From 2edd2c740b2918eb0a9a1fe1b69678b903769ec2 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 17 Sep 2014 17:47:58 +0800 Subject: [PATCH] blk-mq: remove unnecessary blk_clear_rq_complete() This patch removes two unnecessary blk_clear_rq_complete(), the REQ_ATOM_COMPLETE flag is cleared inside blk_mq_start_request(), so: - The blk_clear_rq_complete() in blk_flush_restore_request() needn't because the request will be freed later, and clearing it here may open a small race window with timeout. - The blk_clear_rq_complete() in blk_mq_requeue_request() isn't necessary too, even though REQ_ATOM_STARTED is cleared in __blk_mq_requeue_request(), in theory it still may cause a small race window with timeout since the two clear_bit() may be reordered. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-flush.c | 2 -- block/blk-mq.c | 1 - 2 files changed, 3 deletions(-) diff --git a/block/blk-flush.c b/block/blk-flush.c index 698e6926388c..c8e25768f2e1 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -126,8 +126,6 @@ static void blk_flush_restore_request(struct request *rq) /* make @rq a normal request */ rq->cmd_flags &= ~REQ_FLUSH_SEQ; rq->end_io = rq->flush.saved_end_io; - - blk_clear_rq_complete(rq); } static bool blk_flush_queue_rq(struct request *rq, bool add_front) diff --git a/block/blk-mq.c b/block/blk-mq.c index d12f1983d493..3b277b4eaa95 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -439,7 +439,6 @@ static void __blk_mq_requeue_request(struct request *rq) void blk_mq_requeue_request(struct request *rq) { __blk_mq_requeue_request(rq); - blk_clear_rq_complete(rq); BUG_ON(blk_queued_rq(rq)); blk_mq_add_to_requeue_list(rq, true); -- 2.20.1