Commit Graph

461 Commits

Author SHA1 Message Date
NeilBrown
c4796e215f md/raid10: another memory leak due to reshape.
Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-14 13:08:28 +11:00
NeilBrown
3fd83717e4 md: use set_bit/clear_bit instead of shift/mask for bi_flags changes.
Using {set,clear}_bit is more consistent than shifting and masking.

No functional change.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-10-09 10:07:04 +11:00
NeilBrown
cb8b12b5d8 md/raid10: always initialise ->state on newly allocated r10_bio
Most places which allocate an r10_bio zero the ->state, some don't.
As the r10_bio comes from a mempool, and the allocation function uses
kzalloc it is often zero anyway.  But sometimes it isn't and it is
best to be safe.

I only noticed this because of the bug fixed by an earlier patch
where the r10_bios allocated for a reshape were left around to
be used by a subsequent resync.  In that case the R10BIO_IsReshape
flag caused problems.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-19 17:20:27 +10:00
NeilBrown
e337aead3a md/raid10: avoid memory leak on error path during reshape.
If raid10 reshape fails to find somewhere to read a block
from, it returns without freeing memory...

Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-19 17:20:27 +10:00
NeilBrown
b39685526f md/raid10: Fix memory leak when raid10 reshape completes.
When a raid10 commences a resync/recovery/reshape it allocates
some buffer space.
When a resync/recovery completes the buffer space is freed.  But not
when the reshape completes.
This can result in a small memory leak.

There is a subtle side-effect of this bug.  When a RAID10 is reshaped
to a larger array (more devices), the reshape is immediately followed
by a "resync" of the new space.  This "resync" will use the buffer
space which was allocated for "reshape".  This can cause problems
including a "BUG" in the SCSI layer.  So this is suitable for -stable.

Cc: stable@vger.kernel.org (v3.5+)
Fixes: 3ea7daa5d7
Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-19 17:20:27 +10:00
NeilBrown
ce0b0a4695 md/raid10: fix memory leak when reshaping a RAID10.
raid10 reshape clears unwanted bits from a bio->bi_flags using
a method which, while clumsy, worked until 3.10 when BIO_OWNS_VEC
was added.
Since then it clears that bit but shouldn't.  This results in a
memory leak.

So change to used the approved method of clearing unwanted bits.

As this causes a memory leak which can consume all of memory
the fix is suitable for -stable.

Fixes: a38352e0ac
Cc: stable@vger.kernel.org (v3.10+)
Reported-by: mdraid.pkoch@dfgh.net (Peter Koch)
Signed-off-by: NeilBrown <neilb@suse.de>
2014-08-19 17:20:27 +10:00
NeilBrown
2446dba03f md/raid1,raid10: always abort recover on write error.
Currently we don't abort recovery on a write error if the write error
to the recovering device was triggerd by normal IO (as opposed to
recovery IO).

This means that for one bitmap region, the recovery might write to the
recovering device for a few sectors, then not bother for subsequent
sectors (as it never writes to failed devices).  In this case
the bitmap bit will be cleared, but it really shouldn't.

The result is that if the recovering device fails and is then re-added
(after fixing whatever hardware problem triggerred the failure),
the second recovery won't redo the region it was in the middle of,
so some of the device will not be recovered properly.

If we abort the recovery, the region being processes will be cancelled
(bit not cleared) and the whole region will be retried.

As the bug can result in data corruption the patch is suitable for
-stable.  For kernels prior to 3.11 there is a conflict in raid10.c
which will require care.

Original-from: jiao hui <jiaohui@bwstor.com.cn>
Reported-and-tested-by: jiao hui <jiaohui@bwstor.com.cn>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@vger.kernel.org
2014-07-31 10:16:52 +10:00
NeilBrown
cc13b1d150 md/raid10: call wait_barrier() for each request submitted.
wait_barrier() includes a counter, so we must call it precisely once
(unless balanced by allow_barrier()) for each request submitted.

Since
commit 20d0189b10
    block: Introduce new bio_split()
in 3.14-rc1, we don't call it for the extra requests generated when
we need to split a bio.

When this happens the counter goes negative, any resync/recovery will
never start, and  "mdadm --stop" will hang.

Reported-by: Chris Murphy <lists@colorremedies.com>
Fixes: 20d0189b10
Cc: stable@vger.kernel.org (3.14+)
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2014-05-06 09:49:26 +10:00
Linus Torvalds
f568849eda Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block
Pull core block IO changes from Jens Axboe:
 "The major piece in here is the immutable bio_ve series from Kent, the
  rest is fairly minor.  It was supposed to go in last round, but
  various issues pushed it to this release instead.  The pull request
  contains:

   - Various smaller blk-mq fixes from different folks.  Nothing major
     here, just minor fixes and cleanups.

