From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f196.google.com ([209.85.215.196]:35938 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726193AbeL2AED (ORCPT ); Fri, 28 Dec 2018 19:04:03 -0500 From: Andrei Vagin To: Alexander Viro , David Howells Cc: linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org, Andrei Vagin , Li Zefan Subject: [PATCH vfs/for-next v2] cgroup: fix top cgroup refcnt leak Date: Fri, 28 Dec 2018 16:04:00 -0800 Message-Id: <20181229000400.26333-1-avagin@gmail.com> In-Reply-To: <20181228235900.21468-1-avagin@gmail.com> References: <20181228235900.21468-1-avagin@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: It looks like the c6b3d5bcd67c ("cgroup: fix top cgroup refcnt leak") commit was reverted by mistake. $ mkdir /tmp/cgroup $ mkdir /tmp/cgroup2 $ mount -t cgroup -o none,name=test test /tmp/cgroup $ mount -t cgroup -o none,name=test test /tmp/cgroup2 $ umount /tmp/cgroup $ umount /tmp/cgroup2 $ cat /proc/self/cgroup | grep test 12:name=test:/ You can see the test cgroup was not freed. Cc: Li Zefan Fixes: aea3f2676c83 ("kernfs, sysfs, cgroup, intel_rdt: Support fs_context") Signed-off-by: Andrei Vagin --- v2: clean up code and add the vfs/for-next tag kernel/cgroup/cgroup.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index fb0717696895..f63974a3725f 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2047,6 +2047,9 @@ int cgroup_do_get_tree(struct fs_context *fc) ret = 0; if (ctx->kfc.new_sb_created) goto out_cgrp; + else + cgroup_put(&ctx->root->cgrp); + apply_cgroup_root_flags(ctx->flags); return 0; -- 2.17.2