, both in md and raid5.  Subsequent patches
with restore the plugging functionality.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18 18:25:42 +10:00
NeilBrown
af1db72d8b md/dm - remove remains of plug_fn callback.
Now that unplugging is done differently, the unplug_fn callback is
never called, so it can be completely discarded.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18 18:25:41 +10:00
NeilBrown
e1dfa0a297 md: use new plugging interface for RAID IO.
md/raid submits a lot of IO from the various raid threads.
So adding start/finish plug calls to those so that some
plugging happens.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-04-18 18:25:41 +10:00
Linus Torvalds
42933bac11 Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6
* 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6:
  Fix common misspellings
2011-04-07 11:14:49 -07:00
Mike Snitzer
a63a5cf84d dm: improve block integrity support
The current block integrity (DIF/DIX) support in DM is verifying that
all devices' integrity profiles match during DM device resume (which
is past the point of no return).  To some degree that is unavoidable
(stacked DM devices force this late checking).  But for most DM
devices (which aren't stacking on other DM devices) the ideal time to
verify all integrity profiles match is during table load.

Introduce the notion of an "initialized" integrity profile: a profile
that was blk_integrity_register()'d with a non-NULL 'blk_integrity'
template.  Add blk_integrity_is_initialized() to allow checking if a
profile was initialized.

Update DM integrity support to:
- check all devices with _initialized_ integrity profiles match
  during table load; uninitialized profiles (e.g. for underlying DM
  device(s) of a stacked DM device) are ignored.
- disallow a table load that would result in an integrity profile that
  conflicts with a DM device's existing (in-use) integrity profile
- avoid clearing an existing integrity profile
- validate all integrity profiles match during resume; but if they
  don't all we can do is report the mismatch (during resume we're past
  the point of no return)

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-04-05 23:52:43 +02:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Martin K. Petersen
89078d572e md: Fix integrity registration error when no devices are capable
We incorrectly returned -EINVAL when none of the devices in the array
had an integrity profile.  This in turn prevented mdadm from starting
the metadevice.  Fix this so we only return errors on mismatched
profiles and memory allocation failures.

Reported-by: Giacomo Catenazzi <cate@cateee.net>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-28 17:53:29 -07:00
Linus Torvalds
44bbd7ac26 Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm stripe: implement merge method
  dm mpath: allow table load with no priority groups
  dm mpath: fail message ioctl if specified path is not valid
  dm ioctl: add flag to wipe buffers for secure data
  dm ioctl: prepare for crypt key wiping
  dm crypt: wipe keys string immediately after key is set
  dm: add flakey target
  dm: fix opening log and cow devices for read only tables
2011-03-25 20:51:44 -07:00
Linus Torvalds
6c51038900 Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
  Documentation/iostats.txt: bit-size reference etc.
  cfq-iosched: removing unnecessary think time checking
  cfq-iosched: Don't clear queue stats when preempt.
  blk-throttle: Reset group slice when limits are changed
  blk-cgroup: Only give unaccounted_time under debug
  cfq-iosched: Don't set active queue in preempt
  block: fix non-atomic access to genhd inflight structures
  block: attempt to merge with existing requests on plug flush
  block: NULL dereference on error path in __blkdev_get()
  cfq-iosched: Don't update group weights when on service tree
  fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
  block: Require subsystems to explicitly allocate bio_set integrity mempool
  jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  fs: make fsync_buffers_list() plug
  mm: make generic_writepages() use plugging
  blk-cgroup: Add unaccounted time to timeslice_used.
  block: fixup plugging stubs for !CONFIG_BLOCK
  block: remove obsolete comments for blkdev_issue_zeroout.
  blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
  ...

Fix up conflicts in fs/{aio.c,super.c}
2011-03-24 10:16:26 -07:00
Mustafa Mesanovic
2991520200 dm stripe: implement merge method
Implement a merge function in the striped target.

When the striped target's underlying devices provide a merge_bvec_fn
(like all DM devices do via dm_merge_bvec) it is important to call down
to them when building a biovec that doesn't span a stripe boundary.

Without the merge method, a striped DM device stacked on DM devices
causes bios with a single page to be submitted which results
in unnecessary overhead that hurts performance.

This change really helps filesystems (e.g. XFS and now ext4) which take
care to assemble larger bios.  By implementing stripe_merge(), DM and the
stripe target no longer undermine the filesystem's work by only allowing
a single page per bio.  Buffered IO sees the biggest improvement
(particularly uncached reads, buffered writes to a lesser degree).  This
is especially so for more capable "enterprise" storage LUNs.

The performance improvement has been measured to be ~12-35% -- when a
reasonable chunk_size is used (e.g. 64K) in conjunction with a stripe
count that is a power of 2.

In contrast, the performance penalty is ~5-7% for the pathological worst
case stripe configuration (small chunk_size with a stripe count that is
not a power of 2).  The reason for this is that stripe_map_sector() is
now called once for every call to dm_merge_bvec().  stripe_map_sector()
will use slower division if stripe count isn't a power of 2.

Signed-off-by: Mustafa Mesanovic <mume@linux.vnet.ibm.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-03-24 13:54:35 +00:00
Mike Snitzer
a490a07a67 dm mpath: allow table load with no priority groups
This patch adjusts the multipath target to allow a table with both 0
priority groups and 0 for the initial priority group number.

If any mpath device is held open when all paths in the last priority
group have failed, userspace multipathd will attempt to reload the
associated DM table to reflect the fact that the device no longer has
any priority groups.  But the reload attempt always failed because the
multipath target did not allow 0 priority groups.

All multipath target messages related to priority group (enable_group,
disable_group, switch_group) will handle a priority group of 0 (will
cause error).

When reloading a multipath table with 0 priority groups, userspace
multipathd must be updated to specify an initial priority group number
of 0 (rather than 1).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Babu Moger <babu.moger@lsi.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-03-24 13:54:33 +00:00
Mike Snitzer
19040c0bc8 dm mpath: fail message ioctl if specified path is not valid
Fail the reinstate_path and fail_path message ioctl if the specified
path is not valid.

The message ioctl would succeed for the 'reinistate_path' and
'fail_path' messages even if action was not taken because the
specified device was not a valid path of the multipath device.

Before, when /dev/vdb is not a path of mpathb:
$ dmsetup message mpathb 0 reinstate_path /dev/vdb
$ echo $?
0

After:
$ dmsetup message mpathb 0 reinstate_path /dev/vdb
device-mapper: message ioctl failed: Invalid argument
Command failed
$ echo $?
1

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-03-24 13:54:31 +00:00
Milan Broz
f868120549 dm ioctl: add flag to wipe buffers for secure data
Add DM_SECURE_DATA_FLAG which userspace can use to ensure
that all buffers allocated for dm-ioctl are wiped
immediately after use.

The user buffer is wiped as well (we do not want to keep
and return sensitive data back to userspace if the flag is set).

Wiping is useful for cryptsetup to ensure that the key
is present in memory only in defined places and only
for the time needed.

(For crypt, key can be present in table during load or table
status, wait and message commands).

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-03-24 13:54:30 +00:00
Milan Broz
6bb43b5d1f dm ioctl: prepare for crypt key wiping
Prepare code for implementing buffer wipe flag.
No functional change in this patch.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-03-24 13:54:28 +00:00
Milan Broz
de8be5ac70 dm crypt: wipe keys string immediately after key is set
Always wipe the original copy of the key after processing it
in crypt_set_key().

Signed-off-by: Milan Broz <mbroz@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-03-24 13:54:27 +00:00
Josef Bacik
3407ef5262 dm: add flakey target
This target is the same as the linear target except that it returns I/O
errors periodically.  It's been found useful in simulating failing
devices for testing purposes.

I needed a dm target to do some failure testing on btrfs's raid code, and
Mike pointed me at this.

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-03-24 13:54:24 +00:00
Milan Broz
024d37e95e dm: fix opening log and cow devices for read only tables
If a table is read-only, also open any log and cow devices it uses read-only.

Previously, even read-only devices were opened read-write internally.
After patch 75f1dc0d07
  block: check bdev_read_only() from blkdev_get()
was applied, loading such tables began to fail.  The patch
was reverted by e51900f7d3
  block: revert block_dev read-only check
but this patch fixes this part of the code to work with the original patch.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-03-24 13:52:14 +00:00
Akinobu Mita
bb5cda3d70 dm: use little-endian bitops
As a preparation for removing ext2 non-atomic bit operations from
asm/bitops.h.  This converts ext2 non-atomic bit operations to
little-endian bit operations.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:46:20 -07:00
Akinobu Mita
6b33aff368 md: use little-endian bitops
As a preparation for removing ext2 non-atomic bit operations from
asm/bitops.h.  This converts ext2 non-atomic bit operations to
little-endian bit operations.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:46:20 -07:00
Shaohua Li
1e9bb8808a block: fix non-atomic access to genhd inflight structures
After the stack plugging introduction, these are called lockless.
Ensure that the counters are updated atomically.

Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-22 08:35:35 +01:00
Linus Torvalds
c55d267de2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (170 commits)
  [SCSI] scsi_dh_rdac: Add MD36xxf into device list
  [SCSI] scsi_debug: add consecutive medium errors
  [SCSI] libsas: fix ata list corruption issue
  [SCSI] hpsa: export resettable host attribute
  [SCSI] hpsa: move device attributes to avoid forward declarations
  [SCSI] scsi_debug: Logical Block Provisioning (SBC3r26)
  [SCSI] sd: Logical Block Provisioning update
  [SCSI] Include protection operation in SCSI command trace
  [SCSI] hpsa: fix incorrect PCI IDs and add two new ones (2nd try)
  [SCSI] target: Fix volume size misreporting for volumes > 2TB
  [SCSI] bnx2fc: Broadcom FCoE offload driver
  [SCSI] fcoe: fix broken fcoe interface reset
  [SCSI] fcoe: precedence bug in fcoe_filter_frames()
  [SCSI] libfcoe: Remove stale fcoe-netdev entries
  [SCSI] libfcoe: Move FCOE_MTU definition from fcoe.h to libfcoe.h
  [SCSI] libfc: introduce __fc_fill_fc_hdr that accepts fc_hdr as an argument
  [SCSI] fcoe, libfc: initialize EM anchors list and then update npiv EMs
  [SCSI] Revert "[SCSI] libfc: fix exchange being deleted when the abort itself is timed out"
  [SCSI] libfc: Fixing a memory leak when destroying an interface
  [SCSI] megaraid_sas: Version and Changelog update
  ...

Fix up trivial conflicts due to whitespace differences in
drivers/scsi/libsas/{sas_ata.c,sas_scsi_host.c}
2011-03-17 17:54:40 -07:00
Martin K. Petersen
a91a2785b2 block: Require subsystems to explicitly allocate bio_set integrity mempool
MD and DM create a new bio_set for every metadevice. Each bio_set has an
integrity mempool attached regardless of whether the metadevice is
capable of passing integrity metadata. This is a waste of memory.

Instead we defer the allocation decision to MD and DM since we know at
metadevice creation time whether integrity passthrough is needed or not.

Automatic integrity mempool allocation can then be removed from
bioset_create() and we make an explicit integrity allocation for the
fs_bio_set.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
Acked-by: Mike Snitzer <snizer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-17 11:11:05 +01:00
Linus Torvalds
7a6362800c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1480 commits)
  bonding: enable netpoll without checking link status
  xfrm: Refcount destination entry on xfrm_lookup
  net: introduce rx_handler results and logic around that
  bonding: get rid of IFF_SLAVE_INACTIVE netdev->priv_flag
  bonding: wrap slave state work
  net: get rid of multiple bond-related netdevice->priv_flags
  bonding: register slave pointer for rx_handler
  be2net: Bump up the version number
  be2net: Copyright notice change. Update to Emulex instead of ServerEngines
  e1000e: fix kconfig for crc32 dependency
  netfilter ebtables: fix xt_AUDIT to work with ebtables
  xen network backend driver
  bonding: Improve syslog message at device creation time
  bonding: Call netif_carrier_off after register_netdevice
  bonding: Incorrect TX queue offset
  net_sched: fix ip_tos2prio
  xfrm: fix __xfrm_route_forward()
  be2net: Fix UDP packet detected status in RX compl
  Phonet: fix aligned-mode pipe socket buffer header reserve
  netxen: support for GbE port settings
  ...

Fix up conflicts in drivers/staging/brcm80211/brcmsmac/wl_mac80211.c
with the staging updates.
2011-03-16 16:29:25 -07:00
Linus Torvalds
bd2895eead Merge branch 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix build failure introduced by s/freezeable/freezable/
  workqueue: add system_freezeable_wq
  rds/ib: use system_wq instead of rds_ib_fmr_wq
  net/9p: replace p9_poll_task with a work
  net/9p: use system_wq instead of p9_mux_wq
  xfs: convert to alloc_workqueue()
  reiserfs: make commit_wq use the default concurrency level
  ocfs2: use system_wq instead of ocfs2_quota_wq
  ext4: convert to alloc_workqueue()
  scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path
  scsi/be2iscsi,qla2xxx: convert to alloc_workqueue()
  misc/iwmc3200top: use system_wq instead of dedicated workqueues
  i2o: use alloc_workqueue() instead of create_workqueue()
  acpi: kacpi*_wq don't need WQ_MEM_RECLAIM
  fs/aio: aio_wq isn't used in memory reclaim path
  input/tps6507x-ts: use system_wq instead of dedicated workqueue
  cpufreq: use system_wq instead of dedicated workqueues
  wireless/ipw2x00: use system_wq instead of dedicated workqueues
  arm/omap: use system_wq in mailbox
  workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
2011-03-16 08:20:19 -07:00
Jens Axboe
4c63f5646e Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/core
Conflicts:
	block/blk-core.c
	block/blk-flush.c
	drivers/md/raid1.c
	drivers/md/raid10.c
	drivers/md/raid5.c
	fs/nilfs2/btnode.c
	fs/nilfs2/mdt.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:58:35 +01:00
Jens Axboe
721a9602e6 block: kill off REQ_UNPLUG
With the plugging now being explicitly controlled by the
submitter, callers need not pass down unplugging hints
to the block layer. If they want to unplug, it's because they
manually plugged on their own - in which case, they should just
unplug at will.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:27 +01:00
Jens Axboe
7eaceaccab block: remove per-queue plugging
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:07 +01:00
David S. Miller
0a0e9ae1bd Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/bnx2x/bnx2x.h
2011-03-03 21:27:42 -08:00
Patrick McHardy
01a16b21d6 netlink: kill eff_cap from struct netlink_skb_parms
Netlink message processing in the kernel is synchronous these days,
capabilities can be checked directly in security_netlink_recv() from
the current process.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Reviewed-by: James Morris <jmorris@namei.org>
[chrisw: update to include pohmelfs and uvesafb]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-03 13:32:07 -08:00
NeilBrown
f0b4f7e2f2 md: Fix - again - partition detection when array becomes active
Revert
    b821eaa572
and
    f3b99be19d

When I wrote the first of these I had a wrong idea about the
lifetime of 'struct block_device'.  It can disappear at any time that
the block device is not open if it falls out of the inode cache.

So relying on the 'size' recorded with it to detect when the
device size has changed and so we need to revalidate, is wrong.

Rather, we really do need the 'changed' attribute stored directly in
the mddev and set/tested as appropriate.

Without this patch, a sequence of:
   mknod / open / close / unlink

(which can cause a block_device to be created and then destroyed)
will result in a rescan of the partition table and consequence removal
and addition of partitions.
Several of these in a row can get udev racing to create and unlink and
other code can get confused.

With the patch, the rescan is only performed when needed and so there
are no races.

This is suitable for any stable kernel from 2.6.35.

Reported-by: "Wojcik, Krzysztof" <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2011-02-24 17:26:41 +11:00
Tejun Heo
43d133c18b Merge branch 'master' into for-2.6.39 2011-02-21 09:43:56 +01:00
NeilBrown
da9cf5050a md: avoid spinlock problem in blk_throtl_exit
blk_throtl_exit assumes that ->queue_lock still exists,
so make sure that it does.
To do this, we stop redirecting ->queue_lock to conf->device_lock
and leave it pointing where it is initialised - __queue_lock.

As the blk_plug functions check the ->queue_lock is held, we now
take that spin_lock explicitly around the plug functions.  We don't
need the locking, just the warning removal.

This is needed for any kernel with the blk_throtl code, which is
which is 2.6.37 and later.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-21 18:25:57 +11:00
NeilBrown
8f5f02c460 md: correctly handle probe of an 'mdp' device.
'mdp' devices are md devices with preallocated device numbers
for partitions. As such it is possible to mknod and open a partition
before opening the whole device.

this causes  md_probe() to be called with a device number of a
partition, which in-turn calls mddev_find with such a number.

However mddev_find expects the number of a 'whole device' and
does the wrong thing with partition numbers.

So add code to mddev_find to remove the 'partition' part of
a device number and just work with the 'whole device'.

This patch addresses https://bugzilla.kernel.org/show_bug.cgi?id=28652

Reported-by: hkmaly@bigfoot.com
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: <stable@kernel.org>
2011-02-16 13:58:51 +11:00
NeilBrown
cbe6ef1d26 md: don't set_capacity before array is active.
If the desired size of an array is set (via sysfs) before the array is
active (which is the normal sequence), we currrently call set_capacity
immediately.
This means that a subsequent 'open' (as can be caused by some
udev-triggers program) will notice the new size and try to probe for
partitions.  However as the array isn't quite ready yet the read will
fail.  Then when the array is read, as the size doesn't change again
we don't try to re-probe.

So when setting array size via sysfs, only call set_capacity if the
array is already active.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-16 13:58:38 +11:00
Krzysztof Wojcik
f7bee80945 md: Fix raid1->raid0 takeover
Takeover raid1->raid0 not succeded. Kernel message is shown:
"md/raid0:md126: too few disks (1 of 2) - aborting!"

Problem was that we weren't updating ->raid_disks for that
takeover, unlike all the others.

Signed-off-by: Krzysztof Wojcik <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-14 10:01:41 +11:00
Hannes Reinecke
751b2a7d62 [SCSI] dm mpath: propagate target errors immediately
DM now has more information about the nature of the underlying storage
failure.  Path failure is avoided if a request failed due to a target
error.  Instead the target error is immediately passed up the stack.

Discard requests that fail due to non-target errors may now be retried.

Errors restricted to the path will be retried or returned if no
paths are available, irregarding the no_path_retry setting.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-02-12 10:33:29 -06:00
Krzysztof Wojcik
02214dc546 FIX: md: process hangs at wait_barrier after 0->10 takeover
Following symptoms were observed:
1. After raid0->raid10 takeover operation we have array with 2
missing disks.
When we add disk for rebuild, recovery process starts as expected
but it does not finish- it stops at about 90%, md126_resync process
hangs in "D" state.
2. Similar behavior is when we have mounted raid0 array and we
execute takeover to raid10. After this when we try to unmount array-
it causes process umount hangs in "D"

In scenarios above processes hang at the same function- wait_barrier
in raid10.c.
Process waits in macro "wait_event_lock_irq" until the
"!conf->barrier" condition will be true.
In scenarios above it never happens.

Reason was that at the end of level_store, after calling pers->run,
we call mddev_resume. This calls pers->quiesce(mddev, 0) with
RAID10, that calls lower_barrier.
However raise_barrier hadn't been called on that 'conf' yet,
so conf->barrier becomes negative, which is bad.

This patch introduces setting conf->barrier=1 after takeover
operation. It prevents to become barrier negative after call
lower_barrier().

Signed-off-by: Krzysztof Wojcik <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-08 11:49:02 +11:00
Chris Mason
e91ece5590 md_make_request: don't touch the bio after calling make_request
md_make_request was calling bio_sectors() for part_stat_add
after it was calling the make_request function.  This is
bad because the make_request function can free the bio and
because the bi_size field can change around.

The fix here was suggested by Jens Axboe.  It saves the
sector count before the make_request call.  I hit this
with CONFIG_DEBUG_PAGEALLOC turned on while trying to break
his pretty fusionio card.

Cc: <stable@kernel.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-08 09:53:28 +11:00
NeilBrown
c6751b2bde md: Don't allow slot_store while resync/recovery is happening.
Activating a spare in an array while resync/recovery is already
happening can lead the that spare being marked in-sync when it isn't
really.
So don't allow the 'slot' to be set (this activating the device)
while resync/recovery is happening.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-02-02 11:57:13 +11:00
NeilBrown
7281f8129c md: don't clear curr_resync_completed at end of resync.
There is no need to set this to zero at this point.  It will be
set to zero by remove_and_add_spares or at the start of
md_do_sync at the latest.
And setting it to zero before MD_RECOVERY_RUNNING is cleared can
make a 'zero' appear briefly in the 'sync_completed' sysfs attribute
just as resync is finishing.

So simply remove this setting to zero.


Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 14:30:27 +11:00
NeilBrown
a8c42c7f47 md: Don't use remove_and_add_spares to remove failed devices from a read-only array
remove_and_add_spares is called in two places where the needs really
are very different.
remove_and_add_spares should not be called on an array which is about
to be reshaped as some extra devices might have been manually added
and that would remove them.  However if the array is 'read-auto',
that will currently happen, which is bad.

So in the 'ro != 0' case don't call remove_and_add_spares but simply
remove the failed devices as the comment suggests is needed.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 13:47:13 +11:00
Krzysztof Wojcik
fc3a08b85b Add raid1->raid0 takeover support
This patch introduces raid 1 to raid0 takeover operation
in kernel space.

Signed-off-by: Krzysztof Wojcik <krzysztof.wojcik@intel.com>
Signed-off-by: Neil Brown <neilb@nbeee.brown>
2011-01-31 13:47:13 +11:00
NeilBrown
f21e9ff7f7 md: Remove the AllReserved flag for component devices.
This flag is not needed and is used badly.

Devices that are included in a native-metadata array are reserved
exclusively for that array - and currently have AllReserved set.
They all are bd_claimed for the rdev and so cannot be shared.

Devices that are included in external-metadata arrays can be shared
among multiple arrays - providing there is no overlap.
These are bd_claimed for md in general - not for a particular rdev.

When changing the amount of a device that is used in an array we need
to check for overlap.  This currently includes a check on AllReserved
So even without overlap, sharing with an AllReserved device is not
allowed.
However the bd_claim usage already precludes sharing with these
devices, so the test on AllReserved is not needed.  And in fact it is
wrong.

As this is the only use of AllReserved, simply remove all usage and
definition of AllReserved.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 12:10:09 +11:00
NeilBrown
50da084096 md: don't abort checking spares as soon as one cannot be added.
As spares can be added manually before a reshape starts, we need to
find them all to mark some of them as in_sync.

Previously we would abort looking for spares when we found an
unallocated spare what could not be added to the array (implying there
was no room for new spares).  However already-added spares could be
later in the list, so we need to keep searching.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 11:57:43 +11:00
NeilBrown
469518a345 md: fix the test for finding spares in raid5_start_reshape.
As spares can be added to the array before the reshape is started,
we need to find and count them when checking there are enough.
The array could have been degraded, so we need to check all devices,
no just those out side of the range of devices in the array before
the reshape.

So instead of checking the index, check the In_sync flag as that
reliably tells if the device is a spare or this purpose.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 11:57:43 +11:00
NeilBrown
87a8dec91e md: simplify some 'if' conditionals in raid5_start_reshape.
There are two consecutive 'if' statements.

 if (mddev->delta_disks >= 0)
      ....
 if (mddev->delta_disks > 0)

The code in the second is equally valid if delta_disks == 0, and these
two statements are the only place that 'added_devices' is used.

So make them a single if statement, make added_devices a local
variable, and re-indent it all.

No functional change.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 11:57:43 +11:00
NeilBrown
de171cb9a5 md: revert change to raid_disks on failure.
If we try to update_raid_disks and it fails, we should put
'delta_disks' back to zero.  This is important because some code,
such as slot_store, assumes that delta_disks has been validated.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-31 11:57:42 +11:00
Tejun Heo
ada609ee2a workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
WQ_RESCUER is now an internal flag and should only be used in the
workqueue implementation proper.  Use WQ_MEM_RECLAIM instead.

This doesn't introduce any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: dm-devel@redhat.com
Cc: Neil Brown <neilb@suse.de>
2011-01-25 14:35:54 +01:00
Tejun Heo
49731baa41 block: restore multiple bd_link_disk_holder() support
Commit e09b457b (block: simplify holder symlink handling) incorrectly
assumed that there is only one link at maximum.  dm may use multiple
links and expects block layer to track reference count for each link,
which is different from and unrelated to the exclusive device holder
identified by @holder when the device is opened.

Remove the single holder assumption and automatic removal of the link
and revive the per-link reference count tracking.  The code
essentially behaves the same as before commit e09b457b sans the
unnecessary kobject reference count dancing.

While at it, note that this facility should not be used by anyone else
than the current ones.  Sysfs symlinks shouldn't be abused like this
and the whole thing doesn't belong in the block layer at all.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Milan Broz <mbroz@redhat.com>
Cc: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-01-14 18:44:22 +01:00
Linus Torvalds
f6bcfd94c0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (32 commits)
  dm: raid456 basic support
  dm: per target unplug callback support
  dm: introduce target callbacks and congestion callback
  dm mpath: delay activate_path retry on SCSI_DH_RETRY
  dm: remove superfluous irq disablement in dm_request_fn
  dm log: use PTR_ERR value instead of ENOMEM
  dm snapshot: avoid storing private suspended state
  dm snapshot: persistent make metadata_wq multithreaded
  dm: use non reentrant workqueues if equivalent
  dm: convert workqueues to alloc_ordered
  dm stripe: switch from local workqueue to system_wq
  dm: dont use flush_scheduled_work
  dm snapshot: remove unused dm_snapshot queued_bios_work
  dm ioctl: suppress needless warning messages
  dm crypt: add loop aes iv generator
  dm crypt: add multi key capability
  dm crypt: add post iv call to iv generator
  dm crypt: use io thread for reads only if mempool exhausted
  dm crypt: scale to multiple cpus
  dm crypt: simplify compatible table output
  ...
2011-01-13 17:30:47 -08:00
Linus Torvalds
509e4aef44 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  md: Fix removal of extra drives when converting RAID6 to RAID5
  md: range check slot number when manually adding a spare.
  md/raid5: handle manually-added spares in start_reshape.
  md: fix sync_completed reporting for very large drives (>2TB)
  md: allow suspend_lo and suspend_hi to decrease as well as increase.
  md: Don't let implementation detail of curr_resync leak out through sysfs.
  md: separate meta and data devs
  md-new-param-to_sync_page_io
  md-new-param-to-calc_dev_sboffset
  md: Be more careful about clearing flags bit in ->recovery
  md: md_stop_writes requires mddev_lock.
  md/raid5: use sysfs_notify_dirent_safe to avoid NULL pointer
  md: Ensure no IO request to get md device before it is properly initialised.
  md: Fix single printks with multiple KERN_<level>s
  md: fix regression resulting in delays in clearing bits in a bitmap
  md: fix regression with re-adding devices to arrays with no metadata
2011-01-13 17:30:20 -08:00
NeilBrown
bf2cb0dab8 md: Fix removal of extra drives when converting RAID6 to RAID5
When a RAID6 is converted to a RAID5, the extra drive should
be discarded.  However it isn't due to a typo in a comparison.

This bug was introduced in commit e93f68a1fc in 2.6.35-rc4
and is suitable for any -stable since than.

As the extra drive is not removed, the 'degraded' counter is wrong and
so the RAID5 will not respond correctly to a subsequent failure.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
NeilBrown
ba1b41b6b4 md: range check slot number when manually adding a spare.
When adding a spare to an active array, we should check the slot
number, but allow it to be larger than raid_disks if a reshape
is being prepared.

Apply the same test when adding a device to an
array-under-construction.  It already had most of the test in place,
but not quite all.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
NeilBrown
1a940fcee3 md/raid5: handle manually-added spares in start_reshape.
It is possible to manually add spares to specific slots before
starting a reshape.
raid5_start_reshape should recognised this possibility and include
it in the accounting.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Rémi Rérolle
13ae864bc8 md: fix sync_completed reporting for very large drives (>2TB)
The values exported in the sync_completed file are unsigned long, which
overflows with very large drives, resulting in wrong values reported.

Since sync_completed uses sectors as unit, we'll start getting wrong
values with components larger than 2TB.

This patch simply replaces the use of unsigned long by unsigned long long.

Signed-off-by: Rémi Rérolle <rrerolle@lacie.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
NeilBrown
23ddff3792 md: allow suspend_lo and suspend_hi to decrease as well as increase.
The sysfs attributes 'suspend_lo' and 'suspend_hi' describe a region
to which read/writes are suspended so that the under lying data can be
manipulated without user-space noticing.
Currently the window they describe can only move forwards along the
device.  However this is an unnecessary restriction which will cause
problems with planned developments.
So relax this restriction and allow these endpoints to move
arbitrarily.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
NeilBrown
75d3da43cb md: Don't let implementation detail of curr_resync leak out through sysfs.
mddev->curr_resync has artificial values of '1' and '2' which are used
by the code which ensures only one resync is happening at a time on
any given device.

These values are internal and should never be exposed to user-space
(except when translated appropriately as in the 'pending' status in
/proc/mdstat).

Unfortunately they are as ->curr_resync is assigned to
->curr_resync_completed and that value is directly visible through
sysfs.

So change the assignments to ->curr_resync_completed to get the same
valued from elsewhere in a form that doesn't have the magic '1' or '2'
values.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Jonathan Brassow
a6ff7e089c md: separate meta and data devs
Allow the metadata to be on a separate device from the
data.

This doesn't mean the data and metadata will by on separate
physical devices - it simply gives device-mapper and userspace
tools more flexibility.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:34 +11:00
Jonathan Brassow
ccebd4c415 md-new-param-to_sync_page_io
Add new parameter to 'sync_page_io'.

The new parameter allows us to distinguish between metadata and data
operations.  This becomes important later when we add the ability to
use separate devices for data and metadata.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14 09:14:33 +11:00
Jonathan Brassow
57b2caa394 md-new-param-to-calc_dev_sboffset
When we allow for separate devices for data and metadata
in a later patch, we will need to be able to calculate
the superblock offset based on more than the bdev.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14 09:14:33 +11:00
NeilBrown
7ebc0be7ff md: Be more careful about clearing flags bit in ->recovery
Setting ->recovery to 0 is generally not a good idea as it could clear
bits that shouldn't be cleared.  In particular, MD_RECOVERY_FROZEN
should only be cleared on explicit request from user-space.

So when we need to clear things, just clear the bits that need
clearing.

As there are a few different places which reap a resync process - and
some do an incomplte job - factor out the code for doing the from
md_check_recovery and call that function instead of open coding part
of it.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Jonathan Brassow <jbrassow@redhat.com>
2011-01-14 09:14:33 +11:00
NeilBrown
defad61a5b md: md_stop_writes requires mddev_lock.
As md_stop_writes manipulates the sync_thread and calls md_update_sb,
it need to be called with mddev_lock held.

In all internal cases it is, but the symbol is exported for dm-raid to
call and in that case the lock won't be help.
Do make an exported version which takes the lock, and an internal
version which does not.

Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:33 +11:00
Jonathan Brassow
43c73ca43b md/raid5: use sysfs_notify_dirent_safe to avoid NULL pointer
With the module parameter 'start_dirty_degraded' set,
raid5_spare_active() previously called sysfs_notify_dirent() with a NULL
argument (rdev->sysfs_state) when a rebuild finished.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2011-01-14 09:14:33 +11:00
NeilBrown
0ca69886a8 md: Ensure no IO request to get md device before it is properly initialised.
When an md device is in the process of coming on line it is possible
for an IO request (typically a partition table probe) to get through
before the array is fully initialised, which can cause unexpected
behaviour (e.g. a crash).

So explicitly record when the array is ready for IO and don't allow IO
through until then.

There is no possibility for a similar problem when the array is going
off-line as there must only be one 'open' at that time, and it is busy
off-lining the array and so cannot send IO requests.  So no memory
barrier is needed in md_stop()

This has been a bug since commit 409c57f380 in 2.6.30 which
introduced md_make_request.  Before then, each personality would
register its own make_request_fn when it was ready.
This is suitable for any stable kernel from 2.6.30.y onwards.

Cc: <stable@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by:  "Hawrylewicz Czarnowski, Przemyslaw" <przemyslaw.hawrylewicz.czarnowski@intel.com>
2011-01-14 09:14:33 +11:00
Joe Perches
067032bc62 md: Fix single printks with multiple KERN_<level>s
Noticed-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:14:33 +11:00
NeilBrown
6c98791014 md: fix regression resulting in delays in clearing bits in a bitmap
commit 589a594be1 (2.6.37-rc4) fixed a problem were md_thread would
sometimes call the ->run function at a bad time.

If an error is detected during array start up after the md_thread has
been started, the md_thread is killed.  This resulted in the ->run
function being called once.  However the array may not be in a state
that it is safe to call ->run.

However the fix imposed meant that  ->run was not called on a timeout.
This means that when an array goes idle, bitmap bits do not get
cleared promptly.  While the array is busy the bits will still be
cleared when appropriate so this is not very serious.  There is no
risk to data.

Change the test so that we only avoid calling ->run when the thread
is being stopped.  This more explicitly addresses the problem situation.

This is suitable for 2.6.37-stable and any -stable kernel to which
589a594be1 was applied.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-14 09:13:53 +11:00
NeilBrown
9d09e663d5 dm: raid456 basic support
This patch is the skeleton for the DM target that will be
the bridge from DM to MD (initially RAID456 and later RAID1).  It
provides a way to use device-mapper interfaces to the MD RAID456
drivers.

As with all device-mapper targets, the nominal public interfaces are the
constructor (CTR) tables and the status outputs (both STATUSTYPE_INFO
and STATUSTYPE_TABLE).  The CTR table looks like the following:

1: <s> <l> raid \
2:	<raid_type> <#raid_params> <raid_params> \
3:	<#raid_devs> <meta_dev1> <dev1> .. <meta_devN> <devN>

Line 1 contains the standard first three arguments to any device-mapper
target - the start, length, and target type fields.  The target type in
this case is "raid".

Line 2 contains the arguments that define the particular raid
type/personality/level, the required arguments for that raid type, and
any optional arguments.  Possible raid types include: raid4, raid5_la,
raid5_ls, raid5_rs, raid6_zr, raid6_nr, and raid6_nc.  (again, raid1 is
planned for the future.)  The list of required and optional parameters
is the same for all the current raid types.  The required parameters are
positional, while the optional parameters are given as key/value pairs.
The possible parameters are as follows:
 <chunk_size>		Chunk size in sectors.
 [[no]sync]		Force/Prevent RAID initialization
 [rebuild <idx>]	Rebuild the drive indicated by the index
 [daemon_sleep <ms>]	Time between bitmap daemon work to clear bits
 [min_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
 [max_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
 [max_write_behind <value>]		See '-write-behind=' (man mdadm)
 [stripe_cache <sectors>]		Stripe cache size for higher RAIDs

Line 3 contains the list of devices that compose the array in
metadata/data device pairs.  If the metadata is stored separately, a '-'
is given for the metadata device position.  If a drive has failed or is
missing at creation time, a '-' can be given for both the metadata and
data drives for a given position.

Examples:
# RAID4 - 4 data drives, 1 parity
# No metadata devices specified to hold superblock/bitmap info
# Chunk size of 1MiB
# (Lines separated for easy reading)
0 1960893648 raid \
	raid4 1 2048 \
	5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81

# RAID4 - 4 data drives, 1 parity (no metadata devices)
# Chunk size of 1MiB, force RAID initialization,
#	min recovery rate at 20 kiB/sec/disk
0 1960893648 raid \
        raid4 4 2048 min_recovery_rate 20 sync\
        5 - 8:17 - 8:33 - 8:49 - 8:65 - 8:81

Performing a 'dmsetup table' should display the CTR table used to
construct the mapping (with possible reordering of optional
parameters).

Performing a 'dmsetup status' will yield information on the state and
health of the array.  The output is as follows:
1: <s> <l> raid \
2:	<raid_type> <#devices> <1 health char for each dev> <resync_ratio>

Line 1 is standard DM output.  Line 2 is best shown by example:
	0 1960893648 raid raid4 5 AAAAA 2/490221568
Here we can see the RAID type is raid4, there are 5 devices - all of
which are 'A'live, and the array is 2/490221568 complete with recovery.

Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 20:00:02 +00:00
NeilBrown
99d03c141b dm: per target unplug callback support
Add per-target unplug callback support.

Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 20:00:02 +00:00
NeilBrown
9d357b0787 dm: introduce target callbacks and congestion callback
DM currently implements congestion checking by checking on congestion
in each component device.  For raid456 we need to also check if the
stripe cache is congested.

Add per-target congestion checker callback support.

Extending the target_callbacks structure with additional callback
functions allows for establishing multiple callbacks per-target (a
callback is also needed for unplug).

Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 20:00:01 +00:00
Chandra Seetharaman
4e2d19e46b dm mpath: delay activate_path retry on SCSI_DH_RETRY
This patch adds a user-configurable 'pg_init_delay_msecs' feature.  Use
this feature to specify the number of milliseconds to delay before
retrying scsi_dh_activate, when SCSI_DH_RETRY is returned.

SCSI Device Handlers return SCSI_DH_IMM_RETRY if we could retry
activation immediately and SCSI_DH_RETRY in cases where it is better to
retry after some delay.

Currently we immediately retry scsi_dh_activate irrespective of
SCSI_DH_IMM_RETRY and SCSI_DH_RETRY.

The 'pg_init_delay_msecs' feature may be provided during table create or
load, e.g.:
    dmsetup create --table "0 20971520 multipath 3 queue_if_no_path \
	pg_init_delay_msecs 2500 ..." mpatha

The default for 'pg_init_delay_msecs' is 2000 milliseconds.
Maximum configurable delay is 60000 milliseconds.  Specifying a
'pg_init_delay_msecs' of 0 will cause immediate retry.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 20:00:01 +00:00
Kiyoshi Ueda
052189a2ec dm: remove superfluous irq disablement in dm_request_fn
This patch changes spin_lock_irq() to spin_lock() in dm_request_fn().
This patch is just a clean-up and no functional change.

The spin_lock_irq() was leftover from the early request-based dm code,
where map_request() used to enable interrupts.
Since current map_request() never enables interrupts, we can change it
to spin_lock() to match the prior spin_unlock().

Auditing through the dm and block-layer code called from
map_request(), I confirmed all functions save/restore interrupt
status, so no function returning with interrupts enabled.
Also I haven't observed any problem on my test environment which
uses scsi and lpfc driver after heavy I/O testing with occasional
path down/up.

Added BUG_ON() to detect breakage in future.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 20:00:00 +00:00
Dan Carpenter
dbc883f157 dm log: use PTR_ERR value instead of ENOMEM
It's nicer to return the PTR_ERR() value instead of just returning
-ENOMEM.  In the current code the PTR_ERR() value is always equal to
-ENOMEM so this doesn't actually affect anything, but still...

In addition, dm_dirty_log_create() doesn't check for a specific -ENOMEM
return.  So this change is safe relative to potential for a non -ENOMEM
return in the future.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 20:00:00 +00:00
Mike Snitzer
b83b2f295a dm snapshot: avoid storing private suspended state
Use dm_suspended() rather than having each snapshot target maintain a
private 'suspended' flag in struct dm_snapshot.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:59 +00:00
Tejun Heo
239c8dd533 dm snapshot: persistent make metadata_wq multithreaded
metadata_wq serves on-stack work items from chunk_io().  Even if
multiple chunk_io() are simultaneously in progress, each is
independent and queued only once, so multithreaded workqueue can be
safely used.

Switch metadata_wq to multithread and flush the work item instead of
the workqueue in chunk_io().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:59 +00:00
Tejun Heo
9c4376de98 dm: use non reentrant workqueues if equivalent
kmirrord_wq, kcopyd_work and md->wq are created per dm instance and
serve only a single work item from the dm instance, so non-reentrant
workqueues would provide the same ordering guarantees as ordered ones
while allowing CPU affinity and use of the workqueues for other
purposes.  Switch them to non-reentrant workqueues.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:58 +00:00
Tejun Heo
4d4d66ab53 dm: convert workqueues to alloc_ordered
Convert all create[_singlethread]_work() users to the new
alloc[_ordered]_workqueue().  This conversion is mechanical and
doesn't introduce any behavior change.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:57 +00:00
Tejun Heo
f521f074ab dm stripe: switch from local workqueue to system_wq
kstriped only serves sc->kstriped_ws which runs dm_table_event().
This doesn't need to be executed from an ordered workqueue w/ rescuer.
Drop kstriped and use the system_wq instead.  While at it, rename
kstriped_ws to trigger_event so that it's consistent with other dm
modules.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:57 +00:00
Tejun Heo
d5ffa387e2 dm: dont use flush_scheduled_work
flush_scheduled_work() is being deprecated.  Flush the used work
directly instead.  In all dm targets, the only work which uses
system_wq is ->trigger_event.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:56 +00:00
Tejun Heo
fecec20e55 dm snapshot: remove unused dm_snapshot queued_bios_work
dm_snapshot->queued_bios_work isn't used.  Remove ->queued_bios[_work]
from dm_snapshot structure, the flush_queued_bios work function and
ksnapd workqueue.

The DM snapshot changes that were going to use the ksnapd workqueue were
either superseded (fix for origin write races) or never completed
(deallocation of invalid snapshot's memory via workqueue).

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:56 +00:00
Milan Broz
810b492375 dm ioctl: suppress needless warning messages
The device-mapper should not send warning messages to syslog
if a device is not found. This can be done by userspace
according to the returned dm-ioctl error code.

So move these messages to debug level and use rate limiting
to not flood syslog.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:55 +00:00
Milan Broz
3474578593 dm crypt: add loop aes iv generator
This patch adds a compatible implementation of the block
chaining mode used by the Loop-AES block device encryption
system (http://loop-aes.sourceforge.net/) designed
by Jari Ruusu.

It operates on full 512 byte sectors and uses CBC
with an IV derived from the sector number, the data and
optionally extra IV seed.

This means that after CBC decryption the first block of sector
must be tweaked according to decrypted data.

Loop-AES can use three encryption schemes:
 version 1: is plain aes-cbc mode (already compatible)
 version 2: uses 64 multikey scheme with own IV generator
 version 3: the same as version 2 with additional IV seed
            (it uses 65 keys, last key is used as IV seed)

The IV generator is here named lmk (Loop-AES multikey)
and for the cipher specification looks like: aes:64-cbc-lmk

Version 2 and 3 is recognised according to length
of provided multi-key string (which is just hexa encoded
"raw key" used in original Loop-AES ioctl).

Configuration of the device and decoding key string will
be done in userspace (cryptsetup).
(Loop-AES stores keys in gpg encrypted file, raw keys are
output of simple hashing of lines in this file).

Based on an implementation by Max Vozeler:
  http://article.gmane.org/gmane.linux.kernel.cryptoapi/3752/

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
CC: Max Vozeler <max@hinterhof.net>
2011-01-13 19:59:55 +00:00
Milan Broz
d1f9642381 dm crypt: add multi key capability
This patch adds generic multikey handling to be used
in following patch for Loop-AES mode compatibility.

This patch extends mapping table to optional keycount and
implements generic multi-key capability.

With more keys defined the <key> string is divided into
several <keycount> sections and these are used for tfms.

The tfm is used according to sector offset
(sector 0->tfm[0], sector 1->tfm[1], sector N->tfm[N modulo keycount])
(only power of two values supported for keycount here).

Because of tfms per-cpu allocation, this mode can be take
a lot of memory on large smp systems.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Max Vozeler <max@hinterhof.net>
2011-01-13 19:59:54 +00:00
Milan Broz
2dc5327d3a dm crypt: add post iv call to iv generator
IV (initialisation vector) can in principle depend not only
on sector but also on plaintext data (or other attributes).

Change IV generator interface to work directly with dmreq
structure to allow such dependence in generator.

Also add post() function which is called after the crypto
operation.

This allows tricky modification of decrypted data or IV
internals.

In asynchronous mode the post() can be called after
ctx->sector count was increased so it is needed
to add iv_sector copy directly to dmreq structure.
(N.B. dmreq always include only one sector in scatterlists)

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:54 +00:00
Milan Broz
20c82538e4 dm crypt: use io thread for reads only if mempool exhausted
If there is enough memory, code can directly submit bio
instead queing this operation in separate thread.

Try to alloc bio clone with GFP_NOWAIT and only if it
fails use separate queue (map function cannot block here).

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:53 +00:00
Andi Kleen
c029772125 dm crypt: scale to multiple cpus
Currently dm-crypt does all the encryption work for a single dm-crypt
mapping in a single workqueue. This does not scale well when multiple
CPUs are submitting IO at a high rate. The single CPU running the single
thread cannot keep up with the encryption and encrypted IO performance
tanks.

This patch changes the crypto workqueue to be per CPU. This means
that as long as the IO submitter (or the interrupt target CPUs
for reads) runs on different CPUs the encryption work will be also
parallel.

To avoid a bottleneck on the IO worker I also changed those to be
per-CPU threads.

There is still some shared data, so I suspect some bouncing
cache lines. But I haven't done a detailed study on that yet.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:53 +00:00
Milan Broz
7dbcd13741 dm crypt: simplify compatible table output
Rename cc->cipher_mode to cc->cipher_string and store the whole of the cipher
information so it can easily be printed when processing the DM_DEV_STATUS ioctl.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:52 +00:00
Jonathan Brassow
86a54a4802 dm log userspace: add version number to comms
This patch adds a 'version' field to the 'dm_ulog_request'
structure.

The 'version' field is taken from a portion of the unused
'padding' field in the 'dm_ulog_request' structure.  This
was done to avoid changing the size of the structure and
possibly disrupting backwards compatibility.

The version number will help notify user-space daemons
when a change has been made to the kernel/userspace
log API.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:52 +00:00
Jonathan Brassow
085ae0651b dm log userspace: group clear and mark requests
Allow the device-mapper log's 'mark' and 'clear' requests to be
grouped and processed in a batch.  This can significantly reduce the
amount of traffic going between the kernel and userspace (where the
processing daemon resides).

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:51 +00:00
Jonathan Brassow
909cc4fb48 dm log userspace: split flush queue
Split the 'flush_list', which contained a mix of both 'mark' and 'clear'
requests, into two distinct lists ('mark_list' and 'clear_list').

The device mapper log implementations (used by various DM targets) are
allowed to cache 'mark' and 'clear' requests until a 'flush' is
received.  Until now, these cached requests were kept in the same list.
They will now be put into distinct lists to facilitate group processing
of these requests (in the next patch).

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:50 +00:00
Mikulas Patocka
8d35d3e37e dm kcopyd: delay unplugging
Make kcopyd merge more I/O requests by using device unplugging.

Without this patch, each I/O request is dispatched separately to the device.
If the device supports tagged queuing, there are many small requests sent
to the device. To improve performance, this patch will batch as many requests
as possible, allowing the queue to merge consecutive requests, and send them
to the device at once.

In my tests (15k SCSI disk), this patch improves sequential write throughput:

  Sequential write throughput (chunksize of 4k, 32k, 512k)
  unpatched: 15.2, 18.5, 17.5 MB/s
  patched:   14.4, 22.6, 23.0 MB/s

In most common uses (snapshot or two-way mirror), kcopyd is only used for
two devices, one for reading and the other for writing, thus this optimization
is implemented only for two devices. The optimization may be extended to n-way
mirrors with some code complexity increase.

We keep track of two block devices to unplug (one for read and the
other for write) and unplug them when exiting "do_work" thread.  If
there are more devices used (in theory it could happen, in practice it
is rare), we unplug immediately.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:50 +00:00
Jonathan Brassow
4a038677df dm log userspace: trap all failed log construction errors
When constructing a mirror log, it is possible for the initial request
to fail for other reasons besides -ESRCH.  These must be handled too.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:49 +00:00
Milan Broz
69a8cfcda2 dm crypt: set key size early
Simplify key size verification (hexadecimal string) and
set key size early in constructor.

(Patch required by later changes.)

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:49 +00:00
Milan Broz
4a1aeb9829 dm: remove dm_mutex after bkl conversion
This patch replaces dm_mutex with _minor_lock in dm_blk_close()
and then removes it.

During the BKL conversion, commit 6e9624b8ca
(block: push down BKL into .open and .release) pushed lock_kernel()
down into dm_blk_open/close calls.
Commit 2a48fc0ab2
(block: autoconvert trivial BKL users to private mutex) converted it to a
local mutex, but _minor_lock is sufficient.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:48 +00:00
Mike Snitzer
5fc2ffeabb dm raid1: support discard
Enable discard support in the DM mirror target.
Also change an existing use of 'bvec' to 'addr' in the union.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:48 +00:00
Peter Jones
84c89557a3 dm ioctl: allow rename to fill empty uuid
Allow the uuid of a mapped device to be set after device creation.
Previously the uuid (which is optional) could only be set by
DM_DEV_CREATE.  If no uuid was supplied it could not be set later.

Sometimes it's necessary to create the device before the uuid is known,
and in such cases the uuid must be filled in after the creation.

This patch extends DM_DEV_RENAME to accept a uuid accompanied by
a new flag DM_UUID_FLAG.  This can only be done once and if no
uuid was previously supplied.  It cannot be used to change an
existing uuid.

DM_VERSION_MINOR is also bumped to 19 to indicate this interface
extension is available.

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:47 +00:00
Mikulas Patocka
d9bf0b508d dm io: remove BIO_RW_SYNCIO flag from kcopyd
Remove the REQ_SYNC flag to improve write throughput when writing
to the origin with a snapshot on the same device (using the CFQ I/O
scheduler).

Sequential write throughput (chunksize of 4k, 32k, 512k)
  unpatched:  8.5,  8.6,  9.3 MB/s
  patched:   15.2, 18.5, 17.5 MB/s

Snapshot exception reallocations are triggered by writes that are
usually async, so mark the associated dm_io_request as async as well.
This helps when using the CFQ I/O scheduler because it has separate
queues for sync and async I/O.  Async is optimized for throughput; sync
for latency.  With this change we're consciously favoring throughput over
latency.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-01-13 19:59:47 +00:00
Mike Snitzer
09c9d4c9b6 dm mpath: disable blk_abort_queue
Revert commit 224cb3e981
  dm: Call blk_abort_queue on failed paths

Multipath began to use blk_abort_queue() to allow for
lower latency path deactivation.  This was found to
cause list corruption:

   the cmd gets blk_abort_queued/timedout run on it and the scsi eh
   somehow is able to complete and run scsi_queue_insert while
   scsi_request_fn is still trying to process the request.

   https://www.redhat.com/archives/dm-devel/2010-November/msg00085.html

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: stable@kernel.org
2011-01-13 19:59:46 +00:00
Mike Snitzer
c217649bf2 dm: dont take i_mutex to change device size
No longer needlessly hold md->bdev->bd_inode->i_mutex when changing the
size of a DM device.  This additional locking is unnecessary because
i_size_write() is already protected by the existing critical section in
dm_swap_table().  DM already has a reference on md->bdev so the
associated bd_inode may be changed without lifetime concerns.

A negative side-effect of having held md->bdev->bd_inode->i_mutex was
that a concurrent DM device resize and flush (via fsync) would deadlock.
Dropping md->bdev->bd_inode->i_mutex eliminates this potential for
deadlock.  The following reproducer no longer deadlocks:
  https://www.redhat.com/archives/dm-devel/2009-July/msg00284.html

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
2011-01-13 19:53:46 +00:00
Linus Torvalds
275220f0fc Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits)
  block: ensure that completion error gets properly traced
  blktrace: add missing probe argument to block_bio_complete
  block cfq: don't use atomic_t for cfq_group
  block cfq: don't use atomic_t for cfq_queue
  block: trace event block fix unassigned field
  block: add internal hd part table references
  block: fix accounting bug on cross partition merges
  kref: add kref_test_and_get
  bio-integrity: mark kintegrityd_wq highpri and CPU intensive
  block: make kblockd_workqueue smarter
  Revert "sd: implement sd_check_events()"
  block: Clean up exit_io_context() source code.
  Fix compile warnings due to missing removal of a 'ret' variable
  fs/block: type signature of major_to_index(int) to major_to_index(unsigned)
  block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)
  cfq-iosched: don't check cfqg in choose_service_tree()
  fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors
  cdrom: export cdrom_check_events()
  sd: implement sd_check_events()
  sr: implement sr_check_events()
  ...
2011-01-13 10:45:01 -08:00
NeilBrown
bf572541ab md: fix regression with re-adding devices to arrays with no metadata
Commit 1a855a0606 (2.6.37-rc4) fixed a problem where devices were
re-added when they shouldn't be but caused a regression in a less
common case that means sometimes devices cannot be re-added when they
should be.

In particular, when re-adding a device to an array without metadata
we should always access the device, but after the above commit we
didn't.

This patch sets the In_sync flag in that case so that the re-add
succeeds.

This patch is suitable for any -stable kernel to which 1a855a0606 was
applied.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2011-01-12 09:03:35 +11:00
Jeff Moyer
b7908c1035 block: trace event block fix unassigned field
The "error" field in block_bio_complete is not assigned, leaving the memory area
uninitialized (keeping garbage data). Pass an additional tracepoint argument to
this event to initialize this field.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Li Zefan <lizf@cn.fujitsu.com>
CC: Alan.Brunelle@hp.com
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-01-07 08:43:55 +01:00
Linus Torvalds
7f8635cc9e Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cciss: fix cciss_revalidate panic
  block: max hardware sectors limit wrapper
  block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead
  blk-throttle: Correct the placement of smp_rmb()
  blk-throttle: Trim/adjust slice_end once a bio has been dispatched
  block: check for proper length of iov entries earlier in blk_rq_map_user_iov()
  drbd: fix for spin_lock_irqsave in endio callback
  drbd: don't recvmsg with zero length
2010-12-20 09:19:46 -08:00
Mike Snitzer
72d4cd9f38 block: max hardware sectors limit wrapper
Implement blk_limits_max_hw_sectors() and make
blk_queue_max_hw_sectors() a wrapper around it.

DM needs this to avoid setting queue_limits' max_hw_sectors and
max_sectors directly.  dm_set_device_limits() now leverages
blk_limits_max_hw_sectors() logic to establish the appropriate
max_hw_sectors minimum (PAGE_SIZE).  Fixes issue where DM was
incorrectly setting max_sectors rather than max_hw_sectors (which
caused dm_merge_bvec()'s max_hw_sectors check to be ineffective).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-17 08:36:01 +01:00
Martin K. Petersen
e692cb668f block: Deprecate QUEUE_FLAG_CLUSTER and use queue_limits instead
When stacking devices, a request_queue is not always available. This
forced us to have a no_cluster flag in the queue_limits that could be
used as a carrier until the request_queue had been set up for a
metadevice.

There were several problems with that approach. First of all it was up
to the stacking device to remember to set queue flag after stacking had
completed. Also, the queue flag and the queue limits had to be kept in
sync at all times. We got that wrong, which could lead to us issuing
commands that went beyond the max scatterlist limit set by the driver.

The proper fix is to avoid having two flags for tracking the same thing.
We deprecate QUEUE_FLAG_CLUSTER and use the queue limit directly in the
block layer merging functions. The queue_limit 'no_cluster' is turned
into 'cluster' to avoid double negatives and to ease stacking.
Clustering defaults to being enabled as before. The queue flag logic is
removed from the stacking function, and explicitly setting the cluster
flag is no longer necessary in DM and MD.

Reported-by: Ed Lin <ed.lin@promise.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-17 08:35:53 +01:00
NeilBrown
589a594be1 md: protect against NULL reference when waiting to start a raid10.
When we fail to start a raid10 for some reason, we call
md_unregister_thread to kill the thread that was created.

Unfortunately md_thread() will then make one call into the handler
(raid10d) even though md_wakeup_thread has not been called.  This is
not safe and as md_unregister_thread is called after mddev->private
has been set to NULL, it will definitely cause a NULL dereference.

So fix this at both ends:
 - md_thread should only call the handler if THREAD_WAKEUP has been
   set.
 - raid10 should call md_unregister_thread before setting things
   to NULL just like all the other raid modules do.

This is applicable to 2.6.35 and later.

Cc: stable@kernel.org
Reported-by: "Citizen" <citizen_lee@thecus.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 17:02:14 +11:00
NeilBrown
1a855a0606 md: fix bug with re-adding of partially recovered device.
With v0.90 metadata, a hot-spare does not become a full member of the
array until recovery is complete.  So if we re-add such a device to
the array, we know that all of it is as up-to-date as the event count
would suggest, and so it a bitmap-based recovery is possible.

However with v1.x metadata, the hot-spare immediately becomes a full
member of the array, but it record how much of the device has been
recovered.  If the array is stopped and re-assembled recovery starts
from this point.

When such a device is hot-added to an array we currently lose the 'how
much is recovered' information and incorrectly included it as a full
in-sync member (after bitmap-based fixup).
This is wrong and unsafe and could corrupt data.

So be more careful about setting saved_raid_disk - which is what
guides the re-adding of devices back into an array.
The new code matches the code in slot_store which does a similar
thing, which is encouraging.

This is suitable for any -stable kernel.

Reported-by: "Dailey, Nate" <Nate.Dailey@stratus.com>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 16:36:28 +11:00
NeilBrown
a035fc3e25 md: fix possible deadlock in handling flush requests.
As recorded in
    https://bugzilla.kernel.org/show_bug.cgi?id=24012

it is possible for a flush request through md to hang.  This is due to
an interaction between the recursion avoidance in
generic_make_request, the insistence in md of only having one flush
active at a time, and the possibility of dm (or md) submitting two
flush requests to a device from the one generic_make_request.

If a generic_make_request call into dm causes two flush requests to be
queued (as happens if the dm table has two targets - they get one
each), these two will be queued inside generic_make_request.

Assume they are for the same md device.
The first is processed and causes 1 or more flush requests to be sent
to lower devices.  These get queued within generic_make_request too.
Then the second flush to the md device gets handled and it blocks
waiting for the first flush to complete.  But it won't complete until
the two lower-device requests complete, and they haven't even been
submitted yet as they are on the generic_make_request queue.

The deadlock can be broken by using a separate thread to submit the
requests to lower devices.  md has such a thread readily available:
md_wq.

So use it to submit these requests.

Reported-by: Giacomo Catenazzi <cate@cateee.net>
Tested-by: Giacomo Catenazzi <cate@cateee.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 16:17:51 +11:00
NeilBrown
a7a07e6965 md: move code in to submit_flushes.
submit_flushes is called from exactly one place.
Move the code that is before and after that call into
submit_flushes.

This has not functional change, but will make the next patch
smaller and easier to follow.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 16:04:25 +11:00
NeilBrown
2b74e12e56 md: remove handling of flush_pending in md_submit_flush_data
None of the functions called between setting flush_pending to 1, and
atomic_dec_and_test can change flush_pending, or will anything
running in any other thread (as ->flush_bio is not NULL).  So the
atomic_dec_and_test will always succeed.
So remove the atomic_sec and the atomic_dec_and_test.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-12-09 15:59:01 +11:00
Jens Axboe
f30195c502 Merge branch 'cleanup-bd_claim' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into for-2.6.38/core 2010-11-27 19:49:18 +01:00
Darrick J. Wong
be20e6c67b md: Call blk_queue_flush() to establish flush/fua support
Before 2.6.37, the md layer had a mechanism for catching I/Os with the
barrier flag set, and translating the barrier into barriers for all
the underlying devices.  With 2.6.37, I/O barriers have become plain
old flushes, and the md code was updated to reflect this.  However,
one piece was left out -- the md layer does not tell the block layer
that it supports flushes or FUA access at all, which results in md
silently dropping flush requests.

Since the support already seems there, just add this one piece of
bookkeeping.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-24 16:40:33 +11:00
NeilBrown
8f9e0ee38f md/raid1: really fix recovery looping when single good device fails.
Commit 4044ba58dd supposedly fixed a
problem where if a raid1 with just one good device gets a read-error
during recovery, the recovery would abort and immediately restart in
an infinite loop.

However it depended on raid1_remove_disk removing the spare device
from the array.  But that does not happen in this case.  So add a test
so that in the 'recovery_disabled' case, the device will be removed.

This suitable for any kernel since 2.6.29 which is when
recovery_disabled was introduced.

Cc: stable@kernel.org
Reported-by: Sebastian Färber <faerber@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-24 16:39:46 +11:00
Justin Maggard
c26a44ed1e md: fix return value of rdev_size_change()
When trying to grow an array by enlarging component devices,
rdev_size_store() expects the return value of rdev_size_change() to be
in sectors, but the actual value is returned in KBs.

This functionality was broken by commit
     dd8ac336c1
so this patch is suitable for any kernel since 2.6.30.

Cc: stable@kernel.org
Signed-off-by: Justin Maggard <jmaggard10@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-24 16:36:17 +11:00
Mike Snitzer
d07335e51d block: Rename "block_remap" tracepoint to "block_bio_remap" to clarify the event.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-16 12:53:39 +01:00
Tejun Heo
d4d7762995 block: clean up blkdev_get() wrappers and their users
After recent blkdev_get() modifications, open_by_devnum() and
open_bdev_exclusive() are simple wrappers around blkdev_get().
Replace them with blkdev_get_by_dev() and blkdev_get_by_path().

blkdev_get_by_dev() is identical to open_by_devnum().
blkdev_get_by_path() is slightly different in that it doesn't
automatically add %FMODE_EXCL to @mode.

All users are converted.  Most conversions are mechanical and don't
introduce any behavior difference.  There are several exceptions.

* btrfs now sets FMODE_EXCL in btrfs_device->mode, so there's no
  reason to OR it explicitly on blkdev_put().

* gfs2, nilfs2 and the generic mount_bdev() now set FMODE_EXCL in
  sb->s_mode.

* With the above changes, sb->s_mode now always should contain
  FMODE_EXCL.  WARN_ON_ONCE() added to kill_block_super() to detect
  errors.

The new blkdev_get_*() functions are with proper docbook comments.
While at it, add function description to blkdev_get() too.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Joern Engel <joern@lazybastard.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: reiserfs-devel@vger.kernel.org
Cc: xfs-masters@oss.sgi.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:18 +01:00
Tejun Heo
e525fd89d3 block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.

* blkdev_get/put() are the primary open and close functions.

* bd_claim/release() deal with exclusive open.

* open/close_bdev_exclusive() are combination of open and claim and
  the other way around, respectively.

* bd_link/unlink_disk_holder() to create and remove holder/slave
  symlinks.

* open_by_devnum() wraps bdget() + blkdev_get().

The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access.  Reorganize the interface such that,

* blkdev_get() is extended to include exclusive access management.
  @holder argument is added and, if is @FMODE_EXCL specified, it will
  gain exclusive access atomically w.r.t. other exclusive accesses.

* blkdev_put() is similarly extended.  It now takes @mode argument and
  if @FMODE_EXCL is set, it releases an exclusive access.  Also, when
  the last exclusive claim is released, the holder/slave symlinks are
  removed automatically.

* bd_claim/release() and close_bdev_exclusive() are no longer
  necessary and either made static or removed.

* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
  is no longer necessary and removed.

* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
  and blkdev_get().  It also has an unexpected extra bdev_read_only()
  test which probably should be moved into blkdev_get().

* open_by_devnum() is modified to take @holder argument and pass it to
  blkdev_get().

Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should).  This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.

open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features.  Well, let's leave them for another day.

Most conversions are straight-forward.  drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 11:55:17 +01:00
Tejun Heo
e09b457bdb block: simplify holder symlink handling
Code to manage symlinks in /sys/block/*/{holders|slaves} are overly
complex with multiple holder considerations, redundant extra
references to all involved kobjects, unused generic kobject holder
support and unnecessary mixup with bd_claim/release functionalities.

Strip it down to what's necessary (single gendisk holder) and make it
use a separate interface.  This is a step for cleaning up
bd_claim/release.  This patch makes dm-table slightly more complex but
it will be simplified again with further changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
2010-11-13 11:55:17 +01:00
Mike Snitzer
77304d2aba block: read i_size with i_size_read()
Convert direct reads of an inode's i_size to using i_size_read().

i_size_{read,write} use a seqcount to protect reads from accessing
incomple writes.  Concurrent i_size_write()s require mutual exclussion
to protect the seqcount that is used by i_size_{read,write}.  But
i_size_read() callers do not need to use additional locking.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: NeilBrown <neilb@suse.de>
Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-10 14:40:53 +01:00
NeilBrown
f3ac8bf7ce md: tidy up device searches in read_balance.
The code for searching through the device list to read-balance in
raid1 is rather clumsy and hard to follow.  Try to simplify it a bit.

No important functionality change here.


Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29 16:40:33 +11:00
NeilBrown
046abeede7 md/raid1: fix some typos in comments.
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29 16:40:33 +11:00
NeilBrown
9b19553e0b md/raid1: discard unused variable.
This structure field (flushing_bio_list) is never used, so remove it.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29 16:40:33 +11:00
NeilBrown
be2a2656ee md: unplug writes to external bitmaps.
When writing to an 'external' bitmap we don't currently unplug the
device before waiting, so we can get a 3msec delay each time;
So use REQ_UNPLUG to force and unplug.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29 16:40:32 +11:00
NeilBrown
a167f66324 md: use separate bio pool for each md device.
bio_clone and bio_alloc allocate from a common bio pool.
If an md device is stacked with other devices that use this pool, or under
something like swap which uses the pool, then the multiple calls on
the pool can cause deadlocks.

So allocate a local bio pool for each md array and use that rather
than the common pool.

This pool is used both for regular IO and metadata updates.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:36:15 +11:00
NeilBrown
2b193363ef md: change type of first arg to sync_page_io.
Currently sync_page_io takes a 'bdev'.
Every caller passes 'rdev->bdev'.
We will soon want another field out of the rdev in sync_page_io,
So just pass the rdev instead of the bdev out of it.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:36:11 +11:00
NeilBrown
1c4588e9c1 md/raid1: perform mem allocation before disabling writes during resync.
Though this mem alloc is GFP_NOIO an so will not deadlock, it seems
better to do the allocation before 'raise_barrier' which stops any IO
requests while the resync proceeds.

raid10 always uses this order, so it is at least consistent to do the
same in raid1.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:36:09 +11:00
NeilBrown
6746557f03 md: use bio_kmalloc rather than bio_alloc when failure is acceptable.
bio_alloc can never fail (as it uses a mempool) but an block
indefinitely, especially if the caller is holding a reference to a
previously allocated bio.

So these to places which both handle failure and hold multiple bios
should not use bio_alloc, they should use bio_kmalloc.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:36:06 +11:00
NeilBrown
4e78064f42 md: Fix possible deadlock with multiple mempool allocations.
It is not safe to allocate from a mempool while holding an item
previously allocated from that mempool as that can deadlock when the
mempool is close to exhaustion.

So don't use a bio list to collect the bios to write to multiple
devices in raid1 and raid10.
Instead queue each bio as it becomes available so an unplug will
activate all previously allocated bios and so a new bio has a chance
of being allocated.

This means we must set the 'remaining' count to '1' before submitting
any requests, then when all are submitted, decrement 'remaining' and
possible handle the write completion at that point.

Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com>
Tested-by: Torsten Kaiser <just.for.lkml@googlemail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:34:07 +11:00
Tejun Heo
e804ac780e md: fix and update workqueue usage
Workqueue usage in md has two problems.

* Flush can be used during or depended upon by memory reclaim, but md
  uses the system workqueue for flush_work which may lead to deadlock.

* md depends on flush_scheduled_work() to achieve exclusion against
  completion of removal of previous instances.  flush_scheduled_work()
  may incur unexpected amount of delay and is scheduled to be removed.

This patch adds two workqueues to md - md_wq and md_misc_wq.  The
former is guaranteed to make forward progress under memory pressure
and serves flush_work.  The latter serves as the flush domain for
other works.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:32:29 +11:00
NeilBrown
57dab0bdf6 md: use sector_t in bitmap_get_counter
bitmap_get_counter returns the number of sectors covered
by the counter in a pass-by-reference variable.
In some cases this can be very large, so make it a sector_t
for safety.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:32:26 +11:00
NeilBrown
4b532c9b8c md: remove md_mutex locking.
lock_kernel calls were recently pushed down into open/release
functions.
md doesn't need that protection.
Then the BKL calls were change to md_mutex.  We don't need those
either.
So remove it all.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28 17:30:21 +11:00
NeilBrown
d97a41dc9c md: Fix regression with raid1 arrays without persistent metadata.
A RAID1 which has no persistent metadata, whether internal or
external, will hang on the first write.
This is caused by commit  070dc6dd71
In that case, MD_CHANGE_PENDING never gets cleared.

So during md_update_sb, is neither persistent or external,
clear MD_CHANGE_PENDING.

This is suitable for 2.6.36-stable.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-10-28 17:30:20 +11:00
Andrew Morton
ca1cab37d9 workqueues: s/ON_STACK/ONSTACK/
Silly though it is, completions and wait_queue_heads use foo_ONSTACK
(COMPLETION_INITIALIZER_ONSTACK, DECLARE_COMPLETION_ONSTACK,
__WAIT_QUEUE_HEAD_INIT_ONSTACK and DECLARE_WAIT_QUEUE_HEAD_ONSTACK) so I
guess workqueues should do the same thing.

s/INIT_WORK_ON_STACK/INIT_WORK_ONSTACK/
s/INIT_DELAYED_WORK_ON_STACK/INIT_DELAYED_WORK_ONSTACK/

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:14 -07:00
Linus Torvalds
a2887097f2 Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits)
  xen-blkfront: disable barrier/flush write support
  Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c
  block: remove BLKDEV_IFL_WAIT
  aic7xxx_old: removed unused 'req' variable
  block: remove the BH_Eopnotsupp flag
  block: remove the BLKDEV_IFL_BARRIER flag
  block: remove the WRITE_BARRIER flag
  swap: do not send discards as barriers
  fat: do not send discards as barriers
  ext4: do not send discards as barriers
  jbd2: replace barriers with explicit flush / FUA usage
  jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
  jbd: replace barriers with explicit flush / FUA usage
  nilfs2: replace barriers with explicit flush / FUA usage
  reiserfs: replace barriers with explicit flush / FUA usage
  gfs2: replace barriers with explicit flush / FUA usage
  btrfs: replace barriers with explicit flush / FUA usage
  xfs: replace barriers with explicit flush / FUA usage
  block: pass gfp_mask and flags to sb_issue_discard
  dm: convey that all flushes are processed as empty
  ...
2010-10-22 17:07:18 -07:00
Linus Torvalds
e9dd2b6837 Merge branch 'for-2.6.37/core' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.37/core' of git://git.kernel.dk/linux-2.6-block: (39 commits)
  cfq-iosched: Fix a gcc 4.5 warning and put some comments
  block: Turn bvec_k{un,}map_irq() into static inline functions
  block: fix accounting bug on cross partition merges
  block: Make the integrity mapped property a bio flag
  block: Fix double free in blk_integrity_unregister
  block: Ensure physical block size is unsigned int
  blkio-throttle: Fix possible multiplication overflow in iops calculations
  blkio-throttle: limit max iops value to UINT_MAX
  blkio-throttle: There is no need to convert jiffies to milli seconds
  blkio-throttle: Fix link failure failure on i386
  blkio: Recalculate the throttled bio dispatch time upon throttle limit change
  blkio: Add root group to td->tg_list
  blkio: deletion of a cgroup was causes oops
  blkio: Do not export throttle files if CONFIG_BLK_DEV_THROTTLING=n
  block: set the bounce_pfn to the actual DMA limit rather than to max memory
  block: revert bad fix for memory hotplug causing bounces
  Fix compile error in blk-exec.c for !CONFIG_DETECT_HUNG_TASK
  block: set the bounce_pfn to the actual DMA limit rather than to max memory
  block: Prevent hang_check firing during long I/O
  cfq: improve fsync performance for small files
  ...

Fix up trivial conflicts due to __rcu sparse annotation in include/linux/genhd.h
2010-10-22 17:00:32 -07:00
Linus Torvalds
092e0e7e52 Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek
2010-10-22 10:52:56 -07:00
Linus Torvalds
c37927d435 Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  block: autoconvert trivial BKL users to private mutex
  drivers: autoconvert trivial BKL users to private mutex
  ipmi: autoconvert trivial BKL users to private mutex
  mac: autoconvert trivial BKL users to private mutex
  mtd: autoconvert trivial BKL users to private mutex
  scsi: autoconvert trivial BKL users to private mutex

Fix up trivial conflicts (due to addition of private mutex right next to
deletion of a version string) in drivers/char/pcmcia/cm40[04]0_cs.c
2010-10-22 10:49:54 -07:00
Jens Axboe
fa251f8990 Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier
Conflicts:
	block/blk-core.c
	drivers/block/loop.c
	mm/swapfile.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-19 09:13:04 +02:00
Arnd Bergmann
6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Vasiliy Kulikov
5c04f5512f md: check return code of read_sb_page
Function read_sb_page may return ERR_PTR(...). Check for it.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-07 12:02:50 +11:00
NeilBrown
db8d9d3591 md/raid1: minor bio initialisation improvements.
When performing a resync we pre-allocate some bios and repeatedly use
them.  This requires us to re-initialise them each time.
One field (bi_comp_cpu) and some flags weren't being initiaised
reliably.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-07 12:00:50 +11:00
NeilBrown
7571ae887d md/raid1: avoid overflow in raid1 resync when bitmap is in use.
bitmap_start_sync returns - via a pass-by-reference variable - the
number of sectors before we need to check with the bitmap again.
Since commit ef42567335 this number can be substantially larger,
2^27 is a common value.

Unfortunately it is an 'int' and so when raid1.c:sync_request shifts
it 9 places to the left it becomes 0.  This results in a zero-length
read which the scsi layer justifiably complains about.

This patch just removes the shift so the common case becomes safe with
a trivially-correct patch.

In the next merge window we will convert this 'int' to a 'sector_t'

Reported-by: "George Spelvin" <linux@horizon.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-07 11:54:46 +11:00
Arnd Bergmann
2a48fc0ab2 block: autoconvert trivial BKL users to private mutex
The block device drivers have all gained new lock_kernel
calls from a recent pushdown, and some of the drivers
were already using the BKL before.

This turns the BKL into a set of per-driver mutexes.
Still need to check whether this is safe to do.

file=$1
name=$2
if grep -q lock_kernel ${file} ; then
    if grep -q 'include.*linux.mutex.h' ${file} ; then
            sed -i '/include.*<linux\/smp_lock.h>/d' ${file}
    else
            sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file}
    fi
    sed -i ${file} \
        -e "/^#include.*linux.mutex.h/,$ {
                1,/^\(static\|int\|long\)/ {
                     /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex);

} }"  \
    -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \
    -e '/[      ]*cycle_kernel_lock();/d'
else
    sed -i -e '/include.*\<smp_lock.h\>/d' ${file}  \
                -e '/cycle_kernel_lock()/d'
fi

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2010-10-05 15:01:10 +02:00
NeilBrown
ddcf3522cf md: fix v1.x metadata update when a disk is missing.
If an array with 1.x metadata is assembled with the last disk missing,
md doesn't properly record the fact that the disk was missing.

This is unlikely to cause a real problem as the event count will be
different to the count on the missing disk so it won't be included in
the array.  However it could still cause confusion.

So make sure we clear all the relevant slots, not just the early ones.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-09-17 13:53:28 +10:00
NeilBrown
126925c090 md: call md_update_sb even for 'external' metadata arrays.
Now that we depend on md_update_sb to clear variable bits in
mddev->flags (rather than trying not to set them) it is important to
always call md_update_sb when appropriate.

md_check_recovery has this job but explicitly avoids it for ->external
metadata arrays.  This is not longer appropraite, or needed.

However we do want to avoid taking the mddev lock if only
MD_CHANGE_PENDING is set as that is not cleared by md_update_sb for
external-metadata arrays.

Reported-by:  "Kwolek, Adam" <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-09-17 13:53:13 +10:00
Martin K. Petersen
c8bf133682 Consolidate min_not_zero
We have several users of min_not_zero, each of them using their own
definition.  Move the define to kernel.h.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
2010-09-10 20:07:38 +02:00
Mike Snitzer
b372d360df dm: convey that all flushes are processed as empty
Rename __clone_and_map_flush to __clone_and_map_empty_flush for added
clarity.

Simplify logic associated with REQ_FLUSH conditionals.

Introduce a BUG_ON() and add a few more helpful comments to the code
so that it is clear that all flushes are empty.

Cleanup __split_and_process_bio() so that an empty flush isn't processed
by a 'sector_count' focused while loop.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:38 +02:00
Kiyoshi Ueda
05447420f9 dm: fix locking context in queue_io()
Now queue_io() is called from dec_pending(), which may be called with
interrupts disabled, so queue_io() must not enable interrupts
unconditionally and must save/restore the current interrupts status.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:38 +02:00
Tejun Heo
6a8736d10c dm: relax ordering of bio-based flush implementation
Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA doesn't mandate any ordering
against other bio's.  This patch relaxes ordering around flushes.

* A flush bio is no longer deferred to workqueue directly.  It's
  processed like other bio's but __split_and_process_bio() uses
  md->flush_bio as the clone source.  md->flush_bio is initialized to
  empty flush during md initialization and shared for all flushes.

* As a flush bio now travels through the same execution path as other
  bio's, there's no need for dedicated error handling path either.  It
  can use the same error handling path in dec_pending().  Dedicated
  error handling removed along with md->flush_error.

* When dec_pending() detects that a flush has completed, it checks
  whether the original bio has data.  If so, the bio is queued to the
  deferred list w/ REQ_FLUSH cleared; otherwise, it's completed.

* As flush sequencing is handled in the usual issue/completion path,
  dm_wq_work() no longer needs to handle flushes differently.  Now its
  only responsibility is re-issuing deferred bio's the same way as
  _dm_request() would.  REQ_FLUSH handling logic including
  process_flush() is dropped.

* There's no reason for queue_io() and dm_wq_work() write lock
  dm->io_lock.  queue_io() now only uses md->deferred_lock and
  dm_wq_work() read locks dm->io_lock.

* bio's no longer need to be queued on the deferred list while a flush
  is in progress making DMF_QUEUE_IO_TO_THREAD unncessary.  Drop it.

This avoids stalling the device during flushes and simplifies the
implementation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:38 +02:00
Tejun Heo
29e4013de7 dm: implement REQ_FLUSH/FUA support for request-based dm
This patch converts request-based dm to support the new REQ_FLUSH/FUA.

The original request-based flush implementation depended on
request_queue blocking other requests while a barrier sequence is in
progress, which is no longer true for the new REQ_FLUSH/FUA.

In general, request-based dm doesn't have infrastructure for cloning
one source request to multiple targets, but the original flush
implementation had a special mostly independent path which can issue
flushes to multiple targets and sequence them.  However, the
capability isn't currently in use and adds a lot of complexity.
Moreoever, it's unlikely to be useful in its current form as it
doesn't make sense to be able to send out flushes to multiple targets
when write requests can't be.

This patch rips out special flush code path and deals handles
REQ_FLUSH/FUA requests the same way as other requests.  The only
special treatment is that REQ_FLUSH requests use the block address 0
when finding target, which is enough for now.

* added BUG_ON(!dm_target_is_valid(ti)) in dm_request_fn() as
  suggested by Mike Snitzer

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Tested-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:38 +02:00
Tejun Heo
d87f4c14f2 dm: implement REQ_FLUSH/FUA support for bio-based dm
This patch converts bio-based dm to support REQ_FLUSH/FUA instead of
now deprecated REQ_HARDBARRIER.

* -EOPNOTSUPP handling logic dropped.

* Preflush is handled as before but postflush is dropped and replaced
  with passing down REQ_FUA to member request_queues.  This replaces
  one array wide cache flush w/ member specific FUA writes.

* __split_and_process_bio() now calls __clone_and_map_flush() directly
  for flushes and guarantees all FLUSH bio's going to targets are zero
`  length.

* It's now guaranteed that all FLUSH bio's which are passed onto dm
  targets are zero length.  bio_empty_barrier() tests are replaced
  with REQ_FLUSH tests.

* Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes.

* Dropped unlikely() around REQ_FLUSH tests.  Flushes are not unlikely
  enough to be marked with unlikely().

* Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue
  doesn't support cache flushing.  Advertise REQ_FLUSH | REQ_FUA
  capability.

* Request based dm isn't converted yet.  dm_init_request_based_queue()
  resets flush support to 0 for now.  To avoid disturbing request
  based dm code, dm->flush_error is added for bio based dm while
  requested based dm continues to use dm->barrier_error.

Lightly tested linear, stripe, raid1, snap and crypt targets.  Please
proceed with caution as I'm not familiar with the code base.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: dm-devel@redhat.com
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:38 +02:00
Tejun Heo
e9c7469bb4 md: implment REQ_FLUSH/FUA support
This patch converts md to support REQ_FLUSH/FUA instead of now
deprecated REQ_HARDBARRIER.  In the core part (md.c), the following
changes are notable.

* Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with
  processing of other requests and thus there is no reason to mark the
  queue congested while FLUSH/FUA is in progress.

* REQ_FLUSH/FUA failures are final and its users don't need retry
  logic.  Retry logic is removed.

* Preflush needs to be issued to all member devices but FUA writes can
  be handled the same way as other writes - their processing can be
  deferred to request_queue of member devices.  md_barrier_request()
  is renamed to md_flush_request() and simplified accordingly.

For linear, raid0 and multipath, the core changes are enough.  raid1,
5 and 10 need the following conversions.

* raid1: Handling of FLUSH/FUA bio's can simply be deferred to
  request_queues of member devices.  Barrier related logic removed.

* raid5: Queue draining logic dropped.  FUA bit is propagated through
  biodrain and stripe resconstruction such that all the updated parts
  of the stripe are written out with FUA writes if any of the dirtying
  writes was FUA.  preread_active_stripes handling in make_request()
  is updated as suggested by Neil Brown.

* raid10: FUA bit needs to be propagated to write clones.

linear, raid0, 1, 5 and 10 tested.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:38 +02:00
Tejun Heo
4913efe456 block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()
Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA
requests.  Deprecate barrier.  All REQ_HARDBARRIERs are failed with
-EOPNOTSUPP and blk_queue_ordered() is replaced with simpler
blk_queue_flush().

blk_queue_flush() takes combinations of REQ_FLUSH and FUA.  If a
device has write cache and can flush it, it should set REQ_FLUSH.  If
the device can handle FUA writes, it should also set REQ_FUA.

All blk_queue_ordered() users are converted.

* ORDERED_DRAIN is mapped to 0 which is the default value.
* ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH.
* ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:36 +02:00
NeilBrown
070dc6dd71 md: resolve confusion of MD_CHANGE_CLEAN
MD_CHANGE_CLEAN is used for two different purposes and this leads to
confusion.
One of the purposes is largely mirrored by MD_CHANGE_PENDING which is
not used for anything else, so have MD_CHANGE_PENDING take over that
purpose fully.

The two purposes are:
 1/ tell md_update_sb that an update is needed and that it is just a
   clean/dirty transition.
 2/ tell user-space that an transition from clean to dirty is pending
    (something wants to write), and tell te kernel (by clearin the
    flag) that the transition is OK.

The first purpose remains wit MD_CHANGE_CLEAN, the second is moved
fully to MD_CHANGE_PENDING.

This means that various places which conditionally set or cleared
MD_CHANGE_CLEAN no longer need to be conditional.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-30 18:06:21 +10:00
Dan Williams
bd52b74626 md: don't clear MD_CHANGE_CLEAN in md_update_sb() for external arrays
If this bit is cleared in md_update_sb() the kernel will allow writes to the
array if userspace triggers md_allow_write(), e.g. through stripe_cache_size,
when mdmon is not active.  When mdmon is active the array transitions to
active-idle bypassing write-pending, setting up a race for mdmon to set the
array clean before a write arrives.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-30 18:06:20 +10:00
NeilBrown
7c44ece988 Move .gitignore from drivers/md to lib/raid6
Another missing bit of the raid6 -> /lib move.

Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-30 17:35:52 +10:00
NeilBrown
2c7d46ec19 md raid-1/10 Fix bio_rw bit manipulations again
commit 7b6d91daee changed the behaviour
of a few variables in raid1 and raid10 from flags to bit-sets, but
left them as type 'bool' so they did not work.

Change them (back) to unsigned long.
(historical note: see 1ef04fefe2)

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Jiri Slaby <jslaby@suse.cz> and many others
2010-08-18 16:16:05 +10:00
NeilBrown
6b96562054 md: provide appropriate return value for spare_active functions.
md_check_recovery expects ->spare_active to return 'true' if any
spares were activated, but none of them do, so the consequent change
in 'degraded' is not notified through sysfs.

So count the number of spares activated, subtract it from 'degraded'
just once, and return it.

Reported-by: Adrian Drzewiecki <adriand@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-18 12:04:32 +10:00
Adrian Drzewiecki
e6ffbcb6cd md: Notify sysfs when RAID1/5/10 disk is In_sync.
When RAID1 is done syncing disks, it'll update the state
of synced rdevs to In_sync. But it neglected to notify
sysfs that the attribute changed. So any programs that
are waiting for an rdev's state to change will not be
woken.

(raid5/raid10 added by neilb)

Signed-off-by: Adrian Drzewiecki <adriand@vmware.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-18 11:49:02 +10:00
NeilBrown
3a3a5ddb7a Update recovery_offset even when external metadata is used.
The update of ->recovery_offset in sync_sbs is appropriate even then external
metadata is in use.  However sync_sbs is only called when native
metadata is used.

So move that update in to the top of md_update_sb (which is the only
caller of sync_sbs) before the test on ->external.

This moves the update out of ->write_lock protection, but those fields
only need ->reconfig_mutex protection which they still have.

Also move the test on ->persistent up to where ->external is set as
for metadata update purposes they are the same.

Clear MD_CHANGE_DEVS and MD_CHANGE_CLEAN as they can only be confusing
if ->external is set or ->persistent isn't.

Finally move the update of ->utime down as it is only relevent (like
the ->events update) for native metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: "Kwolek, Adam" <adam.kwolek@intel.com>
2010-08-18 11:39:38 +10:00
Mike Snitzer
959eb4e559 dm mpath: support discard
Enable discard support in the DM multipath target.

