ipv6: some RCU conversions

ICMP and ND are not fast path, but still we can avoid changing idev
refcount, using RCU.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 11900417b1cc0daea102552858a07a1efb179e67..2b59154c65d3127f065803b209a584cd81651783 100644 (file)
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -490,7 +490,8 @@ void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
                goto out_dst_release;
        }
 
-       idev = in6_dev_get(skb->dev);
+       rcu_read_lock();
+       idev = __in6_dev_get(skb->dev);
 
        err = ip6_append_data(sk, icmpv6_getfrag, &msg,
                              len + sizeof(struct icmp6hdr),
@@ -500,19 +501,16 @@ void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
        if (err) {
                ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
                ip6_flush_pending_frames(sk);
-               goto out_put;
+       } else {
+               err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
+                                                len + sizeof(struct icmp6hdr));
        }
-       err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, len + sizeof(struct icmp6hdr));
-
-out_put:
-       if (likely(idev != NULL))
-               in6_dev_put(idev);
+       rcu_read_unlock();
 out_dst_release:
        dst_release(dst);
 out:
        icmpv6_xmit_unlock(sk);
 }
-
 EXPORT_SYMBOL(icmpv6_send);
 
 static void icmpv6_echo_reply(struct sk_buff *skb)
@@ -569,7 +567,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
        if (hlimit < 0)
                hlimit = ip6_dst_hoplimit(dst);
 
-       idev = in6_dev_get(skb->dev);
+       idev = __in6_dev_get(skb->dev);
 
        msg.skb = skb;
        msg.offset = 0;
@@ -583,13 +581,10 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
        if (err) {
                ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
                ip6_flush_pending_frames(sk);
-               goto out_put;
+       } else {
+               err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
+                                                skb->len + sizeof(struct icmp6hdr));
        }
-       err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, skb->len + sizeof(struct icmp6hdr));
-
-out_put:
-       if (likely(idev != NULL))
-               in6_dev_put(idev);
        dst_release(dst);
 out:
        icmpv6_xmit_unlock(sk);

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 9da6e02eaaebffdb47949ff0c0fbf43dc1b9a208..1f52dd2576312bd33e242d445eb5510f993f529d 100644 (file)
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -533,7 +533,8 @@ void ndisc_send_skb(struct sk_buff *skb,
 
        skb_dst_set(skb, dst);
 
-       idev = in6_dev_get(dst->dev);
+       rcu_read_lock();
+       idev = __in6_dev_get(dst->dev);
        IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
 
        err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
@@ -543,8 +544,7 @@ void ndisc_send_skb(struct sk_buff *skb,
                ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
        }
 
-       if (likely(idev != NULL))
-               in6_dev_put(idev);
+       rcu_read_unlock();
 }
 
 EXPORT_SYMBOL(ndisc_send_skb);
@@ -1039,7 +1039,7 @@ static void ndisc_recv_rs(struct sk_buff *skb)
        if (skb->len < sizeof(*rs_msg))
                return;
 
-       idev = in6_dev_get(skb->dev);
+       idev = __in6_dev_get(skb->dev);
        if (!idev) {
                if (net_ratelimit())
                        ND_PRINTK1("ICMP6 RS: can't find in6 device\n");
@@ -1080,7 +1080,7 @@ static void ndisc_recv_rs(struct sk_buff *skb)
                neigh_release(neigh);
        }
 out:
-       in6_dev_put(idev);
+       return;
 }
 
 static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
@@ -1179,7 +1179,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
         *      set the RA_RECV flag in the interface
         */
 
-       in6_dev = in6_dev_get(skb->dev);
+       in6_dev = __in6_dev_get(skb->dev);
        if (in6_dev == NULL) {
                ND_PRINTK0(KERN_ERR
                           "ICMPv6 RA: can't find inet6 device for %s.\n",
@@ -1188,7 +1188,6 @@ static void ndisc_router_discovery(struct sk_buff *skb)
        }
 
        if (!ndisc_parse_options(opt, optlen, &ndopts)) {
-               in6_dev_put(in6_dev);
                ND_PRINTK2(KERN_WARNING
                           "ICMP6 RA: invalid ND options\n");
                return;
@@ -1255,7 +1254,6 @@ static void ndisc_router_discovery(struct sk_buff *skb)
                        ND_PRINTK0(KERN_ERR
                                   "ICMPv6 RA: %s() failed to add default route.\n",
                                   __func__);
-                       in6_dev_put(in6_dev);
                        return;
                }
 
@@ -1265,7 +1263,6 @@ static void ndisc_router_discovery(struct sk_buff *skb)
                                   "ICMPv6 RA: %s() got default router without neighbour.\n",
                                   __func__);
                        dst_release(&rt->dst);
-                       in6_dev_put(in6_dev);
                        return;
                }
                neigh->flags |= NTF_ROUTER;
@@ -1422,7 +1419,6 @@ out:
                dst_release(&rt->dst);
        else if (neigh)
                neigh_release(neigh);
-       in6_dev_put(in6_dev);
 }
 
 static void ndisc_redirect_rcv(struct sk_buff *skb)
@@ -1481,13 +1477,11 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
                return;
        }
 
-       in6_dev = in6_dev_get(skb->dev);
+       in6_dev = __in6_dev_get(skb->dev);
        if (!in6_dev)
                return;
-       if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) {
-               in6_dev_put(in6_dev);
+       if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
                return;
-       }
 
        /* RFC2461 8.1:
         *      The IP source address of the Redirect MUST be the same as the current
@@ -1497,7 +1491,6 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
        if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) {
                ND_PRINTK2(KERN_WARNING
                           "ICMPv6 Redirect: invalid ND options\n");
-               in6_dev_put(in6_dev);
                return;
        }
        if (ndopts.nd_opts_tgt_lladdr) {
@@ -1506,7 +1499,6 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
                if (!lladdr) {
                        ND_PRINTK2(KERN_WARNING
                                   "ICMPv6 Redirect: invalid link-layer address length\n");
-                       in6_dev_put(in6_dev);
                        return;
                }
        }
@@ -1518,7 +1510,6 @@ static void ndisc_redirect_rcv(struct sk_buff *skb)
                             on_link);
                neigh_release(neigh);
        }
-       in6_dev_put(in6_dev);
 }
 
 void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
@@ -1651,7 +1642,8 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
                                             csum_partial(icmph, len, 0));
 
        skb_dst_set(buff, dst);
-       idev = in6_dev_get(dst->dev);
+       rcu_read_lock();
+       idev = __in6_dev_get(dst->dev);
        IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUT, skb->len);
        err = NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, buff, NULL, dst->dev,
                      dst_output);
@@ -1660,8 +1652,7 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
                ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
        }
 
-       if (likely(idev != NULL))
-               in6_dev_put(idev);
+       rcu_read_unlock();
        return;
 
 release: