Re: [PATCH v2 9/9] exfat: add support for SEEK_HOLE and SEEK_DATA in llseek

[Christoph Hellwig]

>  	} else {
> +		/*
> +		 * valid_size is tracked in byte granularity and
> +		 * marks the exact boundary between valid data and
> +		 * holes (or unwritten space).
> +		 *
> +		 * When IOMAP_REPORT is set (used by lseek(SEEK_HOLE)
> +		 * and SEEK_DATA), we return IOMAP_HOLE. This allows
> +		 * iomap_seek_hole_iter() to directly return the
> +		 * precise byte position.
> +		 *
> +		 * For normal I/O paths (without IOMAP_REPORT) we
> +		 * return IOMAP_UNWRITTEN so the write path can
> +		 * distinguish it from a real hole.
> +		 */

Ahhm this mostly has what I asked for earlier.  But maybe also
describe the IOMAP_F_ZERO_TAIL handling a bit above?

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@xxxxxx>