PM: Rename CAP_EPOLLWAKEUP to CAP_BLOCK_SUSPEND

As discussed in
http://thread.gmane.org/gmane.linux.kernel/1249726/focus=1288990,
the capability introduced in 4d7e30d989
to govern EPOLLWAKEUP seems misnamed: this capability is about governing
the ability to suspend the system, not using a particular API flag
(EPOLLWAKEUP). We should make the name of the capability more general
to encourage reuse in related cases. (Whether or not this capability
should also be used to govern the use of /sys/power/wake_lock is a
question that needs to be separately resolved.)

This patch renames the capability to CAP_BLOCK_SUSPEND. In order to ensure
that the old capability name doesn't make it out into the wild, could you
please apply and push up the tree to ensure that it is incorporated
for the 3.5 release.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

fs/eventpoll.c

@@ -1710,7 +1710,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
 		goto error_tgt_fput;
 
 	/* Check if EPOLLWAKEUP is allowed */
-	if ((epds.events & EPOLLWAKEUP) && !capable(CAP_EPOLLWAKEUP))
+	if ((epds.events & EPOLLWAKEUP) && !capable(CAP_BLOCK_SUSPEND))
 		epds.events &= ~EPOLLWAKEUP;
 
 	/*

include/linux/capability.h

@@ -360,11 +360,11 @@ struct cpu_vfs_cap_data {
 
 #define CAP_WAKE_ALARM            35
 
-/* Allow preventing system suspends while epoll events are pending */
+/* Allow preventing system suspends */
 
-#define CAP_EPOLLWAKEUP      36
+#define CAP_BLOCK_SUSPEND    36
 
-#define CAP_LAST_CAP         CAP_EPOLLWAKEUP
+#define CAP_LAST_CAP         CAP_BLOCK_SUSPEND
 
 #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP)
 

include/linux/eventpoll.h

@@ -34,7 +34,7 @@
  * re-allowed until epoll_wait is called again after consuming the wakeup
  * event(s).
  *
- * Requires CAP_EPOLLWAKEUP
+ * Requires CAP_BLOCK_SUSPEND
  */
 #define EPOLLWAKEUP (1 << 29)