SUNRPC: Test whether the task is queued before grabbing the queue spinlocks

When asked to wake up an RPC task, it makes sense to test whether or not
the task is still queued.

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

net/sunrpc/sched.c

@@ -479,6 +479,8 @@ void rpc_wake_up_queued_task_on_wq(struct workqueue_struct *wq,
 		struct rpc_wait_queue *queue,
 		struct rpc_task *task)
 {
+	if (!RPC_IS_QUEUED(task))
+		return;
 	spin_lock_bh(&queue->lock);
 	rpc_wake_up_task_on_wq_queue_locked(wq, queue, task);
 	spin_unlock_bh(&queue->lock);
@@ -489,6 +491,8 @@ void rpc_wake_up_queued_task_on_wq(struct workqueue_struct *wq,
  */
 void rpc_wake_up_queued_task(struct rpc_wait_queue *queue, struct rpc_task *task)
 {
+	if (!RPC_IS_QUEUED(task))
+		return;
 	spin_lock_bh(&queue->lock);
 	rpc_wake_up_task_queue_locked(queue, task);
 	spin_unlock_bh(&queue->lock);