Re: [PATCH mptcp-next v5 01/12] mptcp: do not drop partial packets

[Matthieu Baerts <matttbe@kernel.org>]

Hi Paolo, Shardul,

On 10/05/2026 23:03, Paolo Abeni wrote:
> From: Shardul Bankar <shardul.b@mpiricsoftware.com>
> 
> When a packet arrives with map_seq < ack_seq < end_seq, the beginning
> of the packet has already been acknowledged but the end contains new
> data.  Currently the entire packet is dropped as "old data," forcing
> the sender to retransmit.
> 
> Instead, skip the already-acked bytes by adjusting the skb offset and
> enqueue only the new portion.  Update bytes_received and ack_seq to
> reflect the new data consumed.
> 
> A previous attempt at this fix (commit 1d2ce718811a ("mptcp: do not
> drop partial packets"), reverted in commit bf39160c4218 ("Revert
> "mptcp: do not drop partial packets"")) also added a zero-window
> check and changed rcv_wnd_sent initialization, which caused test
> regressions.  This version addresses only the partial packet handling
> without modifying receive window accounting.
> 
> Fixes: ab174ad8ef76 ("mptcp: move ooo skbs into msk out of order queue.")
> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/600
> Signed-off-by: Shardul Bankar <shardul.b@mpiricsoftware.com>
> [pabeni@redhat.com: update map]
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
> v2 -> v3:
>   - update map_seq, too
> v2: https://lore.kernel.org/mptcp/20260422143931.43281-1-shardul.b@mpiricsoftware.com/

Thank you for this new version!

I suggest already applying this patch to our tree, so I can send it soon
to netdev.

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.