Re: [libvirt PATCH v2 23/24] qemu_snapshot: add checks for external snapshot deletion

With the introduction of external snapshot revert support we need to error out in some cases when trying to delete some snapshots. If users reverts to non-leaf snapshots and would try to delete it after the revert is done it would not work currently as this operation would require using block-stream which is not implemented for now as in this case the snapshot has two children so the disk files have multiple overlays. Similarly if user reverts to non-leaf snapshot and would try to delete snapshot that is non-leaf but not in currently active snapshot chain we would still need to use block-commit operation. The issue here is that in order to do that we would have to start new qemu process with different domain definition than what is currently used by the domain. If the current domain would be running it would complicate things even more so this operation is not yet supported. If user creates new snapshot after reverting to non-leaf snapshot it creates a new branch. Deleting snapshot with multiple children will require block-stream which is not implemented for now. Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; --- src/qemu/qemu_snapshot.c | 21 +++++++++++++++++++++