diff --git a/block/blk-core.c b/block/blk-core.c index fe81e19099a13dbb1a4876f61f437886e2e85232..5b6f768a7c01ae5ab87c44302dddeb326b20b775 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1471,6 +1471,8 @@ bool bio_attempt_front_merge(struct request_queue *q, struct request *req, * added on the elevator at this point. In addition, we don't have * reliable access to the elevator outside queue lock. Only check basic * merging parameters without querying the elevator. + * + * Caller must ensure !blk_queue_nomerges(q) beforehand. */ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, unsigned int *request_count) @@ -1480,9 +1482,6 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, bool ret = false; struct list_head *plug_list; - if (blk_queue_nomerges(q)) - goto out; - plug = current->plug; if (!plug) goto out; @@ -1561,7 +1560,8 @@ void blk_queue_bio(struct request_queue *q, struct bio *bio) * Check if we can merge with the plugged list before grabbing * any locks. */ - if (blk_attempt_plug_merge(q, bio, &request_count)) + if (!blk_queue_nomerges(q) && + blk_attempt_plug_merge(q, bio, &request_count)) return; spin_lock_irq(q->queue_lock); diff --git a/block/blk-mq.c b/block/blk-mq.c index fec8fcc4f8a4ea0f3a866bc4feaae6feb73eb4f5..ef7ed5e95d6d7587c0b69ce36f0e91d4b2bef31a 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1087,7 +1087,8 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio) return; } - if (use_plug && blk_attempt_plug_merge(q, bio, &request_count)) + if (use_plug && !blk_queue_nomerges(q) && + blk_attempt_plug_merge(q, bio, &request_count)) return; if (blk_mq_queue_enter(q)) {