> -----Original Message-----
> From: Xue, Ying [mailto:ying....@windriver.com]
> Sent: Tuesday, 16 February, 2016 08:42
> To: Jon Maloy; tipc-discussion@lists.sourceforge.net; Parthasarathy
> Bhuvaragan;
> Richard Alpe; huzhiji...@gmail.com
> Cc: ma...@donjonn.com
> Subject: RE: [PATCH net-next 1/1] tipc: eliminate risk of finding
> to-be-deleted
> node instance
>
> @@ -395,21 +396,19 @@ static void tipc_node_delete(struct tipc_node *node) {
> list_del_rcu(&node->list);
> hlist_del_rcu(&node->hash);
>
> It's better to move two lines of code above to tipc_node_kref_release(),
> ensuring we remove the node from the two lists only when node is released.
I beg to disagree. This was one of the points with this change; to remove the
node from the lookup table as early as possible, to reduce the risk that
node_find() finds it after it is marked for deletion. Actually, if I had put a
synchronize_rcu() after those two lines I believe we would have been completely
safe, but I prefer Jason's suggestion, to use kref_put_if_not_zero(). The risk
that
this function will ever return zero (false) should now be minimal. Besides, I
simply
think this is more logical, as I stated in the commit log.
Regards
///jon
>
> Regards,
> Ying
>
> - kfree(node->bc_entry.link);
> - kfree_rcu(node, rcu);
> + tipc_node_put(node);
> + if (del_timer(&node->timer))
> + tipc_node_put(node);
> }
>
> void tipc_node_stop(struct net *net)
> {
> - struct tipc_net *tn = net_generic(net, tipc_net_id);
> + struct tipc_net *tn = tipc_net(net);
> struct tipc_node *node, *t_node;
>
> spin_lock_bh(&tn->node_list_lock);
> - list_for_each_entry_safe(node, t_node, &tn->node_list, list) {
> - if (del_timer(&node->timer))
> - tipc_node_put(node);
> - tipc_node_put(node);
> - }
> + list_for_each_entry_safe(node, t_node, &tn->node_list, list)
> + tipc_node_delete(node);
> spin_unlock_bh(&tn->node_list_lock);
> }
>
> --
> 1.9.1
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