Re: [PATCH RESEND net-next] ipv6: mcast: Add ip6_mc_find_idev() helper

[Yue Haibing]

On 2025/8/21 17:42, Paolo Abeni wrote:
> On 8/18/25 12:10 PM, Yue Haibing wrote:
>> @@ -302,32 +310,18 @@ int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
>>  }
>>  EXPORT_SYMBOL(ipv6_sock_mc_drop);
>>  
>> -static struct inet6_dev *ip6_mc_find_dev(struct net *net,
>> -					 const struct in6_addr *group,
>> -					 int ifindex)
>> +static struct inet6_dev *ip6_mc_find_idev(struct net *net,
>> +					  const struct in6_addr *group,
>> +					  int ifindex)
>>  {
>> -	struct net_device *dev = NULL;
>> -	struct inet6_dev *idev;
>> -
>> -	if (ifindex == 0) {
>> -		struct rt6_info *rt;
>> +	struct inet6_dev *idev = NULL;
>> +	struct net_device *dev;
>>  
>> -		rcu_read_lock();
>> -		rt = rt6_lookup(net, group, NULL, 0, NULL, 0);
>> -		if (rt) {
>> -			dev = dst_dev(&rt->dst);
>> -			dev_hold(dev);
>> -			ip6_rt_put(rt);
>> -		}
>> -		rcu_read_unlock();
>> -	} else {
>> -		dev = dev_get_by_index(net, ifindex);
>> +	dev = ip6_mc_find_dev(net, group, ifindex);
>> +	if (dev) {
>> +		idev = in6_dev_get(dev);
>> +		dev_put(dev);
>>  	}
>> -	if (!dev)
>> -		return NULL;
>> -
>> -	idev = in6_dev_get(dev);
>> -	dev_put(dev);
> 
> Not so minor nit: if you omit the last chunk (from 'if (dev) {' onwards,
> unneeded), the patch will be much more obvious and smaller. Also you
> could clarify a bit the commit message.

Thanks, it is indeed more clear, will do this in v2

> You can retain Dawid's ack when posting the next version
> 
> /P
> 
>