SUNRPC: Fix up tracking of timeouts

Add a helper to ensure that debugfs and friends print out the
correct current task timeout value.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/sched.c

@@ -58,6 +58,20 @@ static struct rpc_wait_queue delay_queue;
 struct workqueue_struct *rpciod_workqueue __read_mostly;
 struct workqueue_struct *xprtiod_workqueue __read_mostly;
 
+unsigned long
+rpc_task_timeout(const struct rpc_task *task)
+{
+	unsigned long timeout = READ_ONCE(task->tk_timeout);
+
+	if (timeout != 0) {
+		unsigned long now = jiffies;
+		if (time_before(now, timeout))
+			return timeout - now;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rpc_task_timeout);
+
 /*
  * Disable the timer for a given RPC task. Should be called with
  * queue->lock and bh_disabled in order to avoid races within