From: Omar Sandoval <osandov@xxxxxx>
Commit 0809e3ac6231 ("block: fix plug list flushing for nomerge queues")
updated blk_mq_make_request() to set request_count even when
blk_queue_nomerges() returns true. However, blk_mq_make_request() only
does limited plugging and doesn't use request_count;
blk_sq_make_request() is the one that should have been fixed. Do that
and get rid of the unnecessary work in the mq version.
Fixes: 0809e3ac6231 ("block: fix plug list flushing for nomerge queues")
Signed-off-by: Omar Sandoval <osandov@xxxxxx>
---
Applies to v4.7-rc1.
block/blk-mq.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 29cbc1b5fbdb..f9b9049b1284 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1262,12 +1262,9 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
blk_queue_split(q, &bio, q->bio_split);
- if (!is_flush_fua && !blk_queue_nomerges(q)) {
- if (blk_attempt_plug_merge(q, bio, &request_count,
- &same_queue_rq))
- return BLK_QC_T_NONE;
- } else
- request_count = blk_plug_queued_count(q);
+ if (!is_flush_fua && !blk_queue_nomerges(q) &&
+ blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
+ return BLK_QC_T_NONE;
rq = blk_mq_map_request(q, bio, &data);
if (unlikely(!rq))
@@ -1358,9 +1355,11 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
blk_queue_split(q, &bio, q->bio_split);
- if (!is_flush_fua && !blk_queue_nomerges(q) &&
- blk_attempt_plug_merge(q, bio, &request_count, NULL))
- return BLK_QC_T_NONE;
+ if (!is_flush_fua && !blk_queue_nomerges(q)) {
+ if (blk_attempt_plug_merge(q, bio, &request_count, NULL))
+ return BLK_QC_T_NONE;
+ } else
+ request_count = blk_plug_queued_count(q);
rq = blk_mq_map_request(q, bio, &data);
if (unlikely(!rq))
--
2.8.3
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