From mboxrd@z Thu Jan  1 00:00:00 1970
From: ebiederm@xmission.com (Eric W. Biederman)
Subject: Re: [PATCH net-next 6/6] tcp_metrics: Use a single hash table for all network namespaces.
Date: Mon, 09 Mar 2015 14:35:29 -0500
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Cc: David Miller <davem@davemloft.net>, edumazet@google.com,
	netdev@vger.kernel.org, stephen@networkplumber.org,
	nicolas.dichtel@6wind.com, roopa@cumulusnetworks.com,
	hannes@stressinduktion.org, ddutt@cumulusnetworks.com,
	vipin@cumulusnetworks.com, shmulik.ladkani@gmail.com,
	dsahern@gmail.com
To: Eric Dumazet <eric.dumazet@gmail.com>
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	(Eric Dumazet's message of "Mon, 09 Mar 2015 11:47:08 -0700")
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Eric Dumazet <eric.dumazet@gmail.com> writes:

> On Mon, 2015-03-09 at 13:31 -0500, Eric W. Biederman wrote:
>
>> @@ -1167,17 +1173,22 @@ static void __net_exit tcp_net_metrics_exit(struct net *net)
>>  {
>>  	unsigned int i;
>>  
>> -	for (i = 0; i < (1U << net->ipv4.tcp_metrics_hash_log) ; i++) {
>> +	if (net != &init_net) {
>> +		tcp_metrics_flush_all(net);
>> +		return;
>> +	}
>
> Note this _very_ unlikely (read: not possible) that
> tcp_net_metrics_exit() will ever be called on init_net
>
> So I would remove all this code.

If the line:
	ret = genl_register_family_with_ops(&tcp_metrics_nl_family,
					    tcp_metrics_nl_ops);

fails then this code will be called with net == &init_net.

Eric