From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: [PATCH 0/6] Unshare support for the pid namespace. Date: Sun, 20 Jun 2010 01:42:37 -0700 Message-ID: References: <1276706068-18567-1-git-send-email-louis.rilling@kerlabs.com> <20100617212003.GA4182@redhat.com> <20100618082033.GD16877@hawkmoon.kerlabs.com> <20100618111554.GA3252@redhat.com> <20100618160849.GA7404@redhat.com> <20100618173320.GG16877@hawkmoon.kerlabs.com> <20100618175541.GA13680@redhat.com> <20100618212355.GA29478@redhat.com> <20100619190840.GA3424@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <20100619190840.GA3424@redhat.com> (Oleg Nesterov's message of "Sat\, 19 Jun 2010 21\:08\:40 +0200") Sender: linux-kernel-owner@vger.kernel.org To: Oleg Nesterov Cc: Andrew Morton , Louis Rilling , Pavel Emelyanov , Linux Containers , linux-kernel@vger.kernel.org, Daniel Lezcano List-Id: containers.vger.kernel.org Oleg Nesterov writes: > On 06/18, Oleg Nesterov wrote: >> >> I only try to discuss the idea to break the circular reference. > > I don't know what I have missed, but this looks really right to me. > Besides, we have yet another problem: proc_flush_task()->mntput() > is just wrong. Consider the multithreaded execing init. > > I am going to simplify, test, and send the fix which moves mntput() > into free_pid_ns() paths. free_pid_ns is comparatively late, to release the kern_mount. > But first of all I think we should cleanup the pid_ns_prepare_proc() > logic. Imho, this code is really ugly. Please see the patches. Since I have a patchset that makes it possible to unshare the pid namespace about ready to send I figure we should combine the two efforts. This patchset is a prerequisite to my patches for giving namespaces file descriptors and allowing you to join and existing namespace. When I look over my old notes it appears there Daniel managed to hit this proc_mnt reference counting in that context. So that is definitely interesting. Oleg take a look I think I have combined the best of our two patchsets. Eric