33 lines
1.0 KiB
Diff
33 lines
1.0 KiB
Diff
From: Joe Thornber <ejt@redhat.com>
|
|
Date: Thu, 27 Nov 2014 12:21:08 +0000
|
|
Subject: [PATCH] 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
|
|
---
|
|
drivers/md/dm-cache-target.c | 3 ++-
|
|
1 file changed, 2 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
|
|
index 7130505c2425..6f7086355691 100644
|
|
--- a/drivers/md/dm-cache-target.c
|
|
+++ b/drivers/md/dm-cache-target.c
|
|
@@ -1070,7 +1070,8 @@ static void issue_copy(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;
|
|
}
|
|
--
|
|
2.1.0
|
|
|