Commit 6869875f authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: remove the bi_seg_{front,back}_size fields in struct bio 



At this point these fields aren't used for anything, so we can remove
them.

Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 200a9aff

block/blk-merge.c

+12 −82
Original line number Diff line number Diff line
@@ -162,8 +162,7 @@ static unsigned get_max_segment_size(struct request_queue *q, 
 * variables.

 */

static bool bvec_split_segs(struct request_queue *q, struct bio_vec *bv,

		unsigned *nsegs, unsigned *last_seg_size,

		unsigned *front_seg_size, unsigned *sectors, unsigned max_segs)

		unsigned *nsegs, unsigned *sectors, unsigned max_segs)

{

	unsigned len = bv->bv_len;

	unsigned total_len = 0;
@@ -185,27 +184,11 @@ static bool bvec_split_segs(struct request_queue *q, struct bio_vec *bv, 
			break;

	}



	if (!new_nsegs)

		return !!len;



	/* update front segment size */

	if (!*nsegs) {

		unsigned first_seg_size;



		if (new_nsegs == 1)

			first_seg_size = get_max_segment_size(q, bv->bv_offset);

		else

			first_seg_size = queue_max_segment_size(q);



		if (*front_seg_size < first_seg_size)

			*front_seg_size = first_seg_size;

	}



	/* update other varibles */

	*last_seg_size = seg_size;

	if (new_nsegs) {

		*nsegs += new_nsegs;

		if (sectors)

			*sectors += total_len >> 9;

	}



	/* split in the middle of the bvec if len != 0 */

	return !!len;
@@ -218,8 +201,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, 
{

	struct bio_vec bv, bvprv, *bvprvp = NULL;

	struct bvec_iter iter;

	unsigned seg_size = 0, nsegs = 0, sectors = 0;

	unsigned front_seg_size = bio->bi_seg_front_size;

	unsigned nsegs = 0, sectors = 0;

	bool do_split = true;

	struct bio *new = NULL;

	const unsigned max_sectors = get_max_io_size(q, bio);
@@ -243,8 +225,6 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, 
				/* split in the middle of bvec */

				bv.bv_len = (max_sectors - sectors) << 9;

				bvec_split_segs(q, &bv, &nsegs,

						&seg_size,

						&front_seg_size,

						&sectors, max_segs);

			}

			goto split;
@@ -258,12 +238,9 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, 


		if (bv.bv_offset + bv.bv_len <= PAGE_SIZE) {

			nsegs++;

			seg_size = bv.bv_len;

			sectors += bv.bv_len >> 9;

			if (nsegs == 1 && seg_size > front_seg_size)

				front_seg_size = seg_size;

		} else if (bvec_split_segs(q, &bv, &nsegs, &seg_size,

				    &front_seg_size, &sectors, max_segs)) {

		} else if (bvec_split_segs(q, &bv, &nsegs, &sectors,

				max_segs)) {

			goto split;

		}

	}
@@ -278,10 +255,6 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, 
			bio = new;

	}



	bio->bi_seg_front_size = front_seg_size;

	if (seg_size > bio->bi_seg_back_size)

		bio->bi_seg_back_size = seg_size;



	return do_split ? new : NULL;

}
@@ -336,17 +309,13 @@ EXPORT_SYMBOL(blk_queue_split); 
static unsigned int __blk_recalc_rq_segments(struct request_queue *q,

					     struct bio *bio)

{

	struct bio_vec uninitialized_var(bv), bvprv = { NULL };

	unsigned int seg_size, nr_phys_segs;

	unsigned front_seg_size;

	struct bio *fbio, *bbio;

	unsigned int nr_phys_segs = 0;

	struct bvec_iter iter;

	struct bio_vec bv;



	if (!bio)

		return 0;



	front_seg_size = bio->bi_seg_front_size;



	switch (bio_op(bio)) {

	case REQ_OP_DISCARD:

	case REQ_OP_SECURE_ERASE:
@@ -356,23 +325,11 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q, 
		return 1;

	}



	fbio = bio;

	seg_size = 0;

	nr_phys_segs = 0;

	for_each_bio(bio) {

		bio_for_each_bvec(bv, bio, iter) {

			bvec_split_segs(q, &bv, &nr_phys_segs, &seg_size,

					&front_seg_size, NULL, UINT_MAX);

		}

		bbio = bio;

		if (likely(bio->bi_iter.bi_size))

			bvprv = bv;

		bio_for_each_bvec(bv, bio, iter)

			bvec_split_segs(q, &bv, &nr_phys_segs, NULL, UINT_MAX);

	}



	fbio->bi_seg_front_size = front_seg_size;

	if (seg_size > bbio->bi_seg_back_size)

		bbio->bi_seg_back_size = seg_size;



	return nr_phys_segs;

}
@@ -392,24 +349,6 @@ void blk_recount_segments(struct request_queue *q, struct bio *bio) 
	bio_set_flag(bio, BIO_SEG_VALID);

}



static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,

				   struct bio *nxt)

{

	struct bio_vec end_bv = { NULL }, nxt_bv;



	if (bio->bi_seg_back_size + nxt->bi_seg_front_size >

	    queue_max_segment_size(q))

		return 0;



	if (!bio_has_data(bio))

		return 1;



	bio_get_last_bvec(bio, &end_bv);

	bio_get_first_bvec(nxt, &nxt_bv);



	return biovec_phys_mergeable(q, &end_bv, &nxt_bv);

}



static inline struct scatterlist *blk_next_sg(struct scatterlist **sg,

		struct scatterlist *sglist)

{
@@ -669,8 +608,6 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, 
				struct request *next)

{

	int total_phys_segments;

	unsigned int seg_size =

		req->biotail->bi_seg_back_size + next->bio->bi_seg_front_size;



	if (req_gap_back_merge(req, next->bio))

		return 0;
@@ -683,13 +620,6 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, 
		return 0;



	total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;

	if (blk_phys_contig_segment(q, req->biotail, next->bio)) {

		if (req->nr_phys_segments == 1)

			req->bio->bi_seg_front_size = seg_size;

		if (next->nr_phys_segments == 1)

			next->biotail->bi_seg_back_size = seg_size;

	}



	if (total_phys_segments > queue_max_segments(q))

		return 0;

include/linux/blk_types.h

+0 −7
Original line number Diff line number Diff line
@@ -159,13 +159,6 @@ struct bio { 
	 */

	unsigned int		bi_phys_segments;



	/*

	 * To keep track of the max segment size, we account for the

	 * sizes of the first and last mergeable segments in this bio.

	 */

	unsigned int		bi_seg_front_size;

	unsigned int		bi_seg_back_size;



	struct bvec_iter	bi_iter;



	atomic_t		__bi_remaining;