Commit 5eb6126e authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

blk-mq: improve blk_mq_try_issue_directly 



Rename blk_mq_try_issue_directly to __blk_mq_try_issue_directly and add a
new wrapper that takes care of RCU / SRCU locking to avoid having
boileplate code in the caller which would get duplicated with new callers.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarBart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 254d259d

block/blk-mq.c

+18 −14
Original line number Diff line number Diff line
@@ -1430,7 +1430,7 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) 
	return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true);

}



static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie,

static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie,

				      bool may_sleep)

{

	struct request_queue *q = rq->q;
@@ -1475,13 +1475,27 @@ insert: 
	blk_mq_sched_insert_request(rq, false, true, false, may_sleep);

}



static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,

		struct request *rq, blk_qc_t *cookie)

{

	if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {

		rcu_read_lock();

		__blk_mq_try_issue_directly(rq, cookie, false);

		rcu_read_unlock();

	} else {

		unsigned int srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu);

		__blk_mq_try_issue_directly(rq, cookie, true);

		srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx);

	}

}



static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)

{

	const int is_sync = op_is_sync(bio->bi_opf);

	const int is_flush_fua = op_is_flush(bio->bi_opf);

	struct blk_mq_alloc_data data = { .flags = 0 };

	struct request *rq;

	unsigned int request_count = 0, srcu_idx;

	unsigned int request_count = 0;

	struct blk_plug *plug;

	struct request *same_queue_rq = NULL;

	blk_qc_t cookie;
@@ -1579,18 +1593,8 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) 
		} else /* is_sync */

			old_rq = rq;

		blk_mq_put_ctx(data.ctx);

		if (!old_rq)

			goto done;



		if (!(data.hctx->flags & BLK_MQ_F_BLOCKING)) {

			rcu_read_lock();

			blk_mq_try_issue_directly(old_rq, &cookie, false);

			rcu_read_unlock();

		} else {

			srcu_idx = srcu_read_lock(&data.hctx->queue_rq_srcu);

			blk_mq_try_issue_directly(old_rq, &cookie, true);

			srcu_read_unlock(&data.hctx->queue_rq_srcu, srcu_idx);

		}

		if (old_rq)

			blk_mq_try_issue_directly(data.hctx, old_rq, &cookie);

		goto done;

	}

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