Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761667AbYFZNNe (ORCPT ); Thu, 26 Jun 2008 09:13:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758219AbYFZNIA (ORCPT ); Thu, 26 Jun 2008 09:08:00 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:48121 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754025AbYFZNH6 (ORCPT ); Thu, 26 Jun 2008 09:07:58 -0400 Date: Thu, 26 Jun 2008 08:07:52 -0500 From: "Serge E. Hallyn" To: "Eric W. Biederman" Cc: "Serge E. Hallyn" , Tejun Heo , Benjamin Thery , Greg Kroah-Hartman , Andrew Morton , Daniel Lezcano , linux-kernel@vger.kernel.org, Al Viro , Linux Containers Subject: Re: [PATCH 11/11] sysfs: user namespaces: fix bug with clone(CLONE_NEWUSER) with fairsched Message-ID: <20080626130752.GA11002@us.ibm.com> References: <20080618170729.808539948@theryb.frec.bull.fr> <20080618170731.746054454@theryb.frec.bull.fr> <485F0812.4090903@gmail.com> <20080625184409.GA8353@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1600 Lines: 35 Quoting Eric W. Biederman (ebiederm@xmission.com): > "Serge E. Hallyn" writes: > > > Except the sysfs mount holds no refcount on the userns. So as long as we > > do the ida tagging as you suggested in your response to patch 6, there > > should be no reference to the user_ns left in sysfs code. > > > > The extra reference in patch #9 is for a light ref on the network > > namespace. I'm still not sure that needs to be there, since if the > > network namespace goes away, it will properly unregister its sysfs > > mounts. Eric, Benjamin, I really don't see any use for the hold_net() > > from sysfs. What is it doing? > > Mostly just being a sanity check. We can remove that if it easier. > > Eric In itself it seems an ok check (temporarily) to make sure that the net_ns hook to unset the tag.netns at netns release is properly working, but given that it's only checking for net_ns coding errors, and Tejun wants a whole generic hooking infrastructure for net_ns to register with so as to keep mention of net_ns out of sysfs code, yeah I think the sane thing is to just remove it. But the first thing (after Daniel is finished with the patch 5 fallout) is to address the patch 6 comments about using ida. At first I didn't like it (seemed like too much bookkeeping) but I think it'll actually work out very nicely. -serge -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/