   - Fix for a memory leak in the error path in the block ioctl code
     from Christian Engelmayer.

   - Header export fix from CaiZhiyong.

   - Finally the immutable biovec changes from Kent Overstreet.  This
     enables some nice future work on making arbitrarily sized bios
     possible, and splitting more efficient.  Related fixes to immutable
     bio_vecs:

        - dm-cache immutable fixup from Mike Snitzer.
        - btrfs immutable fixup from Muthu Kumar.

  - bio-integrity fix from Nic Bellinger, which is also going to stable"

* 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits)
  xtensa: fixup simdisk driver to work with immutable bio_vecs
  block/blk-mq-cpu.c: use hotcpu_notifier()
  blk-mq: for_each_* macro correctness
  block: Fix memory leak in rw_copy_check_uvector() handling
  bio-integrity: Fix bio_integrity_verify segment start bug
  block: remove unrelated header files and export symbol
  blk-mq: uses page->list incorrectly
  blk-mq: use __smp_call_function_single directly
  btrfs: fix missing increment of bi_remaining
  Revert "block: Warn and free bio if bi_end_io is not set"
  block: Warn and free bio if bi_end_io is not set
  blk-mq: fix initializing request's start time
  block: blk-mq: don't export blk_mq_free_queue()
  block: blk-mq: make blk_sync_queue support mq
  block: blk-mq: support draining mq queue
  dm cache: increment bi_remaining when bi_end_io is restored
  block: fixup for generic bio chaining
  block: Really silence spurious compiler warnings
  block: Silence spurious compiler warnings
  block: Kill bio_pair_split()
  ...
2014-01-30 11:19:05 -08:00
NeilBrown
0b59bb6422 md/raid10: avoid fullsync when not necessary.
This is the raid10 equivalent of

commit 4f0a5e012c
    MD RAID1: Further conditionalize 'fullsync'

If a device in a newly assembled array is not fully recovered we
currently do a fully resync by don't need to.

Signed-off-by: NeilBrown <neilb@suse.de>
2014-01-14 16:44:21 +11:00
NeilBrown
e8b8491585 md/raid10: fix bug when raid10 recovery fails to recover a block.
commit e875ecea26
    md/raid10 record bad blocks as needed during recovery.

added code to the "cannot recover this block" path to record a bad
block rather than fail the whole recovery.
Unfortunately this new case was placed *after* r10bio was freed rather
than *before*, yet it still uses r10bio.
This is will crash with a null dereference.

So move the freeing of r10bio down where it is safe.

Cc: stable@vger.kernel.org (v3.1+)
Fixes: e875ecea26
Reported-by: Damian Nowak <spam@nowaker.net>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181
Signed-off-by: NeilBrown <neilb@suse.de>
2014-01-14 16:44:08 +11:00
NeilBrown
b50c259e25 md/raid10: fix two bugs in handling of known-bad-blocks.
If we discover a bad block when reading we split the request and
potentially read some of it from a different device.

The code path of this has two bugs in RAID10.
1/ we get a spin_lock with _irq, but unlock without _irq!!
2/ The calculation of 'sectors_handled' is wrong, as can be clearly
   seen by comparison with raid1.c

This leads to at least 2 warnings and a probable crash is a RAID10
ever had known bad blocks.

Cc: stable@vger.kernel.org (v3.1+)
Fixes: 856e08e237
Reported-by: Damian Nowak <spam@nowaker.net>
URL: https://bugzilla.kernel.org/show_bug.cgi?id=68181
Signed-off-by: NeilBrown <neilb@suse.de>
2014-01-14 16:44:07 +11:00
Kent Overstreet
20d0189b10 block: Introduce new bio_split()
The new bio_split() can split arbitrary bios - it's not restricted to
single page bios, like the old bio_split() (previously renamed to
bio_pair_split()). It also has different semantics - it doesn't allocate
a struct bio_pair, leaving it up to the caller to handle completions.

Then convert the existing bio_pair_split() users to the new bio_split()
- and also nvme, which was open coding bio splitting.

(We have to take that BUG_ON() out of bio_integrity_trim() because this
bio_split() needs to use it, and there's no reason it has to be used on
bios marked as cloned; BIO_CLONED doesn't seem to have clearly
documented semantics anyways.)

