Re: [PATCH v5 2/7] dax: introduce dax device flag DAXDEV_RECOVERY

[Christoph Hellwig]

On Fri, Jan 28, 2022 at 02:31:45PM -0700, Jane Chu wrote:
> +int dax_prep_recovery(struct dax_device *dax_dev, void **kaddr)
> +{
> +	if (dax_recovery_capable(dax_dev)) {
> +		set_bit(DAXDEV_RECOVERY, (unsigned long *)kaddr);
> +		return 0;
> +	}
> +	return -EINVAL;

Setting a random bit on a passed in memory address looks a little
dangerous to me.

Also I'd return early for the EINVAL case to make the flow a little
more clear.