Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263643AbUCUM5q (ORCPT ); Sun, 21 Mar 2004 07:57:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263644AbUCUM5q (ORCPT ); Sun, 21 Mar 2004 07:57:46 -0500 Received: from mail.fh-wedel.de ([213.39.232.194]:34024 "EHLO mail.fh-wedel.de") by vger.kernel.org with ESMTP id S263643AbUCUM5p (ORCPT ); Sun, 21 Mar 2004 07:57:45 -0500 Date: Sun, 21 Mar 2004 13:57:30 +0100 From: =?iso-8859-1?Q?J=F6rn?= Engel To: Davide Libenzi Cc: "Patrick J. LoPresti" , Linux Kernel Mailing List Subject: Re: [PATCH] cowlinks v2 Message-ID: <20040321125730.GB21844@wohnheim.fh-wedel.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1312 Lines: 38 On Sat, 20 March 2004 08:48:43 -0800, Davide Libenzi wrote: > On 20 Mar 2004, Patrick J. LoPresti wrote: > > > What happens if the disk fills while you are making the copy? Will > > open(2) on an *existing file* then return ENOSPC? > > > > I do not think you can implement this without changing the interface > > to open(2). Which means applications have to be made aware of it > > anyway. Which means you might as well leave your implementation as-is > > and let userspace worry about creating the copy (and dealing with the > > resulting errors). > > FWIW I did this quite some time ago to speed up copy+diff linux kernel > trees: > > http://www.xmailserver.org/flcow.html > > It is entirely userspace and uses LD_PRELOAD on my dev shell. Nice work. I was thinking about something like that as an intermediate solution (my goal is libc inclusion), just with slightly different checks: int ret = open(...); if (ret == -EMLINK) ret = cow_open(...); return ret; J?rn -- He that composes himself is wiser than he that composes a book. -- B. Franklin - 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/