[PATCH 2/5] block: Remove redundant blk_mq_sched_allow_merge() validation

[Baolin Wang]

Only software queue and kyber IO scheduler will call blk_mq_bio_list_merge()
to merge a bio, and kyber IO scheduler did not implement the ops->allow_merge().
Thus we can remove the redundant blk_mq_sched_allow_merge() in
blk_mq_bio_list_merge() function.

Signed-off-by: Baolin Wang <baolin.w...@linux.alibaba.com>
---
 block/blk-mq-sched.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index b8db72c..cc34f69 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -403,14 +403,10 @@ bool blk_mq_bio_list_merge(struct request_queue *q, 
struct list_head *list,
 
                switch (blk_try_merge(rq, bio)) {
                case ELEVATOR_BACK_MERGE:
-                       if (blk_mq_sched_allow_merge(q, rq, bio))
-                               merged = bio_attempt_back_merge(rq, bio,
-                                               nr_segs);
+                       merged = bio_attempt_back_merge(rq, bio, nr_segs);
                        break;
                case ELEVATOR_FRONT_MERGE:
-                       if (blk_mq_sched_allow_merge(q, rq, bio))
-                               merged = bio_attempt_front_merge(rq, bio,
-                                               nr_segs);
+                       merged = bio_attempt_front_merge(rq, bio, nr_segs);
                        break;
                case ELEVATOR_DISCARD_MERGE:
                        merged = bio_attempt_discard_merge(q, rq, bio);
-- 
1.8.3.1