SUNRPC: Add tracepoint for socket errors

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

include/trace/events/sunrpc.h

@@ -301,6 +301,7 @@ DECLARE_EVENT_CLASS(xs_socket_event_done,
 
 DEFINE_RPC_SOCKET_EVENT(rpc_socket_state_change);
 DEFINE_RPC_SOCKET_EVENT_DONE(rpc_socket_connect);
+DEFINE_RPC_SOCKET_EVENT_DONE(rpc_socket_error);
 DEFINE_RPC_SOCKET_EVENT_DONE(rpc_socket_reset_connection);
 DEFINE_RPC_SOCKET_EVENT(rpc_socket_close);
 DEFINE_RPC_SOCKET_EVENT(rpc_socket_shutdown);

net/sunrpc/xprtsock.c

@@ -837,6 +837,7 @@ static void xs_error_report(struct sock *sk)
 		goto out;
 	dprintk("RPC:       xs_error_report client %p, error=%d...\n",
 			xprt, -err);
+	trace_rpc_socket_error(xprt, sk->sk_socket, err);
 	xprt_wake_pending_tasks(xprt, err);
  out:
 	read_unlock_bh(&sk->sk_callback_lock);