dm_create_error_table() was added in kernel 2.6.18 and never used...
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
void returning functions returned the return value of another void
returning function...
Spotted by sparse.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Remove an avoidable 3ms delay on some dm-raid1 and kcopyd I/O.
It is specified that any submitted bio without BIO_RW_SYNC flag may plug the
queue (i.e. block the requests from being dispatched to the physical device).
The queue is unplugged when the caller calls blk_unplug() function. Usually, the
sequence is that someone calls submit_bh to submit IO on a buffer. The IO plugs
the queue and waits (to be possibly joined with other adjacent bios). Then, when
the caller calls wait_on_buffer(), it unplugs the queue and submits the IOs to
the disk.
This was happenning:
When doing O_SYNC writes, function fsync_buffers_list() submits a list of
bios to dm_raid1, the bios are added to dm_raid1 write queue and kmirrord is
woken up.
fsync_buffers_list() calls wait_on_buffer(). That unplugs the queue, but
there are no bios on the device queue as they are still in the dm_raid1 queue.
wait_on_buffer() starts waiting until the IO is finished.
kmirrord is scheduled, kmirrord takes bios and submits them to the devices.
The submitted bio plugs the harddisk queue but there is no one to unplug it.
(The process that called wait_on_buffer() is already sleeping.)
So there is a 3ms timeout, after which the queues on the harddisks are
unplugged and requests are processed.
This 3ms timeout meant that in certain workloads (e.g. O_SYNC, 8kb writes),
dm-raid1 is 10 times slower than md raid1.
Every time we submit something asynchronously via dm_io, we must unplug the
queue actually to send the request to the device.
This patch adds an unplug call to kmirrord - while processing requests, it keeps
the queue plugged (so that adjacent bios can be merged); when it finishes
processing all the bios, it unplugs the queue to submit the bios.
It also fixes kcopyd which has the same potential problem. All kcopyd requests
are submitted with BIO_RW_SYNC.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
This patch replaces the schedule() in the main kmirrord thread with a timer.
The schedule() could introduce an unwanted delay when work is ready to be
processed.
The code instead calls wake() when there's work to be done immediately, and
delayed_wake() after a failure to give a short delay before retrying.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Remove client counting code that is no longer needed.
Initialization and destruction is made globally from dm_init and dm_exit and is
not based on client counts. Initialization allocates only one empty slab cache,
so there is no negative impact from performing the initialization always,
regardless of whether some client uses kcopyd or not.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Change the global mempool in kcopyd into a per-device mempool to avoid
deadlock possibilities.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Remove internal module reference fields from the interface.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Clean up the dm-log interface to prepare for publishing it in include/linux.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Clean up the kcopyd interface to prepare for publishing it in include/linux.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Clean up the dm-io interface to prepare for publishing it in include/linux.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Save pointer to dm_target in dm_snapshot structure.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move the dirty region log code into a separate module so
other targets can share the code.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Change dm-log.c messages from "mirror log" to "dirty region log" as
a new dm target wants to share this code.
Signed-off-by: Heinz Mauelshagen <hjm@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Limit the amount of memory allocated per snapshot on systems
with a large page size. (The larger default chunk size on
these systems compensates for the smaller number of pages reserved.)
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
If a snapshot has a smaller chunksize than the page size the
conversion to pages currently returns 0 instead of 1, causing:
kernel BUG in mempool_resize.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: stable@kernel.org
drivers/md/*.[ch] contains only one more printk line with a trailing space.
Remove it.
Signed-off-by: Nick Andrew <nick@nick-andrew.net>
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
If a failure is detected after a parity check operation has been initiated,
but before it completes handle_parity_checks5 will never quiesce operations on
the stripe.
Explicitly handle this case by "canceling" the parity check, i.e. clear the
STRIPE_OP_CHECK flags and queue the stripe on the handle list again to refresh
any non-uptodate blocks.
Kernel versions >= 2.6.23 are susceptible.
Cc: <stable@kernel.org>
Cc: NeilBrown <neilb@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
write_err is an unsigned long used with set_bit() so should not be passed
around as unsigned int.
http://bugzilla.kernel.org/show_bug.cgi?id=10271
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix regression in dm-crypt introduced in commit
3a7f6c990a ("dm crypt: use async crypto").
