linux-master/fs/eventpoll.c

48  * 2) ep->mtx (mutex)
59  * mutex (ep->mtx). It is acquired during the event transfer loop,
68  * It is necessary to acquire multiple "ep->mtx"es at once in the
71  * epoll_ctl(e1, EPOLL_CTL_ADD, e2), e1->mtx will always be acquired
72  * before e2->mtx). Since we disallow cycles of epoll file
77  * It is possible to drop the "ep->mtx" and to use the global
79  * but having "ep->mtx" will make the interface more scalable.
81  * normal operations the epoll private "ep->mtx" will guarantee
186 	struct mutex mtx;
653  * descriptor.  Must be called with "mtx" held.
667 /* call only when ep->mtx is held */
670 	return rcu_dereference_check(epi->ws, lockdep_is_held(&epi->ep->mtx));
673 /* call only when ep->mtx is held */
687 /* call when ep->mtx cannot be held (ep_poll_callback) */
789 	mutex_destroy(&ep->mtx);
797  * all the associated resources. Must be called with "mtx" held.
850 	 * ep->mtx. The rcu read side, reverse_path_check_proc(), does not make
877 	mutex_lock(&ep->mtx);
905 	mutex_unlock(&ep->mtx);
961 	mutex_lock_nested(&ep->mtx, depth);
978 	mutex_unlock(&ep->mtx);
984  * the ep->mtx so we need to start from depth=1, such that mutex_lock_nested()
1012 	mutex_lock(&ep->mtx);
1026 	mutex_unlock(&ep->mtx);
1056 	 * the ep->mtx.
1070 		mutex_lock(&ep->mtx);
1072 		mutex_unlock(&ep->mtx);
1089 	mutex_init(&ep->mtx);
1106  * are protected by the "mtx" mutex, and ep_find() must be called with
1107  * "mtx" held.
1165 	mutex_lock(&ep->mtx);
1171 	mutex_unlock(&ep->mtx);
1580  * Must be called with "mtx" held.
1614 		mutex_lock_nested(&tep->mtx, 1);
1618 			mutex_unlock(&tep->mtx);
1629 	 * protected by "mtx", and ep_insert() is called with "mtx" held.
1633 		mutex_unlock(&tep->mtx);
1707  * has a match in the current file status. Must be called with "mtx" held.
1725 	epi->event.data = event->data; /* protected by mtx */
1799 	mutex_lock(&ep->mtx);
1804 	 * Items cannot vanish during the loop we are holding ep->mtx.
1833 		 * deliver the event to userspace. Again, we are holding ep->mtx,
1860 			 * ep_send_events() holding "mtx" and the
1868 	mutex_unlock(&ep->mtx);
2072 	mutex_lock_nested(&ep->mtx, depth + 1);
2099 	mutex_unlock(&ep->mtx);
2293 	error = epoll_mutex_lock(&ep->mtx, 0, nonblock);
2299 			mutex_unlock(&ep->mtx);
2311 			error = epoll_mutex_lock(&ep->mtx, 0, nonblock);
2318 	 * Try to lookup the file inside our RB tree. Since we grabbed "mtx"
2355 	mutex_unlock(&ep->mtx);