xprtrdma: Add trace points in the client-side backchannel code paths

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

include/trace/events/rpcrdma.h

@@ -267,6 +267,39 @@ DECLARE_EVENT_CLASS(xprtrdma_mr,
 				), \
 				TP_ARGS(mr))
 
+DECLARE_EVENT_CLASS(xprtrdma_cb_event,
+	TP_PROTO(
+		const struct rpc_rqst *rqst
+	),
+
+	TP_ARGS(rqst),
+
+	TP_STRUCT__entry(
+		__field(const void *, rqst)
+		__field(const void *, rep)
+		__field(const void *, req)
+		__field(u32, xid)
+	),
+
+	TP_fast_assign(
+		__entry->rqst = rqst;
+		__entry->req = rpcr_to_rdmar(rqst);
+		__entry->rep = rpcr_to_rdmar(rqst)->rl_reply;
+		__entry->xid = be32_to_cpu(rqst->rq_xid);
+	),
+
+	TP_printk("xid=0x%08x, rqst=%p req=%p rep=%p",
+		__entry->xid, __entry->rqst, __entry->req, __entry->rep
+	)
+);
+
+#define DEFINE_CB_EVENT(name)						\
+		DEFINE_EVENT(xprtrdma_cb_event, name,			\
+				TP_PROTO(				\
+					const struct rpc_rqst *rqst	\
+				),					\
+				TP_ARGS(rqst))
+
 /**
  ** Connection events
  **/
@@ -719,6 +752,41 @@ TRACE_EVENT(xprtrdma_decode_seg,
 	)
 );
 
+/**
+ ** Callback events
+ **/
+
+TRACE_EVENT(xprtrdma_cb_setup,
+	TP_PROTO(
+		const struct rpcrdma_xprt *r_xprt,
+		unsigned int reqs
+	),
+
+	TP_ARGS(r_xprt, reqs),
+
+	TP_STRUCT__entry(
+		__field(const void *, r_xprt)
+		__field(unsigned int, reqs)
+		__string(addr, rpcrdma_addrstr(r_xprt))
+		__string(port, rpcrdma_portstr(r_xprt))
+	),
+
+	TP_fast_assign(
+		__entry->r_xprt = r_xprt;
+		__entry->reqs = reqs;
+		__assign_str(addr, rpcrdma_addrstr(r_xprt));
+		__assign_str(port, rpcrdma_portstr(r_xprt));
+	),
+
+	TP_printk("peer=[%s]:%s r_xprt=%p: %u reqs",
+		__get_str(addr), __get_str(port),
+		__entry->r_xprt, __entry->reqs
+	)
+);
+
+DEFINE_CB_EVENT(xprtrdma_cb_call);
+DEFINE_CB_EVENT(xprtrdma_cb_reply);
+
 #endif /* _TRACE_RPCRDMA_H */
 
 #include <trace/define_trace.h>

net/sunrpc/xprtrdma/backchannel.c

@@ -140,7 +140,7 @@ int xprt_rdma_bc_setup(struct rpc_xprt *xprt, unsigned int reqs)
 
 	buffer->rb_bc_srv_max_requests = reqs;
 	request_module("svcrdma");
-
+	trace_xprtrdma_cb_setup(r_xprt, reqs);
 	return 0;
 
 out_free:
@@ -212,6 +212,8 @@ static int rpcrdma_bc_marshal_reply(struct rpc_rqst *rqst)
 	if (rpcrdma_prepare_send_sges(r_xprt, req, RPCRDMA_HDRLEN_MIN,
 				      &rqst->rq_snd_buf, rpcrdma_noch))
 		return -EIO;
+
+	trace_xprtrdma_cb_reply(rqst);
 	return 0;
 }
 
@@ -331,7 +333,6 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
 				struct rpc_rqst, rq_bc_pa_list);
 	list_del(&rqst->rq_bc_pa_list);
 	spin_unlock(&xprt->bc_pa_lock);
-	dprintk("RPC:       %s: using rqst %p\n", __func__, rqst);
 
 	/* Prepare rqst */
 	rqst->rq_reply_bytes_recvd = 0;
@@ -352,9 +353,8 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
 	 * the Upper Layer is done decoding it.
 	 */
 	req = rpcr_to_rdmar(rqst);
-	dprintk("RPC:       %s: attaching rep %p to req %p\n",
-		__func__, rep, req);
 	req->rl_reply = rep;
+	trace_xprtrdma_cb_call(rqst);
 
 	/* Queue rqst for ULP's callback service */
 	bc_serv = xprt->bc_serv;

net/sunrpc/xprtrdma/xprt_rdma.h

@@ -365,7 +365,7 @@ rpcrdma_set_xprtdata(struct rpc_rqst *rqst, struct rpcrdma_req *req)
 }
 
 static inline struct rpcrdma_req *
-rpcr_to_rdmar(struct rpc_rqst *rqst)
+rpcr_to_rdmar(const struct rpc_rqst *rqst)
 {
 	return rqst->rq_xprtdata;
 }