*/
#include <linux/module.h>
+#include <linux/slab.h>
#include <linux/cgroup.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
struct freezer, css);
}
-int cgroup_frozen(struct task_struct *task)
+int cgroup_freezing_or_frozen(struct task_struct *task)
{
struct freezer *freezer;
enum freezer_state state;
task_lock(task);
freezer = task_freezer(task);
- state = freezer->state;
+ if (!freezer->css.cgroup->parent)
+ state = CGROUP_THAWED; /* root cgroup can't be frozen */
+ else
+ state = freezer->state;
task_unlock(task);
- return state == CGROUP_FROZEN;
+ return (state == CGROUP_FREEZING) || (state == CGROUP_FROZEN);
}
/*
* No lock is needed, since the task isn't on tasklist yet,
* so it can't be moved to another cgroup, which means the
* freezer won't be removed and will be valid during this
- * function call.
+ * function call. Nevertheless, apply RCU read-side critical
+ * section to suppress RCU lockdep false positives.
*/
+ rcu_read_lock();
freezer = task_freezer(task);
+ rcu_read_unlock();
/*
* The root cgroup is non-freezable, so we can skip the