Mike Snitzer d132cc6d9e dm cache: prevent corruption caused by discard_block_size > cache_block_size
If the discard block size is larger than the cache block size we will
not properly quiesce IO to a region that is about to be discarded.  This
results in a race between a cache migration where no copy is needed, and
a write to an adjacent cache block that's within the same large discard
block.

Workaround this by limiting the discard_block_size to cache_block_size.
Also limit the max_discard_sectors to cache_block_size.

A more comprehensive fix that introduces range locking support in the
bio_prison and proper quiescing of a discard range that spans multiple
cache blocks is already in development.

Reported-by: Morgan Mears <Morgan.Mears@netapp.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Acked-by: Heinz Mauelshagen <heinzm@redhat.com>
Cc: stable@vger.kernel.org
2014-03-27 16:56:23 -04:00
..
2013-03-01 22:45:51 +00:00
2013-03-01 22:45:51 +00:00
2014-01-14 23:23:03 -05:00
2013-03-01 22:45:51 +00:00
2014-03-27 16:56:23 -04:00
2013-11-23 22:33:47 -08:00
2013-11-09 18:20:22 -05:00
2013-08-23 09:02:13 -04:00
2013-11-23 22:33:47 -08:00
2012-07-30 17:25:16 -07:00
2013-09-05 20:46:06 -04:00
2013-11-23 22:33:47 -08:00
2013-11-23 22:33:47 -08:00
2014-01-14 23:23:04 -05:00
2013-11-23 22:33:56 -08:00
2013-03-01 22:45:47 +00:00
2014-01-14 23:23:04 -05:00
2013-11-23 22:33:47 -08:00
2014-03-27 16:56:23 -04:00
2013-11-23 22:33:57 -08:00
2014-03-27 16:56:23 -04:00
2014-01-20 15:49:44 -08:00
2013-11-23 22:33:47 -08:00
2013-11-23 22:33:57 -08:00
2013-11-20 13:05:25 -08:00