---

yaml
---
r: 178751
b: refs/heads/master
c: 846f997
h: refs/heads/master
i:
  178749: 98a085c
  178747: 72f20aa
  178743: 6a403c0
  178735: 58620f7
  178719: 87b180c
  178687: 59a534c
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3e27249c84beed1c79d767b350e52ad038db9053
+refs/heads/master: 846f99749ab68bbc7f75c74fec305de675b1a1bf

trunk/fs/sysfs/dir.c

@@ -106,8 +106,10 @@ static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
 			return NULL;
 
 		t = atomic_cmpxchg(&sd->s_active, v, v + 1);
-		if (likely(t == v))
+		if (likely(t == v)) {
+			rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
 			return sd;
+		}
 		if (t < 0)
 			return NULL;
 
@@ -130,6 +132,7 @@ static void sysfs_put_active(struct sysfs_dirent *sd)
 	if (unlikely(!sd))
 		return;
 
+	rwsem_release(&sd->dep_map, 1, _RET_IP_);
 	v = atomic_dec_return(&sd->s_active);
 	if (likely(v != SD_DEACTIVATED_BIAS))
 		return;
@@ -194,15 +197,21 @@ static void sysfs_deactivate(struct sysfs_dirent *sd)
 	BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED));
 	sd->s_sibling = (void *)&wait;
 
+	rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_);
 	/* atomic_add_return() is a mb(), put_active() will always see
 	 * the updated sd->s_sibling.
 	 */
 	v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
 
-	if (v != SD_DEACTIVATED_BIAS)
+	if (v != SD_DEACTIVATED_BIAS) {
+		lock_contended(&sd->dep_map, _RET_IP_);
 		wait_for_completion(&wait);
+	}
 
 	sd->s_sibling = NULL;
+
+	lock_acquired(&sd->dep_map, _RET_IP_);
+	rwsem_release(&sd->dep_map, 1, _RET_IP_);
 }
 
 static int sysfs_alloc_ino(ino_t *pino)
@@ -345,6 +354,7 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
 
 	atomic_set(&sd->s_count, 1);
 	atomic_set(&sd->s_active, 0);
+	sysfs_dirent_init_lockdep(sd);
 
 	sd->s_name = name;
 	sd->s_mode = mode;

trunk/fs/sysfs/sysfs.h

@@ -8,6 +8,7 @@
  * This file is released under the GPLv2.
  */
 
+#include <linux/lockdep.h>
 #include <linux/fs.h>
 
 struct sysfs_open_dirent;
@@ -50,6 +51,9 @@ struct sysfs_inode_attrs {
 struct sysfs_dirent {
 	atomic_t		s_count;
 	atomic_t		s_active;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	dep_map;
+#endif
 	struct sysfs_dirent	*s_parent;
 	struct sysfs_dirent	*s_sibling;
 	const char		*s_name;
@@ -84,6 +88,17 @@ static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
 	return sd->s_flags & SYSFS_TYPE_MASK;
 }
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+#define sysfs_dirent_init_lockdep(sd)				\
+do {								\
+	static struct lock_class_key __key;			\
+								\
+	lockdep_init_map(&sd->dep_map, "s_active", &__key, 0);	\
+} while(0)
+#else
+#define sysfs_dirent_init_lockdep(sd) do {} while(0)
+#endif
+
 /*
  * Context structure to be used while adding/removing nodes.
  */