This discard support depends on a few discard-specific fixes to the
block layer's request stacking driver methods.

Discard requests are optional so don't allow a failed discard to trigger
path failures.  If there is a real problem with a given path the
barriers associated with the discard (either before or after the
discard) will cause path failure.  That said, unconditionally passing
discard failures up the stack is not ideal.  This must be fixed once DM
has more information about the nature of the underlying storage failure.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
2010-08-12 04:14:32 +01:00
Mikulas Patocka
7b76ec11fe dm stripe: support discards
The DM core will submit a discard bio to the stripe target for each
stripe in a striped DM device.  The stripe target will determine
stripe-specific portions of the supplied bio to be remapped into
individual (at most 'num_discard_requests' extents).  If a given
stripe-specific discard bio doesn't touch a particular stripe the bio
will be dropped.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:26 +01:00
Mike Snitzer
a79245b3e5 dm: split discard requests on target boundaries
Update __clone_and_map_discard to loop across all targets in a DM
device's table when it processes a discard bio.  If a discard crosses a
target boundary it must be split accordingly.

Update __issue_target_requests and __issue_target_request to allow a
cloned discard bio to have a custom start sector and size.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:24 +01:00
Mikulas Patocka
c96053b767 dm stripe: optimize sector division
Optimize sector division: If the number of stripes is a power of two,
we can do shift and mask instead of division.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:21 +01:00
Mikulas Patocka
65988525ab dm stripe: move sector translation to a function
Move sector to stripe translation into a function.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:14 +01:00
Mike Snitzer
38e1b257fd dm: error return error for discards
Have the error target respond to a discard request with a hard -EIO
rather than fail the request with -EOPNOTSUPP.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:14 +01:00
Mike Snitzer
3fd5d48027 dm delay: support discard
Enable discard support for the delay target.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:13 +01:00
Mike Snitzer
f8facb61b5 dm: zero silently drop discards
Have the zero target silently drop a discard rather than fail the
request with -EOPNOTSUPP.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:12 +01:00
Alasdair G Kergon
b441a262e7 dm: use dm_target_offset macro
Use new dm_target_offset() macro to avoid most references to ti->begin
in dm targets.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:11 +01:00
Mike Snitzer
56a67df766 dm: factor out max_io_len_target_boundary
Split max_io_len_target_boundary out of max_io_len so that the discard
support can make use of it without duplicating max_io_len code.

Avoiding max_io_len's split_io logic enables DM's discard support to
submit the entire discard request to a target.  But discards must still
be split on target boundaries.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:10 +01:00
Mike Snitzer
06a426cee9 dm: use common __issue_target_request for flush and discard support
Rename __flush_target to __issue_target_request now that it is used to
issue both flush and discard requests.

Introduce __issue_target_requests as a convenient wrapper to
__issue_target_request 'num_flush_requests' or 'num_discard_requests'
times per target.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:09 +01:00
Mike Snitzer
5ae89a8720 dm: linear support discard
Allow discards to be passed through to linear mappings if at least one
underlying device supports it.  Discards will be forwarded only to
devices that support them.

A target that supports discards should set num_discard_requests to
indicate how many times each discard request must be submitted to it.

Verify table's underlying devices support discards prior to setting the
associated DM device as capable of discards (via QUEUE_FLAG_DISCARD).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Joe Thornber <thornber@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:08 +01:00
Milan Broz
5ebaee6d29 dm crypt: simplify crypt_ctr
Allocate cipher strings indpendently of struct crypt_config and move
cipher parsing and allocation into a separate function to prepare for
supporting the cryptoapi format e.g. "xts(aes)".

No functional change in this patch.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:07 +01:00
Milan Broz
28513fccf0 dm crypt: simplify crypt_config destruction logic
Use just one label and reuse common destructor for crypt target.

Parse remaining argv arguments in logic order.

Also do not ignore error values from IV init and set key functions.

No functional change in this patch except changed return codes
based on above.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:06 +01:00
Peter Rajnoha
7e507eb643 dm: allow autoloading of dm mod
Add devname:mapper/control and MAPPER_CTRL_MINOR module alias
to support dm-mod module autoloading.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:05 +01:00
Mike Snitzer
57cba5d365 dm: rename map_info flush_request to target_request_nr
'target_request_nr' is a more generic name that reflects the fact that
it will be used for both flush and discard support.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:04 +01:00
Will Drewry
26803b9f06 dm ioctl: refactor dm_table_complete
This change unifies the various checks and finalization that occurs on a
table prior to use.  By doing so, it allows table construction without
traversing the dm-ioctl interface.

Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:03 +01:00
Mikulas Patocka
b1d5552838 dm snapshot: implement merge
Implement merge method for the snapshot origin to improve read
performance.

Without merge method, dm asks the upper layers to submit smallest possible
bios --- one page. Submitting such small bios impacts performance negatively
when reading or writing the origin device.

Without this patch, CPU consumption when reading the origin on lvm on md-raid0
was 6 to 12%, with this patch, it drops to 1 to 4%.

Note: in my testing, it actually degraded performance in some settings, I
traced it to Maxtor disks having problems with > 512-sector requests.
Reducing the number of sectors to /sys/block/sd*/queue/max_sectors_kb to
256 fixed the read performance. I think we don't have to care about weird
disks that actually degrade performance because of large requests being
sent to them.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:02 +01:00
Mike Snitzer
4a0b4ddf26 dm: do not initialise full request queue when bio based
Change bio-based mapped devices no longer to have a fully initialized
request_queue (request_fn, elevator, etc).  This means bio-based DM
devices no longer register elevator sysfs attributes ('iosched/' tree
or 'scheduler' other than "none").

In contrast, a request-based DM device will continue to have a full
request_queue and will register elevator sysfs attributes.  Therefore
a user can determine a DM device's type by checking if elevator sysfs
attributes exist.

First allocate a minimalist request_queue structure for a DM device
(needed for both bio and request-based DM).

Initialization of a full request_queue is deferred until it is known
that the DM device is request-based, at the end of the table load
sequence.

Factor DM device's request_queue initialization:
- common to both request-based and bio-based into dm_init_md_queue().
- specific to request-based into dm_init_request_based_queue().

The md->type_lock mutex is used to protect md->queue, in addition to
md->type, during table_load().

A DM device's first table_load will establish the immutable md->type.
But md->queue initialization, based on md->type, may fail at that time
(because blk_init_allocated_queue cannot allocate memory).  Therefore
any subsequent table_load must (re)try dm_setup_md_queue independently of
establishing md->type.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:02 +01:00
Mike Snitzer
a5664dad7e dm ioctl: make bio or request based device type immutable
Determine whether a mapped device is bio-based or request-based when
loading its first (inactive) table and don't allow that to be changed
later.

This patch performs different device initialisation in each of the two
cases.  (We don't think it's necessary to add code to support changing
between the two types.)

Allowed md->type transitions:
  DM_TYPE_NONE to DM_TYPE_BIO_BASED
  DM_TYPE_NONE to DM_TYPE_REQUEST_BASED

We now prevent table_load from replacing the inactive table with a
conflicting type of table even after an explicit table_clear.

Introduce 'type_lock' into the struct mapped_device to protect md->type
and to prepare for the next patch that will change the queue
initialization and allocate memory while md->type_lock is held.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

 drivers/md/dm-ioctl.c    |   15 +++++++++++++++
 drivers/md/dm.c          |   37 ++++++++++++++++++++++++++++++-------
 drivers/md/dm.h          |    5 +++++
 include/linux/dm-ioctl.h |    4 ++--
 4 files changed, 52 insertions(+), 9 deletions(-)
2010-08-12 04:14:01 +01:00
Mikulas Patocka
708e929513 dm: skip second flush on bio unsupported error
When processing barriers, skip the second flush if processing the bio
failed with -EOPNOTSUPP.  This can happen with discard+barrier requests.
If the device doesn't support discard, there would be two useless
SYNCHRONIZE CACHE commands.  The first dm_flush cannot be so easily
optimized out, so we leave it there.

Previously, -EOPNOTSUPP could be received in dec_pending only with empty
barriers and we ignored that error, assuming the device not supporting
cache flushes has cache always consistent.  With the addition of discard
barriers, this -EOPNOTSUPP can also be generated by discards and we
must record it in md->barrier_error for process_barrier.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:14:00 +01:00
Tomohiro Kusumi
87c961cb74 dm snapshot: persistent use define for disk header chunk size
This patch fixes hard-coded value for the size of a chunk that includes
disk header for persistent snapshot. It should be changed to existing
macro NUM_SNAPSHOT_HDR_CHUNKS instead of using hard-coded value 1.

Signed-off-by: Tomohiro Kusumi <kusumi.tomohiro@jp.fujitsu.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:59 +01:00
Julia Lawall
a9c88f2ebc dm crypt: use kstrdup
Use kstrdup when the goal of an allocation is copy a string into the
allocated region.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression from,to;
expression flag,E1,E2;
statement S;
@@

-  to = kmalloc(strlen(from) + 1,flag);
+  to = kstrdup(from, flag);
   ... when != \(from = E1 \| to = E1 \)
   if (to==NULL || ...) S
   ... when != \(from = E2 \| to = E2 \)
-  strcpy(to, from);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:58 +01:00
Arnd Bergmann
402ab352c2 dm ioctl: use nonseekable_open
The dm control device does not implement read/write, so it has no use for
seeking.  Using no_llseek prevents falling back to default_llseek, which
requires the BKL.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:57 +01:00
Kiyoshi Ueda
3f77316de0 dm: separate device deletion from dm_put
This patch separates the device deletion code from dm_put()
to make sure the deletion happens in the process context.

By this patch, device deletion always occurs in an ioctl (process)
context and dm_put() can be called in interrupt context.
As a result, the request-based dm's bad dm_put() usage pointed out
by Mikulas below disappears.
    http://marc.info/?l=dm-devel&m=126699981019735&w=2

Without this patch, I confirmed there is a case to crash the system:
    dm_put() => dm_table_destroy() => vfree() => BUG_ON(in_interrupt())

Some more backgrounds and details:
In request-based dm, a device opener can remove a mapped_device
while the last request is still completing, because bios in the last
request complete first and then the device opener can close and remove
the mapped_device before the last request completes:
  CPU0                                          CPU1
  =================================================================
  <<INTERRUPT>>
  blk_end_request_all(clone_rq)
    blk_update_request(clone_rq)
      bio_endio(clone_bio) == end_clone_bio
        blk_update_request(orig_rq)
          bio_endio(orig_bio)
                                                <<I/O completed>>
                                                dm_blk_close()
                                                dev_remove()
                                                  dm_put(md)
                                                    <<Free md>>
   blk_finish_request(clone_rq)
     ....
     dm_end_request(clone_rq)
       free_rq_clone(clone_rq)
       blk_end_request_all(orig_rq)
       rq_completed(md)

So request-based dm used dm_get()/dm_put() to hold md for each I/O
until its request completion handling is fully done.
However, the final dm_put() can call the device deletion code which
must not be run in interrupt context and may cause kernel panic.

To solve the problem, this patch moves the device deletion code,
dm_destroy(), to predetermined places that is actually deleting
the mapped_device in ioctl (process) context, and changes dm_put()
just to decrement the reference count of the mapped_device.
By this change, dm_put() can be used in any context and the symmetric
model below is introduced:
    dm_create():  create a mapped_device
    dm_destroy(): destroy a mapped_device
    dm_get():     increment the reference count of a mapped_device
    dm_put():     decrement the reference count of a mapped_device

dm_destroy() waits for all references of the mapped_device to disappear,
then deletes the mapped_device.

dm_destroy() uses active waiting with msleep(1), since deleting
the mapped_device isn't performance-critical task.
And since at this point, nobody opens the mapped_device and no new
reference will be taken, the pending counts are just for racing
completing activity and will eventually decrease to zero.

For the unlikely case of the forced module unload, dm_destroy_immediate(),
which doesn't wait and forcibly deletes the mapped_device, is also
introduced and used in dm_hash_remove_all().  Otherwise, "rmmod -f"
may be stuck and never return.
And now, because the mapped_device is deleted at this point, subsequent
accesses to the mapped_device may cause NULL pointer references.

Cc: stable@kernel.org
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:56 +01:00
Kiyoshi Ueda
98f332855e dm ioctl: release _hash_lock between devices in remove_all
This patch changes dm_hash_remove_all() to release _hash_lock when
removing a device.  After removing the device, dm_hash_remove_all()
takes _hash_lock and searches the hash from scratch again.

This patch is a preparation for the next patch, which changes device
deletion code to wait for md reference to be 0.  Without this patch,
the wait in the next patch may cause AB-BA deadlock:
  CPU0                                CPU1
  -----------------------------------------------------------------------
  dm_hash_remove_all()
    down_write(_hash_lock)
                                      table_status()
                                        md = find_device()
                                               dm_get(md)
                                                 <increment md->holders>
                                        dm_get_live_or_inactive_table()
                                          dm_get_inactive_table()
                                            down_write(_hash_lock)
    <in the md deletion code>
      <wait for md->holders to be 0>

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:55 +01:00
Kiyoshi Ueda
abdc568b05 dm: prevent access to md being deleted
This patch prevents access to mapped_device which is being deleted.

Currently, even after a mapped_device has been removed from the hash,
it could be accessed through idr_find() using minor number.
That could cause a race and NULL pointer reference below:
  CPU0                          CPU1
  ------------------------------------------------------------------
  dev_remove(param)
    down_write(_hash_lock)
    dm_lock_for_deletion(md)
      spin_lock(_minor_lock)
      set_bit(DMF_DELETING)
      spin_unlock(_minor_lock)
    __hash_remove(hc)
    up_write(_hash_lock)
                                dev_status(param)
                                  md = find_device(param)
                                         down_read(_hash_lock)
                                         __find_device_hash_cell(param)
                                           dm_get_md(param->dev)
                                             md = dm_find_md(dev)
                                                    spin_lock(_minor_lock)
                                                    md = idr_find(MINOR(dev))
                                                    spin_unlock(_minor_lock)
    dm_put(md)
      free_dev(md)
                                             dm_get(md)
                                         up_read(_hash_lock)
                                  __dev_status(md, param)
                                  dm_put(md)

This patch fixes such problems.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:54 +01:00
Peter Rajnoha
856a6f1dbd dm ioctl: return uevent flag after rename
All the dm ioctls that generate uevents set the DM_UEVENT_GENERATED flag so
that userspace knows whether or not to wait for a uevent to be processed
before continuing,

The dm rename ioctl sets this flag but was not structured to return it
to userspace.  This patch restructures the rename ioctl processing to
behave like the other ioctls that return data and so fix this.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:53 +01:00
Alasdair G Kergon
094ea9a071 dm ioctl: make __dev_status void
__dev_status() cannot fail so make it void and simplify callers.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:52 +01:00
Peter Rajnoha
6be5449401 dm ioctl: remove __dev_status from geometry and target message
Remove useless __dev_status call while processing an ioctl that sets up
device geometry and target message.  The data is not returned to
userspace so there is no point collecting it and in the case of
target_message it is collected before processing the message so if it
did return it might be stale.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:52 +01:00
Mikulas Patocka
c241104506 dm snapshot: test chunk size against both origin and snapshot
Validate chunk size against both origin and snapshot sector size

Don't allow chunk size smaller than either origin or snapshot logical
sector size. Reading or writing data not aligned to sector size is not
allowed and causes immediate errors.

This requires us to open the origin before initialising the
exception store and to export dm_snap_origin.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:51 +01:00
Mikulas Patocka
1e5554c842 dm snapshot: iterate origin and cow devices
Iterate both origin and snapshot devices

iterate_devices method should call the callback for all the devices where
the bio may be remapped. Thus, snapshot_iterate_devices should call the callback
for both snapshot and origin underlying devices because it remaps some bios
to the snapshot and some to the origin.

snapshot_iterate_devices called the callback only for the origin device.
This led to badly calculated device limits if snapshot and origin were placed
on different types of disks.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:50 +01:00
Alasdair G Kergon
6bbf79a140 dm mpath: fix NULL pointer dereference when path parameters missing
multipath_ctr() forgets to return an error after detecting
missing path parameters.  Fix this.

Signed-off-by: Patrick LoPresti <lopresti@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12 04:13:49 +01:00
Linus Torvalds
3d30701b58 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (24 commits)
  md: clean up do_md_stop
  md: fix another deadlock with removing sysfs attributes.
  md: move revalidate_disk() back outside open_mutex
  md/raid10: fix deadlock with unaligned read during resync
  md/bitmap:  separate out loading a bitmap from initialising the structures.
  md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.
  md/bitmap: optimise scanning of empty bitmaps.
  md/bitmap: clean up plugging calls.
  md/bitmap: reduce dependence on sysfs.
  md/bitmap: white space clean up and similar.
  md/raid5: export raid5 unplugging interface.
  md/plug: optionally use plugger to unplug an array during resync/recovery.
  md/raid5: add simple plugging infrastructure.
  md/raid5: export is_congested test
  raid5: Don't set read-ahead when there is no queue
  md: add support for raising dm events.
  md: export various start/stop interfaces
  md: split out md_rdev_init
  md: be more careful setting MD_CHANGE_CLEAN
  md/raid5: ensure we create a unique name for kmem_cache when mddev has no gendisk
  ...
2010-08-10 15:38:19 -07:00
NeilBrown
fd8aa2c181 Merge git://git.infradead.org/users/dwmw2/libraid-2.6 into for-linus 2010-08-10 10:02:33 +10:00
David Woodhouse
2144381da4 Merge branch 'async' of macbook:git/btrfs-unstable
Conflicts:
	drivers/md/Makefile
	lib/raid6/unroll.pl
2010-08-09 10:36:44 +01:00
NeilBrown
6e17b02764 md: clean up do_md_stop
There is only one error exit from do_md_stop, so make that more
explicit and discard the 'err' variable.
Also drop the 'revalidate' variable by moving the unlock calls around.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-08 21:22:45 +10:00
NeilBrown
bb4f1e9d0e md: fix another deadlock with removing sysfs attributes.
Move the deletion of sysfs attributes from reconfig_mutex to
open_mutex didn't really help as a process can try to take
open_mutex while holding reconfig_mutex, so the same deadlock can
happen, just requiring one more process to be involved in the chain.

I looks like I cannot easily use locking to wait for the sysfs
deletion to complete, so don't.

The only things that we cannot do while the deletions are still
pending is other things which can change the sysfs namespace: run,
takeover, stop.  Each of these can fail with -EBUSY.
So set a flag while doing a sysfs deletion, and fail run, takeover,
stop if that flag is set.

This is suitable for 2.6.35.x

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-08 21:21:27 +10:00
Dan Williams
147e0b6a63 md: move revalidate_disk() back outside open_mutex
Commit b821eaa5 "md: remove ->changed and related code" moved
revalidate_disk() under open_mutex, and lockdep noticed.

[ INFO: possible circular locking dependency detected ]
2.6.32-mdadm-locking #1
-------------------------------------------------------
mdadm/3640 is trying to acquire lock:
 (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff811acecb>] revalidate_disk+0x5b/0x90

but task is already holding lock:
 (&mddev->open_mutex){+.+...}, at: [<ffffffffa055e07a>] do_md_stop+0x4a/0x4d0 [md_mod]

which lock already depends on the new lock.

It is suitable for 2.6.35.x

Cc: <stable@kernel.org>
Reported-by: Przemyslaw Czarnowski <przemyslaw.hawrylewicz.czarnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-08 21:20:17 +10:00
Arnd Bergmann
6e9624b8ca block: push down BKL into .open and .release
The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.

This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.

The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.

Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:25:34 +02:00
FUJITA Tomonori
00fff26539 block: remove q->prepare_flush_fn completely
This removes q->prepare_flush_fn completely (changes the
blk_queue_ordered API).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:24:15 +02:00
FUJITA Tomonori
144d6ed551 dm: stop using q->prepare_flush_fn
use REQ_FLUSH flag instead.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Alasdair G Kergon <agk@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:24:14 +02:00
Christoph Hellwig
7b6d91daee block: unify flags for struct bio and struct request
Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver.  There were two flags in the bio that were
missing in the requests:  BIO_RW_UNPLUG and BIO_RW_AHEAD.  Also I've
renamed two request flags that had a superflous RW in them.

Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:20:39 +02:00
Christoph Hellwig
33659ebbae block: remove wrappers for request type/flags
Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests.  This allows much easier grepping for different request
types instead of unwinding through macros.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:17:56 +02:00
NeilBrown
51e9ac7703 md/raid10: fix deadlock with unaligned read during resync
If the 'bio_split' path in raid10-read is used while
resync/recovery is happening it is possible to deadlock.
Fix this be elevating ->nr_waiting for the duration of both
parts of the split request.

This fixes a bug that has been present since 2.6.22
but has only started manifesting recently for unknown reasons.
It is suitable for and -stable since then.

Reported-by:  Justin Bronder <jsbronder@gentoo.org>
Tested-by:  Justin Bronder <jsbronder@gentoo.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-08-07 21:17:00 +10:00
NeilBrown
69e51b449d md/bitmap: separate out loading a bitmap from initialising the structures.
dm makes this distinction between ->ctr and ->resume, so we need to
too.

Also get the new bitmap_load to clear out the bitmap first, as this is
most consistent with the dm suspend/resume approach

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:34 +10:00
NeilBrown
e384e58549 md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.
This allows md/raid5 to fully work as a dm target.

Normally md uses a 'filemap' which contains a list of pages of bits
each of which may be written separately.
dm-log uses and all-or-nothing approach to writing the log, so
when using a dm-log, ->filemap is NULL and the flags normally stored
in filemap_attr are stored in ->logattrs instead.



Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:34 +10:00
NeilBrown
ef42567335 md/bitmap: optimise scanning of empty bitmaps.
A bitmap is stored as one page per 2048 bits.
If none of the bits are set, the page is not allocated.

When bitmap_get_counter finds that a page isn't allocate,
it just reports that one bit work of space isn't flagged,
rather than reporting that 2048 bits worth of space are
unflagged.
This can cause searches for flagged bits (e.g. bitmap_close_sync)
to do more work than is really necessary.

So change bitmap_get_counter (when creating) to report a number of
blocks that more accurately reports the range of the device for which
no counter currently exists.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:32 +10:00
NeilBrown
b63d7c2e29 md/bitmap: clean up plugging calls.
1/ use md_unplug in bitmap.c as we will soon be using bitmaps under
  arrays with no queue attached.

2/ Don't bother plugging the queue when we set a bit in the bitmap.
   The reason for this was to encourage as many bits as possible to
   get set before we unplug and write stuff out.
   However every personality already plugs the queue after
   bitmap_startwrite either directly (raid1/raid10) or be setting
   STRIPE_BIT_DELAY which causes the queue to be plugged later
   (raid5).

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:32 +10:00
NeilBrown
5ff5afffe6 md/bitmap: reduce dependence on sysfs.
For dm-raid45 we will want to use bitmaps in dm-targets which don't
have entries in sysfs, so cope with the mddev not living in sysfs.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:21:31 +10:00
NeilBrown
ac2f40be46 md/bitmap: white space clean up and similar.
Fixes some whitespace problems
Fixed some checkpatch.pl complaints.
Replaced kmalloc ... memset(0), with kzalloc
Fixed an unlikely memory leak on an error path.
Reformatted a number of 'if/else' sets, sometimes
replacing goto with an else clause.
Removed some old comments and commented-out code.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 13:07:22 +10:00
NeilBrown
9f7c222001 md/raid5: export raid5 unplugging interface.
Also remove remaining accesses to ->queue and ->gendisk when ->queue
is NULL (As it is in a DM target).

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:53:10 +10:00
NeilBrown
252ac5221a md/plug: optionally use plugger to unplug an array during resync/recovery.
If an array doesn't have a 'queue' then md_do_sync cannot
unplug it.
In that case it will have a 'plugger', so make that available
to the mddev, and use it to unplug the array if needed.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:53:08 +10:00
NeilBrown
2ac8740151 md/raid5: add simple plugging infrastructure.
md/raid5 uses the plugging infrastructure provided by the block layer
and 'struct request_queue'.  However when we plug raid5 under dm there
is no request queue so we cannot use that.

So create a similar infrastructure that is much lighter weight and use
it for raid5.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:53:08 +10:00
NeilBrown
11d8a6e371 md/raid5: export is_congested test
the dm module will need this for dm-raid45.

Also only access ->queue->backing_dev_info->congested_fn
if ->queue actually exists.  It won't in a dm target.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:29 +10:00
NeilBrown
4a5add4995 raid5: Don't set read-ahead when there is no queue
dm-raid456 does not provide a 'queue' for raid5 to use,
so we must make raid5 stop depending on the queue.

First: read_ahead
dm handles read-ahead adjustment fully in userspace, so
simply don't do any readahead adjustments if there is
no queue.

Also re-arrange code slightly so all the accesses to ->queue are
together.

Finally, move the blk_queue_merge_bvec function into the 'if' as
the ->split_io setting in dm-raid456 has the same effect.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown
768a418db1 md: add support for raising dm events.
dm uses scheduled work to raise events to user-space.
So allow md device to have work_structs and schedule them on an error.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown
390ee602a1 md: export various start/stop interfaces
export entry points for starting and stopping md arrays.
This will be used by a module to make md/raid5 work under
dm.
Also stop calling md_stop_writes from md_stop, as that won't
work well with dm - it will want to call the two separately.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown
e8bb9a839a md: split out md_rdev_init
This functionality will be needed separately in a subsequent patch, so
split it into it's own exported function.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown
676e42d896 md: be more careful setting MD_CHANGE_CLEAN
When MD_CHANGE_CLEAN is set we might block in md_write_start.
So we should only set it when fairly sure that something will clear
it.

There are two places where it is set so as to encourage a metadata
update to record the progress of resync/recovery.  This should only
be done if the internal metadata update mechanisms are in use, which
can be tested by by inspecting '->persistent'.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:27 +10:00
NeilBrown
f4be6b43f1 md/raid5: ensure we create a unique name for kmem_cache when mddev has no gendisk
We will shortly allow md devices with no gendisk (they are attached to
a dm-target instead).  That will cause mdname() to return 'mdX'.
There is one place where mdname really needs to be unique: when
creating the name for a slab cache.
So in that case, if there is no gendisk, you the address of the mddev
formatted in HEX to provide a unique name.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-26 12:52:26 +10:00
NeilBrown
c41d4ac40d md/raid5: factor out code for changing size of stripe cache.
Separate the actual 'change' code from the sysfs interface
so that it can eventually be called internally.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-21 13:28:15 +10:00
NeilBrown
00bcb4ac7e md: reduce dependence on sysfs.
We will want md devices to live as dm targets where sysfs is not
visible.  So allow md to not connect to sysfs.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-07-21 13:27:53 +10:00
NeilBrown
3424bf6a77 md/raid5: don't include 'spare' drives when reshaping to fewer devices.
There are few situations where it would make any sense to add a spare
when reducing the number of devices in an array, but it is
conceivable:  A 6 drive RAID6 with two missing devices could be
reshaped to a 5 drive RAID6, and a spare could become available
just in time for the reshape, but not early enough to have been
recovered first.  'freezing' recovery can make this easy to
do without any races.

However doing such a thing is a bad idea.  md will not record the
partially-recovered state of the 'spare' and when the reshape
finished it will think that the spare is still spare.
Easiest way to avoid this confusion is to simply disallow it.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:36:04 +10:00
NeilBrown
2f11588249 md/raid5: add a missing 'continue' in a loop.
As the comment says, the tail of this loop only applies to devices
that are not fully in sync, so if In_sync was set, we should avoid
the rest of the loop.

This bug will hardly ever cause an actual problem.  The worst it
can do is allow an array to be assembled that is dirty and degraded,
which is not generally a good idea (without warning the sysadmin
first).

This will only happen if the array is RAID4 or a RAID5/6 in an
intermediate state during a reshape and so has one drive that is
all 'parity' - no data - while some other device has failed.

This is certainly possible, but not at all common.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:35:49 +10:00
NeilBrown
415e72d034 md/raid5: Allow recovered part of partially recovered devices to be in-sync
During a recovery of reshape the early part of some devices might be
in-sync while the later parts are not.
We we know we are looking at an early part it is good to treat that
part as in-sync for stripe calculations.

This is particularly important for a reshape which suffers device
failure.  Treating the data as in-sync can mean the difference between
data-safety and data-loss.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:35:39 +10:00
NeilBrown
674806d62f md/raid5: More careful check for "has array failed".
When we are reshaping an array, the device failure combinations
that cause us to decide that the array as failed are more subtle.

In particular, any 'spare' will be fully in-sync in the section
of the array that has already been reshaped, thus failures that
affect only that section are less critical.

So encode this subtlety in a new function and call it as appropriate.

The case that showed this problem was a 4 drive RAID5 to 8 drive RAID6
conversion where the last two devices failed.
This resulted in:

  good good good good incomplete good good failed failed

while converting a 5-drive RAID6 to 8 drive RAID5
The incomplete device causes the whole array to look bad,
bad as it was actually good for the section that had been
converted to 8-drives, all the data was actually safe.

Reported-by: Terry Morris <tbmorris@tbmorris.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:35:27 +10:00
NeilBrown
70fffd0bfa md: Don't update ->recovery_offset when reshaping an array to fewer devices.
When an array is reshaped to have fewer devices, the reshape proceeds
from the end of the devices to the beginning.

If a device happens to be non-In_sync (which is possible but rare)
we would normally update the ->recovery_offset as the reshape
progresses. However that would be wrong as the recover_offset records
that the early part of the device is in_sync, while in fact it would
only be the later part that is in_sync, and in any case the offset
number would be measured from the wrong end of the device.

Relatedly, if after a reshape a spare is discovered to not be
recoverred all the way to the end, not allow spare_active
to incorporate it in the array.

This becomes relevant in the following sample scenario:

A 4 drive RAID5 is converted to a 6 drive RAID6 in a combined
operation.
The RAID5->RAID6 conversion will cause a 5 drive to be included as a
spare, then the 5drive -> 6drive reshape will effectively rebuild that
spare as it progresses.  The 6th drive is treated as in_sync the whole
time as there is never any case that we might consider reading from
it, but must not because there is no valid data.

If we interrupt this reshape part-way through and reverse it to return
to a 5-drive RAID6 (or event a 4-drive RAID5), we don't want to update
the recovery_offset - as that would be wrong - and we don't want to
include that spare as active in the 5-drive RAID6 when the reversed
reshape completed and it will be mostly out-of-sync still.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:35:18 +10:00
NeilBrown
e4e11e385d md/raid5: avoid oops when number of devices is reduced then increased.
The entries in the stripe_cache maintained by raid5 are enlarged
when we increased the number of devices in the array, but not
shrunk when we reduce the number of devices.
So if entries are added after reducing the number of devices, we
much ensure to initialise the whole entry, not just the part that
is currently relevant.  Otherwise if we enlarge the array again,
we will reference uninitialised values.

As grow_buffers/shrink_buffer now want to use a count that is stored
explicity in the raid_conf, they should get it from there rather than
being passed it as a parameter.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:35:02 +10:00
Maciej Trela
049d6c1ef9 md: enable raid4->raid0 takeover
Only level 5 with layout=PARITY_N can be taken over to raid0 now.
Lets allow level 4 either.

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:34:57 +10:00
Maciej Trela
001048a318 md: clear layout after ->raid0 takeover
After takeover from raid5/10 -> raid0 mddev->layout is not cleared.

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:34:45 +10:00
Maciej Trela
f73ea87375 md: fix raid10 takeover: use new_layout for setup_conf
Use mddev->new_layout in setup_conf.
Also use new_chunk, and don't set ->degraded in takeover().  That
gets set in run()

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:33:51 +10:00
NeilBrown
e93f68a1fc md: fix handling of array level takeover that re-arranges devices.
Most array level changes leave the list of devices largely unchanged,
possibly causing one at the end to become redundant.
However conversions between RAID0 and RAID10 need to renumber
all devices (except 0).

This renumbering is currently being done in the ->run method when the
new personality takes over.  However this is too late as the common
code in md.c might already have invalidated some of the devices if
they had a ->raid_disk number that appeared to high.

Moving it into the ->takeover method is too early as the array is
still active at that time and wrong ->raid_disk numbers could cause
confusion.

So add a ->new_raid_disk field to mdk_rdev_s and use it to communicate
the new raid_disk number.
Now the common code knows exactly which devices need to be renumbered,
and which can be invalidated, and can do it all at a convenient time
when the array is suspend.
It can also update some symlinks in sysfs which previously were not be
updated correctly.

Reported-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:33:24 +10:00
Prasanna S. Panchamukhi
0544a21db0 md: raid10: Fix null pointer dereference in fix_read_error()
Such NULL pointer dereference can occur when the driver was fixing the
read errors/bad blocks and the disk was physically removed
causing a system crash. This patch check if the
rcu_dereference() returns valid rdev before accessing it in fix_read_error().

Cc: stable@kernel.org
Signed-off-by: Prasanna S. Panchamukhi <prasanna.panchamukhi@riverbed.com>
Signed-off-by: Rob Becker <rbecker@riverbed.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:31:03 +10:00
NeilBrown
f3b99be19d Restore partition detection of newly created md arrays.
Commit  b821eaa572 broke partition
detection for md arrays.

The logic was almost right.  However if revalidate_disk is called
when the device is not yet open, bdev->bd_disk won't be set, so the
flush_disk() Call will not set bd_invalidated.

So when md_open is called we still need to ensure that
->bd_invalidated gets set.  This is easily done with a call to
check_disk_size_change in the place where the offending commit removed
check_disk_change.  At the important times, the size will have changed
from 0 to non-zero, so check_disk_size_change will set bd_invalidated.

Tested-by: Duncan <1i5t5.duncan@cox.net>
Reported-by: Duncan <1i5t5.duncan@cox.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24 13:31:03 +10:00
Akinobu Mita
55af6bb509 md: convert cpu notifier to return encapsulate errno value
By the previous modification, the cpu notifier can return encapsulate
errno value.  This converts the cpu notifiers for raid5.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:48 -07:00
Linus Torvalds
e8bebe2f71 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (69 commits)
  fix handling of offsets in cris eeprom.c, get rid of fake on-stack files
  get rid of home-grown mutex in cris eeprom.c
  switch ecryptfs_write() to struct inode *, kill on-stack fake files
  switch ecryptfs_get_locked_page() to struct inode *
  simplify access to ecryptfs inodes in ->readpage() and friends
  AFS: Don't put struct file on the stack
  Ban ecryptfs over ecryptfs
  logfs: replace inode uid,gid,mode initialization with helper function
  ufs: replace inode uid,gid,mode initialization with helper function
  udf: replace inode uid,gid,mode init with helper
  ubifs: replace inode uid,gid,mode initialization with helper function
  sysv: replace inode uid,gid,mode initialization with helper function
  reiserfs: replace inode uid,gid,mode initialization with helper function
  ramfs: replace inode uid,gid,mode initialization with helper function
  omfs: replace inode uid,gid,mode initialization with helper function
  bfs: replace inode uid,gid,mode initialization with helper function
  ocfs2: replace inode uid,gid,mode initialization with helper function
  nilfs2: replace inode uid,gid,mode initialization with helper function
  minix: replace inode uid,gid,mode init with helper
  ext4: replace inode uid,gid,mode init with helper
  ...

Trivial conflict in fs/fs-writeback.c (mark bitfields unsigned)
2010-05-21 19:37:45 -07:00
NeilBrown
19fdb9eefb Merge commit '3ff195b011d7decf501a4d55aeed312731094796' into for-linus
Conflicts:
	drivers/md/md.c

- Resolved conflict in md_update_sb
- Added extra 'NULL' arg to new instance of sysfs_get_dirent.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-22 08:31:36 +10:00
Christoph Hellwig
8018ab0574 sanitize vfs_fsync calling conventions
Now that the last user passing a NULL file pointer is gone we can remove
the redundant dentry argument and associated hacks inside vfs_fsynmc_range.

The next step will be removig the dentry argument from ->fsync, but given
the luck with the last round of method prototype changes I'd rather
defer this until after the main merge window.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:21 -04:00
Eric W. Biederman
3ff195b011 sysfs: Implement sysfs tagged directory support.
The problem.  When implementing a network namespace I need to be able
to have multiple network devices with the same name.  Currently this
is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and
potentially a few other directories of the form /sys/ ... /net/*.

What this patch does is to add an additional tag field to the
sysfs dirent structure.  For directories that should show different
contents depending on the context such as /sys/class/net/, and
/sys/devices/virtual/net/ this tag field is used to specify the
context in which those directories should be visible.  Effectively
this is the same as creating multiple distinct directories with
the same name but internally to sysfs the result is nicer.

I am calling the concept of a single directory that looks like multiple
directories all at the same path in the filesystem tagged directories.

For the networking namespace the set of directories whose contents I need
to filter with tags can depend on the presence or absence of hotplug
hardware or which modules are currently loaded.  Which means I need
a simple race free way to setup those directories as tagged.

To achieve a reace free design all tagged directories are created
and managed by sysfs itself.

Users of this interface:
- define a type in the sysfs_tag_type enumeration.
- call sysfs_register_ns_types with the type and it's operations
- sysfs_exit_ns when an individual tag is no longer valid

- Implement mount_ns() which returns the ns of the calling process
  so we can attach it to a sysfs superblock.
- Implement ktype.namespace() which returns the ns of a syfs kobject.

Everything else is left up to sysfs and the driver layer.

For the network namespace mount_ns and namespace() are essentially
one line functions, and look to remain that.

Tags are currently represented a const void * pointers as that is
both generic, prevides enough information for equality comparisons,
and is trivial to create for current users, as it is just the
existing namespace pointer.

The work needed in sysfs is more extensive.  At each directory
or symlink creating I need to check if the directory it is being
created in is a tagged directory and if so generate the appropriate
tag to place on the sysfs_dirent.  Likewise at each symlink or
directory removal I need to check if the sysfs directory it is
being removed from is a tagged directory and if so figure out
which tag goes along with the name I am deleting.

Currently only directories which hold kobjects, and
symlinks are supported.  There is not enough information
in the current file attribute interfaces to give us anything
to discriminate on which makes it useless, and there are
no potential users which makes it an uninteresting problem
to solve.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21 09:37:31 -07:00
NeilBrown
be6800a73a md: don't insist on valid event count for spare devices.
Devices which know that they are spares do not really need to have
an event count that matches the rest of the array, so there are no
data-in-sync issues. It is enough that the uuid matches.
So remove the requirement that the event count is up-to-date.

We currently still write out and event count on spares, but this
allows us in a year or 3 to stop doing that completely.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:28:01 +10:00
NeilBrown
a8707c08f4 md: simplify updating of event count to sometimes avoid updating spares.
When updating the event count for a simple clean <-> dirty transition,
we try to avoid updating the spares so they can safely spin-down.
As the event_counts across an array must be +/- 1, this means
decrementing the event_count on a dirty->clean transition.
This is not always safe and we have to avoid the unsafe time.
We current do this with a misguided idea about it being safe or
not depending on whether the event_count is odd or even.  This
approach only works reliably in a few common instances, but easily
falls down.

So instead, simply keep internal state concerning whether it is safe
or not, and always assume it is not safe when an array is first
assembled.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:28:01 +10:00
Gabriele A. Trombetti
7b0bb5368a md/raid6: Fix raid-6 read-error correction in degraded state
Fix: Raid-6 was not trying to correct a read-error when in
singly-degraded state and was instead dropping one more device, going to
doubly-degraded state. This patch fixes this behaviour.

Tested-by: Janos Haar <janos.haar@netcenter.hu>
Signed-off-by: Gabriele A. Trombetti <g.trombetti.lkrnl1213@logicschema.com>
Reported-by: Janos Haar <janos.haar@netcenter.hu>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-05-18 15:28:00 +10:00
NeilBrown
75a73a29e5 md: restore ability of spare drives to spin down.
Some time ago we stopped the clean/active metadata updates
from being written to a 'spare' device in most cases so that
it could spin down and say spun down.  Device failure/removal
etc are still recorded on spares.

However commit 51d5668cb2 broke this 50% of the time,
depending on whether the event count is even or odd.
The change log entry said:

   This means that the alignment between 'odd/even' and
    'clean/dirty' might take a little longer to attain,

how ever the code makes no attempt to create that alignment, so it
could take arbitrarily long.

So when we find that clean/dirty is not aligned with odd/even,
force a second metadata-update immediately.  There are already cases
where a second metadata-update is needed immediately (e.g. when a
device fails during the metadata update).  We just piggy-back on that.

Reported-by: Joe Bryant <tenminjoe@yahoo.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-05-18 15:28:00 +10:00
NeilBrown
af3a2cd6b8 md: Fix read balancing in RAID1 and RAID10 on drives > 2TB
read_balance uses a "unsigned long" for a sector number which
will get truncated beyond 2TB.
This will cause read-balancing to be non-optimal, and can cause
data to be read from the 'wrong' branch during a resync.  This has a
very small chance of returning wrong data.

Reported-by: Jordan Russell <jr-list-2010@quo.to>
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:28:00 +10:00
NeilBrown
2dc40f8094 md/linear: standardise all printk messages
md/linear:mdname:

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:59 +10:00
NeilBrown
b5a20961f3 md/raid0: tidy up printk messages.
All messages now start
   md/raid0:md-device-name:

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:59 +10:00
NeilBrown
128595ed6f md/raid10: tidy up printk messages.
All raid10 printk messages now start
   md/raid10:md-device-name:

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:59 +10:00
NeilBrown
9dd1e2faf7 md/raid1: improve printk messages
Make sure the array name is included in a uniform way in all printk
messages.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:59 +10:00
NeilBrown
0c55e02259 md/raid5: improve consistency of error messages.
Many 'printk' messages from the raid456 module mention 'raid5' even
though it may be a 'raid6' or even 'raid4' array.  This can cause
confusion.
Also the actual array name is not always reported and when it is
it is not reported consistently.

So change all the messages to start:
    md/raid:%s:
where '%s' becomes e.g. md3 to identify the particular array.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:58 +10:00
NeilBrown
08fb730ca3 md: remove EXPERIMENTAL designation from RAID10
RAID10 has been available for quite a while now and is quite well
tested, so we can remove the EXPERIMENTAL designation.

Reported-by: Eric MSP Veith <eveith@wwweb-library.net>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:58 +10:00
Dan Williams
f2859af671 md: allow integers to be passed to md/level
e.g. allow md to interpret 'echo 4 > md/level' as a request for raid4.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-18 15:27:58 +10:00
Dan Williams
bb7f8d2217 md: notify mdstat waiters of level change
Level modifications change the output of mdstat.  The mdmon manager
thread is interested in these events for external metadata management.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-18 15:27:57 +10:00
Dan Williams
f1b29bcae1 md/raid4: permit raid0 takeover
For consistency allow raid4 to takeover raid0 in addition to raid5 (with a
raid4 layout).

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-18 15:27:57 +10:00
NeilBrown
e555190d82 md/raid1: delay reads that could overtake behind-writes.
When a raid1 array is configured to support write-behind
on some devices, it normally only reads from other devices.
If all devices are write-behind (because the rest have failed)
it is possible for a read request to be serviced before a
behind-write request, which would appear as data corruption.

