[PATCH v2 2/3] nvmet: avoid recursive configfs open for file-backed namespaces

[Christoph Hellwig]

> +	ret = kern_path(ns->device_path, LOOKUP_FOLLOW, &path);
> +	if (ret) {
> +		pr_err("failed to open file %s: (%d)\n",
> +		       ns->device_path, ret);
> +		return ret;
> +	}
> +
> +	if (configfs_path_is_configfs(&path)) {
> +		pr_err("configfs paths cannot back namespace %s\n",
> +		       ns->device_path);
> +		path_put(&path);
> +		return -EINVAL;
> +	}
> +
> +	ns->file = dentry_open(&path, flags, current_cred());

This section of code really should have a helper in configfs.  And should
also be used in other callers like the SCSI target patches you also sent
out.