[PATCH net-next 1/6] ipv6: prepare RCU lookups for idev->addr_list
From: Eric Dumazet <edumazet@google.com>
Date: 2017-10-08 02:30:39
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
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> --- net/ipv6/addrconf.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 9854d93e45bb5ca919d55e6b875f7dc392a5dae5..d1ff0955b709eaa6b5d94bd8d740334eb1eed6d7 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c@@ -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);
--
2.14.2.920.gcf0c67979c-goog