fs/notify/group.c

20  * Final freeing of a group
22 static void fsnotify_final_destroy_group(struct fsnotify_group *group)
24 	if (group->ops->free_group_priv)
25 		group->ops->free_group_priv(group);
27 	mem_cgroup_put(group->memcg);
28 	mutex_destroy(&group->mark_mutex);
30 	kfree(group);
34  * Stop queueing new events for this group. Once this function returns
35  * fsnotify_add_event() will not add any new events to the group's queue.
37 void fsnotify_group_stop_queueing(struct fsnotify_group *group)
39 	spin_lock(&group->notification_lock);
40 	group->shutdown = true;
41 	spin_unlock(&group->notification_lock);
45  * Trying to get rid of a group. Remove all marks, flush all events and release
46  * the group reference.
48  * hold a ref to the group.
50 void fsnotify_destroy_group(struct fsnotify_group *group)
58 	fsnotify_group_stop_queueing(group);
60 	/* Clear all marks for this group and queue them for destruction */
61 	fsnotify_clear_marks_by_group(group, FSNOTIFY_OBJ_TYPE_ANY);
68 	wait_event(group->notification_waitq, !atomic_read(&group->user_waits));
81 	 * notification against this group. So clearing the notification queue
84 	fsnotify_flush_notify(group);
90 	if (group->overflow_event)
91 		group->ops->free_event(group, group->overflow_event);
93 	fsnotify_put_group(group);
97  * Get reference to a group.
99 void fsnotify_get_group(struct fsnotify_group *group)
101 	refcount_inc(&group->refcnt);
105  * Drop a reference to a group.  Free it if it's through.
107 void fsnotify_put_group(struct fsnotify_group *group)
109 	if (refcount_dec_and_test(&group->refcnt))
110 		fsnotify_final_destroy_group(group);
119 	struct fsnotify_group *group;
121 	group = kzalloc(sizeof(struct fsnotify_group), gfp);
122 	if (!group)
125 	/* set to 0 when there a no external references to this group */
126 	refcount_set(&group->refcnt, 1);
127 	atomic_set(&group->user_waits, 0);
129 	spin_lock_init(&group->notification_lock);
130 	INIT_LIST_HEAD(&group->notification_list);
131 	init_waitqueue_head(&group->notification_waitq);
132 	group->max_events = UINT_MAX;
134 	mutex_init(&group->mark_mutex);
135 	INIT_LIST_HEAD(&group->marks_list);
137 	group->ops = ops;
138 	group->flags = flags;
148 		lockdep_set_class(&group->mark_mutex, &nofs_marks_lock);
150 	return group;
154  * Create a new fsnotify_group and hold a reference for the group returned.
168 	struct fsnotify_group *group = file->private_data;
170 	return fasync_helper(fd, file, on, &group->fsn_fa) >= 0 ? 0 : -EIO;