From d8a6e65f8b6b6b0142ebab578472906d89d63657 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 30 Nov 2011 01:02:41 +0000 Subject: tcp: inherit listener congestion control for passive cnx Rick Jones reported that TCP_CONGESTION sockopt performed on a listener was ignored for its children sockets : right after accept() the congestion control for new socket is the system default one. This seems an oversight of the initial design (quoted from Stephen) Based on prior investigation and patch from Rick. Reported-by: Rick Jones Signed-off-by: Eric Dumazet CC: Stephen Hemminger CC: Yuchung Cheng Tested-by: Rick Jones Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 3 +++ net/ipv4/tcp_ipv4.c | 1 + net/ipv4/tcp_minisocks.c | 4 +++- 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index b8867061fce4..cb2b1c6a2ce1 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -175,6 +175,9 @@ tcp_congestion_control - STRING connections. The algorithm "reno" is always available, but additional choices may be available based on kernel configuration. Default is set as part of kernel configuration. + For passive connections, the listener congestion control choice + is inherited. + [see setsockopt(listenfd, SOL_TCP, TCP_CONGESTION, "name" ...) ] tcp_cookie_size - INTEGER Default size of TCP Cookie Transactions (TCPCT) option, that may be diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index a9db4b1a2215..c4b8b09db9f5 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1511,6 +1511,7 @@ exit: return NULL; put_and_exit: tcp_clear_xmit_timers(newsk); + tcp_cleanup_congestion_control(newsk); bh_unlock_sock(newsk); sock_put(newsk); goto exit; diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 945efffdd929..9dc146e5ed65 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -495,7 +495,9 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req, newtp->frto_counter = 0; newtp->frto_highmark = 0; - newicsk->icsk_ca_ops = &tcp_init_congestion_ops; + if (newicsk->icsk_ca_ops != &tcp_init_congestion_ops && + !try_module_get(newicsk->icsk_ca_ops->owner)) + newicsk->icsk_ca_ops = &tcp_init_congestion_ops; tcp_set_ca_state(newsk, TCP_CA_Open); tcp_init_xmit_timers(newsk); -- cgit v1.2.3