Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754395AbaDYTiE (ORCPT ); Fri, 25 Apr 2014 15:38:04 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:40371 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753900AbaDYTiB (ORCPT ); Fri, 25 Apr 2014 15:38:01 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Andy Lutomirski Cc: "linux-kernel\@vger.kernel.org" , "Serge E. Hallyn" , Linux Containers References: Date: Fri, 25 Apr 2014 12:37:29 -0700 In-Reply-To: (Andy Lutomirski's message of "Fri, 25 Apr 2014 08:58:15 -0700") Message-ID: <87ha5h42va.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-AID: U2FsdGVkX1/cd3ByQEg+WwOIk3Ef2yDcuc04om5TXMs= X-SA-Exim-Connect-IP: 98.234.51.111 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -0.0 BAYES_20 BODY: Bayes spam probability is 5 to 20% * [score: 0.1395] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Andy Lutomirski X-Spam-Relay-Country: Subject: Re: pid ns feature request X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Wed, 14 Nov 2012 13:58:17 -0700) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andy Lutomirski writes: > Unless I'm missing some trick, it's currently rather painful to mount > a namespace /proc. You have to actually be in the pid namespace to > mount the correct /proc instance, and you can't unmount the old /proc > until you've mounted the new /proc. This means that you have to fork > into the new pid namespace before you can finish setting it up. Yes. You have to be inside just about all namespaces before you can finish setting them up. I don't know the context in which needed to be inside the pid namespace is a burden. > Would it make sense to add a mount option to procfs to request a mount > for pid_ns_for_children instead of task_active_pid_ns? This is about the using setns and unshare? Adding a proc amount option that takes a pid namespace file descriptor would be the general solution, and might be worth implementing. Getting a pid namespace file descriptors when there are no pids might be a challenge. Eric -- 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/