Re: [PATCH v2 net-next 2/3] ipvlan: Common code from v6/v4 validator_event

[Dmitry Skorodumov <skorodumov.dmitry@huawei.com>]

On 1/26/2026 9:01 PM, Kuniyuki Iwashima wrote:
> On Fri, Jan 23, 2026 at 9:04 AM Dmitry Skorodumov <dskr99@gmail.com> wrote:

>> +static int ipvlan_addr_validator_event_cb(struct notifier_block *nblock,
>> +                                         unsigned long event, void *ptr)
>> +{
>> +       struct in6_validator_info *i6vi;
>> +       struct net_device *dev;
>> +
>> +       if (nblock == &ipvlan_addr4_vtor_notifier_block) {
> 
> If you check this against the v6 one instead, the if block
> and the i6vi definition can be guarded with
> #if IS_ENABLED(CONFIG_IPV6)

Hm... Few months ago, I had a conversation here that convinced me: avoid 
#ifdef whenever possible. They overburden code and reduce readability.

It even might be a good idea to replace wherever possible preprocessor 
checks with runtime checks. Use
if (IS_ENABLED(CONFIG_IPV6)) { ... }

instead of #if IS_ENABLED(CONFIG_IPV6) ... #endif

--

I'm ok with both approaches (though i tend to like runtime checks) - but 
unsure what is a common practice in bpf-net

Dmitry