From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754411Ab0I0FmZ (ORCPT ); Mon, 27 Sep 2010 01:42:25 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:43136 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753200Ab0I0FmX (ORCPT ); Mon, 27 Sep 2010 01:42:23 -0400 Date: Sun, 26 Sep 2010 22:42:05 -0700 From: Ram Pai To: Valerie Aurora Cc: Ram Pai , Ram Pai , Alexander Viro , Miklos Szeredi , Christoph Hellwig , Andreas Gruenbacher , Nick Piggin , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 03/34] VFS: Add CL_NO_SLAVE flag to clone_mnt()/copy_tree() Message-ID: <20100927054205.GE4999@ram-laptop> Reply-To: Ram Pai References: <1284675145-4391-1-git-send-email-vaurora@redhat.com> <1284675145-4391-4-git-send-email-vaurora@redhat.com> <20100917043401.GD8926@ram-laptop> <20100917171514.GA32258@shell> <20100920052553.GM8926@ram-laptop> <20100921000344.GB9032@shell> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100921000344.GB9032@shell> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 20, 2010 at 08:03:44PM -0400, Valerie Aurora wrote: > On Sun, Sep 19, 2010 at 10:25:53PM -0700, Ram Pai wrote: > > > > I understand your intentions, but I think you are making a wrong assumption. > > You seem to be thinking that if a slave-mount is cloned, the new cloned > > mount will also be a slave-mount and will hence receive propagations. As > > per shared subtree semantics, a slave-mount when cloned will create a private > > mount. Since your intention is to avoid generating any new mounts that > > recieve propagations, you should be checking for shared-mounts and > > slave-shared-mounts because these are the two kind of mounts that when > > cloned create new mounts that receive propagation. > > No. This isn't about the semantics of the clone mount operation. It > is about the administrator creating a slave mount, unioning it, and > then being surprised when the unioned file system does not receive > mount propagation events. > > Think of the source vfsmount tree as a set of command line arguments > for the union mount. Ok. In that case, you introduced a subtle change in the semantics of clone_mnt(). As I understand it, the flags parameter of clone_mnt() are meant to be a modifier for the cloned mount, not a filter on the source mount. RP