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Date: Thu, 28 Mar 2024 17:19:26 -0500
From: Eric Blake <eblake@redhat.com>
To: Stefan Hajnoczi <stefanha@redhat.com>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, 
	Alasdair Kergon <agk@redhat.com>, Mikulas Patocka <mpatocka@redhat.com>, dm-devel@lists.linux.dev, 
	David Teigland <teigland@redhat.com>, Mike Snitzer <snitzer@kernel.org>, Jens Axboe <axboe@kernel.dk>, 
	Christoph Hellwig <hch@lst.de>, Joe Thornber <ejt@redhat.com>
Subject: Re: [RFC 5/9] selftests: block_seek_hole: add dm-zero test
Message-ID: <sr42hsk5rqu5siso6xwjlu5akfegl6glco3ug6pleawszgtfcb@h5pca4b3yqot>
References: <20240328203910.2370087-1-stefanha@redhat.com>
 <20240328203910.2370087-6-stefanha@redhat.com>
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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