SUNRPC: Refactor RPC call encoding

Move the call encoding so that it occurs before the transport connection
etc.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

include/linux/sunrpc/xprt.h

@@ -347,6 +347,7 @@ bool			xprt_prepare_transmit(struct rpc_task *task);
 void			xprt_request_enqueue_transmit(struct rpc_task *task);
 void			xprt_request_enqueue_receive(struct rpc_task *task);
 void			xprt_request_wait_receive(struct rpc_task *task);
+bool			xprt_request_need_retransmit(struct rpc_task *task);
 void			xprt_transmit(struct rpc_task *task);
 void			xprt_end_transmit(struct rpc_task *task);
 int			xprt_adjust_timeout(struct rpc_rqst *req);

net/sunrpc/clnt.c

@@ -61,6 +61,7 @@ static void	call_start(struct rpc_task *task);
 static void	call_reserve(struct rpc_task *task);
 static void	call_reserveresult(struct rpc_task *task);
 static void	call_allocate(struct rpc_task *task);
+static void	call_encode(struct rpc_task *task);
 static void	call_decode(struct rpc_task *task);
 static void	call_bind(struct rpc_task *task);
 static void	call_bind_status(struct rpc_task *task);
@@ -1140,7 +1141,8 @@ struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
 	struct xdr_buf *xbufp = &req->rq_snd_buf;
 	struct rpc_task_setup task_setup_data = {
 		.callback_ops = &rpc_default_ops,
-		.flags = RPC_TASK_SOFTCONN,
+		.flags = RPC_TASK_SOFTCONN |
+			RPC_TASK_NO_RETRANS_TIMEOUT,
 	};
 
 	dprintk("RPC: rpc_run_bc_task req= %p\n", req);
@@ -1160,7 +1162,6 @@ struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
 	task->tk_action = call_bc_transmit;
 	atomic_inc(&task->tk_count);
 	WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
-	xprt_request_enqueue_transmit(task);
 	rpc_execute(task);
 
 	dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
@@ -1680,7 +1681,7 @@ call_allocate(struct rpc_task *task)
 	dprint_status(task);
 
 	task->tk_status = 0;
-	task->tk_action = call_bind;
+	task->tk_action = call_encode;
 
 	if (req->rq_buffer)
 		return;
@@ -1724,12 +1725,12 @@ call_allocate(struct rpc_task *task)
 static int
 rpc_task_need_encode(struct rpc_task *task)
 {
-	return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0;
+	return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
+		(!(task->tk_flags & RPC_TASK_SENT) ||
+		 !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
+		 xprt_request_need_retransmit(task));
 }
 
-/*
- * 3.	Encode arguments of an RPC call
- */
 static void
 rpc_xdr_encode(struct rpc_task *task)
 {
@@ -1745,6 +1746,7 @@ rpc_xdr_encode(struct rpc_task *task)
 	xdr_buf_init(&req->rq_rcv_buf,
 		     req->rq_rbuffer,
 		     req->rq_rcvsize);
+	req->rq_bytes_sent = 0;
 
 	p = rpc_encode_header(task);
 	if (p == NULL) {
@@ -1761,6 +1763,34 @@ rpc_xdr_encode(struct rpc_task *task)
 			task->tk_msg.rpc_argp);
 }
 
+/*
+ * 3.	Encode arguments of an RPC call
+ */
+static void
+call_encode(struct rpc_task *task)
+{
+	if (!rpc_task_need_encode(task))
+		goto out;
+	/* Encode here so that rpcsec_gss can use correct sequence number. */
+	rpc_xdr_encode(task);
+	/* Did the encode result in an error condition? */
+	if (task->tk_status != 0) {
+		/* Was the error nonfatal? */
+		if (task->tk_status == -EAGAIN)
+			rpc_delay(task, HZ >> 4);
+		else
+			rpc_exit(task, task->tk_status);
+		return;
+	}
+
+	/* Add task to reply queue before transmission to avoid races */
+	if (rpc_reply_expected(task))
+		xprt_request_enqueue_receive(task);
+	xprt_request_enqueue_transmit(task);
+out:
+	task->tk_action = call_bind;
+}
+
 /*
  * 4.	Get the server port number if not yet set
  */
@@ -1945,24 +1975,8 @@ call_transmit(struct rpc_task *task)
 	dprint_status(task);
 
