From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jiri Pirko <jiri@resnulli.us>
Subject: Re: [PATCH net-next v1 5/9] bonding: convert bond_has_this_ip() to
 use upper devices
Date: Tue, 27 Aug 2013 13:25:29 +0200
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Cc: netdev@vger.kernel.org, Jay Vosburgh <fubar@us.ibm.com>,
	Andy Gospodarek <andy@greyhouse.net>
To: Veaceslav Falico <vfalico@redhat.com>
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Tue, Aug 27, 2013 at 01:16:48PM CEST, vfalico@redhat.com wrote:
>On Mon, Aug 26, 2013 at 10:53:38PM +0200, Jiri Pirko wrote:
>>Mon, Aug 26, 2013 at 10:32:38PM CEST, vfalico@redhat.com wrote:
>...snip...
>>>+	rcu_read_lock();
>>>+	netdev_for_each_upper_dev(bond->dev, upper, iter) {
>>>+		if (ip == bond_confirm_addr(upper, 0, ip)) {
>>>+			ret = true;
>>>+			break;
>>>+		}
>>
>>You need the same recursion __vlan_find_dev_deep() is doing. If you do
>>not do that, you will miss anything over the first upper level.
>
>Good point, and it's true for other uses also - bond_arp_send_all(), for
>example, will also miss anything that's higher than the first upper level.
>
>I can't think of a use case scenario when we would need only the first
>upper level - so maybe we should either make netdev_for_each_upper_dev()
>recursive by default (I don't know how it can be done easily, tbh, without
>modifying the existing code), or add something like:
>
>diff --git a/net/core/dev.c b/net/core/dev.c
>index 566e99a..4a4468f 100644
>--- a/net/core/dev.c
>+++ b/net/core/dev.c
>@@ -4387,6 +4387,31 @@ static void __append_search_uppers(struct list_head *search_list,
> 	}
> }
>+struct net_device *netdev_upper_recursive_do_rcu(struct net_device *dev,
>+						 struct net_device *orig_dev,
>+						 bool (*f)(struct net_device *,
>+							   struct net_device *))
>+{
>+	struct netdev_upper *upper;
>+	struct net_device *ret = NULL;
>+
>+	list_for_each_entry_rcu(upper, &dev->upper_dev_list, list) {
>+		if (f(orig_dev, upper->dev)) {
>+			ret = upper->dev;
>+			break;
>+		}
>+
>+		if (!list_empty(&upper->dev->upper_dev_list)) {
>+			ret = netdev_upper_recursive_do_rcu(upper->dev,
>+							    orig_dev, f);
>+			if (ret)
>+				break;
>+		}
>+	}
>+
>+	return ret;
>+}
>+
> static bool __netdev_search_upper_dev(struct net_device *dev,
> 				      struct net_device *upper_dev)
> {
>
>How do you think?

I do not like this. How about to put all levels to upper_dev list and
mark those who are not direct (not level1) ? Then we can use single list
for all purposes.