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Date: Wed, 10 Nov 2021 12:49:20 +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 3/3] mptcp: add SIOCINQ, OUTQ and OUTQNSD
 ioctls
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Paolo Abeni <pabeni@redhat.com> wrote:
> > Bah.  You are right. TBH I do not understand READ|WRITE_ONCE usage in
> > mptcp anymore.  Maybe its correct, who knows.
> > 
> > The different locking schemes are not easy to follow for me.
> 
> Indeed I agreed!
> 
> I *think* (mostly guess) some _ONCE() annotation are now obsoleted/made
> unnecessary by the several re-factors.
> 
> For sure we need to document clarely the locking schema (where? how?
> would comments on the protectect fields suffice?) and possibly/likely
> review the current annotations.

I think adding comments in the mptcp_sock struct would be a great start.

> > > BTW this always reports '1' on fallback sockets after shutdown, as
> > > after shutdown write_seq is incremented by 1, but snd_una/snd_nxt are
> > > not incremented when receiving the TCP fin. I guess the fix not
> > > strictly related to this patch.
> > 
> > That should be ok, we should return nonzero inq hint when next read()
> > would indicate EOF.
> 
> This is for the outq ?!? I think it should be 0 after all outstanding
> data is acked ?!?

Oh, I misread it as inq.