Commit accea322 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: add a bio_queue_enter helper 



Add a little helper that passes the right nowait flag to blk_queue_enter
based on the bio flag, and terminates the bio with the right error code
if entering the queue fails.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0376e9ef

block/blk-core.c

+24 −26
Original line number Diff line number Diff line
@@ -440,6 +440,23 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) 
	}

}



static inline int bio_queue_enter(struct bio *bio)

{

	struct request_queue *q = bio->bi_disk->queue;

	bool nowait = bio->bi_opf & REQ_NOWAIT;

	int ret;



	ret = blk_queue_enter(q, nowait ? BLK_MQ_REQ_NOWAIT : 0);

	if (unlikely(ret)) {

		if (nowait && !blk_queue_dying(q))

			bio_wouldblock_error(bio);

		else

			bio_io_error(bio);

	}



	return ret;

}



void blk_queue_exit(struct request_queue *q)

{

	percpu_ref_put(&q->q_usage_counter);
@@ -1049,10 +1066,8 @@ blk_qc_t generic_make_request(struct bio *bio) 
	current->bio_list = bio_list_on_stack;

	do {

		struct request_queue *q = bio->bi_disk->queue;

		blk_mq_req_flags_t flags = bio->bi_opf & REQ_NOWAIT ?

			BLK_MQ_REQ_NOWAIT : 0;



		if (likely(blk_queue_enter(q, flags) == 0)) {

		if (likely(bio_queue_enter(bio) == 0)) {

			struct bio_list lower, same;



			/* Create a fresh bio_list for all subordinate requests */
@@ -1079,12 +1094,6 @@ blk_qc_t generic_make_request(struct bio *bio) 
			bio_list_merge(&bio_list_on_stack[0], &lower);

			bio_list_merge(&bio_list_on_stack[0], &same);

			bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]);

		} else {

			if (unlikely(!blk_queue_dying(q) &&

					(bio->bi_opf & REQ_NOWAIT)))

				bio_wouldblock_error(bio);

			else

				bio_io_error(bio);

		}

		bio = bio_list_pop(&bio_list_on_stack[0]);

	} while (bio);
@@ -1106,30 +1115,19 @@ EXPORT_SYMBOL(generic_make_request); 
blk_qc_t direct_make_request(struct bio *bio)

{

	struct request_queue *q = bio->bi_disk->queue;

	bool nowait = bio->bi_opf & REQ_NOWAIT;

	blk_qc_t ret;



	if (WARN_ON_ONCE(q->make_request_fn))

		goto io_error;

	if (!generic_make_request_checks(bio))

	if (WARN_ON_ONCE(q->make_request_fn)) {

		bio_io_error(bio);

		return BLK_QC_T_NONE;



	if (unlikely(blk_queue_enter(q, nowait ? BLK_MQ_REQ_NOWAIT : 0))) {

		if (nowait && !blk_queue_dying(q))

			goto would_block;

		goto io_error;

	}



	if (!generic_make_request_checks(bio))

		return BLK_QC_T_NONE;

	if (unlikely(bio_queue_enter(bio)))

		return BLK_QC_T_NONE;

	ret = blk_mq_make_request(q, bio);

	blk_queue_exit(q);

	return ret;



would_block:

	bio_wouldblock_error(bio);

	return BLK_QC_T_NONE;

io_error:

	bio_io_error(bio);

	return BLK_QC_T_NONE;

}

EXPORT_SYMBOL_GPL(direct_make_request);