[PATCH] Convert Samba to OFD locking - version 2

[Jeremy Allison]

On Mon, May 23, 2016 at 10:26:42AM -0400, Jeff Layton wrote:
> 
> AFAICT, this patch makes no material difference in testing.
> 
> The client first compares the incoming lock request vs. the local lock
> database. If there is already a conflicting lock set on the file, it's
> rejected there before the lock request ever goes to the server. I guess
> this makes sense from a performance standpoint -- no need to go out
> over the network if we already know there's a conflicting lock.
> 
> This patch does seem more correct to me than sending the pid, given how
> samba uses that field. But, I think we already have working OFD
> semantics anyway, as long as the client's kernel supports them properly
> for local filesystems.

I still think this is worth doing, as otherwise the lock
requests sent remote will end up with the same lock context
over SMB1, which complicates the server's life :-).