[AFS3-std] Extending AFSVolDump

[Jeffrey Hutzelman]

I want to extend AFSVolDump to add a flag indicating that incremental dumps 
should not include complete copies of directories that have not change. 
Dumps of this form are already generated by AFSVolForward, for the 
incremental dumps used to clean up at the end of a move or release.  I want 
to make it possible to do the same thing when you have a system which dumps 
a volume with AFSVolDump, processes the dump, and then restores it to some 
server with AFSVolRestore.

Of course, there are safety considerations, in that an incremental dump 
which does not contain a complete directory structure may result in an 
inconsistent volume when restored over the wrong existing volume.  However, 
I would not expect the new mode of operation to be the default, and I feel 
that making it available is worth the risk.


Of course, by "extending" AFSVolDump, I actually mean to define a new, 
similar RPC.  My intent would be to add a new flags argument (and create a 
registry of flags), with a flag requesting dumps using this feature.


Comments?

-- Jeff