A network file server has storage for storing a file system, and a computer programmed for access to the file system in accordance with a file access protocol and in accordance with a storage access protocol. The computer receives a file access request from a network client for access to a file in the file system in accordance with the network file access protocol. The computer decides whether it should finish the file access using the file access protocol or the client should finish the file access using the storage access protocol. Upon deciding that the client should finish the file access using the storage access protocol, the computer returns to the client metadata of the file including metadata specifying addresses of logical blocks of storage allocated to the file, and then the computer responds to storage access requests from the client by performing read-write access to the file.