Commit e37b5596 authored by Yu Kuai's avatar Yu Kuai Committed by Jens Axboe
Browse files

block: factor out a helper bio_submit_split_bioset() 



No functional changes are intended, some drivers like mdraid will split
bio by internal processing, prepare to unify bio split codes.

Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 06d712d2

block/blk-merge.c

+40 −19
Original line number Diff line number Diff line
@@ -104,35 +104,56 @@ static unsigned int bio_allowed_max_sectors(const struct queue_limits *lim) 
	return round_down(UINT_MAX, lim->logical_block_size) >> SECTOR_SHIFT;

}



static struct bio *bio_submit_split(struct bio *bio, int split_sectors)

/*

 * bio_submit_split_bioset - Submit a bio, splitting it at a designated sector

 * @bio:		the original bio to be submitted and split

 * @split_sectors:	the sector count at which to split

 * @bs:			the bio set used for allocating the new split bio

 *

 * The original bio is modified to contain the remaining sectors and submitted.

 * The caller is responsible for submitting the returned bio.

 *

 * If succeed, the newly allocated bio representing the initial part will be

 * returned, on failure NULL will be returned and original bio will fail.

 */

struct bio *bio_submit_split_bioset(struct bio *bio, unsigned int split_sectors,

				    struct bio_set *bs)

{

	if (unlikely(split_sectors < 0))

		goto error;

	struct bio *split = bio_split(bio, split_sectors, GFP_NOIO, bs);



	if (split_sectors) {

		struct bio *split;



		split = bio_split(bio, split_sectors, GFP_NOIO,

				&bio->bi_bdev->bd_disk->bio_split);

	if (IS_ERR(split)) {

			split_sectors = PTR_ERR(split);

			goto error;

		bio->bi_status = errno_to_blk_status(PTR_ERR(split));

		bio_endio(bio);

		return NULL;

	}

		split->bi_opf |= REQ_NOMERGE;



	bio_chain(split, bio);

	trace_block_split(split, bio->bi_iter.bi_sector);

	WARN_ON_ONCE(bio_zone_write_plugging(bio));

	submit_bio_noacct(bio);



	return split;

}

EXPORT_SYMBOL_GPL(bio_submit_split_bioset);



	return bio;

error:

static struct bio *bio_submit_split(struct bio *bio, int split_sectors)

{

	if (unlikely(split_sectors < 0)) {

		bio->bi_status = errno_to_blk_status(split_sectors);

		bio_endio(bio);

		return NULL;

	}



	if (split_sectors) {

		bio = bio_submit_split_bioset(bio, split_sectors,

				&bio->bi_bdev->bd_disk->bio_split);

		if (bio)

			bio->bi_opf |= REQ_NOMERGE;

	}



	return bio;

}



struct bio *bio_split_discard(struct bio *bio, const struct queue_limits *lim,

		unsigned *nsegs)

{

include/linux/blkdev.h

+2 −0
Original line number Diff line number Diff line
@@ -1000,6 +1000,8 @@ extern int blk_register_queue(struct gendisk *disk); 
extern void blk_unregister_queue(struct gendisk *disk);

void submit_bio_noacct(struct bio *bio);

struct bio *bio_split_to_limits(struct bio *bio);

struct bio *bio_submit_split_bioset(struct bio *bio, unsigned int split_sectors,

				    struct bio_set *bs);



extern int blk_lld_busy(struct request_queue *q);

extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);