When the NFSv3 access method is called and there is no correspoding

When the NFSv3 access method is called and there is no correspoding
mount point for the path we requested, we need to return ESTALE so
that the kernel will then perform an NFSv3 lookup and the mount point
will be re-mounted.

If there is no map entry to mount, the NFSv3 lookup method will
return the failure.

(Ian Kent)