If write requests need to be split into pieces, the code must not process them
in parallel because the crypto context cannot be shared. So there can be
parallel crypto operations on one part of the write, but only one write bio
can be processed at a time.
This is not optimal and the workqueue code needs to be optimized for parallel
processing, but for now it solves the problem without affecting the
performance of synchronous crypto operation (most of current dm-crypt users).
http://bugzilla.kernel.org/show_bug.cgi?id=10242http://bugzilla.kernel.org/show_bug.cgi?id=10207
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
gcc-3.4.5 on sparc64:
drivers/md/raid5.c: In function `raid5_end_read_request':
drivers/md/raid5.c:1147: warning: long long unsigned int format, long unsigned int arg (arg 4)
drivers/md/raid5.c:1164: warning: long long unsigned int format, long unsigned int arg (arg 3)
drivers/md/raid5.c:1170: warning: long long unsigned int format, long unsigned int arg (arg 3)
sector_t is u64, and we don't know what type the architecture uses to
implement u64 (on some it is unsigned long).
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Exposing the binary blob which is the md 'super-block' via sysfs doesn't
really fit with the whole sysfs model, and ever since commit
8118a859dc ("sysfs: fix off-by-one error
in fill_read_buffer()") it doesn't actually work at all (as the size of
the blob is often one page).
(akpm: as in, fs/sysfs/file.c:fill_read_buffer() goes BUG)
So just remove it altogether. It isn't really useful.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recent patch titled
Reduce CPU wastage on idle md array with a write-intent bitmap.
would sometimes leave the array with dirty bitmap bits that stay dirty. A
subsequent write would sort things out so it isn't a big problem, but should
be fixed nonetheless.
We need to make sure that when the bitmap becomes not "allclean", the
daemon_sleep really does get set to a sensible value.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If an md array is "auto-read-only", then this appears in /proc/mdstat as
/dev/md0: active(auto-read-only)
whereas if it is truely readonly, it appears as
/dev/md0: active (read-only)
The difference being a space.
One program known to parse this file expects the space and gets badly
confused. It will be fixed, but it would be best if what the kernel generates
is more consistent too.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This message describes another issue about md RAID10 found by testing the
2.6.24 md RAID10 using new scsi fault injection framework.
Abstract:
When a scsi error results in disabling a disk during RAID10 recovery, the
resync threads of md RAID10 could stall.
This case, the raid array has already been broken and it may not matter. But
I think stall is not preferable. If it occurs, even shutdown or reboot will
fail because of resource busy.
The deadlock mechanism:
The r10bio_s structure has a "remaining" member to keep track of BIOs yet to
be handled when recovering. The "remaining" counter is incremented when
building a BIO in sync_request() and is decremented when finish a BIO in
end_sync_write().
If building a BIO fails for some reasons in sync_request(), the "remaining"
should be decremented if it has already been incremented. I found a case
where this decrement is forgotten. This causes a md_do_sync() deadlock
because md_do_sync() waits for md_done_sync() called by end_sync_write(), but
end_sync_write() never calls md_done_sync() because of the "remaining" counter
mismatch.
For example, this problem would be reproduced in the following case:
Personalities : [raid10]
md0 : active raid10 sdf1[4] sde1[5](F) sdd1[2] sdc1[1] sdb1[6](F)
3919616 blocks 64K chunks 2 near-copies [4/2] [_UU_]
[>....................] recovery = 2.2% (45376/1959808) finish=0.7min speed=45376K/sec
This case, sdf1 is recovering, sdb1 and sde1 are disabled.
An additional error with detaching sdd will cause a deadlock.
md0 : active raid10 sdf1[4] sde1[5](F) sdd1[6](F) sdc1[1] sdb1[7](F)
3919616 blocks 64K chunks 2 near-copies [4/1] [_U__]
[=>...................] recovery = 5.0% (99520/1959808) finish=5.9min speed=5237K/sec
2739 ? S< 0:17 [md0_raid10]
28608 ? D< 0:00 [md0_resync]
28629 pts/1 Ss 0:00 bash
28830 pts/1 R+ 0:00 ps ax
31819 ? D< 0:00 [kjournald]
The resync thread keeps working, but actually it is deadlocked.
