From 8a43189a0d6bff3e8347e7fbe85336653655952a Mon Sep 17 00:00:00 2001
From: Davide Libenzi <davidel@xmailserver.org>
Date: Tue, 31 Mar 2009 15:24:22 -0700
Subject: [PATCH] --- yaml --- r: 139202 b: refs/heads/master c:
 2dfa4eeab0fc7e8633974f2770945311b31eedf6 h: refs/heads/master v: v3

---
 [refs]               |  2 +-
 trunk/fs/eventpoll.c | 31 +++++++++++++++++++++++++++++--
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 69ccacf5e218..54a6ea8353c0 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 37e5540b3c9d838eb20f2ca8ea2eb8072271e403
+refs/heads/master: 2dfa4eeab0fc7e8633974f2770945311b31eedf6
diff --git a/trunk/fs/eventpoll.c b/trunk/fs/eventpoll.c
index 336fdb8ed47b..a89f370fadb5 100644
--- a/trunk/fs/eventpoll.c
+++ b/trunk/fs/eventpoll.c
@@ -371,9 +371,28 @@ static int ep_call_nested(struct nested_calls *ncalls, int max_nests,
 	return error;
 }
 
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static inline void ep_wake_up_nested(wait_queue_head_t *wqueue,
+				     unsigned long events, int subclass)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave_nested(&wqueue->lock, flags, subclass);
+	wake_up_locked_poll(wqueue, events);
+	spin_unlock_irqrestore(&wqueue->lock, flags);
+}
+#else
+static inline void ep_wake_up_nested(wait_queue_head_t *wqueue,
+				     unsigned long events, int subclass)
+{
+	wake_up_poll(wqueue, events);
+}
+#endif
+
 static int ep_poll_wakeup_proc(void *priv, void *cookie, int call_nests)
 {
-	wake_up_nested((wait_queue_head_t *) cookie, 1 + call_nests);
+	ep_wake_up_nested((wait_queue_head_t *) cookie, POLLIN,
+			  1 + call_nests);
 	return 0;
 }
 
@@ -782,6 +801,15 @@ static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *k
 	if (!(epi->event.events & ~EP_PRIVATE_BITS))
 		goto out_unlock;
 
+	/*
+	 * Check the events coming with the callback. At this stage, not
+	 * every device reports the events in the "key" parameter of the
+	 * callback. We need to be able to handle both cases here, hence the
+	 * test for "key" != NULL before the event match test.
+	 */
+	if (key && !((unsigned long) key & epi->event.events))
+		goto out_unlock;
+
 	/*
 	 * If we are trasfering events to userspace, we can hold no locks
 	 * (because we're accessing user memory, and because of linux f_op->poll()
@@ -1254,7 +1282,6 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
 	case EPOLL_CTL_ADD:
 		if (!epi) {
 			epds.events |= POLLERR | POLLHUP;
-
 			error = ep_insert(ep, &epds, tfile, fd);
 		} else
 			error = -EEXIST;