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 --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)