Re: [PATCH nf-next v5] netfilter: ipvs: Fix reuse connection if RS weight is 0
From: Simon Horman <horms@verge.net.au>
Date: 2021-11-03 09:55:28
Also in:
lkml, lvs-devel, netdev, netfilter-devel
On Mon, Nov 01, 2021 at 10:04:16AM +0800, yangxingwu wrote:
We are changing expire_nodest_conn to work even for reused connections when
conn_reuse_mode=0, just as what was done with commit dc7b3eb900aa ("ipvs:
Fix reuse connection if real server is dead").
For controlled and persistent connections, the new connection will get the
needed real server depending on the rules in ip_vs_check_template().
Fixes: d752c3645717 ("ipvs: allow rescheduling of new connections when port reuse is detected")
Co-developed-by: Chuanqi Liu <redacted>
Signed-off-by: Chuanqi Liu <redacted>
Signed-off-by: yangxingwu <redacted>Thanks, and sorry but I have a few nits.
quoted hunk ↗ jump to hunk
--- Documentation/networking/ipvs-sysctl.rst | 3 +-- net/netfilter/ipvs/ip_vs_core.c | 8 ++++---- 2 files changed, 5 insertions(+), 6 deletions(-)diff --git a/Documentation/networking/ipvs-sysctl.rst b/Documentation/networking/ipvs-sysctl.rst index 2afccc63856e..1cfbf1add2fc 100644 --- a/Documentation/networking/ipvs-sysctl.rst +++ b/Documentation/networking/ipvs-sysctl.rst@@ -37,8 +37,7 @@ conn_reuse_mode - INTEGER 0: disable any special handling on port reuse. The new connection will be delivered to the same real server that was - servicing the previous connection. This will effectively - disable expire_nodest_conn. + servicing the previous connection.
nit: s/servicing/service/
quoted hunk ↗ jump to hunk
bit 1: enable rescheduling of new connections when it is safe. That is, whenever expire_nodest_conn and for TCP sockets, whendiff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c index 128690c512df..f9d65d2c8da8 100644 --- a/net/netfilter/ipvs/ip_vs_core.c +++ b/net/netfilter/ipvs/ip_vs_core.c@@ -1964,7 +1964,6 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int struct ip_vs_proto_data *pd; struct ip_vs_conn *cp; int ret, pkts; - int conn_reuse_mode; struct sock *sk; /* Already marked as IPVS request or reply? */@@ -2041,15 +2040,16 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int cp = INDIRECT_CALL_1(pp->conn_in_get, ip_vs_conn_in_get_proto, ipvs, af, skb, &iph); - conn_reuse_mode = sysctl_conn_reuse_mode(ipvs); - if (conn_reuse_mode && !iph.fragoffs && is_new_conn(skb, &iph) && cp) { + if (!iph.fragoffs && is_new_conn(skb, &iph) && cp) { bool old_ct = false, resched = false; + int conn_reuse_mode = sysctl_conn_reuse_mode(ipvs);
We should probably try to move towards reverse xmas tree, which is preferred for Linux network code these days. So could you move the conn_reuse_mode line above the bool line?
if (unlikely(sysctl_expire_nodest_conn(ipvs)) && cp->dest &&
unlikely(!atomic_read(&cp->dest->weight))) {
resched = true;
old_ct = ip_vs_conn_uses_old_conntrack(cp, skb);
- } else if (is_new_conn_expected(cp, conn_reuse_mode)) {
+ } else if (conn_reuse_mode &&
+ is_new_conn_expected(cp, conn_reuse_mode)) {
old_ct = ip_vs_conn_uses_old_conntrack(cp, skb);
if (!atomic_read(&cp->n_control)) {
resched = true;
--
2.30.2