[dm-devel] [RESEND PATCH] nvme: explicitly use normal NVMe error handling when appropriate

[Christoph Hellwig]

On Thu, Aug 13, 2020 at 10:48:11AM -0400, Mike Snitzer wrote:
> Commit 764e9332098c0 ("nvme-multipath: do not reset on unknown
> status"), among other things, fixed NVME_SC_CMD_INTERRUPTED error
> handling by changing multipathing's nvme_failover_req() to short-circuit
> path failover and then fallback to NVMe's normal error handling (which
> takes care of NVME_SC_CMD_INTERRUPTED).
> 
> This detour through native NVMe multipathing code is unwelcome because
> it prevents NVMe core from handling NVME_SC_CMD_INTERRUPTED independent
> of any multipathing concerns.
> 
> Introduce nvme_status_needs_local_error_handling() to prioritize
> non-failover retry, when appropriate, in terms of normal NVMe error
> handling.  nvme_status_needs_local_error_handling() will naturely evolve
> to include handling of any other errors that normal error handling must
> be used for.
> 
> nvme_failover_req()'s ability to fallback to normal NVMe error handling
> has been preserved because it may be useful for future NVME_SC that
> nvme_status_needs_local_error_handling() hasn't been trained for yet.
> 
> Signed-off-by: Mike Snitzer <snitzer at redhat.com>

I don't see how this would change anything.  nvme_failover_req simply
retuns false for NVME_SC_CMD_INTERRUPTED, so your change is a no-op.