So when forced to read from a WriteMostly device, wait for any
write-behind to complete, and don't start any more behind-writes.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:57 +10:00
NeilBrown
d754c5ae1f md/raid1: fix confusing 'redirect sector' message.
This message seems to suggest the named device is the one on which a
read failed, however it is actually the device that the read will be
redirected to.
So make the message a little clearer.

Reported-by: Tim Burgess <ozburgess@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:56 +10:00
NeilBrown
9e35b99c7e md: don't unregister the thread in mddev_suspend
This is
 - unnecessary because mddev_suspend is always followed by a call to
   ->stop, and each ->stop unregisters the thread, and
 - a problem as it makes it awkwards to suspend and then resume a
   device as we will want later.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:56 +10:00
NeilBrown
fafd7fb052 md: factor out init code for an mddev
This is a simple factorisation that makes mddev_find easier to read.


Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:55 +10:00
NeilBrown
21a52c6d05 md: pass mddev to make_request functions rather than request_queue
We used to pass the personality make_request function direct
to the block layer so the first argument had to be a queue.
But now we have the intermediary md_make_request so it makes
at lot more sense to pass a struct mddev_s.
It makes it possible to have an mddev without its own queue too.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:55 +10:00
NeilBrown
cca9cf90c5 md: call md_stop_writes from md_stop
This moves the call to the other side of set_readonly, but that should
not be an issue.
This encapsulates in 'md_stop' all of the functionality for internally
stopping the array, leaving all the interactions with externalities
(sysfs, request_queue, gendisk) in do_md_stop.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:54 +10:00
NeilBrown
a4bd82d0d0 md: split md_set_readonly out of do_md_stop
Using do_md_stop to set an array to read-only is a little confusing.
Now most of the common code has been factored out, split
md_set_readonly off in to a separate function.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:54 +10:00
NeilBrown
a047e12540 md: factor md_stop_writes out of do_md_stop.
Further refactoring of do_md_stop.
This one requires some explanation as it takes code from different
places in do_md_stop, so some re-ordering happens.

We only get into this part of do_md_stop if there are no active opens
of the device, so no writes can be happening and the device must have
been flushed.  In md_stop_writes we want to stop any internal sources
of writes - i.e. resync - and flush out the metadata.

The only code that was previously before some of this code is
code to clean up the queue, the mddev, the gendisk, or sysfs, all
of which is probably better after code that makes active changes (i.e.
triggers writes).

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:54 +10:00
NeilBrown
6177b472ab md: start to refactor do_md_stop
do_md_stop is large and clunky, so hard to understand.

This is a first step of refactoring, pulling two simple
sub-functions out.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:53 +10:00
NeilBrown
fe60b01428 md: factor do_md_run to separate accesses to ->gendisk
As part of relaxing the binding between an mddev and gendisk,
we separate do_md_run into two functions.
  md_run does all the work internal to md
  do_md_run calls md_run and makes and changes to gendisk
     that are required.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:53 +10:00
NeilBrown
b821eaa572 md: remove ->changed and related code.
We set ->changed to 1 and call check_disk_change at the end
of md_open so that bd_invalidated would be set and thus
partition rescan would happen appropriately.

Now that we call revalidate_disk directly, which sets bd_invalidates,
that indirection is no longer needed and can be removed.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:53 +10:00
NeilBrown
49ce6cea85 md: don't reference gendisk in getgeo
Using ->array_sectors rather than get_capacity() is more
direct and is a step towards relaxing the tight connection
between mddev and gendisk.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:52 +10:00
NeilBrown
490773268c md: move io accounting out of personalities into md_make_request
While I generally prefer letting personalities do as much as possible,
given that we have a central md_make_request anyway we may as well use
it to simplify code.
Also this centralises knowledge of ->gendisk which will help later.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:52 +10:00
NeilBrown
2b7f22284d md/raid5: small tidyup in raid5_align_endio
Diving through ->queue to find mddev is unnecessarily complex - there
is an easier path to finding mddev, so use that.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:50 +10:00
NeilBrown
a78d38a1a1 md: add support for raid5 to raid4 conversion
This is unlikely to be wanted, but we may as well provide it
for completeness.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:49 +10:00
Maciej Trela
5cac7861b2 md: notify level changes through sysfs.
Level changes can be very significant, so make sure
to notify them via sysfs.

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:49 +10:00
NeilBrown
233fca36bb md: Relax checks on ->max_disks when external metadata handling is used.
When metadata is being managed by user-space, md doesn't know
what the maximum number of devices allowed in an array is
so ->max_disks is 0.  In this case we should allow any (+ve)
number of disks.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:49 +10:00
Maciej Trela
b71031076e md: Correctly handle device removal via sysfs
Writing "none" to "../md/dev-xx/slot" removes that device
from being an active part of the array, but it didn't
set ->raid_disk to -1 to record this fact.


Signed-off-by: Maciej Trela <Maciej.Trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:48 +10:00
Trela, Maciej
dab8b29248 md: Add support for Raid0->Raid10 takeover
Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:48 +10:00
Trela, Maciej
9af204cf72 md: Add support for Raid5->Raid0 and Raid10->Raid0 takeover
Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:48 +10:00
Trela Maciej
54071b3808 md:Add support for Raid0->Raid5 takeover
Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:47 +10:00
NeilBrown
84707f38e7 md: don't use mddev->raid_disks in raid0 or raid10 while array is active.
In a subsequent patch we will make it possible to change
mddev->raid_disks while a RAID0 or RAID10 array is active.  This is
part of the process of reshaping such an array.

This means that we cannot use this value while processes requests
(it is OK to use it during initialisation as we are locked against
changes then).
Both RAID0 and RAID10 have the same value stored in the private data
structure, so use that value instead.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:47 +10:00
NeilBrown
c0cc75f84e md: discard StateChanged device flag.
This was needed when sysfs files could only be 'notified'
from process context.  Now that we have sys_notify_direct,
we can call it directly from an interrupt.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:47 +10:00
H Hartley Sweeten
7b92813c3c drivers/md: Remove unnecessary casts of void *
void pointers do not need to be cast to other pointer types.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:46 +10:00
Paul Clements
696fcd535b md: expose max value of behind writes counter
Keep track of the maximum number of concurrent write-behind requests
for an md array and exposed this number in sysfs at
   md/bitmap/max_backlog_used

Writing any value to this file will clear it.

This allows userspace to be involved in tuning bitmap/backlog.

Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:46 +10:00
NeilBrown
ee8b81b03d md: remove some dead fields from mddev_s
These fields have never been used.
commit 4b6d287f62
added them, but also added identical files to bitmap_super_s,
and only used the latter.

So remove these unused fields.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:45 +10:00
NeilBrown
964147d5c8 md/raid1: fix counting of write targets.
There is a very small race window when writing to a
RAID1 such that if a device is marked faulty at exactly the wrong
time, the write-in-progress will not be sent to the device,
but the bitmap (if present) will be updated to say that
the write was sent.

Then if the device turned out to still be usable as was re-added
to the array, the bitmap-based-resync would skip resyncing that
block, possibly leading to corruption.  This would only be a problem
if no further writes were issued to that area of the device (i.e.
that bitmap chunk).

Suitable for any pending -stable kernel.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18 15:27:13 +10:00
NeilBrown
a64c876fd3 md: manage redundancy group in sysfs when changing level.
Some levels expect the 'redundancy group' to be present,
others don't.
So when we change level of an array we might need to
add or remove this group.

This requires fixing up the current practice of overloading ->private
to indicate (when ->pers == NULL) that something needs to be removed.
So create a new ->to_remove to fill that role.

When changing levels, we may need to add or remove attributes.  When
changing RAID5 -> RAID6, we both add and remove the same thing.  It is
important to catch this and optimise it out as the removal is delayed
until a lock is released, so trying to add immediately would cause
problems.


Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-17 14:45:40 +10:00
NeilBrown
b6eb127d27 md: remove unneeded sysfs files more promptly
When an array is stopped we need to remove some
sysfs files which are dependent on the type of array.

We need to delay that deletion as deleting them while holding
reconfig_mutex can lead to deadlocks.

We currently delay them until the array is completely destroyed.
However it is possible to deactivate and then reactivate the array.
It is also possible to need to remove sysfs files when changing level,
which can potentially happen several times before an array is
destroyed.

So we need to delete these files more promptly: as soon as
reconfig_mutex is dropped.

We need to ensure this happens before do_md_run can restart the array,
so we use open_mutex for some extra locking.  This is not deadlock
prone.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-17 14:40:07 +10:00
NeilBrown
ef2f80ff73 md/linear: avoid possible oops and array stop
Since commit ef286f6fa6
it has been important that each personality clears
->private in the ->stop() function, or sets it to a
attribute group to be removed.
linear.c doesn't.  This can sometimes lead to an oops,
though it doesn't always.

Suitable for 2.6.33-stable and 2.6.34.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-05-17 14:38:18 +10:00
Dan Williams
e221835046 md: set mddev readonly flag on blkdev BLKROSET ioctl
When the user sets the block device to readwrite then the mddev should
follow suit.  Otherwise, the BUG_ON in md_write_start() will be set to
trigger.

The reverse direction, setting mddev->ro to match a set readonly
request, can be ignored because the blkdev level readonly flag precludes
the need to have mddev->ro set correctly.  Nevermind the fact that
setting mddev->ro to 1 may fail if the array is in use.

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-12 08:25:37 +10:00
NeilBrown
1176568de7 md: restore ability of spare drives to spin down.
Some time ago we stopped the clean/active metadata updates
from being written to a 'spare' device in most cases so that
it could spin down and say spun down.  Device failure/removal
etc are still recorded on spares.

However commit 51d5668cb2 broke this 50% of the time,
depending on whether the event count is even or odd.
The change log entry said:

   This means that the alignment between 'odd/even' and
    'clean/dirty' might take a little longer to attain,

how ever the code makes no attempt to create that alignment, so it
could take arbitrarily long.

So when we find that clean/dirty is not aligned with odd/even,
force a second metadata-update immediately.  There are already cases
where a second metadata-update is needed immediately (e.g. when a
device fails during the metadata update).  We just piggy-back on that.

Reported-by: Joe Bryant <tenminjoe@yahoo.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-05-07 21:10:57 +10:00
Gabriele A. Trombetti
87aa63000c md/raid6: Fix raid-6 read-error correction in degraded state
Fix: Raid-6 was not trying to correct a read-error when in
singly-degraded state and was instead dropping one more device, going to
doubly-degraded state. This patch fixes this behaviour.

Tested-by: Janos Haar <janos.haar@netcenter.hu>
Signed-off-by: Gabriele A. Trombetti <g.trombetti.lkrnl1213@logicschema.com>
Reported-by: Janos Haar <janos.haar@netcenter.hu>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-05-07 21:10:35 +10:00
NeilBrown
6e3b96ed61 md/raid5: fix previous patch.
Previous patch changes stripe and chunk_number to sector_t but
mistakenly did not update all of the divisions to use sector_dev().

This patch changes all the those divisions (actually the '%' operator)
to sector_div.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
Tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
2010-04-23 07:08:28 +10:00
NeilBrown
35f2a59119 md/raid5: allow for more than 2^31 chunks.
With many large drives and small chunk sizes it is possible
to create a RAID5 with more than 2^31 chunks.  Make sure this
works.

Reported-by: Brett King <king.br@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-04-20 14:13:34 +10:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Linus Torvalds
31cc1dd344 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  md: deal with merge_bvec_fn in component devices better.
2010-03-18 16:55:24 -07:00
NeilBrown
627a2d3c29 md: deal with merge_bvec_fn in component devices better.
If a component device has a merge_bvec_fn then as we never call it
we must ensure we never need to.  Currently this is done by setting
max_sector to 1 PAGE, however this does not stop a bio being created
with several sub-page iovecs that would violate the merge_bvec_fn.

So instead set max_segments to 1 and set the segment boundary to the
same as a page boundary to ensure there is only ever one single-page
segment of IO requested at a time.

This can particularly be an issue when 'xen' is used as it is
known to submit multiple small buffers in a single bio.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2010-03-16 17:04:24 +11:00
Emese Revfy
52cf25d0ab Driver core: Constify struct sysfs_ops in struct kobj_type
Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:49 -08:00
Takahiro Yasui
f070304094 dm raid1: fix deadlock when suspending failed device
To prevent deadlock, bios in the hold list should be flushed before
dm_rh_stop_recovery() is called in mirror_suspend().

The recovery can't start because there are pending bios and therefore
dm_rh_stop_recovery deadlocks.

When there are pending bios in the hold list, the recovery waits for
the completion of the bios after recovery_count is acquired.
The recovery_count is released when the recovery finished, however,
the bios in the hold list are processed after dm_rh_stop_recovery() in
mirror_presuspend(). dm_rh_stop_recovery() also acquires recovery_count,
then deadlock occurs.

Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
2010-03-06 02:32:35 +00:00
Mike Snitzer
924e600d41 dm: eliminate some holes data structures
Eliminate a 4-byte hole in 'struct dm_io_memory' by moving 'offset' above the
'ptr' to which it applies (size reduced from 24 to 16 bytes).  And by
association, 1-4 byte hole is eliminated in 'struct dm_io_request' (size
reduced from 56 to 48 bytes).

Eliminate all 6 4-byte holes and 1 cache-line in 'struct dm_snapshot' (size
reduced from 392 to 368 bytes).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:32:33 +00:00
Peter Rajnoha
3abf85b5b5 dm ioctl: introduce flag indicating uevent was generated
Set a new DM_UEVENT_GENERATED_FLAG when returning from ioctls to
indicate that a uevent was actually generated.  This tells the userspace
caller that it may need to wait for the event to be processed.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:32:31 +00:00
Mikulas Patocka
a97f925a32 dm: free dm_io before bio_endio not after
Free the dm_io structure before calling bio_endio() instead of after it,
to ensure that the io_pool containing it is not referenced after it is
freed.

This partially fixes a problem described here
  https://www.redhat.com/archives/dm-devel/2010-February/msg00109.html

thread 1:
bio_endio(bio, io_error);
/* scheduling happens */
					thread 2:
					close the device
					remove the device
thread 1:
free_io(md, io);

Thread 2, when removing the device, sees non-empty md->io_pool (because the
io hasn't been freed by thread 1 yet) and may crash with BUG in mempool_free.
Thread 1 may also crash, when freeing into a nonexisting mempool.

To fix this we must make sure that bio_endio() is the last call and
the md structure is not accessed afterwards.

There is another bio_endio in process_barrier, but it is called from the thread
and the thread is destroyed prior to freeing the mempools, so this call is
not affected by the bug.

A similar bug exists with module unloads - the module may be unloaded
immediately after bio_endio - but that is more difficult to fix.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:32:29 +00:00
Nikanth Karthikesan
8215d6ec5f dm table: remove unused dm_get_device range parameters
Remove unused parameters(start and len) of dm_get_device()
and fix the callers.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:32:27 +00:00
Mike Snitzer
0f3649a9e3 dm ioctl: only issue uevent on resume if state changed
Only issue a uevent on a resume if the state of the device changed,
i.e. if it was suspended and/or its table was replaced.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:32:24 +00:00
Mikulas Patocka
ede5ea0b8b dm raid1: always return error if all legs fail
If all mirror legs fail, always return an error instead of holding the
bio, even if the handle_errors option was set.  At present it is the
responsibility of the driver underneath us to deal with retries,
multipath etc.

The patch adds the bio to the failures list instead of holding it
directly.  do_failures tests first if all legs failed and, if so,
returns the bio with -EIO.  If any leg is still alive and handle_errors
is set, do_failures calls hold_bio.

Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:32:22 +00:00
Kiyoshi Ueda
fb61264297 dm mpath: refactor pg_init
This patch pulls the pg_init path activation code out of
process_queued_ios() into a new function.

No functional change.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:32:18 +00:00
Kiyoshi Ueda
2bded7bd7e dm mpath: wait for pg_init completion when suspending
When suspending the device we must wait for all I/O to complete, but
pg-init may be still in progress even after flushing the workqueue
for kmpath_handlerd in multipath_postsuspend.

This patch waits for pg-init completion correctly in
multipath_postsuspend().

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:32:13 +00:00
Kiyoshi Ueda
d0259bf0ee dm mpath: hold io until all pg_inits completed
m->queue_io is set to block processing I/Os, and it needs to be kept
while pg-init, which issues multiple path activations, is in progress.
But m->queue is cleared when a path activation completes without error
in pg_init_done(), even while other path activations are in progress.
That may cause undesired -EIO on paths which are not complete activation.

This patch fixes that by not clearing m->queue_io until all path
activations complete.

(Before the hardware handlers were moved into the SCSI layer, pg_init
only used one path.)

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:30:02 +00:00
Kiyoshi Ueda
fce323dd68 dm mpath: avoid storing private suspended state
'suspended' flag in struct multipath was introduced to check whether
the multipath target is in suspended state, but the same check is
done through dm_suspended() now, so remove the flag and related code.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:29:59 +00:00
Kiyoshi Ueda
ecdb2e257a dm table: remove dm_get from dm_table_get_md
Remove the dm_get() in dm_table_get_md() because dm_table_get_md() could
be called from presuspend/postsuspend, which are called while
mapped_device is in DMF_FREEING state, where dm_get() is not allowed.

Justification for that is the lifetime of both objects: As far as the
current dm design/implementation, mapped_device is never freed while
targets are doing something, because dm core waits for targets to become
quiet in dm_put() using presuspend/postsuspend.  So targets should be
able to touch mapped_device without holding reference count of the
mapped_device, and we should allow targets to touch mapped_device even
if it is in DMF_FREEING state.

Backgrounds:
I'm trying to remove the multipath internal queue, since dm core now has
a generic queue for request-based dm.  In the patch-set, the multipath
target wants to request dm core to start/stop queue.  One of such
start/stop requests can happen during postsuspend() while the target
waits for pg-init to complete, because the target stops queue when
starting pg-init and tries to restart it when completing pg-init.  Since
queue belongs to mapped_device, it involves calling dm_table_get_md()
and dm_put().  On the other hand, postsuspend() is called in dm_put()
for mapped_device which is in DMF_FREEING state, and that triggers
BUG_ON(DMF_FREEING) in the 2nd dm_put().

I had tried to solve this problem by changing only multipath not to
touch mapped_device which is in DMF_FREEING state, but I couldn't and I
came up with a question why we need dm_get() in dm_table_get_md().

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:29:52 +00:00
Moger, Babu
f7b934c812 dm mpath: skip activate_path for failed paths
This patch adds two minor fixes while processing device mapper path activation.

Skip failed paths while calling activate_path.  If the path is already failed
then activate_path will fail for sure. We don't have to call in that case. In
some case this might cause prolonged retries unnecessarily.

Change the misleading message if the path being activated fails with SCSI_DH_NOSYS.

Signed-off-by: Babu Moger <babu.moger@lsi.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:29:49 +00:00
Moger, Babu
83c0d5d538 dm mpath: pass struct pgpath to pg init done
This patch removes some unnecessary argument casting. There is no
functional change with this patch.

Passes 'struct pgpath' through to pg_init_done() instead of the enclosed
'struct dm_path'.

Tested the changes with LSI storage..

CC: Chandra Seetharaman <chandra.seetharaman@us.ibm.com>
Signed-off-by: Babu Moger <babu.moger@lsi.com>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-03-06 02:29:45 +00:00
Linus Torvalds
0a135ba14d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: add __percpu sparse annotations to what's left
  percpu: add __percpu sparse annotations to fs
  percpu: add __percpu sparse annotations to core kernel subsystems
  local_t: Remove leftover local.h
  this_cpu: Remove pageset_notifier
  this_cpu: Page allocator conversion
  percpu, x86: Generic inc / dec percpu instructions
  local_t: Move local.h include to ringbuffer.c and ring_buffer_benchmark.c
  module: Use this_cpu_xx to dynamically allocate counters
  local_t: Remove cpu_local_xx macros
  percpu: refactor the code in pcpu_[de]populate_chunk()
  percpu: remove compile warnings caused by __verify_pcpu_ptr()
  percpu: make accessors check for percpu pointer in sparse
  percpu: add __percpu for sparse.
  percpu: make access macros universal
  percpu: remove per_cpu__ prefix.
2010-03-03 07:34:18 -08:00
Martin K. Petersen
8a78362c4e block: Consolidate phys_segment and hw_segment limits
Except for SCSI no device drivers distinguish between physical and
hardware segment limits.  Consolidate the two into a single segment
limit.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-02-26 13:58:08 +01:00
Martin K. Petersen
086fa5ff08 block: Rename blk_queue_max_sectors to blk_queue_max_hw_sectors
The block layer calling convention is blk_queue_<limit name>.
blk_queue_max_sectors predates this practice, leading to some confusion.
Rename the function to appropriately reflect that its intended use is to
set max_hw_sectors.

Also introduce a temporary wrapper for backwards compability.  This can
be removed after the merge window is closed.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-02-26 13:58:08 +01:00
Tejun Heo
a29d8b8e2d percpu: add __percpu sparse annotations to what's left
Add __percpu sparse annotations to places which didn't make it in one
of the previous patches.  All converions are trivial.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors.  This patch doesn't affect normal builds.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Neil Brown <neilb@suse.de>
2010-02-17 11:17:38 +09:00
Alasdair G Kergon
9307f6b19a dm: sysfs revert add empty release function to avoid debug warning
Revert commit d2bb7df8ca at Greg's request.

    Author: Milan Broz <mbroz@redhat.com>
    Date:   Thu Dec 10 23:51:53 2009 +0000

    dm: sysfs add empty release function to avoid debug warning

    This patch just removes an unnecessary warning:
     kobject: 'dm': does not have a release() function,
     it is broken and must be fixed.

    The kobject is embedded in mapped device struct, so
    code does not need to release memory explicitly here.

Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-02-16 18:43:04 +00:00
Kiyoshi Ueda
9eef87da2a dm mpath: fix stall when requeueing io
This patch fixes the problem that system may stall if target's ->map_rq
returns DM_MAPIO_REQUEUE in map_request().
E.g. stall happens on 1 CPU box when a dm-mpath device with queue_if_no_path
     bounces between all-paths-down and paths-up on I/O load.

When target's ->map_rq returns DM_MAPIO_REQUEUE, map_request() requeues
the request and returns to dm_request_fn().  Then, dm_request_fn()
doesn't exit the I/O dispatching loop and continues processing
the requeued request again.
This map and requeue loop can be done with interrupt disabled,
so 1 CPU system can be stalled if this situation happens.

For example, commands below can stall my 1 CPU box within 1 minute or so:
  # dmsetup table mp
  mp: 0 2097152 multipath 1 queue_if_no_path 0 1 1 service-time 0 1 2 8:144 1 1
  # while true; do dd if=/dev/mapper/mp of=/dev/null bs=1M count=100; done &
  # while true; do \
  > dmsetup message mp 0 "fail_path 8:144" \
  > dmsetup suspend --noflush mp \
  > dmsetup resume mp \
  > dmsetup message mp 0 "reinstate_path 8:144" \
  > done

To fix the problem above, this patch changes dm_request_fn() to exit
the I/O dispatching loop once if a request is requeued in map_request().

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-02-16 18:43:01 +00:00
Takahiro Yasui
558569aa9d dm raid1: fix null pointer dereference in suspend
When suspending a failed mirror, bios are completed by mirror_end_io() and
__rh_lookup() in dm_rh_dec() returns NULL where a non-NULL return value is
required by design.  Fix this by not changing the state of the recovery failed
region from DM_RH_RECOVERING to DM_RH_NOSYNC in dm_rh_recovery_end().

Issue

On 2.6.33-rc1 kernel, I hit the bug when I suspended the failed
mirror by dmsetup command.

BUG: unable to handle kernel NULL pointer dereference at 00000020
IP: [<f94f38e2>] dm_rh_dec+0x35/0xa1 [dm_region_hash]
...
EIP: 0060:[<f94f38e2>] EFLAGS: 00010046 CPU: 0
EIP is at dm_rh_dec+0x35/0xa1 [dm_region_hash]
EAX: 00000286 EBX: 00000000 ECX: 00000286 EDX: 00000000
ESI: eff79eac EDI: eff79e80 EBP: f6915cd4 ESP: f6915cc4
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process dmsetup (pid: 2849, ti=f6914000 task=eff03e80 task.ti=f6914000)
 ...
Call Trace:
 [<f9530af6>] ? mirror_end_io+0x53/0x1b1 [dm_mirror]
 [<f9413104>] ? clone_endio+0x4d/0xa2 [dm_mod]
 [<f9530aa3>] ? mirror_end_io+0x0/0x1b1 [dm_mirror]
 [<f94130b7>] ? clone_endio+0x0/0xa2 [dm_mod]
 [<c02d6bcb>] ? bio_endio+0x28/0x2b
 [<f952f303>] ? hold_bio+0x2d/0x62 [dm_mirror]
 [<f952f942>] ? mirror_presuspend+0xeb/0xf7 [dm_mirror]
 [<c02aa3e2>] ? vmap_page_range+0xb/0xd
 [<f9414c8d>] ? suspend_targets+0x2d/0x3b [dm_mod]
 [<f9414ca9>] ? dm_table_presuspend_targets+0xe/0x10 [dm_mod]
 [<f941456f>] ? dm_suspend+0x4d/0x150 [dm_mod]
 [<f941767d>] ? dev_suspend+0x55/0x18a [dm_mod]
 [<c0343762>] ? _copy_from_user+0x42/0x56
 [<f9417fb0>] ? dm_ctl_ioctl+0x22c/0x281 [dm_mod]
 [<f9417628>] ? dev_suspend+0x0/0x18a [dm_mod]
 [<f9417d84>] ? dm_ctl_ioctl+0x0/0x281 [dm_mod]
 [<c02c3c4b>] ? vfs_ioctl+0x22/0x85
 [<c02c422c>] ? do_vfs_ioctl+0x4cb/0x516
 [<c02c42b7>] ? sys_ioctl+0x40/0x5a
 [<c0202858>] ? sysenter_do_call+0x12/0x28

Analysis

When recovery process of a region failed, dm_rh_recovery_end() function
changes the state of the region from RM_RH_RECOVERING to DM_RH_NOSYNC.
When recovery_complete() is executed between dm_rh_update_states() and
dm_writes() in do_mirror(), bios are processed with the region state,
DM_RH_NOSYNC. However, the region data is freed without checking its
pending count when dm_rh_update_states() is called next time.

When bios are finished by mirror_end_io(), __rh_lookup() in dm_rh_dec()
returns NULL even though a valid return value are expected.

Solution

Remove the state change of the recovery failed region from DM_RH_RECOVERING
to DM_RH_NOSYNC in dm_rh_recovery_end(). We can remove the state change
because:

  - If the region data has been released by dm_rh_update_states(),
    a new region data is created with the state of DM_RH_NOSYNC, and
    bios are processed according to the DM_RH_NOSYNC state.

  - If the region data has not been released by dm_rh_update_states(),
    a state of the region is DM_RH_RECOVERING and bios are put in the
    delayed_bio list.

The flag change from DM_RH_RECOVERING to DM_RH_NOSYNC in dm_rh_recovery_end()
was added in the following commit:
  dm raid1: handle resync failures
  author  Jonathan Brassow <jbrassow@redhat.com>
    Thu, 12 Jul 2007 16:29:04 +0000 (17:29 +0100)
  http://git.kernel.org/linus/f44db678edcc6f4c2779ac43f63f0b9dfa28b724

Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-02-16 18:42:58 +00:00
Mikulas Patocka
5528d17de1 dm raid1: fail writes if errors are not handled and log fails
If the mirror log fails when the handle_errors option was not selected
and there is no remaining valid mirror leg, writes return success even
though they weren't actually written to any device.  This patch
completes them with EIO instead.

This code path is taken:
do_writes:
	bio_list_merge(&ms->failures, &sync);
do_failures:
	if (!get_valid_mirror(ms)) (false)
	else if (errors_handled(ms)) (false)
	else bio_endio(bio, 0);

The logic in do_failures is based on presuming that the write was already
tried: if it succeeded at least on one leg (without handle_errors) it
is reported as success.

Reference: https://bugzilla.redhat.com/show_bug.cgi?id=555197

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-02-16 18:42:55 +00:00
Jonathan Brassow
ebfd32bba9 dm log: userspace fix overhead_size calcuations
This patch fixes two bugs that revolve around the miscalculation and
misuse of the variable 'overhead_size'.  'overhead_size' is the size of
the various header structures used during communication.

The first bug is the use of 'sizeof' with the pointer of a structure
instead of the structure itself - resulting in the wrong size being
computed.  This is then used in a check to see if the payload
(data_size) would be to large for the preallocated structure.  Since the
bug produces a smaller value for the overhead, it was possible for the
structure to be breached.  (Although the current users of the code do
not currently send enough data to trigger this bug.)

The second bug is that the 'overhead_size' value is used to compute how
much of the preallocated space should be cleared before populating it
with fresh data.  This should have simply been 'sizeof(struct cn_msg)'
not overhead_size.  The fact that 'overhead_size' was computed
incorrectly made this problem "less bad" - leaving only a pointer's
worth of space at the end uncleared.  Thus, this bug was never producing
a bad result, but still needs to be fixed - especially now that the
value is computed correctly.

Cc: stable@kernel.org
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-02-16 18:42:53 +00:00
Mike Snitzer
55f67f2ded dm snapshot: persistent annotate work_queue as on stack
chunk_io() declares its 'struct mdata_req' on the stack and then
initializes its 'struct work_struct' member.  Annotate the
initialization of this workqueue with INIT_WORK_ON_STACK to suppress a
debugobjects warning seen when CONFIG_DEBUG_OBJECTS_WORK is enabled.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-02-16 18:42:51 +00:00
Nikanth Karthikesan
781248c1b5 dm stripe: avoid divide by zero with invalid stripe count
If a table containing zero as stripe count is passed into stripe_ctr
the code attempts to divide by zero.

This patch changes DM_TABLE_LOAD to return -EINVAL if the stripe count
is zero.

We now get the following error messages:
  device-mapper: table: 253:0: striped: Invalid stripe count
  device-mapper: ioctl: error adding target to table

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-02-16 18:42:47 +00:00
NeilBrown
ef286f6fa6 md: fix some lockdep issues between md and sysfs.
======
This fix is related to
    http://bugzilla.kernel.org/show_bug.cgi?id=15142
but does not address that exact issue.
======

sysfs does like attributes being removed while they are being accessed
(i.e. read or written) and waits for the access to complete.

As accessing some md attributes takes the same lock that is held while
removing those attributes a deadlock can occur.

This patch addresses 3 issues in md that could lead to this deadlock.

Two relate to calling flush_scheduled_work while the lock is held.
This is probably a bad idea in general and as we use schedule_work to
delete various sysfs objects it is particularly bad.

In one case flush_scheduled_work is called from md_alloc (called by
md_probe) called from do_md_run which holds the lock.  This call is
only present to ensure that ->gendisk is set.  However we can be sure
that gendisk is always set (though possibly we couldn't when that code
was originally written.  This is because do_md_run is called in three
different contexts:
  1/ from md_ioctl.  This requires that md_open has succeeded, and it
     fails if ->gendisk is not set.
  2/ from writing a sysfs attribute.  This can only happen if the
     mddev has been registered in sysfs which happens in md_alloc
     after ->gendisk has been set.
  3/ from autorun_array which is only called by autorun_devices, which
     checks for ->gendisk to be set before calling autorun_array.
So the call to md_probe in do_md_run can be removed, and the check on
->gendisk can also go.


In the other case flush_scheduled_work is being called in do_md_stop,
purportedly to wait for all md_delayed_delete calls (which delete the
component rdevs) to complete.  However there really isn't any need to
wait for them - they have already been disconnected in all important
ways.

The third issue is that raid5->stop() removes some attribute names
while the lock is held.  There is already some infrastructure in place
to delay attribute removal until after the lock is released (using
schedule_work).  So extend that infrastructure to remove the
raid5_attrs_group.

This does not address all lockdep issues related to the sysfs
"s_active" lock.  The rest can be address by splitting that lockdep
context between symlinks and non-symlinks which hopefully will happen.

Signed-off-by: NeilBrown <neilb@suse.de>
2010-02-10 11:26:09 +11:00
NeilBrown
9eb07c2592 md: fix 'degraded' calculation when starting a reshape.
This code was written long ago when it was not possible to
reshape a degraded array.  Now it is so the current level of
degraded-ness needs to be taken in to account.  Also newly addded
devices should only reduce degradedness if they are deemed to be
in-sync.

In particular, if you convert a RAID5 to a RAID6, and increase the
number of devices at the same time, then the 5->6 conversion will
make the array degraded so the current code will produce a wrong
value for 'degraded' - "-1" to be precise.

If the reshape runs to completion end_reshape will calculate a correct
new value for 'degraded', but if a device fails during the reshape an
incorrect decision might be made based on the incorrect value of
"degraded".

This patch is suitable for 2.6.32-stable and if they are still open,
2.6.31-stable and 2.6.30-stable as well.

Cc: stable@kernel.org
Reported-by: Michael Evans <mjevans1983@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2010-02-09 16:34:29 +11:00
Martin K. Petersen
b27d7f16d3 DM: Fix device mapper topology stacking
Make DM use bdev_stack_limits() function so that partition offsets get
taken into account when calculating alignment.  Clarify stacking
warnings.

Also remove obsolete clearing of final alignment_offset and misalignment
flag.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair G. Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-01-11 14:29:20 +01:00
NeilBrown
404e4b43fd md: allow a resync that is waiting for other resync to complete, to be aborted.
If two arrays share a device, then they will not both resync at the
same time.  One will wait for the other to complete.
While waiting, the MD_RECOVERY_INTR flag is not checked so a device
failure, which would make the resync pointless, does not cause the
resync to abort, so the failed device cannot be removed (as it cannot
be remove while a resync is happening).

So add a test for MD_RECOVERY_INTR.

Reported-by: Brett Russ <bruss@netezza.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:25:23 +11:00
NeilBrown
7fb9dadc91 md: remove unnecessary code from do_md_run
Since commit dfc7064500,
->hot_remove_disks has not removed non-failed devices from
an array until recovery is no longer possible.
So the code in do_md_run to get around the fact that
md_check_recovery (which calls ->hot_remove_disks) would
remove partially-in-sync devices is no longer needed.

So remove it.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:20:43 +11:00
Dan Williams
a2d79c324a md: make recovery started by do_md_run() visible via sync_action
By default md_do_sync() will perform recovery if no other actions are
specified.  However, action_show() relies on MD_RECOVERY_RECOVER to be
set otherwise it returns 'idle'.  So, add a missing set
MD_RECOVERY_RECOVER when starting recovery.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:20:31 +11:00
NeilBrown
0f9552b5dc md: fix small irregularity with start_ro module parameter
The start_ro modules parameter can be used to force arrays to be
started in 'auto-readonly' in which they are read-only until the first
write.  This ensures that no resync/recovery happens until something
else writes to the device.  This is important for resume-from-disk
off an md array.

However if an array is started 'readonly' (by writing 'readonly' to
the 'array_state' sysfs attribute) we want it to be really 'readonly',
not 'auto-readonly'.

So strengthen the condition to only set auto-readonly if the
array is not already read-only.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30 15:20:12 +11:00
NeilBrown
cbd1998377 md: Fix unfortunate interaction with evms
evms configures md arrays by:
  open device
  send ioctl
  close device

for each different ioctl needed.
Since 2.6.29, the device can disappear after the 'close'
unless a significant configuration has happened to the device.
The change made by "SET_ARRAY_INFO" can too minor to stop the device
from disappearing, but important enough that losing the change is bad.

So: make sure SET_ARRAY_INFO sets mddev->ctime, and keep the device
active as long as ctime is non-zero (it gets zeroed with lots of other
things when the array is stopped).

This is suitable for -stable kernels since 2.6.29.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2009-12-30 12:08:49 +11:00
Linus Torvalds
53365383c4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (80 commits)
  dm snapshot: use merge origin if snapshot invalid
  dm snapshot: report merge failure in status
  dm snapshot: merge consecutive chunks together
  dm snapshot: trigger exceptions in remaining snapshots during merge
  dm snapshot: delay merging a chunk until writes to it complete
  dm snapshot: queue writes to chunks being merged
  dm snapshot: add merging
  dm snapshot: permit only one merge at once
  dm snapshot: support barriers in snapshot merge target
  dm snapshot: avoid allocating exceptions in merge
  dm snapshot: rework writing to origin
  dm snapshot: add merge target
  dm exception store: add merge specific methods
  dm snapshot: create function for chunk_is_tracked wait
  dm snapshot: make bio optional in __origin_write
  dm mpath: reject messages when device is suspended
  dm: export suspended state to targets
  dm: rename dm_suspended to dm_suspended_md
  dm: swap target postsuspend call and setting suspended flag
  dm crypt: add plain64 iv
  ...
2009-12-15 09:12:01 -08:00
Joe Perches
7b75c2f8cf drivers/md/md.c: use %pU to print UUIDs
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:33 -08:00
André Goddard Rosa
e7d2860b69 tree-wide: convert open calls to remove spaces to skip_spaces() lib function
Makes use of skip_spaces() defined in lib/string.c for removing leading
spaces from strings all over the tree.

It decreases lib.a code size by 47 bytes and reuses the function tree-wide:
   text    data     bss     dec     hex filename
  64688     584     592   65864   10148 (TOTALS-BEFORE)
  64641     584     592   65817   10119 (TOTALS-AFTER)

Also, while at it, if we see (*str && isspace(*str)), we can be sure to
remove the first condition (*str) as the second one (isspace(*str)) also
evaluates to 0 whenever *str == 0, making it redundant. In other words,
"a char equals zero is never a space".

Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below,
and found occurrences of this pattern on 3 more files:
    drivers/leds/led-class.c
    drivers/leds/ledtrig-timer.c
    drivers/video/output.c

@@
expression str;
@@

( // ignore skip_spaces cases
while (*str &&  isspace(*str)) { \(str++;\|++str;\) }
|
- *str &&
isspace(*str)
)

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Julia Lawall <julia@diku.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Neil Brown <neilb@suse.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: David Howells <dhowells@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:32 -08:00
Dan Williams
06e3c817b7 md: add 'recovery_start' per-device sysfs attribute
Enable external metadata arrays to manage rebuild checkpointing via a
md/dev-XXX/recovery_start attribute which reflects rdev->recovery_offset

Also update resync_start_store to allow 'none' to be written, for
consistency.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:58:57 +11:00
Dan Williams
4e59ca7da0 md: rcu_read_lock() walk of mddev->disks in md_do_sync()
Other walks of this list are either under rcu_read_lock() or the list
mutation lock (mddev_lock()).  This protects against the improbable case of a
disk being removed from the array at the start of md_do_sync().

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-12-14 12:57:43 +11:00
NeilBrown
93be75ffde md: integrate spares into array at earliest opportunity.
As v1.x metadata can record that a member of the array is
not completely recovered, it make sense to record that a
spare has become a regular member of the array at the earliest
opportunity.
So remove the tests on "recovery_offset > 0" in super_1_sync
as they really aren't needed, and schedule a metadata update
immediately after adding spares to a degraded array.

This means that if a crash happens immediately after a recovery
starts, the new device will be included in the array and recovery will
continue from wherever it was up to.  Previously this didn't happen
unless recovery was at least 1/16 of the way through.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
Arnd Bergmann
aa98aa3198 md: move compat_ioctl handling into md.c
The RAID ioctls are only implemented in md.c, so the
handling for them should also be moved there from
fs/compat_ioctl.c.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Neil Brown <neilb@suse.de>
Cc: Andre Noll <maan@systemlinux.org>
Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
93bd89a6d5 md: revise Kconfig help for MD_MULTIPATH
Make it clear in the config message that MD_MULTIPATH is not under
active development.

Cc: Oren Held <orenhe@il.ibm.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
0efb9e6191 md: add MODULE_DESCRIPTION for all md related modules.
Suggested by  Oren Held <orenhe@il.ibm.com>

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
Robert Becker
1e50915fe0 raid: improve MD/raid10 handling of correctable read errors.
We've noticed severe lasting performance degradation of our raid
arrays when we have drives that yield large amounts of media errors.
The raid10 module will queue each failed read for retry, and also
will attempt call fix_read_error() to perform the read recovery.
Read recovery is performed while the array is frozen, so repeated
recovery attempts can degrade the performance of the array for
extended periods of time.

With this patch I propose adding a per md device max number of
corrected read attempts.  Each rdev will maintain a count of
read correction attempts in the rdev->read_errors field (not
used currently for raid10). When we enter fix_read_error()
we'll check to see when the last read error occurred, and
divide the read error count by 2 for every hour since the
last read error. If at that point our read error count
exceeds the read error threshold, we'll fail the raid device.

In addition in this patch I add sysfs nodes (get/set) for
the per md max_read_errors attribute, the rdev->read_errors
attribute, and added some printk's to indicate when
fix_read_error fails to repair an rdev.

For testing I used debugfs->fail_make_request to inject
IO errors to the rdev while doing IO to the raid array.

Signed-off-by: Robert Becker <Rob.Becker@riverbed.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
Robert Becker
67b8dc4b06 md/raid10: print more useful messages on device failure.
When we get a read error on a device in a RAID10, and attempting to
repair the error fails, print more useful messages about why it
failed.

Signed-off-by: Robert Becker <Rob.Becker@riverbed.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
ffa23322b1 md/bitmap: update dirty flag when bitmap bits are explicitly set.
There is a sysfs file which allows bits in the write-intent
bitmap to be explicit set - indicating that the block is thought
to be 'dirty'.
When this happens we should really set recovery_cp backwards
to include the block to reflect this dirtiness.

In particular, a 'resync' process will refuse to start if
recovery_cp is beyond the end of the array, so this is needed
to allow a resync to be triggered.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
ece5cff0da md: Support write-intent bitmaps with externally managed metadata.
In this case, the metadata needs to not be in the same
sector as the bitmap.
md will not read/write any bitmap metadata.  Config must be
done via sysfs and when a recovery makes the array non-degraded
again, writing 'true' to 'bitmap/can_clear' will allow bits in
the bitmap to be cleared again.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
624ce4f565 md/bitmap: move setting of daemon_lastrun out of bitmap_read_sb
Setting daemon_lastrun really has nothing to do with reading
the bitmap superblock, it just happens to be needed at the same time.
bitmap_read_sb is about to become options, so move that code out
to after the call to bitmap_read_sb.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
43a705076e md: support updating bitmap parameters via sysfs.
A new attribute directory 'bitmap' in 'md' is created which
contains files for configuring the bitmap.
'location' identifies where the bitmap is, either 'none',
or 'file' or 'sector offset from metadata'.
Writing 'location' can create or remove a bitmap.
Adding a 'file' bitmap this way is not yet supported.
'chunksize' and 'time_base' must be set before 'location'
can be set.

'chunksize' can be set before creating a bitmap, but is
currently always over-ridden by the bitmap superblock.

'time_base' and 'backlog' can be updated at any time.


Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Andre Noll <maan@systemlinux.org>
2009-12-14 12:51:41 +11:00
NeilBrown
72e02075a3 md: factor out parsing of fixed-point numbers
safe_delay_store can parse fixed point numbers (for fractions
of a second).  We will want to do that for another sysfs
file soon, so factor out the code.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
f6af949c56 md: support bitmap offset appropriate for external-metadata arrays.
For md arrays were metadata is managed externally, the kernel does not
know about a superblock so the superblock offset is 0.
If we want to have a write-intent-bitmap near the end of the
devices of such an array, we should support sector_t sized offset.
We need offset be possibly negative for when the bitmap is before
the metadata, so use loff_t instead.

