zhenggy b3507f2bef tcp: fix tp->undo_retrans accounting in tcp_sacktag_one()
commit 4f884f3962767877d7aabbc1ec124d2c307a4257 upstream.

Commit 10d3be569243 ("tcp-tso: do not split TSO packets at retransmit
time") may directly retrans a multiple segments TSO/GSO packet without
split, Since this commit, we can no longer assume that a retransmitted
packet is a single segment.

This patch fixes the tp->undo_retrans accounting in tcp_sacktag_one()
that use the actual segments(pcount) of the retransmitted packet.

Before that commit (10d3be569243), the assumption underlying the
tp->undo_retrans-- seems correct.

Fixes: 10d3be569243 ("tcp-tso: do not split TSO packets at retransmit time")
Signed-off-by: zhenggy <zhenggy@chinatelecom.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22 11:43:09 +02:00
..
2018-04-13 19:48:32 +02:00
2021-09-03 09:44:40 +02:00
2016-09-21 00:23:01 -04:00
2019-04-17 08:36:45 +02:00
2017-05-14 14:00:21 +02:00
2016-09-01 14:09:01 -07:00