[PATCH] nvme-fabrics: show well known discovery name

[Hannes Reinecke]

On 2/21/23 17:51, Daniel Wagner wrote:
> The kernel always logs the unique subsystem name for a discovery
> controller, even in the case user space asked for the well known.
> 
> This has lead to confusion as the logs of nvme-cli and the kernel
> logs didn't match.
> 
> First, nvme-cli connects to the well known discovery controller to
> figure out if it supports TP8013. If so then nvme-cli disconnects and
> connects to the unique discovery controller. Currently, the kernel show
> that user space connected twice to the unique one.
> 
> To avoid further confusion, show the well known discovery controller if
> user space asked for it:
> 
>    $ nvme connect-all -v -t tcp -a 192.168.0.1
>    nvme0: nqn.2014-08.org.nvmexpress.discovery connected
>    nvme0: nqn.2014-08.org.nvmexpress.discovery disconnected
>    nvme0: nqn.discovery connected
> 
>    kernel log:
>    nvme nvme0: new ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery", addr 192.168.0.1:8009
>    nvme nvme0: Removing ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery"
>    nvme nvme0: new ctrl: NQN "nqn.discovery", addr 192.168.0.1:8009
> 
> Fixes: e5ea42faa773 ("nvme: display correct subsystem NQN")
> Cc: Hannes Reinecke <hare at suse.de>
> Cc: Chaitanya Kulkarni <kch at nvidia.com>
> Signed-off-by: Daniel Wagner <dwagner at suse.de>
> ---
>   drivers/nvme/host/fabrics.h | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h
> index a6e22116e139..dcac3df8a5f7 100644
> --- a/drivers/nvme/host/fabrics.h
> +++ b/drivers/nvme/host/fabrics.h
> @@ -189,7 +189,8 @@ nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
>   
>   static inline char *nvmf_ctrl_subsysnqn(struct nvme_ctrl *ctrl)
>   {
> -	if (!ctrl->subsys)
> +	if (!ctrl->subsys ||
> +	    !strcmp(ctrl->opts->subsysnqn, NVME_DISC_SUBSYS_NAME))
>   		return ctrl->opts->subsysnqn;
>   	return ctrl->subsys->subnqn;
>   }
Reviewed-by: Hannes Reinecke <hare at suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare at suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman