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>

include/linux/sunrpc/sched.h

@@ -226,6 +226,7 @@ void		rpc_execute(struct rpc_task *);
 void		rpc_init_priority_wait_queue(struct rpc_wait_queue *, const char *);
 void		rpc_init_wait_queue(struct rpc_wait_queue *, const char *);
 void		rpc_destroy_wait_queue(struct rpc_wait_queue *);
+unsigned long	rpc_task_timeout(const struct rpc_task *task);
 void		rpc_sleep_on_timeout(struct rpc_wait_queue *queue,
 					struct rpc_task *task,
 					rpc_action action,

include/trace/events/sunrpc.h

@@ -186,7 +186,7 @@ DECLARE_EVENT_CLASS(rpc_task_queued,
 		__entry->client_id = task->tk_client ?
 				     task->tk_client->cl_clid : -1;
 		__entry->task_id = task->tk_pid;
-		__entry->timeout = task->tk_timeout;
+		__entry->timeout = rpc_task_timeout(task);
 		__entry->runstate = task->tk_runstate;
 		__entry->status = task->tk_status;
 		__entry->flags = task->tk_flags;

net/sunrpc/clnt.c

@@ -2874,7 +2874,7 @@ static void rpc_show_task(const struct rpc_clnt *clnt,
 
 	printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
 		task->tk_pid, task->tk_flags, task->tk_status,
-		clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
+		clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
 		clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
 		task->tk_action, rpc_waitq);
 }

net/sunrpc/debugfs.c

@@ -33,7 +33,7 @@ tasks_show(struct seq_file *f, void *v)
 
 	seq_printf(f, "%5u %04x %6d 0x%x 0x%x %8ld %ps %sv%u %s a:%ps q:%s\n",
 		task->tk_pid, task->tk_flags, task->tk_status,
-		clnt->cl_clid, xid, task->tk_timeout, task->tk_ops,
+		clnt->cl_clid, xid, rpc_task_timeout(task), task->tk_ops,
 		clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
 		task->tk_action, rpc_waitq);
 	return 0;

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