From mboxrd@z Thu Jan  1 00:00:00 1970
From: Florian Westphal <fw@strlen.de>
Subject: Re: [PATCH v2 net-next] net: core: decouple ifalias get/set from
 rtnl lock
Date: Mon, 2 Oct 2017 23:47:35 +0200
Message-ID: <20171002214735.GA1813@breakpoint.cc>
References: <20171002212942.14521-1-fw@strlen.de>
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To: Florian Westphal <fw@strlen.de>
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Florian Westphal <fw@strlen.de> wrote:
> +	mutex_lock(&ifalias_mutex);
> +
> +	old = rcu_dereference_protected(dev->ifalias,
> +					mutex_is_locked(&ifalias_mutex));
> +	if (len) {
> +		memcpy(new_alias->ifalias, alias, len);
> +		new_alias->ifalias[len] = 0;
> +	}

This can be done outside of the lock, so this can be
> +
> +	rcu_assign_pointer(dev->ifalias, new_alias);

rcu_swap_protected().

I'll send a v3.