diff options
Diffstat (limited to 'net/ipv6/ip6_fib.c')
| -rw-r--r-- | net/ipv6/ip6_fib.c | 83 |
1 files changed, 57 insertions, 26 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index f5285f4e1d08..217683d40f12 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -640,6 +640,11 @@ static struct fib6_node *fib6_add_1(struct net *net, if (!(fn->fn_flags & RTN_RTINFO)) { RCU_INIT_POINTER(fn->leaf, NULL); rt6_release(leaf); + /* remove null_entry in the root node */ + } else if (fn->fn_flags & RTN_TL_ROOT && + rcu_access_pointer(fn->leaf) == + net->ipv6.ip6_null_entry) { + RCU_INIT_POINTER(fn->leaf, NULL); } return fn; @@ -1221,8 +1226,14 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt, } if (!rcu_access_pointer(fn->leaf)) { - atomic_inc(&rt->rt6i_ref); - rcu_assign_pointer(fn->leaf, rt); + if (fn->fn_flags & RTN_TL_ROOT) { + /* put back null_entry for root node */ + rcu_assign_pointer(fn->leaf, + info->nl_net->ipv6.ip6_null_entry); + } else { + atomic_inc(&rt->rt6i_ref); + rcu_assign_pointer(fn->leaf, rt); + } } fn = sn; } @@ -1241,23 +1252,28 @@ out: * If fib6_add_1 has cleared the old leaf pointer in the * super-tree leaf node we have to find a new one for it. */ - struct rt6_info *pn_leaf = rcu_dereference_protected(pn->leaf, - lockdep_is_held(&table->tb6_lock)); - if (pn != fn && pn_leaf == rt) { - pn_leaf = NULL; - RCU_INIT_POINTER(pn->leaf, NULL); - atomic_dec(&rt->rt6i_ref); - } - if (pn != fn && !pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { - pn_leaf = fib6_find_prefix(info->nl_net, table, pn); -#if RT6_DEBUG >= 2 - if (!pn_leaf) { - WARN_ON(!pn_leaf); - pn_leaf = info->nl_net->ipv6.ip6_null_entry; + if (pn != fn) { + struct rt6_info *pn_leaf = + rcu_dereference_protected(pn->leaf, + lockdep_is_held(&table->tb6_lock)); + if (pn_leaf == rt) { + pn_leaf = NULL; + RCU_INIT_POINTER(pn->leaf, NULL); + atomic_dec(&rt->rt6i_ref); } + if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) { + pn_leaf = fib6_find_prefix(info->nl_net, table, + pn); +#if RT6_DEBUG >= 2 + if (!pn_leaf) { + WARN_ON(!pn_leaf); + pn_leaf = + info->nl_net->ipv6.ip6_null_entry; + } #endif - atomic_inc(&pn_leaf->rt6i_ref); - rcu_assign_pointer(pn->leaf, pn_leaf); + atomic_inc(&pn_leaf->rt6i_ref); + rcu_assign_pointer(pn->leaf, pn_leaf); + } } #endif goto failure; @@ -1265,13 +1281,17 @@ out: return err; failure: - /* fn->leaf could be NULL if fn is an intermediate node and we - * failed to add the new route to it in both subtree creation - * failure and fib6_add_rt2node() failure case. - * In both cases, fib6_repair_tree() should be called to fix - * fn->leaf. + /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if: + * 1. fn is an intermediate node and we failed to add the new + * route to it in both subtree creation failure and fib6_add_rt2node() + * failure case. + * 2. fn is the root node in the table and we fail to add the first + * default route to it. */ - if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT))) + if (fn && + (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) || + (fn->fn_flags & RTN_TL_ROOT && + !rcu_access_pointer(fn->leaf)))) fib6_repair_tree(info->nl_net, table, fn); /* Always release dst as dst->__refcnt is guaranteed * to be taken before entering this function @@ -1526,6 +1546,12 @@ static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_walker *w; int iter = 0; + /* Set fn->leaf to null_entry for root node. */ + if (fn->fn_flags & RTN_TL_ROOT) { + rcu_assign_pointer(fn->leaf, net->ipv6.ip6_null_entry); + return fn; + } + for (;;) { struct fib6_node *fn_r = rcu_dereference_protected(fn->right, lockdep_is_held(&table->tb6_lock)); @@ -1680,10 +1706,15 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, } read_unlock(&net->ipv6.fib6_walker_lock); - /* If it was last route, expunge its radix tree node */ + /* If it was last route, call fib6_repair_tree() to: + * 1. For root node, put back null_entry as how the table was created. + * 2. For other nodes, expunge its radix tree node. + */ if (!rcu_access_pointer(fn->leaf)) { - fn->fn_flags &= ~RTN_RTINFO; - net->ipv6.rt6_stats->fib_route_nodes--; + if (!(fn->fn_flags & RTN_TL_ROOT)) { + fn->fn_flags &= ~RTN_RTINFO; + net->ipv6.rt6_stats->fib_route_nodes--; + } fn = fib6_repair_tree(net, table, fn); } |