Re: [net-next] bonding: don't allow the master to become its slave

[Jiri Pirko <jpirko@redhat.com>]

Thu, Aug 09, 2012 at 09:03:23PM CEST, bhutchings@solarflare.com wrote:
>On Thu, 2012-08-09 at 15:30 -0300, Flavio Leitner wrote:
>> It doesn't make any sense to allow the master to become
>> its slave. That creates a loop of events causing a crash.
>
>What if there are other intermediate devices, e.g. the slave is a VLAN
>sub-device of the bond?  And doesn't team also have this problem?

Yes, it does.

>
>I think a more general check for such loops might be required.

I agree.
>
>Ben.
>
>> Reported-by: Leonardo Chiquitto <lchiquitto@suse.com>
>> Signed-off-by: Flavio Leitner <fbl@redhat.com>
>> ---
>>  drivers/net/bonding/bond_main.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>> 
>> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>> index 6fae5f3..5407b44 100644
>> --- a/drivers/net/bonding/bond_main.c
>> +++ b/drivers/net/bonding/bond_main.c
>> @@ -1505,6 +1505,11 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
>>  	int link_reporting;
>>  	int res = 0;
>>  
>> +	if (bond_dev == slave_dev) {
>> +		pr_err("%s: Error: cannot enslave itself.\n", bond_dev->name);
>> +		return -EINVAL;
>> +	}
>> +
>>  	if (!bond->params.use_carrier && slave_dev->ethtool_ops == NULL &&
>>  		slave_ops->ndo_do_ioctl == NULL) {
>>  		pr_warning("%s: Warning: no link monitoring support for %s\n",
>
>-- 
>Ben Hutchings, Staff Engineer, Solarflare
>Not speaking for my employer; that's the marketing department's job.
>They asked us to note that Solarflare product names are trademarked.
>