From: Julian Anastasov <[email protected]>
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: [email protected]
Signed-off-by: Julian Anastasov <[email protected]>
Signed-off-by: Yizhou Zhao <[email protected]>
---
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 eb796e04eed6..c43b7e8368d0 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -993,6 +993,7 @@ 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 */
@@ -1909,6 +1910,8 @@ 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,
--
2.34.1
