Commit e9907009 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: move req_gap_{back,front}_merge to blk-merge.c 



Keep it close to the actual users instead of exposing the function to all
drivers.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 43b729bf

block/blk-merge.c

+65 −0
Original line number Diff line number Diff line
@@ -12,6 +12,71 @@ 


#include "blk.h"



/*

 * Check if the two bvecs from two bios can be merged to one segment.  If yes,

 * no need to check gap between the two bios since the 1st bio and the 1st bvec

 * in the 2nd bio can be handled in one segment.

 */

static inline bool bios_segs_mergeable(struct request_queue *q,

		struct bio *prev, struct bio_vec *prev_last_bv,

		struct bio_vec *next_first_bv)

{

	if (!BIOVEC_PHYS_MERGEABLE(prev_last_bv, next_first_bv))

		return false;

	if (!BIOVEC_SEG_BOUNDARY(q, prev_last_bv, next_first_bv))

		return false;

	if (prev->bi_seg_back_size + next_first_bv->bv_len >

			queue_max_segment_size(q))

		return false;

	return true;

}



static inline bool bio_will_gap(struct request_queue *q,

		struct request *prev_rq, struct bio *prev, struct bio *next)

{

	struct bio_vec pb, nb;



	if (!bio_has_data(prev) || !queue_virt_boundary(q))

		return false;



	/*

	 * Don't merge if the 1st bio starts with non-zero offset, otherwise it

	 * is quite difficult to respect the sg gap limit.  We work hard to

	 * merge a huge number of small single bios in case of mkfs.

	 */

	if (prev_rq)

		bio_get_first_bvec(prev_rq->bio, &pb);

	else

		bio_get_first_bvec(prev, &pb);

	if (pb.bv_offset)

		return true;



	/*

	 * We don't need to worry about the situation that the merged segment

	 * ends in unaligned virt boundary:

	 *

	 * - if 'pb' ends aligned, the merged segment ends aligned

	 * - if 'pb' ends unaligned, the next bio must include

	 *   one single bvec of 'nb', otherwise the 'nb' can't

	 *   merge with 'pb'

	 */

	bio_get_last_bvec(prev, &pb);

	bio_get_first_bvec(next, &nb);

	if (bios_segs_mergeable(q, prev, &pb, &nb))

		return false;

	return __bvec_gap_to_prev(q, &pb, nb.bv_offset);

}



static inline bool req_gap_back_merge(struct request *req, struct bio *bio)

{

	return bio_will_gap(req->q, req, req->biotail, bio);

}



static inline bool req_gap_front_merge(struct request *req, struct bio *bio)

{

	return bio_will_gap(req->q, NULL, bio, req->bio);

}



static struct bio *blk_bio_discard_split(struct request_queue *q,

					 struct bio *bio,

					 struct bio_set *bs,

include/linux/blkdev.h

+0 −69
Original line number Diff line number Diff line
@@ -1695,75 +1695,6 @@ static inline bool bvec_gap_to_prev(struct request_queue *q, 
	return __bvec_gap_to_prev(q, bprv, offset);

}



/*

 * Check if the two bvecs from two bios can be merged to one segment.

 * If yes, no need to check gap between the two bios since the 1st bio

 * and the 1st bvec in the 2nd bio can be handled in one segment.

 */

static inline bool bios_segs_mergeable(struct request_queue *q,

		struct bio *prev, struct bio_vec *prev_last_bv,

		struct bio_vec *next_first_bv)

{

	if (!BIOVEC_PHYS_MERGEABLE(prev_last_bv, next_first_bv))

		return false;

	if (!BIOVEC_SEG_BOUNDARY(q, prev_last_bv, next_first_bv))

		return false;

	if (prev->bi_seg_back_size + next_first_bv->bv_len >

			queue_max_segment_size(q))

		return false;

	return true;

}



static inline bool bio_will_gap(struct request_queue *q,

				struct request *prev_rq,

				struct bio *prev,

				struct bio *next)

{

	if (bio_has_data(prev) && queue_virt_boundary(q)) {

		struct bio_vec pb, nb;



		/*

		 * don't merge if the 1st bio starts with non-zero

		 * offset, otherwise it is quite difficult to respect

		 * sg gap limit. We work hard to merge a huge number of small

		 * single bios in case of mkfs.

		 */

		if (prev_rq)

			bio_get_first_bvec(prev_rq->bio, &pb);

		else

			bio_get_first_bvec(prev, &pb);

		if (pb.bv_offset)

			return true;



		/*

		 * We don't need to worry about the situation that the

		 * merged segment ends in unaligned virt boundary:

		 *

		 * - if 'pb' ends aligned, the merged segment ends aligned

		 * - if 'pb' ends unaligned, the next bio must include

		 *   one single bvec of 'nb', otherwise the 'nb' can't

		 *   merge with 'pb'

		 */

		bio_get_last_bvec(prev, &pb);

		bio_get_first_bvec(next, &nb);



		if (!bios_segs_mergeable(q, prev, &pb, &nb))

			return __bvec_gap_to_prev(q, &pb, nb.bv_offset);

	}



	return false;

}



static inline bool req_gap_back_merge(struct request *req, struct bio *bio)

{

	return bio_will_gap(req->q, req, req->biotail, bio);

}



static inline bool req_gap_front_merge(struct request *req, struct bio *bio)

{

	return bio_will_gap(req->q, NULL, bio, req->bio);

}



int kblockd_schedule_work(struct work_struct *work);

int kblockd_schedule_work_on(int cpu, struct work_struct *work);

int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);