 	task->tk_action = call_transmit_status;
-	/* Encode here so that rpcsec_gss can use correct sequence number. */
-	if (rpc_task_need_encode(task)) {
-		rpc_xdr_encode(task);
-		/* Did the encode result in an error condition? */
-		if (task->tk_status != 0) {
-			/* Was the error nonfatal? */
-			if (task->tk_status == -EAGAIN)
-				rpc_delay(task, HZ >> 4);
-			else
-				rpc_exit(task, task->tk_status);
-			return;
-		}
-	}
-
-	/* Add task to reply queue before transmission to avoid races */
-	if (rpc_reply_expected(task))
-		xprt_request_enqueue_receive(task);
-	xprt_request_enqueue_transmit(task);
+	if (!test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate))
+		return;
 
 	if (!xprt_prepare_transmit(task))
 		return;
@@ -1997,9 +2011,9 @@ call_transmit_status(struct rpc_task *task)
 		xprt_end_transmit(task);
 		break;
 	case -EBADMSG:
-		task->tk_action = call_transmit;
-		task->tk_status = 0;
 		xprt_end_transmit(task);
+		task->tk_status = 0;
+		task->tk_action = call_encode;
 		break;
 		/*
 		 * Special cases: if we've been waiting on the
@@ -2048,6 +2062,9 @@ call_bc_transmit(struct rpc_task *task)
 {
 	struct rpc_rqst *req = task->tk_rqstp;
 
+	if (rpc_task_need_encode(task))
+		xprt_request_enqueue_transmit(task);
+
 	if (!xprt_prepare_transmit(task))
 		goto out_retry;
 
@@ -2169,7 +2186,7 @@ call_status(struct rpc_task *task)
 	case -EPIPE:
 	case -ENOTCONN:
 	case -EAGAIN:
-		task->tk_action = call_bind;
+		task->tk_action = call_encode;
 		break;
 	case -EIO:
 		/* shutdown or soft timeout */
@@ -2234,7 +2251,7 @@ call_timeout(struct rpc_task *task)
 	rpcauth_invalcred(task);
 
 retry:
-	task->tk_action = call_bind;
+	task->tk_action = call_encode;
 	task->tk_status = 0;
 }
 
@@ -2278,7 +2295,7 @@ call_decode(struct rpc_task *task)
 
 	if (req->rq_rcv_buf.len < 12) {
 		if (!RPC_IS_SOFT(task)) {
-			task->tk_action = call_bind;
+			task->tk_action = call_encode;
 			goto out_retry;
 		}
 		dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
@@ -2409,7 +2426,7 @@ rpc_verify_header(struct rpc_task *task)
 			task->tk_garb_retry--;
 			dprintk("RPC: %5u %s: retry garbled creds\n",
 					task->tk_pid, __func__);
-			task->tk_action = call_bind;
+			task->tk_action = call_encode;
 			goto out_retry;
 		case RPC_AUTH_TOOWEAK:
 			printk(KERN_NOTICE "RPC: server %s requires stronger "
@@ -2478,7 +2495,7 @@ rpc_verify_header(struct rpc_task *task)
 		task->tk_garb_retry--;
 		dprintk("RPC: %5u %s: retrying\n",
 				task->tk_pid, __func__);
-		task->tk_action = call_bind;
+		task->tk_action = call_encode;
 out_retry:
 		return ERR_PTR(-EAGAIN);
 	}

net/sunrpc/xprt.c

@@ -1058,18 +1058,10 @@ void xprt_request_wait_receive(struct rpc_task *task)
 	spin_unlock(&xprt->queue_lock);
 }
 
-static bool
-xprt_request_need_transmit(struct rpc_task *task)
-{
-	return !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
-		xprt_request_retransmit_after_disconnect(task);
-}
-
 static bool
 xprt_request_need_enqueue_transmit(struct rpc_task *task, struct rpc_rqst *req)
 {
-	return xprt_request_need_transmit(task) &&
-		!test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
+	return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
 }
 
 /**
@@ -1124,6 +1116,18 @@ xprt_request_dequeue_transmit(struct rpc_task *task)
 	spin_unlock(&xprt->queue_lock);
 }
 
+/**
+ * xprt_request_need_retransmit - Test if a task needs retransmission
+ * @task: pointer to rpc_task
+ *
+ * Test for whether a connection breakage requires the task to retransmit
+ */
+bool
+xprt_request_need_retransmit(struct rpc_task *task)
+{
+	return xprt_request_retransmit_after_disconnect(task);
+}
+
 /**
  * xprt_prepare_transmit - reserve the transport before sending a request
  * @task: RPC task about to send a request