1 files changed, 69 insertions, 67 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index f32ca78c198d..9bad17884513 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -169,22 +169,17 @@ EXPORT_SYMBOL(lockdep_internal);
  */
 static int class_filter(struct lock_class *class)
 {
+#if 0
+        /* Example */
         if (class->name_version == 1 &&
-                        !strcmp(class->name, "&rl->lock"))
+                        !strcmp(class->name, "lockname"))
                 return 1;
         if (class->name_version == 1 &&
-                        !strcmp(class->name, "&ni->mrec_lock"))
+                        !strcmp(class->name, "&struct->lockfield"))
                 return 1;
-        if (class->name_version == 1 &&
-                        !strcmp(class->name, "mft_ni_runlist_lock"))
-                return 1;
-        if (class->name_version == 1 &&
-                        !strcmp(class->name, "mft_ni_mrec_lock"))
-                return 1;
-        if (class->name_version == 1 &&
-                        !strcmp(class->name, "&vol->lcnbmp_lock"))
-                return 1;
-        return 0;
+#endif
+        /* Allow everything else. 0 would be filter everything else */
+        return 1;
 }
 #endif
 
@@ -408,23 +403,12 @@ static void lockdep_print_held_locks(struct task_struct *curr)
                 print_lock(curr->held_locks + i);
         }
 }
-/*
- * Helper to print a nice hierarchy of lock dependencies:
- */
-static void print_spaces(int nr)
-{
-        int i;
-
-        for (i = 0; i < nr; i++)
-                printk("  ");
-}
 
 static void print_lock_class_header(struct lock_class *class, int depth)
 {
         int bit;
 
-        print_spaces(depth);
-        printk("->");
+        printk("%*s->", depth, "");
         print_lock_name(class);
         printk(" ops: %lu", class->ops);
         printk(" {\n");
@@ -433,17 +417,14 @@ static void print_lock_class_header(struct lock_class *class, int depth)
                 if (class->usage_mask & (1 << bit)) {
                         int len = depth;
 
-                        print_spaces(depth);
-                        len += printk("   %s", usage_str[bit]);
+                        len += printk("%*s   %s", depth, "", usage_str[bit]);
                         len += printk(" at:\n");
                         print_stack_trace(class->usage_traces + bit, len);
                 }
         }
-        print_spaces(depth);
-        printk(" }\n");
+        printk("%*s }\n", depth, "");
 
-        print_spaces(depth);
-        printk(" ... key      at: ");
+        printk("%*s ... key      at: ",depth,"");
         print_ip_sym((unsigned long)class->key);
 }
 
@@ -463,8 +444,7 @@ static void print_lock_dependencies(struct lock_class *class, int depth)
                 DEBUG_LOCKS_WARN_ON(!entry->class);
                 print_lock_dependencies(entry->class, depth + 1);
 
-                print_spaces(depth);
-                printk(" ... acquired at:\n");
+                printk("%*s ... acquired at:\n",depth,"");
                 print_stack_trace(&entry->trace, 2);
                 printk("\n");
         }
@@ -1124,7 +1104,7 @@ extern void __error_too_big_MAX_LOCKDEP_SUBCLASSES(void);
  * itself, so actual lookup of the hash should be once per lock object.
  */
 static inline struct lock_class *
-register_lock_class(struct lockdep_map *lock, unsigned int subclass)
+look_up_lock_class(struct lockdep_map *lock, unsigned int subclass)
 {
         struct lockdep_subclass_key *key;
         struct list_head *hash_head;
@@ -1168,7 +1148,26 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass)
          */
         list_for_each_entry(class, hash_head, hash_entry)
                 if (class->key == key)
-                        goto out_set;
+                        return class;
+
+        return NULL;
+}
+
+/*
+ * Register a lock's class in the hash-table, if the class is not present
+ * yet. Otherwise we look it up. We cache the result in the lock object
+ * itself, so actual lookup of the hash should be once per lock object.
+ */
+static inline struct lock_class *
+register_lock_class(struct lockdep_map *lock, unsigned int subclass)
+{
+        struct lockdep_subclass_key *key;
+        struct list_head *hash_head;
+        struct lock_class *class;
+
+        class = look_up_lock_class(lock, subclass);
+        if (likely(class))
+                return class;
 
         /*
          * Debug-check: all keys must be persistent!
@@ -1183,6 +1182,9 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass)
                 return NULL;
         }
 
+        key = lock->key->subkeys + subclass;
+        hash_head = classhashentry(key);
+
         __raw_spin_lock(&hash_lock);
         /*
          * We have to do the hash-walk again, to avoid races
@@ -1229,8 +1231,8 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass)
 out_unlock_set:
         __raw_spin_unlock(&hash_lock);
 
-out_set:
-        lock->class[subclass] = class;
+        if (!subclass)
+                lock->class_cache = class;
 
         DEBUG_LOCKS_WARN_ON(class->subclass != subclass);
 
@@ -1934,7 +1936,7 @@ void lockdep_init_map(struct lockdep_map *lock, const char *name,
         }
         lock->name = name;
         lock->key = key;
-        memset(lock->class, 0, sizeof(lock->class[0])*MAX_LOCKDEP_SUBCLASSES);
+        lock->class_cache = NULL;
 }
 
 EXPORT_SYMBOL_GPL(lockdep_init_map);
@@ -1948,8 +1950,8 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
                           unsigned long ip)
 {
         struct task_struct *curr = current;
+        struct lock_class *class = NULL;
         struct held_lock *hlock;
-        struct lock_class *class;
         unsigned int depth, id;
         int chain_head = 0;
         u64 chain_key;
@@ -1967,8 +1969,11 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
                 return 0;
         }
 
-        class = lock->class[subclass];
-        /* not cached yet? */
+        if (!subclass)
+                class = lock->class_cache;
+        /*
+         * Not cached yet or subclass?
+         */
         if (unlikely(!class)) {
                 class = register_lock_class(lock, subclass);
                 if (!class)
@@ -2469,48 +2474,44 @@ void lockdep_free_key_range(void *start, unsigned long size)
 
 void lockdep_reset_lock(struct lockdep_map *lock)
 {
-        struct lock_class *class, *next, *entry;
+        struct lock_class *class, *next;
         struct list_head *head;
         unsigned long flags;
         int i, j;
 
         raw_local_irq_save(flags);
-        __raw_spin_lock(&hash_lock);
 
         /*
-         * Remove all classes this lock has:
+         * Remove all classes this lock might have:
+         */
+        for (j = 0; j < MAX_LOCKDEP_SUBCLASSES; j++) {
+                /*
+                 * If the class exists we look it up and zap it:
+                 */
+                class = look_up_lock_class(lock, j);
+                if (class)
+                        zap_class(class);
+        }
+        /*
+         * Debug check: in the end all mapped classes should
+         * be gone.
          */
+        __raw_spin_lock(&hash_lock);
         for (i = 0; i < CLASSHASH_SIZE; i++) {
                 head = classhash_table + i;
                 if (list_empty(head))
                         continue;
                 list_for_each_entry_safe(class, next, head, hash_entry) {
-                        for (j = 0; j < MAX_LOCKDEP_SUBCLASSES; j++) {
-                                entry = lock->class[j];
-                                if (class == entry) {
-                                        zap_class(class);
-                                        lock->class[j] = NULL;
-                                        break;
-                                }
+                        if (unlikely(class == lock->class_cache)) {
+                                __raw_spin_unlock(&hash_lock);
+                                DEBUG_LOCKS_WARN_ON(1);
+                                goto out_restore;
                         }
                 }
         }
-
-        /*
-         * Debug check: in the end all mapped classes should
-         * be gone.
-         */
-        for (j = 0; j < MAX_LOCKDEP_SUBCLASSES; j++) {
-                entry = lock->class[j];
-                if (!entry)
-                        continue;
-                __raw_spin_unlock(&hash_lock);
-                DEBUG_LOCKS_WARN_ON(1);
-                raw_local_irq_restore(flags);
-                return;
-        }
-
         __raw_spin_unlock(&hash_lock);
+
+out_restore:
         raw_local_irq_restore(flags);
 }
 
@@ -2571,7 +2572,7 @@ static inline int in_range(const void *start, const void *addr, const void *end)
 
 static void
 print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
-                     const void *mem_to)
+                     const void *mem_to, struct held_lock *hlock)
 {
         if (!debug_locks_off())
                 return;
@@ -2583,6 +2584,7 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
         printk(  "-------------------------\n");
         printk("%s/%d is freeing memory %p-%p, with a lock still held there!\n",
                 curr->comm, curr->pid, mem_from, mem_to-1);
+        print_lock(hlock);
         lockdep_print_held_locks(curr);
 
         printk("\nstack backtrace:\n");
@@ -2616,7 +2618,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
                                         !in_range(mem_from, lock_to, mem_to))
                         continue;
 
-                print_freed_lock_bug(curr, mem_from, mem_to);
+                print_freed_lock_bug(curr, mem_from, mem_to, hlock);
                 break;
         }
         local_irq_restore(flags);