Linux 3.14

[~andy/linux] / fs / notify / notification.c

diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 18b3c4427dcac0f2c9125581cc171be3f1eb3a9f..1e58402171a56cd9d078ab62307951689a5630df 100644 (file)
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -80,7 +80,8 @@ 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.  The function returns 0 if the event was
- * added to the queue, 1 if the event was merged with some other queued event.
+ * added to the queue, 1 if the event was merged with some other queued event,
+ * 2 if the queue of events has overflown.
  */
 int fsnotify_add_notify_event(struct fsnotify_group *group,
                              struct fsnotify_event *event,
@@ -95,10 +96,14 @@ int 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;
-               ret = 1;
+               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) {
@@ -109,6 +114,7 @@ int fsnotify_add_notify_event(struct fsnotify_group *group,
                }
        }
 
+queue:
        group->q_len++;
        list_add_tail(&event->list, list);
        mutex_unlock(&group->notification_mutex);
@@ -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;