On Tue, May 21, 2019 at 09:01:43AM +0200, Christoph Hellwig wrote:
> At this point these fields aren't used for anything, so we can remove
> them.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
> ---
> 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 eee2c02c50ce..17713d7d98d5 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 @@ 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;
>
> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
> index be418275763c..95202f80676c 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;
> --
> 2.20.1
>
Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
Thanks,
Ming
