Ceph » rbd

copyup helper to perform a copyup from parent to child. will be used by both the rbd command-line copyup command, and librbd when a child object is missing. will read the parent object(s), and call the cls_rbd copyup method on the child object(s) to keep things atomic/safe. should operate on an arbitrary range.

should take an optional progress indicator thinger for the rbd tool's benefit.