1 files changed, 25 insertions, 15 deletions

diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 952237b8e2d..1e58402171a 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -79,15 +79,16 @@ void fsnotify_destroy_event(struct fsnotify_group *group,
 
 /*
  * Add an event to the group notification queue.  The group can later pull this
- * event off the queue to deal with.  If the event is successfully added to the
- * group's notification queue, a reference is taken on event.
+ * event off the queue to deal with.  The function returns 0 if the event was
+ * added to the queue, 1 if the event was merged with some other queued event,
+ * 2 if the queue of events has overflown.
  */
-struct fsnotify_event *fsnotify_add_notify_event(struct fsnotify_group *group,
-						 struct fsnotify_event *event,
-						 struct fsnotify_event *(*merge)(struct list_head *,
-										 struct fsnotify_event *))
+int fsnotify_add_notify_event(struct fsnotify_group *group,
+			      struct fsnotify_event *event,
+			      int (*merge)(struct list_head *,
+					   struct fsnotify_event *))
 {
-	struct fsnotify_event *return_event = NULL;
+	int ret = 0;
 	struct list_head *list = &group->notification_list;
 
 	pr_debug("%s: group=%p event=%p\n", __func__, group, event);
@@ -95,27 +96,32 @@ struct fsnotify_event *fsnotify_add_notify_event(struct fsnotify_group *group,
 	mutex_lock(&group->notification_mutex);
 
 	if (group->q_len >= group->max_events) {
+		ret = 2;
 		/* Queue overflow event only if it isn't already queued */
-		if (list_empty(&group->overflow_event.list))
-			event = &group->overflow_event;
-		return_event = event;
+		if (!list_empty(&group->overflow_event->list)) {
+			mutex_unlock(&group->notification_mutex);
+			return ret;
+		}
+		event = group->overflow_event;
+		goto queue;
 	}
 
 	if (!list_empty(list) && merge) {
-		return_event = merge(list, event);
-		if (return_event) {
+		ret = merge(list, event);
+		if (ret) {
 			mutex_unlock(&group->notification_mutex);
-			return return_event;
+			return ret;
 		}
 	}
 
+queue:
 	group->q_len++;
 	list_add_tail(&event->list, list);
 	mutex_unlock(&group->notification_mutex);
 
 	wake_up(&group->notification_waitq);
 	kill_fasync(&group->fsn_fa, SIGIO, POLL_IN);
-	return return_event;
+	return ret;
 }
 
 /*
@@ -132,7 +138,11 @@ struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group
 
 	event = list_first_entry(&group->notification_list,
 				 struct fsnotify_event, list);
-	list_del(&event->list);
+	/*
+	 * We need to init list head for the case of overflow event so that
+	 * check in fsnotify_add_notify_events() works
+	 */
+	list_del_init(&event->list);
 	group->q_len--;
 
 	return event;