Why NFS server does not pass lock requests via VFS lock() op?

[Juan Gomez]

Could anyone remind me of why NFS kernel would not pass byte range lock
requests to the underlying filsystem at the server side?
I think another person at IBM (Brian?) submitted a patch for this but such
patch never got included in the distribution.

I think a patch to pass lock requests to the underlying filesystem does not
affect single node NFS servers and it enables us to
support clustered Linux-based NAS heads over distributed file systems.

Juan