[PATCH 6/6] nvme: return -ETIMEDOUT in nvme_submit_sync_cmd()

[Keith Busch]

On Thu, Feb 25, 2021 at 11:55:27AM +0100, Hannes Reinecke wrote:
> When a command times out we should be returning -ETIMEDOUT in
> nvme_submit_sync_cmd(), and not requiring the caller to guess whether
> a specific NVMe status should be interpreted as a timeout.

This driver has been using -EINTR for this condition since the
beginning, though. Is there a reason I'm not seeing why these use cases
can't use the existing command cancelled flag?
 
> Signed-off-by: Hannes Reinecke <hare at suse.de>
> ---
>  drivers/nvme/host/core.c | 2 ++
>  drivers/nvme/host/fc.c   | 1 +
>  drivers/nvme/host/nvme.h | 1 +
>  drivers/nvme/host/rdma.c | 1 +
>  drivers/nvme/host/tcp.c  | 1 +
>  5 files changed, 6 insertions(+)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 624531a6b7c6..5c1ec3bfb9d3 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -1004,6 +1004,8 @@ int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
>  		*result = nvme_req(req)->result;
>  	if (nvme_req(req)->flags & NVME_REQ_CANCELLED)
>  		ret = -EINTR;
> +	else if (nvme_req(req)->flags & NVME_REQ_TIMEOUT)
> +		ret = -ETIMEDOUT;
>  	else
>  		ret = nvme_req(req)->status;
>   out:
> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> index 86395b66310d..bcc086fcbe61 100644
> --- a/drivers/nvme/host/fc.c
> +++ b/drivers/nvme/host/fc.c
> @@ -2551,6 +2551,7 @@ nvme_fc_timeout(struct request *rq, bool reserved)
>  		"x%08x/x%08x\n",
>  		ctrl->cnum, op->queue->qnum, sqe->common.opcode,
>  		sqe->connect.fctype, sqe->common.cdw10, sqe->common.cdw11);
> +	op->nreq.flags |= NVME_REQ_TIMEOUT;
>  	if (__nvme_fc_abort_op(ctrl, op))
>  		nvme_fc_error_recovery(ctrl, "io timeout abort failed");
>  
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index 07b34175c6ce..02aa4ba665c0 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -173,6 +173,7 @@ struct nvme_request {
>  enum {
>  	NVME_REQ_CANCELLED		= (1 << 0),
>  	NVME_REQ_USERCMD		= (1 << 1),
> +	NVME_REQ_TIMEOUT		= (1 << 2),
>  };
>  
>  static inline struct nvme_request *nvme_req(struct request *req)
> diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
> index 53ac4d7442ba..99ad2e10b295 100644
> --- a/drivers/nvme/host/rdma.c
> +++ b/drivers/nvme/host/rdma.c
> @@ -1990,6 +1990,7 @@ static void nvme_rdma_complete_timed_out(struct request *rq)
>  	nvme_rdma_stop_queue(queue);
>  	if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
>  		nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
> +		nvme_req(rq)->flags |= NVME_REQ_TIMEOUT;
>  		blk_mq_complete_request(rq);
>  	}
>  }
> diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
> index 69f59d2c5799..64aab742c84d 100644
> --- a/drivers/nvme/host/tcp.c
> +++ b/drivers/nvme/host/tcp.c
> @@ -2189,6 +2189,7 @@ static void nvme_tcp_complete_timed_out(struct request *rq)
>  	nvme_tcp_stop_queue(ctrl, nvme_tcp_queue_id(req->queue));
>  	if (blk_mq_request_started(rq) && !blk_mq_request_completed(rq)) {
>  		nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD;
> +		nvme_req(rq)->flags |= NVME_REQ_TIMEOUT;
>  		blk_mq_complete_request(rq);
>  	}
>  }
> -- 
> 2.29.2
> 
> 
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