Commit 0809e3ac authored by Jeff Moyer's avatar Jeff Moyer Committed by Jens Axboe
Browse files

block: fix plug list flushing for nomerge queues 



Request queues with merging disabled will not flush the plug list after
BLK_MAX_REQUEST_COUNT requests have been queued, since the code relies
on blk_attempt_plug_merge to compute the request_count.  Fix this by
computing the number of queued requests even for nomerge queues.

Signed-off-by: default avatarJeff Moyer <jmoyer@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 3380f458

block/blk-core.c

+29 −3
Original line number Diff line number Diff line
@@ -1594,6 +1594,30 @@ out: 
	return ret;

}



unsigned int blk_plug_queued_count(struct request_queue *q)

{

	struct blk_plug *plug;

	struct request *rq;

	struct list_head *plug_list;

	unsigned int ret = 0;



	plug = current->plug;

	if (!plug)

		goto out;



	if (q->mq_ops)

		plug_list = &plug->mq_list;

	else

		plug_list = &plug->list;



	list_for_each_entry(rq, plug_list, queuelist) {

		if (rq->q == q)

			ret++;

	}

out:

	return ret;

}



void init_request_from_bio(struct request *req, struct bio *bio)

{

	req->cmd_type = REQ_TYPE_FS;
@@ -1641,9 +1665,11 @@ static void blk_queue_bio(struct request_queue *q, struct bio *bio) 
	 * Check if we can merge with the plugged list before grabbing

	 * any locks.

	 */

	if (!blk_queue_nomerges(q) &&

	    blk_attempt_plug_merge(q, bio, &request_count, NULL))

	if (!blk_queue_nomerges(q)) {

		if (blk_attempt_plug_merge(q, bio, &request_count, NULL))

			return;

	} else

		request_count = blk_plug_queued_count(q);



	spin_lock_irq(q->queue_lock);

block/blk-mq.c

+6 −3
Original line number Diff line number Diff line
@@ -1268,9 +1268,12 @@ static void 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) &&

	    blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))

	if (!is_flush_fua && !blk_queue_nomerges(q)) {

		if (blk_attempt_plug_merge(q, bio, &request_count,

					   &same_queue_rq))

			return;

	} else

		request_count = blk_plug_queued_count(q);



	rq = blk_mq_map_request(q, bio, &data);

	if (unlikely(!rq))

block/blk.h

+1 −0
Original line number Diff line number Diff line
@@ -86,6 +86,7 @@ bool bio_attempt_back_merge(struct request_queue *q, struct request *req, 
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,

			    unsigned int *request_count,

			    struct request **same_queue_rq);

unsigned int blk_plug_queued_count(struct request_queue *q);



void blk_account_io_start(struct request *req, bool new_io);

void blk_account_io_completion(struct request *req, unsigned int bytes);

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