[ovirt-devel] do we even handle volume metadata in the engine?

Hi, It seems I was able to get my setup working for NFS storage, thanks for your advices! Now I'm afraid I am stuck again: what I need to do is to add validation for volume metadata to a certain command (to be exact, that VOLTYPE is LEAF). But I can't find examples of us dealing with this data in the engine part at all. I understand this is in the end executed by VDSM, but nevertheless - in what format are we even reading and writing volume metadata? Even class/method name would be helpful. Thanks, Fedor