From: Matthieu Baerts <matthieu.baerts@tessares.net>
To: Paolo Abeni <pabeni@redhat.com>,
Mat Martineau <mathew.j.martineau@linux.intel.com>
Cc: mptcp@lists.linux.dev
Subject: Re: [PATCH mptcp-net] mptcp: wake-up readers only for in sequence data.
Date: Fri, 4 Jun 2021 21:58:23 +0200 [thread overview]
Message-ID: <e21808b1-36c0-62fe-e9b2-25020573f4c7@tessares.net> (raw)
In-Reply-To: <5009954210af20796d1cf88ca630d19ec12e2132.1622132690.git.pabeni@redhat.com>
Hi Paolo, Mat,
On 27/05/2021 18:27, Paolo Abeni wrote:
> Currently we relay on the subflow->data_avail field,
> which is subject to races:
>
> ssk1
> skb len = 500 DSS(seq=1, len=1000, off=0)
> # data_avail == MPTCP_SUBFLOW_DATA_AVAIL
>
> ssk2
> skb len = 500 DSS(seq = 501, len=1000)
> # data_avail == MPTCP_SUBFLOW_DATA_AVAIL
>
> ssk1
> skb len = 500 DSS(seq = 1, len=1000, off =500)
> # still data_avail == MPTCP_SUBFLOW_DATA_AVAIL,
> # as the skb is covered by a pre-existing map,
> # which was in-sequence at reception time.
>
> Instead we can explicitly check if some has been received in-sequence,
> propagating the info from __mptcp_move_skbs_from_subflow().
>
> Additionally and the 'ONCE' annotation to the 'data_avail' memory
> access, as msk will read it outside the subflow socket lock.
>
> Fixes: 648ef4b88673 ("mptcp: Implement MPTCP receive path")
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Thank you for the patch and the review!
Just applied in our tree:
- 508f97cb7d94: mptcp: wake-up readers only for in sequence data
- Results: 119541ecd3c9..02c88cfc4215
Builds and tests are now in progress:
https://cirrus-ci.com/github/multipath-tcp/mptcp_net-next/export/20210604T195755
https://github.com/multipath-tcp/mptcp_net-next/actions/workflows/build-validation.yml?query=branch:export/20210604T195755
Cheers,
Matt
--
Tessares | Belgium | Hybrid Access Solutions
www.tessares.net
next prev parent reply other threads:[~2021-06-04 19:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-27 16:27 [PATCH mptcp-net] mptcp: wake-up readers only for in sequence data Paolo Abeni
2021-05-28 0:56 ` Mat Martineau
2021-06-04 19:58 ` Matthieu Baerts [this message]
2021-06-05 9:18 ` Matthieu Baerts
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