[MPTCP] Re: [RFC PATCH 11/12] mptcp: allow picking different xmit subflows

[Florian Westphal <fw at strlen.de>]

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Paolo Abeni <pabeni(a)redhat.com> wrote:
> > Checking 'fallback' made no sense to me.  Why do we need to check for this?
> 
> In teory we should not have additional subflows in the fallback status,
> but we can have an MPJ handskake and fallback racing togethar, so we
> end-up with msk in fallback status and one or more fully established
> subflows. If/when that happen we must avoid picking mpj subflows. 

That sounds bad.  I'd suggest to make sure that we only use
msk->first if msk is marked fallback.

> Perhaps is just easier/clearer add an explict (unlikely???) case
> in mptcp_subflow_get_send() and mptcp_subflow_get_retrans()

Agree, its easier to understand, at least.

> > > > Hmm, should this be a separate bug fix (prevent non-fully-established-join)?
> > > 
> > > I think the bug is only apparent after we have non backup subflows
> > > and/or remove addr support ?!?
> > 
> > What about other mptcp stack peer?  Couldn't they create a non-backup flow?
> > 
> > [ I don't mind if you don't want a separate patch for this, it just
> > looked like a small fix to me that could be applied already ]
> 
> yep, we can have non backup subflows with mptcp.org peers. I still
> would opt for a single patch ;)

Ok, fair enough, I thought you could split that from the series and
get it merged already.