diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/eventpoll.c | 73 |
1 files changed, 37 insertions, 36 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c index be50799737f4..aaf614ee08e4 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1624,21 +1624,22 @@ static __poll_t ep_send_events_proc(struct eventpoll *ep, struct list_head *head { struct ep_send_events_data *esed = priv; __poll_t revents; - struct epitem *epi; - struct epoll_event __user *uevent; + struct epitem *epi, *tmp; + struct epoll_event __user *uevent = esed->events; struct wakeup_source *ws; poll_table pt; init_poll_funcptr(&pt, NULL); + esed->res = 0; /* * We can loop without lock because we are passed a task private list. * Items cannot vanish during the loop because ep_scan_ready_list() is * holding "mtx" during this call. */ - for (esed->res = 0, uevent = esed->events; - !list_empty(head) && esed->res < esed->maxevents;) { - epi = list_first_entry(head, struct epitem, rdllink); + list_for_each_entry_safe(epi, tmp, head, rdllink) { + if (esed->res >= esed->maxevents) + break; /* * Activate ep->ws before deactivating epi->ws to prevent @@ -1658,42 +1659,42 @@ static __poll_t ep_send_events_proc(struct eventpoll *ep, struct list_head *head list_del_init(&epi->rdllink); - revents = ep_item_poll(epi, &pt, 1); - /* * If the event mask intersect the caller-requested one, * deliver the event to userspace. Again, ep_scan_ready_list() - * is holding "mtx", so no operations coming from userspace + * is holding ep->mtx, so no operations coming from userspace * can change the item. */ - if (revents) { - if (__put_user(revents, &uevent->events) || - __put_user(epi->event.data, &uevent->data)) { - list_add(&epi->rdllink, head); - ep_pm_stay_awake(epi); - if (!esed->res) - esed->res = -EFAULT; - return 0; - } - esed->res++; - uevent++; - if (epi->event.events & EPOLLONESHOT) - epi->event.events &= EP_PRIVATE_BITS; - else if (!(epi->event.events & EPOLLET)) { - /* - * If this file has been added with Level - * Trigger mode, we need to insert back inside - * the ready list, so that the next call to - * epoll_wait() will check again the events - * availability. At this point, no one can insert - * into ep->rdllist besides us. The epoll_ctl() - * callers are locked out by - * ep_scan_ready_list() holding "mtx" and the - * poll callback will queue them in ep->ovflist. - */ - list_add_tail(&epi->rdllink, &ep->rdllist); - ep_pm_stay_awake(epi); - } + revents = ep_item_poll(epi, &pt, 1); + if (!revents) + continue; + + if (__put_user(revents, &uevent->events) || + __put_user(epi->event.data, &uevent->data)) { + list_add(&epi->rdllink, head); + ep_pm_stay_awake(epi); + if (!esed->res) + esed->res = -EFAULT; + return 0; + } + esed->res++; + uevent++; + if (epi->event.events & EPOLLONESHOT) + epi->event.events &= EP_PRIVATE_BITS; + else if (!(epi->event.events & EPOLLET)) { + /* + * If this file has been added with Level + * Trigger mode, we need to insert back inside + * the ready list, so that the next call to + * epoll_wait() will check again the events + * availability. At this point, no one can insert + * into ep->rdllist besides us. The epoll_ctl() + * callers are locked out by + * ep_scan_ready_list() holding "mtx" and the + * poll callback will queue them in ep->ovflist. + */ + list_add_tail(&epi->rdllink, &ep->rdllist); + ep_pm_stay_awake(epi); } } |