diff options
| author | Mike Snitzer <snitzer@redhat.com> | 2014-03-20 10:11:15 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-13 13:32:55 +0200 |
| commit | 8e0bb904dfd1e98743b8b62301b5d903405cb123 (patch) | |
| tree | 4ca0510308c75c10e07704f39436e665cd9d3072 /net/lapb/lapb_subr.c | |
| parent | e07b5528f1f4adf101968d8c730201fe38b9b514 (diff) | |
dm cache: prevent corruption caused by discard_block_size > cache_block_size
commit d132cc6d9e92424bb9d4fd35f5bd0e55d583f4be upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/lapb/lapb_subr.c')
0 files changed, 0 insertions, 0 deletions