inet: Minimize use of cached route inetpeer.

Only use it in the absolutely required cases:

1) COW'ing metrics

2) ipv4 PMTU

3) ipv4 redirects

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index c7da142..a113f7d 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -194,8 +194,10 @@
 		if (rt->rt6i_dst.plen < 128)
 			tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
 
-		peer = rt6_get_peer_create(rt);
+		peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
 		res = inet_peer_xrlim_allow(peer, tmo);
+		if (peer)
+			inet_putpeer(peer);
 	}
 	dst_release(dst);
 	return res;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index c6af596..5b2d63e 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -466,13 +466,15 @@
 		else
 			target = &hdr->daddr;
 
-		peer = rt6_get_peer_create(rt);
+		peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
 
 		/* Limit redirects both by destination (here)
 		   and by source (inside ndisc_send_redirect)
 		 */
 		if (inet_peer_xrlim_allow(peer, 1*HZ))
 			ndisc_send_redirect(skb, target);
+		if (peer)
+			inet_putpeer(peer);
 	} else {
 		int addrtype = ipv6_addr_type(&hdr->saddr);
 
@@ -592,10 +594,14 @@
 	int old, new;
 
 	if (rt && !(rt->dst.flags & DST_NOPEER)) {
-		struct inet_peer *peer = rt6_get_peer_create(rt);
+		struct inet_peer *peer;
+		struct net *net;
 
+		net = dev_net(rt->dst.dev);
+		peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
 		if (peer) {
 			fhdr->identification = htonl(inet_getid(peer, 0));
+			inet_putpeer(peer);
 			return;
 		}
 	}
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 69a6330..0fddd57 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1486,6 +1486,7 @@
 	int rd_len;
 	int err;
 	u8 ha_buf[MAX_ADDR_LEN], *ha = NULL;
+	bool ret;
 
 	if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
 		ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
@@ -1519,8 +1520,11 @@
 			  "Redirect: destination is not a neighbour\n");
 		goto release;
 	}
-	peer = rt6_get_peer_create(rt);
-	if (!inet_peer_xrlim_allow(peer, 1*HZ))
+	peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
+	ret = inet_peer_xrlim_allow(peer, 1*HZ);
+	if (peer)
+		inet_putpeer(peer);
+	if (!ret)
 		goto release;
 
 	if (dev->addr_len) {