SUNRPC: Treat the task and request as separate in the xprt_ops->send_request()

When we shift to using the transmit queue, then the task that holds the
write lock will not necessarily be the same as the one being transmitted.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

include/linux/sunrpc/xprt.h

@@ -140,7 +140,7 @@ struct rpc_xprt_ops {
 	void		(*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
 	int		(*buf_alloc)(struct rpc_task *task);
 	void		(*buf_free)(struct rpc_task *task);
-	int		(*send_request)(struct rpc_task *task);
+	int		(*send_request)(struct rpc_rqst *req, struct rpc_task *task);
 	void		(*set_retrans_timeout)(struct rpc_task *task);
 	void		(*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
 	void		(*release_request)(struct rpc_task *task);

net/sunrpc/xprt.c

@@ -1191,7 +1191,7 @@ void xprt_transmit(struct rpc_task *task)
 	}
 
 	connect_cookie = xprt->connect_cookie;
-	status = xprt->ops->send_request(task);
+	status = xprt->ops->send_request(req, task);
 	trace_xprt_transmit(xprt, req->rq_xid, status);
 	if (status != 0) {
 		task->tk_status = status;

net/sunrpc/xprtrdma/svc_rdma_backchannel.c

@@ -215,9 +215,8 @@ rpcrdma_bc_send_request(struct svcxprt_rdma *rdma, struct rpc_rqst *rqst)
  * connection.
  */
 static int
-xprt_rdma_bc_send_request(struct rpc_task *task)
+xprt_rdma_bc_send_request(struct rpc_rqst *rqst, struct rpc_task *task)
 {
-	struct rpc_rqst *rqst = task->tk_rqstp;
 	struct svc_xprt *sxprt = rqst->rq_xprt->bc_xprt;
 	struct svcxprt_rdma *rdma;
 	int ret;

net/sunrpc/xprtrdma/transport.c

@@ -706,9 +706,8 @@ xprt_rdma_free(struct rpc_task *task)
  *		sent. Do not try to send this message again.
  */
 static int
-xprt_rdma_send_request(struct rpc_task *task)
+xprt_rdma_send_request(struct rpc_rqst *rqst, struct rpc_task *task)
 {
-	struct rpc_rqst *rqst = task->tk_rqstp;
 	struct rpc_xprt *xprt = rqst->rq_xprt;
 	struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
@@ -741,7 +740,7 @@ xprt_rdma_send_request(struct rpc_task *task)
 	/* An RPC with no reply will throw off credit accounting,
 	 * so drop the connection to reset the credit grant.
 	 */
-	if (!rpc_reply_expected(task))
+	if (!rpc_reply_expected(rqst->rq_task))
 		goto drop_connection;
 	return 0;
 

net/sunrpc/xprtsock.c

@@ -449,12 +449,12 @@ static void xs_nospace_callback(struct rpc_task *task)
 
 /**
  * xs_nospace - place task on wait queue if transmit was incomplete
+ * @req: pointer to RPC request
  * @task: task to put to sleep
  *
  */
-static int xs_nospace(struct rpc_task *task)
+static int xs_nospace(struct rpc_rqst *req, struct rpc_task *task)
 {
-	struct rpc_rqst *req = task->tk_rqstp;
 	struct rpc_xprt *xprt = req->rq_xprt;
 	struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 	struct sock *sk = transport->inet;
@@ -513,6 +513,7 @@ static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
 
 /**
  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
+ * @req: pointer to RPC request
  * @task: RPC task that manages the state of an RPC request
  *
  * Return values:
@@ -522,9 +523,8 @@ static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
  * ENOTCONN:	Caller needs to invoke connect logic then call again
  *    other:	Some other error occured, the request was not sent
  */
-static int xs_local_send_request(struct rpc_task *task)
+static int xs_local_send_request(struct rpc_rqst *req, struct rpc_task *task)
 {
-	struct rpc_rqst *req = task->tk_rqstp;
 	struct rpc_xprt *xprt = req->rq_xprt;
 	struct sock_xprt *transport =
 				container_of(xprt, struct sock_xprt, xprt);
@@ -569,7 +569,7 @@ static int xs_local_send_request(struct rpc_task *task)
 	case -ENOBUFS:
 		break;
 	case -EAGAIN:
-		status = xs_nospace(task);
+		status = xs_nospace(req, task);
 		break;
 	default:
 		dprintk("RPC:       sendmsg returned unrecognized error %d\n",
@@ -585,6 +585,7 @@ static int xs_local_send_request(struct rpc_task *task)
 
 /**
  * xs_udp_send_request - write an RPC request to a UDP socket
+ * @req: pointer to RPC request
  * @task: address of RPC task that manages the state of an RPC request
  *
  * Return values:
@@ -594,9 +595,8 @@ static int xs_local_send_request(struct rpc_task *task)
  * ENOTCONN:	Caller needs to invoke connect logic then call again
  *    other:	Some other error occurred, the request was not sent
  */
-static int xs_udp_send_request(struct rpc_task *task)
+static int xs_udp_send_request(struct rpc_rqst *req, struct rpc_task *task)
 {
-	struct rpc_rqst *req = task->tk_rqstp;
 	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;
@@ -638,7 +638,7 @@ static int xs_udp_send_request(struct rpc_task *task)
 		/* Should we call xs_close() here? */
 		break;
 	case -EAGAIN:
-		status = xs_nospace(task);
+		status = xs_nospace(req, task);
 		break;
 	case -ENETUNREACH:
 	case -ENOBUFS:
@@ -658,6 +658,7 @@ static int xs_udp_send_request(struct rpc_task *task)
 
 /**
  * xs_tcp_send_request - write an RPC request to a TCP socket
+ * @req: pointer to RPC request
  * @task: address of RPC task that manages the state of an RPC request
  *
  * Return values:
@@ -670,9 +671,8 @@ static int xs_udp_send_request(struct rpc_task *task)
  * XXX: In the case of soft timeouts, should we eventually give up
  *	if sendmsg is not able to make progress?
  */
-static int xs_tcp_send_request(struct rpc_task *task)
+static int xs_tcp_send_request(struct rpc_rqst *req, struct rpc_task *task)
 {
-	struct rpc_rqst *req = task->tk_rqstp;
 	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;
@@ -697,7 +697,7 @@ static int xs_tcp_send_request(struct rpc_task *task)
 	 * completes while the socket holds a reference to the pages,
 	 * then we may end up resending corrupted data.
 	 */
-	if (task->tk_flags & RPC_TASK_SENT)
+	if (req->rq_task->tk_flags & RPC_TASK_SENT)
 		zerocopy = false;
 
 	if (test_bit(XPRT_SOCK_UPD_TIMEOUT, &transport->sock_state))
@@ -761,7 +761,7 @@ static int xs_tcp_send_request(struct rpc_task *task)
 		/* Should we call xs_close() here? */
 		break;
 	case -EAGAIN:
-		status = xs_nospace(task);
+		status = xs_nospace(req, task);
 		break;
 	case -ECONNRESET:
 	case -ECONNREFUSED:
@@ -2706,9 +2706,8 @@ static int bc_sendto(struct rpc_rqst *req)
 /*
  * The send routine. Borrows from svc_send
  */
-static int bc_send_request(struct rpc_task *task)
+static int bc_send_request(struct rpc_rqst *req, struct rpc_task *task)
 {
-	struct rpc_rqst *req = task->tk_rqstp;
 	struct svc_xprt	*xprt;
 	int len;