Re: [Qemu-devel] [PATCH v2 3/3] iotests: Add test for rebase without input base

[Kevin Wolf <kwolf@redhat.com>]

Am 08.05.2019 um 16:01 hat Max Reitz geschrieben:
> This patch adds a test for rebasing an image that currently does not
> have a backing file.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  tests/qemu-iotests/024     | 70 ++++++++++++++++++++++++++++++++++++++
>  tests/qemu-iotests/024.out | 37 ++++++++++++++++++++
>  2 files changed, 107 insertions(+)
> 
> diff --git a/tests/qemu-iotests/024 b/tests/qemu-iotests/024
> index 23298c6f59..baf8ec9f28 100755
> --- a/tests/qemu-iotests/024
> +++ b/tests/qemu-iotests/024
> @@ -198,6 +198,76 @@ echo
>  # $BASE_OLD and $BASE_NEW)
>  $QEMU_IMG map "$OVERLAY" | _filter_qemu_img_map
>  
> +echo
> +echo "=== Test rebase without input base ==="
> +echo
> +
> +# Cluster allocations to be tested:
> +#
> +# Backing (new) 11 -- 11 -- 11 --
> +# COW image     22 22 11 11 -- --
> +#
> +# Expected result:
> +#
> +# COW image     22 22 11 11 00 --
> +#
> +# (Cluster 2 might be "--" after the rebase, too, but rebase just
> +#  compares the new backing file to the old one and disregards the
> +#  overlay.  Therefore, it will never discard overlay clusters.)

Is there a reason not to do that, though? I haven't tried it, but
shouldn't it be as easy as reading from blk instead of blk_old_backing?

Matter for another patch, though.

Kevin