1 files changed, 11 insertions, 18 deletions

diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index f8529fc8e54..93a7a4e94d8 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -254,7 +254,7 @@ static int rpc_wait_bit_killable(void *word)
 {
 	if (fatal_signal_pending(current))
 		return -ERESTARTSYS;
-	freezable_schedule();
+	freezable_schedule_unsafe();
 	return 0;
 }
 
@@ -324,11 +324,17 @@ EXPORT_SYMBOL_GPL(__rpc_wait_for_completion_task);
  * Note: If the task is ASYNC, and is being made runnable after sitting on an
  * rpc_wait_queue, this must be called with the queue spinlock held to protect
  * the wait queue operation.
+ * Note the ordering of rpc_test_and_set_running() and rpc_clear_queued(),
+ * which is needed to ensure that __rpc_execute() doesn't loop (due to the
+ * lockless RPC_IS_QUEUED() test) before we've had a chance to test
+ * the RPC_TASK_RUNNING flag.
  */
 static void rpc_make_runnable(struct rpc_task *task)
 {
+	bool need_wakeup = !rpc_test_and_set_running(task);
+
 	rpc_clear_queued(task);
-	if (rpc_test_and_set_running(task))
+	if (!need_wakeup)
 		return;
 	if (RPC_IS_ASYNC(task)) {
 		INIT_WORK(&task->u.tk_work, rpc_async_schedule);
@@ -440,20 +446,6 @@ static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue *queue, struct r
 }
 
 /*
- * Tests whether rpc queue is empty
- */
-int rpc_queue_empty(struct rpc_wait_queue *queue)
-{
-	int res;
-
-	spin_lock_bh(&queue->lock);
-	res = queue->qlen;
-	spin_unlock_bh(&queue->lock);
-	return res == 0;
-}
-EXPORT_SYMBOL_GPL(rpc_queue_empty);
-
-/*
  * Wake up a task on a specific queue
  */
 void rpc_wake_up_queued_task(struct rpc_wait_queue *queue, struct rpc_task *task)
@@ -798,7 +790,6 @@ static void __rpc_execute(struct rpc_task *task)
 			task->tk_flags |= RPC_TASK_KILLED;
 			rpc_exit(task, -ERESTARTSYS);
 		}
-		rpc_set_running(task);
 		dprintk("RPC: %5u sync task resuming\n", task->tk_pid);
 	}
 
@@ -819,9 +810,11 @@ static void __rpc_execute(struct rpc_task *task)
  */
 void rpc_execute(struct rpc_task *task)
 {
+	bool is_async = RPC_IS_ASYNC(task);
+
 	rpc_set_active(task);
 	rpc_make_runnable(task);
-	if (!RPC_IS_ASYNC(task))
+	if (!is_async)
 		__rpc_execute(task);
 }