From: zhenggy <zhenggy@chinatelecom.cn>
To: ncardwell@google.com, netdev@vger.kernel.org
Cc: edumazet@google.com, davem@davemloft.net,
yoshfuji@linux-ipv6.org, dsahern@kernel.org, kuba@kernel.org,
ycheng@google.com, qitiepeng@chinatelecom.cn,
wujianguo@chinatelecom.cn, liyonglong@chinatelecom.cn,
luchang1@chinatelecom.cn, zhenggy <zhenggy@chinatelecom.cn>
Subject: [PATCH v4] tcp: fix tp->undo_retrans accounting in tcp_sacktag_one()
Date: Tue, 14 Sep 2021 09:51:15 +0800 [thread overview]
Message-ID: <1631584275-3075-1-git-send-email-zhenggy@chinatelecom.cn> (raw)
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>
---
net/ipv4/tcp_input.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 3f7bd7a..141e85e 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1346,7 +1346,7 @@ static u8 tcp_sacktag_one(struct sock *sk,
if (dup_sack && (sacked & TCPCB_RETRANS)) {
if (tp->undo_marker && tp->undo_retrans > 0 &&
after(end_seq, tp->undo_marker))
- tp->undo_retrans--;
+ tp->undo_retrans = max_t(int, 0, tp->undo_retrans - pcount);
if ((sacked & TCPCB_SACKED_ACKED) &&
before(start_seq, state->reord))
state->reord = start_seq;
--
1.8.3.1
next reply other threads:[~2021-09-14 1:51 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-14 1:51 zhenggy [this message]
2021-09-14 13:30 ` [PATCH v4] tcp: fix tp->undo_retrans accounting in tcp_sacktag_one() patchwork-bot+netdevbpf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1631584275-3075-1-git-send-email-zhenggy@chinatelecom.cn \
--to=zhenggy@chinatelecom.cn \
--cc=davem@davemloft.net \
--cc=dsahern@kernel.org \
--cc=edumazet@google.com \
--cc=kuba@kernel.org \
--cc=liyonglong@chinatelecom.cn \
--cc=luchang1@chinatelecom.cn \
--cc=ncardwell@google.com \
--cc=netdev@vger.kernel.org \
--cc=qitiepeng@chinatelecom.cn \
--cc=wujianguo@chinatelecom.cn \
--cc=ycheng@google.com \
--cc=yoshfuji@linux-ipv6.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).