Patch:
By this patch, the remaining counter will be decremented if needed.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Thanks to K.Tanaka and the scsi fault injection framework, here is a fix for
another possible deadlock in raid1/raid10 error handing.
If a read request returns an error while a resync is happening and a resync
request is pending, the attempt to fix the error will block until the resync
progresses, and the resync will block until the read request completes. Thus
a deadlock.
This patch fixes the problem.
Cc: "K.Tanaka" <k-tanaka@ce.jp.nec.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch changes the disk to be read for layout "far > 1" to always be the
disk with the lowest block address.
Thus the chunks to be read will always be (for a fully functioning array) from
the first band of stripes, and the raid will then work as a raid0 consisting
of the first band of stripes.
Some advantages:
The fastest part which is the outer sectors of the disks involved will be
used. The outer blocks of a disk may be as much as 100 % faster than the
inner blocks.
Average seek time will be smaller, as seeks will always be confined to the
first part of the disks.
Mixed disks with different performance characteristics will work better, as
they will work as raid0, the sequential read rate will be number of disks
involved times the IO rate of the slowest disk.
If a disk is malfunctioning, the first disk which is working, and has the
lowest block address for the logical block will be used.
Signed-off-by: Keld Simonsen <keld@dkuug.dk>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we access attributes of an rdev (component device on an md array) through
sysfs, we really need to lock the array against concurrent changes. We
currently do that when we change an attribute, but not when we read an
attribute. We need to lock when reading as well else rdev->mddev could become
NULL while we are accessing it.
So add appropriate locking (mddev_lock) to rdev_attr_show.
rdev_size_store requires some extra care as well as it needs to unlock the
mddev while scanning other mddevs for overlapping regions. We currently
assume that rdev->mddev will still be unchanged after the scan, but that
cannot be certain. So take a copy of rdev->mddev for use at the end of the
function.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A resync/reshape/recovery thread will refuse to progress when the array is
marked read-only. So whenever it mark it not read-only, it is important to
wake up thread resync thread. There is one place we didn't do this.
The problem manifests if the start_ro module parameters is set, and a raid5
array that is in the middle of a reshape (restripe) is started. The array
will initially be semi-read-only (meaning it acts like it is readonly until
the first write). So the reshape will not proceed.
On the first write, the array will become read-write, but the reshape will not
be started, and there is no event which will ever restart that thread.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a raid1 array is stopped, all components currently get added to the list
for auto-detection. However we should really only add components that were
found by autodetection in the first place. So add a flag to record that
information, and use it.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make sure the data doesn't start before the end of the superblock when the
superblock is at the start of the device.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On an md array with a write-intent bitmap, a thread wakes up every few seconds
and scans the bitmap looking for work to do. If the array is idle, there will
be no work to do, but a lot of scanning is done to discover this.
So cache the fact that the bitmap is completely clean, and avoid scanning the
whole bitmap when the cache is known to be clean.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When handling a read error, we freeze the array to stop any other IO while
attempting to over-write with correct data.
This is done in the raid1d(raid10d) thread and must wait for all submitted IO
to complete (except for requests that failed and are sitting in the retry
queue - these are counted in ->nr_queue and will stay there during a freeze).
However write requests need attention from raid1d as bitmap updates might be
required. This can cause a deadlock as raid1 is waiting for requests to
finish that themselves need attention from raid1d.
So we create a new function 'flush_pending_writes' to give that attention, and
call it in freeze_array to be sure that we aren't waiting on raid1d.
Thanks to "K.Tanaka" <k-tanaka@ce.jp.nec.com> for finding and reporting this
problem.
Cc: "K.Tanaka" <k-tanaka@ce.jp.nec.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes two NULL dereferences introduced by commit
06386bbfd2 and spotted by the Coverity
checker.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
d_path() is used on a <dentry,vfsmount> pair. Lets use a struct path to
reflect this.
[akpm@linux-foundation.org: fix build in mm/memory.c]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Bryan Wu <bryan.wu@analog.com>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
seq_path() is always called with a dentry and a vfsmount from a struct path.
Make seq_path() take it directly as an argument.
Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add path_put() functions for releasing a reference to the dentry and
vfsmount of a struct path in the right order
* Switch from path_release(nd) to path_put(&nd->path)
* Rename dput_path() to path_put_conditional()
[akpm@linux-foundation.org: fix cifs]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.
Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
<dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
struct path in every place where the stack can be traversed
- it reduces the overall code size:
without patch series:
text data bss dec hex filename
5321639 858418 715768 6895825 6938d1 vmlinux
with patch series:
text data bss dec hex filename
5320026 858418 715768 6894212 693284 vmlinux
This patch:
Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
test_and_set_bit() on address of uint32_t is a Bad Idea(tm)...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds extra information to the mirror status output, so that
it can be determined which device(s) have failed. For each mirror device,
a character is printed indicating the most severe error encountered. The
characters are:
* A => Alive - No failures
* D => Dead - A write failure occurred leaving mirror out-of-sync
* S => Sync - A sychronization failure occurred, mirror out-of-sync
* R => Read - A read failure occurred, mirror data unaffected
This allows userspace to properly reconfigure the mirror set.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch gives the ability to respond-to/record device failures
that happen during read operations. It also adds the ability to
read from mirror devices that are not the primary if they are
in-sync.
There are essentially two read paths in mirroring; the direct path
and the queued path. When a read request is mapped, if the region
is 'in-sync' the direct path is taken; otherwise the queued path
is taken.
If the direct path is taken, we must record bio information so that
if the read fails we can retry it. We then discover the status of
a direct read through mirror_end_io. If the read has failed, we will
mark the device from which the read was attempted as failed (so we
don't try to read from it again), restore the bio and try again.
If the queued path is taken, we discover the results of the read
from 'read_callback'. If the device failed, we will mark the device
as failed and attempt the read again if there is another device
where this region is known to be 'in-sync'.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch adds the ability to requeue write I/O to
core device-mapper when there is a log device failure.
If a write to the log produces and error, the pending writes are
put on the "failures" list. Since the log is marked as failed,
they will stay on the failures list until a suspend happens.
Suspends come in two phases, presuspend and postsuspend. We must
make sure that all the writes on the failures list are requeued
in the presuspend phase (a requirement of dm core). This means
that recovery must be complete (because writes may be delayed
behind it) and the failures list must be requeued before we
return from presuspend.
The mechanisms to ensure recovery is complete (or stopped) was
already in place, but needed to be moved from postsuspend to
presuspend. We rely on 'flush_workqueue' to ensure that the
mirror thread is complete and therefore, has requeued all writes
in the failures list.
Because we are using flush_workqueue, we must ensure that no
additional 'queue_work' calls will produce additional I/O
that we need to requeue (because once we return from
presuspend, we are unable to do anything about it). 'queue_work'
is called in response to the following functions:
- complete_resync_work = NA, recovery is stopped
- rh_dec (mirror_end_io) = NA, only calls 'queue_work' if it
is ready to recover the region
(recovery is stopped) or it needs
to clear the region in the log*
**this doesn't get called while
suspending**
- rh_recovery_end = NA, recovery is stopped
- rh_recovery_start = NA, recovery is stopped
- write_callback = 1) Writes w/o failures simply call
bio_endio -> mirror_end_io -> rh_dec
(see rh_dec above)
2) Writes with failures are put on
the failures list and queue_work is
called**
** write_callbacks don't happen
during suspend **
- do_failures = NA, 'queue_work' not called if suspending
- add_mirror (initialization) = NA, only done on mirror creation
- queue_bio = NA, 1) delayed I/O scheduled before flush_workqueue
is called. 2) No more I/Os are being issued.
3) Re-attempted READs can still be handled.
(Write completions are handled through rh_dec/
write_callback - mention above - and do not
use queue_bio.)
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch adds the calls to 'fail_mirror' if an error occurs during
mirror recovery (aka resynchronization). 'fail_mirror' is responsible
for recording the type of error by mirror device and ensuring an event
gets raised for the purpose of notifying userspace.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch gives mirror the ability to handle device failures
during normal write operations.
The 'write_callback' function is called when a write completes.
If all the writes failed or succeeded, we report failure or
success respectively. If some of the writes failed, we call
fail_mirror; which increments the error count for the device, notes
the type of error encountered (DM_RAID1_WRITE_ERROR), and
selects a new primary (if necessary). Note that the primary
device can never change while the mirror is not in-sync (IOW,
while recovery is happening.) This means that the scenario
where a failed write changes the primary and gives
recovery_complete a chance to misread the primary never happens.
