rtmutex_api: provide correct extern functions

Commit fb49f07ba1d9 ("locking/mutex: implement mutex_lock_killable_nest_lock")
changed the set of functions that mutex.c defines when CONFIG_DEBUG_LOCK_ALLOC
is set.

- it removed the "extern" declaration of mutex_lock_killable_nested from
  include/linux/mutex.h, and replaced it with a macro since it could be
  treated as a special case of _mutex_lock_killable.  It also removed a
  definition of the function in kernel/locking/mutex.c.

- likewise, it replaced mutex_trylock() with the more generic
  mutex_trylock_nest_lock() and replaced mutex_trylock() with a macro.

However, it left the old definitions in place in kernel/locking/rtmutex_api.c,
which causes failures when building with CONFIG_RT_MUTEXES=y.  Bring over
the changes.

Fixes: fb49f07ba1d9 ("locking/mutex: implement mutex_lock_killable_nest_lock")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/kernel/locking/rtmutex_api.c b/kernel/locking/rtmutex_api.c
index 191e472..2d93352 100644 (file)
--- a/kernel/locking/rtmutex_api.c
+++ b/kernel/locking/rtmutex_api.c
@@ -544,12 +544,12 @@ int __sched mutex_lock_interruptible_nested(struct mutex *lock,
 }
 EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
 
-int __sched mutex_lock_killable_nested(struct mutex *lock,
-                                           unsigned int subclass)
+int __sched _mutex_lock_killable(struct mutex *lock, unsigned int subclass,
+                                struct lockdep_map *nest_lock)
 {
-       return __mutex_lock_common(lock, TASK_KILLABLE, subclass, NULL, _RET_IP_);
+       return __mutex_lock_common(lock, TASK_KILLABLE, subclass, nest_lock, _RET_IP_);
 }
-EXPORT_SYMBOL_GPL(mutex_lock_killable_nested);
+EXPORT_SYMBOL_GPL(_mutex_lock_killable);
 
 void __sched mutex_lock_io_nested(struct mutex *lock, unsigned int subclass)
 {
@@ -563,6 +563,21 @@ void __sched mutex_lock_io_nested(struct mutex *lock, unsigned int subclass)
 }
 EXPORT_SYMBOL_GPL(mutex_lock_io_nested);
 
+int __sched _mutex_trylock_nest_lock(struct mutex *lock,
+                                    struct lockdep_map *nest_lock)
+{
+       int ret;
+
+       if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task()))
+               return 0;
+
+       ret = __rt_mutex_trylock(&lock->rtmutex);
+       if (ret)
+               mutex_acquire_nest(&lock->dep_map, 0, 1, nest_lock, _RET_IP_);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(_mutex_trylock_nest_lock);
 #else /* CONFIG_DEBUG_LOCK_ALLOC */
 
 void __sched mutex_lock(struct mutex *lock)
@@ -591,22 +606,16 @@ void __sched mutex_lock_io(struct mutex *lock)
        io_schedule_finish(token);
 }
 EXPORT_SYMBOL(mutex_lock_io);
-#endif /* !CONFIG_DEBUG_LOCK_ALLOC */
 
 int __sched mutex_trylock(struct mutex *lock)
 {
-       int ret;
-
        if (IS_ENABLED(CONFIG_DEBUG_RT_MUTEXES) && WARN_ON_ONCE(!in_task()))
                return 0;
 
-       ret = __rt_mutex_trylock(&lock->rtmutex);
-       if (ret)
-               mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
-
-       return ret;
+       return __rt_mutex_trylock(&lock->rtmutex);
 }
 EXPORT_SYMBOL(mutex_trylock);
+#endif /* !CONFIG_DEBUG_LOCK_ALLOC */
 
 void __sched mutex_unlock(struct mutex *lock)
 {