Virtual File System

[Caveh Jalali]

In article <2751 at brazos.Rice.edu> Robert.Smart at ditmela.oz.au (Robert Smart) writes:
>X-Sun-Spots-Digest: Volume 8, Issue 183, message 12 of 13
>
>The SunOS documentation makes brief mention of a Virtual File System
>layer. Is there any available information on how to create your own VFS?

If I understand the question correctly, you want to implement your own
file system.  In this case you don't want your own VFS, you want your own
FS -- this can be implemented "using" NFS.

The simplest example of such a beast is automount.  All automount does is
to mount itself (a NFS daemon, but user process) on /home.  now, all
subsequent accesses to /home are routed to this process using a set of
RPCs (the standard ones defined by NFS).  You now have full control over
such operations as directory lookups, file reads, etc...  everything you
need to implement a file system.  In the case of automount, only symlinks
and directory reads are implemented.  It's a very clever way to avoid
having to do "anything".  I had a good laugh when I figured this one out!

here are some areas which will set you on the right track (sun manuals):
1. RPC & rpcgen
2. NFS protocol def'n (RPC)
3. mount - in particular mounting a process (NFS)