SUNRPC: Don't start a timer on an already queued rpc task

Move the test for whether a task is already queued to prevent
corruption of the timer list in __rpc_sleep_on_priority_timeout().

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

diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 6eff141..7eba20a 100644 (file)
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -204,10 +204,6 @@ static void __rpc_add_wait_queue(struct rpc_wait_queue *queue,
                struct rpc_task *task,
                unsigned char queue_priority)
 {
-       WARN_ON_ONCE(RPC_IS_QUEUED(task));
-       if (RPC_IS_QUEUED(task))
-               return;
-
        INIT_LIST_HEAD(&task->u.tk_wait.timer_list);
        if (RPC_IS_PRIORITY(queue))
                __rpc_add_wait_queue_priority(queue, task, queue_priority);
@@ -382,7 +378,7 @@ static void rpc_make_runnable(struct workqueue_struct *wq,
  * NB: An RPC task will only receive interrupt-driven events as long
  * as it's on a wait queue.
  */
-static void __rpc_sleep_on_priority(struct rpc_wait_queue *q,
+static void __rpc_do_sleep_on_priority(struct rpc_wait_queue *q,
                struct rpc_task *task,
                unsigned char queue_priority)
 {
@@ -395,12 +391,23 @@ static void __rpc_sleep_on_priority(struct rpc_wait_queue *q,
 
 }
 
+static void __rpc_sleep_on_priority(struct rpc_wait_queue *q,
+               struct rpc_task *task,
+               unsigned char queue_priority)
+{
+       if (WARN_ON_ONCE(RPC_IS_QUEUED(task)))
+               return;
+       __rpc_do_sleep_on_priority(q, task, queue_priority);
+}
+
 static void __rpc_sleep_on_priority_timeout(struct rpc_wait_queue *q,
                struct rpc_task *task, unsigned long timeout,
                unsigned char queue_priority)
 {
+       if (WARN_ON_ONCE(RPC_IS_QUEUED(task)))
+               return;
        if (time_is_after_jiffies(timeout)) {
-               __rpc_sleep_on_priority(q, task, queue_priority);
+               __rpc_do_sleep_on_priority(q, task, queue_priority);
                __rpc_add_timer(q, task, timeout);
        } else
                task->tk_status = -ETIMEDOUT;