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authorShaohua Li <shli@fb.com>2016-04-25 16:52:38 -0700
committerSasha Levin <sasha.levin@oracle.com>2016-05-17 13:42:41 -0400
commitcdfac06ee2d5aabbe89724c6a4a3fbb1148fcc7a (patch)
tree483fc69eaa37345b292657bf47fa5c1b403b7bab /drivers/md/md.c
parent4f1948989e9af00623bb23d321cae7bd4792002e (diff)
MD: make bio mergeable
[ Upstream commit 9c573de3283af007ea11c17bde1e4568d9417328 ] blk_queue_split marks bio unmergeable, which makes sense for normal bio. But if dispatching the bio to underlayer disk, the blk_queue_split checks are invalid, hence it's possible the bio becomes mergeable. In the reported bug, this bug causes trim against raid0 performance slash https://bugzilla.kernel.org/show_bug.cgi?id=117051 Reported-and-tested-by: Park Ju Hyung <qkrwngud825@gmail.com> Fixes: 6ac45aeb6bca(block: avoid to merge splitted bio) Cc: stable@vger.kernel.org (v4.3+) Cc: Ming Lei <ming.lei@canonical.com> Cc: Neil Brown <neilb@suse.de> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'drivers/md/md.c')
-rw-r--r--drivers/md/md.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 78c1f77e7903..72dc91de80f8 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -289,6 +289,8 @@ static void md_make_request(struct request_queue *q, struct bio *bio)
* go away inside make_request
*/
sectors = bio_sectors(bio);
+ /* bio could be mergeable after passing to underlayer */
+ bio->bi_rw &= ~REQ_NOMERGE;
mddev->pers->make_request(mddev, bio);
cpu = part_stat_lock();