From mboxrd@z Thu Jan 1 00:00:00 1970 From: bart.vanassche@sandisk.com (Bart Van Assche) Date: Tue, 11 Oct 2016 17:41:03 -0700 Subject: [PATCH v2 7/7] [RFC] nvme: Fix a race condition In-Reply-To: <20161011164601.GC18822@lst.de> References: <20161011164601.GC18822@lst.de> Message-ID: <28847fd5-630d-4ac9-c96f-9b27a05323cd@sandisk.com> On 10/11/16 09:46, Christoph Hellwig wrote: > On Wed, Sep 28, 2016@05:01:45PM -0700, Bart Van Assche wrote: >> Avoid that nvme_queue_rq() is still running when nvme_stop_queues() >> returns. Untested. >> >> Signed-off-by: Bart Van Assche >> Cc: Keith Busch >> Cc: Christoph Hellwig >> Cc: Sagi Grimberg >> --- >> drivers/nvme/host/core.c | 20 ++++++++++++-------- >> 1 file changed, 12 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c >> index d791fba..98f1f29 100644 >> --- a/drivers/nvme/host/core.c >> +++ b/drivers/nvme/host/core.c >> @@ -201,13 +201,9 @@ fail: >> >> void nvme_requeue_req(struct request *req) >> { >> - unsigned long flags; >> - >> blk_mq_requeue_request(req); >> - spin_lock_irqsave(req->q->queue_lock, flags); >> - if (!blk_mq_queue_stopped(req->q)) >> - blk_mq_kick_requeue_list(req->q); >> - spin_unlock_irqrestore(req->q->queue_lock, flags); >> + WARN_ON_ONCE(blk_mq_queue_stopped(req->q)); >> + blk_mq_kick_requeue_list(req->q); >> } >> EXPORT_SYMBOL_GPL(nvme_requeue_req); > > Can we just add a 'bool kick' argument to blk_mq_requeue_request and > move all this handling to the core? Hello Christoph, That sounds like a good idea to me. Thanks also for the other review comments you posted on this patch series. I will rework patch 6/7 such that the code for waiting is moved into the SCSI core. Bart.