diff options
author | Mike Snitzer <snitzer@redhat.com> | 2014-03-20 10:11:15 -0400 |
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committer | Mike Snitzer <snitzer@redhat.com> | 2014-03-27 16:56:23 -0400 |
commit | d132cc6d9e92424bb9d4fd35f5bd0e55d583f4be (patch) | |
tree | 9e436740996dd835cf2d9fff2c148cc48cf7b9e9 /drivers/md/raid5.h | |
parent | 428e4698642794444cdb26c148a827f22c28d546 (diff) |
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
Diffstat (limited to 'drivers/md/raid5.h')
0 files changed, 0 insertions, 0 deletions