blk-mq: really fix plug list flushing for nomerge queues (87c279e6) · Commits · 戴 / test

Commit ("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: ("block: fix plug list flushing for nomerge queues") Signed-off-by:

Omar Sandoval <osandov@fb.com> Reviewed-by:

Ming Lei <tom.leiming@gmail.com> Reviewed-by:

Jeff Moyer <jmoyer@redhat.com> Signed-off-by:

Jens Axboe <axboe@fb.com>

block/blk-mq.c

+8 −9

Original line number	Diff line number	Diff line
		@@ -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))
		if (!is_flush_fua && !blk_queue_nomerges(q) &&
		blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
		return BLK_QC_T_NONE;
		} else
		request_count = blk_plug_queued_count(q);

		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))
		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))

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