sunrpc: Save remote presentation address in svc_xprt for trace events

TP_printk defines a format string that is passed to user space for
converting raw trace event records to something human-readable.

My user space's printf (Oracle Linux 7), however, does not have a
%pI format specifier. The result is that what is supposed to be an
IP address in the output of "trace-cmd report" is just a string that
says the field couldn't be displayed.

To fix this, adopt the same approach as the client: maintain a pre-
formated presentation address for occasions when %pI is not
available.

The location of the trace_svc_send trace point is adjusted so that
rqst->rq_xprt is not NULL when the trace event is recorded.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

3 files changed, 6 insertions, 2 deletions

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 47384d0b1673..f745754a55ea 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -173,6 +173,7 @@ void svc_xprt_init(struct net *net, struct svc_xprt_class *xcl,
 	set_bit(XPT_BUSY, &xprt->xpt_flags);
 	rpc_init_wait_queue(&xprt->xpt_bc_pending, "xpt_bc_pending");
 	xprt->xpt_net = get_net(net);
+	strcpy(xprt->xpt_remotebuf, "uninitialized");
 }
 EXPORT_SYMBOL_GPL(svc_xprt_init);
 
@@ -894,12 +895,12 @@ int svc_send(struct svc_rqst *rqstp)
 		len = xprt->xpt_ops->xpo_sendto(rqstp);
 	mutex_unlock(&xprt->xpt_mutex);
 	rpc_wake_up(&xprt->xpt_bc_pending);
+	trace_svc_send(rqstp, len);
 	svc_xprt_release(rqstp);
 
 	if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
 		len = 0;
 out:
-	trace_svc_send(rqstp, len);
 	return len;
 }
 
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 9b6703588e35..4ca1d92b531a 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1310,6 +1310,7 @@ static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
 	set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags);
 	if (sk->sk_state == TCP_LISTEN) {
 		dprintk("setting up TCP socket for listening\n");
+		strcpy(svsk->sk_xprt.xpt_remotebuf, "listener");
 		set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags);
 		sk->sk_data_ready = svc_tcp_listen_data_ready;
 		set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 17da06d6b8e5..96cc8f6597d3 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -401,8 +401,10 @@ static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
 	 */
 	set_bit(XPT_CONG_CTRL, &cma_xprt->sc_xprt.xpt_flags);
 
-	if (listener)
+	if (listener) {
+		strcpy(cma_xprt->sc_xprt.xpt_remotebuf, "listener");
 		set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
+	}
 
 	return cma_xprt;
 }