[PATCH 2/2] nvme-multipath: do not fall back to __nvme_find_path() for non-optimized paths

[Sagi Grimberg]

On 7/27/20 9:08 AM, Hannes Reinecke wrote:
> When nvme_round_robin_path() finds a valid namespace we should be using it;
> falling back to __nvme_find_path() for non-optimized paths will cause the
> result from nvme_round_robin_path() to be ignored for non-optimized paths.
> 
> Signed-off-by: Martin Wilck <mwilck at suse.com>
> Signed-off-by: Hannes Reinecke <hare at suse.de>
> ---
>   drivers/nvme/host/multipath.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
> index fe8f7f123fac..97d3c19b5684 100644
> --- a/drivers/nvme/host/multipath.c
> +++ b/drivers/nvme/host/multipath.c
> @@ -272,8 +272,11 @@ inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head)
>   	struct nvme_ns *ns;
>   
>   	ns = srcu_dereference(head->current_path[node], &head->srcu);
> -	if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_RR && ns)
> +	if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_RR && ns) {
>   		ns = nvme_round_robin_path(head, node, ns);
> +		if (ns)
> +			return ns;
> +	}
>   	if (unlikely(!ns || !nvme_path_is_optimized(ns)))
>   		ns = __nvme_find_path(head, node);

Maybe instead of the early return put the following condition on else?