Test an allocating write to a parallels image that has a backing node.
Before HEAD^, doing so used to give me a failed assertion (when the
backing node contains only `42` bytes; the results varies with the value
chosen, for `0` bytes, for example, all I get is EIO).
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20220714132801.72464-3-hreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>