Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754868AbWL1PZO (ORCPT ); Thu, 28 Dec 2006 10:25:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754870AbWL1PZN (ORCPT ); Thu, 28 Dec 2006 10:25:13 -0500 Received: from gw-e.panasas.com ([65.194.124.178]:55205 "EHLO cassoulet.panasas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754868AbWL1PZM (ORCPT ); Thu, 28 Dec 2006 10:25:12 -0500 Message-ID: <4593E1B7.6080408@panasas.com> Date: Thu, 28 Dec 2006 17:24:39 +0200 From: Benny Halevy User-Agent: Thunderbird 1.5.0.7 (X11/20060909) MIME-Version: 1.0 To: Arjan van de Ven CC: Mikulas Patocka , Jan Harkes , Miklos Szeredi , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, nfsv4@ietf.org Subject: Re: Finding hardlinks References: <20061221185850.GA16807@delft.aura.cs.cmu.edu> <1166869106.3281.587.camel@laptopd505.fenrus.org> <4593890C.8030207@panasas.com> <1167300352.3281.4183.camel@laptopd505.fenrus.org> In-Reply-To: <1167300352.3281.4183.camel@laptopd505.fenrus.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 28 Dec 2006 15:24:23.0051 (UTC) FILETIME=[4096F5B0:01C72A94] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1229 Lines: 32 Arjan van de Ven wrote: >> It seems like the posix idea of unique doesn't >> hold water for modern file systems > > are you really sure? Well Jan's example was of Coda that uses 128-bit internal file ids. > and if so, why don't we fix *THAT* instead Hmm, sometimes you can't fix the world, especially if the filesystem is exported over NFS and has a problem with fitting its file IDs uniquely into a 64-bit identifier. > rather than adding racy > syscalls and such that just can't really be used right... > If the syscall is working on two pathnames I agree there might be a race that isn't different from calling lstat() on each of these names before opening them. But I'm not sure I see a race if you operate on two open file descriptors (compared to fstat()ing both of them) On the nfs side, if the client looked up two names (or opened them over nfsv4) and has two filehandles in hand, asking the server whether they refer to the same object isn't racy. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/