7  * Basic idea behind the notification queue: An fsnotify group (like inotify)
10  * event to the group notify queue.  Since a single event might need to be on
11  * multiple group's notification queues we can't add the event directly to each
17  * another group a new event_holder (from fsnotify_event_holder_cachep) will be
51 bool fsnotify_notify_queue_is_empty(struct fsnotify_group *group)  in fsnotify_notify_queue_is_empty()  argument
53 	assert_spin_locked(&group->notification_lock);  in fsnotify_notify_queue_is_empty()
54 	return list_empty(&group->notification_list) ? true : false;  in fsnotify_notify_queue_is_empty()
57 void fsnotify_destroy_event(struct fsnotify_group *group,  in fsnotify_destroy_event()  argument
60 	/* Overflow events are per-group and we don't want to free them */  in fsnotify_destroy_event()
61 	if (!event || event == group->overflow_event)  in fsnotify_destroy_event()
70 		spin_lock(&group->notification_lock);  in fsnotify_destroy_event()
72 		spin_unlock(&group->notification_lock);  in fsnotify_destroy_event()
74 	group->ops->free_event(event);  in fsnotify_destroy_event()
78  * Add an event to the group notification queue.  The group can later pull this
82  * or the group is shutting down.
84 int fsnotify_add_event(struct fsnotify_group *group,  in fsnotify_add_event()  argument
90 	struct list_head *list = &group->notification_list;  in fsnotify_add_event()
92 	pr_debug("%s: group=%p event=%p\n", __func__, group, event);  in fsnotify_add_event()
94 	spin_lock(&group->notification_lock);  in fsnotify_add_event()
96 	if (group->shutdown) {  in fsnotify_add_event()
97 		spin_unlock(&group->notification_lock);  in fsnotify_add_event()
101 	if (event == group->overflow_event ||  in fsnotify_add_event()
102 	    group->q_len >= group->max_events) {  in fsnotify_add_event()
105 		if (!list_empty(&group->overflow_event->list)) {  in fsnotify_add_event()
106 			spin_unlock(&group->notification_lock);  in fsnotify_add_event()
109 		event = group->overflow_event;  in fsnotify_add_event()
116 			spin_unlock(&group->notification_lock);  in fsnotify_add_event()
122 	group->q_len++;  in fsnotify_add_event()
124 	spin_unlock(&group->notification_lock);  in fsnotify_add_event()
126 	wake_up(&group->notification_waitq);  in fsnotify_add_event()
127 	kill_fasync(&group->fsn_fa, SIGIO, POLL_IN);  in fsnotify_add_event()
131 void fsnotify_remove_queued_event(struct fsnotify_group *group,  in fsnotify_remove_queued_event()  argument
134 	assert_spin_locked(&group->notification_lock);  in fsnotify_remove_queued_event()
140 	group->q_len--;  in fsnotify_remove_queued_event()
147 struct fsnotify_event *fsnotify_remove_first_event(struct fsnotify_group *group)  in fsnotify_remove_first_event()  argument
151 	assert_spin_locked(&group->notification_lock);  in fsnotify_remove_first_event()
153 	pr_debug("%s: group=%p\n", __func__, group);  in fsnotify_remove_first_event()
155 	event = list_first_entry(&group->notification_list,  in fsnotify_remove_first_event()
157 	fsnotify_remove_queued_event(group, event);  in fsnotify_remove_first_event()
165 struct fsnotify_event *fsnotify_peek_first_event(struct fsnotify_group *group)  in fsnotify_peek_first_event()  argument
167 	assert_spin_locked(&group->notification_lock);  in fsnotify_peek_first_event()
169 	return list_first_entry(&group->notification_list,  in fsnotify_peek_first_event()
174  * Called when a group is being torn down to clean up any outstanding
177 void fsnotify_flush_notify(struct fsnotify_group *group)  in fsnotify_flush_notify()  argument
181 	spin_lock(&group->notification_lock);  in fsnotify_flush_notify()
182 	while (!fsnotify_notify_queue_is_empty(group)) {  in fsnotify_flush_notify()
183 		event = fsnotify_remove_first_event(group);  in fsnotify_flush_notify()
184 		spin_unlock(&group->notification_lock);  in fsnotify_flush_notify()
185 		fsnotify_destroy_event(group, event);  in fsnotify_flush_notify()
186 		spin_lock(&group->notification_lock);  in fsnotify_flush_notify()
188 	spin_unlock(&group->notification_lock);  in fsnotify_flush_notify()