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From: Aleksandr Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Date: Mon, 22 Apr 2024 09:34:51 +0200
Message-ID: <CAEivzxejY7s_vNYbN4HJBT-RGrkYx7x1L4rfir-0EM+7EuPKew@mail.gmail.com>
Subject: Re: [PATCH net-next v3 1/2] ipvs: add READ_ONCE barrier for ipvs->sysctl_amemthresh
To: Julian Anastasov <ja@ssi.bg>
Cc: horms@verge.net.au, netdev@vger.kernel.org, lvs-devel@vger.kernel.org, 
	netfilter-devel@vger.kernel.org, linux-kernel@vger.kernel.org, 
	Pablo Neira Ayuso <pablo@netfilter.org>, Jozsef Kadlecsik <kadlec@netfilter.org>, 
	Florian Westphal <fw@strlen.de>
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On Sun, Apr 21, 2024 at 1:06=E2=80=AFPM Julian Anastasov <ja@ssi.bg> wrote:
>
>
>         Hello,

Dear Julian,

Thanks a lot for the fast review and suggestions!

Kind regards,
Alex

>
> On Thu, 18 Apr 2024, Alexander Mikhalitsyn wrote:
>
> > Cc: Julian Anastasov <ja@ssi.bg>
> > Cc: Simon Horman <horms@verge.net.au>
> > Cc: Pablo Neira Ayuso <pablo@netfilter.org>
> > Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
> > Cc: Florian Westphal <fw@strlen.de>
> > Suggested-by: Julian Anastasov <ja@ssi.bg>
> > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.c=
om>
>
>         Looks good to me, thanks!
>
> Acked-by: Julian Anastasov <ja@ssi.bg>
>
> > ---
> >  net/netfilter/ipvs/ip_vs_ctl.c | 14 +++++++-------
> >  1 file changed, 7 insertions(+), 7 deletions(-)
> >
> > diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_=
ctl.c
> > index 143a341bbc0a..32be24f0d4e4 100644
> > --- a/net/netfilter/ipvs/ip_vs_ctl.c
> > +++ b/net/netfilter/ipvs/ip_vs_ctl.c
> > @@ -94,6 +94,7 @@ static void update_defense_level(struct netns_ipvs *i=
pvs)
> >  {
> >       struct sysinfo i;
> >       int availmem;
> > +     int amemthresh;
> >       int nomem;
> >       int to_change =3D -1;
> >
> > @@ -105,7 +106,8 @@ static void update_defense_level(struct netns_ipvs =
*ipvs)
> >       /* si_swapinfo(&i); */
> >       /* availmem =3D availmem - (i.totalswap - i.freeswap); */
> >
> > -     nomem =3D (availmem < ipvs->sysctl_amemthresh);
> > +     amemthresh =3D max(READ_ONCE(ipvs->sysctl_amemthresh), 0);
> > +     nomem =3D (availmem < amemthresh);
> >
> >       local_bh_disable();
> >
> > @@ -145,9 +147,8 @@ static void update_defense_level(struct netns_ipvs =
*ipvs)
> >               break;
> >       case 1:
> >               if (nomem) {
> > -                     ipvs->drop_rate =3D ipvs->drop_counter
> > -                             =3D ipvs->sysctl_amemthresh /
> > -                             (ipvs->sysctl_amemthresh-availmem);
> > +                     ipvs->drop_counter =3D amemthresh / (amemthresh -=
 availmem);
> > +                     ipvs->drop_rate =3D ipvs->drop_counter;
> >                       ipvs->sysctl_drop_packet =3D 2;
> >               } else {
> >                       ipvs->drop_rate =3D 0;
> > @@ -155,9 +156,8 @@ static void update_defense_level(struct netns_ipvs =
*ipvs)
> >               break;
> >       case 2:
> >               if (nomem) {
> > -                     ipvs->drop_rate =3D ipvs->drop_counter
> > -                             =3D ipvs->sysctl_amemthresh /
> > -                             (ipvs->sysctl_amemthresh-availmem);
> > +                     ipvs->drop_counter =3D amemthresh / (amemthresh -=
 availmem);
> > +                     ipvs->drop_rate =3D ipvs->drop_counter;
> >               } else {
> >                       ipvs->drop_rate =3D 0;
> >                       ipvs->sysctl_drop_packet =3D 1;
> > --
> > 2.34.1
>
> Regards
>
> --
> Julian Anastasov <ja@ssi.bg>
>