From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266107AbUBGBgv (ORCPT ); Fri, 6 Feb 2004 20:36:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266243AbUBGBgv (ORCPT ); Fri, 6 Feb 2004 20:36:51 -0500 Received: from inet-mail1.oracle.com ([148.87.2.201]:7876 "EHLO inet-mail1.oracle.com") by vger.kernel.org with ESMTP id S266107AbUBGBgi (ORCPT ); Fri, 6 Feb 2004 20:36:38 -0500 Date: Fri, 6 Feb 2004 17:35:53 -0800 From: Joel Becker To: Matthias Urlichs Cc: linux-kernel@vger.kernel.org Subject: Re: VFS locking: f_pos thread-safe ? Message-ID: <20040207013553.GW4902@ca-server1.us.oracle.com> Mail-Followup-To: Matthias Urlichs , linux-kernel@vger.kernel.org References: <20040206041223.A18820@almesberger.net> <20040206183746.GR4902@ca-server1.us.oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Burt-Line: Trees are cool. X-Red-Smith: Ninety feet between bases is perhaps as close as man has ever come to perfection. User-Agent: Mutt/1.5.5.1+cvs20040105i X-Brightmail-Tracker: AAAAAQAAAAI= X-White-List-Member: TRUE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 06, 2004 at 08:05:48PM +0100, Matthias Urlichs wrote: > thread A reads M @N thread B reads M @N file pointer ends up as N+M > thread A reads M @N thread B reads M @M+N file pointer ends up as N+2M > thread A reads M @M+N thread B reads M @N file pointer ends up as N+2M > > With your description, > thread A reads M @M+N thread B reads M @M+N file pointer ends up as N+2M I didn't mean the last. I was just writing English, and figured everyone would know what I meant. Obviously, the first read() in starts @M. Joel -- Life's Little Instruction Book #198 "Feed a stranger's expired parking meter." Joel Becker Senior Member of Technical Staff Oracle Corporation E-mail: joel.becker@oracle.com Phone: (650) 506-8127