Commit e3e096e7 authored by Al Viro's avatar Al Viro
Browse files

ep_insert(): don't open-code ep_remove() on failure exits 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 57804b1c

fs/eventpoll.c

+14 −37
Original line number Diff line number Diff line
@@ -1384,12 +1384,16 @@ static int ep_insert(struct eventpoll *ep, const struct epoll_event *event, 
	epi->next = EP_UNACTIVE_PTR;

	if (epi->event.events & EPOLLWAKEUP) {

		error = ep_create_wakeup_source(epi);

		if (error)

			goto error_create_wakeup_source;

		if (error) {

			kmem_cache_free(epi_cache, epi);

			return error;

		}

	} else {

		RCU_INIT_POINTER(epi->ws, NULL);

	}



	atomic_long_inc(&ep->user->epoll_watches);



	/* Add the current item to the list of active epoll hook for this file */

	spin_lock(&tfile->f_lock);

	list_add_tail_rcu(&epi->fllink, &tfile->f_ep_links);
@@ -1402,9 +1406,10 @@ static int ep_insert(struct eventpoll *ep, const struct epoll_event *event, 
	ep_rbtree_insert(ep, epi);



	/* now check if we've created too many backpaths */

	error = -EINVAL;

	if (full_check && reverse_path_check())

		goto error_remove_epi;

	if (unlikely(full_check && reverse_path_check())) {

		ep_remove(ep, epi);

		return -EINVAL;

	}



	/* Initialize the poll table using the queue callback */

	epq.epi = epi;
@@ -1424,9 +1429,10 @@ static int ep_insert(struct eventpoll *ep, const struct epoll_event *event, 
	 * install process. Namely an allocation for a wait queue failed due

	 * high memory pressure.

	 */

	error = -ENOMEM;

	if (!epq.epi)

		goto error_unregister;

	if (unlikely(!epq.epi)) {

		ep_remove(ep, epi);

		return -ENOMEM;

	}



	/* We have to drop the new item inside our item list to keep track of it */

	write_lock_irq(&ep->lock);
@@ -1448,40 +1454,11 @@ static int ep_insert(struct eventpoll *ep, const struct epoll_event *event, 


	write_unlock_irq(&ep->lock);



	atomic_long_inc(&ep->user->epoll_watches);



	/* We have to call this outside the lock */

	if (pwake)

		ep_poll_safewake(ep, NULL);



	return 0;



error_unregister:

	ep_unregister_pollwait(ep, epi);

error_remove_epi:

	spin_lock(&tfile->f_lock);

	list_del_rcu(&epi->fllink);

	spin_unlock(&tfile->f_lock);



	rb_erase_cached(&epi->rbn, &ep->rbr);



	/*

	 * We need to do this because an event could have been arrived on some

	 * allocated wait queue. Note that we don't care about the ep->ovflist

	 * list, since that is used/cleaned only inside a section bound by "mtx".

	 * And ep_insert() is called with "mtx" held.

	 */

	write_lock_irq(&ep->lock);

	if (ep_is_linked(epi))

		list_del_init(&epi->rdllink);

	write_unlock_irq(&ep->lock);



	wakeup_source_unregister(ep_wakeup_source(epi));



error_create_wakeup_source:

	kmem_cache_free(epi_cache, epi);



	return error;

}



/*