From 6869875fbc04042ad01654591da60862706e86e3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 21 May 2019 09:01:43 +0200 Subject: [PATCH] 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: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-merge.c | 94 ++++++----------------------------------------- include/linux/blk_types.h | 7 ---- 2 files changed, 12 insertions(+), 89 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index eee2c02..17713d7 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -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; @@ -185,28 +184,12 @@ 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; + if (new_nsegs) { + *nsegs += new_nsegs; + if (sectors) + *sectors += total_len >> 9; } - /* update other varibles */ - *last_seg_size = seg_size; - *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, §ors, 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, §ors, max_segs)) { + } else if (bvec_split_segs(q, &bv, &nsegs, §ors, + max_segs)) { goto split; } } @@ -278,10 +255,6 @@ split: 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; diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index be41827..95202f8 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -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; -- 2.7.4