linux/drivers/md
NeilBrown 6d183de407 md/raid5: fix newly-broken locking in get_active_stripe.
commit 566c09c534 raid5: relieve lock contention in get_active_stripe()

modified the locking in get_active_stripe() reducing the range
protected by the (highly contended) device_lock.
Unfortunately it reduced the range too much opening up some races.

One race can occur if get_priority_stripe runs between the
test on sh->count and device_lock being taken.
This will mean that sh->lru is not empty while get_active_stripe
thinks ->count is zero resulting in a 'BUG' firing.

Another race happens if __release_stripe is called immediately
after sh->count is tested and found to be non-zero.  If STRIPE_HANDLE
is not set, get_active_stripe should increment ->active_stripes
when it increments ->count from 0, but as it didn't think it was 0,
it doesn't.

Extending device_lock to cover the test on sh->count close these
races.

While we are here, fix the two BUG tests:
 -If count is zero, then lru really must not be empty, or we've
  lock the stripe_head somehow - no other tests are relevant.
 -STRIPE_ON_RELEASE_LIST is completely independent of ->lru so
  testing it is pointless.

Reported-and-tested-by: Brassow Jonathan <jbrassow@redhat.com>
Reviewed-by: Shaohua Li <shli@kernel.org>
Fixes: 566c09c534
Signed-off-by: NeilBrown <neilb@suse.de>
2013-11-28 11:00:15 +11:00
..
bcache bcache: defensively handle format strings 2013-11-10 21:56:43 -08:00
persistent-data dm space map disk: optimise sm_disk_dec_block 2013-11-09 18:20:24 -05:00
bitmap.c sysfs: clean up sysfs_get_dirent() 2013-09-26 15:33:18 -07:00
bitmap.h md/bitmap: record the space available for the bitmap in the superblock. 2012-05-22 13:55:34 +10:00
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-bufio.c drivers: convert shrinkers to new count/scan API 2013-09-10 18:56:32 -04:00
dm-bufio.h dm bufio: prefetch 2012-03-28 18:41:29 +01:00
dm-cache-block-types.h dm: add cache target 2013-03-01 22:45:51 +00:00
dm-cache-metadata.c dm cache metadata: check the metadata version when reading the superblock 2013-11-11 11:37:49 -05:00
dm-cache-metadata.h dm cache: add passthrough mode 2013-11-11 11:37:49 -05:00
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: resolve small nits and improve Documentation 2013-11-12 13:11:09 -05:00
dm-cache-policy.c dm cache: return -EINVAL if the user specifies unknown cache policy 2013-11-09 18:20:18 -05:00
dm-cache-policy.h dm cache: add remove_cblock method to policy interface 2013-11-11 11:37:50 -05:00
dm-cache-target.c dm cache: resolve small nits and improve Documentation 2013-11-12 13:11:09 -05:00
dm-crypt.c tree-wide: use reinit_completion instead of INIT_COMPLETION 2013-11-15 09:32:21 +09:00
dm-delay.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-exception-store.c dm: replace simple_strtoul 2012-07-27 15:07:59 +01:00
dm-exception-store.h dm snapshot: test chunk size against both origin and snapshot 2010-08-12 04:13:51 +01:00
dm-flakey.c dm flakey: correct ctr alloc failure mesg 2013-07-10 23:41:17 +01:00
dm-io.c dm: add reserved_bio_based_ios module parameter 2013-09-23 10:42:24 -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 dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm-log-userspace-base.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
dm-log-userspace-transfer.c connector/userns: replace netlink uses of cap_raised() with capable() 2012-05-10 23:21:39 -04:00
dm-log-userspace-transfer.h dm log: userspace add luid to distinguish between concurrent log instances 2009-09-04 20:40:34 +01:00
dm-log.c dm: use memweight() 2012-07-30 17:25:16 -07:00
dm-mpath.c dm mpath: requeue I/O during pg_init 2013-11-05 11:20:34 -05:00
dm-mpath.h
dm-path-selector.c md: Add module.h to all files using it implicitly 2011-10-31 19:31:18 -04:00
dm-path-selector.h dm mpath: add start_io and nr_bytes to path selectors 2009-06-22 10:12:27 +01:00
dm-queue-length.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-raid1.c dm: stop using WQ_NON_REENTRANT 2013-08-23 09:02:13 -04:00
dm-raid.c MD: Remember the last sync operation that was performed 2013-06-26 12:38:24 +10:00
dm-region-hash.c dm raid1: fix crash with mirror recovery and discard 2012-07-20 14:25:03 +01:00
dm-round-robin.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-service-time.c dm: reject trailing characters in sccanf input 2012-03-28 18:41:26 +01:00
dm-snap-persistent.c dm snapshot: fix data corruption 2013-10-16 03:17:47 +01:00
dm-snap-transient.c md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
dm-snap.c dm-snapshot: fix performance degradation due to small hash size 2013-09-20 10:36:34 -04:00
dm-stats.c dm stats: fix possible counter corruption on 32-bit systems 2013-09-18 14:41:06 -04:00
dm-stats.h dm: add statistics support 2013-09-05 20:46:06 -04:00
dm-stripe.c dm stripe: silence a couple sparse warnings 2013-09-06 11:36:01 -04:00
dm-switch.c dm: add switch target 2013-07-10 23:41:19 +01:00
dm-sysfs.c Driver core: Constify struct sysfs_ops in struct kobj_type 2010-03-07 17:04:49 -08:00
dm-table.c dm table: print error on preresume failure 2013-11-09 18:20:21 -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: generate event when metadata threshold passed 2013-05-10 14:37:21 +01:00
dm-thin-metadata.h dm thin: generate event when metadata threshold passed 2013-05-10 14:37:21 +01:00
dm-thin.c dm thin: do not expose non-zero discard limits if discards disabled 2013-09-23 10:42:06 -04:00
dm-uevent.c md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
dm-uevent.h
dm-verity.c dm verity: use __ffs and __fls 2013-07-10 23:41:17 +01:00
dm-zero.c dm: rename request variables to bios 2013-03-01 22:45:47 +00:00
dm.c dm: allow remove to be deferred 2013-11-09 18:20:22 -05:00
dm.h dm: allow remove to be deferred 2013-11-09 18:20:22 -05:00
faulty.c block: Add bio_end_sector() 2013-03-23 14:15:29 -07:00
Kconfig dm: fix Kconfig menu indentation 2013-11-09 18:20:22 -05:00
linear.c block: Add bio_end_sector() 2013-03-23 14:15:29 -07:00
linear.h md/linear: typedef removal: linear_conf_t -> struct linear_conf 2011-10-11 16:48:54 +11:00
Makefile dm: add statistics support 2013-09-05 20:46:06 -04:00
md.c md: test mddev->flags more safely in md_check_recovery. 2013-11-28 11:00:08 +11:00
md.h Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block 2013-11-14 12:08:14 +09:00
multipath.c MD: change the parameter of md thread 2012-10-11 13:34:00 +11:00
multipath.h md/multipath: typedef removal: multipath_conf_t -> struct mpconf 2011-10-11 16:48:57 +11:00
raid0.c md: fix buglet in RAID5 -> RAID0 conversion. 2013-06-26 12:38:19 +10:00
raid0.h md: add proper merge_bvec handling to RAID0 and Linear. 2012-03-19 12:46:39 +11:00
raid1.c md update for 3.13. 2013-11-20 13:05:25 -08:00
raid1.h raid1: Rewrite the implementation of iobarrier. 2013-11-19 15:19:18 +11:00
raid5.c md/raid5: fix newly-broken locking in get_active_stripe. 2013-11-28 11:00:15 +11:00
raid5.h md update for 3.13. 2013-11-20 13:05:25 -08:00
raid10.c md update for 3.13. 2013-11-20 13:05:25 -08:00
raid10.h MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1) 2013-02-26 11:55:30 +11:00