1 files changed, 25 insertions, 46 deletions

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 0e871d4e7cb8..7771dacc99cb 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -9,6 +9,7 @@
 #include <linux/blk-integrity.h>
 #include <linux/scatterlist.h>
 #include <linux/part_stat.h>
+#include <linux/blk-cgroup.h>
 
 #include <trace/events/block.h>
 
@@ -152,22 +153,6 @@ static struct bio *blk_bio_write_zeroes_split(struct request_queue *q,
 	return bio_split(bio, q->limits.max_write_zeroes_sectors, GFP_NOIO, bs);
 }
 
-static struct bio *blk_bio_write_same_split(struct request_queue *q,
-					    struct bio *bio,
-					    struct bio_set *bs,
-					    unsigned *nsegs)
-{
-	*nsegs = 1;
-
-	if (!q->limits.max_write_same_sectors)
-		return NULL;
-
-	if (bio_sectors(bio) <= q->limits.max_write_same_sectors)
-		return NULL;
-
-	return bio_split(bio, q->limits.max_write_same_sectors, GFP_NOIO, bs);
-}
-
 /*
  * Return the maximum number of sectors from the start of a bio that may be
  * submitted as a single request to a block device. If enough sectors remain,
@@ -351,10 +336,6 @@ void __blk_queue_split(struct request_queue *q, struct bio **bio,
 		split = blk_bio_write_zeroes_split(q, *bio, &q->bio_split,
 				nr_segs);
 		break;
-	case REQ_OP_WRITE_SAME:
-		split = blk_bio_write_same_split(q, *bio, &q->bio_split,
-				nr_segs);
-		break;
 	default:
 		split = blk_bio_segment_split(q, *bio, &q->bio_split, nr_segs);
 		break;
@@ -414,8 +395,6 @@ unsigned int blk_recalc_rq_segments(struct request *rq)
 		return 1;
 	case REQ_OP_WRITE_ZEROES:
 		return 0;
-	case REQ_OP_WRITE_SAME:
-		return 1;
 	}
 
 	rq_for_each_bvec(bv, rq, iter)
@@ -553,8 +532,6 @@ int __blk_rq_map_sg(struct request_queue *q, struct request *rq,
 
 	if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
 		nsegs = __blk_bvec_map_sg(rq->special_vec, sglist, last_sg);
-	else if (rq->bio && bio_op(rq->bio) == REQ_OP_WRITE_SAME)
-		nsegs = __blk_bvec_map_sg(bio_iovec(rq->bio), sglist, last_sg);
 	else if (rq->bio)
 		nsegs = __blk_bios_map_sg(q, rq->bio, sglist, last_sg);
 
@@ -598,6 +575,9 @@ static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
 static inline int ll_new_hw_segment(struct request *req, struct bio *bio,
 		unsigned int nr_phys_segs)
 {
+	if (!blk_cgroup_mergeable(req, bio))
+		goto no_merge;
+
 	if (blk_integrity_merge_bio(req->q, req, bio) == false)
 		goto no_merge;
 
@@ -694,6 +674,9 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
 	if (total_phys_segments > blk_rq_get_max_segments(req))
 		return 0;
 
+	if (!blk_cgroup_mergeable(req, next->bio))
+		return 0;
+
 	if (blk_integrity_merge_rq(q, req, next) == false)
 		return 0;
 
@@ -755,13 +738,6 @@ static enum elv_merge blk_try_req_merge(struct request *req,
 	return ELEVATOR_NO_MERGE;
 }
 
-static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b)
-{
-	if (bio_page(a) == bio_page(b) && bio_offset(a) == bio_offset(b))
-		return true;
-	return false;
-}
-
 /*
  * For non-mq, this has to be called with the request spinlock acquired.
  * For mq with scheduling, the appropriate queue wide lock should be held.
@@ -778,10 +754,6 @@ static struct request *attempt_merge(struct request_queue *q,
 	if (rq_data_dir(req) != rq_data_dir(next))
 		return NULL;
 
-	if (req_op(req) == REQ_OP_WRITE_SAME &&
-	    !blk_write_same_mergeable(req->bio, next->bio))
-		return NULL;
-
 	if (req->ioprio != next->ioprio)
 		return NULL;
 
@@ -895,6 +867,10 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 	if (bio_data_dir(bio) != rq_data_dir(rq))
 		return false;
 
+	/* don't merge across cgroup boundaries */
+	if (!blk_cgroup_mergeable(rq, bio))
+		return false;
+
 	/* only merge integrity protected bio into ditto rq */
 	if (blk_integrity_merge_bio(rq->q, rq, bio) == false)
 		return false;
@@ -903,11 +879,6 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 	if (!bio_crypt_rq_ctx_compatible(rq, bio))
 		return false;
 
-	/* must be using the same buffer */
-	if (req_op(rq) == REQ_OP_WRITE_SAME &&
-	    !blk_write_same_mergeable(rq->bio, bio))
-		return false;
-
 	if (rq->ioprio != bio_prio(bio))
 		return false;
 
@@ -1073,12 +1044,20 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 	if (!plug || rq_list_empty(plug->mq_list))
 		return false;
 
-	/* check the previously added entry for a quick merge attempt */
-	rq = rq_list_peek(&plug->mq_list);
-	if (rq->q == q) {
-		if (blk_attempt_bio_merge(q, rq, bio, nr_segs, false) ==
-				BIO_MERGE_OK)
-			return true;
+	rq_list_for_each(&plug->mq_list, rq) {
+		if (rq->q == q) {
+			if (blk_attempt_bio_merge(q, rq, bio, nr_segs, false) ==
+			    BIO_MERGE_OK)
+				return true;
+			break;
+		}
+
+		/*
+		 * Only keep iterating plug list for merges if we have multiple
+		 * queues
+		 */
+		if (!plug->multiple_queues)
+			break;
 	}
 	return false;
 }