linux/drivers/md
Joe Thornber a9d45396f5 dm transaction manager: fix corruption due to non-atomic transaction commit
The persistent-data library used by dm-thin, dm-cache, etc is
transactional.  If anything goes wrong, such as an io error when writing
new metadata or a power failure, then we roll back to the last
transaction.

Atomicity when committing a transaction is achieved by:

a) Never overwriting data from the previous transaction.
b) Writing the superblock last, after all other metadata has hit the
   disk.

This commit and the following commit ("dm: take care to copy the space
map roots before locking the superblock") fix a bug associated with (b).
When committing it was possible for the superblock to still be written
in spite of an io error occurring during the preceeding metadata flush.
With these commits we're careful not to take the write lock out on the
superblock until after the metadata flush has completed.

Change the transaction manager's semantics for dm_tm_commit() to assume
all data has been flushed _before_ the single superblock that is passed
in.

As a prerequisite, split the block manager's block unlocking and
flushing by simplifying dm_bm_flush_and_unlock() to dm_bm_flush().  Now
the unlocking must be done separately.

This issue was discovered by forcing io errors at the crucial time
using dm-flakey.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
2014-03-27 16:56:23 -04:00
..
bcache Merge branch 'bcache-for-3.14' of git://evilpiepirate.org/~kent/linux-bcache into for-linus 2014-01-30 12:57:55 -07:00
persistent-data dm transaction manager: fix corruption due to non-atomic transaction commit 2014-03-27 16:56:23 -04:00
bitmap.c kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordingly 2013-12-11 15:28:36 -08:00
bitmap.h kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordingly 2013-12-11 15:28:36 -08:00
dm-bio-prison.c dm: add cache target 2013-03-01 22:45:51 +00:00
dm-bio-prison.h dm: add cache target 2013-03-01 22:45:51 +00:00
dm-bio-record.h dm: Refactor for new bio cloning/splitting 2013-11-23 22:33:55 -08:00
dm-bufio.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
dm-bufio.h dm snapshot: use dm-bufio prefetch 2014-01-14 23:23:03 -05:00
dm-builtin.c dm sysfs: fix a module unload race 2014-01-14 23:23:04 -05:00
dm-cache-block-types.h dm cache: remove remainder of distinct discard block size 2014-03-27 16:56:23 -04:00
dm-cache-metadata.c dm transaction manager: fix corruption due to non-atomic transaction commit 2014-03-27 16:56:23 -04:00
dm-cache-metadata.h dm cache: remove remainder of distinct discard block size 2014-03-27 16:56:23 -04:00
dm-cache-policy-cleaner.c dm cache: policy change version from string to integer set 2013-03-20 17:21:27 +00:00
dm-cache-policy-internal.h dm cache: add remove_cblock method to policy interface 2013-11-11 11:37:50 -05:00
dm-cache-policy-mq.c dm cache mq: fix memory allocation failure for large cache devices 2014-02-28 12:18:29 -05:00
dm-cache-policy.c dm cache: add policy name to status output 2014-01-16 13:44:11 -05:00
dm-cache-policy.h dm cache: add policy name to status output 2014-01-16 13:44:11 -05:00
dm-cache-target.c dm cache: remove remainder of distinct discard block size 2014-03-27 16:56:23 -04:00
dm-crypt.c block: Convert drivers to immutable biovecs 2013-11-23 22:33:51 -08:00
dm-delay.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
dm-era-target.c dm: add era target 2014-03-27 16:56:23 -04:00
dm-exception-store.c dm: replace simple_strtoul 2012-07-27 15:07:59 +01:00
dm-exception-store.h
dm-flakey.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-io.c dm io: fix I/O to multiple destinations 2014-02-17 11:00:05 -05:00
dm-ioctl.c dm: allow remove to be deferred 2013-11-09 18:20:22 -05:00
dm-kcopyd.c dm: stop using WQ_NON_REENTRANT 2013-08-23 09:02:13 -04:00
dm-linear.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-log-userspace-base.c dm log userspace: allow mark requests to piggyback on flush requests 2014-01-21 23:46:27 -05:00
dm-log-userspace-transfer.c
dm-log-userspace-transfer.h
dm-log.c dm: use memweight() 2012-07-30 17:25:16 -07:00
dm-mpath.c dm mpath: fix stalls when handling invalid ioctls 2014-02-26 09:44:44 -05:00
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-queue-length.c
dm-raid1.c dm raid1: fix immutable biovec related BUG when retrying read bio 2014-02-18 10:48:57 -05:00
dm-raid.c MD: Remember the last sync operation that was performed 2013-06-26 12:38:24 +10:00
dm-region-hash.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-round-robin.c
dm-service-time.c
dm-snap-persistent.c dm snapshot: fix metadata corruption 2014-03-03 17:58:13 -05:00
dm-snap-transient.c
dm-snap.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
dm-stats.c dm stats: initialize read-only module parameter 2013-12-10 19:13:21 -05:00
dm-stats.h dm: add statistics support 2013-09-05 20:46:06 -04:00
dm-stripe.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-switch.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
dm-sysfs.c dm sysfs: fix a module unload race 2014-01-14 23:23:04 -05:00
dm-table.c dm table: remove unused buggy code that extends the targets array 2014-01-07 10:11:44 -05:00
dm-target.c dm: allow error target to replace bio-based and request-based targets 2013-09-05 20:46:05 -04:00
dm-thin-metadata.c dm thin: ensure user takes action to validate data and metadata consistency 2014-03-05 15:25:35 -05:00
dm-thin-metadata.h dm thin: ensure user takes action to validate data and metadata consistency 2014-03-05 15:25:35 -05:00
dm-thin.c dm thin: fix noflush suspend IO queueing 2014-03-05 15:26:59 -05:00
dm-uevent.c
dm-uevent.h
dm-verity.c block: Generic bio chaining 2013-11-23 22:33:56 -08:00
dm-zero.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
dm.h dm sysfs: fix a module unload race 2014-01-14 23:23:04 -05:00
faulty.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
Kconfig dm: add era target 2014-03-27 16:56:23 -04:00
linear.c block: Introduce new bio_split() 2013-11-23 22:33:57 -08:00
linear.h
Makefile dm: add era target 2014-03-27 16:56:23 -04:00
md.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
md.h Driver core / sysfs patches for 3.14-rc1 2014-01-20 15:49:44 -08:00
multipath.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
multipath.h
raid0.c block: Introduce new bio_split() 2013-11-23 22:33:57 -08:00
raid0.h
raid1.c md/raid1: restore ability for check and repair to fix read errors. 2014-02-05 12:26:04 +11:00
raid1.h raid1: Rewrite the implementation of iobarrier. 2013-11-19 15:19:18 +11:00
raid5.c md/raid5: Fix CPU hotplug callback registration 2014-02-13 13:46:45 +11:00
raid5.h md update for 3.13. 2013-11-20 13:05:25 -08:00
raid10.c Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
raid10.h MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1) 2013-02-26 11:55:30 +11:00