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* [PATCH v2] ipvs: Fix reuse connection if RS weight is 0
@ 2021-10-29  3:26 yangxingwu
  2021-10-29 19:25 ` Julian Anastasov
  0 siblings, 1 reply; 3+ messages in thread
From: yangxingwu @ 2021-10-29  3:26 UTC (permalink / raw)
  To: horms
  Cc: ja, pablo, kadlec, fw, davem, kuba, netdev, lvs-devel,
	netfilter-devel, coreteam, linux-kernel, linux-doc, corbet,
	xingwu.yang, legend050709

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.

Co-developed-by: Chuanqi Liu <legend050709@qq.com>
Signed-off-by: Chuanqi Liu <legend050709@qq.com>
Signed-off-by: yangxingwu <xingwu.yang@gmail.com>
---
 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) {
 		bool old_ct = false, resched = false;
 
 		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


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH v2] ipvs: Fix reuse connection if RS weight is 0
  2021-10-29  3:26 [PATCH v2] ipvs: Fix reuse connection if RS weight is 0 yangxingwu
@ 2021-10-29 19:25 ` Julian Anastasov
  2021-10-30  2:42   ` yangxingwu
  0 siblings, 1 reply; 3+ messages in thread
From: Julian Anastasov @ 2021-10-29 19:25 UTC (permalink / raw)
  To: yangxingwu
  Cc: Simon Horman, pablo, netdev, lvs-devel, netfilter-devel,
	coreteam, linux-kernel, linux-doc, legend050709


	Hello,

On Fri, 29 Oct 2021, yangxingwu wrote:

> 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.

> Co-developed-by: Chuanqi Liu <legend050709@qq.com>
> Signed-off-by: Chuanqi Liu <legend050709@qq.com>
> Signed-off-by: yangxingwu <xingwu.yang@gmail.com>
> ---
>  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.

>  		bool old_ct = false, resched = false;

	And now you can move conn_reuse_mode here:

		int conn_reuse_mode = sysctl_conn_reuse_mode(ipvs);

>  		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 <ja@ssi.bg>

^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH v2] ipvs: Fix reuse connection if RS weight is 0
  2021-10-29 19:25 ` Julian Anastasov
@ 2021-10-30  2:42   ` yangxingwu
  0 siblings, 0 replies; 3+ messages in thread
From: yangxingwu @ 2021-10-30  2:42 UTC (permalink / raw)
  To: Julian Anastasov
  Cc: Simon Horman, Pablo Neira Ayuso, netdev, lvs-devel,
	netfilter-devel, coreteam, linux-kernel, linux-doc, legend050709

thanks Julian

I will do that

On Sat, Oct 30, 2021 at 3:25 AM Julian Anastasov <ja@ssi.bg> wrote:
>
>
>         Hello,
>
> On Fri, 29 Oct 2021, yangxingwu wrote:
>
> > 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.
>
> > Co-developed-by: Chuanqi Liu <legend050709@qq.com>
> > Signed-off-by: Chuanqi Liu <legend050709@qq.com>
> > Signed-off-by: yangxingwu <xingwu.yang@gmail.com>
> > ---
> >  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.
>
> >               bool old_ct = false, resched = false;
>
>         And now you can move conn_reuse_mode here:
>
>                 int conn_reuse_mode = sysctl_conn_reuse_mode(ipvs);
>
> >               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 <ja@ssi.bg>

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-10-30  2:42 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-10-29  3:26 [PATCH v2] ipvs: Fix reuse connection if RS weight is 0 yangxingwu
2021-10-29 19:25 ` Julian Anastasov
2021-10-30  2:42   ` yangxingwu

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