Re: [PATCH v9 5/8] fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero

[Christoph Hellwig]

On Wed, Sep 15, 2021 at 06:44:58PM +0800, Shiyang Ruan wrote:
> +	rc = dax_direct_access(iomap->dax_dev, pgoff, 1, &kaddr, NULL);
> +	if (rc < 0)
> +		goto out;
> +	memset(kaddr + offset, 0, size);
> +	if (srcmap->addr != IOMAP_HOLE && srcmap->addr != iomap->addr) {

Should we also check that ->dax_dev for iomap and srcmap are different
first to deal with case of file system with multiple devices?

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@xxxxxx>