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Commit 8ef802aa authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ipv6: prepare RCU lookups for idev->addr_list 



inet6_ifa_finish_destroy() already uses kfree_rcu() to free
inet6_ifaddr structs.

We need to use proper list additions/deletions in order
to allow readers to use RCU instead of idev->lock rwlock.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a4231778

net/ipv6/addrconf.c

+6 −15
Original line number Diff line number Diff line
@@ -945,7 +945,7 @@ ipv6_link_dev_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp) 
			break;

	}



	list_add_tail(&ifp->if_list, p);

	list_add_tail_rcu(&ifp->if_list, p);

}



static u32 inet6_addr_hash(const struct in6_addr *addr)
@@ -1204,7 +1204,7 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp) 
	if (ifp->flags & IFA_F_PERMANENT && !(ifp->flags & IFA_F_NOPREFIXROUTE))

		action = check_cleanup_prefix_route(ifp, &expires);



	list_del_init(&ifp->if_list);

	list_del_rcu(&ifp->if_list);

	__in6_ifa_put(ifp);



	write_unlock_bh(&ifp->idev->lock);
@@ -3562,7 +3562,6 @@ static int addrconf_ifdown(struct net_device *dev, int how) 
	struct net *net = dev_net(dev);

	struct inet6_dev *idev;

	struct inet6_ifaddr *ifa, *tmp;

	struct list_head del_list;

	int _keep_addr;

	bool keep_addr;

	int state, i;
@@ -3654,7 +3653,6 @@ static int addrconf_ifdown(struct net_device *dev, int how) 
	 */

	keep_addr = (!how && _keep_addr > 0 && !idev->cnf.disable_ipv6);



	INIT_LIST_HEAD(&del_list);

	list_for_each_entry_safe(ifa, tmp, &idev->addr_list, if_list) {

		struct rt6_info *rt = NULL;

		bool keep;
@@ -3663,8 +3661,6 @@ static int addrconf_ifdown(struct net_device *dev, int how) 


		keep = keep_addr && (ifa->flags & IFA_F_PERMANENT) &&

			!addr_is_local(&ifa->addr);

		if (!keep)

			list_move(&ifa->if_list, &del_list);



		write_unlock_bh(&idev->lock);

		spin_lock_bh(&ifa->lock);
@@ -3698,19 +3694,14 @@ static int addrconf_ifdown(struct net_device *dev, int how) 
		}



		write_lock_bh(&idev->lock);

		if (!keep) {

			list_del_rcu(&ifa->if_list);

			in6_ifa_put(ifa);

		}

	}



	write_unlock_bh(&idev->lock);



	/* now clean up addresses to be removed */

	while (!list_empty(&del_list)) {

		ifa = list_first_entry(&del_list,

				       struct inet6_ifaddr, if_list);

		list_del(&ifa->if_list);



		in6_ifa_put(ifa);

	}



	/* Step 5: Discard anycast and multicast list */

	if (how) {

		ipv6_ac_destroy_dev(idev);