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>
This commit is contained in:
Michael S. Tsirkin 2013-10-06 21:25:12 +03:00 committed by David S. Miller
parent 66e358a847
commit 5c0c52c910

View File

@ -1293,7 +1293,8 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
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 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
break;
}
current->state = TASK_RUNNING;
if (unlikely(!noblock))
if (unlikely(!noblock)) {
current->state = TASK_RUNNING;
remove_wait_queue(&tfile->wq.wait, &wait);
}
return ret;
}