thanks Julian

I will do that

On Sat, Oct 30, 2021 at 3:25 AM Julian Anastasov [off-list ref] wrote:

        Hello,

On Fri, 29 Oct 2021, yangxingwu wrote:

quoted

Since commit dc7b3eb900aa ("ipvs: Fix reuse connection if real server is
dead"), new connections to dead servers are redistributed immediately to
new servers.

Then commit d752c3645717 ("ipvs: allow rescheduling of new connections when
port reuse is detected") disable expire_nodest_conn if conn_reuse_mode is
0. And new connection may be distributed to a real server with weight 0.

        Can you better explain in commit message that we are changing
expire_nodest_conn to work even for reused connections when
conn_reuse_mode=0 but without affecting the controlled/persistent
connections during the grace period while server is with weight=0.

        Even if you target -next trees adding commit d752c3645717
as Fixes line would be a good idea. Make sure the tree is specified
after the v3 tag.

quoted

Co-developed-by: Chuanqi Liu <redacted>
Signed-off-by: Chuanqi Liu <redacted>
Signed-off-by: yangxingwu <redacted>
---
 Documentation/networking/ipvs-sysctl.rst | 3 +--
 net/netfilter/ipvs/ip_vs_core.c          | 7 ++++---
 2 files changed, 5 insertions(+), 5 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.

      bit 1: enable rescheduling of new connections when it is safe.
      That is, whenever expire_nodest_conn and for TCP sockets, when

diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index 128690c512df..374f4b0b7080 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c

@@ -2042,14 +2042,15 @@ ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int
                           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) {

        It is even better to move the !cp->control check above:

        if (!iph.fragoffs && is_new_conn(skb, &iph) && cp && !cp->control) {

        Then is not needed in is_new_conn_expected() anymore.

quoted

              bool old_ct = false, resched = false;

        And now you can move conn_reuse_mode here:

                int conn_reuse_mode = sysctl_conn_reuse_mode(ipvs);

quoted

              if (unlikely(sysctl_expire_nodest_conn(ipvs)) && cp->dest &&
-                 unlikely(!atomic_read(&cp->dest->weight))) {
+                 unlikely(!atomic_read(&cp->dest->weight)) && !cp->control) {
                      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

Regards

--
Julian Anastasov [off-list ref]