From owner-freebsd-standards@FreeBSD.ORG  Fri Nov 16 00:27:50 2007
Return-Path: <owner-freebsd-standards@FreeBSD.ORG>
Delivered-To: standards@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 2F96A16A419
	for <standards@FreeBSD.org>; Fri, 16 Nov 2007 00:27:50 +0000 (UTC)
	(envelope-from kris@FreeBSD.org)
Received: from weak.local (freefall.freebsd.org [IPv6:2001:4f8:fff6::28])
	by mx1.freebsd.org (Postfix) with ESMTP id 880A313C4C5;
	Fri, 16 Nov 2007 00:27:49 +0000 (UTC)
	(envelope-from kris@FreeBSD.org)
Message-ID: <473CE408.1030901@FreeBSD.org>
Date: Fri, 16 Nov 2007 01:27:52 +0100
From: Kris Kennaway <kris@FreeBSD.org>
User-Agent: Thunderbird 2.0.0.6 (Macintosh/20070728)
MIME-Version: 1.0
To: Bruce Evans <brde@optusnet.com.au>
References: <473CC2A0.8020603@FreeBSD.org>
	<20071116110621.U10808@besplex.bde.org>
In-Reply-To: <20071116110621.U10808@besplex.bde.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: standards@FreeBSD.org
Subject: Re: Variant behaviour from truncate over NFS and UFS
X-BeenThere: freebsd-standards@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Standards compliance <freebsd-standards.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-standards>, 
	<mailto:freebsd-standards-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-standards>
List-Post: <mailto:freebsd-standards@freebsd.org>
List-Help: <mailto:freebsd-standards-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-standards>, 
	<mailto:freebsd-standards-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 16 Nov 2007 00:27:50 -0000

Bruce Evans wrote:
> On Thu, 15 Nov 2007, Kris Kennaway wrote:
> 
>> I came across the following variant behaviour.  On NFS:
>>
>> hydra1# cd /nfs
>> hydra1# touch foo
>> hydra1# chmod a-w foo
>> hydra1# ls -l foo
>> -r--r--r--  1 4294967294  wheel  0 Nov 15 21:57 foo
>> hydra1# truncate -s 0 foo
>> truncate: foo: Permission denied
>> hydra1# chmod u+w foo
>> hydra1# truncate -s 0 foo
>>
>> Compare to UFS:
>>
>> hydra1# cd /tmp
>> hydra1# touch foo
>> hydra1# chmod a-w foo
>> hydra1# truncate -s 0 foo
>> hydra1# ls -l foo
>> -r--r--r--  1 root  wheel  0 Nov 15 21:57 foo
>>
>> Which is correct?
> 
> Both, I think.  truncate(2) requires write permission, and root always
> has write permission, but root isn't really root for the nfs case.
> 
> Anyway, the default of maproot=-2 gives much more annoying nonstandard
> behaviour than this -- it often prevents root doing things that normal
> users can do.

Ah yes, thanks for clarifying.

Kris