tun: don't look at current when non-blocking
We play with a wait queue even if socket is
non blocking. This is an obvious waste.
Besides, it will prevent calling the non blocking
variant when current is not valid.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 807815f..7cb105c 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1293,7 +1293,8 @@
if (unlikely(!noblock))
add_wait_queue(&tfile->wq.wait, &wait);
while (len) {
- current->state = TASK_INTERRUPTIBLE;
+ if (unlikely(!noblock))
+ current->state = TASK_INTERRUPTIBLE;
/* Read frames from the queue */
if (!(skb = skb_dequeue(&tfile->socket.sk->sk_receive_queue))) {
@@ -1320,9 +1321,10 @@
break;
}
- current->state = TASK_RUNNING;
- if (unlikely(!noblock))
+ if (unlikely(!noblock)) {
+ current->state = TASK_RUNNING;
remove_wait_queue(&tfile->wq.wait, &wait);
+ }
return ret;
}