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
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delay.txt
dm-crypt.txt	dm crypt: optionally support discard requests	2011-08-02 12:32:08 +01:00
dm-flakey.txt	dm flakey: add corrupt_bio_byte feature	2011-08-02 12:32:06 +01:00
dm-io.txt
dm-log.txt	dm log userspace: fix comment hyphens	2011-10-31 20:21:22 +00:00
dm-queue-length.txt	dm mpath: add queue length load balancer	2009-06-22 10:12:27 +01:00
dm-raid.txt	DM-RAID: Fix RAID10's check for sufficient redundancy	2013-01-24 12:02:36 +11:00
dm-service-time.txt	Fix common misspellings	2011-03-31 11:26:23 -03:00
dm-uevent.txt
kcopyd.txt
linear.txt
persistent-data.txt	Documentation: Fix multiple typo in Documentation	2012-03-07 16:08:24 +01:00
snapshot.txt	dm: document when snapshot has finished merging	2010-03-06 02:29:56 +00:00
striped.txt	dm stripe: support for non power of 2 chunksize	2012-07-27 15:08:01 +01:00
thin-provisioning.txt	dm thin: add read only and fail io modes	2012-07-27 15:08:16 +01:00
verity.txt	dm: verity fix documentation	2012-07-03 12:55:41 +01:00
zero.txt