SUNRPC: Pass pointers to struct rpc_xprt to the congestion window

Avoid access to task->tk_xprt
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

include/linux/sunrpc/xprt.h

@@ -122,7 +122,7 @@ struct rpc_xprt_ops {
 	void		(*buf_free)(void *buffer);
 	int		(*send_request)(struct rpc_task *task);
 	void		(*set_retrans_timeout)(struct rpc_task *task);
-	void		(*timer)(struct rpc_task *task);
+	void		(*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
 	void		(*release_request)(struct rpc_task *task);
 	void		(*close)(struct rpc_xprt *xprt);
 	void		(*destroy)(struct rpc_xprt *xprt);
@@ -313,7 +313,7 @@ void			xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 void			xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 void			xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 void			xprt_write_space(struct rpc_xprt *xprt);
-void			xprt_adjust_cwnd(struct rpc_task *task, int result);
+void			xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 struct rpc_rqst *	xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 void			xprt_complete_rqst(struct rpc_task *task, int copied);
 void			xprt_release_rqst_cong(struct rpc_task *task);

net/sunrpc/xprt.c

@@ -438,15 +438,15 @@ EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
 
 /**
  * xprt_adjust_cwnd - adjust transport congestion window
+ * @xprt: pointer to xprt
  * @task: recently completed RPC request used to adjust window
  * @result: result code of completed RPC request
  *
  * We use a time-smoothed congestion estimator to avoid heavy oscillation.
  */
-void xprt_adjust_cwnd(struct rpc_task *task, int result)
+void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result)
 {
 	struct rpc_rqst *req = task->tk_rqstp;
-	struct rpc_xprt *xprt = task->tk_xprt;
 	unsigned long cwnd = xprt->cwnd;
 
 	if (result >= 0 && cwnd <= xprt->cong) {
@@ -834,7 +834,7 @@ static void xprt_timer(struct rpc_task *task)
 	spin_lock_bh(&xprt->transport_lock);
 	if (!req->rq_reply_bytes_recvd) {
 		if (xprt->ops->timer)
-			xprt->ops->timer(task);
+			xprt->ops->timer(xprt, task);
 	} else
 		task->tk_status = 0;
 	spin_unlock_bh(&xprt->transport_lock);

net/sunrpc/xprtsock.c

@@ -1005,7 +1005,7 @@ static void xs_udp_data_ready(struct sock *sk, int len)
 
 	UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
 
-	xprt_adjust_cwnd(task, copied);
+	xprt_adjust_cwnd(xprt, task, copied);
 	xprt_complete_rqst(task, copied);
 
  out_unlock:
@@ -1646,9 +1646,9 @@ static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t
  *
  * Adjust the congestion window after a retransmit timeout has occurred.
  */
-static void xs_udp_timer(struct rpc_task *task)
+static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 {
-	xprt_adjust_cwnd(task, -ETIMEDOUT);
+	xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
 }
 
 static unsigned short xs_get_random_port(void)