From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.netfilter.org (mail.netfilter.org [217.70.190.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C5EF43B4B3; Mon, 10 Aug 2026 19:06:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.190.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786388803; cv=none; b=jdK+S8AuIO0xpQ2z059bBB5577ie/Fxcacdw0KbO2eBgqMjclBn5j8uhVgEbFUGFLzopIsZVrPG/+4JaVkKW1cqAQ+URy9pqbfJGY8dGvUf+v5+n8L3RpQ9/CgMv7BUpOJsHyTQDRFUCl5BDgbaqCiHj3v5Nvp9vgnjAp8ESR3Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786388803; c=relaxed/simple; bh=AACnIXax3fDGBPnqWpLacestezF3kBB08pa/SuWzWVw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CBsPpW6/t4e+y13N3EqjmUrP1r9ENOtr84yZgw9ZHcvUsmTW3KjFCdXEmtTQ+qz9DoB1XzoFonG9X3vXkWUaF6ubgfRxR7I0/F5Wvc7DyVC7883Um74zYxOVJg6plLN2N0BgW/ljc2dIa+M/TcEFP/DLOy8qOFGEF4rwhp99Qm0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b=C1Oq30zX; arc=none smtp.client-ip=217.70.190.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b="C1Oq30zX" Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id 897606028E; Mon, 10 Aug 2026 21:06:38 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1786388799; bh=RapDeowCfsFdfGorRVjwASMw9nzxQb9kj4Y6bRbgoqo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C1Oq30zXBG344laZfs6lT7soatTg7GVphyitduSBbX61vT/3KKgulaTGKaueE4obz YDY2GkNA8t34vzuniAdEgr8d6ZALNN2p+L57ZvMRD9LXHoZVX5DxgYGxduZP4J6+Zn KmpQfwAbYb3q1RkK9N8MqgyxeyLmIj79hYypAUmtWtaLsjKBO47Hb/Rp+noZqVGgn/ qFP275NmfP59JaopzCDHKl8BtHg1+38FQDl5MAc8kCd58Grht70gFrcZLmEZPv1LGS GX06j8OGfKdQ8z1xHCTte+qXpEE4lL9Y8FOE8374Y+pTxpBzSJlHOuUAiVw7wZXHPq qbxpjanbTTVmg== From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, horms@kernel.org, fw@strlen.de, ja@ssi.bg Subject: [PATCH net 04/13] ipvs: properly update the overload flag on dest edit Date: Mon, 10 Aug 2026 21:06:12 +0200 Message-ID: <20260810190621.894119-5-pablo@netfilter.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260810190621.894119-1-pablo@netfilter.org> References: <20260810190621.894119-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Julian Anastasov The upper/lower connection thresholds for dest can be changed, so use ip_vs_dest_update_overload() to properly update the dest overload flag. The thresholds were not limited, fit them in the 0 .. INT_MAX range as already done in ipvsadm. As the thresholds are also read when connections are created and expired, use WRITE_ONCE/READ_ONCE to access them. As the lower threshold is optional, use (u - (u >> 2)) to calculate the 75% default value based on the upper threshold by preserving the integer rounding, as suggested by Yizhou Zhao. Trigger flag update when totalconns reaches one of the thresholds and use dst_lock to serialize the updating. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Julian Anastasov Signed-off-by: Yizhou Zhao Signed-off-by: Pablo Neira Ayuso --- include/net/ip_vs.h | 3 ++ net/netfilter/ipvs/ip_vs_conn.c | 27 +++++-------- net/netfilter/ipvs/ip_vs_ctl.c | 67 +++++++++++++++++++++++++++++---- 3 files changed, 72 insertions(+), 25 deletions(-) diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index 11f430646db8..e99382930617 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -991,6 +991,7 @@ struct ip_vs_dest { atomic_t persistconns; /* persistent connections */ __u32 u_threshold; /* upper threshold */ __u32 l_threshold; /* lower threshold */ + __u32 l_threshold_val;/* used lower threshold */ /* for destination cache */ spinlock_t dst_lock; /* lock of dst_cache */ @@ -1907,6 +1908,8 @@ static inline void ip_vs_dest_put_and_free(struct ip_vs_dest *dest) kfree(dest); } +void ip_vs_dest_update_overload(struct ip_vs_dest *dest, int mode); + /* IPVS sync daemon data and function prototypes * (from ip_vs_sync.c) */ diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c index 4d0a6f718ced..abf52a226fee 100644 --- a/net/netfilter/ipvs/ip_vs_conn.c +++ b/net/netfilter/ipvs/ip_vs_conn.c @@ -1141,22 +1141,22 @@ ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest) /* Update the connection counters */ if (!(flags & IP_VS_CONN_F_TEMPLATE)) { + int tc; + /* It is a normal connection, so modify the counters * according to the flags, later the protocol can * update them on state change */ if (!(flags & IP_VS_CONN_F_INACTIVE)) atomic_inc(&dest->activeconns); - atomic_inc(&dest->totalconns); + tc = atomic_inc_return(&dest->totalconns); + if (tc == READ_ONCE(dest->u_threshold)) + ip_vs_dest_update_overload(dest, 1); } else { /* It is a persistent connection/template, so increase the persistent connection counter */ atomic_inc(&dest->persistconns); } - - if (dest->u_threshold != 0 && - atomic_read(&dest->totalconns) >= dest->u_threshold) - dest->flags |= IP_VS_DEST_F_OVERLOAD; } @@ -1237,27 +1237,20 @@ static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp) /* Update the connection counters */ if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) { + int tc; + /* It is a normal connection, so decrease the counters */ if (!