diff options
Diffstat (limited to 'fs/eventpoll.c')
| -rw-r--r-- | fs/eventpoll.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 1e009cad8d5c..ae1dbcf47e97 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -92,7 +92,7 @@ */ /* Epoll private bits inside the event mask */ -#define EP_PRIVATE_BITS (EPOLLWAKEUP | EPOLLONESHOT | EPOLLET) +#define EP_PRIVATE_BITS (EPOLLWAKEUP | EPOLLONESHOT | EPOLLET | EPOLLEXCLUSIVE) /* Maximum number of nesting allowed inside epoll sets */ #define EP_MAX_NESTS 4 @@ -1002,6 +1002,7 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k unsigned long flags; struct epitem *epi = ep_item_from_wait(wait); struct eventpoll *ep = epi->ep; + int ewake = 0; if ((unsigned long)key & POLLFREE) { ep_pwq_from_wait(wait)->whead = NULL; @@ -1066,8 +1067,10 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k * Wake up ( if active ) both the eventpoll wait list and the ->poll() * wait list. */ - if (waitqueue_active(&ep->wq)) + if (waitqueue_active(&ep->wq)) { + ewake = 1; wake_up_locked(&ep->wq); + } if (waitqueue_active(&ep->poll_wait)) pwake++; @@ -1078,6 +1081,9 @@ out_unlock: if (pwake) ep_poll_safewake(&ep->poll_wait); + if (epi->event.events & EPOLLEXCLUSIVE) + return ewake; + return 1; } @@ -1095,7 +1101,10 @@ static void ep_ptable_queue_proc(struct file *file, wait_queue_head_t *whead, init_waitqueue_func_entry(&pwq->wait, ep_poll_callback); pwq->whead = whead; pwq->base = epi; - add_wait_queue(whead, &pwq->wait); + if (epi->event.events & EPOLLEXCLUSIVE) + add_wait_queue_exclusive(whead, &pwq->wait); + else + add_wait_queue(whead, &pwq->wait); list_add_tail(&pwq->llink, &epi->pwqlist); epi->nwait++; } else { @@ -1862,6 +1871,15 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd, goto error_tgt_fput; /* + * epoll adds to the wakeup queue at EPOLL_CTL_ADD time only, + * so EPOLLEXCLUSIVE is not allowed for a EPOLL_CTL_MOD operation. + * Also, we do not currently supported nested exclusive wakeups. + */ + if ((epds.events & EPOLLEXCLUSIVE) && (op == EPOLL_CTL_MOD || + (op == EPOLL_CTL_ADD && is_file_epoll(tf.file)))) + goto error_tgt_fput; + + /* * At this point it is safe to assume that the "private_data" contains * our own data structure. */ |