From c948bb5c2cc4d63f9d76fc02baf5a8331e3cd27f Mon Sep 17 00:00:00 2001 From: Sowmini Varadhan Date: Wed, 18 May 2016 10:06:24 -0700 Subject: [PATCH] RDS: TCP: Avoid rds connection churn from rogue SYNs When a rogue SYN is received after the connection arbitration algorithm has converged, the incoming SYN should not needlessly quiesce the transmit path, and it should not result in needless TCP connection resets due to re-execution of the connection arbitration logic. Signed-off-by: Sowmini Varadhan Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller --- net/rds/tcp_listen.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c index 094a8ca..4bf4bef 100644 --- a/net/rds/tcp_listen.c +++ b/net/rds/tcp_listen.c @@ -132,11 +132,13 @@ int rds_tcp_accept_one(struct socket *sock) * so we must quiesce any send threads before resetting * c_transport_data. */ - wait_event(conn->c_waitq, - !test_bit(RDS_IN_XMIT, &conn->c_flags)); - if (ntohl(inet->inet_saddr) < ntohl(inet->inet_daddr)) { + if (ntohl(inet->inet_saddr) < ntohl(inet->inet_daddr) || + !conn->c_outgoing) { goto rst_nsk; - } else if (rs_tcp->t_sock) { + } else { + atomic_set(&conn->c_state, RDS_CONN_CONNECTING); + wait_event(conn->c_waitq, + !test_bit(RDS_IN_XMIT, &conn->c_flags)); rds_tcp_restore_callbacks(rs_tcp->t_sock, rs_tcp); conn->c_outgoing = 0; } -- 2.7.4