1 files changed, 26 insertions, 5 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 24fa995f0312..e6bb9b2a4cbe 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -132,6 +132,24 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
         rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children);
 }
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+
+/* Test for attributes that want to ignore lockdep for read-locking */
+static bool ignore_lockdep(struct sysfs_dirent *sd)
+{
+        return sysfs_type(sd) == SYSFS_KOBJ_ATTR &&
+                        sd->s_attr.attr->ignore_lockdep;
+}
+
+#else
+
+static inline bool ignore_lockdep(struct sysfs_dirent *sd)
+{
+        return true;
+}
+
+#endif
+
 /**
  *      sysfs_get_active - get an active reference to sysfs_dirent
  *      @sd: sysfs_dirent to get an active reference to
@@ -155,15 +173,17 @@ 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)) {
-                        rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
-                        return sd;
-                }
+                if (likely(t == v))
+                        break;
                 if (t < 0)
                         return NULL;
 
                 cpu_relax();
         }
+
+        if (likely(!ignore_lockdep(sd)))
+                rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
+        return sd;
 }
 
 /**
@@ -180,7 +200,8 @@ void sysfs_put_active(struct sysfs_dirent *sd)
         if (unlikely(!sd))
                 return;
 
-        rwsem_release(&sd->dep_map, 1, _RET_IP_);
+        if (likely(!ignore_lockdep(sd)))
+                rwsem_release(&sd->dep_map, 1, _RET_IP_);
         v = atomic_dec_return(&sd->s_active);
         if (likely(v != SD_DEACTIVATED_BIAS))
                 return;