From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 22 May 2018 10:28:14 +0800 From: Ming Lei To: Keith Busch Cc: Jens Axboe , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, Christoph Hellwig , Bart Van Assche Subject: Re: [RFC PATCH 2/3] blk-mq: Fix timeout and state order Message-ID: <20180522022813.GC20430@ming.t460p> References: <20180521231131.6685-1-keith.busch@intel.com> <20180521231131.6685-3-keith.busch@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180521231131.6685-3-keith.busch@intel.com> List-ID: On Mon, May 21, 2018 at 05:11:30PM -0600, Keith Busch wrote: > The block layer had been setting the state to in-flight prior to updating > the timer. This is the wrong order since the timeout handler could observe > the in-flight state with the older timeout, believing the request had > expired when in fact it is just getting started. > > Signed-off-by: Keith Busch > --- > block/blk-mq.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 8b370ed75605..66e5c768803f 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -713,8 +713,8 @@ void blk_mq_start_request(struct request *rq) > preempt_disable(); > write_seqcount_begin(&rq->gstate_seq); > > - blk_mq_rq_update_state(rq, MQ_RQ_IN_FLIGHT); > blk_add_timer(rq); > + blk_mq_rq_update_state(rq, MQ_RQ_IN_FLIGHT); > > write_seqcount_end(&rq->gstate_seq); > preempt_enable(); > -- > 2.14.3 > Looks fine, Reviewed-by: Ming Lei Thanks, Ming