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From: Li Zefan <lizefan@huawei.com>
To: Tejun Heo <tj@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>, Cgroups <cgroups@vger.kernel.org>
Subject: [PATCH 1/5] cgroup: fix broken css_has_online_children()
Date: Thu, 12 Jun 2014 14:31:31 +0800	[thread overview]
Message-ID: <53994943.60703@huawei.com> (raw)

After running:

  # mount -t cgroup cpu xxx /cgroup && mkdir /cgroup/sub && \
    rmdir /cgroup/sub && umount /cgroup

I found the cgroup root still existed:

  # cat /proc/cgroups
  #subsys_name    hierarchy       num_cgroups     enabled
  cpuset  0       1       1
  cpu     1       1       1
  ...

It turned out css_has_online_children() is broken.

Signed-off-by: Li Zefan <lizefan@huawei.com>
---
 kernel/cgroup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 05b8ca4..1c65f24 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3327,7 +3327,7 @@ bool css_has_online_children(struct cgroup_subsys_state *css)
 
 	rcu_read_lock();
 	css_for_each_child(child, css) {
-		if (css->flags & CSS_ONLINE) {
+		if (child->flags & CSS_ONLINE) {
 			ret = true;
 			break;
 		}
-- 
1.8.0.2

             reply	other threads:[~2014-06-12  6:31 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-12  6:31 Li Zefan [this message]
2014-06-12  6:31 ` [PATCH 2/5] percpu-ref: introduce percpu_ref_alive() Li Zefan
2014-06-12  6:32 ` [PATCH 3/5] cgroup: fix mount failure in a corner case Li Zefan
2014-06-20 19:10   ` Tejun Heo
2014-06-24  1:15     ` Li Zefan
2014-06-12  6:32 ` [PATCH 4/5] kernfs: introduce kernfs_pin_sb() and kernfs_drop_sb() Li Zefan
2014-06-12  6:33 ` [PATCH 5/5] cgroup: fix a race between cgroup_mount() and cgroup_kill_sb() Li Zefan
2014-06-20 19:35   ` Tejun Heo
2014-06-24  1:22     ` Li Zefan
2014-06-24 21:01       ` Tejun Heo
2014-06-25  1:56         ` Li Zefan
2014-06-25 15:00           ` Tejun Heo
2014-06-27  6:32             ` Li Zefan
2014-06-27 15:00               ` Tejun Heo
2014-06-17 19:26 ` [PATCH 1/5] cgroup: fix broken css_has_online_children() Tejun Heo

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