Re: [PATCH v2 03/10] nvme-multipath: add error handling support for add_disk()

[Keith Busch]

On Mon, Sep 27, 2021 at 03:00:32PM -0700, Luis Chamberlain wrote:
> +	/*
> +	 * test_and_set_bit() is used because it is protecting against two nvme
> +	 * paths simultaneously calling device_add_disk() on the same namespace
> +	 * head.
> +	 */
>  	if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) {
> -		device_add_disk(&head->subsys->dev, head->disk,
> -				nvme_ns_id_attr_groups);
> +		rc = device_add_disk(&head->subsys->dev, head->disk,
> +				     nvme_ns_id_attr_groups);
> +		if (rc)
> +			return;
> +		set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags);

No need to set_bit() here since the test_and_set_bit() already took care
of that.