Commit cc166427 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by David S. Miller

tun: avoid unnecessary READ_ONCE in tun_net_xmit

The statement no longer serves a purpose.

Commit fa35864e ("tuntap: Fix for a race in accessing numqueues")
added the ACCESS_ONCE to avoid a race condition with skb_queue_len.

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

Commit 96f84061 ("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: default avatarWillem de Bruijn <willemb@google.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d9b86937
...@@ -990,14 +990,12 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev) ...@@ -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); struct tun_struct *tun = netdev_priv(dev);
int txq = skb->queue_mapping; int txq = skb->queue_mapping;
struct tun_file *tfile; struct tun_file *tfile;
u32 numqueues = 0;
rcu_read_lock(); rcu_read_lock();
tfile = rcu_dereference(tun->tfiles[txq]); tfile = rcu_dereference(tun->tfiles[txq]);
numqueues = READ_ONCE(tun->numqueues);
/* Drop packet if interface is not attached */ /* Drop packet if interface is not attached */
if (txq >= numqueues) if (txq >= tun->numqueues)
goto drop; goto drop;
if (!rcu_dereference(tun->steering_prog)) if (!rcu_dereference(tun->steering_prog))
......
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