fsnotify: add a way to stop queueing events on group shutdown

[cascardo/linux.git] / fs / notify / group.c

diff --git a/fs/notify/group.c b/fs/notify/group.c
index 3e2dd85..b47f7cf 100644 (file)
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -39,6 +39,17 @@ static void fsnotify_final_destroy_group(struct fsnotify_group *group)
        kfree(group);
 }
 
+/*
+ * Stop queueing new events for this group. Once this function returns
+ * fsnotify_add_event() will not add any new events to the group's queue.
+ */
+void fsnotify_group_stop_queueing(struct fsnotify_group *group)
+{
+       mutex_lock(&group->notification_mutex);
+       group->shutdown = true;
+       mutex_unlock(&group->notification_mutex);
+}
+
 /*
  * Trying to get rid of a group. Remove all marks, flush all events and release
  * the group reference.
@@ -47,6 +58,14 @@ static void fsnotify_final_destroy_group(struct fsnotify_group *group)
  */
 void fsnotify_destroy_group(struct fsnotify_group *group)
 {
+       /*
+        * Stop queueing new events. The code below is careful enough to not
+        * require this but fanotify needs to stop queuing events even before
+        * fsnotify_destroy_group() is called and this makes the other callers
+        * of fsnotify_destroy_group() to see the same behavior.
+        */
+       fsnotify_group_stop_queueing(group);
+
        /* clear all inode marks for this group, attach them to destroy_list */
        fsnotify_detach_group_marks(group);