From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Re: [RFC] shared subtrees Date: Tue, 1 Feb 2005 21:10:20 -0500 Message-ID: <20050202021020.GC23662@fieldses.org> References: <20050113221851.GI26051@parcelfarce.linux.theplanet.co.uk> <41FABD4E.6050701@sun.com> <1107224911.8118.65.camel@localhost> <41FF2985.8000903@sun.com> <1107286073.8118.80.camel@localhost> <41FFF178.902@sun.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ram , Al Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Received: from dsl093-002-214.det1.dsl.speakeasy.net ([66.93.2.214]:28084 "EHLO pickle.fieldses.org") by vger.kernel.org with ESMTP id S262203AbVBBCKV (ORCPT ); Tue, 1 Feb 2005 21:10:21 -0500 To: Mike Waychison Content-Disposition: inline In-Reply-To: <41FFF178.902@sun.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Tue, Feb 01, 2005 at 04:15:36PM -0500, Mike Waychison wrote: > No. I want to allow the mount. However, if there are several shared > '/home' (through CLONE_NS or mount --bind), there remains the following > two key problems: > > - - How do you expire the mounts and umount them? (undefined with shared > subtrees thus far) > - - How do you handle the case where '/home/mikew' is automounted in all > instances of it, and then umounted in a single namespace. Walking back > into '/home/mikew' in that namespace will trigger the daemon to mount > again, but the filesystem is already mounted in it's namespace. > > I guess a solution to ponder is what if we included the following rule: > > "An attempt to umount a vfsmount X will induce the umounting of all > vfsmounts in X's p-node as well as all vfsmounts/p-nodes 'owned' by said > p-node." >>From Viro's proposal: > 5. umount > umount everything that gets propagation from victim. I think that agrees with your description. What *should* be the behaviour when someone unmounts something that was mounted by the automounter? That seems like a strange thing to do. --b.