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ip_frag: dont touch device refcount

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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>
This commit is contained in:
Eric Dumazet
2009-11-05 20:59:47 -08:00
committed by David S. Miller
parent bd27a8750c
commit 69df9d5993
2 changed files with 11 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
net/ipv4/ip_fragment.c
View File

@@ -206,10 +206,11 @@ static void ip_expire(unsigned long arg)
struct sk_buff *head = qp->q.fragments; struct sk_buff *head = qp->q.fragments;
/* Send an ICMP "Fragment Reassembly Timeout" message. */ /* 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); icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
dev_put(head->dev); rcu_read_unlock();
}
} }
out: out:
spin_unlock(&qp->q.lock); spin_unlock(&qp->q.lock);

15
net/ipv6/reassembly.c
View File

@@ -208,18 +208,17 @@ static void ip6_frag_expire(unsigned long data)
fq_kill(fq); fq_kill(fq);
net = container_of(fq->q.net, struct net, ipv6.frags); 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(); 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_REASMTIMEOUT);
IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); 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. */ /* Don't send error if the first segment did not arrive. */
if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments) 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 But use as source device on which LAST ARRIVED
@@ -228,9 +227,9 @@ static void ip6_frag_expire(unsigned long data)
*/ */
fq->q.fragments->dev = dev; fq->q.fragments->dev = dev;
icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev); icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev);
out_rcu_unlock:
rcu_read_unlock();
out: out:
if (dev)
dev_put(dev);
spin_unlock(&fq->q.lock); spin_unlock(&fq->q.lock);
fq_put(fq); fq_put(fq);
} }