From 69df9d5993bd7dd7499ad0e98fe824147fbe5667 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 5 Nov 2009 20:59:47 -0800 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ipv4/ip_fragment.c | 7 ++++--- net/ipv6/reassembly.c | 13 ++++++------- 2 files changed, 10 insertions(+), 10 deletions(-) diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index 575f9bd51ccd..b007f8af6e1f 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -206,10 +206,11 @@ static void ip_expire(unsigned long arg) 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 da5bd0ed83df..dce699fb2672 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -208,18 +208,17 @@ static void ip6_frag_expire(unsigned long data) fq_kill(fq); net = container_of(fq->q.net, struct net, ipv6.frags); - dev = dev_get_by_index(net, fq->iif); + rcu_read_lock(); + dev = dev_get_by_index_rcu(net, fq->iif); if (!dev) - goto out; + goto out_rcu_unlock; - rcu_read_lock(); 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 @@ static void ip6_frag_expire(unsigned long data) */ 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); } -- 2.20.1