ip_frag: dont touch device refcount
When sending fragmentation expiration ICMP V4/V6 messages,
we can avoid touching device refcount, thanks to RCU
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index 575f9bd..b007f8a 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -206,10 +206,11 @@
struct sk_buff *head = qp->q.fragments;
/* Send an ICMP "Fragment Reassembly Timeout" message. */
- if ((head->dev = dev_get_by_index(net, qp->iif)) != NULL) {
+ rcu_read_lock();
+ head->dev = dev_get_by_index_rcu(net, qp->iif);
+ if (head->dev)
icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
- dev_put(head->dev);
- }
+ rcu_read_unlock();
}
out:
spin_unlock(&qp->q.lock);
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index da5bd0e..dce699f 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -208,18 +208,17 @@
fq_kill(fq);
net = container_of(fq->q.net, struct net, ipv6.frags);
- dev = dev_get_by_index(net, fq->iif);
- if (!dev)
- goto out;
-
rcu_read_lock();
+ dev = dev_get_by_index_rcu(net, fq->iif);
+ if (!dev)
+ goto out_rcu_unlock;
+
IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
- rcu_read_unlock();
/* Don't send error if the first segment did not arrive. */
if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments)
- goto out;
+ goto out_rcu_unlock;
/*
But use as source device on which LAST ARRIVED
@@ -228,9 +227,9 @@
*/
fq->q.fragments->dev = dev;
icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev);
+out_rcu_unlock:
+ rcu_read_unlock();
out:
- if (dev)
- dev_put(dev);
spin_unlock(&fq->q.lock);
fq_put(fq);
}