fsnotify: fsnotify_add_notify_event should return an event

[firefly-linux-kernel-4.4.55.git] / fs / notify / notification.c

diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index e6dde25fb99bace89ece70092a8a9aad7fe6a45e..f39260f8f8656e42feac01e728497cd05650d881 100644 (file)
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -137,16 +137,14 @@ struct fsnotify_event_private_data *fsnotify_remove_priv_from_event(struct fsnot
  * 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.
  */
-int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event,
-                             struct fsnotify_event_private_data *priv,
-                             int (*merge)(struct list_head *,
-                                          struct fsnotify_event *,
-                                          void **arg),
-                             void **arg)
+struct fsnotify_event *fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event,
+                                                struct fsnotify_event_private_data *priv,
+                                                struct fsnotify_event *(*merge)(struct list_head *,
+                                                                                struct fsnotify_event *))
 {
+       struct fsnotify_event *return_event = NULL;
        struct fsnotify_event_holder *holder = NULL;
        struct list_head *list = &group->notification_list;
-       int rc = 0;
 
        pr_debug("%s: group=%p event=%p priv=%p\n", __func__, group, event, priv);
 
@@ -162,27 +160,37 @@ int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_even
 alloc_holder:
                holder = fsnotify_alloc_event_holder();
                if (!holder)
-                       return -ENOMEM;
+                       return ERR_PTR(-ENOMEM);
        }
 
        mutex_lock(&group->notification_mutex);
 
        if (group->q_len >= group->max_events) {
                event = q_overflow_event;
-               rc = -EOVERFLOW;
+
+               /*
+                * we need to return the overflow event
+                * which means we need a ref
+                */
+               fsnotify_get_event(event);
+               return_event = event;
+
                /* sorry, no private data on the overflow event */
                priv = NULL;
        }
 
        if (!list_empty(list) && merge) {
-               int ret;
+               struct fsnotify_event *tmp;
 
-               ret = merge(list, event, arg);
-               if (ret) {
+               tmp = merge(list, event);
+               if (tmp) {
                        mutex_unlock(&group->notification_mutex);
+
+                       if (return_event)
+                               fsnotify_put_event(return_event);
                        if (holder != &event->holder)
                                fsnotify_destroy_event_holder(holder);
-                       return ret;
+                       return tmp;
                }
        }
 
@@ -197,6 +205,12 @@ alloc_holder:
                 * event holder was used, go back and get a new one */
                spin_unlock(&event->lock);
                mutex_unlock(&group->notification_mutex);
+
+               if (return_event) {
+                       fsnotify_put_event(return_event);
+                       return_event = NULL;
+               }
+
                goto alloc_holder;
        }
 
@@ -211,7 +225,7 @@ alloc_holder:
        mutex_unlock(&group->notification_mutex);
 
        wake_up(&group->notification_waitq);
-       return rc;
+       return return_event;
 }
 
 /*