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authorJoe Thornber <ejt@redhat.com>2014-11-27 12:21:08 +0000
committerMike Snitzer <snitzer@redhat.com>2014-12-01 11:30:12 -0500
commitf29a3147e251d7ae20d3194ff67f109d71e501b4 (patch)
tree21867997b4b5be3b677e0265adbfd33d3a6ef4ad /drivers/md
parent2bb812df63bbd246bd39d10f2e810b2a0a59e99e (diff)
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
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-cache-target.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index fd7f61387283..ef842feda101 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -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;
}

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