1 files changed, 17 insertions, 1 deletions

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index b25d1b53df0d..9ccf0e286b2a 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -149,6 +149,12 @@ struct lock_list {
         struct lock_class               *class;
         struct stack_trace              trace;
         int                             distance;
+
+        /*
+         * The parent field is used to implement breadth-first search, and the
+         * bit 0 is reused to indicate if the lock has been accessed in BFS.
+         */
+        struct lock_list                *parent;
 };
 
 /*
@@ -208,10 +214,12 @@ struct held_lock {
          * interrupt context:
          */
         unsigned int irq_context:2; /* bit 0 - soft, bit 1 - hard */
-        unsigned int trylock:1;
+        unsigned int trylock:1;                                         /* 16 bits */
+
         unsigned int read:2;        /* see lock_acquire() comment */
         unsigned int check:2;       /* see lock_acquire() comment */
         unsigned int hardirqs_off:1;
+        unsigned int references:11;                                     /* 32 bits */
 };
 
 /*
@@ -291,6 +299,10 @@ extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 extern void lock_release(struct lockdep_map *lock, int nested,
                          unsigned long ip);
 
+#define lockdep_is_held(lock)   lock_is_held(&(lock)->dep_map)
+
+extern int lock_is_held(struct lockdep_map *lock);
+
 extern void lock_set_class(struct lockdep_map *lock, const char *name,
                            struct lock_class_key *key, unsigned int subclass,
                            unsigned long ip);
@@ -309,6 +321,8 @@ extern void lockdep_trace_alloc(gfp_t mask);
 
 #define lockdep_depth(tsk)      (debug_locks ? (tsk)->lockdep_depth : 0)
 
+#define lockdep_assert_held(l)  WARN_ON(debug_locks && !lockdep_is_held(l))
+
 #else /* !LOCKDEP */
 
 static inline void lockdep_off(void)
@@ -353,6 +367,8 @@ struct lock_class_key { };
 
 #define lockdep_depth(tsk)      (0)
 
+#define lockdep_assert_held(l)                  do { } while (0)
+
 #endif /* !LOCKDEP */
 
 #ifdef CONFIG_LOCK_STAT