NFS 4: mount submounts automatically

[dpirate]

When a directory that is exported with NFS 4 from Linux has one or more file systems that are mounted under it, the Haiku NFS 4 client only mounts the root directory and not the underlying file systems. The directories where the underlying file systems are mounted are hidden as well. The underlying file systems can however be mounted separately in Haiku. In Linux, however mounting the root filesystem automatically mounts the underlying filesystems. It would be nice if Haiku behaved this way as well.

This is an example of a Linux /etc/exportfs entry with submounts:

/my/exported/directory 192.168.1.0/24(ro,fsid=1,crossmnt,subtree_check)