--- a/include/linux/rwlock_api_smp.h~locking-rwlocks-introduce-write_lock_nested
+++ a/include/linux/rwlock_api_smp.h
@@ -17,6 +17,7 @@
 
 void __lockfunc _raw_read_lock(rwlock_t *lock)		__acquires(lock);
 void __lockfunc _raw_write_lock(rwlock_t *lock)		__acquires(lock);
+void __lockfunc _raw_write_lock_nested(rwlock_t *lock, int subclass)	__acquires(lock);
 void __lockfunc _raw_read_lock_bh(rwlock_t *lock)	__acquires(lock);
 void __lockfunc _raw_write_lock_bh(rwlock_t *lock)	__acquires(lock);
 void __lockfunc _raw_read_lock_irq(rwlock_t *lock)	__acquires(lock);
@@ -209,6 +210,13 @@ static inline void __raw_write_lock(rwlo
 	LOCK_CONTENDED(lock, do_raw_write_trylock, do_raw_write_lock);
 }
 
+static inline void __raw_write_lock_nested(rwlock_t *lock, int subclass)
+{
+	preempt_disable();
+	rwlock_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+	LOCK_CONTENDED(lock, do_raw_write_trylock, do_raw_write_lock);
+}
+
 #endif /* !CONFIG_GENERIC_LOCKBREAK || CONFIG_DEBUG_LOCK_ALLOC */
 
 static inline void __raw_write_unlock(rwlock_t *lock)
--- a/include/linux/rwlock.h~locking-rwlocks-introduce-write_lock_nested
+++ a/include/linux/rwlock.h
@@ -55,6 +55,12 @@ do {								\
 #define write_lock(lock)	_raw_write_lock(lock)
 #define read_lock(lock)		_raw_read_lock(lock)
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+#define write_lock_nested(lock, subclass)	_raw_write_lock_nested(lock, subclass)
+#else
+#define write_lock_nested(lock, subclass)	_raw_write_lock(lock)
+#endif
+
 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
 
 #define read_lock_irqsave(lock, flags)			\
--- a/include/linux/rwlock_rt.h~locking-rwlocks-introduce-write_lock_nested
+++ a/include/linux/rwlock_rt.h
@@ -28,6 +28,7 @@ extern void rt_read_lock(rwlock_t *rwloc
 extern int rt_read_trylock(rwlock_t *rwlock);
 extern void rt_read_unlock(rwlock_t *rwlock);
 extern void rt_write_lock(rwlock_t *rwlock);
+extern void rt_write_lock_nested(rwlock_t *rwlock, int subclass);
 extern int rt_write_trylock(rwlock_t *rwlock);
 extern void rt_write_unlock(rwlock_t *rwlock);
 
@@ -83,6 +84,15 @@ static __always_inline void write_lock(r
 	rt_write_lock(rwlock);
 }
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static __always_inline void write_lock_nested(rwlock_t *rwlock, int subclass)
+{
+	rt_write_lock_nested(rwlock, subclass);
+}
+#else
+#define write_lock_nested(lock, subclass)	rt_write_lock(((void)(subclass), (lock)))
+#endif
+
 static __always_inline void write_lock_bh(rwlock_t *rwlock)
 {
 	local_bh_disable();
--- a/include/linux/spinlock_api_up.h~locking-rwlocks-introduce-write_lock_nested
+++ a/include/linux/spinlock_api_up.h
@@ -59,6 +59,7 @@
 #define _raw_spin_lock_nested(lock, subclass)	__LOCK(lock)
 #define _raw_read_lock(lock)			__LOCK(lock)
 #define _raw_write_lock(lock)			__LOCK(lock)
+#define _raw_write_lock_nested(lock, subclass)	__LOCK(lock)
 #define _raw_spin_lock_bh(lock)			__LOCK_BH(lock)
 #define _raw_read_lock_bh(lock)			__LOCK_BH(lock)
 #define _raw_write_lock_bh(lock)		__LOCK_BH(lock)
--- a/kernel/locking/spinlock.c~locking-rwlocks-introduce-write_lock_nested
+++ a/kernel/locking/spinlock.c
@@ -300,6 +300,16 @@ void __lockfunc _raw_write_lock(rwlock_t
 	__raw_write_lock(lock);
 }
 EXPORT_SYMBOL(_raw_write_lock);
+
+#ifndef CONFIG_DEBUG_LOCK_ALLOC
+#define __raw_write_lock_nested(lock, subclass)	__raw_write_lock(((void)(subclass), (lock)))
+#endif
+
+void __lockfunc _raw_write_lock_nested(rwlock_t *lock, int subclass)
+{
+	__raw_write_lock_nested(lock, subclass);
+}
+EXPORT_SYMBOL(_raw_write_lock_nested);
 #endif
 
 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE
--- a/kernel/locking/spinlock_rt.c~locking-rwlocks-introduce-write_lock_nested
+++ a/kernel/locking/spinlock_rt.c
@@ -239,6 +239,18 @@ void __sched rt_write_lock(rwlock_t *rwl
 }
 EXPORT_SYMBOL(rt_write_lock);
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __sched rt_write_lock_nested(rwlock_t *rwlock, int subclass)
+{
+	rtlock_might_resched();
+	rwlock_acquire(&rwlock->dep_map, subclass, 0, _RET_IP_);
+	rwbase_write_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT);
+	rcu_read_lock();
+	migrate_disable();
+}
+EXPORT_SYMBOL(rt_write_lock_nested);
+#endif
+
 void __sched rt_read_unlock(rwlock_t *rwlock)
 {
 	rwlock_release(&rwlock->dep_map, _RET_IP_);
