Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261672AbUC0K2m (ORCPT ); Sat, 27 Mar 2004 05:28:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261660AbUC0K2m (ORCPT ); Sat, 27 Mar 2004 05:28:42 -0500 Received: from mail.shareable.org ([81.29.64.88]:11154 "EHLO mail.shareable.org") by vger.kernel.org with ESMTP id S261672AbUC0K2k (ORCPT ); Sat, 27 Mar 2004 05:28:40 -0500 Date: Sat, 27 Mar 2004 10:28:28 +0000 From: Jamie Lokier To: "Eric W. Biederman" Cc: =?iso-8859-1?Q?J=F6rn?= Engel , Davide Libenzi , "Patrick J. LoPresti" , Linux Kernel Mailing List Subject: Re: [PATCH] cowlinks v2 Message-ID: <20040327102828.GA21884@mail.shareable.org> References: <20040321125730.GB21844@wohnheim.fh-wedel.de> <20040321181430.GB29440@wohnheim.fh-wedel.de> <20040325174942.GC11236@mail.shareable.org> <20040325194303.GE11236@mail.shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1104 Lines: 25 Eric W. Biederman wrote: > It is easy to add something like a cowstat or a readcowlink and teach > the few programs that care (i.e. diff, tar,...) how to use it. So I > would rather concentrate on making cow links look like a separate copy > than early optimizations. I agree, having each cowlink look like a separate copy, with separate inode numbers, is best. That _is_ POSIX compatible -- the sharing is just a storage optimisation, and programs which only use the POSIX API won't see the difference. I have no problem with adding cowstat() to diff, and I'm sure other people will eventually extend rsync and tar to use it, if it becomes widely used. It's not the simplest solution, though. The filesystem changes are non-trivial. (The simplest solution is just an ext2 attribute which says you can't write to the file if it has >1 links). -- Jamie - 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/