From: Chen Ridong <chenridong@huawei.com>

Add lockdep_assert_cpuset_lock_held() to allow other subsystems to verify
that cpuset_mutex is held.

Suggested-by: Waiman Long <longman@redhat.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
---
 include/linux/cpuset.h | 2 ++
 kernel/cgroup/cpuset.c | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
index a98d3330385c..a634489c9f12 100644
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -74,6 +74,7 @@ extern void inc_dl_tasks_cs(struct task_struct *task);
 extern void dec_dl_tasks_cs(struct task_struct *task);
 extern void cpuset_lock(void);
 extern void cpuset_unlock(void);
+extern void lockdep_assert_cpuset_lock_held(void);
 extern void cpuset_cpus_allowed_locked(struct task_struct *p, struct cpumask *mask);
 extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask);
 extern bool cpuset_cpus_allowed_fallback(struct task_struct *p);
@@ -195,6 +196,7 @@ static inline void inc_dl_tasks_cs(struct task_struct *task) { }
 static inline void dec_dl_tasks_cs(struct task_struct *task) { }
 static inline void cpuset_lock(void) { }
 static inline void cpuset_unlock(void) { }
+static inline void lockdep_assert_cpuset_lock_held(void) { }
 
 static inline void cpuset_cpus_allowed_locked(struct task_struct *p,
 					struct cpumask *mask)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index fea577b4016a..4fa3080da3be 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -271,6 +271,11 @@ void cpuset_unlock(void)
 	mutex_unlock(&cpuset_mutex);
 }
 
+void lockdep_assert_cpuset_lock_held(void)
+{
+	lockdep_assert_held(&cpuset_mutex);
+}
+
 /**
  * cpuset_full_lock - Acquire full protection for cpuset modification
  *
-- 
2.34.1