diff options
| author | Jan Kara <jack@suse.cz> | 2017-05-31 09:44:32 +0200 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2017-05-31 10:50:23 -0400 |
| commit | ff0361b34ac63ef80c785c32d62e0e9d89a2cf89 (patch) | |
| tree | df6bce75c164f09c052d464bfbf4d2ba7f44797e /drivers/md/dm-snap-persistent.c | |
| parent | 8c1e2162f27b319da913683143c0c6c09b083ebb (diff) | |
dm: make flush bios explicitly sync
Commit b685d3d65ac7 ("block: treat REQ_FUA and REQ_PREFLUSH as
synchronous") removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions. generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions.
Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.
Fixes: b685d3d65ac7 ("block: treat REQ_FUA and REQ_PREFLUSH as synchronous")
Cc: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-snap-persistent.c')
| -rw-r--r-- | drivers/md/dm-snap-persistent.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c index b93476c3ba3f..c5534d294773 100644 --- a/drivers/md/dm-snap-persistent.c +++ b/drivers/md/dm-snap-persistent.c @@ -741,7 +741,8 @@ static void persistent_commit_exception(struct dm_exception_store *store, /* * Commit exceptions to disk. */ - if (ps->valid && area_io(ps, REQ_OP_WRITE, REQ_PREFLUSH | REQ_FUA)) + if (ps->valid && area_io(ps, REQ_OP_WRITE, + REQ_PREFLUSH | REQ_FUA | REQ_SYNC)) ps->valid = 0; /* |