From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271405AbTHDPFO (ORCPT ); Mon, 4 Aug 2003 11:05:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271807AbTHDPFN (ORCPT ); Mon, 4 Aug 2003 11:05:13 -0400 Received: from mail3.ithnet.com ([217.64.64.7]:60094 "HELO heather-ng.ithnet.com") by vger.kernel.org with SMTP id S271405AbTHDPFI (ORCPT ); Mon, 4 Aug 2003 11:05:08 -0400 X-Sender-Authentification: SMTPafterPOP by from 217.64.64.14 Date: Mon, 4 Aug 2003 17:05:06 +0200 From: Stephan von Krawczynski To: Jesse Pollard Cc: aebr@win.tue.nl, linux-kernel@vger.kernel.org Subject: Re: FS: hardlinks on directories Message-Id: <20030804170506.11426617.skraw@ithnet.com> In-Reply-To: <03080409334500.03650@tabby> References: <20030804141548.5060b9db.skraw@ithnet.com> <20030804134415.GA4454@win.tue.nl> <20030804155604.2cdb96e7.skraw@ithnet.com> <03080409334500.03650@tabby> Organization: ith Kommunikationstechnik GmbH X-Mailer: Sylpheed version 0.9.4 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 4 Aug 2003 09:33:44 -0500 Jesse Pollard wrote: > Find for one. Any application that must scan the tree in a search. Any > application that must backup every file for another (I know, dump bypasses > the filesystem to make backups, tar doesn't). All that can handle symlinks already have the same problem nowadays. Where is the difference? And yet again: it is no _must_ for the feature to use it for creating complete loops inside your fs. You _can_ as well dd if=/dev/zero of=/dev/hda, but of course you shouldn't. Have you therefore deleted dd from your bin ? > It introduces too many unique problems to be easily handled. That is why > symbolic links actually work. Symbolic links are not hard links, therefore > they are not processed as part of the tree. and do not cause loops. tar --dereference loops on symlinks _today_, to name an example. All you have to do is to provide a way to find out if a directory is a hardlink, nothing more. And that should be easy. > It was also done in one of the "popular" code management systems under > unix. (it allowed a "mount" of the system root to be under the CVS > repository to detect unauthorized modifications...). Unfortunately, > the system could not be backed up anymore. 1. A dump of the CVS filesystem > turned into a dump of the entire system... 2. You could not restore the > backups... The dumps failed (bru at the time) because the pathnames got > too long, the restore failed since it ran out of disk space due to the > multiple copies of the tree being created. And they never heard of "--exclude" in tar, did they? > The KIS principle is the key. A graph is NOT simple to maintain. This is true. But I am very willing to believe reiserfs is not simple either, still it is there ;-) Regards, Stephan