SUNRPC: Export enums in tracepoints to user space

The enums used in the tracepoints for __print_symbolic() have their
names shown in the tracepoint format files. User space tools do not know
how to convert those names into their values to be able to convert the
binary data.

Use TRACE_DEFINE_ENUM() to export the enum names to their values for
userspace to do the parsing correctly.

Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org

Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

include/trace/events/sunrpc.h

@@ -179,27 +179,53 @@ DEFINE_EVENT(rpc_task_queued, rpc_task_wakeup,
 
 );
 
+/*
+ * First define the enums in the below macros to be exported to userspace
+ * via TRACE_DEFINE_ENUM().
+ */
+#undef EM
+#undef EMe
+#define EM(a, b)	TRACE_DEFINE_ENUM(a);
+#define EMe(a, b)	TRACE_DEFINE_ENUM(a);
+
+#define RPC_SHOW_SOCKET				\
+	EM( SS_FREE, "FREE" )			\
+	EM( SS_UNCONNECTED, "UNCONNECTED" )	\
+	EM( SS_CONNECTING, "CONNECTING," )	\
+	EM( SS_CONNECTED, "CONNECTED," )	\
+	EMe(SS_DISCONNECTING, "DISCONNECTING" )
+
 #define rpc_show_socket_state(state) \
-	__print_symbolic(state, \
-		{ SS_FREE, "FREE" }, \
-		{ SS_UNCONNECTED, "UNCONNECTED" }, \
-		{ SS_CONNECTING, "CONNECTING," }, \
-		{ SS_CONNECTED, "CONNECTED," }, \
-		{ SS_DISCONNECTING, "DISCONNECTING" })
+	__print_symbolic(state, RPC_SHOW_SOCKET)
+
+RPC_SHOW_SOCKET
+
+#define RPC_SHOW_SOCK				\
+	EM( TCP_ESTABLISHED, "ESTABLISHED" )	\
+	EM( TCP_SYN_SENT, "SYN_SENT" )		\
+	EM( TCP_SYN_RECV, "SYN_RECV" )		\
+	EM( TCP_FIN_WAIT1, "FIN_WAIT1" )	\
+	EM( TCP_FIN_WAIT2, "FIN_WAIT2" )	\
+	EM( TCP_TIME_WAIT, "TIME_WAIT" )	\
+	EM( TCP_CLOSE, "CLOSE" )		\
+	EM( TCP_CLOSE_WAIT, "CLOSE_WAIT" )	\
+	EM( TCP_LAST_ACK, "LAST_ACK" )		\
+	EM( TCP_LISTEN, "LISTEN" )		\
+	EMe( TCP_CLOSING, "CLOSING" )
 
 #define rpc_show_sock_state(state) \
-	__print_symbolic(state, \
-		{ TCP_ESTABLISHED, "ESTABLISHED" }, \
-		{ TCP_SYN_SENT, "SYN_SENT" }, \
-		{ TCP_SYN_RECV, "SYN_RECV" }, \
-		{ TCP_FIN_WAIT1, "FIN_WAIT1" }, \
-		{ TCP_FIN_WAIT2, "FIN_WAIT2" }, \
-		{ TCP_TIME_WAIT, "TIME_WAIT" }, \
-		{ TCP_CLOSE, "CLOSE" }, \
-		{ TCP_CLOSE_WAIT, "CLOSE_WAIT" }, \
-		{ TCP_LAST_ACK, "LAST_ACK" }, \
-		{ TCP_LISTEN, "LISTEN" }, \
-		{ TCP_CLOSING, "CLOSING" })
+	__print_symbolic(state, RPC_SHOW_SOCK)
+
+RPC_SHOW_SOCK
+
+/*
+ * Now redefine the EM() and EMe() macros to map the enums to the strings
+ * that will be printed in the output.
+ */
+#undef EM
+#undef EMe
+#define EM(a, b)	{a, b},
+#define EMe(a, b)	{a, b}
 
 DECLARE_EVENT_CLASS(xs_socket_event,