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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-06-07 03:17:10 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-06-07 21:25:21 -0700 |
| commit | 9a57a9d291980302b4a3184fbc47dbddac71903e (patch) | |
| tree | f7e28ced28e4615074ceaf6ab4750a9630cdba95 /net/ipv4/igmp.c | |
| parent | 66018506e15bea62de4eefc3298f170b4bfcf5ef (diff) | |
| download | linux-9a57a9d291980302b4a3184fbc47dbddac71903e.tar.bz2 | |
igmp: avoid two atomic ops in igmp_rcv()
in_dev_get() -> __in_dev_get_rcu() in a rcu protected function.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/igmp.c')
| -rw-r--r-- | net/ipv4/igmp.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 250cb5e1af48..3294f547c481 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -916,18 +916,19 @@ static void igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb, read_unlock(&in_dev->mc_list_lock); } +/* called in rcu_read_lock() section */ int igmp_rcv(struct sk_buff *skb) { /* This basically follows the spec line by line -- see RFC1112 */ struct igmphdr *ih; - struct in_device *in_dev = in_dev_get(skb->dev); + struct in_device *in_dev = __in_dev_get_rcu(skb->dev); int len = skb->len; if (in_dev == NULL) goto drop; if (!pskb_may_pull(skb, sizeof(struct igmphdr))) - goto drop_ref; + goto drop; switch (skb->ip_summed) { case CHECKSUM_COMPLETE: @@ -937,7 +938,7 @@ int igmp_rcv(struct sk_buff *skb) case CHECKSUM_NONE: skb->csum = 0; if (__skb_checksum_complete(skb)) - goto drop_ref; + goto drop; } ih = igmp_hdr(skb); @@ -957,7 +958,6 @@ int igmp_rcv(struct sk_buff *skb) break; case IGMP_PIM: #ifdef CONFIG_IP_PIMSM_V1 - in_dev_put(in_dev); return pim_rcv_v1(skb); #endif case IGMPV3_HOST_MEMBERSHIP_REPORT: @@ -971,8 +971,6 @@ int igmp_rcv(struct sk_buff *skb) break; } -drop_ref: - in_dev_put(in_dev); drop: kfree_skb(skb); return 0; |