Re: [PATCH v2 2/4] blk-integrity: convert to struct device_attribute

[Christoph Hellwig]

> +		container_of(attr, struct device_attribute, attr);
>  	ssize_t ret = 0;
>  
> +	if (dev_attr->store)
> +		ret = dev_attr->store(dev, dev_attr, page, count);
>  
>  	return ret;

This can be simplified to:

	if (!rev_attr->store)
		return 0;
	return dev_attr->store(dev, dev_attr, page, count);

(I'm still confused why 0 is the right return value here, but that's not
 new in your patch, so better don't rock that boat).

> +static ssize_t format_show(struct device *dev, struct device_attribute *attr, char *page)

Please avoid the overly long line here. an in the other methods.