net: Abstract default MTU metric calculation behind an accessor.
Like RTAX_ADVMSS, make the default calculation go through a dst_ops
method rather than caching the computation in the routing cache
entries.
Now dst metrics are pretty much left as-is when new entries are
created, thus optimizing metric sharing becomes a real possibility.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index d9cb832..e7efb26 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -77,6 +77,7 @@
static struct rt6_info * ip6_rt_copy(struct rt6_info *ort);
static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
static unsigned int ip6_default_advmss(const struct dst_entry *dst);
+static unsigned int ip6_default_mtu(const struct dst_entry *dst);
static struct dst_entry *ip6_negative_advice(struct dst_entry *);
static void ip6_dst_destroy(struct dst_entry *);
static void ip6_dst_ifdown(struct dst_entry *,
@@ -105,6 +106,7 @@
.gc_thresh = 1024,
.check = ip6_dst_check,
.default_advmss = ip6_default_advmss,
+ .default_mtu = ip6_default_mtu,
.destroy = ip6_dst_destroy,
.ifdown = ip6_dst_ifdown,
.negative_advice = ip6_negative_advice,
@@ -937,8 +939,6 @@
}
}
-static int ipv6_get_mtu(struct net_device *dev);
-
static unsigned int ip6_default_advmss(const struct dst_entry *dst)
{
struct net_device *dev = dst->dev;
@@ -961,6 +961,20 @@
return mtu;
}
+static unsigned int ip6_default_mtu(const struct dst_entry *dst)
+{
+ unsigned int mtu = IPV6_MIN_MTU;
+ struct inet6_dev *idev;
+
+ rcu_read_lock();
+ idev = __in6_dev_get(dst->dev);
+ if (idev)
+ mtu = idev->cnf.mtu6;
+ rcu_read_unlock();
+
+ return mtu;
+}
+
static struct dst_entry *icmp6_dst_gc_list;
static DEFINE_SPINLOCK(icmp6_dst_lock);
@@ -995,7 +1009,6 @@
rt->rt6i_nexthop = neigh;
atomic_set(&rt->dst.__refcnt, 1);
dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 255);
- dst_metric_set(&rt->dst, RTAX_MTU, ipv6_get_mtu(rt->rt6i_dev));
rt->dst.output = ip6_output;
#if 0 /* there's no chance to use these for ndisc */
@@ -1094,19 +1107,6 @@
Remove it only when all the things will work!
*/
-static int ipv6_get_mtu(struct net_device *dev)
-{
- int mtu = IPV6_MIN_MTU;
- struct inet6_dev *idev;
-
- rcu_read_lock();
- idev = __in6_dev_get(dev);
- if (idev)
- mtu = idev->cnf.mtu6;
- rcu_read_unlock();
- return mtu;
-}
-
int ip6_dst_hoplimit(struct dst_entry *dst)
{
int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
@@ -1315,8 +1315,6 @@
}
}
- if (!dst_mtu(&rt->dst))
- dst_metric_set(&rt->dst, RTAX_MTU, ipv6_get_mtu(dev));
rt->dst.dev = dev;
rt->rt6i_idev = idev;
rt->rt6i_table = table;
@@ -1541,8 +1539,6 @@
ipv6_addr_copy(&nrt->rt6i_gateway, (struct in6_addr*)neigh->primary_key);
nrt->rt6i_nexthop = neigh_clone(neigh);
- /* Reset pmtu, it may be better */
- dst_metric_set(&nrt->dst, RTAX_MTU, ipv6_get_mtu(neigh->dev));
if (ip6_ins_rt(nrt))
goto out;
@@ -1971,7 +1967,6 @@
rt->dst.output = ip6_output;
rt->rt6i_dev = net->loopback_dev;
rt->rt6i_idev = idev;
- dst_metric_set(&rt->dst, RTAX_MTU, ipv6_get_mtu(rt->rt6i_dev));
dst_metric_set(&rt->dst, RTAX_HOPLIMIT, -1);
rt->dst.obsolete = -1;