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Date: Thu, 24 Mar 2022 18:35:40 +0100
From: Florian Westphal <fw@strlen.de>
To: Paolo Abeni <pabeni@redhat.com>
Cc: Florian Westphal <fw@strlen.de>, mptcp@lists.linux.dev
Subject: Re: [PATCH mptcp-next 4/4] mptcp: let mptcp listen dump show listen
 backlog size
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Paolo Abeni <pabeni@redhat.com> wrote:
> > -	r->idiag_rqueue = sk_rmem_alloc_get(sk);
> > -	r->idiag_wqueue = sk_wmem_alloc_get(sk);
> > +	if (inet_sk_state_load(sk) == TCP_LISTEN) {
> > +		r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog);
> > +		r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog);
> 
> What about accessing msk->first->sk*ack_backlog instead ? Are there any
> possible subtle races? Otherwise sk_ack_backlog will always be 0,
> right?

Yes, msk->first would be better here, will drop this patch
and merge the msk->first bit into preceeding one.