The fact that the primary can change has necessitated the change
to the default_mirror field. We need to protect against reading
garbage while the primary changes. We then add the bio to a new
list in the mirror set, 'failures'. For every bio in the 'failures'
list, we call a new function, '__bio_mark_nosync', where we mark
the region 'not-in-sync' in the log and properly set the region
state as, RH_NOSYNC. Userspace must also be notified of the
failure. This is done by 'raising an event' (dm_table_event()).
If fail_mirror is called in process context the event can be raised
right away. If in interrupt context, the event is deferred to the
kmirrord thread - which raises the event if 'event_waiting' is set.
Backwards compatibility is maintained by ignoring errors if
the DM_FEATURES_HANDLE_ERRORS flag is not present.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Provided sector_t is 64 bits, reduce the in-memory footprint of the
snapshot exception table by the simple method of using unused bits of
the chunk number to combine consecutive entries.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch adds additional information to the status line. It is added at the
end of the returned text so it will not interfere with existing
implementations using this data. The addition of this information will allow
for a common return interface to match that returned with the dm-raid1.c
status line (with Jonathan Brassow's patches).
Here is a sample of what is returned with a mirror "status" call:
isw_eeaaabgfg_mirror: 0 488390920 mirror 2 8:16 8:32 3727/3727 1 AA 1 core
Here's what's returned with this patch for a stripe "status" call:
isw_dheeijjdej_stripe: 0 976783872 striped 2 8:16 8:32 1 AA
Signed-off-by: Brian Wood <brian.j.wood@intel.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch adds the stripe_end_io function to process errors that might
occur after an IO operation. As part of this there are a number of
enhancements made to record and trigger events:
- New atomic variable in struct stripe to record the number of
errors each stripe volume device has experienced (could be used
later with uevents to report back directly to userspace)
- New workqueue/work struct setup to process the trigger_event function
- New end_io function. It is here that testing for BIO error conditions
take place. It determines the exact stripe that cause the error,
records this in the new atomic variable, and calls the queue_work() function
- New trigger_event function to process failure events. This
calls dm_table_event()
Signed-off-by: Brian Wood <brian.j.wood@intel.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
If the log type is not recognised, attempt to load the module
'dm-log-<type>.ko'.
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add a single-thread workqueue for each mapped device
and move flushing of the lists of pushback and deferred bios
to this new workqueue.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
dm-crypt: Use crypto ablkcipher interface
Move encrypt/decrypt core to async crypto call.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
dm-crypt: Use crypto ablkcipher interface
Prepare callback function for async crypto operation.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
dm-crypt: Use crypto ablkcipher interface
Prepare completion for async crypto request.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
dm-crypt: Use crypto ablkcipher interface
Introduce mempool for async crypto requests.
cc->req is used mainly during synchronous operations
(to prevent allocation and deallocation of the same object).
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
dm-crypt: Use crypto ablkcipher interface
Move scatterlists to separate dm_crypt_struct and
pick out block processing from crypt_convert.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Process write request in separate function and queue
final bio through io workqueue.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Add sector into dm_crypt_io instead of using local variable.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Move error code setting outside of crypt_dec_pending function.
Use -EIO if crypt_convert_scatterlist() fails.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Remove write attribute from convert_context and use bio flag instead.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Drop the EXPERIMENTAL tag from well-established device-mapper targets, so
the newer ones stand out better.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Change io_locking to allow processing flush in separate thread.
Because we have DMF_BLOCK_IO already set, any possible
new ios are queued in dm_requests now.
In the case of interrupting previous wait there can be more
ios queued (we unlocked io_lock for a while) but this is safe.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Tidy dm_suspend function
- change return value logic in dm_suspend
- use atomic_read only once.
- move DMF_BLOCK_IO clearing into one place
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Refactor deferred bio_list processing.
- use separate _merge_pushback_list function
- move deferred bio list pick up to flush function
- use bio_list_pop instead of bio_list_get
- simplify noflush flag use
No real functional change in this patch.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Tidy labels in alloc_dev to make later patches more clear.
