From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753293AbaFCEGS (ORCPT ); Tue, 3 Jun 2014 00:06:18 -0400 Received: from [119.145.14.64] ([119.145.14.64]:45688 "EHLO szxga01-in.huawei.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753065AbaFCEGQ (ORCPT ); Tue, 3 Jun 2014 00:06:16 -0400 Message-ID: <538D4982.10905@huawei.com> Date: Tue, 3 Jun 2014 12:05:22 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Tejun Heo CC: LKML , Cgroups Subject: [PATCH 2/3] cgroup: make the default root invisible when it's umounted References: <538D4956.5050205@huawei.com> In-Reply-To: <538D4956.5050205@huawei.com> Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.18.230] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Before this patch (in a fresh system): # cat /proc/$$/cgroup # mount -t cgroup -o __DEVEL__sane_behavior xxx /cgroup # umount /cgroup # cat /proc/$$/cgroup 0:cpuset,cpu,cpuacct,memory,devices,freezer,net_cls,blkio,perf_event,net_prio,hugetlb:/ After this patch (in a fresh system): # cat ... # mount ... # umount ... # cat /proc/$$/cgroup # You won't see the default root after it's umounted. Signed-off-by: Li Zefan --- kernel/cgroup.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index f73fe48..dabc486 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1788,6 +1788,8 @@ static void cgroup_kill_sb(struct super_block *sb) } else { if (root != &cgrp_dfl_root) percpu_ref_kill(&root->cgrp.self.refcnt); + else + cgrp_dfl_root_visible = false; } kernfs_kill_sb(sb); -- 1.8.0.2