Merge branch 'for-4.4/core' of git://git.kernel.dk/linux-block

[deliverable/linux.git] / block / blk-merge.c

diff --git a/block/blk-merge.c b/block/blk-merge.c
index d088cffb810508a5e55f7543bc134537329d00ec..de5716d8e525969e7849767a775aabec9e4d8b96 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -11,13 +11,16 @@
 
 static struct bio *blk_bio_discard_split(struct request_queue *q,
                                         struct bio *bio,
-                                        struct bio_set *bs)
+                                        struct bio_set *bs,
+                                        unsigned *nsegs)
 {
        unsigned int max_discard_sectors, granularity;
        int alignment;
        sector_t tmp;
        unsigned split_sectors;
 
+       *nsegs = 1;
+
        /* Zero-sector (unknown) and one-sector granularities are the same.  */
        granularity = max(q->limits.discard_granularity >> 9, 1U);
 
@@ -51,8 +54,11 @@ static struct bio *blk_bio_discard_split(struct request_queue *q,
 
 static struct bio *blk_bio_write_same_split(struct request_queue *q,
                                            struct bio *bio,
-                                           struct bio_set *bs)
+                                           struct bio_set *bs,
+                                           unsigned *nsegs)
 {
+       *nsegs = 1;
+
        if (!q->limits.max_write_same_sectors)
                return NULL;
 
@@ -64,38 +70,36 @@ static struct bio *blk_bio_write_same_split(struct request_queue *q,
 
 static struct bio *blk_bio_segment_split(struct request_queue *q,
                                         struct bio *bio,
-                                        struct bio_set *bs)
+                                        struct bio_set *bs,
+                                        unsigned *segs)
 {
-       struct bio *split;
-       struct bio_vec bv, bvprv;
+       struct bio_vec bv, bvprv, *bvprvp = NULL;
        struct bvec_iter iter;
        unsigned seg_size = 0, nsegs = 0, sectors = 0;
-       int prev = 0;
 
        bio_for_each_segment(bv, bio, iter) {
-               sectors += bv.bv_len >> 9;
-
-               if (sectors > queue_max_sectors(q))
+               if (sectors + (bv.bv_len >> 9) > queue_max_sectors(q))
                        goto split;
 
                /*
                 * If the queue doesn't support SG gaps and adding this
                 * offset would create a gap, disallow it.
                 */
-               if (prev && bvec_gap_to_prev(q, &bvprv, bv.bv_offset))
+               if (bvprvp && bvec_gap_to_prev(q, bvprvp, bv.bv_offset))
                        goto split;
 
-               if (prev && blk_queue_cluster(q)) {
+               if (bvprvp && blk_queue_cluster(q)) {
                        if (seg_size + bv.bv_len > queue_max_segment_size(q))
                                goto new_segment;
-                       if (!BIOVEC_PHYS_MERGEABLE(&bvprv, &bv))
+                       if (!BIOVEC_PHYS_MERGEABLE(bvprvp, &bv))
                                goto new_segment;
-                       if (!BIOVEC_SEG_BOUNDARY(q, &bvprv, &bv))
+                       if (!BIOVEC_SEG_BOUNDARY(q, bvprvp, &bv))
                                goto new_segment;
 
                        seg_size += bv.bv_len;
                        bvprv = bv;
-                       prev = 1;
+                       bvprvp = &bv;
+                       sectors += bv.bv_len >> 9;
                        continue;
                }
 new_segment:
@@ -104,38 +108,40 @@ new_segment:
 
                nsegs++;
                bvprv = bv;
-               prev = 1;
+               bvprvp = &bv;
                seg_size = bv.bv_len;
+               sectors += bv.bv_len >> 9;
        }
 
+       *segs = nsegs;
        return NULL;
 split:
-       split = bio_clone_bioset(bio, GFP_NOIO, bs);
-
-       split->bi_iter.bi_size -= iter.bi_size;
-       bio->bi_iter = iter;
-
-       if (bio_integrity(bio)) {
-               bio_integrity_advance(bio, split->bi_iter.bi_size);
-               bio_integrity_trim(split, 0, bio_sectors(split));
-       }
-
-       return split;
+       *segs = nsegs;
+       return bio_split(bio, sectors, GFP_NOIO, bs);
 }
 
 void blk_queue_split(struct request_queue *q, struct bio **bio,
                     struct bio_set *bs)
 {
-       struct bio *split;
+       struct bio *split, *res;
+       unsigned nsegs;
 
        if ((*bio)->bi_rw & REQ_DISCARD)
-               split = blk_bio_discard_split(q, *bio, bs);
+               split = blk_bio_discard_split(q, *bio, bs, &nsegs);
        else if ((*bio)->bi_rw & REQ_WRITE_SAME)
-               split = blk_bio_write_same_split(q, *bio, bs);
+               split = blk_bio_write_same_split(q, *bio, bs, &nsegs);
        else
-               split = blk_bio_segment_split(q, *bio, q->bio_split);
+               split = blk_bio_segment_split(q, *bio, q->bio_split, &nsegs);
+
+       /* physical segments can be figured out during splitting */
+       res = split ? split : *bio;
+       res->bi_phys_segments = nsegs;
+       bio_set_flag(res, BIO_SEG_VALID);
 
        if (split) {
+               /* there isn't chance to merge the splitted bio */
+               split->bi_rw |= REQ_NOMERGE;
+
                bio_chain(split, *bio);
                generic_make_request(*bio);
                *bio = split;
@@ -439,6 +445,11 @@ no_merge:
 int ll_back_merge_fn(struct request_queue *q, struct request *req,
                     struct bio *bio)
 {
+       if (req_gap_back_merge(req, bio))
+               return 0;
+       if (blk_integrity_rq(req) &&
+           integrity_req_gap_back_merge(req, bio))
+               return 0;
        if (blk_rq_sectors(req) + bio_sectors(bio) >
            blk_rq_get_max_sectors(req)) {
                req->cmd_flags |= REQ_NOMERGE;
@@ -457,6 +468,12 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
 int ll_front_merge_fn(struct request_queue *q, struct request *req,
                      struct bio *bio)
 {
+
+       if (req_gap_front_merge(req, bio))
+               return 0;
+       if (blk_integrity_rq(req) &&
+           integrity_req_gap_front_merge(req, bio))
+               return 0;
        if (blk_rq_sectors(req) + bio_sectors(bio) >
            blk_rq_get_max_sectors(req)) {
                req->cmd_flags |= REQ_NOMERGE;
@@ -483,14 +500,6 @@ static bool req_no_special_merge(struct request *req)
        return !q->mq_ops && req->special;
 }
 
-static int req_gap_to_prev(struct request *req, struct bio *next)
-{
-       struct bio *prev = req->biotail;
-
-       return bvec_gap_to_prev(req->q, &prev->bi_io_vec[prev->bi_vcnt - 1],
-                       next->bi_io_vec[0].bv_offset);
-}
-
 static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
                                struct request *next)
 {
@@ -505,7 +514,7 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
        if (req_no_special_merge(req) || req_no_special_merge(next))
                return 0;
 
-       if (req_gap_to_prev(req, next->bio))
+       if (req_gap_back_merge(req, next->bio))
                return 0;
 
        /*
@@ -713,10 +722,6 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
            !blk_write_same_mergeable(rq->bio, bio))
                return false;
 
-       /* Only check gaps if the bio carries data */
-       if (bio_has_data(bio) && req_gap_to_prev(rq, bio))
-               return false;
-
        return true;
 }