No functional change in this patch.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
drivers/md/dm-ioctl.c:1405: warning: 'param' may be used uninitialized in this function
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
drivers/md/dm-table.c: In function 'dm_get_device':
drivers/md/dm-table.c:478: warning: 'dev' may be used uninitialized in this function
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
drivers/md/dm-exception-store.c: In function 'persistent_read_metadata':
drivers/md/dm-exception-store.c:452: warning: 'new_snapshot' may be used uninitialized in this function
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Since the source file already includes the log2.h header file, it
seems pointless to re-invent the necessary routine.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This patch is some minor janitorish cleanup, using some macros
from linux/list.h (already #included via dm.h) to improve
readability.
Signed-off-by: Paul Jimenez <pj@place.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Remove lock_kernel() from the device-mapper ioctls - there should
be sufficient internal locking already where required.
Also remove some superfluous casts.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
raid5's 'make_request' function calls generic_make_request on underlying
devices and if we run out of stripe heads, it could end up waiting for one of
those requests to complete. This is bad as recursive calls to
generic_make_request go on a queue and are not even attempted until
make_request completes.
So: don't make any generic_make_request calls in raid5 make_request until all
waiting has been done. We do this by simply setting STRIPE_HANDLE instead of
calling handle_stripe().
If we need more stripe_heads, raid5d will get called to process the pending
stripe_heads which will call generic_make_request from a
This change by itself causes a performance hit. So add a change so that
raid5_activate_delayed is only called at unplug time, never in raid5. This
seems to bring back the performance numbers. Calling it in raid5d was
sometimes too soon...
Neil said:
How about we queue it for 2.6.25-rc1 and then about when -rc2 comes out,
we queue it for 2.6.24.y?
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Tested-by: dean gaudet <dean@arctic.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Finish ITERATE_ to for_each conversion.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As this is more in line with common practice in the kernel. Also swap the
args around to be more like list_for_each.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As this is more consistent with kernel style.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As suggested by Andrew Morton.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Due to possible deadlock issues we need to use a schedule work to kobject_del
an 'rdev' object from a different thread.
A recent change means that kobject_add no longer gets a refernce, and
kobject_del doesn't put a reference. Consequently, we need to explicitly hold
a reference to ensure that the last reference isn't dropped before the
scheduled work get a chance to call kobject_del.
Also, rename delayed_delete to md_delayed_delete to that it is more obvious in
a stack trace which code is to blame.
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, a given device is "claimed" by a particular array so that it cannot
be used by other arrays.
This is not ideal for DDF and other metadata schemes which have their own
partitioning concept.
So for externally managed metadata, just claim the device for md in general,
require that "offset" and "size" are set properly for each device, and make
sure that if a device is included in different arrays then the active sections
do not overlap.
This involves adding another flag to the rdev which makes it awkward to set
"->flags = 0" to clear certain flags. So now clear flags explicitly by name
when we want to clear things.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If you try to start an array for which the number of raid disks is listed as
zero, md will currently try to read metadata off any devices that have been
given. This was done because the value of raid_disks is used to signal
whether array details have been provided by userspace (raid_disks > 0) or must
be read from the devices (raid_disks == 0).
However for an array without persistent metadata (or with externally managed
metadata) this is the wrong thing to do. So we add a test in do_md_run to
give an error if raid_disks is zero for non-persistent arrays.
This requires that mddev->persistent is set corrently at this point, which it
currently isn't for in-kernel autodetected arrays.
So set ->persistent for autodetect arrays, and remove the settign in
super_*_validate which is now redundant.
Also clear ->persistent when stopping an array so it is consistently zero when
starting an array.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This allows userspace to control resync/reshape progress and synchronise it
with other activities, such as shared access in a SAN, or backing up critical
sections during a tricky reshape.
Writing a number of sectors (which must be a multiple of the chunk size if
such is meaningful) causes a resync to pause when it gets to that point.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a device fails, we must not allow an further writes to the array until
the device failure has been recorded in array metadata. When metadata is
managed externally, this requires some synchronisation...
Allow/require userspace to explicitly remove failed devices from active
service in the array by writing 'none' to the 'slot' attribute. If this
reduces the number of failed devices to 0, the write block will automatically
be lowered.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
