blk-mq: check bio_mergeable() early before merging
authorMing Lei <ming.lei@canonical.com>
Tue, 20 Oct 2015 15:13:54 +0000 (23:13 +0800)
committerJens Axboe <axboe@fb.com>
Wed, 21 Oct 2015 21:00:53 +0000 (15:00 -0600)
It isn't necessary to try to merge the bio which is marked
as NOMERGE.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
block/blk-mq.c

index 9683a561efcd73a9e1e38a6909e6edae23c97b9b..d38371160019ca17468478d30a5c8f1792f5e109 100644 (file)
@@ -1140,7 +1140,7 @@ static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx,
                                         struct blk_mq_ctx *ctx,
                                         struct request *rq, struct bio *bio)
 {
-       if (!hctx_allow_merges(hctx)) {
+       if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) {
                blk_mq_bio_to_request(rq, bio);
                spin_lock(&ctx->lock);
 insert_rq: