Christoph,
> For block devices the target code implements UNMAP as calls to
> blkdev_issue_discard, which does not guarantee zeroing just because
> Write Zeroes is supported.
>
> Note that this does not affect the file backed path which uses
> fallocate to punch holes.
>
> Fixes: 2237498f0b5c ("target/iblock: Convert WRITE_SAME to blkdev_issue_zeroout")
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
--
Martin K. Petersen Oracle Linux Engineering
