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Date: Mon, 6 May 2024 18:09:59 +0300 (EEST)
From: Julian Anastasov <ja@ssi.bg>
To: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
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>
Subject: Re: [PATCH v4 1/2] ipvs: add READ_ONCE barrier for
 ipvs->sysctl_amemthresh
In-Reply-To: <20240506141444.145946-1-aleksandr.mikhalitsyn@canonical.com>
Message-ID: <04e3e7bb-7f9f-816d-492f-1f17565719d8@ssi.bg>
References: <20240506141444.145946-1-aleksandr.mikhalitsyn@canonical.com>
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	Hello,

On Mon, 6 May 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.com>

	Looks good to me for net-next, 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 50b5dbe40eb8..e122fa367b81 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 *ipvs)
>  {
>  	struct sysinfo i;
>  	int availmem;
> +	int amemthresh;
>  	int nomem;
>  	int to_change = -1;
>  
> @@ -105,7 +106,8 @@ static void update_defense_level(struct netns_ipvs *ipvs)
>  	/* si_swapinfo(&i); */
>  	/* availmem = availmem - (i.totalswap - i.freeswap); */
>  
> -	nomem = (availmem < ipvs->sysctl_amemthresh);
> +	amemthresh = max(READ_ONCE(ipvs->sysctl_amemthresh), 0);
> +	nomem = (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 = ipvs->drop_counter
> -				= ipvs->sysctl_amemthresh /
> -				(ipvs->sysctl_amemthresh-availmem);
> +			ipvs->drop_counter = amemthresh / (amemthresh - availmem);
> +			ipvs->drop_rate = ipvs->drop_counter;
>  			ipvs->sysctl_drop_packet = 2;
>  		} else {
>  			ipvs->drop_rate = 0;
> @@ -155,9 +156,8 @@ static void update_defense_level(struct netns_ipvs *ipvs)
>  		break;
>  	case 2:
>  		if (nomem) {
> -			ipvs->drop_rate = ipvs->drop_counter
> -				= ipvs->sysctl_amemthresh /
> -				(ipvs->sysctl_amemthresh-availmem);
> +			ipvs->drop_counter = amemthresh / (amemthresh - availmem);
> +			ipvs->drop_rate = ipvs->drop_counter;
>  		} else {
>  			ipvs->drop_rate = 0;
>  			ipvs->sysctl_drop_packet = 1;
> -- 
> 2.34.1

Regards

--
Julian Anastasov <ja@ssi.bg>