On 04/13/2017 03:34 PM, Max Reitz wrote: > It does not make much sense to use a backing image for the target when > you concatenate multiple images (because then there is no correspondence > between the source images' backing files and the target's); but it was > still possible to give one by using -o backing_file=X instead of -B X. > > Fix this by moving the check. > > (Also, change the error message because -B is not the only way to > specify the backing file, evidently.) For that matter, 'create -B' is intentionally? undocumented in the qemu-img --help and man page. (Personally, I don't know why we don't want it documented - is it because it it not a universal option because not all formats support backing files?) > > Cc: qemu-stable > Signed-off-by: Max Reitz > --- > qemu-img.c | 14 +++++++------- > tests/qemu-iotests/122.out | 4 ++-- > 2 files changed, 9 insertions(+), 9 deletions(-) > Reviewed-by: Eric Blake Having a backing file for the destination may still make sense for some convoluted workflow, but you can get that with a followup qemu-img rebase. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org