From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268718AbUH3Rvq (ORCPT ); Mon, 30 Aug 2004 13:51:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268719AbUH3Rt0 (ORCPT ); Mon, 30 Aug 2004 13:49:26 -0400 Received: from alpha.Xerox.COM ([13.1.64.93]:46985 "HELO alpha.xerox.com") by vger.kernel.org with SMTP id S268681AbUH3RrP convert rfc822-to-8bit (ORCPT ); Mon, 30 Aug 2004 13:47:15 -0400 Date: Mon, 30 Aug 2004 10:43:58 PDT From: Paul Stewart Subject: Re: silent semantic changes with reiser4 To: Paul Jackson Cc: Hans Reiser , riel@redhat.com, ninja@slaphack.com, torvalds@osdl.org, diegocg@teleline.es, jamie@shareable.org, christophe@saout.de, vda@port.imtp.ilyichevsk.odessa.ua, christer@weinigel.se, spam@tnonline.net, akpm@osdl.org, wichert@wiggy.net, jra@samba.org, hch@lst.de, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, flx@namesys.com, reiserfs-list@namesys.com References: <412F7D63.4000109@namesys.com> <20040827230857.69340aec.pj@sgi.com> In-Reply-To: <20040827230857.69340aec.pj@sgi.com> (from pj@sgi.com on Fri, Aug 27, 2004 at 23:08:57 -0700) X-Mailer: Balsa 2.1.2 Message-Id: <1093887838l.11947l.1l@orlando> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; DelSp=Yes Format=Flowed Content-Disposition: inline Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 2004.08.27 23:08, Paul Jackson wrote: > Hans wrote: > > We create filename/pseudos/backup, and that tells the archiver what > > to do..... > > Instead of exposing the old semantics under a new interface, why not > expose the new semantics under a new interface. Here's another take on the same theme. To see attrs on files, one can either use a newly developed application which can use special new syscalls/flags on syscalls a Paul Jackson recommends. However from an old shell or application one can also open the attribute node on /home/myself/foo.txt by checking out /attr/home/myself/foo.txt/, which points to the "as directory" node on the filesystem that foo.txt points to. The strange part of this idea is that the /attr filesystem wouldn't be conventionally browsable. An opendir() on any path would return the attributes, not the subdirectory contents, even if the target was a conventional directory. File based operations (open(), unlink(), etc) would operate on the "as directory" node of the dirname() of the file argument. The /attr filesystem would be completely virtual, honoring the permissions, crossing filesystems, and inheriting the root directory of the calling process. Just a thought from a Linux fs layman -- certainly one of the Reiser unwashed masses. -- Paul