From owner-freebsd-current@FreeBSD.ORG  Tue May 13 00:05:22 2003
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id DCBA937B401; Tue, 13 May 2003 00:05:22 -0700 (PDT)
Received: from mail.allcaps.org (allcaps.org [216.240.173.16])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id 6287443FAF; Tue, 13 May 2003 00:05:22 -0700 (PDT)
	(envelope-from bsder@allcaps.org)
Received: from mail.allcaps.org (localhost [127.0.0.1])
	by mail.allcaps.org (Postfix) with ESMTP
	id 885D092FAF; Tue, 13 May 2003 03:08:20 -0400 (EDT)
Received: from localhost (bsder@localhost)h4D78KFt031198;
	Tue, 13 May 2003 00:08:20 -0700
X-Authentication-Warning: mail.allcaps.org: bsder owned process doing -bs
Date: Tue, 13 May 2003 00:08:20 -0700 (PDT)
From: "Andrew P. Lentvorski, Jr." <bsder@allcaps.org>
To: Robert Watson <rwatson@FreeBSD.org>
In-Reply-To: <Pine.NEB.3.96L.1030512223339.4858G-100000@fledge.watson.org>
Message-ID: <Pine.LNX.4.44.0305122350240.31102-100000@mail.allcaps.org>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
cc: Don Lewis <truckman@FreeBSD.org>
cc: alfred@FreeBSD.org
cc: current@FreeBSD.org
Subject: Re: rpc.lockd spinning; much breakage
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 13 May 2003 07:05:23 -0000

On Mon, 12 May 2003, Robert Watson wrote:

> (3) Sometimes rpc.lockd on 5.x acting as a server gets really confused
>     when you mix local and remote locks.

Yes, don't do that. ;)

One problem is that FreeBSD doesn't allocate enough fields in its local
lock structure to distinguish external identifiers in the locks (all locks
look like they are owned by the rpc.lockd user).  Consequently, rpc.lockd
has to maintain its own state as to who has what locks.

I believe there were also some issues with atomicity in POSIX partial file 
locking on FreeBSD that have since been fixed.

Consequently, I punted when I wrote the rpc.lockd code to support POSIX
partial file locking.  The server rpc.lockd locks the *entire file* when
it gets an NFS request to lock any portion of it.  In addition, it will
return an immediate fail if the kernel has any portion of the desired file
locked.

-a