Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm

[sfrench/cifs-2.6.git] / kernel / ns_cgroup.c

diff --git a/kernel/ns_cgroup.c b/kernel/ns_cgroup.c
index 43c2111cd54de719917c0cdc9ace9e92445f4513..5aa854f9e5ae0cae90d37d7594d265cdbab6fc01 100644 (file)
--- a/kernel/ns_cgroup.c
+++ b/kernel/ns_cgroup.c
@@ -13,7 +13,6 @@
 
 struct ns_cgroup {
        struct cgroup_subsys_state css;
-       spinlock_t lock;
 };
 
 struct cgroup_subsys ns_subsys;
@@ -35,7 +34,7 @@ int ns_cgroup_clone(struct task_struct *task, struct pid *pid)
 
 /*
  * Rules:
- *   1. you can only enter a cgroup which is a child of your current
+ *   1. you can only enter a cgroup which is a descendant of your current
  *     cgroup
  *   2. you can only place another process into a cgroup if
  *     a. you have CAP_SYS_ADMIN
@@ -46,21 +45,15 @@ int ns_cgroup_clone(struct task_struct *task, struct pid *pid)
 static int ns_can_attach(struct cgroup_subsys *ss,
                struct cgroup *new_cgroup, struct task_struct *task)
 {
-       struct cgroup *orig;
-
        if (current != task) {
                if (!capable(CAP_SYS_ADMIN))
                        return -EPERM;
 
-               if (!cgroup_is_descendant(new_cgroup))
+               if (!cgroup_is_descendant(new_cgroup, current))
                        return -EPERM;
        }
 
-       if (atomic_read(&new_cgroup->count) != 0)
-               return -EPERM;
-
-       orig = task_cgroup(task, ns_subsys_id);
-       if (orig && orig != new_cgroup->parent)
+       if (!cgroup_is_descendant(new_cgroup, task))
                return -EPERM;
 
        return 0;
@@ -78,13 +71,12 @@ static struct cgroup_subsys_state *ns_create(struct cgroup_subsys *ss,
 
        if (!capable(CAP_SYS_ADMIN))
                return ERR_PTR(-EPERM);
-       if (!cgroup_is_descendant(cgroup))
+       if (!cgroup_is_descendant(cgroup, current))
                return ERR_PTR(-EPERM);
 
        ns_cgroup = kzalloc(sizeof(*ns_cgroup), GFP_KERNEL);
        if (!ns_cgroup)
                return ERR_PTR(-ENOMEM);
-       spin_lock_init(&ns_cgroup->lock);
        return &ns_cgroup->css;
 }