linux/drivers/md
Jonathan Brassow 55ebbb59c1 DM-RAID: Fix RAID10's check for sufficient redundancy
Before attempting to activate a RAID array, it is checked for sufficient
redundancy.  That is, we make sure that there are not too many failed
devices - or devices specified for rebuild - to undermine our ability to
activate the array.  The current code performs this check twice - once to
ensure there were not too many devices specified for rebuild by the user
('validate_rebuild_devices') and again after possibly experiencing a failure
to read the superblock ('analyse_superblocks').  Neither of these checks are
sufficient.  The first check is done properly but with insufficient
information about the possible failure state of the devices to make a good
determination if the array can be activated.  The second check is simply
done wrong in the case of RAID10 because it doesn't account for the
independence of the stripes (i.e. mirror sets).  The solution is to use the
properly written check ('validate_rebuild_devices'), but perform the check
after the superblocks have been read and we know which devices have failed.
This gives us one check instead of two and performs it in a location where
it can be done right.

Only RAID10 was affected and it was affected in the following ways:
- the code did not properly catch the condition where a user specified
  a device for rebuild that already had a failed device in the same mirror
  set.  (This condition would, however, be caught at a deeper level in MD.)
- the code triggers a false positive and denies activation when devices in
  independent mirror sets have failed - counting the failures as though they
  were all in the same set.

The most likely place this error was introduced (or this patch should have
been included) is in commit 4ec1e369 - first introduced in v3.7-rc1.
Consequently this fix should also go in v3.7.y, however there is a
small conflict on the .version in raid_target, so I'll submit a
separate patch to -stable.

Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2013-01-24 12:02:36 +11:00
..
persistent-data Miscellaneous device-mapper fixes, cleanups and performance improvements. 2012-12-21 17:08:06 -08:00
Kconfig dm thin: move bio_prison code to separate module 2012-10-12 21:02:13 +01:00
Makefile dm thin: move bio_prison code to separate module 2012-10-12 21:02:13 +01:00
bitmap.c md/bitmap:Don't use IS_ERR to judge alloc_page(). 2012-10-11 13:45:36 +11:00
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 thin: replace dm_cell_release_singleton with cell_defer_except 2012-12-21 20:23:31 +00:00
dm-bio-prison.h dm thin: replace dm_cell_release_singleton with cell_defer_except 2012-12-21 20:23:31 +00:00
dm-bio-record.h dm: preserve bi_io_vec when resubmitting bios 2009-04-02 19:55:23 +01:00
dm-bufio.c dm: use ACCESS_ONCE for sysfs values 2012-10-12 16:59:46 +01:00
dm-bufio.h dm bufio: prefetch 2012-03-28 18:41:29 +01:00
dm-crypt.c dm: remove map_info 2012-12-21 20:23:41 +00:00
dm-delay.c dm: remove map_info 2012-12-21 20:23:41 +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: remove map_info 2012-12-21 20:23:41 +00:00
dm-io.c dm kcopyd: add WRITE SAME support to dm_kcopyd_zero 2012-12-21 20:23:37 +00:00
dm-ioctl.c dm ioctl: use kmalloc if possible 2012-12-21 20:23:36 +00:00
dm-kcopyd.c dm kcopyd: add WRITE SAME support to dm_kcopyd_zero 2012-12-21 20:23:37 +00:00
dm-linear.c dm: remove map_info 2012-12-21 20:23:41 +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: fix check for null mpio in end_io fn 2012-10-12 16:59:42 +01:00
dm-mpath.h dm mpath: remove is_active from struct dm_path 2008-10-10 13:36:58 +01:00
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-raid.c DM-RAID: Fix RAID10's check for sufficient redundancy 2013-01-24 12:02:36 +11:00
dm-raid1.c dm: remove map_info 2012-12-21 20:23:41 +00:00
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 md: Add in export.h for files using EXPORT_SYMBOL 2011-10-31 19:31:19 -04:00
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: remove map_info 2012-12-21 20:23:41 +00:00
dm-stripe.c dm stripe: add WRITE SAME support 2012-12-21 20:23:41 +00:00
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: introduce per_bio_data 2012-12-21 20:23:38 +00:00
dm-target.c dm: remove map_info 2012-12-21 20:23:41 +00:00
dm-thin-metadata.c dm persistent data: fix nested btree deletion 2012-12-21 20:23:32 +00:00
dm-thin-metadata.h dm thin metadata: introduce dm_pool_abort_metadata 2012-07-27 15:08:15 +01:00
dm-thin.c dm: remove map_info 2012-12-21 20:23:41 +00:00
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: remove map_info 2012-12-21 20:23:41 +00:00
dm-zero.c dm: remove map_info 2012-12-21 20:23:41 +00:00
dm.c dm: remove map_info 2012-12-21 20:23:41 +00:00
dm.h dm: introduce per_bio_data 2012-12-21 20:23:38 +00:00
faulty.c md faulty: use disk_stack_limits() 2012-10-22 10:44:55 +11:00
linear.c md: linear supports TRIM 2012-10-11 13:08:44 +11:00
linear.h md/linear: typedef removal: linear_conf_t -> struct linear_conf 2011-10-11 16:48:54 +11:00
md.c md update for 3.8 2012-12-18 09:32:44 -08:00
md.h md update for 3.8 2012-12-18 09:32:44 -08:00
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: raid 0 supports TRIM 2012-10-11 13:25:44 +11:00
raid0.h md: add proper merge_bvec handling to RAID0 and Linear. 2012-03-19 12:46:39 +11:00
raid1.c Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-block 2012-12-17 13:39:11 -08:00
raid1.h md/raid1: prevent merging too large request 2012-07-31 10:03:53 +10:00
raid5.c md update for 3.8 2012-12-18 09:32:44 -08:00
raid5.h MD: raid5 trim support 2012-10-11 13:49:05 +11:00
raid10.c Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-block 2012-12-17 13:39:11 -08:00
raid10.h md/raid10: fix problem with on-stack allocation of r10bio structure. 2012-08-18 09:51:42 +10:00