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-rw-r--r--block/blk-merge.c31
-rw-r--r--block/blk.h4
2 files changed, 18 insertions, 17 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 6aa43dec5af4..3826fc32b72c 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -659,31 +659,32 @@ static void blk_account_io_merge(struct request *req)
}
/*
- * Has to be called with the request spinlock acquired
+ * 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.
*/
-static int attempt_merge(struct request_queue *q, struct request *req,
- struct request *next)
+static struct request *attempt_merge(struct request_queue *q,
+ struct request *req, struct request *next)
{
if (!rq_mergeable(req) || !rq_mergeable(next))
- return 0;
+ return NULL;
if (req_op(req) != req_op(next))
- return 0;
+ return NULL;
/*
* not contiguous
*/
if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))
- return 0;
+ return NULL;
if (rq_data_dir(req) != rq_data_dir(next)
|| req->rq_disk != next->rq_disk
|| req_no_special_merge(next))
- return 0;
+ return NULL;
if (req_op(req) == REQ_OP_WRITE_SAME &&
!blk_write_same_mergeable(req->bio, next->bio))
- return 0;
+ return NULL;
/*
* If we are allowed to merge, then append bio list
@@ -692,7 +693,7 @@ static int attempt_merge(struct request_queue *q, struct request *req,
* counts here.
*/
if (!ll_merge_requests_fn(q, req, next))
- return 0;
+ return NULL;
/*
* If failfast settings disagree or any of the two is already
@@ -735,27 +736,27 @@ static int attempt_merge(struct request_queue *q, struct request *req,
/* owner-ship of bio passed from next to req */
next->bio = NULL;
__blk_put_request(q, next);
- return 1;
+ return next;
}
-int attempt_back_merge(struct request_queue *q, struct request *rq)
+struct request *attempt_back_merge(struct request_queue *q, struct request *rq)
{
struct request *next = elv_latter_request(q, rq);
if (next)
return attempt_merge(q, rq, next);
- return 0;
+ return NULL;
}
-int attempt_front_merge(struct request_queue *q, struct request *rq)
+struct request *attempt_front_merge(struct request_queue *q, struct request *rq)
{
struct request *prev = elv_former_request(q, rq);
if (prev)
return attempt_merge(q, prev, rq);
- return 0;
+ return NULL;
}
int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
@@ -767,7 +768,7 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
if (!e->type->ops.sq.elevator_allow_rq_merge_fn(q, rq, next))
return 0;
- return attempt_merge(q, rq, next);
+ return attempt_merge(q, rq, next) != NULL;
}
bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
diff --git a/block/blk.h b/block/blk.h
index 6aa53a4aad88..4972b98d47e1 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -208,8 +208,8 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
struct bio *bio);
int ll_front_merge_fn(struct request_queue *q, struct request *req,
struct bio *bio);
-int attempt_back_merge(struct request_queue *q, struct request *rq);
-int attempt_front_merge(struct request_queue *q, struct request *rq);
+struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
+struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
struct request *next);
void blk_recalc_rq_segments(struct request *rq);