Re: [RFC 5/9] selftests: block_seek_hole: add dm-zero test

Eric Blake
2024-03-28T22:19:39Z

On Thu, Mar 28, 2024 at 04:39:06PM -0400, Stefan Hajnoczi wrote:
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> .../selftests/block_seek_hole/Makefile | 2 +-
> .../testing/selftests/block_seek_hole/config | 2 ++
> .../selftests/block_seek_hole/dm_zero.sh | 31 +++++++++++++++++++
> 3 files changed, 34 insertions(+), 1 deletion(-)
> create mode 100755 tools/testing/selftests/block_seek_hole/dm_zero.sh
>

> +++ b/tools/testing/selftests/block_seek_hole/dm_zero.sh
> @@ -0,0 +1,31 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +# dm_zero.sh
> +#
> +# Test that dm-zero reports data because it does not have a custom
> +# SEEK_HOLE/SEEK_DATA implementation.

Why not? Wouldn't it make more sense to have dm-zero report the
entire device as a hole (that is, an in-range SEEK_HOLE always returns
the same offset, while an in-range SEEK_DATA returns the device size)?

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.
Virtualization: qemu.org | libguestfs.org