[Bug Report] nvme-cli commands fails to open head disk node and print error

[Nilay Shroff]

Hi Christoph,

On 4/2/24 20:34, Christoph Hellwig wrote:
> Hi Nilay,
> 
> can you see if this patch makes a different for your weird controller
> with the listed but zero capacity namespaces?
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 3b0498f320e6b9..ad60cf5581a419 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -2089,7 +2089,7 @@ static int nvme_update_ns_info_block(struct nvme_ns *ns,
>  	if (id->ncap == 0) {
>  		/* namespace not allocated or attached */
>  		info->is_removed = true;
> -		ret = -ENODEV;
> +		ret = -ENXIO;
>  		goto out;
>  	}
>  	lbaf = nvme_lbaf_index(id->flbas);
> 
I have just tested the above patch on my controller which has zero 
capacity namespaces. The patch works as expected and I don't encounter
any errors while using nvme-cli commands. Please note that I am using 
here the old version of nvme-cli (nvme version 2.6 / libnvme version 1.6).

Furthermore, with this patch, I no longer find any hidden disk nodes 
(i.e. nvmeXcYnZ or nvmeXnY) created for namespaces with zero capacity 
under /sys/block. So the behavior is similar to that of kernel v6.8.

IMO, we should upstream this patch.

Thanks,
--Nilay