linux/drivers/md
NeilBrown 9c4bdf697c md/raid6: avoid data corruption during recovery of double-degraded RAID6
During recovery of a double-degraded RAID6 it is possible for
some blocks not to be recovered properly, leading to corruption.

If a write happens to one block in a stripe that would be written to a
missing device, and at the same time that stripe is recovering data
to the other missing device, then that recovered data may not be written.

This patch skips, in the double-degraded case, an optimisation that is
only safe for single-degraded arrays.

Bug was introduced in 2.6.32 and fix is suitable for any kernel since
then.  In an older kernel with separate handle_stripe5() and
handle_stripe6() functions the patch must change handle_stripe6().

Cc: stable@vger.kernel.org (2.6.32+)
Fixes: 6c0069c0ae
Cc: Yuri Tikhonov <yur@emcraft.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Reported-by: "Manibalan P" <pmanibalan@amiindia.co.in>
Tested-by: "Manibalan P" <pmanibalan@amiindia.co.in>
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1090423
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
2014-08-18 14:49:46 +10:00
..
bcache bcache: Drop unneeded blk_sync_queue() calls 2014-08-04 15:23:04 -07:00
persistent-data dm transaction manager: fix corruption due to non-atomic transaction commit 2014-03-27 16:56:23 -04:00
Kconfig dm: add era target 2014-03-27 16:56:23 -04:00
Makefile dm: add era target 2014-03-27 16:56:23 -04:00
bitmap.c md/bitmap: remove confusing code from filemap_get_page. 2014-05-29 16:59:47 +10:00
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 bio prison: implement per bucket locking in the dm_bio_prison hash table 2014-06-11 16:48:54 -04:00
dm-bio-prison.h dm thin: return ENOSPC instead of EIO when error_if_no_space enabled 2014-06-03 13:44:08 -04:00
dm-bio-record.h dm: Refactor for new bio cloning/splitting 2013-11-23 22:33:55 -08:00
dm-bufio.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-08-04 16:23:30 -07:00
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 cache metadata: use dm-space-map-metadata.h defined size limits 2014-08-01 12:30:33 -04:00
dm-cache-metadata.h dm cache metadata: use dm-space-map-metadata.h defined size limits 2014-08-01 12:30:33 -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: set minimum_io_size to cache's data block size 2014-08-01 12:30:36 -04:00
dm-crypt.c dm crypt: use per-bio data 2014-08-01 12:30:35 -04:00
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 era: check for a non-NULL metadata object before closing it 2014-06-03 13:44:08 -04:00
dm-exception-store.c
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: simplify dec_count and sync_io 2014-08-01 12:30:30 -04:00
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 connector: add portid to unicast in addition to broadcasting 2014-02-07 15:40:17 -08:00
dm-log-userspace-transfer.h
dm-log.c
dm-mpath.c dm mpath: eliminate pg_ready() wrapper 2014-08-01 12:30:31 -04:00
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-queue-length.c
dm-raid.c MD: Remember the last sync operation that was performed 2013-06-26 12:38:24 +10:00
dm-raid1.c dm raid1: fix immutable biovec related BUG when retrying read bio 2014-02-18 10:48:57 -05:00
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 sched: Remove proliferation of wait_on_bit() action functions 2014-07-16 15:10:39 +02:00
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 dm switch: efficiently support repetitive patterns 2014-08-01 12:30:37 -04:00
dm-sysfs.c dm sysfs: fix a module unload race 2014-01-14 23:23:04 -05:00
dm-table.c dm table: propagate QUEUE_FLAG_NO_SG_MERGE 2014-08-10 20:54:49 -04:00
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 metadata: do not allow the data block size to change 2014-07-15 14:05:26 -04:00
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: set minimum_io_size to pool's data block size 2014-08-01 12:30:35 -04:00
dm-uevent.c
dm-uevent.h
dm-verity.c dm verity: fix biovecs hash calculation regression 2014-04-15 12:19:24 -04:00
dm-zero.c dm crypt, dm zero: update author name following legal name change 2014-07-10 16:44:14 -04:00
dm.c dm: allocate a special workqueue for deferred device removal 2014-07-10 16:44:13 -04:00
dm.h dm table: make dm_table_supports_discards static 2014-08-01 12:30:34 -04:00
faulty.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
linear.c block: Introduce new bio_split() 2013-11-23 22:33:57 -08:00
linear.h
md.c md: don't allow bitmap file to be added to raid0/linear. 2014-08-08 15:43:20 +10:00
md.h md/bitmap: don't abuse i_writecount for bitmap files. 2014-04-09 12:26:59 +10:00
multipath.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
multipath.h
raid0.c md/raid0: check for bitmap compatability when changing raid levels. 2014-08-08 15:33:17 +10:00
raid0.h
raid1.c md/raid1,raid10: always abort recover on write error. 2014-07-31 10:16:52 +10:00
raid1.h raid1: Rewrite the implementation of iobarrier. 2013-11-19 15:19:18 +11:00
raid5.c md/raid6: avoid data corruption during recovery of double-degraded RAID6 2014-08-18 14:49:46 +10:00
raid5.h raid5: add an option to avoid copy data from bio to stripe cache 2014-05-29 16:59:47 +10:00
raid10.c md/raid1,raid10: always abort recover on write error. 2014-07-31 10:16:52 +10:00
raid10.h MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1) 2013-02-26 11:55:30 +11:00