20  * Basic idea behind the notification queue: An fsnotify group (like inotify)
23  * event to the group notify queue.  Since a single event might need to be on
24  * multiple group's notification queues we can't add the event directly to each
30  * another group a new event_holder (from fsnotify_event_holder_cachep) will be
64 bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group)  in fsnotify_notify_queue_is_empty()  argument
66 	assert_spin_locked(&group->notification_lock);  in fsnotify_notify_queue_is_empty()
67 	return list_empty(&group->notification_list) ? true : false;  in fsnotify_notify_queue_is_empty()
70 void fsnotify_destroy_event(struct fsnotify_group *group,  in fsnotify_destroy_event()  argument
73 	/* Overflow events are per-group and we don't want to free them */  in fsnotify_destroy_event()
83 		spin_lock(&group->notification_lock);  in fsnotify_destroy_event()
85 		spin_unlock(&group->notification_lock);  in fsnotify_destroy_event()
87 	group->ops->free_event(event);  in fsnotify_destroy_event()
91  * Add an event to the group notification queue.  The group can later pull this
95  * or the group is shutting down.
97 int fsnotify_add_event(struct fsnotify_group *group,  in fsnotify_add_event()  argument
103 	struct list_head *list = &group->notification_list;  in fsnotify_add_event()
105 	pr_debug("%s: group=%p event=%p\n", __func__, group, event);  in fsnotify_add_event()
107 	spin_lock(&group->notification_lock);  in fsnotify_add_event()
109 	if (group->shutdown) {  in fsnotify_add_event()
110 		spin_unlock(&group->notification_lock);  in fsnotify_add_event()
114 	if (event == group->overflow_event ||  in fsnotify_add_event()
115 	    group->q_len >= group->max_events) {  in fsnotify_add_event()
118 		if (!list_empty(&group->overflow_event->list)) {  in fsnotify_add_event()
119 			spin_unlock(&group->notification_lock);  in fsnotify_add_event()
122 		event = group->overflow_event;  in fsnotify_add_event()
129 			spin_unlock(&group->notification_lock);  in fsnotify_add_event()
135 	group->q_len++;  in fsnotify_add_event()
137 	spin_unlock(&group->notification_lock);  in fsnotify_add_event()
139 	wake_up(&group->notification_waitq);  in fsnotify_add_event()
140 	kill_fasync(&group->fsn_fa, SIGIO, POLL_IN);  in fsnotify_add_event()
148 struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group)  in fsnotify_remove_first_event()  argument
152 	assert_spin_locked(&group->notification_lock);  in fsnotify_remove_first_event()
154 	pr_debug("%s: group=%p\n", __func__, group);  in fsnotify_remove_first_event()
156 	event = list_first_entry(&group->notification_list,  in fsnotify_remove_first_event()
163 	group->q_len--;  in fsnotify_remove_first_event()
172 struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group)  in fsnotify_peek_first_event()  argument
174 	assert_spin_locked(&group->notification_lock);  in fsnotify_peek_first_event()
176 	return list_first_entry(&group->notification_list,  in fsnotify_peek_first_event()
181  * Called when a group is being torn down to clean up any outstanding
184 void fsnotify_flush_notify(struct fsnotify_group *group)  in fsnotify_flush_notify()  argument
188 	spin_lock(&group->notification_lock);  in fsnotify_flush_notify()
189 	while (!fsnotify_notify_queue_is_empty(group)) {  in fsnotify_flush_notify()
190 		event = fsnotify_remove_first_event(group);  in fsnotify_flush_notify()
191 		spin_unlock(&group->notification_lock);  in fsnotify_flush_notify()
192 		fsnotify_destroy_event(group, event);  in fsnotify_flush_notify()
193 		spin_lock(&group->notification_lock);  in fsnotify_flush_notify()
195 	spin_unlock(&group->notification_lock);  in fsnotify_flush_notify()
200  * group's handle_event function if the group was interested in this