[Devel] [PATCH 2/6] nfsd: swap fs root in NFSd kthreads

[J. Bruce Fields]

On Tue, Dec 11, 2012 at 10:20:36AM -0500, J. Bruce Fields wrote:
> On Tue, Dec 11, 2012 at 07:07:00PM +0400, Stanislav Kinsbursky wrote:
> > I don't really understand, how  mountd's root can be wrong. I.e.
> > its' always right as I see it. NFSd kthreads have to swap/use
> > relative path/whatever to communicate with proper mountd.
> > Or I'm missing something?
> 
> Ugh, I see the problem: I thought svc_export_request was called at the
> time mountd does the read, but instead its done at the time nfsd does
> the upcall.
> 
> I suspect that's wrong, and we really want this done in the context of
> the mountd process when it does the read call.  If d_path is called
> there then we have no problem.

Right, so I'd be happier if we could modify sunrpc_cache_pipe_upcall to
skip calling cache_request and instead delay that until cache_read().  I
think that should be possible.

--b.