1 files changed, 63 insertions, 130 deletions

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 936a110de0b..cfcc37cb222 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -110,49 +110,6 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
         return 0;
 }
 
-static void
-__blk_segment_map_sg(struct request_queue *q, struct bio_vec *bvec,
-                     struct scatterlist *sglist, struct bio_vec **bvprv,
-                     struct scatterlist **sg, int *nsegs, int *cluster)
-{
-
-        int nbytes = bvec->bv_len;
-
-        if (*bvprv && *cluster) {
-                if ((*sg)->length + nbytes > queue_max_segment_size(q))
-                        goto new_segment;
-
-                if (!BIOVEC_PHYS_MERGEABLE(*bvprv, bvec))
-                        goto new_segment;
-                if (!BIOVEC_SEG_BOUNDARY(q, *bvprv, bvec))
-                        goto new_segment;
-
-                (*sg)->length += nbytes;
-        } else {
-new_segment:
-                if (!*sg)
-                        *sg = sglist;
-                else {
-                        /*
-                         * If the driver previously mapped a shorter
-                         * list, we could see a termination bit
-                         * prematurely unless it fully inits the sg
-                         * table on each mapping. We KNOW that there
-                         * must be more entries here or the driver
-                         * would be buggy, so force clear the
-                         * termination bit to avoid doing a full
-                         * sg_init_table() in drivers for each command.
-                         */
-                        (*sg)->page_link &= ~0x02;
-                        *sg = sg_next(*sg);
-                }
-
-                sg_set_page(*sg, bvec->bv_page, nbytes, bvec->bv_offset);
-                (*nsegs)++;
-        }
-        *bvprv = bvec;
-}
-
 /*
  * map a request to scatterlist, return number of sg entries setup. Caller
  * must make sure sg can hold rq->nr_phys_segments entries
@@ -174,8 +131,41 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
         bvprv = NULL;
         sg = NULL;
         rq_for_each_segment(bvec, rq, iter) {
-                __blk_segment_map_sg(q, bvec, sglist, &bvprv, &sg,
-                                     &nsegs, &cluster);
+                int nbytes = bvec->bv_len;
+
+                if (bvprv && cluster) {
+                        if (sg->length + nbytes > queue_max_segment_size(q))
+                                goto new_segment;
+
+                        if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec))
+                                goto new_segment;
+                        if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bvec))
+                                goto new_segment;
+
+                        sg->length += nbytes;
+                } else {
+new_segment:
+                        if (!sg)
+                                sg = sglist;
+                        else {
+                                /*
+                                 * If the driver previously mapped a shorter
+                                 * list, we could see a termination bit
+                                 * prematurely unless it fully inits the sg
+                                 * table on each mapping. We KNOW that there
+                                 * must be more entries here or the driver
+                                 * would be buggy, so force clear the
+                                 * termination bit to avoid doing a full
+                                 * sg_init_table() in drivers for each command.
+                                 */
+                                sg->page_link &= ~0x02;
+                                sg = sg_next(sg);
+                        }
+
+                        sg_set_page(sg, bvec->bv_page, nbytes, bvec->bv_offset);
+                        nsegs++;
+                }
+                bvprv = bvec;
         } /* segments in rq */
 
 
@@ -209,43 +199,6 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
 }
 EXPORT_SYMBOL(blk_rq_map_sg);
 
