Commit c002496b authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'ipv6-loopback' 



Eric Dumazet says:

====================
ipv6: remove addrconf reliance on loopback

Second patch in this series removes IPv6 requirement about the netns
loopback device being the last device being dismantled.

This was needed because rt6_uncached_list_flush_dev()
and ip6_dst_ifdown() had to switch dst dev to a known
device (loopback).

Instead of loopback, we can use the (hidden) blackhole_netdev
which is also always there.

This will allow future simplfications of netdev_run_to()
and other parts of the stack like default_device_exit_batch().

Last two patches are optimizations for both IP families.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 926eae60 29e5375d

include/net/ip6_fib.h

+1 −2
Original line number Diff line number Diff line
@@ -367,9 +367,8 @@ struct rt6_statistics { 
	__u32		fib_rt_cache;		/* cached rt entries in exception table */

	__u32		fib_discarded_routes;	/* total number of routes delete */



	/* The following stats are not protected by any lock */

	/* The following stat is not protected by any lock */

	atomic_t	fib_rt_alloc;		/* total number of routes alloced */

	atomic_t	fib_rt_uncache;		/* rt entries in uncached list */

};



#define RTN_TL_ROOT	0x0001

net/ipv4/route.c

+9 −3
Original line number Diff line number Diff line
@@ -1485,6 +1485,7 @@ static bool rt_cache_route(struct fib_nh_common *nhc, struct rtable *rt) 
struct uncached_list {

	spinlock_t		lock;

	struct list_head	head;

	struct list_head	quarantine;

};



static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt_uncached_list);
@@ -1506,7 +1507,7 @@ void rt_del_uncached_list(struct rtable *rt) 
		struct uncached_list *ul = rt->rt_uncached_list;



		spin_lock_bh(&ul->lock);

		list_del(&rt->rt_uncached);

		list_del_init(&rt->rt_uncached);

		spin_unlock_bh(&ul->lock);

	}

}
@@ -1521,20 +1522,24 @@ static void ipv4_dst_destroy(struct dst_entry *dst) 


void rt_flush_dev(struct net_device *dev)

{

	struct rtable *rt;

	struct rtable *rt, *safe;

	int cpu;



	for_each_possible_cpu(cpu) {

		struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);



		if (list_empty(&ul->head))

			continue;



		spin_lock_bh(&ul->lock);

		list_for_each_entry(rt, &ul->head, rt_uncached) {

		list_for_each_entry_safe(rt, safe, &ul->head, rt_uncached) {

			if (rt->dst.dev != dev)

				continue;

			rt->dst.dev = blackhole_netdev;

			dev_replace_track(dev, blackhole_netdev,

					  &rt->dst.dev_tracker,

					  GFP_ATOMIC);

			list_move(&rt->rt_uncached, &ul->quarantine);

		}

		spin_unlock_bh(&ul->lock);

	}
@@ -3706,6 +3711,7 @@ int __init ip_rt_init(void) 
		struct uncached_list *ul = &per_cpu(rt_uncached_list, cpu);



		INIT_LIST_HEAD(&ul->head);

		INIT_LIST_HEAD(&ul->quarantine);

		spin_lock_init(&ul->lock);

	}

#ifdef CONFIG_IP_ROUTE_CLASSID

net/ipv6/addrconf.c

+32 −46
Original line number Diff line number Diff line
@@ -372,7 +372,7 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) 


	ASSERT_RTNL();



	if (dev->mtu < IPV6_MIN_MTU)

	if (dev->mtu < IPV6_MIN_MTU && dev != blackhole_netdev)

		return ERR_PTR(-EINVAL);



	ndev = kzalloc(sizeof(struct inet6_dev), GFP_KERNEL);
@@ -400,6 +400,7 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) 
	/* We refer to the device */

	dev_hold_track(dev, &ndev->dev_tracker, GFP_KERNEL);



	if (dev != blackhole_netdev) {

		if (snmp6_alloc_dev(ndev) < 0) {

			netdev_dbg(dev, "%s: cannot allocate memory for statistics\n",

				   __func__);
@@ -414,7 +415,7 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) 
				   __func__, dev->name);

			goto err_release;

		}



	}

	/* One reference from device. */

	refcount_set(&ndev->refcnt, 1);
@@ -445,15 +446,18 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) 


	ipv6_mc_init_dev(ndev);

	ndev->tstamp = jiffies;

	if (dev != blackhole_netdev) {

		err = addrconf_sysctl_register(ndev);

		if (err) {

			ipv6_mc_destroy_dev(ndev);

			snmp6_unregister_dev(ndev);

			goto err_release;

		}

	}

	/* protected by rtnl_lock */

	rcu_assign_pointer(dev->ip6_ptr, ndev);



	if (dev != blackhole_netdev) {

		/* Join interface-local all-node multicast group */

		ipv6_dev_mc_inc(dev, &in6addr_interfacelocal_allnodes);
@@ -463,7 +467,7 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) 
		/* Join all-router multicast group if forwarding is set */

		if (ndev->cnf.forwarding && (dev->flags & IFF_MULTICAST))

			ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);



	}

	return ndev;



err_release:
@@ -7233,26 +7237,8 @@ int __init addrconf_init(void) 
		goto out_nowq;

	}



	/* The addrconf netdev notifier requires that loopback_dev

	 * has it's ipv6 private information allocated and setup

	 * before it can bring up and give link-local addresses

	 * to other devices which are up.

