Re: [mptcp-next 0/2] Fix mptcp connection hangs after link failover

[Mat Martineau <mathew.j.martineau@linux.intel.com>]

On Wed, 8 Sep 2021, Florian Westphal wrote:

> Florian Westphal <fw@strlen.de> wrote:
>> Mat Martineau <mathew.j.martineau@linux.intel.com> wrote:
>>> On Mon, 6 Sep 2021, Florian Westphal wrote:
>>>
>>>> First patch is preparation work: tx_pending_data counter is unreliable.
>>>> Second patch fixes premature stop of the retransmit timer.
>>>>
>>>> Florian Westphal (2):
>>>>  mptcp: remove tx_pending_data
>>>>  mptcp: re-set push-pending bit on retransmit failure
>>>>
>>>> net/mptcp/protocol.c | 32 +++++++++++++++++++++++++-------
>>>> net/mptcp/protocol.h |  1 -
>>>> 2 files changed, 25 insertions(+), 8 deletions(-)
>>>>
>>>> --
>>>> 2.32.0
>>>
>>> The code changes look ok, and I don't see any copyfd_io_poll errors. But I
>>> do get consistent failures in the same group of self tests related to stale
>>> links and recovery:
>>>
>>> 15 multiple flows, signal, link failure syn[ ok ] - synack[ ok ] - ack[ ok ]
>>>                                         add[ ok ] - echo  [ ok ]
>>>                                         stale             [fail] got 0
>>> stale[s] 0 recover[s],   expected stale in range [1..5],  stale-recover
>>> delta 1
>>
>> I'm on export, 9c7d1b9a14eba479466423d64f99c8a4e29b66f4, with these two
>> patches and I don't see this error.
>>
>> Running mptcp_join -l in a loop now, no luck so far.
>
> Gave up, its not triggering for me.
>
> Any hints on reproducing this?
>
> Does it pass for you without my changes?
>
> I don't see how they would cause this; if anything this patch makes
> the stale detection reliable because the retrans timer is not stopped
> too early anymore and it makes sure that mptcp_subflow_get_retrans() is
> called once for each retrans timer call.
>

Hi Florian -

My apologies for wasting your time on this, it was 100% user error on my 
side. With everything set up right on my end, the tests are passing.

So, the changes look good:

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>

--
Mat Martineau
Intel