From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Boldi Subject: Re: [RFC] VFS: FS CoW using redirection Date: Sat, 26 Aug 2006 22:05:21 +0300 Message-ID: <200608262205.21397.a1426z@gawab.com> References: <200607082041.54489.a1426z@gawab.com> <20060823172402.GC15851@wohnheim.fh-wedel.de> <20060823180552.GC28873@filer.fsl.cs.sunysb.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1256 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Eric Van Hensbergen , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, =?iso-8859-1?q?J=F6rn=20Engel?= Return-path: Received: from [212.33.164.48] ([212.33.164.48]:14852 "EHLO raad.intranet") by vger.kernel.org with ESMTP id S1751637AbWHZTDk convert rfc822-to-8bit (ORCPT ); Sat, 26 Aug 2006 15:03:40 -0400 To: Josef Sipek In-Reply-To: <20060823180552.GC28873@filer.fsl.cs.sunysb.edu> Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Josef Sipek wrote: > On Wed, Aug 23, 2006 at 07:24:02PM +0200, J=F6rn Engel wrote: > > On Sun, 9 July 2006 15:50:36 +0300, Al Boldi wrote: > > > Consider something simple like this: > > > > > > VFS - anyFS1 (r/w) used normally, unless ENotFound, then redirect= read > > > to \ anyFS2, or CoW from anyFS2 to anyFS1. > > > anyFS2 (r/o) used normally. > > > > That concept is known as union mount. Jan Blunck did some patches = in > > that direction, you might be able to find them in the archives. If > > not, just send him a mail. Thanks for the pointer! So what was the rejecting theme? > Or you can give Unionfs a try: http://www.unionfs.org UnionFS is great, but it incurs additional overhead, as it lives below = the=20 real VFS. What could be really great, is to move some basic functional= ity=20 abstractions from UnionFS into VFS proper. Thanks! -- Al - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html