Lockdep: add lockdep_set_class_and_subclass() and lockdep_set_subclass()

This annotation makes it possible to assign a subclass on lock init. This
annotation is meant to reduce the _nested() annotations by assigning a
default subclass.

One could do without this annotation and rely on lockdep_set_class()
exclusively, but that would require a manual stack of struct lock_class_key
objects.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/rwsem.c b/lib/rwsem.c
index 901d0e7da892..cdb4e3d05607 100644
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -19,7 +19,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
 	 * Make sure we are not reinitializing a held semaphore:
 	 */
 	debug_check_no_locks_freed((void *)sem, sizeof(*sem));
-	lockdep_init_map(&sem->dep_map, name, key);
+	lockdep_init_map(&sem->dep_map, name, key, 0);
 #endif
 	sem->count = RWSEM_UNLOCKED_VALUE;
 	spin_lock_init(&sem->wait_lock);