ipv4: pass current value of rt_genid into rt_hash

Basically, there is no difference to atomic_read internally or pass it as
a parameter as rt_hash is inline.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/route.c

@@ -256,11 +256,12 @@ static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
 #define RT_CACHE_STAT_INC(field) \
 	(__raw_get_cpu_var(rt_cache_stat).field++)
 
-static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx)
+static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
+		int genid)
 {
 	return jhash_3words((__force u32)(__be32)(daddr),
 			    (__force u32)(__be32)(saddr),
-			    idx, atomic_read(&rt_genid))
+			    idx, genid)
 		& rt_hash_mask;
 }
 
@@ -1180,7 +1181,8 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
 
 	for (i = 0; i < 2; i++) {
 		for (k = 0; k < 2; k++) {
-			unsigned hash = rt_hash(daddr, skeys[i], ikeys[k]);
+			unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
+						atomic_read(&rt_genid));
 
 			rthp=&rt_hash_table[hash].chain;
 
@@ -1295,7 +1297,8 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
 		} else if ((rt->rt_flags & RTCF_REDIRECTED) ||
 			   rt->u.dst.expires) {
 			unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
-						rt->fl.oif);
+						rt->fl.oif,
+						atomic_read(&rt_genid));
 #if RT_CACHE_DEBUG >= 1
 			printk(KERN_DEBUG "ipv4_negative_advice: redirect to "
 					  NIPQUAD_FMT "/%02x dropped\n",
@@ -1444,7 +1447,8 @@ unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
 
 	for (k = 0; k < 2; k++) {
 		for (i = 0; i < 2; i++) {
-			unsigned hash = rt_hash(daddr, skeys[i], ikeys[k]);
+			unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
+						atomic_read(&rt_genid));
 
 			rcu_read_lock();
 			for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
@@ -1709,7 +1713,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	RT_CACHE_STAT_INC(in_slow_mc);
 
 	in_dev_put(in_dev);
-	hash = rt_hash(daddr, saddr, dev->ifindex);
+	hash = rt_hash(daddr, saddr, dev->ifindex, atomic_read(&rt_genid));
 	return rt_intern_hash(hash, rth, &skb->rtable);
 
 e_nobufs:
@@ -1870,7 +1874,7 @@ static int ip_mkroute_input(struct sk_buff *skb,
 		return err;
 
 	/* put it into the cache */
-	hash = rt_hash(daddr, saddr, fl->iif);
+	hash = rt_hash(daddr, saddr, fl->iif, atomic_read(&rt_genid));
 	return rt_intern_hash(hash, rth, &skb->rtable);
 }
 
@@ -2026,7 +2030,7 @@ out:	return err;
 		rth->rt_flags 	&= ~RTCF_LOCAL;
 	}
 	rth->rt_type	= res.type;
-	hash = rt_hash(daddr, saddr, fl.iif);
+	hash = rt_hash(daddr, saddr, fl.iif, atomic_read(&rt_genid));
 	err = rt_intern_hash(hash, rth, &skb->rtable);
 	goto done;
 
@@ -2077,7 +2081,7 @@ int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 
 	net = dev_net(dev);
 	tos &= IPTOS_RT_MASK;
-	hash = rt_hash(daddr, saddr, iif);
+	hash = rt_hash(daddr, saddr, iif, atomic_read(&rt_genid));
 
 	rcu_read_lock();
 	for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
@@ -2266,7 +2270,8 @@ static int ip_mkroute_output(struct rtable **rp,
 	int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
 	unsigned hash;
 	if (err == 0) {
-		hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif);
+		hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
+			       atomic_read(&rt_genid));
 		err = rt_intern_hash(hash, rth, rp);
 	}
 
@@ -2478,7 +2483,8 @@ int __ip_route_output_key(struct net *net, struct rtable **rp,
 	unsigned hash;
 	struct rtable *rth;
 
-	hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif);
+	hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif,
+		       atomic_read(&rt_genid));
 
 	rcu_read_lock_bh();
 	for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;