ceph: fix a wrong comparison

[cascardo/linux.git] / fs / eventpoll.c

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index ae1dbcf..8a74a2a 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -94,6 +94,11 @@
 /* Epoll private bits inside the event mask */
 #define EP_PRIVATE_BITS (EPOLLWAKEUP | EPOLLONESHOT | EPOLLET | EPOLLEXCLUSIVE)
 
+#define EPOLLINOUT_BITS (POLLIN | POLLOUT)
+
+#define EPOLLEXCLUSIVE_OK_BITS (EPOLLINOUT_BITS | POLLERR | POLLHUP | \
+                               EPOLLWAKEUP | EPOLLET | EPOLLEXCLUSIVE)
+
 /* Maximum number of nesting allowed inside epoll sets */
 #define EP_MAX_NESTS 4
 
@@ -1068,7 +1073,22 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k
         * wait list.
         */
        if (waitqueue_active(&ep->wq)) {
-               ewake = 1;
+               if ((epi->event.events & EPOLLEXCLUSIVE) &&
+                                       !((unsigned long)key & POLLFREE)) {
+                       switch ((unsigned long)key & EPOLLINOUT_BITS) {
+                       case POLLIN:
+                               if (epi->event.events & POLLIN)
+                                       ewake = 1;
+                               break;
+                       case POLLOUT:
+                               if (epi->event.events & POLLOUT)
+                                       ewake = 1;
+                               break;
+                       case 0:
+                               ewake = 1;
+                               break;
+                       }
+               }
                wake_up_locked(&ep->wq);
        }
        if (waitqueue_active(&ep->poll_wait))
@@ -1596,7 +1616,7 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
 {
        int res = 0, eavail, timed_out = 0;
        unsigned long flags;
-       long slack = 0;
+       u64 slack = 0;
        wait_queue_t wait;
        ktime_t expires, *to = NULL;
 
@@ -1875,9 +1895,13 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
         * 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;
+       if (epds.events & EPOLLEXCLUSIVE) {
+               if (op == EPOLL_CTL_MOD)
+                       goto error_tgt_fput;
+               if (op == EPOLL_CTL_ADD && (is_file_epoll(tf.file) ||
+                               (epds.events & ~EPOLLEXCLUSIVE_OK_BITS)))
+                       goto error_tgt_fput;
+       }
 
        /*
         * At this point it is safe to assume that the "private_data" contains
@@ -1950,8 +1974,10 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
                break;
        case EPOLL_CTL_MOD:
                if (epi) {
-                       epds.events |= POLLERR | POLLHUP;
-                       error = ep_modify(ep, epi, &epds);
+                       if (!(epi->event.events & EPOLLEXCLUSIVE)) {
+                               epds.events |= POLLERR | POLLHUP;
+                               error = ep_modify(ep, epi, &epds);
+                       }
                } else
                        error = -ENOENT;
                break;