NOTE: cnid_add calls this before adding a new CNID.
4) when you delete a file or directory, you need to call
cnid_delete with the CNID for that file/directory.
- 5) if you're just moving a CNID, call cnid_move with the CNID
- and the new dev/ino,did/name pairs.
- 6) call cnid_close when closing the volume.
+ 5) call cnid_close when closing the volume.