[PATCH V3 3/3] nvme: retry commands based on ACRE flag

[Chao Leng]

Reviewed-by: Chao Leng <lengchao at huawei.com>

On 2021/1/14 21:31, Minwoo Im wrote:
> Allow nvme_decide_disposition() to retry commands with error by checking
> Advanced Command Retry Enable (ACRE) flag of controller first than
> REQ_FAILFAST_* cmd_flags.  But, we just can't allow all command failures
> to be retried due to reasons like connecting may take too long due to
> the retries.  This patch only allows non-host path error commands to be
> retried.
> 
> Cc: Chao Leng <lengchao at huawei.com>
> Cc: Sagi Grimberg <sagi at grimberg.me>
> Cc: Keith Busch <kbusch at kernel.org>
> Signed-off-by: Minwoo Im <minwoo.im.dev at gmail.com>
> ---
>   drivers/nvme/host/core.c | 10 ++++++++--
>   1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index a286e3422c61..e4f7c49c2f39 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -303,8 +303,7 @@ static inline enum nvme_disposition nvme_decide_disposition(struct request *req)
>   	if (likely(nvme_req(req)->status == 0))
>   		return COMPLETE;
>   
> -	if (blk_noretry_request(req) ||
> -	    (nvme_req(req)->status & NVME_SC_DNR) ||
> +	if ((nvme_req(req)->status & NVME_SC_DNR) ||
>   	    nvme_req(req)->retries >= nvme_max_retries)
>   		return COMPLETE;
>   
> @@ -317,6 +316,13 @@ static inline enum nvme_disposition nvme_decide_disposition(struct request *req)
>   			return COMPLETE;
>   	}
>   
> +	if (nvme_req(req)->ctrl->acre &&
> +	    !nvme_is_path_error(nvme_req(req)->status) &&
> +	    !blk_queue_dying(req->q))
> +		return RETRY;
> +	else if (blk_noretry_request(req))
> +		return COMPLETE;
> +
>   	return RETRY;
>   }
>   
>