diff options
| author | Shaohua Li <shli@fb.com> | 2016-04-25 16:52:38 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-11 11:21:13 +0200 |
| commit | f3b51a03bea6dc4cda740481d48b2ff49abdced5 (patch) | |
| tree | 189450adc4e7e63489209f9ae12ea56b119da19f | |
| parent | 8d2923930be15a5b295ace2029c76653dc4def13 (diff) | |
MD: make bio mergeable
commit 9c573de3283af007ea11c17bde1e4568d9417328 upstream.
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: 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/md/md.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index b1e1f6b95782..c57fdf847b47 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -293,6 +293,8 @@ static blk_qc_t 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(); |