diff mbox series

[5.10,08/29] mptcp: skip to next candidate if subflow has unacked data

Message ID 20210222121021.519452639@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman Feb. 22, 2021, 12:13 p.m. UTC 
From: Florian Westphal <fw@strlen.de>

[ Upstream commit 860975c6f80adae9d2c7654bde04a99dd28bc94f ]

In case a subflow path is blocked, MPTCP-level retransmit may not take
place anymore because such subflow is likely to have unacked data left
in its write queue.

Ignore subflows that have experienced loss and test next candidate.

Fixes: 3b1d6210a95773691 ("mptcp: implement and use MPTCP-level retransmission")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mptcp/protocol.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 967ce9ccfc0da..f56b2e331bb6b 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1648,8 +1648,11 @@  static struct sock *mptcp_subflow_get_retrans(const struct mptcp_sock *msk)
 			continue;
 
 		/* still data outstanding at TCP level?  Don't retransmit. */
-		if (!tcp_write_queue_empty(ssk))
+		if (!tcp_write_queue_empty(ssk)) {
+			if (inet_csk(ssk)->icsk_ca_state >= TCP_CA_Loss)
+				continue;
 			return NULL;
+		}
 
 		if (subflow->backup) {
 			if (!backup)