oplocks breaks when Tree is forcefully disconnected

[Kashif Shaikh]

Hello Samba developers,

I've been digging through the code, and one thing I've noticed is that 
Samba doesn't do a local oplock_break() when a tree is forcefully 
disconnected either through exit_server() or msg_force_tdis().

I would assume this is quite important, as it would give clients a 
chance to flush their modified buffers before Samba exits or
decides to close the Tree.

A nice place to put a request_oplock_break() would be in 
close_normal_file() /w normal_close flag set to FALSE.  Though I don't 
know the implications of such an action(i.e. I don't want to hurt 
performance or cause unwanted side effects everytime a file is closed).

So what do you guys think?

Regards,

Kashif Shaikh