SUNRPC: Add tracepoints to help debug socket connection issues

Add client side debugging to help trace socket connection/disconnection
and unexpected state change issues.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 143 insertions, 1 deletions

diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 43be87d5dd58..b74a8acd38fa 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -6,6 +6,8 @@
 
 #include <linux/sunrpc/sched.h>
 #include <linux/sunrpc/clnt.h>
+#include <net/tcp_states.h>
+#include <linux/net.h>
 #include <linux/tracepoint.h>
 
 DECLARE_EVENT_CLASS(rpc_task_status,
@@ -172,6 +174,135 @@ DEFINE_EVENT(rpc_task_queued, rpc_task_wakeup,
 
 );
 
+#define rpc_show_socket_state(state) \
+        __print_symbolic(state, \
+                { SS_FREE, "FREE" }, \
+                { SS_UNCONNECTED, "UNCONNECTED" }, \
+                { SS_CONNECTING, "CONNECTING," }, \
+                { SS_CONNECTED, "CONNECTED," }, \
+                { SS_DISCONNECTING, "DISCONNECTING" })
+
+#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" })
+
+DECLARE_EVENT_CLASS(xs_socket_event,
+
+                TP_PROTO(
+                        struct rpc_xprt *xprt,
+                        struct socket *socket
+                ),
+
+                TP_ARGS(xprt, socket),
+
+                TP_STRUCT__entry(
+                        __field(unsigned int, socket_state)
+                        __field(unsigned int, sock_state)
+                        __field(unsigned long long, ino)
+                        __string(dstaddr,
+                                xprt->address_strings[RPC_DISPLAY_ADDR])
+                        __string(dstport,
+                                xprt->address_strings[RPC_DISPLAY_PORT])
+                ),
+
+                TP_fast_assign(
+                        struct inode *inode = SOCK_INODE(socket);
+                        __entry->socket_state = socket->state;
+                        __entry->sock_state = socket->sk->sk_state;
+                        __entry->ino = (unsigned long long)inode->i_ino;
+                        __assign_str(dstaddr,
+                                xprt->address_strings[RPC_DISPLAY_ADDR]);
+                        __assign_str(dstport,
+                                xprt->address_strings[RPC_DISPLAY_PORT]);
+                ),
+
+                TP_printk(
+                        "socket:[%llu] dstaddr=%s/%s "
+                        "state=%u (%s) sk_state=%u (%s)",
+                        __entry->ino, __get_str(dstaddr), __get_str(dstport),
+                        __entry->socket_state,
+                        rpc_show_socket_state(__entry->socket_state),
+                        __entry->sock_state,
+                        rpc_show_sock_state(__entry->sock_state)
+                )
+);
+#define DEFINE_RPC_SOCKET_EVENT(name) \
+        DEFINE_EVENT(xs_socket_event, name, \
+                        TP_PROTO( \
+                                struct rpc_xprt *xprt, \
+                                struct socket *socket \
+                        ), \
+                        TP_ARGS(xprt, socket))
+
+DECLARE_EVENT_CLASS(xs_socket_event_done,
+
+                TP_PROTO(
+                        struct rpc_xprt *xprt,
+                        struct socket *socket,
+                        int error
+                ),
+
+                TP_ARGS(xprt, socket, error),
+
+                TP_STRUCT__entry(
+                        __field(int, error)
+                        __field(unsigned int, socket_state)
+                        __field(unsigned int, sock_state)
+                        __field(unsigned long long, ino)
+                        __string(dstaddr,
+                                xprt->address_strings[RPC_DISPLAY_ADDR])
+                        __string(dstport,
+                                xprt->address_strings[RPC_DISPLAY_PORT])
+                ),
+
+                TP_fast_assign(
+                        struct inode *inode = SOCK_INODE(socket);
+                        __entry->socket_state = socket->state;
+                        __entry->sock_state = socket->sk->sk_state;
+                        __entry->ino = (unsigned long long)inode->i_ino;
+                        __entry->error = error;
+                        __assign_str(dstaddr,
+                                xprt->address_strings[RPC_DISPLAY_ADDR]);
+                        __assign_str(dstport,
+                                xprt->address_strings[RPC_DISPLAY_PORT]);
+                ),
+
+                TP_printk(
+                        "error=%d socket:[%llu] dstaddr=%s/%s "
+                        "state=%u (%s) sk_state=%u (%s)",
+                        __entry->error,
+                        __entry->ino, __get_str(dstaddr), __get_str(dstport),
+                        __entry->socket_state,
+                        rpc_show_socket_state(__entry->socket_state),
+                        __entry->sock_state,
+                        rpc_show_sock_state(__entry->sock_state)
+                )
+);
+#define DEFINE_RPC_SOCKET_EVENT_DONE(name) \
+        DEFINE_EVENT(xs_socket_event_done, name, \
+                        TP_PROTO( \
+                                struct rpc_xprt *xprt, \
+                                struct socket *socket, \
+                                int error \
+                        ), \
+                        TP_ARGS(xprt, socket, error))
+
+DEFINE_RPC_SOCKET_EVENT(rpc_socket_state_change);
+DEFINE_RPC_SOCKET_EVENT_DONE(rpc_socket_connect);
+DEFINE_RPC_SOCKET_EVENT_DONE(rpc_socket_reset_connection);
+DEFINE_RPC_SOCKET_EVENT(rpc_socket_close);
+DEFINE_RPC_SOCKET_EVENT(rpc_socket_shutdown);
+
 #endif /* _TRACE_SUNRPC_H */
 