(cp->flags & IP_VS_CONN_F_INACTIVE)) atomic_dec(&dest->activeconns); - atomic_dec(&dest->totalconns); + tc = atomic_fetch_dec(&dest->totalconns); + if (tc == READ_ONCE(dest->l_threshold_val)) + ip_vs_dest_update_overload(dest, -1); } else { /* It is a persistent connection/template, so decrease the persistent connection counter */ atomic_dec(&dest->persistconns); } - if (dest->l_threshold != 0) { - if (atomic_read(&dest->totalconns) < dest->l_threshold) - dest->flags &= ~IP_VS_DEST_F_OVERLOAD; - } else if (dest->u_threshold != 0) { - if (atomic_read(&dest->totalconns) * 4 < dest->u_threshold * 3) - dest->flags &= ~IP_VS_DEST_F_OVERLOAD; - } else { - if (dest->flags & IP_VS_DEST_F_OVERLOAD) - dest->flags &= ~IP_VS_DEST_F_OVERLOAD; - } - ip_vs_dest_put(dest); } diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 45f534427d23..974773642af8 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -1304,6 +1304,40 @@ void ip_vs_stats_free(struct ip_vs_stats *stats) } } +/* Update overload flag based on number of dest conns and lower/upper + * connection thresholds: + * - conns reach u_threshold and exceed it: set the flag + * - conns go below l_threshold (or 75% of u_threshold): clear the flag + */ +static void __ip_vs_dest_update_overload(struct ip_vs_dest *dest, int mode) +{ + int conns; + u32 l, u; + + lockdep_assert_held(&dest->dst_lock); + u = READ_ONCE(dest->u_threshold); + if (!u) + goto unset; + l = READ_ONCE(dest->l_threshold_val); + conns = atomic_read(&dest->totalconns); + if (conns >= (mode > 0 ? l : u)) { + dest->flags |= IP_VS_DEST_F_OVERLOAD; + return; + } + if (conns >= (mode < 0 ? u : l)) + return; + +unset: + dest->flags &= ~IP_VS_DEST_F_OVERLOAD; +} + +void ip_vs_dest_update_overload(struct ip_vs_dest *dest, int mode) +{ + spin_lock_bh(&dest->dst_lock); + __ip_vs_dest_update_overload(dest, mode); + spin_unlock_bh(&dest->dst_lock); +} + /* * Update a destination in the given service */ @@ -1370,10 +1404,19 @@ __ip_vs_update_dest(struct ip_vs_service *svc, struct ip_vs_dest *dest, /* set the dest status flags */ dest->flags |= IP_VS_DEST_F_AVAILABLE; - if (udest->u_threshold == 0 || udest->u_threshold > dest->u_threshold) - dest->flags &= ~IP_VS_DEST_F_OVERLOAD; - dest->u_threshold = udest->u_threshold; - dest->l_threshold = udest->l_threshold; + if (READ_ONCE(dest->u_threshold) != udest->u_threshold || + READ_ONCE(dest->l_threshold) != udest->l_threshold) { + spin_lock_bh(&dest->dst_lock); + WRITE_ONCE(dest->u_threshold, udest->u_threshold); + WRITE_ONCE(dest->l_threshold, udest->l_threshold); + /* Low threshold defaults to 75% of upper threshold */ + WRITE_ONCE(dest->l_threshold_val, + udest->l_threshold ? : + (udest->u_threshold - + (udest->u_threshold >> 2))); + __ip_vs_dest_update_overload(dest, 0); + spin_unlock_bh(&dest->dst_lock); + } dest->af = udest->af; @@ -1486,6 +1529,9 @@ ip_vs_add_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest) return -ERANGE; } + if (udest->u_threshold > INT_MAX) + return -EINVAL; + if (udest->tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GUE) { if (udest->tun_port == 0) { pr_err("%s(): tunnel port is zero\n", __func__); @@ -1559,6 +1605,9 @@ ip_vs_edit_dest(struct ip_vs_service *svc, struct ip_vs_dest_user_kern *udest) return -ERANGE; } + if (udest->u_threshold > INT_MAX) + return -EINVAL; + if (udest->tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GUE) { if (udest->tun_port == 0) { pr_err("%s(): tunnel port is zero\n", __func__); @@ -3667,8 +3716,8 @@ __ip_vs_get_dest_entries(struct netns_ipvs *ipvs, const struct ip_vs_get_dests * entry.port = dest->port; entry.conn_flags = atomic_read(&dest->conn_flags); entry.weight = atomic_read(&dest->weight); - entry.u_threshold = dest->u_threshold; - entry.l_threshold = dest->l_threshold; + entry.u_threshold = READ_ONCE(dest->u_threshold); + entry.l_threshold = READ_ONCE(dest->l_threshold); entry.activeconns = atomic_read(&dest->activeconns); entry.inactconns = ip_vs_dest_inactconns(dest); entry.persistconns = atomic_read(&dest->persistconns); @@ -4277,8 +4326,10 @@ static int ip_vs_genl_fill_dest(struct sk_buff *skb, struct ip_vs_dest *dest) dest->tun_port) || nla_put_u16(skb, IPVS_DEST_ATTR_TUN_FLAGS, dest->tun_flags) || - nla_put_u32(skb, IPVS_DEST_ATTR_U_THRESH, dest->u_threshold) || - nla_put_u32(skb, IPVS_DEST_ATTR_L_THRESH, dest->l_threshold) || + nla_put_u32(skb, IPVS_DEST_ATTR_U_THRESH, + READ_ONCE(dest->u_threshold)) || + nla_put_u32(skb, IPVS_DEST_ATTR_L_THRESH, + READ_ONCE(dest->l_threshold)) || nla_put_u32(skb, IPVS_DEST_ATTR_ACTIVE_CONNS, atomic_read(&dest->activeconns)) || nla_put_u32(skb, IPVS_DEST_ATTR_INACT_CONNS, -- 2.47.3