A disk of type 'volume' is stored as
<source pool='pool_name' volume='volume_name'/>
and its real location is inside the 'volume_name', as 'pool_name': in
this case, query libvirt for the actual path of the specified volume in
the specified pool.
Adjust the code so that:
- for_each_disk gets the virConnectPtr, needed to do operations with
libvirt
- when extracting the disk filename depending on the type, the code
snippet doing it can directly set 'filename', without setting an XPath
result variable
Only file-based volumes are supported for now; more types can be added
(with proper testing) later on.
4c3968f262