SUNRPC: Fix up calculation of client message length

In the case where a record marker was used, xs_sendpages() needs
to return the length of the payload + record marker so that we
operate correctly in the case of a partial transmission.
When the callers check return value, they therefore need to
take into account the record marker length.

Fixes: 06b5fc3a ("Merge tag 'nfs-rdma-for-5.1-1'...")
Cc: stable@vger.kernel.org # 5.1+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xprtsock.c

@@ -950,6 +950,8 @@ static int xs_local_send_request(struct rpc_rqst *req)
 	struct sock_xprt *transport =
 				container_of(xprt, struct sock_xprt, xprt);
 	struct xdr_buf *xdr = &req->rq_snd_buf;
+	rpc_fraghdr rm = xs_stream_record_marker(xdr);
+	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
 	int status;
 	int sent = 0;
 
@@ -964,9 +966,7 @@ static int xs_local_send_request(struct rpc_rqst *req)
 
 	req->rq_xtime = ktime_get();
 	status = xs_sendpages(transport->sock, NULL, 0, xdr,
-			      transport->xmit.offset,
-			      xs_stream_record_marker(xdr),
-			      &sent);
+			      transport->xmit.offset, rm, &sent);
 	dprintk("RPC:       %s(%u) = %d\n",
 			__func__, xdr->len - transport->xmit.offset, status);
 
@@ -976,7 +976,7 @@ static int xs_local_send_request(struct rpc_rqst *req)
 	if (likely(sent > 0) || status == 0) {
 		transport->xmit.offset += sent;
 		req->rq_bytes_sent = transport->xmit.offset;
-		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
+		if (likely(req->rq_bytes_sent >= msglen)) {
 			req->rq_xmit_bytes_sent += transport->xmit.offset;
 			transport->xmit.offset = 0;
 			return 0;
@@ -1097,6 +1097,8 @@ static int xs_tcp_send_request(struct rpc_rqst *req)
 	struct rpc_xprt *xprt = req->rq_xprt;
 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 	struct xdr_buf *xdr = &req->rq_snd_buf;
+	rpc_fraghdr rm = xs_stream_record_marker(xdr);
+	unsigned int msglen = rm ? req->rq_slen + sizeof(rm) : req->rq_slen;
 	bool vm_wait = false;
 	int status;
 	int sent;
@@ -1122,9 +1124,7 @@ static int xs_tcp_send_request(struct rpc_rqst *req)
 	while (1) {
 		sent = 0;
 		status = xs_sendpages(transport->sock, NULL, 0, xdr,
-				      transport->xmit.offset,
-				      xs_stream_record_marker(xdr),
-				      &sent);
+				      transport->xmit.offset, rm, &sent);
 
 		dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 				xdr->len - transport->xmit.offset, status);
@@ -1133,7 +1133,7 @@ static int xs_tcp_send_request(struct rpc_rqst *req)
 		 * reset the count of bytes sent. */
 		transport->xmit.offset += sent;
 		req->rq_bytes_sent = transport->xmit.offset;
-		if (likely(req->rq_bytes_sent >= req->rq_slen)) {
+		if (likely(req->rq_bytes_sent >= msglen)) {
 			req->rq_xmit_bytes_sent += transport->xmit.offset;
 			transport->xmit.offset = 0;
 			return 0;