ifb: RCU locking avoids touching dev refcount

Avoids touching dev refcount in hotpath

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
index 030913f8bd26..69c25668dd63 100644
--- a/drivers/net/ifb.c
+++ b/drivers/net/ifb.c
@@ -98,13 +98,15 @@ static void ri_tasklet(unsigned long dev)
                 stats->tx_packets++;
                 stats->tx_bytes +=skb->len;
 
-                skb->dev = dev_get_by_index(&init_net, skb->iif);
+                rcu_read_lock();
+                skb->dev = dev_get_by_index_rcu(&init_net, skb->iif);
                 if (!skb->dev) {
+                        rcu_read_unlock();
                         dev_kfree_skb(skb);
                         stats->tx_dropped++;
                         break;
                 }
-                dev_put(skb->dev);
+                rcu_read_unlock();
                 skb->iif = _dev->ifindex;
 
                 if (from & AT_EGRESS) {