diff options
Diffstat (limited to 'fs/notify/notification.c')
| -rw-r--r-- | fs/notify/notification.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/fs/notify/notification.c b/fs/notify/notification.c index 8a7a8cd041e8..1a8010e7a2a0 100644 --- a/fs/notify/notification.c +++ b/fs/notify/notification.c @@ -74,8 +74,17 @@ void fsnotify_destroy_event(struct fsnotify_group *group, /* Overflow events are per-group and we don't want to free them */ if (!event || event->mask == FS_Q_OVERFLOW) return; - /* If the event is still queued, we have a problem... */ - WARN_ON(!list_empty(&event->list)); + /* + * If the event is still queued, we have a problem... Do an unreliable + * lockless check first to avoid locking in the common case. The + * locking may be necessary for permission events which got removed + * from the list by a different CPU than the one freeing the event. + */ + if (!list_empty(&event->list)) { + spin_lock(&group->notification_lock); + WARN_ON(!list_empty(&event->list)); + spin_unlock(&group->notification_lock); + } group->ops->free_event(event); } |