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>

5 files changed, 35 insertions, 22 deletions

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 4bce5a2830aa..4a049449305f 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -254,9 +254,10 @@ static inline bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
 
         /* Limit if icmp type is enabled in ratemask. */
         if ((1 << type) & net->ipv4.sysctl_icmp_ratemask) {
-                struct inet_peer *peer = rt_get_peer_create(rt, fl4->daddr);
+                struct inet_peer *peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, 1);
                 rc = inet_peer_xrlim_allow(peer,
                                            net->ipv4.sysctl_icmp_ratelimit);
+                inet_putpeer(peer);
         }
 out:
         return rc;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 78d81543766d..e376354dcb65 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1289,20 +1289,15 @@ static void ip_select_fb_ident(struct iphdr *iph)
 
 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
 {
-        struct rtable *rt = (struct rtable *) dst;
-
-        if (rt && !(rt->dst.flags & DST_NOPEER)) {
-                struct inet_peer *peer = rt_get_peer_create(rt, rt->rt_dst);
+        struct net *net = dev_net(dst->dev);
+        struct inet_peer *peer;
 
-                /* If peer is attached to destination, it is never detached,
-                   so that we need not to grab a lock to dereference it.
-                 */
-                if (peer) {
-                        iph->id = htons(inet_getid(peer, more));
-                        return;
-                }
-        } else if (!rt)
-                pr_debug("rt_bind_peer(0) @%p\n", __builtin_return_address(0));
+        peer = inet_getpeer_v4(net->ipv4.peers, iph->daddr, 1);
+        if (peer) {
+                iph->id = htons(inet_getid(peer, more));
+                inet_putpeer(peer);
+                return;
+        }
 
         ip_select_fb_ident(iph);
 }
@@ -1492,6 +1487,7 @@ void ip_rt_send_redirect(struct sk_buff *skb)
         struct rtable *rt = skb_rtable(skb);
         struct in_device *in_dev;
         struct inet_peer *peer;
+        struct net *net;
         int log_martians;
 
         rcu_read_lock();
@@ -1503,7 +1499,8 @@ void ip_rt_send_redirect(struct sk_buff *skb)
         log_martians = IN_DEV_LOG_MARTIANS(in_dev);
         rcu_read_unlock();
 
-        peer = rt_get_peer_create(rt, rt->rt_dst);
+        net = dev_net(rt->dst.dev);
+        peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
         if (!peer) {
                 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
                 return;
@@ -1520,7 +1517,7 @@ void ip_rt_send_redirect(struct sk_buff *skb)
          */
         if (peer->rate_tokens >= ip_rt_redirect_number) {
                 peer->rate_last = jiffies;
-                return;
+                goto out_put_peer;
         }
 
         /* Check for load limit; set rate_last to the latest sent
@@ -1541,6 +1538,8 @@ void ip_rt_send_redirect(struct sk_buff *skb)
                                              &rt->rt_dst, &rt->rt_gateway);
 #endif
         }
+out_put_peer:
+        inet_putpeer(peer);
 }
 
 static int ip_error(struct sk_buff *skb)
@@ -1583,7 +1582,7 @@ static int ip_error(struct sk_buff *skb)
                 break;
         }
 
-        peer = rt_get_peer_create(rt, rt->rt_dst);
+        peer = inet_getpeer_v4(net->ipv4.peers, ip_hdr(skb)->saddr, 1);
 
         send = true;
         if (peer) {
@@ -1596,6 +1595,7 @@ static int ip_error(struct sk_buff *skb)
                         peer->rate_tokens -= ip_rt_error_cost;
                 else
                         send = false;
+                inet_putpeer(peer);
         }
         if (send)
                 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index c7da1422cbde..a113f7d7e938 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -194,8 +194,10 @@ static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
                 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 c6af5963a202..5b2d63ed793e 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -466,13 +466,15 @@ int ip6_forward(struct sk_buff *skb)
                 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 @@ void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt)
         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 69a6330dea91..0fddd571400d 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1486,6 +1486,7 @@ void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
         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 @@ void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
                           "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) {