From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754415AbXDQOhS (ORCPT ); Tue, 17 Apr 2007 10:37:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754420AbXDQOhR (ORCPT ); Tue, 17 Apr 2007 10:37:17 -0400 Received: from cs.columbia.edu ([128.59.16.20]:58907 "EHLO cs.columbia.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754415AbXDQOhP (ORCPT ); Tue, 17 Apr 2007 10:37:15 -0400 Message-ID: <4624DB46.6040400@cs.columbia.edu> Date: Tue, 17 Apr 2007 10:35:50 -0400 From: Shaya Potter User-Agent: Thunderbird 2.0.0.0 (X11/20070326) MIME-Version: 1.0 To: bharata@linux.vnet.ibm.com CC: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Jan Blunck Subject: Re: [RFC][PATCH 0/15] VFS based Union Mount References: <20070417131459.GA4001@in.ibm.com> In-Reply-To: <20070417131459.GA4001@in.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-PerlMx-Spam: Gauge=IIIIIII, Probability=7%, X-Seen-By filter1.cs.columbia.edu Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Bharata B Rao wrote: > Hi, > > Here is an attempt towards vfs based union mount implementation. > Union mount provides the filesytem namespace unification feature. > Unlike the traditional mounts which hide the contents of the mount point, > the union mount presents the merged view of the mount point and the > mounted filesytem. does this approach allow one to add directories to the union and have it behave normally. namely when imagine one has the situation dir-b dir-a/ (contains file foo) if one unions this and deletes foo, that will create a whiteout entry in dir-a now, what happens if one does dir-c dir-b (now contains whiteout, from previous union). dir-a (contains file foo) will one see foo or not. i.e. are whiteouts only looked for in the topmost dir, or in every dir?