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netfilter: ipt_MASQUERADE: remove redundant rwlock

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The lock "protects" an assignment and a comparision of an integer.
When the caller of device_cmp() evaluates the result, nat->masq_index
may already have been changed (regardless if the lock is there or not).

So, the lock either has to be held during nf_ct_iterate_cleanup(),
or can be removed.

This does the latter.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Florian Westphal 2009-06-05 13:26:21 +02:00 committed by Patrick McHardy
parent 10662aa308
commit 17f2f52be0
1 changed files with 1 additions and 11 deletions
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12
net/ipv4/netfilter/ipt_MASQUERADE.c
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@ -27,9 +27,6 @@ MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("Xtables: automatic-address SNAT");
/* Lock protects masq region inside conntrack */
static DEFINE_RWLOCK(masq_lock);
/* FIXME: Multiple targets. --RR */
static bool masquerade_tg_check(const struct xt_tgchk_param *par)
{
@ -79,9 +76,7 @@ masquerade_tg(struct sk_buff *skb, const struct xt_target_param *par)
return NF_DROP;
}
write_lock_bh(&masq_lock);
nat->masq_index = par->out->ifindex;
write_unlock_bh(&masq_lock);
/* Transfer from original range. */
newrange = ((struct nf_nat_range)
@ -97,16 +92,11 @@ static int
device_cmp(struct nf_conn *i, void *ifindex)
{
const struct nf_conn_nat *nat = nfct_nat(i);
int ret;
if (!nat)
return 0;
read_lock_bh(&masq_lock);
ret = (nat->masq_index == (int)(long)ifindex);
read_unlock_bh(&masq_lock);
return ret;
return nat->masq_index == (int)(long)ifindex;
}
static int masq_device_event(struct notifier_block *this,