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: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2017-10-07 19:30:23 -07:00 committed by David S. Miller
parent a42317785c
commit 8ef802aa8e
1 changed files with 6 additions and 15 deletions

View File

@ -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 @@ restart:
*/
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 @@ restart:
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 @@ restart:
}
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);