[PATCH 1/6] nvme: simplify error logic in nvme_validate_ns()

[Keith Busch]

On Thu, Feb 25, 2021 at 11:55:22AM +0100, Hannes Reinecke wrote:
> We only should remove namespaces when we get fatal error back from
> the device or when the namespace IDs have changed.
> So instead of painfully masking out error numbers which might indicate
> that the error should be ignored we could use an NVME status code
> to indicated when the namespace should be removed.
> That simplifies the final logic and makes it less error-prone.

I think this looks good to me. The timeout condition should retain
discovered namespaces since the controller is going to be restarted.

Reviewed-by: Keith Busch <kbusch at kernel.org>
 
> Signed-off-by: Hannes Reinecke <hare at suse.de>
> ---
>  drivers/nvme/host/core.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index d77f3f26d8d3..13ed7d3fbbb3 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -4036,7 +4036,7 @@ static void nvme_ns_remove_by_nsid(struct nvme_ctrl *ctrl, u32 nsid)
>  static void nvme_validate_ns(struct nvme_ns *ns, struct nvme_ns_ids *ids)
>  {
>  	struct nvme_id_ns *id;
> -	int ret = -ENODEV;
> +	int ret = NVME_SC_INVALID_NS | NVME_SC_DNR;
>  
>  	if (test_bit(NVME_NS_DEAD, &ns->flags))
>  		goto out;
> @@ -4045,7 +4045,7 @@ static void nvme_validate_ns(struct nvme_ns *ns, struct nvme_ns_ids *ids)
>  	if (ret)
>  		goto out;
>  
> -	ret = -ENODEV;
> +	ret = NVME_SC_INVALID_NS | NVME_SC_DNR;
>  	if (!nvme_ns_ids_equal(&ns->head->ids, ids)) {
>  		dev_err(ns->ctrl->device,
>  			"identifiers changed for nsid %d\n", ns->head->ns_id);
> @@ -4063,7 +4063,7 @@ static void nvme_validate_ns(struct nvme_ns *ns, struct nvme_ns_ids *ids)
>  	 *
>  	 * TODO: we should probably schedule a delayed retry here.
>  	 */
> -	if (ret && ret != -ENOMEM && !(ret > 0 && !(ret & NVME_SC_DNR)))
> +	if (ret > 0 && (ret & NVME_SC_DNR))
>  		nvme_ns_remove(ns);
>  }
>  
> -- 
> 2.29.2