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Neil Brown <neilb@suse.de>
2013-11-23 22:33:57 -08:00
Kent Overstreet
ee67891bf1 block: Rename bio_split() -> bio_pair_split()
This is prep work for introducing a more general bio_split().

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: NeilBrown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Sage Weil <sage@inktank.com>
2013-11-23 22:33:56 -08:00
Kent Overstreet
458b76ed2f block: Kill bio_segments()/bi_vcnt usage
When we start sharing biovecs, keeping bi_vcnt accurate for splits is
going to be error prone - and unnecessary, if we refactor some code.

So bio_segments() has to go - but most of the existing users just needed
to know if the bio had multiple segments, which is easier - add a
bio_multiple_segments() for them.

(Two of the current uses of bio_segments() are going to go away in a
couple patches, but the current implementation of bio_segments() is
unsafe as soon as we start doing driver conversions for immutable
biovecs - so implement a dumb version for bisectability, it'll go away
in a couple patches)

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Nagalakshmi Nandigama <Nagalakshmi.Nandigama@lsi.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
2013-11-23 22:33:51 -08:00
Kent Overstreet
4f024f3797 block: Abstract out bvec iterator
Immutable biovecs are going to require an explicit iterator. To
implement immutable bvecs, a later patch is going to add a bi_bvec_done
member to this struct; for now, this patch effectively just renames
things.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@inktank.com>
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris <josh.h.morris@us.ibm.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: Benny Halevy <bhalevy@tonian.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Ben Myers <bpm@sgi.com>
Cc: xfs@oss.sgi.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchand@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Peng Tao <tao.peng@emc.com>
Cc: Andy Adamson <andros@netapp.com>
Cc: fanchaoting <fanchaoting@cn.fujitsu.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Pankaj Kumar <pankaj.km@samsung.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Mel Gorman <mgorman@suse.de>6
2013-11-23 22:33:47 -08:00
Linus Torvalds
6d6e352c80 md update for 3.13.
Mostly optimisations and obscure bug fixes.
  - raid5 gets less lock contention
  - raid1 gets less contention between normal-io and resync-io
    during resync.
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Merge tag 'md/3.13' of git://neil.brown.name/md

Pull md update from Neil Brown:
 "Mostly optimisations and obscure bug fixes.
   - raid5 gets less lock contention
   - raid1 gets less contention between normal-io and resync-io during
     resync"

* tag 'md/3.13' of git://neil.brown.name/md:
  md/raid5: Use conf->device_lock protect changing of multi-thread resources.
  md/raid5: Before freeing old multi-thread worker, it should flush them.
  md/raid5: For stripe with R5_ReadNoMerge, we replace REQ_FLUSH with REQ_NOMERGE.
  UAPI: include <asm/byteorder.h> in linux/raid/md_p.h
  raid1: Rewrite the implementation of iobarrier.
  raid1: Add some macros to make code clearly.
  raid1: Replace raise_barrier/lower_barrier with freeze_array/unfreeze_array when reconfiguring the array.
  raid1: Add a field array_frozen to indicate whether raid in freeze state.
  md: Convert use of typedef ctl_table to struct ctl_table
  md/raid5: avoid deadlock when raid5 array has unack badblocks during md_stop_writes.
  md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread.
  md: fix some places where mddev_lock return value is not checked.
  raid5: Retry R5_ReadNoMerge flag when hit a read error.
  raid5: relieve lock contention in get_active_stripe()
  raid5: relieve lock contention in get_active_stripe()
  wait: add wait_event_cmd()
  md/raid5.c: add proper locking to error path of raid5_start_reshape.
  md: fix calculation of stacking limits on level change.
  raid5: Use slow_path to release stripe when mddev->thread is null
2013-11-20 13:05:25 -08:00
NeilBrown
c91abf5a35 md: use MD_RECOVERY_INTR instead of kthread_should_stop in resync thread.
We currently use kthread_should_stop() in various places in the
sync/reshape code to abort early.
However some places set MD_RECOVERY_INTR but don't immediately call
md_reap_sync_thread() (and we will shortly get another one).
When this happens we are relying on md_check_recovery() to reap the
thread and that only happen when it finishes normally.
So MD_RECOVERY_INTR must lead to a normal finish without the
kthread_should_stop() test.

So replace all relevant tests, and be more careful when the thread is
interrupted not to acknowledge that latest step in a reshape as it may
not be fully committed yet.

Also add a test on MD_RECOVERY_INTR in the 'is_mddev_idle' loop
so we don't wait have to wait for the speed to drop before we can abort.

Signed-off-by: NeilBrown <neilb@suse.de>
2013-11-19 15:19:17 +11:00
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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