From mboxrd@z Thu Jan 1 00:00:00 1970 From: ming.lei@redhat.com (Ming Lei) Date: Tue, 23 Jul 2019 09:08:46 +0800 Subject: [PATCH 3/5] nvme: don't abort completed request in nvme_cancel_request In-Reply-To: References: <20190722053954.25423-1-ming.lei@redhat.com> <20190722053954.25423-4-ming.lei@redhat.com> Message-ID: <20190723010845.GD30776@ming.t460p> On Mon, Jul 22, 2019@08:27:32AM -0700, Bart Van Assche wrote: > On 7/21/19 10:39 PM, Ming Lei wrote: > > Before aborting in-flight requests, all IO queues have been shutdown. > > However, request's completion fn may not be done yet because it may > > be scheduled to run via IPI. > > > > So don't abort one request if it is marked as completed, otherwise > > we may abort one normal completed request. > > > > Cc: Max Gurtovoy > > Cc: Sagi Grimberg > > Cc: Keith Busch > > Cc: Christoph Hellwig > > Signed-off-by: Ming Lei > > --- > > drivers/nvme/host/core.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c > > index cc09b81fc7f4..cb8007cce4d1 100644 > > --- a/drivers/nvme/host/core.c > > +++ b/drivers/nvme/host/core.c > > @@ -285,6 +285,10 @@ EXPORT_SYMBOL_GPL(nvme_complete_rq); > > bool nvme_cancel_request(struct request *req, void *data, bool reserved) > > { > > + /* don't abort one completed request */ > > + if (blk_mq_request_completed(req)) > > + return; > > + > > dev_dbg_ratelimited(((struct nvme_ctrl *) data)->device, > > "Cancelling I/O %d", req->tag); > > Something I probably already asked before: what prevents that > nvme_cancel_request() is executed concurrently with the completion handler > of the same request? The commit log did mention the point: Before aborting in-flight requests, all IO queues have been shutdown. which implies that no concurrent normal completion. Thanks, Ming