Re: Fwd: NFS 5-minute hangs upon S3 resume using 2.6.27 client

[Michel Lespinasse <walken-Y93EPB1FQwg@public.gmane.org>]

On Fri, Oct 24, 2008 at 08:29:28AM -0400, Trond Myklebust wrote:
> On Thu, 2008-10-23 at 23:57 -0700, Michel Lespinasse wrote:
> > I applied this on top of the previous patch and it worked - but now I'm
> > not sure if you wanted to test this as an independant patch ???
> It was meant to be applied incrementally on top of the other.

OK. Worked fine, then. Thanks again !

> > Can I propose a patch too ? mine looks quite similar to your second patch,
> > but with the reestablish_timeout logic hopefully simplified...
> 
> This would cause a different regression. The current code is there in
> order to ensure that we apply that exponential backoff if and only if
> the _server_ closes the TCP connection since that would usually indicate
> that it is trying to deal with a resource congestion issue. We don't
> need to back off if we were the ones closing the socket.

So the idea is to backoff if the connection is closed by a server FIN but
retry right away if it's closed by a RST ?
I did not realize that, but this makes sense too...

> The issue of UDP exponential backoff is moot: the UDP code doesn't use
> xs_connect() at all.

Hrmmm ? I see the following down the file:
static struct rpc_xprt_ops xs_udp_ops = {
...
        .connect                = xs_connect,
...
}

I'm not sure if/when the callback is actually called in the UDP case,
but it's definitely being set up that way.

-- 
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.