Re: [PATCH 08/10] lockd: struct nlm_reboot should contain a full socket address

["J. Bruce Fields" <bfields@fieldses.org>]

On Wed, Oct 01, 2008 at 04:51:56PM -0400, bfields wrote:
> On Wed, Oct 01, 2008 at 04:42:51PM -0400, Chuck Lever wrote:
> > On Oct 1, 2008, at Oct 1, 2008, 4:08 PM, J. Bruce Fields wrote:
> >> On Wed, Oct 01, 2008 at 03:40:05PM -0400, Chuck Lever wrote:
> >>> Right.  I couldn't think of something simpler.
> >>>
> >>> rpc.statd has to continue to work with legacy kernels where the  
> >>> first 4
> >>> bytes of the opaque are a 32-bit sin_addr field and the following 12
> >>> bytes are zero.
> >>
> >> Wait a minute, there's something not right there: rpc.statd shouldn't
> >> interpret the contents of the opaque field at all, should it?
> >
> > Yes, our rpc.statd and lockd should agree on the contents and  
> > interpretation of the opaque field.  The field is opaque because it's  
> > internal content is not defined by a standard.  It's a cookie, just like 
> > a file handle.
> >
> > I would certainly *prefer* the use of an entirely arbitrary cookie, but 
> > that's not the way Linux happens to work today.
> 
> I'm pretty certain it does--at least on the rpc.statd size.  (Any
> evidence to the contrary.)  Sure, it means something to the kernel, but

(Err, I think that parenthetical remark was meant to be a question.
Apologies.)

> that's just for the kernel's convenience.  We can do whatever we want in
> the kernel.
> 
> --b.