File Handles
Question: how does the client tell the server which file or directory the operation applies to?
- Similarly, how does the server return the result of a lookup?
More generally, how to pass a pointer or an object reference as an argument/result of an RPC call?
In NFS, the reference is a file handle or fhandle, a 32-byte token/ticket whose value is determined by the server.
- Includes all information needed to identify the file/object on the server, and get a pointer to it quickly.