 #include <trace/define_trace.h>
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index ddf0602603bd..b98bce5461b5 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -47,6 +47,8 @@
 #include <net/udp.h>
 #include <net/tcp.h>
 
+#include <trace/events/sunrpc.h>
+
 #include "sunrpc.h"
 
 static void xs_close(struct rpc_xprt *xprt);
@@ -665,8 +667,10 @@ static void xs_tcp_shutdown(struct rpc_xprt *xprt)
         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
         struct socket *sock = transport->sock;
 
-        if (sock != NULL)
+        if (sock != NULL) {
                 kernel_sock_shutdown(sock, SHUT_WR);
+                trace_rpc_socket_shutdown(xprt, sock);
+        }
 }
 
 /**
@@ -811,6 +815,7 @@ static void xs_reset_transport(struct sock_xprt *transport)
 
         sk->sk_no_check = 0;
 
+        trace_rpc_socket_close(&transport->xprt, sock);
         sock_release(sock);
 }
 
@@ -1492,6 +1497,7 @@ static void xs_tcp_state_change(struct sock *sk)
                         sock_flag(sk, SOCK_ZAPPED),
                         sk->sk_shutdown);
 
+        trace_rpc_socket_state_change(xprt, sk->sk_socket);
         switch (sk->sk_state) {
         case TCP_ESTABLISHED:
                 spin_lock(&xprt->transport_lock);
@@ -1896,6 +1902,7 @@ static int xs_local_setup_socket(struct sock_xprt *transport)
                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
 
         status = xs_local_finish_connecting(xprt, sock);
+        trace_rpc_socket_connect(xprt, sock, status);
         switch (status) {
         case 0:
                 dprintk("RPC:       xprt %p connected to %s\n",
@@ -2039,6 +2046,7 @@ static void xs_udp_setup_socket(struct work_struct *work)
                         xprt->address_strings[RPC_DISPLAY_PORT]);
 
         xs_udp_finish_connecting(xprt, sock);
+        trace_rpc_socket_connect(xprt, sock, 0);
         status = 0;
 out:
         xprt_clear_connecting(xprt);
@@ -2064,6 +2072,8 @@ static void xs_abort_connection(struct sock_xprt *transport)
         memset(&any, 0, sizeof(any));
         any.sa_family = AF_UNSPEC;
         result = kernel_connect(transport->sock, &any, sizeof(any), 0);
+        trace_rpc_socket_reset_connection(&transport->xprt,
+                        transport->sock, result);
         if (!result)
                 xs_sock_reset_connection_flags(&transport->xprt);
         dprintk("RPC:       AF_UNSPEC connect return code %d\n", result);
@@ -2194,6 +2204,7 @@ static void xs_tcp_setup_socket(struct work_struct *work)
                         xprt->address_strings[RPC_DISPLAY_PORT]);
 
         status = xs_tcp_finish_connecting(xprt, sock);
+        trace_rpc_socket_connect(xprt, sock, status);
         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
                         xprt, -status, xprt_connected(xprt),
                         sock->sk->sk_state);