Also add sanity check that bitmap does not overlap with data.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
9cd30fdc33 md: remove needless setting of thread->timeout in raid10_quiesce
As bitmap_create and bitmap_destroy already set thread->timeout
as appropriate, there is no need to do it in raid10_quiesce.
There is a possible need to wake the thread after the timeout
has been set low, but it is better to do that where the timeout
is actually set low, in bitmap_create.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
1b04be96f6 md: change daemon_sleep to be in 'jiffies' rather than 'seconds'.
This removes a lot of multiplications by HZ.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
42a04b5078 md: move offset, daemon_sleep and chunksize out of bitmap structure
... and into bitmap_info.  These are all configuration parameters
that need to be set before the bitmap is created.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
c3d9714e88 md: collect bitmap-specific fields into one structure.
In preparation for making bitmap fields configurable via sysfs,
start tidying up by making a single structure to contain the
configuration fields.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
709ae4879a md/raid1: add takeover support for raid5->raid1
A 2-device raid5 array can now be converted to raid1.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:41 +11:00
NeilBrown
6eef4b21ff md: add honouring of suspend_{lo,hi} to raid1.
This will allow us to stop writeout to portions of the array
while  they are resynced by someone else - e.g. another node in
a cluster.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:40 +11:00
NeilBrown
729a18663a md/raid5: don't complete make_request on barrier until writes are scheduled
The post-barrier-flush is sent by md as soon as make_request on the
barrier write completes.  For raid5, the data might not be in the
per-device queues yet.  So for barrier requests, wait for any
pre-reading to be done so that the request will be in the per-device
queues.

We use the 'preread_active' count to check that nothing is still in
the preread phase, and delay the decrement of this count until after
write requests have been submitted to the underlying devices.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:51:40 +11:00
NeilBrown
a2826aa92e md: support barrier requests on all personalities.
Previously barriers were only supported on RAID1.  This is because
other levels requires synchronisation across all devices and so needed
a different approach.
Here is that approach.

When a barrier arrives, we send a zero-length barrier to every active
device.  When that completes - and if the original request was not
empty -  we submit the barrier request itself (with the barrier flag
cleared) and then submit a fresh load of zero length barriers.

The barrier request itself is asynchronous, but any subsequent
request will block until the barrier completes.

The reason for clearing the barrier flag is that a barrier request is
allowed to fail.  If we pass a non-empty barrier through a striping
raid level it is conceivable that part of it could succeed and part
could fail.  That would be way too hard to deal with.
So if the first run of zero length barriers succeed, we assume all is
sufficiently well that we send the request and ignore errors in the
second run of barriers.

RAID5 needs extra care as write requests may not have been submitted
to the underlying devices yet.  So we flush the stripe cache before
proceeding with the barrier.

Note that the second set of zero-length barriers are submitted
immediately after the original request is submitted.  Thus when
a personality finds mddev->barrier to be set during make_request,
it should not return from make_request until the corresponding
per-device request(s) have been queued.

That will be done in later patches.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Andre Noll <maan@systemlinux.org>
2009-12-14 12:49:49 +11:00
NeilBrown
efa593390e md: don't reset curr_resync_completed after an interrupted resync
If a resync/recovery/check/repair is interrupted for some reason, it
can be useful to know exactly where it got up to.
So in that case, do not clear curr_resync_completed.
Initialise it when starting a resync/recovery/... instead.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:49:49 +11:00
NeilBrown
c07b70ad32 md: adjust resync_min usefully when resync aborts.
When a 'check' or 'repair' finished we should clear resync_min
so that a future check/repair will cover the whole array (by default).
However if it is interrupted, we should update resync_min to
where we got up to, so that when the check/repair continues it
just does the remainder of the array.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:49:48 +11:00
NeilBrown
7820f9e1dd md: remove sparse warning:symbol XXX was not declared.
Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:49:47 +11:00
NeilBrown
8553fe7ec7 md/raid5: remove some sparse warnings.
qd_idx is previously declared and given exactly the same value!

Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14 12:49:47 +11:00
NeilBrown
aa5cbd1038 md/bitmap: protect against bitmap removal while being updated.
A write intent bitmap can be removed from an array while the
array is active.
When this happens, all IO is suspended and flushed before the
bitmap is removed.
However it is possible that bitmap_daemon_work is still running to
clear old bits from the bitmap.  If it is, it can dereference the
bitmap after it has been freed.

So introduce a new mutex to protect bitmap_daemon_work and get it
before destroying a bitmap.

This is suitable for any current -stable kernel.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2009-12-14 12:49:46 +11:00
Mikulas Patocka
d2fdb776e0 dm snapshot: use merge origin if snapshot invalid
If the snapshot we are merging became invalid (e.g. it ran out of
space) redirect all I/O directly to the origin device.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:36 +00:00
Mike Snitzer
d8ddb1cfff dm snapshot: report merge failure in status
Set 'merge_failed' flag if a snapshot fails to merge.  Update
snapshot_status() to report "Merge failed" if 'merge_failed' is set.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:35 +00:00
Mike Snitzer
8a2d528620 dm snapshot: merge consecutive chunks together
s->store->type->prepare_merge returns the number of chunks that can be
copied linearly working backwards from the returned chunk number.

For example, if it returns 3 chunks with old_chunk == 10 and new_chunk
== 20, then chunk 20 can be copied to 10, chunk 19 to 9 and 18 to 8.

Until now kcopyd only copied one chunk at a time.  This patch now copies
the full set at once.

Consequently, snapshot_merge_process() needs to delay the merging of all
chunks if any have writes in progress, not just the first chunk in the
region that is to be merged.

snapshot-merge's performance is now comparable to the original
snapshot-origin target.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:34 +00:00
Mikulas Patocka
73dfd078cf dm snapshot: trigger exceptions in remaining snapshots during merge
When there is one merging snapshot and other non-merging snapshots,
snapshot_merge_process() must make exceptions in the non-merging
snapshots.

Use a sequence count to resolve the race between I/O to chunks that are
about to be merged.  The count increases each time an exception
reallocation finishes.  Use wait_event() to wait until the count
changes.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:34 +00:00
Mikulas Patocka
17aa03326d dm snapshot: delay merging a chunk until writes to it complete
Track writes to chunks that are currently being merged and delay merging
a chunk until all writes to that chunk finish.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:33 +00:00
Mikulas Patocka
9fe8625488 dm snapshot: queue writes to chunks being merged
While a set of chunks is being merged, any overlapping writes need to be
queued.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:33 +00:00
Mikulas Patocka
1e03f97e43 dm snapshot: add merging
Merging is started when origin is resumed and it is stopped when
origin is suspended or when the merging snapshot is destroyed or
errors are detected.

Merging is not yet interlocked with writes: this will be handled in
subsequent patches.

The code relies on callbacks from a private kcopyd thread.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:32 +00:00
Mikulas Patocka
9d3b15c4c7 dm snapshot: permit only one merge at once
Merging more than one snapshot is not supported, so prevent
this happening.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:32 +00:00
Mike Snitzer
10b8106a70 dm snapshot: support barriers in snapshot merge target
Sets num_flush_requests=2 to support flushing both the origin and cow
devices used by the snapshot-merge target.

Also, snapshot_ctr() now gets the origin device using FMODE_WRITE if the
target is snapshot-merge (which writes to the origin device).

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:31 +00:00
Mikulas Patocka
3452c2a1eb dm snapshot: avoid allocating exceptions in merge
The snapshot-merge target should not allocate new exceptions because the
intent is to merge all of its exceptions as quickly and safely as
possible.

This patch introduces the snapshot-merge mapping function and updates
__origin_write() so that it doesn't allocate exceptions on any snapshots
that are being merged.

If a write request to a merging snapshot device is to be dispatched
directly to the origin (because the chunk is not remapped or was already
merged), snapshot_merge_map() must make exceptions in other snapshots so
calls do_origin().

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:31 +00:00
Mikulas Patocka
515ad66cc4 dm snapshot: rework writing to origin
To track the completion of exceptions relating to the same location on
the device, the current code selects one exception as primary_pe, links
the other exceptions to it and uses reference counting to wait until all
the reallocations are complete.

It is considered too complicated to extend this code to handle the new
snapshot-merge target, where sets of non-overlapping chunks would also
need to become linked.

Instead, a simpler (but less efficient) approach is taken.  Bios are
linked to one exception.  When it completes, bios are simply retried,
and if other related exceptions are still outstanding, they'll get
queued again to wait for another one.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:30 +00:00
Mikulas Patocka
d698aa4500 dm snapshot: add merge target
The snapshot-merge target allows a snapshot to be merged back into the
snapshot's origin device.

One anticipated use of snapshot merging is the rollback of filesystems
to back out problematic system upgrades.

This patch adds snapshot-merge target management to both
dm_snapshot_init() and dm_snapshot_exit().  As an initial place-holder,
snapshot-merge is identical to the snapshot target.  Documentation is
provided.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:30 +00:00
Mikulas Patocka
4454a6216f dm exception store: add merge specific methods
Add functions that decide how many consecutive chunks of snapshot to
merge back into the origin next and to update the metadata afterwards.

prepare_merge provides a pointer to the most recent still-to-be-merged
chunk and returns how many previous ones are consecutive and can be
processed together.

commit_merge removes the nr_merged most-recent chunks permanently from
the exception store.  The number must not exceed that returned by
prepare_merge.

Introduce NUM_SNAPSHOT_HDR_CHUNKS to show where the snapshot header
chunk is accounted for.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:29 +00:00
Mike Snitzer
615d1eb9ca dm snapshot: create function for chunk_is_tracked wait
Move the __chunk_is_tracked() loop into a separate function as we will
also need to call it from the write path in the rare case of conflicting
writes to the same chunk.

Originally introduced in commit a8d41b59f3
("dm snapshot: fix race during exception creation").

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:29 +00:00
Mikulas Patocka
9eaae8ffbc dm snapshot: make bio optional in __origin_write
To support the merging of snapshots back into their origin we need
to trigger exceptions in other snapshots not being merged without
any incoming bio on the origin device.  The bio parameter to
__origin_write() becomes optional and the sector needs supplying
separately.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:28 +00:00
Kiyoshi Ueda
c2f3d24b78 dm mpath: reject messages when device is suspended
This patch rejects messages that can generate I/O while the device
itself is suspended.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:27 +00:00
Kiyoshi Ueda
64dbce580d dm: export suspended state to targets
This patch adds the exported dm_suspended() function so that targets
can check whether or not they are suspended.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:27 +00:00
Kiyoshi Ueda
4f186f8bbf dm: rename dm_suspended to dm_suspended_md
This patch renames dm_suspended() to dm_suspended_md() and
keeps it internal to dm.
No functional change.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:26 +00:00
Kiyoshi Ueda
4d4471cb5c dm: swap target postsuspend call and setting suspended flag
This patch moves DMF_SUSPENDED flag set before postsuspend.
No one should care about the ordering, because the flag set and
the postsuspend are protected by a single lock, md->suspend_lock,
and all strict flag-checkers take the lock.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:26 +00:00
Milan Broz
61afef614b dm crypt: add plain64 iv
The default plain IV is 32-bit only.

This plain64 IV provides a compatible mode for encrypted devices bigger
than 4TB.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:25 +00:00
Jun'ichi Nomura
6db4ccd635 dm: trace request based remapping
This patch adds a remapping trace to request-based dm.
BIO-based dm already has the equivalent tracepoint.

For example, under this dm stack (linear LV on multipath):
  # dmsetup ls --tree -o ascii
  vg-lv0 (253:1)
   `-mpath0 (253:0)
      |- (8:160)
      |- (66:80)
      |- (65:176)
      `- (65:160)

Trace of 'dd of=/dev/vg/lv0 bs=128k count=1 oflag=direct' looks like this:

without the patch:
  dd-6674  [000]   539.727384: block_bio_queue: 253,1 WS 0 + 256 [dd]
  dd-6674  [000]   539.727392: block_remap: 253,0 WS 384 + 256 <- (253,1) 0
  dd-6674  [000]   539.727394: block_bio_queue: 253,0 WS 384 + 256 [dd]
  dd-6674  [000]   539.727405: block_getrq: 253,0 WS 384 + 256 [dd]
  dd-6674  [000]   539.727409: block_plug: [dd]
  dd-6674  [000]   539.727410: block_rq_insert: 253,0 W 0 () 384 + 256 [dd]
  dd-6674  [000]   539.727416: block_rq_issue: 253,0 W 0 () 384 + 256 [dd]
  dd-6674  [000]   539.727426: block_rq_insert: 65,176 W 0 () 384 + 256 [dd]
  dd-6674  [000]   539.727427: block_rq_issue: 65,176 W 0 () 384 + 256 [dd]
  ...

and with the patch: (the line with '**' is the trace added by this patch)
  dd-6617  [002]   162.914301: block_bio_queue: 253,1 WS 0 + 256 [dd]
  dd-6617  [002]   162.914314: block_remap: 253,0 WS 384 + 256 <- (253,1) 0
  dd-6617  [002]   162.914316: block_bio_queue: 253,0 WS 384 + 256 [dd]
  dd-6617  [002]   162.914331: block_getrq: 253,0 WS 384 + 256 [dd]
  dd-6617  [002]   162.914335: block_plug: [dd]
  dd-6617  [002]   162.914337: block_rq_insert: 253,0 W 0 () 384 + 256 [dd]
  dd-6617  [002]   162.914347: block_rq_issue: 253,0 W 0 () 384 + 256 [dd]
**dd-6617  [002]   162.914356: block_rq_remap: 65,176 W 384 + 256 <- (253,0) 384
  dd-6617  [002]   162.914358: block_rq_insert: 65,176 W 0 () 384 + 256 [dd]
  dd-6617  [002]   162.914359: block_rq_issue: 65,176 W 0 () 384 + 256 [dd]
  ...

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:25 +00:00
Mike Snitzer
c1f0c183f6 dm snapshot: allow live exception store handover between tables
Permit in-use snapshot exception data to be 'handed over' from one
snapshot instance to another.  This is a pre-requisite for patches
that allow the changes made in a snapshot device to be merged back into
its origin device and also allows device resizing.

The basic call sequence is:

  dmsetup load new_snapshot (referencing the existing in-use cow device)
     - the ctr code detects that the cow is already in use and allows the
       two snapshot target instances to be linked together
  dmsetup suspend original_snapshot
  dmsetup resume new_snapshot
     - the new_snapshot becomes live, and if anything now tries to access
       the original one it will receive -EIO
  dmsetup remove original_snapshot

(There can only be two snapshot targets referencing the same cow device
simultaneously.)

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:24 +00:00
Alasdair G Kergon
042d2a9bcd dm: keep old table until after resume succeeded
When swapping a new table into place, retain the old table until
its replacement is in place.

An old check for an empty table is removed because this is enforced
in populate_table().

__unbind() becomes redundant when followed by __bind().

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:24 +00:00
Alasdair G Kergon
a794015597 dm: bind new table before destroying old
When replacing a mapped device's table during a 'resume', delay the
destruction of the old table until the new one is successfully in place.

This will make it easier for a later patch to transfer internal state
information from the old table to the new one (something we do not currently
support) while giving us more options for reversion if a later part
of the operation fails.

Devices are always in the suspended state during dm_swap_table().
This patch reinforces the requirement that all I/O must have been
flushed from the table targets while in this state (including any in
workqueues).  In the case of 'noflush' suspending, unprocessed
I/O should have been 'pushed back' to the dm core prior to this point,
for resubmission after the new table is in place.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:23 +00:00
Mike Snitzer
1d0f3ce832 dm ioctl: retrieve status from inactive table
Add the flag DM_QUERY_INACTIVE_TABLE_FLAG to the ioctls to return
infomation about the loaded-but-not-yet-active table instead of the live
table.  Prior to this patch it was impossible to obtain this information
until the device had been 'resumed'.

Userspace dmsetup and libdevmapper support the flag as of version 1.02.40.
e.g. dmsetup info --inactive vg1-lv1

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:22 +00:00
Mikulas Patocka
12fc0f49dc dm io: handle empty barriers
Accept empty barriers in dm-io.

dm-io will process empty write barrier requests just like the other
read/write requests.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:22 +00:00
Mike Anderson
67a46dad25 dm mpath: prevent io from work queue while suspended
Reject messages that can generate I/O while the device itself
is suspended.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:21 +00:00
Mike Anderson
6380f26f04 dm mpath: add mutex to synchronize adding and flushing work
Add a mutex to allow possible creators of new work to synchronize with
flushing work queues.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:21 +00:00
Mike Anderson
c50abeb380 dm ioctl: forbid messages to devices being deleted
Once we begin deleting a device, prevent any further messages being sent
to targets of its table (to avoid races).

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:20 +00:00
Mike Anderson
432a212c0d dm: add dm_deleting_md function
Add dm_deleting_md to check whether or not a given mapped
device is currently being deleted.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:20 +00:00
Kiyoshi Ueda
6df400ab64 dm mpath: flush workqueues before suspend completes
This patch stops the remaining dm-mpath activity during the suspend
sequence by flushing workqueues in postsuspend function.

The current dm-mpath target may not be quiet even after suspend completes
because some workqueues (e.g. device_handler's work, event handling)
are not flushed during the suspend sequence, even though suspended
devices/targets are supposed to be quiet in this state.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:19 +00:00
Alasdair G Kergon
7c6664114b dm: rename dm_get_table to dm_get_live_table
Rename dm_get_table to dm_get_live_table.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:19 +00:00
Kiyoshi Ueda
d0bcb87865 dm: add request based barrier support
This patch adds barrier support for request-based dm.

CORE DESIGN

The design is basically same as bio-based dm, which emulates barrier
by mapping empty barrier bios before/after a barrier I/O.
But request-based dm has been using struct request_queue for I/O
queueing, so the block-layer's barrier mechanism can be used.

o Summary of the block-layer's behavior (which is depended by dm-core)
  Request-based dm uses QUEUE_ORDERED_DRAIN_FLUSH ordered mode for
  I/O barrier.  It means that when an I/O requiring barrier is found
  in the request_queue, the block-layer makes pre-flush request and
  post-flush request just before and just after the I/O respectively.

  After the ordered sequence starts, the block-layer waits for all
  in-flight I/Os to complete, then gives drivers the pre-flush request,
  the barrier I/O and the post-flush request one by one.
  It means that the request_queue is stopped automatically by
  the block-layer until drivers complete each sequence.

o dm-core
  For the barrier I/O, treats it as a normal I/O, so no additional
  code is needed.

  For the pre/post-flush request, flushes caches by the followings:
    1. Make the number of empty barrier requests required by target's
       num_flush_requests, and map them (dm_rq_barrier()).
    2. Waits for the mapped barriers to complete (dm_rq_barrier()).
       If error has occurred, save the error value to md->barrier_error
       (dm_end_request()).
       (*) Basically, the first reported error is taken.
           But -EOPNOTSUPP supersedes any error and DM_ENDIO_REQUEUE
           follows.
    3. Requeue the pre/post-flush request if the error value is
       DM_ENDIO_REQUEUE.  Otherwise, completes with the error value
       (dm_rq_barrier_work()).
  The pre/post-flush work above is done in the kernel thread (kdmflush)
  context, since memory allocation which might sleep is needed in
  dm_rq_barrier() but sleep is not allowed in dm_request_fn(), which is
  an irq-disabled context.
  Also, clones of the pre/post-flush request share an original, so
  such clones can't be completed using the softirq context.
  Instead, complete them in the context of underlying device drivers.
  It should be safe since there is no I/O dispatching during
  the completion of such clones.

  For suspend, the workqueue of kdmflush needs to be flushed after
  the request_queue has been stopped.  Otherwise, the next flush work
  can be kicked even after the suspend completes.

TARGET INTERFACE

No new interface is added.
Just use the existing num_flush_requests in struct target_type
as same as bio-based dm.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:18 +00:00
Kiyoshi Ueda
980691e5f3 dm: move dm_end_request
This patch moves dm_end_request() to make the next patch more readable.
No functional change.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:17 +00:00
Kiyoshi Ueda
11a68244e1 dm: refactor request based completion functions
This patch factors out the clone completion code, dm_done(),
from dm_softirq_done() in preparation for a subsequent patch.
No functional change.

dm_done() will be used in barrier completion, which can't use and
doesn't need softirq.  The softirq_done callback needs to get a clone
from an original request but it can't in the case of barrier, where
an original request is shared by multiple clones.  On the other hand,
the completion of barrier clones doesn't involve re-submitting requests,
which was the primary reason of the need for softirq.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:17 +00:00
Kiyoshi Ueda
b4324feeae dm: use md pending for in flight IO counting
This patch changes the counter for the number of in_flight I/Os
to md->pending from q->in_flight in preparation for a later patch.
No functional change.

Request-based dm used q->in_flight to count the number of in-flight
clones assuming the counter is always incremented for an in-flight
original request and original:clone is 1:1 relationship.
However, it this no longer true for barrier requests.
So use md->pending to count the number of in-flight clones.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:16 +00:00
Kiyoshi Ueda
9f518b27cf dm: simplify request based suspend
The semantics of bio-based dm were changed recently in the case of
suspend with "--nolockfs" but without "--noflush".
Before 2.6.30, I/Os submitted before the suspend invocation were always
flushed.  From 2.6.30 onwards, I/Os submitted before the suspend
invocation might not be flushed.  (For details, see
http://marc.info/?t=123994433400003&r=1&w=2)

This patch brings the behaviour of request-based dm into line with
bio-based dm, simplifying the code and preparing for a subsequent patch
that will wait for all in_flight I/Os to complete without stopping
request_queue and use dm_wait_for_completion() for it.

This change in semantics simplifies the suspend code as follows:
  o Suspend is implemented as stopping request_queue
    in request-based dm, and all I/Os are queued in the request_queue
    even after suspend is invoked.
  o In the old semantics, we had to track whether I/Os were
    queued before or after the suspend invocation, so a special
    barrier-like request called 'suspend marker' was introduced.
  o With the new semantics, we don't need to flush any I/O
    so we can remove the marker and the code related to the marker
    handling and I/O flushing.

After removing this codes, the suspend sequence is now:
  1. Flush all I/Os by lock_fs() if needed.
  2. Stop dispatching any I/O by stopping the request_queue.
  3. Wait for all in-flight I/Os to be completed or requeued.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:16 +00:00
Kiyoshi Ueda
6facdaff22 dm: abstract clone_rq
This patch factors out the request cloning code in dm_prep_fn()
as clone_rq().  No functional change.

This patch is a preparation for a later patch in this series which needs to
make clones from an original barrier request.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:15 +00:00
Kiyoshi Ueda
0888564393 dm: pass gfp_mask to alloc_rq_tio
This patch adds the gfp_mask argument to alloc_rq_tio().
No functional change.

This patch is a preparation for a later patch in this series which needs to
allocate tio (for barrier I/O) with different allocation flag (GFP_NOIO) from
the one in the normal I/O code path.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:15 +00:00
Kiyoshi Ueda
598de40947 dm: use clone in map_request function
This patch changes the argument of map_request() to clone request
from original request.  No functional change.

This patch is a preparation for PATCH 9, which needs to use
map_request() for clones sharing an original barrier request.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:14 +00:00
Kiyoshi Ueda
90abb8c4ce dm: abstract dm_in_flight function
This patch adds md_in_flight() to get the number of in_flight I/Os.
No functional change.

This patch is a preparation for a later patch in this series, which
changes I/O counter to md->pending from q->in_flight in request-based dm.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:13 +00:00
Mikulas Patocka
9ca170a3c0 dm kcopyd: accept zero size jobs
dm-kcopyd: accept zero-size jobs

This patch changes dm-kcopyd so that it accepts zero-size jobs and completes
them immediatelly via its completion thread.

It is needed for multisnapshots snapshot resizing. When we are writing to
a chunk beyond origin end, no copying is done. To simplify the code, we submit
an empty request to kcopyd and let kcopyd complete it. If we didn't submit
a request to kcopyd and called the completion routine immediatelly, it would
violate the principle that completion is called only from one thread and
it would need additional locking.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:13 +00:00
Mike Snitzer
c26655ca3c dm snapshot: track suspended state in target
Keep track of whether or not the device is suspended within the snapshot
target module, the same as we do in dm-raid1.

We will use this later to enforce the correct sequence of ioctls to
transfer the in-core exceptions from a snapshot target instance in
one table to a replacement one capable of merging them back
into the origin.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:12 +00:00
Mike Snitzer
fc56f6fbcc dm snapshot: move cow ref from exception store to snap core
Store the reference to the snapshot cow device in the core snapshot
code instead of each exception store.  It can be accessed through the
new function dm_snap_cow().  Exception stores should each now maintain a
reference to their parent snapshot struct.

This is cleaner and makes part of the forthcoming snapshot merge code simpler.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
2009-12-10 23:52:12 +00:00
Mike Snitzer
985903bb3a dm snapshot: add allocated metadata to snapshot status
Add number of sectors used by metadata to the end of the snapshot's status
line.

Renamed dm_exception_store_type's 'fraction_full' to 'usage'.  Renamed
arguments to be clearer about what is being returned.  Also added
'metadata_sectors'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:11 +00:00
Jon Brassow
3510cb94ff dm snapshot: rename exception functions
Rename exception functions.  Preparing to pull them out of
dm-snap.c for broader use.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:11 +00:00
Jon Brassow
191437a53c dm snapshot: rename exception_table to dm_exception_table
Rename exception_table for broader use outside dm-snap.c

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:10 +00:00
Jon Brassow
1d4989c858 dm snapshot: rename dm_snap_exception to dm_exception
The exception structure is not necessarily just a snapshot
element (especially after we pull it out of dm-snap.c).

Renaming appropriately.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:10 +00:00
Jon Brassow
d32a6ea65f dm snapshot: consolidate insert exception functions
Consolidate the insert_*exception functions.  'insert_completed_exception'
already contains all the logic to handle 'insert_exception' (via
check for a hash_shift of 0), so remove redundant function.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:09 +00:00
Mikulas Patocka
7e201b3513 dm snapshot: abstract minimum_chunk_size fn
The origin needs to find minimum chunksize of all snapshots.  This logic is
moved to a separate function because it will be used at another place in
the snapshot merge patches.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:08 +00:00
Mikulas Patocka
102c6ddb1d dm snapshot: simplify sector_to_chunk expression
Removed unnecessary 'and' masking: The right shift discards the lower
bits so there is no need to clear them.

(A later patch needs this change to support a 32-bit chunk_mask.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:08 +00:00
Jon Brassow
f5acc83428 dm snapshot: avoid else clause in persistent_read_metadata
Minor code touch-up.  We don't need the 'else'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:07 +00:00
Roel Kluin
a518b86d0b dm ioctl: prefer strlcpy over strncpy
strlcpy() will always null terminate the string.

    The code should already guarantee this as the last bytes are already
    NULs and the string lengths were restricted before being stored in
    hc.  Removing the '-1' becomes necessary so strlcpy() doesn't
    lose the last character of a maximum-length string.
	- agk

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:07 +00:00
Mikulas Patocka
5339fc2d47 dm raid1: explicitly initialise bio_lists
Explicitly initialize bio lists instead of relying on kzalloc.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:06 +00:00
Mikulas Patocka
929be8fcb4 dm raid1: hold all write bios when leg fails
Hold all write bios when leg fails and errors are handled

When using a userspace daemon such as dmeventd to handle errors, we must
delay completing  bios until it has done its job.
This patch prevents the following race:
  - primary leg fails
  - write "1" fail, the write is held, secondary leg is set default
  - write "2" goes straight to the secondary leg

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:06 +00:00
Mikulas Patocka
60f355ead3 dm raid1: hold write bios when errors are handled
Hold all write bios when errors are handled.

Previously the failures list was used only when handling errors with
a userspace daemon such as dmeventd.  Now, it is always used for all bios.
The regions where some writes failed must be marked as nosync. This can only
be done in process context (i.e. in raid1 workqueue), not in the
write_callback function.

Previously the write would succeed if writing to at least one leg
succeeded.  This is wrong because data from the failed leg may be
replicated to the correct leg.  Now, if using a userspace daemon, the
write with some failures will be held until the daemon has done its job
and reconfigured the array.  If not using a daemon, the write still
succeeds if at least one leg succeeds. This is bad, but it is consistent
with current behavior.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:05 +00:00
Mikulas Patocka
c58098be97 dm raid1: remove bio_endio from dm_rh_mark_nosync
Move bio completion out of dm_rh_mark_nosync in preparation for the
next patch.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:05 +00:00
Mikulas Patocka
87968ddd2f dm raid1: abstract get_valid_mirror function
Move the logic to get a valid mirror leg into a function for re-use
in a later patch.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:04 +00:00
Mikulas Patocka
0f398a8403 dm raid1: use hold framework in do_failures
Use the hold framework in do_failures.

This patch doesn't change the bio processing logic, it just simplifies
failure handling and avoids periodically polling the failures list.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:04 +00:00
Mikulas Patocka
0478850768 dm raid1: add framework to hold bios during suspend
Add framework to delay bios until a suspend and then resubmit them with
either DM_ENDIO_REQUEUE (if the suspend was noflush) or complete them
with -EIO.  I/O barrier support will use this.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Takahiro Yasui <tyasui@redhat.com>
Tested-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:03 +00:00
Mikulas Patocka
64b30c46e8 dm raid1: report flush errors separately in status
Report flush errors as 'F' instead of 'D' for log and mirror devices.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:02 +00:00
Mikulas Patocka
c0da3748b9 dm raid1: implement mirror_flush
Implement flush callee. It uses dm_io to send zero-size barrier synchronously
and concurrently to all the mirror legs.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:02 +00:00
Mikulas Patocka
076010e2e6 dm log: use flush callback fn
Call the flush callback from the log.

If flush failed, we have no alternative but to mark the whole log as dirty.
Also we set the variable flush_failed to prevent any bits ever being marked as
clean again.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:01 +00:00
Mikulas Patocka
87a8f240e9 dm log: add flush callback fn
Introduce a callback pointer from the log to dm-raid1 layer.

Before some region is set as "in-sync", we need to flush hardware cache on
all the disks. But the log module doesn't have access to the mirror_set
structure. So it will use this callback.

So far the callback is unused, it will be used in further patches.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:01 +00:00
Mikulas Patocka
5adc78d0d2 dm log: introduce flush_failed variable
Introduce "flush failed" variable.  When a flush before clearing a bit
in the log fails, we don't know anything about which which regions are
in-sync and which not.

So we need to set all regions as not-in-sync and set the variable
"flush_failed" to prevent setting the in-sync bit in the future.

A target reload is the only way to get out of this situation.

The variable will be set in following patches.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:00 +00:00
Mikulas Patocka
20a34a8ecc dm log: add flush_header function
Introduce flush_header and use it to flush the log device.

Note that we don't have to flush if all the regions transition
from "dirty" to "clean" state.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:52:00 +00:00
Mikulas Patocka
b09acf1aa7 dm raid1: split touched state into two
Split the variable "touched" into two, "touched_dirtied" and
"touched_cleaned", set when some region was dirtied or cleaned.

This will be used to optimize flushes.

After a transition from "dirty" to "clean" state we don't have flush hardware
cache on the log device. After a transition from "clean" to "dirty" the cache
must be flushed.

Before a transition from "clean" to "dirty" state we don't have to flush all
the raid legs. Before a transition from "dirty" to "clean" we must flush all
the legs to make sure that they are really in sync.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:59 +00:00
Mikulas Patocka
4184153f9e dm raid1: support flush
Flush support for dm-raid1.

When it receives an empty barrier, submit it to all the devices via dm-io.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:59 +00:00
Mikulas Patocka
f1e5398746 dm io: remove extra bi_io_vec region hack
Remove the hack where we allocate an extra bi_io_vec to store additional
private data.  This hack prevents us from supporting barriers in
dm-raid1 without first making another little block layer change.
Instead of doing that, this patch eliminates the bi_io_vec abuse by
storing the region number directly in the low bits of bi_private.

We need to store two things for each bio, the pointer to the main io
structure and, if parallel writes were requested, an index indicating
which of these writes this bio belongs to.  There can be at most
BITS_PER_LONG regions - 32 or 64.

The index (region number) was stored in the last (hidden) bio vector and
the pointer to struct io was stored in bi_private.

This patch now aligns "struct io" on BITS_PER_LONG bytes and stores the
region number in the low BITS_PER_LONG bits of bi_private.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:58 +00:00
Mikulas Patocka
952b355760 dm io: use slab for struct io
Allocate "struct io" from a slab.

This patch changes dm-io, so that "struct io" is allocated from a slab cache.
It used to be allocated with kmalloc. Allocating from a slab will be needed
for the next patch, because it requires a special alignment of "struct io"
and kmalloc cannot meet this alignment.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:57 +00:00
Milan Broz
542da31766 dm crypt: make wipe message also wipe essiv key
The "wipe key" message is used to wipe the volume key from memory
temporarily, for example when suspending to RAM.

But the initialisation vector in ESSIV mode is calculated from the
hashed volume key, so the wipe message should wipe this IV key too and
reinitialise it when the volume key is reinstated.

This patch adds an IV wipe method called from a wipe message callback.
ESSIV is then reinitialised using the init function added by the
last patch.

Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:57 +00:00
Milan Broz
b95bf2d3d5 dm crypt: separate essiv allocation from initialisation
This patch separates the construction of IV from its initialisation.
(For ESSIV it is a hash calculation based on volume key.)

Constructor code now preallocates hash tfm and salt array
and saves it in a private IV structure.

The next patch requires this to reinitialise the wiped IV
without reallocating memory when resuming a suspended device.

Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:56 +00:00
Milan Broz
5861f1be00 dm crypt: restructure essiv error path
Use kzfree for salt deallocation because it is derived from the volume
key.  Use a common error path in ESSIV constructor.

Required by a later patch which fixes the way key material is wiped
from memory.

Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:56 +00:00
Milan Broz
6047359277 dm crypt: move private iv fields to structs
Define private structures for IV so it's easy to add further attributes
in a following patch which fixes the way key material is wiped from
memory.  Also move ESSIV destructor and remove unnecessary 'status'
operation.

There are no functional changes in this patch.

Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:55 +00:00
Milan Broz
0b4309581b dm crypt: make wipe message also wipe tfm key
The "wipe key" message is used to wipe a volume key from memory
temporarily, for example when suspending to RAM.

There are two instances of the key in memory (inside crypto tfm)
but only one got wiped.  This patch wipes them both.

Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:55 +00:00
Mikulas Patocka
8e87b9b81b dm snapshot: cope with chunk size larger than origin
Under some special conditions the snapshot hash_size is calculated as zero.
This patch instead sets a minimum value of 64, the same as for the
pending exception table.

rounddown_pow_of_two(0) is an undefined operation (it expands to shift
by -1).  init_exception_table with an argument of 0 would fail with -ENOMEM.

The way to trigger the problem is to create a snapshot with a chunk size
that is larger than the origin device.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:54 +00:00
Mikulas Patocka
94e76572b5 dm snapshot: only take lock for statustype info not table
Take snapshot lock only for STATUSTYPE_INFO, not STATUSTYPE_TABLE.

Commit 4c6fff445d
(dm-snapshot-lock-snapshot-while-supplying-status.patch)
introduced this use of the lock, but userspace applications using
libdevmapper have been found to request STATUSTYPE_TABLE while the device
is suspended and the lock is already held, leading to deadlock.  Since
the lock is not necessary in this case, don't try to take it.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:53 +00:00
Milan Broz
d2bb7df8ca dm: sysfs add empty release function to avoid debug warning
This patch just removes an unnecessary warning:
 kobject: 'dm': does not have a release() function,
 it is broken and must be fixed.

The kobject is embedded in mapped device struct, so
code does not need to release memory explicitly here.

Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:53 +00:00
Julia Lawall
613978f871 dm exception store: free tmp_store on persistent flag error
Error handling code following a kmalloc should free the allocated data.

Cc: stable@kernel.org
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:52 +00:00
Mikulas Patocka
6076905b5e dm: avoid _hash_lock deadlock
Fix a reported deadlock if there are still unprocessed multipath events
on a device that is being removed.

_hash_lock is held during dev_remove while trying to send the
outstanding events.  Sending the events requests the _hash_lock
again in dm_copy_name_and_uuid.

This patch introduces a separate lock around regions that modify the
link to the hash table (dm_set_mdptr) or the name or uuid so that
dm_copy_name_and_uuid no longer needs _hash_lock.

Additionally, dm_copy_name_and_uuid can only be called if md exists
so we can drop the dm_get() and dm_put() which can lead to a BUG()
while md is being freed.

The deadlock:
 #0 [ffff8106298dfb48] schedule at ffffffff80063035
 #1 [ffff8106298dfc20] __down_read at ffffffff8006475d
 #2 [ffff8106298dfc60] dm_copy_name_and_uuid at ffffffff8824f740
 #3 [ffff8106298dfc90] dm_send_uevents at ffffffff88252685
 #4 [ffff8106298dfcd0] event_callback at ffffffff8824c678
 #5 [ffff8106298dfd00] dm_table_event at ffffffff8824dd01
 #6 [ffff8106298dfd10] __hash_remove at ffffffff882507ad
 #7 [ffff8106298dfd30] dev_remove at ffffffff88250865
 #8 [ffff8106298dfd60] ctl_ioctl at ffffffff88250d80
 #9 [ffff8106298dfee0] do_ioctl at ffffffff800418c4
#10 [ffff8106298dff00] vfs_ioctl at ffffffff8002fab9
#11 [ffff8106298dff40] sys_ioctl at ffffffff8004bdaf
#12 [ffff8106298dff80] tracesys at ffffffff8005d28d (via system_call)

Cc: stable@kernel.org
Reported-by: guy keren <choo@actcom.co.il>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-12-10 23:51:52 +00:00
Linus Torvalds
4ef58d4e2a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits)
  tree-wide: fix misspelling of "definition" in comments
  reiserfs: fix misspelling of "journaled"
  doc: Fix a typo in slub.txt.
  inotify: remove superfluous return code check
  hdlc: spelling fix in find_pvc() comment
  doc: fix regulator docs cut-and-pasteism
  mtd: Fix comment in Kconfig
  doc: Fix IRQ chip docs
  tree-wide: fix assorted typos all over the place
  drivers/ata/libata-sff.c: comment spelling fixes
  fix typos/grammos in Documentation/edac.txt
  sysctl: add missing comments
  fs/debugfs/inode.c: fix comment typos
  sgivwfb: Make use of ARRAY_SIZE.
  sky2: fix sky2_link_down copy/paste comment error
  tree-wide: fix typos "couter" -> "counter"
  tree-wide: fix typos "offest" -> "offset"
  fix kerneldoc for set_irq_msi()
  spidev: fix double "of of" in comment
  comment typo fix: sybsystem -> subsystem
  ...
2009-12-09 19:43:33 -08:00
Linus Torvalds
382f51fe2f Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (222 commits)
  [SCSI] zfcp: Remove flag ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP
  [SCSI] zfcp: Activate fc4s attributes for zfcp in FC transport class
  [SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED
  [SCSI] zfcp: Update FSF error reporting
  [SCSI] zfcp: Improve ELS ADISC handling
  [SCSI] zfcp: Simplify handling of ct and els requests
  [SCSI] zfcp: Remove ZFCP_DID_MASK
  [SCSI] zfcp: Move WKA port to zfcp FC code
  [SCSI] zfcp: Use common code definitions for FC CT structs
  [SCSI] zfcp: Use common code definitions for FC ELS structs
  [SCSI] zfcp: Update FCP protocol related code
  [SCSI] zfcp: Dont fail SCSI commands when transitioning to blocked fc_rport
  [SCSI] zfcp: Assign scheduled work to driver queue
  [SCSI] zfcp: Remove STATUS_COMMON_REMOVE flag as it is not required anymore
  [SCSI] zfcp: Implement module unloading
  [SCSI] zfcp: Merge trace code for fsf requests in one function
  [SCSI] zfcp: Access ports and units with container_of in sysfs code
  [SCSI] zfcp: Remove suspend callback
  [SCSI] zfcp: Remove global config_mutex
  [SCSI] zfcp: Replace local reference counting with common kref
  ...
2009-12-09 19:42:25 -08:00
Linus Torvalds
1557d33007 Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6: (43 commits)
  security/tomoyo: Remove now unnecessary handling of security_sysctl.
  security/tomoyo: Add a special case to handle accesses through the internal proc mount.
  sysctl: Drop & in front of every proc_handler.
  sysctl: Remove CTL_NONE and CTL_UNNUMBERED
  sysctl: kill dead ctl_handler definitions.
  sysctl: Remove the last of the generic binary sysctl support
  sysctl net: Remove unused binary sysctl code
  sysctl security/tomoyo: Don't look at ctl_name
  sysctl arm: Remove binary sysctl support
  sysctl x86: Remove dead binary sysctl support
  sysctl sh: Remove dead binary sysctl support
  sysctl powerpc: Remove dead binary sysctl support
  sysctl ia64: Remove dead binary sysctl support
  sysctl s390: Remove dead sysctl binary support
  sysctl frv: Remove dead binary sysctl support
  sysctl mips/lasat: Remove dead binary sysctl support
  sysctl drivers: Remove dead binary sysctl support
  sysctl crypto: Remove dead binary sysctl support
  sysctl security/keys: Remove dead binary sysctl support
  sysctl kernel: Remove binary sysctl logic
  ...
2009-12-08 07:38:50 -08:00
Jiri Kosina
d014d04386 Merge branch 'for-next' into for-linus
Conflicts:

	kernel/irq/chip.c
2009-12-07 18:36:35 +01:00
Chandra Seetharaman
3ae31f6a7b [SCSI] scsi_dh: Change the scsidh_activate interface to be asynchronous
Make scsi_dh_activate() function asynchronous, by taking in two additional
parameters, one is the callback function and the other is the data to call
the callback function with.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-12-04 12:00:46 -06:00
NeilBrown
d0e260782c md: revert incorrect fix for read error handling in raid1.
commit 4706b349f was a forward port of a fix that was needed
for SLES10.  But in fact it is not needed in mainline because
the earlier commit dd00a99e7a fixes the same problem in a
better way.
Further, this commit introduces a bug in the way it interacts with
the automatic read-error-correction.  If, after a read error is
successfully corrected, the same disk is chosen to re-read - the
re-read won't be attempted but an error will be returned instead.

After reverting that commit, there is the possibility that a
read error on a read-only array (where read errors cannot
be corrected as that requires a write) will repeatedly read the same
device and continue to get an error.
So in the "Array is readonly" case, fail the drive immediately on
a read error.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
2009-12-01 17:30:59 +11:00
Eric W. Biederman
6d4561110a sysctl: Drop & in front of every proc_handler.
For consistency drop & in front of every proc_handler.  Explicity
taking the address is unnecessary and it prevents optimizations
like stubbing the proc_handlers to NULL.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-18 08:37:40 -08:00
Eric W. Biederman
bb9074ff58 Merge commit 'v2.6.32-rc7'
Resolve the conflict between v2.6.32-rc7 where dn_def_dev_handler
gets a small bug fix and the sysctl tree where I am removing all
sysctl strategy routines.
2009-11-17 01:01:34 -08:00
NeilBrown
c148ffdcda md/raid5: Allow dirty-degraded arrays to be assembled when only party is degraded.
Normally is it not safe to allow a raid5 that is both dirty and
degraded to be assembled without explicit request from that admin, as
it can cause hidden data corruption.
This is because 'dirty' means that the parity cannot be trusted, and
'degraded' means that the parity needs to be used.