	 *

	 * Unfortunately, loopback_dev is not necessarily the first

	 * entry in the global dev_base list of net devices.  In fact,

	 * it is likely to be the very last entry on that list.

	 * So this causes the notifier registry below to try and

	 * give link-local addresses to all devices besides loopback_dev

	 * first, then loopback_dev, which cases all the non-loopback_dev

	 * devices to fail to get a link-local address.

	 *

	 * So, as a temporary fix, allocate the ipv6 structure for

	 * loopback_dev first by hand.

	 * Longer term, all of the dependencies ipv6 has upon the loopback

	 * device and it being up should be removed.

	 */

	rtnl_lock();

	idev = ipv6_add_dev(init_net.loopback_dev);

	idev = ipv6_add_dev(blackhole_netdev);

	rtnl_unlock();

	if (IS_ERR(idev)) {

		err = PTR_ERR(idev);

net/ipv6/route.c

+22 −20
Original line number Diff line number Diff line
@@ -130,6 +130,7 @@ static struct fib6_info *rt6_get_route_info(struct net *net, 
struct uncached_list {

	spinlock_t		lock;

	struct list_head	head;

	struct list_head	quarantine;

};



static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
@@ -149,35 +150,34 @@ void rt6_uncached_list_del(struct rt6_info *rt) 
{

	if (!list_empty(&rt->rt6i_uncached)) {

		struct uncached_list *ul = rt->rt6i_uncached_list;

		struct net *net = dev_net(rt->dst.dev);



		spin_lock_bh(&ul->lock);

		list_del(&rt->rt6i_uncached);

		atomic_dec(&net->ipv6.rt6_stats->fib_rt_uncache);

		list_del_init(&rt->rt6i_uncached);

		spin_unlock_bh(&ul->lock);

	}

}



static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev)

static void rt6_uncached_list_flush_dev(struct net_device *dev)

{

	struct net_device *loopback_dev = net->loopback_dev;

	int cpu;



	if (dev == loopback_dev)

		return;



	for_each_possible_cpu(cpu) {

		struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);

		struct rt6_info *rt;

		struct rt6_info *rt, *safe;



		if (list_empty(&ul->head))

			continue;



		spin_lock_bh(&ul->lock);

		list_for_each_entry(rt, &ul->head, rt6i_uncached) {

		list_for_each_entry_safe(rt, safe, &ul->head, rt6i_uncached) {

			struct inet6_dev *rt_idev = rt->rt6i_idev;

			struct net_device *rt_dev = rt->dst.dev;

			bool handled = false;



			if (rt_idev->dev == dev) {

				rt->rt6i_idev = in6_dev_get(loopback_dev);

				rt->rt6i_idev = in6_dev_get(blackhole_netdev);

				in6_dev_put(rt_idev);

				handled = true;

			}



			if (rt_dev == dev) {
@@ -185,7 +185,11 @@ static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev) 
				dev_replace_track(rt_dev, blackhole_netdev,

						  &rt->dst.dev_tracker,

						  GFP_ATOMIC);

				handled = true;

			}

			if (handled)

				list_move(&rt->rt6i_uncached,

					  &ul->quarantine);

		}

		spin_unlock_bh(&ul->lock);

	}
@@ -373,13 +377,12 @@ static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 
{

	struct rt6_info *rt = (struct rt6_info *)dst;

	struct inet6_dev *idev = rt->rt6i_idev;

	struct net_device *loopback_dev =

		dev_net(dev)->loopback_dev;



	if (idev && idev->dev != loopback_dev) {

		struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);

		if (loopback_idev) {

			rt->rt6i_idev = loopback_idev;

	if (idev && idev->dev != blackhole_netdev) {

		struct inet6_dev *blackhole_idev = in6_dev_get(blackhole_netdev);



		if (blackhole_idev) {

			rt->rt6i_idev = blackhole_idev;

			in6_dev_put(idev);

		}

	}
@@ -2244,7 +2247,6 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 
			 * if caller sets RT6_LOOKUP_F_DST_NOREF flag.

			 */

			rt6_uncached_list_add(rt);

			atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);

			rcu_read_unlock();



			return rt;
@@ -3287,7 +3289,6 @@ struct dst_entry *icmp6_dst_alloc(struct net_device *dev, 
	 * do proper release of the net_device

	 */

	rt6_uncached_list_add(rt);

	atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);



	dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
@@ -4896,7 +4897,7 @@ void rt6_sync_down_dev(struct net_device *dev, unsigned long event) 
void rt6_disable_ip(struct net_device *dev, unsigned long event)

{

	rt6_sync_down_dev(dev, event);

	rt6_uncached_list_flush_dev(dev_net(dev), dev);

	rt6_uncached_list_flush_dev(dev);

	neigh_ifdown(&nd_tbl, dev);

}
@@ -6736,6 +6737,7 @@ int __init ip6_route_init(void) 
		struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);



		INIT_LIST_HEAD(&ul->head);

		INIT_LIST_HEAD(&ul->quarantine);

		spin_lock_init(&ul->lock);

	}

net/ipv6/xfrm6_policy.c

+0 −1
Original line number Diff line number Diff line
@@ -92,7 +92,6 @@ static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 
	xdst->u.rt6.rt6i_src = rt->rt6i_src;

	INIT_LIST_HEAD(&xdst->u.rt6.rt6i_uncached);

	rt6_uncached_list_add(&xdst->u.rt6);

	atomic_inc(&dev_net(dev)->ipv6.rt6_stats->fib_rt_uncache);



	return 0;

}