Subject: Re: [patch net-next-2.6] bonding: remove skb_share_check in handle_frame

From: Nicolas de Pesloüan<[email-masked]>
Date: Wed, 02 Mar 2011 21:47:50 +0100

Le 02/03/2011 11:03, Jiri Pirko a écrit :
> Tue, Mar 01, 2011 at 09:38:43PM CET, [email-masked] wrote:
>> On Tue, Mar 01, 2011 at 10:29:07AM +0100, Jiri Pirko wrote:
>>> Unapplicable, sorry (wrong branch :(). Here's corrected patch:
>>>
>>> Subject: [PATCH net-next-2.6 v2] bonding: remove skb_share_check in handle_frame
>>>
>>> No need to do share check here.
>>>
>>> Signed-off-by: Jiri Pirko<[email-masked]>
>>> ---
>>>   drivers/net/bonding/bond_main.c |    3 ---
>>>   1 files changed, 0 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>>> index 584f97b..367ea60 100644
>>> --- a/drivers/net/bonding/bond_main.c
>>> +++ b/drivers/net/bonding/bond_main.c
>>> @@ -1498,9 +1498,6 @@ static struct sk_buff *bond_handle_frame(struct sk_buff *skb)
>>>   	struct net_device *slave_dev;
>>>   	struct net_device *bond_dev;
>>>
>>> -	skb = skb_share_check(skb, GFP_ATOMIC);
>>> -	if (unlikely(!skb))
>>> -		return NULL;
>>>   	slave_dev = skb->dev;
>>>   	bond_dev = ACCESS_ONCE(slave_dev->master);
>>>   	if (unlikely(!bond_dev))
>>> --
>>> 1.7.3.4
>>>
>>
>> Why did you decide to get rid of it here rather than the 3 places in the
>> bonding driver where it is currently needed?  I think this can cover
>> those cases since bond_handle_frame will be called after the ptype_all
>> handlers before any of the ptype handlers.
>
> I have already a patch prepared which converts bond ptype handlers into
> being called from bond_handle_frame. You are propably right that this
> should probably stay here.

Hi Jiri,

Do you plan to call the bonding ARP handler from inside bond_handle_frame()?

A few days ago (http://marc.info/?l=linux-netdev&m=129883949022340&w=2), I noticed that it is not 
possible to call the bonding ARP handler from inside the bonding rx_handler, because some frame 
processing may be required after the bonding rx_handler call, to put the frame in a suitable state 
for the bonding ARP handler.

This is at least true with the following setup, eth0 -> bond0 -> bond0.100, where the ARP frames are 
VLAN tagged at the time the bonding rx_handler process them.

	Nicolas.