From owner-freebsd-stable@FreeBSD.ORG  Thu Jan  6 08:10:44 2011
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id BB380106564A;
	Thu,  6 Jan 2011 08:10:44 +0000 (UTC)
	(envelope-from perryh@pluto.rain.com)
Received: from agora.rdrop.com (agora.rdrop.com [IPv6:2607:f678:1010::34])
	by mx1.freebsd.org (Postfix) with ESMTP id 9A4E48FC15;
	Thu,  6 Jan 2011 08:10:44 +0000 (UTC)
Received: from agora.rdrop.com (66@localhost [127.0.0.1])
	by agora.rdrop.com (8.13.1/8.12.7) with ESMTP id p068AbqK035155
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT);
	Thu, 6 Jan 2011 00:10:38 -0800 (PST)
	(envelope-from perryh@pluto.rain.com)
Received: (from uucp@localhost)
	by agora.rdrop.com (8.13.1/8.12.9/Submit) with UUCP id p068Ab0I035154; 
	Thu, 6 Jan 2011 00:10:37 -0800 (PST)
Received: from fbsd61 by pluto.rain.com (4.1/SMI-4.1-pluto-M2060407)
	id AA16440; Thu, 6 Jan 11 00:08:26 PST
Date: Thu, 06 Jan 2011 00:08:04 -0800
From: perryh@pluto.rain.com
To: jhb@freebsd.org
Message-Id: <4d257864.YjgoS235V8eKvUX2%perryh@pluto.rain.com>
References: <1036681015.111502.1294189339355.JavaMail.root@erie.cs.uoguelph.ca>
	<4d244e39.KoPcOoMaWed+H5De%perryh@pluto.rain.com>
	<201101050757.08116.jhb@freebsd.org>
In-Reply-To: <201101050757.08116.jhb@freebsd.org>
User-Agent: nail 11.25 7/29/05
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: marek_sal@wp.pl, freebsd-stable@freebsd.org, jyavenard@gmail.com,
	rmacklem@uoguelph.ca, milu@dat.pl
Subject: Re: NFSv4 - how to set up at FreeBSD 8.1 ?
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 06 Jan 2011 08:10:44 -0000

John Baldwin <jhb@freebsd.org> wrote:

> ... even NFS UDP mounts maintain their own set of "socket" state
> to manage retries and retransmits for UDP RPCs.

Not according to what I remember of the SunOS NFS documentation,
which indicated that the driving force behind using UDP instead of
TCP was to have the server be _completely_ stateless.  (Of course
locking is inherently stateful; they made it very clear that the
locking protocol was considered to be an adjunct rather than part
of the NFS protocol itself.)

It's been quite a few years since I read that, and I didn't get
into the details, but I suppose the handle returned to a client (in
response to a mount or open request) must have contained both a
representation of the inode number and a unique identification of
the filesystem (so that, in the case where server crash recovery
included a newfs and reload from backup, the FS ID would not match
and the client would get a "stale handle" response).  All of the
retry and retransmit burden had to have been managed by the client,
for both reading and writing.