diff options
| -rw-r--r-- | net/ipv6/ip6_fib.c | 38 |
1 files changed, 29 insertions, 9 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index d11a5578e4f8..9dcc3924a975 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; @@ -1270,13 +1275,17 @@ 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 @@ -1531,6 +1540,12 @@ 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)); @@ -1685,10 +1700,15 @@ 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); } |