lockdep: change a held lock's class

Impact: introduce new lockdep API

Allow to change a held lock's class. Basically the same as the existing
code to change a subclass therefore reuse all that.

The XFS code will be able to use this to annotate their inode locking.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 8956daf64abd..37a0361f4685 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -314,8 +314,15 @@ extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 extern void lock_release(struct lockdep_map *lock, int nested,
                          unsigned long ip);
 
-extern void lock_set_subclass(struct lockdep_map *lock, unsigned int subclass,
-                              unsigned long ip);
+extern void lock_set_class(struct lockdep_map *lock, const char *name,
+                           struct lock_class_key *key, unsigned int subclass,
+                           unsigned long ip);
+
+static inline void lock_set_subclass(struct lockdep_map *lock,
+                unsigned int subclass, unsigned long ip)
+{
+        lock_set_class(lock, lock->name, lock->key, subclass, ip);
+}
 
 # define INIT_LOCKDEP                           .lockdep_recursion = 0,
 
@@ -333,6 +340,7 @@ static inline void lockdep_on(void)
 
 # define lock_acquire(l, s, t, r, c, n, i)      do { } while (0)
 # define lock_release(l, n, i)                  do { } while (0)
+# define lock_set_class(l, n, k, s, i)          do { } while (0)
 # define lock_set_subclass(l, s, i)             do { } while (0)
 # define lockdep_init()                         do { } while (0)
 # define lockdep_info()                         do { } while (0)