However, if the device that is missing contains only parity, then
there is no issue and assembly can continue.
This particularly applies when a RAID5 is being converted to a RAID6
and there is an unclean shutdown while the conversion is happening.

So check for whether the degraded space only contains parity, and
in that case, allow the assembly.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-11-13 17:47:00 +11:00
NeilBrown
7ef90146a1 Don't unconditionally set in_sync on newly added device in raid5_reshape
When a reshape finds that it can add spare devices into the array,
those devices might already be 'in_sync' if they are beyond the old
size of the array, or they might not if they are within the array.

The first case happens when we change an N-drive RAID5 to an
N+1-drive RAID5.
The second happens when we convert an N-drive RAID5 to an
N+1-drive RAID6.

So set the flag more carefully.
Also, ->recovery_offset is only meaningful when the flag is clear,
so only set it in that case.

This change needs the preceding two to ensure that the non-in_sync
device doesn't get evicted from the array when it is stopped, in the
case where v0.90 metadata is used.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-11-13 17:40:51 +11:00
NeilBrown
0261cd9f1c md: allow v0.91 metadata to record devices as being active but not in-sync.
This is a combination that didn't really make sense before.
However when a reshape is converting e.g. raid5 -> raid6, the extra
device is not fully in-sync, but is certainly active and contains
important data.
So allow that start to be meaningful and in particular get
the 'recovery_offset' value (which is needed for any non-in-sync
active device) from the reshape_position.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-11-13 17:40:48 +11:00
Eric W. Biederman
894d249115 sysctl drivers: Remove dead binary sysctl support
Now that sys_sysctl is a wrapper around /proc/sys all of
the binary sysctl support elsewhere in the tree is
dead code.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Corey Minyard <minyard@acm.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Neil Brown <neilb@suse.de>
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Acked-by: Clemens Ladisch <clemens@ladisch.de> for drivers/char/hpet.c
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-12 02:04:58 -08:00
NeilBrown
5e8651060c md: factor out updating of 'recovery_offset'.
Each device has its own 'recovery_offset' showing how far
recovery has progressed on the device.
As the only real significance of this is that fact that it can
be stored in the metadata and recovered at restart, and as
only 1.x metadata can do this, we were only updating
'recovery_offset' to 'curr_resync_completed' when updating
v1.x metadata.
But this is wrong, and we will shortly make limited use of this
field in v0.90 metadata.

So move the update into common code.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-11-12 12:08:04 +11:00
Dirk Hohndel
06fe9fb418 tree-wide: fix a very frequent spelling mistake
something-bility is spelled as something-blity
so a grep for 'blit' would find these lines

this is so trivial that I didn't split it by subsystem / copy
additional maintainers - all changes are to comments
The only purpose is to get fewer false positives when grepping
around the kernel sources.

Signed-off-by: Dirk Hohndel <hohndel@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-09 09:40:54 +01:00
NeilBrown
8dee721146 md/raid5: make sure curr_sync_completes is uptodate when reshape starts
This value is visible through sysfs and is used by mdadm
when it manages a reshape (backing up data that is about to be
rearranged).  So it is important that it is always correct.
Current it does not get updated properly when a reshape
starts which can cause problems when assembling an array
that is in the middle of being reshaped.

This is suitable for 2.6.31.y stable kernels.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-11-06 14:59:29 +11:00
NeilBrown
24395a85d8 md: don't clear endpoint for resync when resync is interrupted.
If a 'sync_max' has been set (via sysfs), it is wrong to clear it
until a resync (or reshape or recovery ...) actually reached that
point.
So if a resync is interrupted (e.g. by device failure),
leave 'resync_max' unchanged.

This is particularly important for 'reshape' operations that do not
change the size of the array.  For such operations mdadm needs to
monitor the reshape taking rolling backups of the section being
reshaped.  If resync_max gets cleared, the reshape can get ahead of
mdadm and then the backups that mdadm creates are useless.

This is suitable for 2.6.31.y stable kernels.
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-11-06 14:59:27 +11:00
Linus Torvalds
bf699c9bac Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  async_tx: fix asynchronous raid6 recovery for ddf layouts
  async_pq: rename scribble page
  async_pq: kill a stray dma_map() call and other cleanups
  md/raid6: kill a gcc-4.0.1 'uninitialized variable' warning
  raid6/async_tx: handle holes in block list in async_syndrome_val
  md/async: don't pass a memory pointer as a page pointer.
  md: Fix handling of raid5 array which is being reshaped to fewer devices.
  md: fix problems with RAID6 calculations for DDF.
  md/raid456: downlevel multicore operations to raid_run_ops
  md: drivers/md/unroll.pl replaced with awk analog
  md: remove clumsy usage of do_sync_mapping_range from bitmap code
  md: raid1/raid10: handle allocation errors during array setup.
  md/raid5: initialize conf->device_lock earlier
  md/raid1/raid10: add a cond_resched
  Revert "md: do not progress the resync process if the stripe was blocked"
2009-10-31 12:12:19 -07:00
David Woodhouse
e5d84970a5 async_tx: Move ASYNC_RAID6_TEST option to crypto/async_tx/, fix dependencies
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-10-29 16:41:49 +00:00
David Woodhouse
f5e70d0fe3 md: Factor out RAID6 algorithms into lib/
We'll want to use these in btrfs too.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2009-10-29 14:38:47 +00:00
Dan Williams
6629542e79 md/raid6: kill a gcc-4.0.1 'uninitialized variable' warning
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-10-19 18:09:41 -07:00
Mikulas Patocka
c1cc65caa1 dm snapshot: allow chunk size to be less than page size
Allow the snapshot chunk size to be smaller than the page size
The code is now capable of handling this due to some previous
fixes and enhancements.

As the page size varies between computers, prior to this patch,
the chunk size of a snapshot dictated which machines could read it:
Snapshots created on one machine might not be readable on another.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:22 +01:00
Mikulas Patocka
df96eee679 dm snapshot: use unsigned integer chunk size
Use unsigned integer chunk size.

Maximum chunk size is 512kB, there won't ever be need to use 4GB chunk size,
so the number can be 32-bit. This fixes compiler failure on 32-bit systems
with large block devices.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:17 +01:00
Mikulas Patocka
4c6fff445d dm snapshot: lock snapshot while supplying status
This patch locks the snapshot when returning status.  It fixes a race
when it could return an invalid number of free chunks if someone
was simultaneously modifying it.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:16 +01:00
Mikulas Patocka
0e8c4e4e3e dm exception store: fix failed set_chunk_size error path
Properly close the device if failing because of an invalid chunk size.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:16 +01:00
Mikulas Patocka
3f2412dc85 dm snapshot: require non zero chunk size by end of ctr
If we are creating snapshot with memory-stored exception store, fail if
the user didn't specify chunk size. Zero chunk size would probably crash
a lot of places in the rest of snapshot code.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:16 +01:00
Kiyoshi Ueda
f88fb98118 dm: dec_pending needs locking to save error value
Multiple instances of dec_pending() can run concurrently so a lock is
needed when it saves the first error code.

I have never experienced actual problem without locking and just found
this during code inspection while implementing the barrier support
patch for request-based dm.

This patch adds the locking.
I've done compile, boot and basic I/O testings.

Cc: stable@kernel.org
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:15 +01:00
Zdenek Kabelac
03022c54b9 dm: add missing del_gendisk to alloc_dev error path
Add missing del_gendisk() to error path when creation of workqueue fails.
Otherwice there is a resource leak and following warning is shown:

WARNING: at fs/sysfs/dir.c:487 sysfs_add_one+0xc5/0x160()
sysfs: cannot create duplicate filename '/devices/virtual/block/dm-0'

Cc: stable@kernel.org
Signed-off-by: Zdenek Kabelac <zkabelac@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:15 +01:00
Andrew Morton
bca915aae8 dm log: userspace fix incorrect luid cast in userspace_ctr
mips:

drivers/md/dm-log-userspace-base.c: In function `userspace_ctr':
drivers/md/dm-log-userspace-base.c:159: warning: cast from pointer to integer of different size

Cc: stable@kernel.org
Cc: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:15 +01:00
Jonathan Brassow
034a186d29 dm snapshot: free exception store on init failure
While initializing the snapshot module, if we fail to register
the snapshot target then we must back-out the exception store
module initialization.

Cc: stable@kernel.org
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:14 +01:00
Mikulas Patocka
6d45d93ead dm snapshot: sort by chunk size to fix race
Avoid a race causing corruption when snapshots of the same origin have
different chunk sizes by sorting the internal list of snapshots by chunk
size, largest first.
  https://bugzilla.redhat.com/show_bug.cgi?id=182659

For example, let's have two snapshots with different chunk sizes. The
first snapshot (1) has small chunk size and the second snapshot (2) has
large chunk size.  Let's have chunks A, B, C in these snapshots:
snapshot1: ====A====   ====B====
snapshot2: ==========C==========

(Chunk size is a power of 2. Chunks are aligned.)

A write to the origin at a position within A and C comes along. It
triggers reallocation of A, then reallocation of C and links them
together using A as the 'primary' exception.

Then another write to the origin comes along at a position within B and
C.  It creates pending exception for B.  C already has a reallocation in
progress and it already has a primary exception (A), so nothing is done
to it: B and C are not linked.

If the reallocation of B finishes before the reallocation of C, because
there is no link with the pending exception for C it does not know to
wait for it and, the second write is dispatched to the origin and causes
data corruption in the chunk C in snapshot2.

To avoid this situation, we maintain snapshots sorted in descending
order of chunk size.  This leads to a guaranteed ordering on the links
between the pending exceptions and avoids the problem explained above -
both A and B now get linked to C.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-10-16 23:18:14 +01:00
NeilBrown
5dd33c9a4c md/async: don't pass a memory pointer as a page pointer.
md/raid6 passes a list of 'struct page *' to the async_tx routines,
which then either DMA map them for offload, or take the page_address
for CPU based calculations.

For RAID6 we sometime leave 'blanks' in the list of pages.
For CPU based calcs, we want to treat theses as a page of zeros.
For offloaded calculations, we simply don't pass a page to the
hardware.

Currently the 'blanks' are encoded as a pointer to
raid6_empty_zero_page.  This is a 4096 byte memory region, not a
'struct page'.  This is mostly handled correctly but is rather ugly.

So change the code to pass and expect a NULL pointer for the blanks.
When taking page_address of a page, we need to check for a NULL and
in that case use raid6_empty_zero_page.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 16:40:25 +11:00
NeilBrown
5e5e3e78ed md: Fix handling of raid5 array which is being reshaped to fewer devices.
When a raid5 (or raid6) array is being reshaped to have fewer devices,
conf->raid_disks is the latter and hence smaller number of devices.
However sometimes we want to use a number which is the total number of
currently required devices - the larger of the 'old' and 'new' sizes.
Before we implemented reducing the number of devices, this was always
'new' i.e. ->raid_disks.
Now we need max(raid_disks, previous_raid_disks) in those places.

This particularly affects assembling an array that was shutdown while
in the middle of a reshape to fewer devices.

md.c needs a similar fix when interpreting the md metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 16:35:30 +11:00
NeilBrown
e4424fee18 md: fix problems with RAID6 calculations for DDF.
Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 16:27:34 +11:00
Dan Williams
417b8d4ac8 md/raid456: downlevel multicore operations to raid_run_ops
The percpu conversion allowed a straightforward handoff of stripe
processing to the async subsytem that initially showed some modest gains
(+4%).  However, this model is too simplistic and leads to stripes
bouncing between raid5d and the async thread pool for every invocation
of handle_stripe().  As reported by Holger this can fall into a
pathological situation severely impacting throughput (6x performance
loss).

By downleveling the parallelism to raid_run_ops the pathological
stripe_head bouncing is eliminated.  This version still exhibits an
average 11% throughput loss for:

	mdadm --create /dev/md0 /dev/sd[b-q] -n 16 -l 6
	echo 1024 > /sys/block/md0/md/stripe_cache_size
	dd if=/dev/zero of=/dev/md0 bs=1024k count=2048

...but the results are at least stable and can be used as a base for
further multicore experimentation.

Reported-by: Holger Kiehl <Holger.Kiehl@dwd.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 16:25:22 +11:00
Vladimir Dronnikov
dce3a7a42d md: drivers/md/unroll.pl replaced with awk analog
drivers/md/unroll.pl replaced by awk script to drop build-time
dependency on perl

Signed-off-by: Vladimir Dronnikov <dronnikov@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 16:25:19 +11:00
NeilBrown
ae8fa2831b md: remove clumsy usage of do_sync_mapping_range from bitmap code
and replace with vfs_fsync which is much neater (but wasn't exported,
or even in existence at the time the code was written).

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 15:56:01 +11:00
NeilBrown
ed9bfdf1a4 md: raid1/raid10: handle allocation errors during array setup.
Both raid1 and raid10 create a mempool during startup.
If the 'alloc' function for this mempool fails, unplug_slaves
is called.
If that happens when the pool is being initialised, unplug_slaves
will try to use the 'conf' structure that isn't filled in yet, and
badness will happen.

So ensure that unplug_slaves doesn't get called unless we know
that the conf structure if fully initialised.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 15:55:44 +11:00
Dan Williams
f5efd45ae5 md/raid5: initialize conf->device_lock earlier
Deallocating a raid5_conf_t structure requires taking 'device_lock'.
Ensure it is initialized before it is used, i.e. initialize the lock
before attempting any further initializations that might fail.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 15:55:38 +11:00
NeilBrown
1d9d52416c md/raid1/raid10: add a cond_resched
During 'check' of a raid1 or raid10 it is possible for the management
thread to spend a lot of time running 'memcmp' on blocks from
different devices, so make sure the thread has a chance to schedule.
raid5d already has a cond_resched (in process_stripe).

Reported-By: Lee Howard <faxguy@howardsilvan.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 15:55:32 +11:00
NeilBrown
1442577bf6 Revert "md: do not progress the resync process if the stripe was blocked"
This reverts commit df10cfbc4d.

This patch was based on a misunderstanding and risks introducing a busy-wait loop.
So revert it.

Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-10-16 15:55:25 +11:00
Nikanth Karthikesan
316d315bff block: Seperate read and write statistics of in_flight requests v2
Commit a9327cac44 added seperate read
and write statistics of in_flight requests. And exported the number
of read and write requests in progress seperately through sysfs.

But  Corrado Zoccolo <czoccolo@gmail.com> reported getting strange
output from "iostat -kx 2". Global values for service time and
utilization were garbage. For interval values, utilization was always
100%, and service time is higher than normal.

So this was reverted by commit 0f78ab9899

The problem was in part_round_stats_single(), I missed the following:
        if (now == part->stamp)
                return;

-       if (part->in_flight) {
+       if (part_in_flight(part)) {
                __part_stat_add(cpu, part, time_in_queue,
                                part_in_flight(part) * (now - part->stamp));
                __part_stat_add(cpu, part, io_ticks, (now - part->stamp));

With this chunk included, the reported regression gets fixed.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>

--
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-10-06 20:16:55 +02:00
Linus Torvalds
58e57fbd1c Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (41 commits)
  Revert "Seperate read and write statistics of in_flight requests"
  cfq-iosched: don't delay async queue if it hasn't dispatched at all
  block: Topology ioctls
  cfq-iosched: use assigned slice sync value, not default
  cfq-iosched: rename 'desktop' sysfs entry to 'low_latency'
  cfq-iosched: implement slower async initiate and queue ramp up
  cfq-iosched: delay async IO dispatch, if sync IO was just done
  cfq-iosched: add a knob for desktop interactiveness
  Add a tracepoint for block request remapping
  block: allow large discard requests
  block: use normal I/O path for discard requests
  swapfile: avoid NULL pointer dereference in swapon when s_bdev is NULL
  fs/bio.c: move EXPORT* macros to line after function
  Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs
  cciss: fix build when !PROC_FS
  block: Do not clamp max_hw_sectors for stacking devices
  block: Set max_sectors correctly for stacking devices
  cciss: cciss_host_attr_groups should be const
  cciss: Dynamically allocate the drive_info_struct for each logical drive.
  cciss: Add usage_count attribute to each logical drive in /sys
  ...
2009-10-04 12:39:14 -07:00
Jens Axboe
0f78ab9899 Revert "Seperate read and write statistics of in_flight requests"
This reverts commit a9327cac44.

Corrado Zoccolo <czoccolo@gmail.com> reports:

"with 2.6.32-rc1 I started getting the following strange output from
"iostat -kx 2":
Linux 2.6.31bisect (et2) 	04/10/2009 	_i686_	(2 CPU)

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          10,70    0,00    3,16   15,75    0,00   70,38

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
sda              18,22     0,00    0,67    0,01    14,77     0,02
43,94     0,01   10,53 39043915,03 2629219,87
sdb              60,89     9,68   50,79    3,04  1724,43    50,52
65,95     0,70   13,06 488437,47 2629219,87

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           2,72    0,00    0,74    0,00    0,00   96,53

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
sda               0,00     0,00    0,00    0,00     0,00     0,00
0,00     0,00    0,00   0,00 100,00
sdb               0,00     0,00    0,00    0,00     0,00     0,00
0,00     0,00    0,00   0,00 100,00

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           6,68    0,00    0,99    0,00    0,00   92,33

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
sda               0,00     0,00    0,00    0,00     0,00     0,00
0,00     0,00    0,00   0,00 100,00
sdb               0,00     0,00    0,00    0,00     0,00     0,00
0,00     0,00    0,00   0,00 100,00

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           4,40    0,00    0,73    1,47    0,00   93,40

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
sda               0,00     0,00    0,00    0,00     0,00     0,00
0,00     0,00    0,00   0,00 100,00
sdb               0,00     4,00    0,00    3,00     0,00    28,00
18,67     0,06   19,50 333,33 100,00

Global values for service time and utilization are garbage. For
interval values, utilization is always 100%, and service time is
higher than normal.

I bisected it down to:
[a9327cac44] Seperate read and write
statistics of in_flight requests
and verified that reverting just that commit indeed solves the issue
on 2.6.32-rc1."

So until this is debugged, revert the bad commit.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-10-04 21:04:38 +02:00
Philipp Reisner
24836479a1 dm/connector: Only process connector packages from privileged processes
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-02 10:54:10 -07:00
Philipp Reisner
18366b05a0 connector/dm: Fixed a compilation warning
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-02 10:54:04 -07:00
Philipp Reisner
7069331dbe connector: Provide the sender's credentials to the callback
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-02 10:54:01 -07:00
NeilBrown
4b3df5668c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx into for-linus 2009-09-23 18:31:11 +10:00
Dmitry Monakhov
1ef04fefe2 md: raid-1/10: fix RW bits manipulation
Recently Jens has changed bio_rw_flagged() logic by following
commit 1f98a13f62. Now it returns
bool instead of int. This broke raid1/raid10 RW bits manipulation logic.
One of visible result is BUG_ON triggering due to empty barrier
here scsi_lib.c:1108 scsi_setup_fs_cmnd()

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-23 18:20:15 +10:00
NeilBrown
f28f4e2728 md: remove unnecessary memset from multipath.
Recent commit bbba809e96
replaced mempool_create_kzalloc_pool with mempool_create_kmalloc_pool
plus a memset.
This memset is not needed (and we didn't need kzalloc in the first
place).
Ever field of the allocated structure (struct multipath_bh) is
initialised immediately except retry_list, and memset does not
initial a list_head anyway.

To remove the memset.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-23 18:16:31 +10:00
NeilBrown
3fa841d7e7 md: report device as congested when suspended
This should writeback from coming when the device is temporarily
suspended.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-23 18:10:29 +10:00
NeilBrown
0da3c6194e md: Improve name of threads created by md_register_thread
The management thread for raid4,5,6 arrays are all called
mdX_raid5, independent of the actual raid level, which is wrong and
can be confusion.

So change md_register_thread to use the name from the personality
unless no alternate name (like 'resync' or 'reshape') is given.

This is simpler and more correct.

Cc: Jinzc <zhenchengjin@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-23 18:09:45 +10:00
NeilBrown
ee305acef5 md: remove sparse warnings about lock context.
There was a real error here on a failure path where we
incorrectly call rcu_read_unlock.


Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-23 18:06:44 +10:00
NeilBrown
a9f326ebf2 md: remove sparse waring "symbol xxx shadows an earlier one"
Rename some variable and remove some duplicate definitions
to avoid there warnings.  None of them are actual errors.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-09-23 18:06:41 +10:00
Linus Torvalds
342ff1a1b5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
  trivial: fix typo in aic7xxx comment
  trivial: fix comment typo in drivers/ata/pata_hpt37x.c
  trivial: typo in kernel-parameters.txt
  trivial: fix typo in tracing documentation
  trivial: add __init/__exit macros in drivers/gpio/bt8xxgpio.c
  trivial: add __init macro/ fix of __exit macro location in ipmi_poweroff.c
  trivial: remove unnecessary semicolons
  trivial: Fix duplicated word "options" in comment
  trivial: kbuild: remove extraneous blank line after declaration of usage()
  trivial: improve help text for mm debug config options
  trivial: doc: hpfall: accept disk device to unload as argument
  trivial: doc: hpfall: reduce risk that hpfall can do harm
  trivial: SubmittingPatches: Fix reference to renumbered step
  trivial: fix typos "man[ae]g?ment" -> "management"
  trivial: media/video/cx88: add __init/__exit macros to cx88 drivers
  trivial: fix typo in CONFIG_DEBUG_FS in gcov doc
  trivial: fix missing printk space in amd_k7_smp_check
  trivial: fix typo s/ketymap/keymap/ in comment
  trivial: fix typo "to to" in multiple files
  trivial: fix typos in comments s/DGBU/DBGU/
  ...
2009-09-22 07:51:45 -07:00
Sage Weil
bbba809e96 md: avoid use of broken kzalloc mempool
The kzalloc mempool does not re-zero items that have been used and then
returned to the pool.  Manually zero the allocated multipath_bh instead.

Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:35 -07:00
Alexey Dobriyan
83d5cde47d const: make block_device_operations const
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:25 -07:00
Anand Gadiyar
411c940385 trivial: fix typo "for for" in multiple files
trivial: fix typo "for for" in multiple files

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-09-21 15:14:54 +02:00
Kay Sievers
e454cea20b Driver-Core: extend devnode callbacks to provide permissions
This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 12:50:38 -07:00
Dan Williams
6c910a78e4 md/raid6: cleanup ops_run_compute6_2
Neil says:
	"It is correct as it stands, but the fact that every branch in
	 the 'if' part ends with a 'return' isn't immediately obvious,
	 so it is clearer if we are explicit about the if / then / else
	 structure."

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-16 12:24:54 -07:00
Dan Williams
2d6e4ecc87 md/raid6: eliminate BUG_ON with side effect
As pointed out by Neil it should be possible to build a driver with all
BUG_ON statements deleted.  It's bad form to have a BUG_ON with a side
effect.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-16 12:11:54 -07:00
Linus Torvalds
355bbd8cb8 Merge branch 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block: (29 commits)
  block: use blkdev_issue_discard in blk_ioctl_discard
  Make DISCARD_BARRIER and DISCARD_NOBARRIER writes instead of reads
  block: don't assume device has a request list backing in nr_requests store
  block: Optimal I/O limit wrapper
  cfq: choose a new next_req when a request is dispatched
  Seperate read and write statistics of in_flight requests
  aoe: end barrier bios with EOPNOTSUPP
  block: trace bio queueing trial only when it occurs
  block: enable rq CPU completion affinity by default
  cfq: fix the log message after dispatched a request
  block: use printk_once
  cciss: memory leak in cciss_init_one()
  splice: update mtime and atime on files
  block: make blk_iopoll_prep_sched() follow normal 0/1 return convention
  cfq-iosched: get rid of must_alloc flag
  block: use interrupts disabled version of raise_softirq_irqoff()
  block: fix comment in blk-iopoll.c
  block: adjust default budget for blk-iopoll
  block: fix long lines in block/blk-iopoll.c
  block: add blk-iopoll, a NAPI like approach for block devices
  ...
2009-09-14 17:55:15 -07:00
Linus Torvalds
39695224bd Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (209 commits)
  [SCSI] fix oops during scsi scanning
  [SCSI] libsrp: fix memory leak in srp_ring_free()
  [SCSI] libiscsi, bnx2i: make bound ep check common
  [SCSI] libiscsi: add completion function for drivers that do not need pdu processing
  [SCSI] scsi_dh_rdac: changes for rdac debug logging
  [SCSI] scsi_dh_rdac: changes to collect the rdac debug information during the initialization
  [SCSI] scsi_dh_rdac: move the init code from rdac_activate to rdac_bus_attach
  [SCSI] sg: fix oops in the error path in sg_build_indirect()
  [SCSI] mptsas : Bump version to 3.04.12
  [SCSI] mptsas : FW event thread and scsi mid layer deadlock in SYNCHRONIZE CACHE command
  [SCSI] mptsas : Send DID_NO_CONNECT for pending IOs of removed device
  [SCSI] mptsas : PAE Kernel more than 4 GB kernel panic
  [SCSI] mptsas : NULL pointer on big endian systems causing Expander not to tear off
  [SCSI] mptsas : Sanity check for phyinfo is added
  [SCSI] scsi_dh_rdac: Add support for Sun StorageTek ST2500, ST2510 and ST2530
  [SCSI] pmcraid: PMC-Sierra MaxRAID driver to support 6Gb/s SAS RAID controller
  [SCSI] qla2xxx: Update version number to 8.03.01-k6.
  [SCSI] qla2xxx: Properly delete rports attached to a vport.
  [SCSI] qla2xxx: Correct various NPIV issues.
  [SCSI] qla2xxx: Correct qla2x00_eh_wait_on_command() to wait correctly.
  ...
2009-09-14 17:53:36 -07:00
Martin K. Petersen
3c5820c743 block: Optimal I/O limit wrapper
Implement blk_limits_io_opt() and make blk_queue_io_opt() a wrapper
around it. DM needs this to avoid poking at the queue_limits directly.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-14 08:24:52 +02:00
Nikanth Karthikesan
a9327cac44 Seperate read and write statistics of in_flight requests
Currently, there is a single in_flight counter measuring the number of
requests in the request_queue. But some monitoring tools would like to
know how many read requests and write requests are in progress. Split the
current in_flight counter into two seperate counters for read and write.

This information is exported as a sysfs attribute, as changing the
currently available stat files would break the existing tools.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-14 08:24:52 +02:00
Jens Axboe
1f98a13f62 bio: first step in sanitizing the bio->bi_rw flag testing
Get rid of any functions that test for these bits and make callers
use bio_rw_flagged() directly. Then it is at least directly apparent
what variable and flag they check.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-11 14:33:31 +02:00
Geert Uytterhoeven
0d03d59d9b md: Fix "strchr" [drivers/md/dm-log-userspace.ko] undefined!
Commit b8313b6da7 ("dm log: remove incorrect
field from userspace table output") added a call to strstr() with a
single-character "needle" string parameter.

Unfortunately some versions of gcc replace such calls to strstr() by calls
to strchr() behind our back.  This causes linking errors if strchr() is
defined as an inline function in <asm/string.h> (e.g. on m68k):

| WARNING: "strchr" [drivers/md/dm-log-userspace.ko] undefined!

Avoid this by explicitly calling strchr() instead.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-10 14:55:01 -07:00
Dan Williams
9134d02bc0 Merge commit 'md/for-linus' into async-tx-next
Conflicts:
	drivers/md/raid5.c
2009-09-08 17:55:54 -07:00
Dan Williams
bbb20089a3 Merge branch 'dmaengine' into async-tx-next
Conflicts:
	crypto/async_tx/async_xor.c
	drivers/dma/ioat/dma_v2.h
	drivers/dma/ioat/pci.c
	drivers/md/raid5.c
2009-09-08 17:55:21 -07:00
Dan Williams
0403e38277 dmaengine: add fence support
Some engines optimize operation by reading ahead in the descriptor chain
such that descriptor2 may start execution before descriptor1 completes.
If descriptor2 depends on the result from descriptor1 then a fence is
required (on descriptor2) to disable this optimization.  The async_tx
api could implicitly identify dependencies via the 'depend_tx'
parameter, but that would constrain cases where the dependency chain
only specifies a completion order rather than a data dependency.  So,
provide an ASYNC_TX_FENCE to explicitly identify data dependencies.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-09-08 17:42:50 -07:00
Dan Williams
f9dd213437 Merge branch 'md-raid6-accel' into ioat3.2
Conflicts:
	include/linux/dmaengine.h
2009-09-08 17:42:29 -07:00
Mikulas Patocka
ae0b7448e9 dm snapshot: fix on disk chunk size validation
Fix some problems seen in the chunk size processing when activating a
pre-existing snapshot.

For a new snapshot, the chunk size can either be supplied by the creator
or a default value can be used.  For an existing snapshot, the
chunk size in the snapshot header on disk should always be used.

If someone attempts to load an existing snapshot and has the 'default
chunk size' option set, the kernel uses its default value even when it
is incorrect for the snapshot being loaded.  This patch ensures the
correct on-disk value is always used.

Secondly, when the code does use the chunk size stored on the disk it is
prudent to revalidate it, so the code can exit cleanly if it got
corrupted as happened in
https://bugzilla.redhat.com/show_bug.cgi?id=461506 .

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:43 +01:00
Mikulas Patocka
2defcc3fb4 dm exception store: split set_chunk_size
Break the function set_chunk_size to two functions in preparation for
the fix in the following patch.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:41 +01:00
Mikulas Patocka
61578dcd3f dm snapshot: fix header corruption race on invalidation
If a persistent snapshot fills up, a race can corrupt the on-disk header
which causes a crash on any future attempt to activate the snapshot
(typically while booting).  This patch fixes the race.

When the snapshot overflows, __invalidate_snapshot is called, which calls
snapshot store method drop_snapshot. It goes to persistent_drop_snapshot that
calls write_header. write_header constructs the new header in the "area"
location.

Concurrently, an existing kcopyd job may finish, call copy_callback
and commit_exception method, that goes to persistent_commit_exception.
persistent_commit_exception doesn't do locking, relying on the fact that
callbacks are single-threaded, but it can race with snapshot invalidation and
overwrite the header that is just being written while the snapshot is being
invalidated.

The result of this race is a corrupted header being written that can
lead to a crash on further reactivation (if chunk_size is zero in the
corrupted header).

The fix is to use separate memory areas for each.

See the bug: https://bugzilla.redhat.com/show_bug.cgi?id=461506

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:39 +01:00
Mikulas Patocka
02d2fd31de dm snapshot: refactor zero_disk_area to use chunk_io
Refactor chunk_io to prepare for the fix in the following patch.

Pass an area pointer to chunk_io and simplify zero_disk_area to use
chunk_io.  No functional change.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:37 +01:00
Jonathan Brassow
7ec23d5094 dm log: userspace add luid to distinguish between concurrent log instances
Device-mapper userspace logs (like the clustered log) are
identified by a universally unique identifier (UUID).  This
identifier is used to associate requests from the kernel to
a specific log in userspace.  The UUID must be unique everywhere,
since multiple machines may use this identifier when communicating
about a particular log, as is the case for cluster logs.

Sometimes, device-mapper/LVM may re-use a UUID.  This is the
case during pvmoves, when moving from one segment of an LV
to another, or when resizing a mirror, etc.  In these cases,
a new log is created with the same UUID and loaded in the
"inactive" slot.  When a device-mapper "resume" is issued,
the "live" table is deactivated and the new "inactive" table
becomes "live".  (The "inactive" table can also be removed
via a device-mapper 'clear' command.)

The above two issues were colliding.  More than one log was being
created with the same UUID, and there was no way to distinguish
between them.  So, sometimes the wrong log would be swapped
out during the exchange.

The solution is to create a locally unique identifier,
'luid', to go along with the UUID.  This new identifier is used
to determine exactly which log is being referenced by the kernel
when the log exchange is made.  The identifier is not
universally safe, but it does not need to be, since
create/destroy/suspend/resume operations are bound to a specific
machine; and these are the operations that make up the exchange.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:34 +01:00
Jonathan Brassow
d2b698644c dm raid1: do not allow log_failure variable to unset after being set
This patch fixes a bug which was triggering a case where the primary leg
could not be changed on failure even when the mirror was in-sync.

The case involves the failure of the primary device along with
the transient failure of the log device.  The problem is that
bios can be put on the 'failures' list (due to log failure)
before 'fail_mirror' is called due to the primary device failure.
Normally, this is fine, but if the log device failure is transient,
a subsequent iteration of the work thread, 'do_mirror', will
reset 'log_failure'.  The 'do_failures' function then resets
the 'in_sync' variable when processing bios on the failures list.
The 'in_sync' variable is what is used to determine if the
primary device can be switched in the event of a failure.  Since
this has been reset, the primary device is incorrectly assumed
to be not switchable.

The case has been seen in the cluster mirror context, where one
machine realizes the log device is dead before the other machines.
As the responsibilities of the server migrate from one node to
another (because the mirror is being reconfigured due to the failure),
the new server may think for a moment that the log device is fine -
thus resetting the 'log_failure' variable.

In any case, it is inappropiate for us to reset the 'log_failure'
variable.  The above bug simply illustrates that it can actually
hurt us.

Cc: stable@kernel.org
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:32 +01:00
Jonathan Brassow
b8313b6da7 dm log: remove incorrect field from userspace table output
The output of 'dmsetup table' includes an internal field that should not
be there.  This patch removes it.  To make the fix simpler, we first
reorder a constructor argument

The 'device size' argument is generated internally.  Currently it is
placed as the last space-separated word of the constructor string.
However, we need to use a version of the string without this word, so we
move it to the beginning instead so it is trivial to skip past it.

We keep a copy of the arguments passed to userspace for creating a log,
just in case we need to resend them.  These are the same arguments that
are desired in the STATUSTYPE_TABLE request, except for one.  When
creating the userspace log, the userspace daemon must know the size of
the mirror, so that is added to the arguments given in the constructor
table.  We were printing this extra argument out as well, which is a
mistake.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:30 +01:00
Jonathan Brassow
4142a96917 dm log: fix userspace status output
Fix 'dmsetup table' output.

There is a missing ' ' at the end of the string causing two
words to run together.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:28 +01:00
Mike Snitzer
40bea43127 dm stripe: expose correct io hints
Set sensible I/O hints for striped DM devices in the topology
infrastructure added for 2.6.31 for userspace tools to
obtain via sysfs.

Add .io_hints to 'struct target_type' to allow the I/O hints portion
(io_min and io_opt) of the 'struct queue_limits' to be set by each
target and implement this for dm-stripe.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:25 +01:00
Mike Snitzer
a963a95622 dm table: add more context to terse warning messages
A couple of recent warning messages make it difficult for the reader to
determine exactly what is wrong.  This patch adds more information to
those messages.

The messages were added by these commits:
  5dea271b6d ("dm table: pass correct dev area size
to device_area_is_valid")
  ea9df47cc9 ("dm table: fix blk_stack_limits arg
to use bytes not sectors")

The patch also corrects references to logical_block_size in printk format
strings from %hu to %u.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:24 +01:00
Mikulas Patocka
f6a1ed1086 dm table: fix queue_limit checking device iterator
The logic to check for valid device areas is inverted relative to proper
use with iterate_devices.

The iterate_devices method calls its callback for every underlying
device in the target.  If any callback returns non-zero, iterate_devices
exits immediately.  But the callback device_area_is_valid() returns 0 on
error and 1 on success.  The overall effect without is that an error is
issued only if every device is invalid.

This patch renames device_area_is_valid to device_area_is_invalid and
inverts the logic so that one invalid device is sufficient to raise
an error.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:22 +01:00
Mike Snitzer
8811f46c1f dm snapshot: implement iterate devices
Implement the .iterate_devices for the origin and snapshot targets.
dm-snapshot's lack of .iterate_devices resulted in the inability to
properly establish queue_limits for both targets.

With 4K sector drives: an unfortunate side-effect of not establishing
proper limits in either targets' DM device was that IO to the devices
would fail even though both had been created without error.

Commit af4874e03e ("dm target:s introduce
iterate devices fn") in 2.6.31-rc1 should have implemented .iterate_devices
for dm-snap.c's origin and snapshot targets.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:19 +01:00
Kiyoshi Ueda
a77e28c7e1 dm multipath: fix oops when request based io fails when no paths
The patch posted at http://marc.info/?l=dm-devel&m=124539787228784&w=2
which was merged into cec47e3d4a ("dm:
prepare for request based option") introduced a regression in
request-based dm.

If map_request() calls dm_kill_unmapped_request() to complete a cloned
bio without dispatching it, clone->bio is still set when
dm_end_request() is called and the BUG_ON(clone->bio) is incorrect.

The patch fixes this bug by freeing bio in dm_end_request() if the clone
has bio.  I've redone my tests to cover all I/O paths and confirmed
there's no other regression.

Here is the oops I hit in request-based dm when I do I/O to a multipath
device which doesn't have any active path nor queue_if_no_path setting:

------------[ cut here ]------------
kernel BUG at /root/2.6.31-rc4.rqdm/drivers/md/dm.c:828!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/devices/system/cpu/cpu3/cache/index2/shared_cpu_map
CPU 1
Modules linked in: autofs4 sunrpc cpufreq_ondemand acpi_cpufreq dm_mirror dm_region_hash dm_log dm_service_time dm_multipath scsi_dh dm_mod video output sbs sbshc battery ac sg sr_mod e1000e button cdrom serio_raw rtc_cmos rtc_core rtc_lib piix lpfc scsi_transport_fc ata_piix libata megaraid_sas sd_mod scsi_mod crc_t10dif ext3 jbd uhci_hcd ohci_hcd ehci_hcd [last unloaded: microcode]
Pid: 7, comm: ksoftirqd/1 Not tainted 2.6.31-rc4.rqdm #1 Express5800/120Lj [N8100-1417]
RIP: 0010:[<ffffffffa023629d>]  [<ffffffffa023629d>] dm_softirq_done+0xbd/0x100 [dm_mod]
RSP: 0018:ffff8800280a1f08  EFLAGS: 00010282
RAX: ffffffffa02544e0 RBX: ffff8802aa1111d0 RCX: ffff8802aa1111e0
RDX: ffff8802ab913e70 RSI: 0000000000000000 RDI: ffff8802ab913e70
RBP: ffff8800280a1f28 R08: ffffc90005457040 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffffb
R13: ffff8802ab913e88 R14: ffff8802ab9c1438 R15: 0000000000000100
FS:  0000000000000000(0000) GS:ffff88002809e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000003d54a98640 CR3: 000000029f0a1000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process ksoftirqd/1 (pid: 7, threadinfo ffff8802ae50e000, task ffff8802ae4f8040)
Stack:
 ffff8800280a1f38 0000000000000020 ffffffff814f30a0 0000000000000004
<0> ffff8800280a1f58 ffffffff8116b245 ffff8800280a1f38 ffff8800280a1f38
<0> ffff8800280a1f58 0000000000000001 ffff8800280a1fa8 ffffffff810477bc
Call Trace:
 <IRQ>
 [<ffffffff8116b245>] blk_done_softirq+0x75/0x90
 [<ffffffff810477bc>] __do_softirq+0xcc/0x210
 [<ffffffff81047170>] ? ksoftirqd+0x0/0x110
 [<ffffffff8100ce7c>] call_softirq+0x1c/0x50
 <EOI>
 [<ffffffff8100e785>] do_softirq+0x65/0xa0
 [<ffffffff81047170>] ? ksoftirqd+0x0/0x110
 [<ffffffff810471e0>] ksoftirqd+0x70/0x110
 [<ffffffff81059559>] kthread+0x99/0xb0
 [<ffffffff8100cd7a>] child_rip+0xa/0x20
 [<ffffffff8100c73c>] ? restore_args+0x0/0x30
 [<ffffffff810594c0>] ? kthread+0x0/0xb0
 [<ffffffff8100cd70>] ? child_rip+0x0/0x20
Code: 44 89 e6 48 89 df e8 23 fb f2 e0 be 01 00 00 00 4c 89 f7 e8 f6 fd ff ff 5b 41 5c 41 5d 41 5e c9 c3 4c 89 ef e8 85 fe ff ff eb ed <0f> 0b eb fe 41 8b 85 dc 00 00 00 48 83 bb 10 01 00 00 00 89 83
RIP  [<ffffffffa023629d>] dm_softirq_done+0xbd/0x100 [dm_mod]
 RSP <ffff8800280a1f08>
---[ end trace 16af0a1d8542da55 ]---

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-09-04 20:40:16 +01:00
Dan Williams
07a3b417dc md/raid456: distribute raid processing over multiple cores
Now that the resources to handle stripe_head operations are allocated
percpu it is possible for raid5d to distribute stripe handling over
multiple cores.  This conversion also adds a call to cond_resched() in
the non-multicore case to prevent one core from getting monopolized for
raid operations.

Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:13:13 -07:00
Yuri Tikhonov
b774ef491b md/raid6: remove synchronous infrastructure
These routines have been replaced by there asynchronous counterparts.

Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:13:13 -07:00
Yuri Tikhonov
6c0069c0ae md/raid6: asynchronous handle_stripe6
1/ Use STRIPE_OP_BIOFILL to offload completion of read requests to
   raid_run_ops
2/ Implement a handler for sh->reconstruct_state similar to the raid5 case
   (adds handling of Q parity)
3/ Prevent handle_parity_checks6 from running concurrently with 'compute'
   operations
4/ Hook up raid_run_ops

Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:13:13 -07:00
Dan Williams
d82dfee0ad md/raid6: asynchronous handle_parity_check6
[ Based on an original patch by Yuri Tikhonov ]

Implement the state machine for handling the RAID-6 parities check and
repair functionality.  Note that the raid6 case does not need to check
for new failures, like raid5, as it will always writeback the correct
disks.  The raid5 case can be updated to check zero_sum_result to avoid
getting confused by new failures rather than retrying the entire check
operation.

Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:13:13 -07:00
Yuri Tikhonov
a9b39a741a md/raid6: asynchronous handle_stripe_dirtying6
In the synchronous implementation of stripe dirtying we processed a
degraded stripe with one call to handle_stripe_dirtying6().  I.e.
compute the missing blocks from the other drives, then copy in the new
data and reconstruct the parities.

In the asynchronous case we do not perform stripe operations directly.
Instead, operations are scheduled with flags to be later serviced by
raid_run_ops.  So, for the degraded case the final reconstruction step
can only be carried out after all blocks have been brought up to date by
being read, or computed.  Like the raid5 case schedule_reconstruction()
sets STRIPE_OP_RECONSTRUCT to request a parity generation pass and
through operation chaining can handle compute and reconstruct in a
single raid_run_ops pass.

