From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030303AbWGZBBE (ORCPT ); Tue, 25 Jul 2006 21:01:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030304AbWGZBBE (ORCPT ); Tue, 25 Jul 2006 21:01:04 -0400 Received: from inti.inf.utfsm.cl ([200.1.21.155]:13003 "EHLO inti.inf.utfsm.cl") by vger.kernel.org with ESMTP id S1030303AbWGZBBC (ORCPT ); Tue, 25 Jul 2006 21:01:02 -0400 Message-Id: <200607260100.k6Q10miJ007619@laptop13.inf.utfsm.cl> To: 7eggert@gmx.de cc: "Horst H. von Brand" , Joshua Hudson , linux-kernel@vger.kernel.org Subject: Re: what is necessary for directory hard links In-Reply-To: Message from Bodo Eggert <7eggert@elstempel.de> of "Tue, 25 Jul 2006 23:28:29 +0200." X-Mailer: MH-E 7.4.2; nmh 1.1; XEmacs 21.4 (patch 19) Date: Tue, 25 Jul 2006 21:00:48 -0400 From: "Horst H. von Brand" X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.0.2 (inti.inf.utfsm.cl [200.1.19.1]); Tue, 25 Jul 2006 21:00:57 -0400 (CLT) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Bodo Eggert <7eggert@elstempel.de> wrote: > Horst H. von Brand wrote: > > Joshua Hudson wrote: > > > [...] > > > >> Maybe someday I'll work out a system by which much less is locked. > >> Conceptually, all that is requred to lock for the algorithm > >> to work is creating hard-links to directories and renaming directories > >> cross-directory. > > > > Some 40 years of filesystem development without finding a solution to that > > conundrum would make that quite unlikely, but you are certainly welcome to > > try. > There is a simple solution against loops: No directory may contain a > directory with a lower inode number. This is a serious restriction... > Off cause this would interfere with normal operations, so you'll allocate all > normal inodes above e.g. 0x800000 and don't test between those inodes. And allow loops there? I don't see how that solves anything... > If you want to hardlink, you'll use a different (privileged) mkdir call > that will allocate a choosen low inode number. This is also required for > the parents of the hardlinked directories. Argh... even /more/ illogical restrictions! > You can also use the generic solution: Allow root to shoot his feet, and > make sure the gun works correctly. ;-) -- Dr. Horst H. von Brand User #22616 counter.li.org Departamento de Informatica Fono: +56 32 654431 Universidad Tecnica Federico Santa Maria +56 32 654239 Casilla 110-V, Valparaiso, Chile Fax: +56 32 797513