-/**
- * blk_bio_map_sg - map a bio to a scatterlist
- * @q: request_queue in question
- * @bio: bio being mapped
- * @sglist: scatterlist being mapped
- *
- * Note:
- *    Caller must make sure sg can hold bio->bi_phys_segments entries
- *
- * Will return the number of sg entries setup
- */
-int blk_bio_map_sg(struct request_queue *q, struct bio *bio,
-                   struct scatterlist *sglist)
-{
-        struct bio_vec *bvec, *bvprv;
-        struct scatterlist *sg;
-        int nsegs, cluster;
-        unsigned long i;
-
-        nsegs = 0;
-        cluster = blk_queue_cluster(q);
-
-        bvprv = NULL;
-        sg = NULL;
-        bio_for_each_segment(bvec, bio, i) {
-                __blk_segment_map_sg(q, bvec, sglist, &bvprv, &sg,
-                                     &nsegs, &cluster);
-        } /* segments in bio */
-
-        if (sg)
-                sg_mark_end(sg);
-
-        BUG_ON(bio->bi_phys_segments && nsegs > bio->bi_phys_segments);
-        return nsegs;
-}
-EXPORT_SYMBOL(blk_bio_map_sg);
-
 static inline int ll_new_hw_segment(struct request_queue *q,
                                     struct request *req,
                                     struct bio *bio)
@@ -275,8 +228,14 @@ no_merge:
 int ll_back_merge_fn(struct request_queue *q, struct request *req,
                      struct bio *bio)
 {
-        if (blk_rq_sectors(req) + bio_sectors(bio) >
-            blk_rq_get_max_sectors(req)) {
+        unsigned short max_sectors;
+
+        if (unlikely(req->cmd_type == REQ_TYPE_BLOCK_PC))
+                max_sectors = queue_max_hw_sectors(q);
+        else
+                max_sectors = queue_max_sectors(q);
+
+        if (blk_rq_sectors(req) + bio_sectors(bio) > max_sectors) {
                 req->cmd_flags |= REQ_NOMERGE;
                 if (req == q->last_merge)
                         q->last_merge = NULL;
@@ -293,8 +252,15 @@ 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 (blk_rq_sectors(req) + bio_sectors(bio) >
-            blk_rq_get_max_sectors(req)) {
+        unsigned short max_sectors;
+
+        if (unlikely(req->cmd_type == REQ_TYPE_BLOCK_PC))
+                max_sectors = queue_max_hw_sectors(q);
+        else
+                max_sectors = queue_max_sectors(q);
+
+
+        if (blk_rq_sectors(req) + bio_sectors(bio) > max_sectors) {
                 req->cmd_flags |= REQ_NOMERGE;
                 if (req == q->last_merge)
                         q->last_merge = NULL;
@@ -325,8 +291,7 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
         /*
          * Will it become too large?
          */
-        if ((blk_rq_sectors(req) + blk_rq_sectors(next)) >
-            blk_rq_get_max_sectors(req))
+        if ((blk_rq_sectors(req) + blk_rq_sectors(next)) > queue_max_sectors(q))
                 return 0;
 
         total_phys_segments = req->nr_phys_segments + next->nr_phys_segments;
@@ -405,7 +370,16 @@ static int attempt_merge(struct request_queue *q, struct request *req,
         if (!rq_mergeable(req) || !rq_mergeable(next))
                 return 0;
 
-        if (!blk_check_merge_flags(req->cmd_flags, next->cmd_flags))
+        /*
+         * Don't merge file system requests and discard requests
+         */
+        if ((req->cmd_flags & REQ_DISCARD) != (next->cmd_flags & REQ_DISCARD))
+                return 0;
+
+        /*
+         * Don't merge discard requests and secure discard requests
+         */
+        if ((req->cmd_flags & REQ_SECURE) != (next->cmd_flags & REQ_SECURE))
                 return 0;
 
         /*
@@ -419,10 +393,6 @@ static int attempt_merge(struct request_queue *q, struct request *req,
             || next->special)
                 return 0;
 
-        if (req->cmd_flags & REQ_WRITE_SAME &&
-            !blk_write_same_mergeable(req->bio, next->bio))
-                return 0;
-
         /*
          * If we are allowed to merge, then append bio list
          * from next to rq and release next. merge_requests_fn
@@ -501,40 +471,3 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
 {
         return attempt_merge(q, rq, next);
 }
-
-bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
-{
-        if (!rq_mergeable(rq) || !bio_mergeable(bio))
-                return false;
-
-        if (!blk_check_merge_flags(rq->cmd_flags, bio->bi_rw))
-                return false;
-
-        /* different data direction or already started, don't merge */
-        if (bio_data_dir(bio) != rq_data_dir(rq))
-                return false;
-
-        /* must be same device and not a special request */
-        if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special)
-                return false;
-
-        /* only merge integrity protected bio into ditto rq */
-        if (bio_integrity(bio) != blk_integrity_rq(rq))
-                return false;
-
-        /* must be using the same buffer */
-        if (rq->cmd_flags & REQ_WRITE_SAME &&
-            !blk_write_same_mergeable(rq->bio, bio))
-                return false;
-
-        return true;
-}
-
-int blk_try_merge(struct request *rq, struct bio *bio)
-{
-        if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_sector)
-                return ELEVATOR_BACK_MERGE;
-        else if (blk_rq_pos(rq) - bio_sectors(bio) == bio->bi_sector)
-                return ELEVATOR_FRONT_MERGE;
-        return ELEVATOR_NO_MERGE;
-}