[PATCH] nvmet: fix nvme status code when namespace is disabled

[Chaitanya Kulkarni]

On 4/28/2024 2:25 AM, Sagi Grimberg wrote:
> If the user disabled a nvmet namesapce, it is removed from
> the subsystem namespaces list. When nvmet processes a command
> directed to an nsid that was disabled, it cannot differentiate
> between a nsid that is disabled vs. a non-existent namespace,
> and resorts to return NVME_SC_INVALID_NS with the dnr bit set.
> 
> This translates to a non-retryable status for the host, which
> translates to a user error. We should expect disabled namespaces
> to not cause an I/O error in a multipath environment.
> 
> Address this by searching a configfs item for the namespace nvmet
> failed to find, and if we found one, conclude that the namespace
> is disabled (perhaps temporarily). Return NVME_SC_INTERNAL_PATH_ERROR
> in this case and keep DNR bit cleared.
> 
> Reported-by: Jirong Feng <jirong.feng at easystack.cn>
> Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
> ---
> Jirong Feng, can you please re-run the test as requested and verify
> that the I/O error goes away. If so, please reply with your "Tested-by"
> tag.
> 

FWIW,

Reviewed-by: Chaitanya Kulkarni <kch at nvidia.com>

-ck