[dan.j.williams@intel.com: fixup handle_stripe_dirtying6 gating]
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:13:12 -07:00
Yuri Tikhonov
5599becca4 md/raid6: asynchronous handle_stripe_fill6
Modify handle_stripe_fill6 to work asynchronously by introducing
fetch_block6 as the raid6 analog of fetch_block5 (schedule compute
operations for missing/out-of-sync disks).

[dan.j.williams@intel.com: compute D+Q in one pass]
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:13:12 -07:00
Yuri Tikhonov
c0f7bddbe6 md/raid5,6: common schedule_reconstruction for raid5/6
Extend schedule_reconstruction5 for reuse by the raid6 path.  Add
support for generating Q and BUG() if a request is made to perform
'prexor'.

Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:13:12 -07:00
Dan Williams
ac6b53b6e6 md/raid6: asynchronous raid6 operations
[ Based on an original patch by Yuri Tikhonov ]

The raid_run_ops routine uses the asynchronous offload api and
the stripe_operations member of a stripe_head to carry out xor+pq+copy
operations asynchronously, outside the lock.

The operations performed by RAID-6 are the same as in the RAID-5 case
except for no support of STRIPE_OP_PREXOR operations. All the others
are supported:
STRIPE_OP_BIOFILL
 - copy data into request buffers to satisfy a read request
STRIPE_OP_COMPUTE_BLK
 - generate missing blocks (1 or 2) in the cache from the other blocks
STRIPE_OP_BIODRAIN
 - copy data out of request buffers to satisfy a write request
STRIPE_OP_RECONSTRUCT
 - recalculate parity for new data that has entered the cache
STRIPE_OP_CHECK
 - verify that the parity is correct

The flow is the same as in the RAID-5 case, and reuses some routines, namely:
1/ ops_complete_postxor (renamed to ops_complete_reconstruct)
2/ ops_complete_compute (updated to set up to 2 targets uptodate)
3/ ops_run_check (renamed to ops_run_check_p for xor parity checks)

[neilb@suse.de: fixes to get it to pass mdadm regression suite]
Reviewed-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:13:12 -07:00
Dan Williams
4e7d2c0aef md/raid5: factor out mark_uptodate from ops_complete_compute5
ops_complete_compute5 can be reused in the raid6 path if it is updated to
generically handle a second target.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:13:11 -07:00
Dan Williams
cb3c82992f async_tx: raid6 recovery self test
Port drivers/md/raid6test/test.c to use the async raid6 recovery
routines.  This is meant as a unit test for raid6 acceleration drivers.  In
addition to the 16-drive test case this implements tests for the 4-disk and
5-disk special cases (dma devices can not generically handle less than 2
sources), and adds a test for the D+Q case.

Reviewed-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:09:28 -07:00
Dan Williams
ad283ea4a3 async_tx: add sum check flags
Replace the flat zero_sum_result with a collection of flags to contain
the P (xor) zero-sum result, and the soon to be utilized Q (raid6 reed
solomon syndrome) zero-sum result.  Use the SUM_CHECK_ namespace instead
of DMA_ since these flags will be used on non-dma-zero-sum enabled
platforms.

Reviewed-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:09:26 -07:00
Dan Williams
d6f38f31f3 md/raid5,6: add percpu scribble region for buffer lists
Use percpu memory rather than stack for storing the buffer lists used in
parity calculations.  Include space for dma address conversions and pass
that to async_tx via the async_submit_ctl.scribble pointer.

[ Impact: move memory pressure from stack to heap ]

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:09:26 -07:00
Dan Williams
36d1c6476b md/raid6: move the spare page to a percpu allocation
In preparation for asynchronous handling of raid6 operations move the
spare page to a percpu allocation to allow multiple simultaneous
synchronous raid6 recovery operations.

Make this allocation cpu hotplug aware to maximize allocation
efficiency.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-08-29 19:09:26 -07:00
Chandra Seetharaman
2bfd2e1337 [SCSI] scsi_dh: Use scsi_dh_set_params() in multipath.
Use scsi_dh_set_params() set parameters provided. Save the parameters in
parse_hw_handler() and use it in parse_path().

Reported-by: Eddie Williams <Eddie.Williams@steeleye.com>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Tested-by: Eddie Williams <Eddie.Williams@steeleye.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-08-22 17:52:15 -05:00
Linus Torvalds
435a71d9ef Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  Fix new incorrect error return from do_md_stop.
2009-08-18 13:54:08 -07:00
NeilBrown
80ffb3ccea Fix new incorrect error return from do_md_stop.
Recent commit c8c00a6915
changed the exit paths in do_md_stop and was not quite
careful enough.  There is one path were 'err' now needs
to be cleared but it isn't.
So setting an array to readonly (with mdadm --readonly) will
work, but will incorrectly report and error: ENXIO.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-18 10:35:26 +10:00
Randy Dunlap
894ef820b1 dm-log-userspace: fix printk format warning
drivers/md/dm-log-userspace-transfer.c:110: warning: format '%lu' expects type 'long unsigned int', but argument 4 has type 'size_t'

Previously posted and acked, but apparently lost.
http://lkml.indiana.edu/hypermail/linux/kernel/0906.2/02074.html

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: dm-devel@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-16 08:35:58 -07:00
NeilBrown
4d484a4a7a md: allow upper limit for resync/reshape to be set when array is read-only
Normally we only allow the upper limit for a reshape to be decreased
when the array not performing a sync/recovery/reshape, otherwise there
could be races.  But if an array is part-way through a reshape when it
is assembled the reshape is started immediately leaving no window
to set an upper bound.

If the array is started read-only, the reshape will be suspended until
the array becomes writable, so that provides a window during which it
is perfectly safe to reduce the upper limit of a reshape.

So: allow the upper limit (sync_max) to be reduced even if the reshape
thread is running, as long as the array is still read-only.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 10:41:50 +10:00
NeilBrown
1a67dde0ab md/raid5: Properly remove excess drives after shrinking a raid5/6
We were removing the drives, from the array, but not
removing symlinks from /sys/.... and not marking the device
as having been removed.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 10:41:49 +10:00
NeilBrown
a639755cf8 md/raid5: make sure a reshape restarts at the correct address.
This "if" don't allow for the possibility that the number of devices
doesn't change, and so sector_nr isn't set correctly in that case.
So change '>' to '>='.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 10:13:00 +10:00
NeilBrown
67ac6011db md/raid5: allow new reshape modes to be restarted in the middle.
md/raid5 doesn't allow a reshape to restart if it involves writing
over the same part of disk that it would be reading from.
This happens at the beginning of a reshape that increases the number
of devices, at the end of a reshape that decreases the number of
devices, and continuously for a reshape that does not change the
number of devices.

The current code is correct for the "increase number of devices"
case as the critical section at the start is handled by userspace
performing a backup.

It does not work for reducing the number of devices, or the
no-change case.
For 'reducing', we need to invert the test.  For no-change we cannot
really be sure things will be safe, so simply require the array
to be read-only, which is how the user-space code which carefully
starts such arrays works.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 10:06:24 +10:00
NeilBrown
51d5668cb2 md: never advance 'events' counter by more than 1.
When assembling arrays, md allows two devices to have different event
counts as long as the difference is only '1'.  This is to cope with
a system failure between updating the metadata on two difference
devices.

However there are currently times when we update the event count by
2.  This was done to keep the event count even when the array is clean
and odd when it is dirty, which allows us to avoid writing common
update to spare devices and so allow those spares to go to sleep.

This is bad for the above reason.  So change it to never increase by
two.  This means that the alignment between 'odd/even' and
'clean/dirty' might take a little longer to attain, but that is only a
small cost.  The spares will get a few more updates but that will
still be spared (;-) most updates and can still go to sleep.

Prior to this patch there was a small chance that after a crash an
array would fail to assemble due to the overly large event count
mismatch.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-13 09:54:02 +10:00
NeilBrown
c8c00a6915 Remove deadlock potential in md_open
A recent commit:
  commit 449aad3e25

introduced the possibility of an A-B/B-A deadlock between
bd_mutex and reconfig_mutex.

__blkdev_get holds bd_mutex while calling md_open which takes
   reconfig_mutex,
do_md_run is always called with reconfig_mutex held, and it now
   takes bd_mutex in the call the revalidate_disk.

This potential deadlock was not caught by lockdep due to the
use of mutex_lock_interruptible_nexted which was introduced
by
   commit d63a5a74de
do avoid a warning of an impossible deadlock.

It is quite possible to split reconfig_mutex in to two locks.
One protects the array data structures while it is being
reconfigured, the other ensures that an array is never even partially
open while it is being deactivated.
In particular, the second lock prevents an open from completing
between the time when do_md_stop checks if there are any active opens,
and the time when the array is either set read-only, or when ->pers is
set to NULL.  So we can be certain that no IO is in flight as the
array is being destroyed.

So create a new lock, open_mutex, just to ensure exclusion between
'open' and 'stop'.

This avoids the deadlock and also avoids the lockdep warning mentioned
in commit d63a5a74d

Reported-by: "Mike Snitzer" <snitzer@gmail.com>
Reported-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-10 12:50:52 +10:00
NeilBrown
449aad3e25 md: Use revalidate_disk to effect changes in size of device.
As revalidate_disk calls check_disk_size_change, it will cause
any capacity change of a gendisk to be propagated to the blockdev
inode.  So use that instead of mucking about with locks and
i_size_write.

Also add a call to revalidate_disk in do_md_run and a few other places
where the gendisk capacity is changed.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:58 +10:00
NeilBrown
64bd660b51 md: allow raid5_quiesce to work properly when reshape is happening.
The ->quiesce method is not supposed to stop resync/recovery/reshape,
just normal IO.
But in raid5 we don't have a way to know which stripes are being
used for normal IO and which for resync etc, so we need to wait for
all stripes to be idle to be sure that all writes have completed.

However reshape keeps at least some stripe busy for an extended period
of time, so a call to raid5_quiesce can block for several seconds
needlessly.
So arrange for reshape etc to pause briefly while raid5_quiesce is
trying to quiesce the array so that the active_stripes count can
drop to zero.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:58 +10:00
NeilBrown
e516402c0d md/raid5: set reshape_position correctly when reshape starts.
As the internal reshape_progress counter is the main driver
for reshape, the fact that reshape_position sometimes starts with the
wrong value has minimal effect.  It is visible in sysfs and that
is all.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:57 +10:00
NeilBrown
70471dafe3 md: Handle growth of v1.x metadata correctly.
The v1.x metadata does not have a fixed size and can grow
when devices are added.
If it grows enough to require an extra sector of storage,
we need to update the 'sb_size' to match.

Without this, md can write out an incomplete superblock with a
bad checksum, which will be rejected when trying to re-assemble
the array.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:57 +10:00
NeilBrown
3673f305fa md: avoid array overflow with bad v1.x metadata
We trust the 'desc_nr' field in v1.x metadata enough to use it
as an index in an array.  This isn't really safe.
So range-check the value first.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:56 +10:00
NeilBrown
3a981b03f3 md: when a level change reduces the number of devices, remove the excess.
When an array is changed from RAID6 to RAID5, fewer drives are
needed.  So any device that is made superfluous by the level
conversion must be marked as not-active.
For the RAID6->RAID5 conversion, this will be a drive which only
has 'Q' blocks on it.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:55 +10:00
Andre Noll
ac5e7113e7 md: Push down data integrity code to personalities.
This patch replaces md_integrity_check() by two new public functions:
md_integrity_register() and md_integrity_add_rdev() which are both
personality-independent.

md_integrity_register() is called from the ->run and ->hot_remove
methods of all personalities that support data integrity.  The
function iterates over the component devices of the array and
determines if all active devices are integrity capable and if their
profiles match. If this is the case, the common profile is registered
for the mddev via blk_integrity_register().

The second new function, md_integrity_add_rdev() is called from the
->hot_add_disk methods, i.e. whenever a new device is being added
to a raid array. If the new device does not support data integrity,
or has a profile different from the one already registered, data
integrity for the mddev is disabled.

For raid0 and linear, only the call to md_integrity_register() from
the ->run method is necessary.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-08-03 10:59:47 +10:00
Dan Williams
95fc17aac4 md/raid6: release spare page at ->stop()
Add missing call to safe_put_page from stop() by unifying open coded
raid5_conf_t de-allocation under free_conf().

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-31 12:39:15 +10:00
Mike Snitzer
5dea271b6d dm table: pass correct dev area size to device_area_is_valid
Incorrect device area lengths are being passed to device_area_is_valid().

The regression appeared in 2.6.31-rc1 through commit
754c5fc7eb.

With the dm-stripe target, the size of the target (ti->len) was used
instead of the stripe_width (ti->len/#stripes).  An example of a
consequent incorrect error message is:

  device-mapper: table: 254:0: sdb too small for target

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-07-23 20:30:42 +01:00
Mike Snitzer
a732c207d1 dm: remove queue next_ordered workaround for barriers
This patch removes DM's bio-based vs request-based conditional setting
of next_ordered.  For bio-based DM the next_ordered check is no longer a
concern (as that check is now in the __make_request path).  For
request-based DM the default of QUEUE_ORDERED_NONE is now appropriate.

bio-based DM was changed to work-around the previously misplaced
next_ordered check with this commit:
99360b4c18

request-based DM does not yet support barriers but reacted to the above
bio-based DM change with this commit:
5d67aa2366

The above changes are no longer needed given Neil Brown's recent fix to
put the next_ordered check in the __make_request path:
db64f680ba

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: NeilBrown <neilb@suse.de>
Acked-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-07-23 20:30:40 +01:00
Mikulas Patocka
69885683d2 dm raid1: wake kmirrord when requeueing delayed bios after remote recovery
The recent commit 7513c2a761 (dm raid1:
add is_remote_recovering hook for clusters) changed do_writes() to
update the ms->writes list but forgot to wake up kmirrord to process it.

The rule is that when anything is being added on ms->reads, ms->writes
or ms->failures and the list was empty before we must call
wakeup_mirrord (for immediate processing) or delayed_wake (for delayed
processing).  Otherwise the bios could sit on the list indefinitely.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
CC: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-07-23 20:30:37 +01:00
Dan Williams
a11034b428 md/raid6: release spare page at ->stop()
Add missing call to safe_put_page from stop() by unifying open coded
raid5_conf_t de-allocation under free_conf().

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-07-14 11:48:16 -07:00
Jens Axboe
8aa7e847d8 Fix congestion_wait() sync/async vs read/write confusion
Commit 1faa16d228 accidentally broke
the bdi congestion wait queue logic, causing us to wait on congestion
for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-07-10 20:31:53 +02:00
Joe Perches
ad361c9884 Remove multiple KERN_ prefixes from printk formats
Commit 5fd29d6ccb ("printk: clean up
handling of log-levels and newlines") changed printk semantics.  printk
lines with multiple KERN_<level> prefixes are no longer emitted as
before the patch.

<level> is now included in the output on each additional use.

Remove all uses of multiple KERN_<level>s in formats.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-08 10:30:03 -07:00
Linus Torvalds
2027bd9f92 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cfq-iosched: remove redundant check for NULL cfqq in cfq_set_request()
  blocK: Restore barrier support for md and probably other virtual devices.
  block: get rid of queue-private command filter
  block: Create bip slabs with embedded integrity vectors
  cfq-iosched: get rid of the need for __GFP_NOFAIL in cfq_find_alloc_queue()
  cfq-iosched: move cfqq initialization out of cfq_find_alloc_queue()
  Trivial typo fixes in Documentation/block/data-integrity.txt.
2009-07-01 10:41:09 -07:00
Linus Torvalds
544ae5f96e Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  md: use interruptible wait when duration is controlled by userspace.
  md/raid5: suspend shouldn't affect read requests.
  md: tidy up error paths in md_alloc
  md: fix error path when duplicate name is found on md device creation.
  md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes.
  md: Use new topology calls to indicate alignment and I/O sizes
2009-07-01 10:31:26 -07:00
Martin K. Petersen
7878cba9f0 block: Create bip slabs with embedded integrity vectors
This patch restores stacking ability to the block layer integrity
infrastructure by creating a set of dedicated bip slabs.  Each bip slab
has an embedded bio_vec array at the end.  This cuts down on memory
allocations and also simplifies the code compared to the original bvec
version.  Only the largest bip slab is backed by a mempool.  The pool is
contained in the bio_set so stacking drivers can ensure forward
progress.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.(none)>
2009-07-01 10:56:25 +02:00
NeilBrown
e62e58a5ff md: use interruptible wait when duration is controlled by userspace.
User space can set various limits on an md array so that resync waits
when it gets to a certain point, or so that I/O is blocked for a short
while.
When md is waiting against one of these limit, it should use an
interruptible wait so as not to add to the load average, and so are
not to trigger a warning if the wait goes on for too long.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 13:15:35 +10:00
NeilBrown
a5c308d4d1 md/raid5: suspend shouldn't affect read requests.
md allows write to regions on an array to be suspended temporarily.
This allows user-space to participate is aspects of reshape.
In particular, data can be copied with not risk of a race.
We should not be blocking read requests though, so don't.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 13:15:35 +10:00
NeilBrown
0909dc448c md: tidy up error paths in md_alloc
As the recent bug in md_alloc showed, having a single exit path for
unlocking and putting is a good idea.  So restructure md_alloc to have
a single mutex_unlock and mddev_put, and use gotos where necessary.

Found-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 12:27:21 +10:00
NeilBrown
1ec22eb2b4 md: fix error path when duplicate name is found on md device creation.
When an md device is created by name (rather than number) we need to
check that the name is not already in use.  If this check finds a
duplicate, we return an error without dropping the lock or freeing
the newly create mddev.
This patch fixes that.

Cc: stable@kernel.org
Found-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 12:27:21 +10:00
NeilBrown
b8d966efd9 md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes.
If we try to modify one of the md/ sysfs files
  suspend_lo or suspend_hi
when the array is not active, we dereference a NULL.
Protect against that.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 11:14:04 +10:00
Martin K. Petersen
8f6c2e4b32 md: Use new topology calls to indicate alignment and I/O sizes
Switch MD over to the new disk_stack_limits() function which checks for
aligment and adjusts preferred I/O sizes when stacking.

Also indicate preferred I/O sizes where applicable.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01 11:13:45 +10:00
Mike Snitzer
ea9df47cc9 dm table: fix blk_stack_limits arg to use bytes not sectors
The offset passed to blk_stack_limits() must be in bytes not sectors.
Fixes false warnings like the following:
device-mapper: table: 254:1: target device sda6 is misaligned

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reported-by: Frans Pop <elendil@planet.nl>
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-30 15:18:17 +01:00
Milan Broz
874d2f61d3 dm exception store: really fix type lookup
Fix exception store name handling.

We need to reference exception store by zero terminated string.

Fixes regression introduced in commit f6bd4eb73c

Cc: Yi Yang <yi.y.yang@intel.com>
Cc: Jonathan Brassow <jbrassow@redhat.com>
Cc: stable@kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-30 15:18:14 +01:00
Kiyoshi Ueda
f40c67f0f7 dm mpath: change to be request based
This patch converts dm-multipath target to request-based from bio-based.

Basically, the patch just converts the I/O unit from struct bio
to struct request.
In the course of the conversion, it also changes the I/O queueing
mechanism.  The change in the I/O queueing is described in details
as follows.

I/O queueing mechanism change
-----------------------------
In I/O submission, map_io(), there is no mechanism change from
bio-based, since the clone request is ready for retry as it is.
However, in I/O complition, do_end_io(), there is a mechanism change
from bio-based, since the clone request is not ready for retry.

In do_end_io() of bio-based, the clone bio has all needed memory
for resubmission.  So the target driver can queue it and resubmit
it later without memory allocations.
The mechanism has almost no overhead.

On the other hand, in do_end_io() of request-based, the clone request
doesn't have clone bios, so the target driver can't resubmit it
as it is.  To resubmit the clone request, memory allocation for
clone bios is needed, and it takes some overheads.
To avoid the overheads just for queueing, the target driver doesn't
queue the clone request inside itself.
Instead, the target driver asks dm core for queueing and remapping
the original request of the clone request, since the overhead for
queueing is just a freeing memory for the clone request.

As a result, the target driver doesn't need to record/restore
the information of the original request for resubmitting
the clone request.  So dm_bio_details in dm_mpath_io is removed.

multipath_busy()
---------------------
The target driver returns "busy", only when the following case:
  o The target driver will map I/Os, if map() function is called
  and
  o The mapped I/Os will wait on underlying device's queue due to
    their congestions, if map() function is called now.

In other cases, the target driver doesn't return "busy".
Otherwise, dm core will keep the I/Os and the target driver can't
do what it wants.
(e.g. the target driver can't map I/Os now, so wants to kill I/Os.)

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:37 +01:00
Kiyoshi Ueda
523d9297d4 dm: disable interrupt when taking map_lock
This patch disables interrupt when taking map_lock to avoid
lockdep warnings in request-based dm.

request-based dm takes map_lock after taking queue_lock with
disabling interrupt:
  spin_lock_irqsave(queue_lock)
  q->request_fn() == dm_request_fn()
    => dm_get_table()
         => read_lock(map_lock)
while queue_lock could be (but isn't) taken in interrupt context.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:37 +01:00
Kiyoshi Ueda
5d67aa2366 dm: do not set QUEUE_ORDERED_DRAIN if request based
Request-based dm doesn't have barrier support yet.
So we need to set QUEUE_ORDERED_DRAIN only for bio-based dm.
Since the device type is decided at the first table loading time,
the flag set is deferred until then.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:36 +01:00
Kiyoshi Ueda
e6ee8c0b76 dm: enable request based option
This patch enables request-based dm.

o Request-based dm and bio-based dm coexist, since there are
  some target drivers which are more fitting to bio-based dm.
  Also, there are other bio-based devices in the kernel
  (e.g. md, loop).
  Since bio-based device can't receive struct request,
  there are some limitations on device stacking between
  bio-based and request-based.

                     type of underlying device
                   bio-based      request-based
   ----------------------------------------------
    bio-based         OK                OK
    request-based     --                OK

  The device type is recognized by the queue flag in the kernel,
  so dm follows that.

o The type of a dm device is decided at the first table binding time.
  Once the type of a dm device is decided, the type can't be changed.

o Mempool allocations are deferred to at the table loading time, since
  mempools for request-based dm are different from those for bio-based
  dm and needed mempool type is fixed by the type of table.

o Currently, request-based dm supports only tables that have a single
  target.  To support multiple targets, we need to support request
  splitting or prevent bio/request from spanning multiple targets.
  The former needs lots of changes in the block layer, and the latter
  needs that all target drivers support merge() function.
  Both will take a time.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:36 +01:00
Kiyoshi Ueda
cec47e3d4a dm: prepare for request based option
This patch adds core functions for request-based dm.

When struct mapped device (md) is initialized, md->queue has
an I/O scheduler and the following functions are used for
request-based dm as the queue functions:
    make_request_fn: dm_make_request()
    pref_fn:         dm_prep_fn()
    request_fn:      dm_request_fn()
    softirq_done_fn: dm_softirq_done()
    lld_busy_fn:     dm_lld_busy()
Actual initializations are done in another patch (PATCH 2).

Below is a brief summary of how request-based dm behaves, including:
  - making request from bio
  - cloning, mapping and dispatching request
  - completing request and bio
  - suspending md
  - resuming md

  bio to request
  ==============
  md->queue->make_request_fn() (dm_make_request()) calls __make_request()
  for a bio submitted to the md.
  Then, the bio is kept in the queue as a new request or merged into
  another request in the queue if possible.

  Cloning and Mapping
  ===================
  Cloning and mapping are done in md->queue->request_fn() (dm_request_fn()),
  when requests are dispatched after they are sorted by the I/O scheduler.

  dm_request_fn() checks busy state of underlying devices using
  target's busy() function and stops dispatching requests to keep them
  on the dm device's queue if busy.
  It helps better I/O merging, since no merge is done for a request
  once it is dispatched to underlying devices.

  Actual cloning and mapping are done in dm_prep_fn() and map_request()
  called from dm_request_fn().
  dm_prep_fn() clones not only request but also bios of the request
  so that dm can hold bio completion in error cases and prevent
  the bio submitter from noticing the error.
  (See the "Completion" section below for details.)

  After the cloning, the clone is mapped by target's map_rq() function
    and inserted to underlying device's queue using
    blk_insert_cloned_request().

  Completion
  ==========
  Request completion can be hooked by rq->end_io(), but then, all bios
  in the request will have been completed even error cases, and the bio
  submitter will have noticed the error.
  To prevent the bio completion in error cases, request-based dm clones
  both bio and request and hooks both bio->bi_end_io() and rq->end_io():
      bio->bi_end_io(): end_clone_bio()
      rq->end_io():     end_clone_request()

  Summary of the request completion flow is below:
  blk_end_request() for a clone request
    => blk_update_request()
       => bio->bi_end_io() == end_clone_bio() for each clone bio
          => Free the clone bio
          => Success: Complete the original bio (blk_update_request())
             Error:   Don't complete the original bio
    => blk_finish_request()
       => rq->end_io() == end_clone_request()
          => blk_complete_request()
             => dm_softirq_done()
                => Free the clone request
                => Success: Complete the original request (blk_end_request())
                   Error:   Requeue the original request

  end_clone_bio() completes the original request on the size of
  the original bio in successful cases.
  Even if all bios in the original request are completed by that
  completion, the original request must not be completed yet to keep
  the ordering of request completion for the stacking.
  So end_clone_bio() uses blk_update_request() instead of
  blk_end_request().
  In error cases, end_clone_bio() doesn't complete the original bio.
  It just frees the cloned bio and gives over the error handling to
  end_clone_request().

  end_clone_request(), which is called with queue lock held, completes
  the clone request and the original request in a softirq context
  (dm_softirq_done()), which has no queue lock, to avoid a deadlock
  issue on submission of another request during the completion:
      - The submitted request may be mapped to the same device
      - Request submission requires queue lock, but the queue lock
        has been held by itself and it doesn't know that

  The clone request has no clone bio when dm_softirq_done() is called.
  So target drivers can't resubmit it again even error cases.
  Instead, they can ask dm core for requeueing and remapping
  the original request in that cases.

  suspend
  =======
  Request-based dm uses stopping md->queue as suspend of the md.
  For noflush suspend, just stops md->queue.

  For flush suspend, inserts a marker request to the tail of md->queue.
  And dispatches all requests in md->queue until the marker comes to
  the front of md->queue.  Then, stops dispatching request and waits
  for the all dispatched requests to complete.
  After that, completes the marker request, stops md->queue and
  wake up the waiter on the suspend queue, md->wait.

  resume
  ======
  Starts md->queue.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
Jonthan Brassow
f5db4af466 dm raid1: add userspace log
This patch contains a device-mapper mirror log module that forwards
requests to userspace for processing.

The structures used for communication between kernel and userspace are
located in include/linux/dm-log-userspace.h.  Due to the frequency,
diversity, and 2-way communication nature of the exchanges between
kernel and userspace, 'connector' was chosen as the interface for
communication.

The first log implementations written in userspace - "clustered-disk"
and "clustered-core" - support clustered shared storage.   A userspace
daemon (in the LVM2 source code repository) uses openAIS/corosync to
process requests in an ordered fashion with the rest of the nodes in the
cluster so as to prevent log state corruption.  Other implementations
with no association to LVM or openAIS/corosync, are certainly possible.

(Imagine if two machines are writing to the same region of a mirror.
They would both mark the region dirty, but you need a cluster-aware
entity that can handle properly marking the region clean when they are
done.  Otherwise, you might clear the region when the first machine is
done, not the second.)

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:35 +01:00
Mike Snitzer
754c5fc7eb dm: calculate queue limits during resume not load
Currently, device-mapper maintains a separate instance of 'struct
queue_limits' for each table of each device.  When the configuration of
a device is to be changed, first its table is loaded and this structure
is populated, then the device is 'resumed' and the calculated
queue_limits are applied.

This places restrictions on how userspace may process related devices,
where it is often advantageous to 'load' tables for several devices
at once before 'resuming' them together.  As the new queue_limits
only take effect after the 'resume', if they are changing and one
device uses another, the latter must be 'resumed' before the former
may be 'loaded'.

This patch moves the calculation of these queue_limits out of
the 'load' operation into 'resume'.  Since we are no longer
pre-calculating this struct, we no longer need to maintain copies
within our dm structs.

dm_set_device_limits() now passes the 'start' of the device's
data area (aka pe_start) as the 'offset' to blk_stack_limits().

init_valid_queue_limits() is replaced by blk_set_default_limits().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: martin.petersen@oracle.com
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:34 +01:00
Mike Snitzer
18d8594dd9 dm log: fix create_log_context to use logical_block_size of log device
create_log_context() must use the logical_block_size from the log disk,
where the I/O happens, not the target's logical_block_size.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:33 +01:00
Mike Snitzer
af4874e03e dm target:s introduce iterate devices fn
Add .iterate_devices to 'struct target_type' to allow a function to be
called for all devices in a DM target.  Implemented it for all targets
except those in dm-snap.c (origin and snapshot).

(The raid1 version number jumps to 1.12 because we originally reserved
1.1 to 1.11 for 'block_on_error' but ended up using 'handle_errors'
instead.)

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: martin.petersen@oracle.com
2009-06-22 10:12:33 +01:00
Mike Snitzer
1197764e40 dm table: establish queue limits by copying table limits
Copy the table's queue_limits to the DM device's request_queue.  This
properly initializes the queue's topology limits and also avoids having
to track the evolution of 'struct queue_limits' in
dm_table_set_restrictions()

Also fixes a bug that was introduced in dm_table_set_restrictions() via
commit ae03bf639a.  In addition to
establishing 'bounce_pfn' in the queue's limits blk_queue_bounce_limit()
also performs an allocation to setup the ISA DMA pool.  This allocation
resulted in "sleeping function called from invalid context" when called
from dm_table_set_restrictions().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:32 +01:00
Mike Snitzer
5ab97588fb dm table: replace struct io_restrictions with struct queue_limits
Use blk_stack_limits() to stack block limits (including topology) rather
than duplicate the equivalent within Device Mapper.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:32 +01:00
Mike Snitzer
be6d4305db dm table: validate device logical_block_size
Impose necessary and sufficient conditions on a devices's table such
that any incoming bio which respects its logical_block_size can be
processed successfully.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:31 +01:00
Mike Snitzer
02acc3a4fa dm table: ensure targets are aligned to logical_block_size
Ensure I/O is aligned to the logical block size of target devices.

Rename check_device_area() to device_area_is_valid() for clarity and
establish the device limits including the logical block size prior to
calling it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:30 +01:00
Milan Broz
60935eb21d dm ioctl: support cookies for udev
Add support for passing a 32 bit "cookie" into the kernel with the
DM_SUSPEND, DM_DEV_RENAME and DM_DEV_REMOVE ioctls.  The (unsigned)
value of this cookie is returned to userspace alongside the uevents
issued by these ioctls in the variable DM_COOKIE.

This means the userspace process issuing these ioctls can be notified
by udev after udev has completed any actions triggered.

To minimise the interface extension, we pass the cookie into the
kernel in the event_nr field which is otherwise unused when calling
these ioctls.  Incrementing the version number allows userspace to
determine in advance whether or not the kernel supports the cookie.
If the kernel does support this but userspace does not, there should
be no impact as the new variable will just get ignored.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:30 +01:00
Peter Rajnoha
486d220fe4 dm: sysfs add suspended attribute
Add a file named 'suspended' to each device-mapper device directory in
sysfs.  It holds the value 1 while the device is suspended.  Otherwise
it holds 0.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:29 +01:00
Jonthan Brassow
1b6da75459 dm table: improve warning message when devices not freed before destruction
Report any devices forgotten to be freed before a table is destroyed.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:29 +01:00
Kiyoshi Ueda
f392ba889b dm mpath: add service time load balancer
This patch adds a service time oriented dynamic load balancer,
dm-service-time, which selects the path with the shortest estimated
service time for the incoming I/O.
The service time is estimated by dividing the in-flight I/O size
by a performance value of each path.

The performance value can be given as a table argument at the table
loading time.  If no performance value is given, all paths are
considered equal.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:28 +01:00
Kiyoshi Ueda
fd5e033908 dm mpath: add queue length load balancer
This patch adds a dynamic load balancer, dm-queue-length, which
balances the number of in-flight I/Os across the paths.

The code is based on the patch posted by Stefan Bader:
https://www.redhat.com/archives/dm-devel/2005-October/msg00050.html

Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:27 +01:00
Kiyoshi Ueda
02ab823fd1 dm mpath: add start_io and nr_bytes to path selectors
This patch makes two additions to the dm path selector interface for
dynamic load balancers:
  o a new hook, start_io()
  o a new parameter 'nr_bytes' to select_path()/start_io()/end_io()
    to pass the size of the I/O

start_io() is called when a target driver actually submits I/O
to the selected path.
Path selectors can use it to start accounting of the I/O.
(e.g. counting the number of in-flight I/Os.)
The start_io hook is based on the patch posted by Stefan Bader:
https://www.redhat.com/archives/dm-devel/2005-October/msg00050.html

nr_bytes, the size of the I/O, is so path selectors can take the
size of the I/O into account when deciding which path to use.
dm-service-time uses it to estimate service time, for example.
(Added the nr_bytes member to dm_mpath_io instead of using existing
 details.bi_size, since request-based dm patch deletes it.)

Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:27 +01:00
Mikulas Patocka
2bd0234525 dm snapshot: use barrier when writing exception store
Send barrier requests when updating the exception area.

Exception area updates need to be ordered w.r.t. data writes, so that
the writes are not reordered in hardware disk cache.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:26 +01:00
Mikulas Patocka
51aa322849 dm io: retry after barrier error
If -EOPNOTSUPP was returned and the request was a barrier request, retry it
without barrier.

Retry all regions for now. Barriers are submitted only for one-region requests,
so it doesn't matter.  (In the future, retries can be limited to the actual
regions that failed.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:26 +01:00
Mikulas Patocka
5af443a7e1 dm io: record eopnotsupp
Add another field, eopnotsupp_bits. It is subset of error_bits, representing
regions that returned -EOPNOTSUPP.  (The bit is set in both error_bits and
eopnotsupp_bits).

This value will be used in further patches.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:25 +01:00
Mikulas Patocka
494b3ee7d4 dm snapshot: support barriers
Flush support for dm-snapshot target.

This patch just forwards the flush request to either the origin or the snapshot
device.  (It doesn't flush exception store metadata.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:25 +01:00
Mikulas Patocka
8627921fa2 dm mpath: support barriers
Flush support for dm-multipath target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:24 +01:00
Mikulas Patocka
c927259e34 dm delay: support barriers
Flush support for dm-delay target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:23 +01:00
Mikulas Patocka
647c7db14e dm crypt: support flush
Flush support for dm-crypt target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:23 +01:00
Mikulas Patocka
374bf7e7f6 dm: stripe support flush
Flush support for the stripe target.

This sets ti->num_flush_requests to the number of stripes and
remaps individual flush requests to the appropriate stripe devices.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:22 +01:00
Mikulas Patocka
433bcac564 dm: linear support flush
Flush support for the linear target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:22 +01:00
Mikulas Patocka
52b1fd5a27 dm: send empty barriers to targets in dm_flush
Pass empty barrier flushes to the targets in dm_flush().

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:21 +01:00
Alasdair G Kergon
9015df24a8 dm: initialise tio in alloc_tio
Move repeated dm_target_io initialisation inside alloc_tio().

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:21 +01:00
Mikulas Patocka
f9ab94cee3 dm: introduce num_flush_requests
Introduce num_flush_requests for a target to set to say how many flush
instructions (empty barriers) it wants to receive.  These are sent by
__clone_and_map_empty_barrier with map_info->flush_request going from 0
to (num_flush_requests - 1).

Old targets without flush support won't receive any flush requests.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:20 +01:00
Mikulas Patocka
27eaa14975 dm: remove check that prevents mapping empty bios
Remove the check that the size of the cloned bio is not zero because a
subsequent patch needs to send zero-sized barriers down this path.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:20 +01:00
Mikulas Patocka
fdb9572b73 dm: remove EOPNOTSUPP for barriers
If the underlying device doesn't support barriers and dm receives a
barrier, it waits until all requests on that device drain so it no
longer needs to report -EOPNOTSUPP to the caller.

This patch deals with the confusing situation when moving a volume from
one physical device to another triggers an EOPNOTSUPP on a volume that
didn't report it before.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:19 +01:00
Mikulas Patocka
5aa2781d96 dm: store only first barrier error
With the following patches, more than one error can occur during
processing.  Change md->barrier_error so that only the first one is
recorded and returned to the caller.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:18 +01:00
Mikulas Patocka
2761e95fe4 dm: process requeue in dm_wq_work
If barrier request was returned with DM_ENDIO_REQUEUE,
requeue it in dm_wq_work instead of dec_pending.

This allows us to correctly handle a situation when some targets
are asking for a requeue and other targets signal an error.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:18 +01:00
Mikulas Patocka
531fe96364 dm: make dm_flush return void
Make dm_flush return void.

The first error during flush is stored in md->barrier_error instead.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:17 +01:00
Mikulas Patocka
32a926da5a dm: always hold bdev reference
Fix a potential deadlock when creating multiple snapshots by holding a
reference to struct block_device for the whole lifecycle of every dm
device instead of obtaining it independently at each point it is needed.

bdget_disk() was called while the device was being suspended, in
dm_suspend().  However there could be other devices already suspended,
for example when creating additional snapshots of a device. bdget_disk()
can wait for IO and allocate memory resulting in waiting for the
already-suspended device - deadlock.

This patch changes the code so that it gets the reference to struct
block_device when struct mapped_device is allocated and initialized in
alloc_dev() where it is always OK to allocate memory or wait for I/O.
It drops the reference when it is destroyed in free_dev().  Thus there
is no call to bdget_disk() while any device is suspended.

Previously unlock_fs() was called only if bdev was held.  Now it is
called unconditionally, but the superfluous calls are harmless because
it returns immediately if the filesystem was not previously frozen.

This patch also now allows the device size to be changed in a
noflush suspend because the bdev is held.  This has no adverse effect.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:17 +01:00
Mikulas Patocka
db8fef4fab dm: rename suspended_bdev to bdev
Rename suspended_bdev to bdev.

This patch doesn't change any functionality, just renames the variable.
In the next patch, the variable will be used even for non-suspended device.

(Pre-requisite for the per-target barrier support patches.)

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:15 +01:00
Jonathan Brassow
f6bd4eb73c dm exception store: fix exstore lookup to be case insensitive
When snapshots are created using 'p' instead of 'P' as the
exception store type, the device-mapper table loading fails.

This patch makes the code case insensitive as intended and fixes some
regressions reported with device-mapper snapshots.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:15 +01:00
Mikulas Patocka
5657e8fa45 dm: use i_size_read
Use i_size_read() instead of reading i_size.

If someone changes the size of the device simultaneously, i_size_read
is guaranteed to return a valid value (either the old one or the new one).

i_size can return some intermediate invalid value (on 32-bit computers
with 64-bit i_size, the reads to both halves of i_size can be interleaved
with updates to i_size, resulting in garbage being returned).

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:14 +01:00
Mikulas Patocka
8cbeb67ad5 dm: avoid unsupported spanning of md stripe boundaries
A bio that has two or more vector entries, size less than or equal to
page size, that crosses a stripe boundary of an underlying md device is
accepted by device mapper (it conforms to all its limits) but not by the
underlying device.

The fix is: If device mapper selects the one-page maximum request size,
it also needs to set its own q->merge_bvec_fn to reject any bios with
multiple vector entries that span more pages.

The problem was discovered in the following scenario:
  * MD - RAID-0
  * LV on the top of it (raid1, snapshot or striped with chunk
size/stripe larger than RAID-0 stripe)
  * one of the logical volumes is exported to xen domU
  * inside xen domU it is partitioned, the key point is that the partition
must be unaligned on page boundary (fdisk normally aligns the partition to
63 sectors which will trigger it)
  * install the system on the partitioned disk in domU
This causes I/O failures in dom0.
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=223947

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:14 +01:00
Mikulas Patocka
53b351f972 dm mpath: flush keventd queue in destructor
The commit fe9cf30eb8 moves dm table event
submission from kmultipath queue to kernel kevent queue to avoid a
deadlock.

There is a possibility of race condition because kevent queue is not flushed
in the multipath destructor. The scenario is:
- some event happens and is queued to keventd
- keventd thread is delayed due to scheuling latency or some other work
- multipath device is destroyed
- keventd now attempts to process work_struct that is residing in already
  released memory.

The patch flushes the keventd queue in multipath constructor.
I've already fixed similar bug in dm-raid1.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
2009-06-22 10:12:13 +01:00
Mikulas Patocka
a72986c562 dm raid1: keep retrying alloc if mempool_alloc failed
If the code can't handle allocation failures, use __GFP_NOFAIL so that
in case of memory pressure the allocator will retry indefinitely and
won't return NULL which would cause a crash in the function.

This is still not a correct fix, it may cause a classic deadlock when
memory manager waits for I/O being done and I/O waits for some free memory.
I/O code shouldn't allocate any memory. But in this case it probably
doesn't matter much in practice, people usually do not swap on RAID.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:13 +01:00
Chandra Seetharaman
e54f77ddda dm mpath: call activate fn for each path in pg_init
Fixed a problem affecting reinstatement of passive paths.

Before we moved the hardware handler from dm to SCSI, it performed a pg_init
for a path group and didn't maintain any state about each path in hardware
handler code.

But in SCSI dh, such state is now maintained, as we want to fail I/O early on a
path if it is not the active path.

All the hardware handlers have a state now and set to active or some form of
inactive.  They have prep_fn() which uses this state to fail the I/O without
it ever being sent to the device.

So in effect when dm-multipath calls scsi_dh_activate(), activate is
sent to only one path and the "state" of that path is changed appropriately
to "active" while other paths in the same path group are never changed
as they never got an "activate".

In order make sure all the paths in a path group gets their state set
properly when a pg_init happens, we need to call scsi_dh_activate() on
all paths in a path group.

Doing this at the hardware handler layer is not a good option as we
want the multipath layer to define the relationship between path and path
groups and not the hardware handler.

Attached patch sends an "activate" on each path in a path group when a
path group is switched. It also sends an activate when a path is reinstated.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:12 +01:00
Hannes Reinecke
a0cf7ea954 dm mpath: change attached scsi_dh
When specifying a different hardware handler via multipath
features we should be able to override the built-in defaults.

The problem here is the hardware table from scsi_dh is compiled
in and cannot be changed from userland. The multipath.conf OTOH
is purely user-defined and, what's more, the user might have a valid
reason for modifying it.
(EG EMC Clariion can well be run in PNR mode even though ALUA is
active, or the user might want to try ALUA on any as-of-yet unknown
devices)

So _not_ allowing multipath to override the device handler setting
will just add to the confusion and makes error tracking even more
difficult.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:11 +01:00
Milan Broz
4d89b7b4e4 dm: sysfs skip output when device is being destroyed
Do not process sysfs attributes when device is being destroyed.

Otherwise code can cause
  BUG_ON(test_bit(DMF_FREEING, &md->flags));
in dm_put() call.

Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:11 +01:00
Mikulas Patocka
e094f4f15f dm mpath: validate hw_handler argument count
Fix arg count parsing error in hw handlers.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:12:10 +01:00
Mikulas Patocka
0e0497c0c0 dm mpath: validate table argument count
The parser reads the argument count as a number but doesn't check that
sufficient arguments are supplied. This command triggers the bug:

dmsetup create mpath --table "0 `blockdev --getsize /dev/mapper/cr0`
    multipath 0 0 2 1 round-robin 1000 0 1 1 /dev/mapper/cr0
    round-robin 0 1 1 /dev/mapper/cr1 1000"
kernel BUG at drivers/md/dm-mpath.c:530!

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 10:08:02 +01:00
Linus Torvalds
31583d6acf Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  Fix kernel-doc parameter name typo in blk-settings.c:
  block: rename CONFIG_LBD to CONFIG_LBDAF
  block: Fix bounce_pfn setting
  hd: stop defining MAJOR_NR
2009-06-19 17:43:04 -07:00
Bartlomiej Zolnierkiewicz
90c699a9ee block: rename CONFIG_LBD to CONFIG_LBDAF
Follow-up to "block: enable by default support for large devices
and files on 32-bit archs".

Rename CONFIG_LBD to CONFIG_LBDAF to:
- allow update of existing [def]configs for "default y" change
- reflect that it is used also for large files support nowadays

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-06-19 08:08:50 +02:00
Linus Torvalds
9729a6eb58 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (39 commits)
  md/raid5: correctly update sync_completed when we reach max_resync
  md/raid5: add missing call to schedule() after prepare_to_wait()
  md/linear: use call_rcu to free obsolete 'conf' structures.
  md linear: Protecting mddev with rcu locks to avoid races
  md: Move check for bitmap presence to personality code.
  md: remove chunksize rounding from common code.
  md: raid0/linear: ensure device sizes are rounded to chunk size.
  md: move assignment of ->utime so that it never gets skipped.
  md: Push down reconstruction log message to personality code.
  md: merge reconfig and check_reshape methods.
  md: remove unnecessary arguments from ->reconfig method.
  md: raid5: check stripe cache is large enough in start_reshape
  md: raid0: chunk_sectors cleanups.
  md: fix some comments.
  md/raid5: Use is_power_of_2() in raid5_reconfig()/raid6_reconfig().
  md: convert conf->chunk_size and conf->prev_chunk to sectors.
  md: Convert mddev->new_chunk to sectors.
  md: Make mddev->chunk_size sector-based.
  md: raid0 :Enables chunk size other than powers of 2.
  md: prepare for non-power-of-two chunk sizes
  ...
2009-06-18 13:11:50 -07:00
NeilBrown
48606a9f2f md/raid5: correctly update sync_completed when we reach max_resync
At the end of reshape_request we update cyrr_resync_completed
if we are about to pause due to reaching resync_max.
However we update it to the wrong value.  We need to add the
"reshape_sectors" that have just been reshaped.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 09:14:12 +10:00
Dan Williams
7a3ab90894 md/raid5: add missing call to schedule() after prepare_to_wait()
In the unlikely event that reshape progresses past the current request
while it is waiting for a stripe we need to schedule() before retrying
for 2 reasons:
1/ Prevent list corruption from duplicated list_add() calls without
   intervening list_del().
2/ Give the reshape code a chance to make some progress to resolve the
   conflict.

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:50:18 +10:00
NeilBrown
495d357301 md/linear: use call_rcu to free obsolete 'conf' structures.
Current, when we update the 'conf' structure, when adding a
drive to a linear array, we keep the old version around until
the array is finally stopped, as it is not safe to free it
immediately.

Now that we have rcu protection on all accesses to 'conf',
we can use call_rcu to free it more promptly.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:49:42 +10:00
SandeepKsinha
af11c397fd md linear: Protecting mddev with rcu locks to avoid races
Due to the lack of memory ordering guarantees, we may have races around
mddev->conf.

In particular, the correct contents of the structure we get from
dereferencing ->private might not be visible to this CPU yet, and
they might not be correct w.r.t mddev->raid_disks.

This patch addresses the problem using rcu protection to avoid
such race conditions.

Signed-off-by: SandeepKsinha <sandeepksinha@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:49:35 +10:00
Andre Noll
0894cc3066 md: Move check for bitmap presence to personality code.
If the superblock of a component device indicates the presence of a
bitmap but the corresponding raid personality does not support bitmaps
(raid0, linear, multipath, faulty), then something is seriously wrong
and we'd better refuse to run such an array.

Currently, this check is performed while the superblocks are examined,
i.e. before entering personality code. Therefore the generic md layer
must know which raid levels support bitmaps and which do not.

This patch avoids this layer violation without adding identical code
to various personalities. This is accomplished by introducing a new
public function to md.c, md_check_no_bitmap(), which replaces the
hard-coded checks in the superblock loading functions.

A call to md_check_no_bitmap() is added to the ->run method of each
personality which does not support bitmaps and assembly is aborted
if at least one component device contains a bitmap.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:49:23 +10:00
NeilBrown
8190e754e0 md: remove chunksize rounding from common code.
It is easiest to round sizes to multiples of chunk size in
the personality code for those personalities which care.
Those personalities now do the rounding, so we can
remove that function from common code.

Also remove the upper bound on the size of a chunk, and the lower
bound on the size of a device (1 chunk), neither of which really buy
us anything.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:48:58 +10:00
NeilBrown
13f2682b72 md: raid0/linear: ensure device sizes are rounded to chunk size.
This is currently ensured by common code, but it is more reliable to
ensure it where it is needed in personality code.
All the other personalities that care already round the size to
the chunk_size.  raid0 and linear are the only hold-outs.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:48:55 +10:00
NeilBrown
1b57f13223 md: move assignment of ->utime so that it never gets skipped.
Currently the assignment to utime gets skipped for 'external'
metadata.  So move it to the top of the function so that it
always gets effected.
This is of largely cosmetic interest.  Nothing actually depends
on ->utime being right for external arrays.
"mdadm --monitor" does use it for 0.90 and 1.x arrays, but with
mdadm-3.0, this is not important for external metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:48:19 +10:00
Andre Noll
8c6ac868b1 md: Push down reconstruction log message to personality code.
Currently, the md layer checks in analyze_sbs() if the raid level
supports reconstruction (mddev->level >= 1) and if reconstruction is
in progress (mddev->recovery_cp != MaxSector).

Move that printk into the personality code of those raid levels that
care (levels 1, 4, 5, 6, 10).

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:48:06 +10:00
NeilBrown
50ac168a6e md: merge reconfig and check_reshape methods.
The difference between these two methods is artificial.
Both check that a pending reshape is valid, and perform any
aspect of it that can be done immediately.
'reconfig' handles chunk size and layout.
'check_reshape' handles raid_disks.

So make them just one method.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:47:55 +10:00
NeilBrown
597a711b69 md: remove unnecessary arguments from ->reconfig method.
Passing the new layout and chunksize as args is not necessary as
the mddev has fields for new_check and new_layout.

This is preparation for combining the check_reshape and reconfig
methods

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:47:42 +10:00
NeilBrown
01ee22b496 md: raid5: check stripe cache is large enough in start_reshape
In reshape cases that do not change the number of devices,
start_reshape is called without first calling check_reshape.

Currently, the check that the stripe_cache is large enough is
only done in check_reshape.  It should be in start_reshape too.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:47:20 +10:00
NeilBrown
d6e412eaa5 md: raid0: chunk_sectors cleanups.
following the conversion to chunk_sectors, there is room
for cleaning up a little.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:47:00 +10:00
Andre Noll
cdc2ae6d6a md: fix some comments.
1/ Raid5 has learned to take over also raid4 and raid6 arrays.
2/ new_chunk in mdp_superblock_1 is in sectors, not bytes.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:46:47 +10:00
Andre Noll
0ba459d262 md/raid5: Use is_power_of_2() in raid5_reconfig()/raid6_reconfig().
Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:46:10 +10:00
Andre Noll
09c9e5fa1b md: convert conf->chunk_size and conf->prev_chunk to sectors.
This kills some more shifts.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:45:55 +10:00
Andre Noll
664e7c413f md: Convert mddev->new_chunk to sectors.
A straight-forward conversion which gets rid of some
multiplications/divisions/shifts. The patch also introduces a couple
of new ones, most of which are due to conf->chunk_size still being
represented in bytes. This will be cleaned up in subsequent patches.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:45:27 +10:00
Andre Noll
9d8f036362 md: Make mddev->chunk_size sector-based.
This patch renames the chunk_size field to chunk_sectors with the
implied change of semantics.  Since

	is_power_of_2(chunk_size) = is_power_of_2(chunk_sectors << 9)
				  = is_power_of_2(chunk_sectors)

these bits don't need an adjustment for the shift.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18 08:45:01 +10:00
Linus Torvalds
6fd03301d7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (64 commits)
  debugfs: use specified mode to possibly mark files read/write only
  debugfs: Fix terminology inconsistency of dir name to mount debugfs filesystem.
  xen: remove driver_data direct access of struct device from more drivers
  usb: gadget: at91_udc: remove driver_data direct access of struct device
  uml: remove driver_data direct access of struct device
  block/ps3: remove driver_data direct access of struct device
  s390: remove driver_data direct access of struct device
  parport: remove driver_data direct access of struct device
  parisc: remove driver_data direct access of struct device
  of_serial: remove driver_data direct access of struct device
  mips: remove driver_data direct access of struct device
  ipmi: remove driver_data direct access of struct device
  infiniband: ehca: remove driver_data direct access of struct device
  ibmvscsi: gadget: at91_udc: remove driver_data direct access of struct device
  hvcs: remove driver_data direct access of struct device
  xen block: remove driver_data direct access of struct device
  thermal: remove driver_data direct access of struct device
  scsi: remove driver_data direct access of struct device
  pcmcia: remove driver_data direct access of struct device
  PCIE: remove driver_data direct access of struct device
  ...

Manually fix up trivial conflicts due to different direct driver_data
direct access fixups in drivers/block/{ps3disk.c,ps3vram.c}
2009-06-16 12:57:37 -07:00
Li Zefan
e212d6f250 block: remove some includings of blktrace_api.h
When porting blktrace to tracepoints, we changed to trace/block.h
for trace prober declarations.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-06-16 11:19:36 +02:00
raz ben yehuda
fbb704efb7 md: raid0 :Enables chunk size other than powers of 2.
Maintain two flows, one for pow2 chunk sizes (which uses masks and
shift), and a flow for the general case (which uses sector_div).
This is for the sake of performance.

 - introduce map_sector and is_io_in_chunk_boundary to encapsulate
   those two flows better for raid0_make_request
 - fix blk_mergeable to support the two flows.

Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 17:02:05 +10:00
raz ben yehuda
2ac06c3332 md: prepare for non-power-of-two chunk sizes
Remove chunk size check from md as this is now performed in the run
function in each personality.

Replace chunk size power 2 code calculations by a regular division.

Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 17:01:42 +10:00
raz ben yehuda
740da44918 md: raid5: chunk size check in setup_conf
have raid5 check chunk size in run/reshape method instead of in md

Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 17:01:36 +10:00
raz ben yehuda
964e7913b0 md: raid10: chunk size check in run
have raid10 check chunk size in run method instead of in md

Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 17:01:22 +10:00
raz ben yehuda
92e59b6ba2 md: raid0: chunk size check in raid0_run
have raid0 check chunk size in run method instead of in md.
This is part of a series moving the checks from common code to
the personalities where they belong.

hardsect is short and chunksize is an int, so it is safe to use %.

Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 17:00:57 +10:00
raz ben yehuda
46994191ae md: have raid0 report its formation
Report to the user what are the raid zones

Signed-off-by: raziebe@gmail.com
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 17:00:54 +10:00
raz ben yehuda
1b9614291e md: have raid0 compile with MD_DEBUG on
Because of the removal of the device list from
the strips raid0 did not compile with MD_DEBUG flag on

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:57:40 +10:00
Sandeep K Sinha
aece3d1f40 md: Binary search in linear raid
Replace the linear search with binary search in which_dev.

Signed-off-by: Sandeep K Sinha <sandeepksinha@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:57:08 +10:00
Sandeep K Sinha
4db7cdc859 md: Removing num_sector and replacing start_sector with end_sector
Remove num_sectors from dev_info and replace start_sector with
end_sector.  This makes a lot of comparisons much simpler.

Signed-off-by: Sandeep K Sinha <sandeepksinha@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:56:13 +10:00
Sandeep K Sinha
45d4582f21 md: Removal of hash table in linear raid
Get rid of sector_div and hash table for linear raid and replace
with a linear search in which_dev.
The hash table adds a lot of complexity for little if any gain.
Ultimately a binary search will be used which will have smaller
cache foot print, a similar number of memory access, and no
divisions.

Signed-off-by: Sandeep K Sinha <sandeepksinha@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:55:26 +10:00
NeilBrown
070ec55d07 md: remove mddev_to_conf "helper" macro
Having a macro just to cast a void* isn't really helpful.
I would must rather see that we are simply de-referencing ->private,
than have to know what the macro does.

So open code the macro everywhere and remove the pointless cast.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:54:21 +10:00
NeilBrown
a6b3deafe0 md: raid0: remove setting of segment boundary.
This setting doesn't seem to make sense (half the chunk size??) and
shouldn't be needed.
The segment boundary exported by raid0 should simply be the minimum
of the segment boundary of all component devices.  And we already
get that right.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:54:07 +10:00
NeilBrown
b414579f45 md: raid0: remove ->dev pointer from strip_zone structure
If we treat conf->devlist more like a 2 dimensional array,
we can get the devlist for a particular zone simply by indexing
that array, so we don't need to store the pointers to subarrays
in strip_zone.  This makes strip_zone smaller and so (hopefully)
searches faster.

Signed-of-by: NeilBrown <neilb@suse.de>
2009-06-16 16:50:52 +10:00
NeilBrown
49f357a22b md: raid0: remove ->sectors from the strip_zone structure.
storing ->sectors is redundant as is can be computed from the
difference  z->zone_end - (z-1)->zone_end

The one place where it is used, it is just as efficient to use
a zone_end value instead.

And removing it makes strip_zone smaller, so they array of these that
is searched on every request has a better chance to say in cache.

So discard the field and get the value from elsewhere.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:50:35 +10:00
Andre Noll
fb5ab4b5d6 md: raid0: Fix a memory leak when stopping a raid0 array.
raid0_stop() removes all references to the raid0 configuration but
misses to free the ->devlist buffer.

This patch closes this leak, removes a pointless initialization and
fixes a coding style issue in raid0_stop().

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:48:19 +10:00
Andre Noll
ed7b00380d md: raid0: Allocate all buffers for the raid0 configuration in one function.
Currently the raid0 configuration is allocated in raid0_run() while
the buffers for the strip_zone and the dev_list arrays are allocated
in create_strip_zones(). On errors, all three buffers are freed
in raid0_run().

It's easier and more readable to do the allocation and cleanup within
a single function. So move that code into create_strip_zones().

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:47:36 +10:00
Andre Noll
5568a6035d md: raid0: Make raid0_run() return a proper error code.
Currently raid0_run() always returns -ENOMEM on errors. This is
incorrect as running the array might fail for other reasons, for
example because not all component devices were available.

This patch changes create_strip_zones() so that it returns a proper
error code (either -ENOMEM or -EINVAL) rather than 1 on errors and
makes raid0_run(), its single caller, return that value instead
of -ENOMEM.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:47:21 +10:00
Andre Noll
8f79cfcdb6 md: raid0: Remove hash spacing and sector shift.
The "sector_shift" and "spacing" fields of struct raid0_private_data
were only used for the hash table lookups. So the removal of the
hash table allows get rid of these fields as well which simplifies
create_strip_zones() and raid0_run() quite a bit.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:47:10 +10:00
Andre Noll
09770e0b6e md: raid0: Remove hash table.
The raid0 hash table has become unused due to the changes in the
previous patch. This patch removes the hash table allocation and
setup code and kills the hash_table field of struct raid0_private_data.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:46:48 +10:00
NeilBrown
d27a43abd7 md/raid0: two cleanups in create_stripe_zones.
1/ remove current_start.  The same value is available in
     zone->dev_start and storing it separately doesn't gain anything.
2/ rename curr_zone_start to curr_zone_end as we are now more
     focused on the 'end' of each zone.  We end up storing the
     same number though - the old name was a little confusing
     (and what does 'current' mean in this context anyway).

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:46:46 +10:00
Andre Noll
dc58266385 md: raid0: Replace hash table lookup by looping over all strip_zones.
The number of strip_zones of a raid0 array is bounded by the number of
drives in the array and is in fact much smaller for typical setups. For
example, any raid0 array containing identical disks will have only
a single strip_zone.

Therefore, the hash tables which are used for quickly finding the
strip_zone that holds a particular sector are of questionable value
and add quite a bit of unnecessary complexity.

This patch replaces the hash table lookup by equivalent code which
simply loops over all strip zones to find the zone that holds the
given sector.

In order to make this loop as fast as possible, the zone->start field
of struct strip_zone has been renamed to zone_end, and it now stores
the beginning of the next zone in sectors. This allows to save one
addition in the loop.

Subsequent cleanup patches will remove the hash table structure.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16 16:18:43 +10:00
Kay Sievers
d405640539 Driver Core: misc: add nodename support for misc devices.
This adds support for misc devices to report their requested nodename to
userspace.  It also updates a number of misc drivers to provide the
needed subdirectory and device name to be used for them.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15 21:30:25 -07:00
Linus Torvalds
c9059598ea Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block: (153 commits)
  block: add request clone interface (v2)
  floppy: fix hibernation
  ramdisk: remove long-deprecated "ramdisk=" boot-time parameter
  fs/bio.c: add missing __user annotation
  block: prevent possible io_context->refcount overflow
  Add serial number support for virtio_blk, V4a
  block: Add missing bounce_pfn stacking and fix comments
  Revert "block: Fix bounce limit setting in DM"
  cciss: decode unit attention in SCSI error handling code
  cciss: Remove no longer needed sendcmd reject processing code
  cciss: change SCSI error handling routines to work with interrupts enabled.
  cciss: separate error processing and command retrying code in sendcmd_withirq_core()
  cciss: factor out fix target status processing code from sendcmd functions
  cciss: simplify interface of sendcmd() and sendcmd_withirq()
  cciss: factor out core of sendcmd_withirq() for use by SCSI error handling code
  cciss: Use schedule_timeout_uninterruptible in SCSI error handling code
  block: needs to set the residual length of a bidi request
  Revert "block: implement blkdev_readpages"
  block: Fix bounce limit setting in DM
  Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txt
  ...

Manually fix conflicts with tracing updates in:
	block/blk-sysfs.c
	drivers/ide/ide-atapi.c
	drivers/ide/ide-cd.c
	drivers/ide/ide-floppy.c
	drivers/ide/ide-tape.c
	include/trace/events/block.h
	kernel/trace/blktrace.c
2009-06-11 11:10:35 -07:00
Linus Torvalds
8623661180 Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits)
  Revert "x86, bts: reenable ptrace branch trace support"
  tracing: do not translate event helper macros in print format
  ftrace/documentation: fix typo in function grapher name
  tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK
  tracing: add protection around module events unload
  tracing: add trace_seq_vprint interface
  tracing: fix the block trace points print size
  tracing/events: convert block trace points to TRACE_EVENT()
  ring-buffer: fix ret in rb_add_time_stamp
  ring-buffer: pass in lockdep class key for reader_lock
  tracing: add annotation to what type of stack trace is recorded
  tracing: fix multiple use of __print_flags and __print_symbolic
  tracing/events: fix output format of user stack
  tracing/events: fix output format of kernel stack
  tracing/trace_stack: fix the number of entries in the header
  ring-buffer: discard timestamps that are at the start of the buffer
  ring-buffer: try to discard unneeded timestamps
  ring-buffer: fix bug in ring_buffer_discard_commit
  ftrace: do not profile functions when disabled
  tracing: make trace pipe recognize latency format flag
  ...
2009-06-10 19:53:40 -07:00
Li Zefan
55782138e4 tracing/events: convert block trace points to TRACE_EVENT()
TRACE_EVENT is a more generic way to define tracepoints. Doing so adds
these new capabilities to this tracepoint:

  - zero-copy and per-cpu splice() tracing
  - binary tracing without printf overhead
  - structured logging records exposed under /debug/tracing/events
  - trace events embedded in function tracer output and other plugins
  - user-defined, per tracepoint filter expressions
  ...

Cons:

  - no dev_t info for the output of plug, unplug_timer and unplug_io events.
    no dev_t info for getrq and sleeprq events if bio == NULL.
    no dev_t info for rq_abort,...,rq_requeue events if rq->rq_disk == NULL.

    This is mainly because we can't get the deivce from a request queue.
    But this may change in the future.

  - A packet command is converted to a string in TP_assign, not TP_print.
    While blktrace do the convertion just before output.

    Since pc requests should be rather rare, this is not a big issue.

  - In blktrace, an event can have 2 different print formats, but a TRACE_EVENT
    has a unique format, which means we have some unused data in a trace entry.

    The overhead is minimized by using __dynamic_array() instead of __array().

I've benchmarked the ioctl blktrace vs the splice based TRACE_EVENT tracing:

      dd                   dd + ioctl blktrace       dd + TRACE_EVENT (splice)
1     7.36s, 42.7 MB/s     7.50s, 42.0 MB/s          7.41s, 42.5 MB/s
2     7.43s, 42.3 MB/s     7.48s, 42.1 MB/s          7.43s, 42.4 MB/s
3     7.38s, 42.6 MB/s     7.45s, 42.2 MB/s          7.41s, 42.5 MB/s

So the overhead of tracing is very small, and no regression when using
those trace events vs blktrace.

And the binary output of TRACE_EVENT is much smaller than blktrace:

 # ls -l -h
 -rw-r--r-- 1 root root 8.8M 06-09 13:24 sda.blktrace.0
 -rw-r--r-- 1 root root 195K 06-09 13:24 sda.blktrace.1
 -rw-r--r-- 1 root root 2.7M 06-09 13:25 trace_splice.out

Following are some comparisons between TRACE_EVENT and blktrace:

plug:
  kjournald-480   [000]   303.084981: block_plug: [kjournald]
  kjournald-480   [000]   303.084981:   8,0    P   N [kjournald]

unplug_io:
  kblockd/0-118   [000]   300.052973: block_unplug_io: [kblockd/0] 1
  kblockd/0-118   [000]   300.052974:   8,0    U   N [kblockd/0] 1

remap:
  kjournald-480   [000]   303.085042: block_remap: 8,0 W 102736992 + 8 <- (8,8) 33384
  kjournald-480   [000]   303.085043:   8,0    A   W 102736992 + 8 <- (8,8) 33384

bio_backmerge:
  kjournald-480   [000]   303.085086: block_bio_backmerge: 8,0 W 102737032 + 8 [kjournald]
  kjournald-480   [000]   303.085086:   8,0    M   W 102737032 + 8 [kjournald]

getrq:
  kjournald-480   [000]   303.084974: block_getrq: 8,0 W 102736984 + 8 [kjournald]
  kjournald-480   [000]   303.084975:   8,0    G   W 102736984 + 8 [kjournald]

  bash-2066  [001]  1072.953770:   8,0    G   N [bash]
  bash-2066  [001]  1072.953773: block_getrq: 0,0 N 0 + 0 [bash]

rq_complete:
  konsole-2065  [001]   300.053184: block_rq_complete: 8,0 W () 103669040 + 16 [0]
  konsole-2065  [001]   300.053191:   8,0    C   W 103669040 + 16 [0]

  ksoftirqd/1-7   [001]  1072.953811:   8,0    C   N (5a 00 08 00 00 00 00 00 24 00) [0]
  ksoftirqd/1-7   [001]  1072.953813: block_rq_complete: 0,0 N (5a 00 08 00 00 00 00 00 24 00) 0 + 0 [0]

rq_insert:
  kjournald-480   [000]   303.084985: block_rq_insert: 8,0 W 0 () 102736984 + 8 [kjournald]
  kjournald-480   [000]   303.084986:   8,0    I   W 102736984 + 8 [kjournald]

Changelog from v2 -> v3:

- use the newly introduced __dynamic_array().

Changelog from v1 -> v2:

- use __string() instead of __array() to minimize the memory required
  to store hex dump of rq->cmd().

- support large pc requests.

- add missing blk_fill_rwbs_rq() in block_rq_requeue TRACE_EVENT.

- some cleanups.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A2DF669.5070905@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-09 12:34:23 -04:00
NeilBrown
0e6e0271a2 md/raid5: fix bug in reshape code when chunk_size decreases.
Now that we support changing the chunksize, we calculate
"reshape_sectors" to be the max of number of sectors in old
and new chunk size.
However there is one please where we still use 'chunksize'
rather than 'reshape_sectors'.
This causes a reshape that reduces the size of chunks to freeze.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-09 16:32:22 +10:00
NeilBrown
a8c906ca3f md/raid5 - avoid deadlocks in get_active_stripe during reshape
md has functionality to 'quiesce' and array so that all pending
IO completed and no new IO starts.  This is used to achieve a
stable state before making internal changes.

Currently this quiescing applies equally to normal IO, resync
IO, and reshape IO.
However there is a problem with applying it to reshape IO.
Reshape can have multiple 'stripe_heads' that must be active together.
If the quiesce come between allocating the first and the last of
such a collection, then we deadlock, as the last will not be allocated
until the quiesce is lifted, the quiesce will not be lifted until the
first (which has been allocated) gets used, and that first cannot be
used until the last is allocated.

It is not necessary to inhibit reshape IO when a quiesce is
requested.  Those places in the code that require a full quiesce will
ensure the reshape thread is not running at all.

So allow reshape requests to get access to new stripe_heads without
being blocked by a 'quiesce'.

This only affects in-place reshapes (i.e. where the array does not
grow or shrink) and these are only newly supported.  So this patch is
not needed in earlier kernels.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-09 14:39:59 +10:00
NeilBrown
f001a70cdc md/raid5: use conf->raid_disks in preference to mddev->raid_disk
mddev->raid_disks can be changed and any time by a request from
user-space.  It is a suggestion as to what number of raid_disks is
desired.

conf->raid_disks can only be changed by the raid5 module with suitable
locks in place.  It is a statement as to the current number of
raid_disks.

There are two places where the latter should be used, but the former
is used.  This can lead to a crash when reshaping an array.

This patch changes to mddev-> to conf->

Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-09 14:30:31 +10:00
Jens Axboe
9df1bb9b51 Revert "block: Fix bounce limit setting in DM"
This reverts commit a05c0205ba.

DM doesn't need to access the bounce_pfn directly.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-06-09 06:22:57 +02:00
Dan Williams
a08abd8ca8 async_tx: structify submission arguments, add scribble
Prepare the api for the arrival of a new parameter, 'scribble'.  This
will allow callers to identify scratchpad memory for dma address or page
address conversions.  As this adds yet another parameter, take this
opportunity to convert the common submission parameters (flags,
dependency, callback, and callback argument) into an object that is
passed by reference.

Also, take this opportunity to fix up the kerneldoc and add notes about
the relevant ASYNC_TX_* flags for each routine.

[ Impact: moves api pass-by-value parameters to a pass-by-reference struct ]

Signed-off-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-06-03 14:07:35 -07:00
Dan Williams
88ba2aa586 async_tx: kill ASYNC_TX_DEP_ACK flag
In support of inter-channel chaining async_tx utilizes an ack flag to
gate whether a dependent operation can be chained to another.  While the
flag is not set the chain can be considered open for appending.  Setting
the ack flag closes the chain and flags the descriptor for garbage
collection.  The ASYNC_TX_DEP_ACK flag essentially means "close the
chain after adding this dependency".  Since each operation can only have
one child the api now implicitly sets the ack flag at dependency
submission time.  This removes an unnecessary management burden from
clients of the api.

[ Impact: clean up and enforce one dependency per operation ]

Reviewed-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-06-03 14:07:34 -07:00
Martin K. Petersen
a05c0205ba block: Fix bounce limit setting in DM
blk_queue_bounce_limit() is more than a wrapper about the request queue
limits.bounce_pfn variable.  Introduce blk_queue_bounce_pfn() which can
be called by stacking drivers that wish to set the bounce limit
explicitly.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-06-03 09:33:18 +02:00
NeilBrown
ed37d83e6a md: raid5: change incorrect usage of 'min' macro to 'min_t'
A recent patch to raid5.c use min on an int and a sector_t.
This isn't allowed.
So change it to min_t(sector_t,x,y).

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-27 21:39:05 +10:00
NeilBrown
b492b852cd md: don't use locked_ioctl.
md has no need for the BKL - it does its own locking.
So md_ioctl doesn't need to be a locked_ioctl.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 12:57:36 +10:00
NeilBrown
7a91ee1f62 md: don't update curr_resync_completed without also updating reshape_position.
In order for the metadata to always be consistent, we mustn't updated
curr_resync_completed without also updating reshape_position.

The reshape code updates both at the same time.  However since
commit 97e4f42d62
the common md_do_sync will sometimes update curr_resync_completed
but is not in a position to update reshape_position.
So if MD_RECOVERY_RESHAPE is set (indicating that a reshape is
happening, so reshape_position might change), don't update
curr_resync_completed in md_do_sync, leave it to the per-personality
reshape code.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 12:57:21 +10:00
NeilBrown
848b318236 md: raid5: avoid sector values going negative when testing reshape progress.
As sector_t in unsigned, we cannot afford to let 'safepos' etc go
negative.
So replace
   a -= b;
by
   a -= min(b,a);

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 12:41:08 +10:00
NeilBrown
b6a9ce688f md: export 'frozen' resync state through sysfs
The md resync engine has a 'frozen' state which ensures that
no resync/recovery.  This is used to avoid races.

Export this state through the 'sync_action' sysfs attribute
so that user-space can benefit and also avoid some races.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 09:41:17 +10:00
NeilBrown
be51269103 md: bitmap: improve bitmap maintenance code.
The code for checking which bits in the bitmap can be cleared
has 2 problems:
 1/ it repeatedly takes and drops a spinlock, where it would make
    more sense to just hold on to it most of the time.
 2/ it doesn't make use of some opportunities to skip large sections
    of the bitmap

This patch fixes those.  It will only affect CPU consumption, not
correctness.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 09:41:17 +10:00
NeilBrown
2b69c83924 md: improve errno return when setting array_size
Instead of always returns EINVAL if anything goes wrong
when setting the array size, add the option of
  E2BIG
if the size requested is too large.  This makes it easier
for user-space to be sure what went wrong.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 09:41:17 +10:00
NeilBrown
62e1e389f8 md: always update level / chunk_size / layout when writing v1.x metadata.
We previously didn't update these fields when writing the metadata
because they could never change.  They can now, so we better write
them.
v0.90 metadata always updated these fields.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26 09:40:59 +10:00
Martin K. Petersen
ae03bf639a block: Use accessor functions for queue limits
Convert all external users of queue limits to using wrapper functions
instead of poking the request queue variables directly.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22 23:22:54 +02:00
Martin K. Petersen
e1defc4ff0 block: Do away with the notion of hardsect_size
Until now we have had a 1:1 mapping between storage device physical
block size and the logical block sized used when addressing the device.
With SATA 4KB drives coming out that will no longer be the case.  The
sector size will be 4KB but the logical block size will remain
512-bytes.  Hence we need to distinguish between the physical block size
and the logical ditto.

This patch renames hardsect_size to logical_block_size.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22 23:22:54 +02:00
Ingo Molnar
1079cac0f4 Merge commit 'v2.6.30-rc6' into tracing/core
Merge reason: we were on an -rc4 base, sync up to -rc6

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-18 10:15:35 +02:00
Ingo Molnar
44347d947f Merge branch 'linus' into tracing/core
Merge reason: tracing/core was on a .30-rc1 base and was missing out on
              on a handful of tracing fixes present in .30-rc5-almost.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-07 11:17:34 +02:00
NeilBrown
c4647292fd md: remove rd%d links immediately after stopping an array.
md maintains link in sys/mdXX/md/ to identify which device has
which role in the array. e.g.
   rd2 -> dev-sda

indicates that the device with role '2' in the array is sda.

These links are only present when the array is active.  They are
created immediately after ->run is called, and so should be removed
immediately after ->stop is called.
However they are currently removed a little bit later, and it is
possible for ->run to be called again, thus adding these links, before
they are removed.

So move the removal earlier so they are consistently only present when
the array is active.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07 12:51:06 +10:00
NeilBrown
5bf2959754 md: remove ability to explicit set an inactive array to 'clean'.
Being able to write 'clean' to an 'array_state' of an inactive array
to activate it in 'clean' mode is both unnecessary and inconvenient.

It is unnecessary because the same can be achieved by writing
'active'.  This activates and array, but it still remains 'clean'
until the first write.

It is inconvenient because writing 'clean' is more often used to
cause an 'active' array to revert to 'clean' mode (thus blocking
any writes until a 'write-pending' is promoted to 'active').

Allowing 'clean' to both activate an array and mark an active array as
clean can lead to races:  One program writes 'clean' to mark the
active array as clean at the same time as another program writes
'inactive' to deactivate (stop) and active array.  Depending on which
writes first, the array could be deactivated and immediately
reactivated which isn't what was desired.

So just disable the use of 'clean' to activate an array.

This avoids a race that can be triggered with mdadm-3.0 and external
metadata, so it suitable for -stable.

Reported-by: Rafal Marszewski <rafal.marszewski@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07 12:50:57 +10:00
Jan Engelhardt
110518bccf md: constify VFTs
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07 12:49:37 +10:00
NeilBrown
dd71cf6b27 md: tidy up status_resync to handle large arrays.
Two problems in status_resync.
1/ It still used Kilobytes as the basic block unit, while most code
   now uses sectors uniformly.
2/ It doesn't allow for the possibility that max_sectors exceeds
   the range of "unsigned long".

So
 - change "max_blocks" to "max_sectors", and store sector numbers
   in there and in 'resync'
 - Make 'rt' a 'sector_t' so it can temporarily hold the number of
   remaining sectors.
 - use sector_div rather than normal division.
 - change the magic '100' used to preserve precision to '32'.
   + making it a power of 2 makes division easier
   + it doesn't need to be as large as it was chosen when we averaged
     speed over the entire run.  Now we average speed over the last 30
     seconds or so.

Reported-by: "Mario 'BitKoenig' Holbe" <Mario.Holbe@TU-Ilmenau.DE>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07 12:49:35 +10:00
NeilBrown
db305e507d md: fix some (more) errors with bitmaps on devices larger than 2TB.
If a write intent bitmap covers more than 2TB, we sometimes work with
values beyond 32bit, so these need to be sector_t.  This patches
add the required casts to some unsigned longs that are being shifted
up.

This will affect any raid10 larger than 2TB, or any raid1/4/5/6 with
member devices that are larger than 2TB.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: "Mario 'BitKoenig' Holbe" <Mario.Holbe@TU-Ilmenau.DE>
Cc: stable@kernel.org
2009-05-07 12:49:06 +10:00
NeilBrown
1805556912 md/raid10: don't clear bitmap during recovery if array will still be degraded.
If we have a raid10 with multiple missing devices, and we recover just
one of these to a spare, then we risk (depending on the bitmap and
array chunk size) clearing bits of the bitmap for which recovery isn't
complete (because a device is still missing).

This can lead to a subsequent "re-add" being recovered without
any IO happening, which would result in loss of data.

This patch takes the safe approach of not clearing bitmap bits
if the array will still be degraded.

This patch is suitable for all active -stable kernels.

Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07 12:48:10 +10:00
NeilBrown
b74fd2826c md: fix loading of out-of-date bitmap.
When md is loading a bitmap which it knows is out of date, it fills
each page with 1s and writes it back out again.  However the
write_page call makes used of bitmap->file_pages and
bitmap->last_page_size which haven't been set correctly yet.  So this
can sometimes fail.

Move the setting of file_pages and last_page_size to before the call
to write_page.

This bug can cause the assembly on an array to fail, thus making the
data inaccessible.  Hence I think it is a suitable candidate for
-stable.

Cc: stable@kernel.org
Reported-by: Vojtech Pavlik <vojtech@suse.cz>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07 12:47:19 +10:00
Alan D. Brunelle
22a7c31a96 blktrace: from-sector redundant in trace_block_remap
Remove redundant from-sector parameter: it's /always/ the bio's sector
passed in.

[ Impact: cleanup ]

Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <49FF517C.7000503@hp.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-06 14:13:01 +02:00
Linus Torvalds
2edbdd1266 Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
  md: support bitmaps on RAID10 arrays larger then 2 terabytes
  md: update sync_completed and reshape_position even more often.
  md: improve usefulness and accuracy of sysfs file md/sync_completed.
  md: allow setting newly added device to 'in_sync' via sysfs.
  md: tiny md.h cleanups
2009-04-20 08:37:37 -07:00
NeilBrown
1f59390339 md: support bitmaps on RAID10 arrays larger then 2 terabytes
.. and other arrays with components larger than 2 terabytes.

We use a "long" rather than a "sector_t" in part of the bitmap
size calculations, which is sad.

Reported-by: "Mario 'BitKoenig' Holbe" <Mario.Holbe@TU-Ilmenau.DE>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-20 11:50:24 +10:00
NeilBrown
c03f6a1969 md: update sync_completed and reshape_position even more often.
There are circumstances when a user-space process might need to
"oversee" a resync/reshape process.  For example when doing an
in-place reshape of a raid5, it is prudent to take a backup of each
section before reshaping it as this is the only way to provide
safety against an unplanned shutdown (i.e. crash/power failure).

The sync_max sysfs value can be used to stop the resync from
advancing beyond a particular point.
So user-space can:
  suspend IO to the first section and back it up
  set 'sync_max' to the end of the section
  wait for 'sync_completed' to reach that point
  resume IO on the first section and move on to the next section.

However this process requires the kernel and user-space to run in
lock-step which could introduce unnecessary delays.

It would be better if a 'double buffered' approach could be used with
userspace and kernel space working on different sections with the
'next' section always ready when the 'current' section is finished.

One problem with implementing this is that sync_completed is only
guaranteed to be updated when the sync process reaches sync_max.
(it is updated on a time basis at other times, but it is hard to rely
on that).  This defeats some of the double buffering.

With this patch, sync_completed (and reshape_position) get updated as
the current position approaches sync_max, so there is room for
userspace to advance sync_max early without losing updates.

To be precise, sync_completed is updated when the current sync
position reaches half way between the current value of sync_completed
and the value of sync_max.  This will usually be a good time for user
space to update sync_max.

If sync_max does not get updated, the updates to sync_completed
(together with associated metadata updates) will occur at an
exponentially increasing frequency which will get unreasonably fast
(one update every page) immediately before the process hits sync_max
and stops.  So the update rate will be unreasonably fast only for an
insignificant period of time.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-17 11:06:30 +10:00
Christoph Hellwig
8f3d8ba20e block: move bio list helpers into bio.h
It's used by DM and MD and generally useful, so move the bio list
helpers into bio.h.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15 08:28:09 +02:00
NeilBrown
acb180b0e3 md: improve usefulness and accuracy of sysfs file md/sync_completed.
The sync_completed file reports how much of a resync (or recovery or
reshape) has been completed.
However due to the possibility of out-of-order completion of writes,
it is not certain to be accurate.

We have an internal value - mddev->curr_resync_completed - which is an
accurate value (though it might not always be quite so uptodate).

So:
 - make curr_resync_completed be uptodate a little more often,
   particularly when raid5 reshape updates status in the metadata
 - report curr_resync_completed in the sysfs file
 - allow poll/select to report all updates to md/sync_completed.

This makes sync_completed completed usable by any external metadata
handler that wants to record this status information in its metadata.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-14 16:28:34 +10:00
NeilBrown
6d56e27844 md: allow setting newly added device to 'in_sync' via sysfs.
When adding devices to an active array via sysfs, there is currently
no way to mark a device as 'in-sync' which is useful when
incrementally assembling an array.

So add that option.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-14 12:01:57 +10:00
Christoph Hellwig
63fe08177f md: tiny md.h cleanups
- update inclusion guard and make sure it covers the whole file
 - remove superflous #ifdef CONFIG_BLOCK
 - make sure all required headers are included so that new users aren't
   required to include others before

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-14 12:01:53 +10:00
Mikulas Patocka
340cd44451 dm kcopyd: fix callback race
If the thread calling dm_kcopyd_copy is delayed due to scheduling inside
split_job/segment_complete and the subjobs complete before the loop in
split_job completes, the kcopyd callback could be invoked from the
thread that called dm_kcopyd_copy instead of the kcopyd workqueue.

dm_kcopyd_copy -> split_job -> segment_complete -> job->fn()

Snapshots depend on the fact that callbacks are called from the singlethreaded
kcopyd workqueue and expect that there is no racing between individual
callbacks. The racing between callbacks can lead to corruption of exception
store and it can also mean that exception store callbacks are called twice
for the same exception - a likely reason for crashes reported inside
pending_complete() / remove_exception().

This patch fixes two problems:

1. job->fn being called from the thread that submitted the job (see above).

- Fix: hand over the completion callback to the kcopyd thread.

2. job->fn(read_err, write_err, job->context); in segment_complete
reports the error of the last subjob, not the union of all errors.

- Fix: pass job->write_err to the callback to report all error bits
  (it is done already in run_complete_job)

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-04-09 00:27:17 +01:00
Mikulas Patocka
73830857bc dm kcopyd: prepare for callback race fix
Use a variable in segment_complete() to point to the dm_kcopyd_client
struct and only release job->pages in run_complete_job() if any are
defined.  These changes are needed by the next patch.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-04-09 00:27:16 +01:00
Mikulas Patocka
af7e466a1a dm: implement basic barrier support
Barriers are submitted to a worker thread that issues them in-order.

The thread is modified so that when it sees a barrier request it waits
for all pending IO before the request then submits the barrier and
waits for it.  (We must wait, otherwise it could be intermixed with
following requests.)

Errors from the barrier request are recorded in a per-device barrier_error
variable. There may be only one barrier request in progress at once.

For now, the barrier request is converted to a non-barrier request when
sending it to the underlying device.

This patch guarantees correct barrier behavior if the underlying device
doesn't perform write-back caching. The same requirement existed before
barriers were supported in dm.

Bottom layer barrier support (sending barriers by target drivers) and
handling devices with write-back caches will be done in further patches.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-04-09 00:27:16 +01:00
Mikulas Patocka
92c639021c dm: remove dm_request loop
Remove queue_io return value and a loop in dm_request.

IO may be submitted to a worker thread with queue_io().  queue_io() sets
DMF_QUEUE_IO_TO_THREAD so that all further IO is queued for the thread. When
the thread finishes its work, it clears DMF_QUEUE_IO_TO_THREAD and from this
point on, requests are submitted from dm_request again. This will be used
for processing barriers.

Remove the loop in dm_request. queue_io() can submit I/Os to the worker thread
even if DMF_QUEUE_IO_TO_THREAD was not set.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-04-09 00:27:15 +01:00
Mikulas Patocka
3b00b2036f dm: rework queueing and suspension
Rework shutting down on suspend and document the associated rules.

Drop write lock in __split_and_process_bio to allow more processing
concurrency.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-04-09 00:27:15 +01:00
Alasdair G Kergon
54d9a1b451 dm: simplify dm_request loop
Refactor the code in dm_request().

Require the new DMF_BLOCK_FOR_SUSPEND flag on readahead bios we will
discard so we don't drop such bios while processing a barrier.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-04-09 00:27:14 +01:00