[PATCH 4/4] nvme: check that EUI/GUID/UUID are globally unique

[Christoph Hellwig]

On Mon, Jun 06, 2022 at 08:35:39PM +0000, Alan Adamson wrote:
> nvme driver changes:

Thanks! 

>  
>  	ret = nvme_global_check_duplicate_ids(ctrl->subsys, ids);
>  	if (ret) {
> -		dev_err(ctrl->device,
> -			"globally duplicate IDs for nsid %d\n", nsid);
> -		return ret;
> +		if (ctrl->opts && ctrl->opts->clear_ids) {
> +			uuid_copy(&ids->uuid, &uuid_null);
> +			memset(&ids->nguid, 0, sizeof(ids->nguid));
> +			memset(&ids->eui64, 0, sizeof(ids->eui64));
> +		} else {
> +			dev_err(ctrl->device,
> +				"globally duplicate IDs for nsid %d\n", nsid);
> +			return ret;
> +		}

I don't think this is the right place to clear the reported IDs.
The proper place would be in the target code in
nvmet_passthru_override_id_ns and a new
nvmet_passthru_override_id_ns_desc like it.  Otherwise we only catch
the kernel driver uses and not other users of the IDs.

> @@ -593,6 +595,8 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
>  			}
>  			kfree(opts->transport);
>  			opts->transport = p;
> +			if (!strcmp(p, "loop"))
> +				opts->clear_ids = true;

And maybe add a comment here.