[patch 3/3] OCFS2 Configurable timeouts - Protocol changes

Modify the OCFS2 handshake to ensure essential timeouts are configured
identically on all nodes.

Only allow changes when there are no connected peers

Improves the logic in o2net_advance_rx() which broke now that
sizeof(struct o2net_handshake) is greater than sizeof(struct o2net_msg)

Included is the field for userspace-heartbeat timeout to avoid the need for
further protocol changes.

Uses a global spinlock to ensure the decisions to update configfs entries
are made on the correct value.  The region covered by the spinlock when
incrementing the counter is much larger as this is the more critical case.

Small cleanup contributed by Adrian Bunk <bunk@stusta.de>

Signed-off-by: Andrew Beekhof <abeekhof@suse.de>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/cluster/tcp_internal.h b/fs/ocfs2/cluster/tcp_internal.h
index 56f7ee1..b700dc9 100644
--- a/fs/ocfs2/cluster/tcp_internal.h
+++ b/fs/ocfs2/cluster/tcp_internal.h
@@ -38,6 +38,9 @@
  * locking semantics of the file system using the protocol.  It should 
  * be somewhere else, I'm sure, but right now it isn't.
  *
+ * New in version 5:
+ * 	- Network timeout checking protocol
+ *
  * New in version 4:
  * 	- Remove i_generation from lock names for better stat performance.
  *
@@ -48,10 +51,14 @@
  * 	- full 64 bit i_size in the metadata lock lvbs
  * 	- introduction of "rw" lock and pushing meta/data locking down
  */
-#define O2NET_PROTOCOL_VERSION 4ULL
+#define O2NET_PROTOCOL_VERSION 5ULL
 struct o2net_handshake {
 	__be64	protocol_version;
 	__be64	connector_id;
+	__be32  o2hb_heartbeat_timeout_ms;
+	__be32  o2net_idle_timeout_ms;
+	__be32  o2net_keepalive_delay_ms;
+	__be32  o2net_reconnect_delay_ms;
 };
 
 struct o2net_node {