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tun: avoid unnecessary READ_ONCE in tun_net_xmit

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The statement no longer serves a purpose.

Commit fa35864e0b ("tuntap: Fix for a race in accessing numqueues")
added the ACCESS_ONCE to avoid a race condition with skb_queue_len.

Commit 436accebb5 ("tuntap: remove unnecessary sk_receive_queue
length check during xmit") removed the affected skb_queue_len check.

Commit 96f8406162 ("tun: add eBPF based queue selection method")
split the function, reading the field a second time in the callee.
The temp variable is now only read once, so just remove it.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Willem de Bruijn 2017-12-05 22:11:17 -05:00 committed by David S. Miller
parent d9b8693783
commit cc166427dc
1 changed files with 1 additions and 3 deletions
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4
drivers/net/tun.c
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@ -990,14 +990,12 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
struct tun_struct *tun = netdev_priv(dev);
int txq = skb->queue_mapping;
struct tun_file *tfile;
u32 numqueues = 0;
rcu_read_lock();
tfile = rcu_dereference(tun->tfiles[txq]);
numqueues = READ_ONCE(tun->numqueues);
/* Drop packet if interface is not attached */
if (txq >= numqueues)
if (txq >= tun->numqueues)
goto drop;
if (!rcu_dereference(tun->steering_prog))