ocfs2/net: Add debug interface to o2net

This patch exposes o2net information via debugfs. The information includes
the list of sockets (sock_containers) as well as the list of outstanding
messages (send_tracking). Useful for o2dlm debugging.

(This patch is derived from an earlier one written by Zach Brown that
exposed the same information via /proc.)

[Mark: checkpatch fixes]

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Reviewed-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

fs/ocfs2/cluster/tcp.h

@@ -117,4 +117,36 @@ int o2net_num_connected_peers(void);
 int o2net_init(void);
 void o2net_exit(void);
 
+struct o2net_send_tracking;
+struct o2net_sock_container;
+
+#ifdef CONFIG_DEBUG_FS
+int o2net_debugfs_init(void);
+void o2net_debugfs_exit(void);
+void o2net_debug_add_nst(struct o2net_send_tracking *nst);
+void o2net_debug_del_nst(struct o2net_send_tracking *nst);
+void o2net_debug_add_sc(struct o2net_sock_container *sc);
+void o2net_debug_del_sc(struct o2net_sock_container *sc);
+#else
+static int o2net_debugfs_init(void)
+{
+	return 0;
+}
+static void o2net_debugfs_exit(void)
+{
+}
+static void o2net_debug_add_nst(struct o2net_send_tracking *nst)
+{
+}
+static void o2net_debug_del_nst(struct o2net_send_tracking *nst)
+{
+}
+static void o2net_debug_add_sc(struct o2net_sock_container *sc)
+{
+}
+static void o2net_debug_del_sc(struct o2net_sock_container *sc)
+{
+}
+#endif	/* CONFIG_DEBUG_FS */
+
 #endif /* O2CLUSTER_TCP_H */