Commit f29a3147 authored Nov 27, 2014 by Joe Thornber Committed by Mike Snitzer Dec 01, 2014

dm cache: only use overwrite optimisation for promotion when in writeback mode



Overwrite causes the cache block and origin blocks to diverge, which
is only allowed in writeback mode.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org

parent 2bb812df

drivers/md/dm-cache-target.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1142,7 +1142,8 @@ static void issue_copy_or_discard(struct dm_cache_migration *mg)

		avoid = is_discarded_oblock(cache, mg->new_oblock);

		if (!avoid && bio_writes_complete_block(cache, bio)) {
		if (writeback_mode(&cache->features) &&
		!avoid && bio_writes_complete_block(cache, bio)) {
		issue_overwrite(mg, bio);
		return;
		}