On 06/16/2017 08:58 AM, Max Reitz wrote:
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
> In order to pass, this depends on "fix: avoid an infinite loop or a
> dangling pointer problem in img_commit"
> (http://lists.nongnu.org/archive/html/qemu-block/2017-06/msg00443.html)

Looks like that is now 4172a003

> and on the "block: Don't compare strings in bdrv_reopen_prepare()"
> series
> (http://lists.nongnu.org/archive/html/qemu-block/2017-06/msg00424.html).

Still pending.

> ---
>  tests/qemu-iotests/020     | 27 +++++++++++++++++++++++++++
>  tests/qemu-iotests/020.out | 17 +++++++++++++++++
>  2 files changed, 44 insertions(+)
> 
> diff --git a/tests/qemu-iotests/020 b/tests/qemu-iotests/020
> index 7a11110..83d5ef0 100755
> --- a/tests/qemu-iotests/020
> +++ b/tests/qemu-iotests/020
> @@ -110,6 +110,33 @@ for offset in $TEST_OFFSETS; do
>      io_zero readv $(( offset + 64 * 1024 + 65536 * 4 )) 65536 65536 1
>  done
>  _check_test_img
> +_cleanup
> +TEST_IMG=$TEST_IMG_SAVE
> +
> +echo
> +echo 'Testing failing commit'
> +echo
> +
> +# Create an image with a null backing file to which committing will fail (with
> +# ENOSPC so we can distinguish the result from some generic EIO which may be
> +# generated anywhere in the block layer)
> +_make_test_img -b "json:{'driver': 'raw',
> +                         'file': {
> +                             'driver': 'blkdebug',
> +                             'inject-error': [{
> +                                 'event': 'write_aio',
> +                                 'errno': 28,

Still nasty that we encoded an errno value rather than using a
stringified enum, but that's not your problem.

> +                                 'once': true
> +                             }],
> +                             'image': {
> +                                 'driver': 'null-co'
> +                             }}}"

The comment does wonders for explaining how it all works!

> +
> +# Just write anything so comitting will not be a no-op

s/comitting/committing/

With the typo fix,
Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org