1 files changed, 268 insertions, 104 deletions

diff --git a/net/openvswitch/meter.c b/net/openvswitch/meter.c
index 43849d752a1e..cc08e0403909 100644
--- a/net/openvswitch/meter.c
+++ b/net/openvswitch/meter.c
@@ -1,9 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2017 Nicira, Inc.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -22,8 +19,6 @@
 #include "datapath.h"
 #include "meter.h"
 
-#define METER_HASH_BUCKETS 1024
-
 static const struct nla_policy meter_policy[OVS_METER_ATTR_MAX + 1] = {
 	[OVS_METER_ATTR_ID] = { .type = NLA_U32, },
 	[OVS_METER_ATTR_KBPS] = { .type = NLA_FLAG },
@@ -42,6 +37,11 @@ static const struct nla_policy band_policy[OVS_BAND_ATTR_MAX + 1] = {
 	[OVS_BAND_ATTR_STATS] = { .len = sizeof(struct ovs_flow_stats) },
 };
 
+static u32 meter_hash(struct dp_meter_instance *ti, u32 id)
+{
+	return id % ti->n_meters;
+}
+
 static void ovs_meter_free(struct dp_meter *meter)
 {
 	if (!meter)
@@ -50,39 +50,160 @@ static void ovs_meter_free(struct dp_meter *meter)
 	kfree_rcu(meter, rcu);
 }
 
-static struct hlist_head *meter_hash_bucket(const struct datapath *dp,
-					    u32 meter_id)
-{
-	return &dp->meters[meter_id & (METER_HASH_BUCKETS - 1)];
-}
-
 /* Call with ovs_mutex or RCU read lock. */
-static struct dp_meter *lookup_meter(const struct datapath *dp,
+static struct dp_meter *lookup_meter(const struct dp_meter_table *tbl,
 				     u32 meter_id)
 {
+	struct dp_meter_instance *ti = rcu_dereference_ovsl(tbl->ti);
+	u32 hash = meter_hash(ti, meter_id);
 	struct dp_meter *meter;
-	struct hlist_head *head;
 
-	head = meter_hash_bucket(dp, meter_id);
-	hlist_for_each_entry_rcu(meter, head, dp_hash_node) {
-		if (meter->id == meter_id)
-			return meter;
-	}
+	meter = rcu_dereference_ovsl(ti->dp_meters[hash]);
+	if (meter && likely(meter->id == meter_id))
+		return meter;
+
 	return NULL;
 }
 
-static void attach_meter(struct datapath *dp, struct dp_meter *meter)
+static struct dp_meter_instance *dp_meter_instance_alloc(const u32 size)
+{
+	struct dp_meter_instance *ti;
+
+	ti = kvzalloc(struct_size(ti, dp_meters, size), GFP_KERNEL);
+	if (!ti)
+		return NULL;
+
+	ti->n_meters = size;
+
+	return ti;
+}
+
+static void dp_meter_instance_free(struct dp_meter_instance *ti)
+{
+	kvfree(ti);
+}
+
+static void dp_meter_instance_free_rcu(struct rcu_head *rcu)
+{
+	struct dp_meter_instance *ti;
+
+	ti = container_of(rcu, struct dp_meter_instance, rcu);
+	kvfree(ti);
+}
+
+static int
+dp_meter_instance_realloc(struct dp_meter_table *tbl, u32 size)
+{
+	struct dp_meter_instance *ti = rcu_dereference_ovsl(tbl->ti);
+	int n_meters = min(size, ti->n_meters);
+	struct dp_meter_instance *new_ti;
+	int i;
+
+	new_ti = dp_meter_instance_alloc(size);
+	if (!new_ti)
+		return -ENOMEM;
+
+	for (i = 0; i < n_meters; i++)
+		if (rcu_dereference_ovsl(ti->dp_meters[i]))
+			new_ti->dp_meters[i] = ti->dp_meters[i];
+
+	rcu_assign_pointer(tbl->ti, new_ti);
+	call_rcu(&ti->rcu, dp_meter_instance_free_rcu);
+
+	return 0;
+}
+
+static void dp_meter_instance_insert(struct dp_meter_instance *ti,
+				     struct dp_meter *meter)
+{
+	u32 hash;
+
+	hash = meter_hash(ti, meter->id);
+	rcu_assign_pointer(ti->dp_meters[hash], meter);
+}
+
+static void dp_meter_instance_remove(struct dp_meter_instance *ti,
+				     struct dp_meter *meter)
+{
+	u32 hash;
+
+	hash = meter_hash(ti, meter->id);
+	RCU_INIT_POINTER(ti->dp_meters[hash], NULL);
+}
+
+static int attach_meter(struct dp_meter_table *tbl, struct dp_meter *meter)
 {
-	struct hlist_head *head = meter_hash_bucket(dp, meter->id);
+	struct dp_meter_instance *ti = rcu_dereference_ovsl(tbl->ti);
+	u32 hash = meter_hash(ti, meter->id);
+	int err;
+
+	/* In generally, slots selected should be empty, because
+	 * OvS uses id-pool to fetch a available id.
+	 */
+	if (unlikely(rcu_dereference_ovsl(ti->dp_meters[hash])))
+		return -EBUSY;
+
+	dp_meter_instance_insert(ti, meter);
+
+	/* That function is thread-safe. */
+	tbl->count++;
+	if (tbl->count >= tbl->max_meters_allowed) {
+		err = -EFBIG;
+		goto attach_err;
+	}
+
+	if (tbl->count >= ti->n_meters &&
+	    dp_meter_instance_realloc(tbl, ti->n_meters * 2)) {
+		err = -ENOMEM;
+		goto attach_err;
+	}
 
-	hlist_add_head_rcu(&meter->dp_hash_node, head);
+	return 0;
+
+attach_err:
+	dp_meter_instance_remove(ti, meter);
+	tbl->count--;
+	return err;
 }
 
-static void detach_meter(struct dp_meter *meter)
+static int detach_meter(struct dp_meter_table *tbl, struct dp_meter *meter)
 {
+	struct dp_meter_instance *ti;
+
 	ASSERT_OVSL();
-	if (meter)
-		hlist_del_rcu(&meter->dp_hash_node);
+	if (!meter)
+		return 0;
+
+	ti = rcu_dereference_ovsl(tbl->ti);
+	dp_meter_instance_remove(ti, meter);
+
+	tbl->count--;
+
+	/* Shrink the meter array if necessary. */
+	if (ti->n_meters > DP_METER_ARRAY_SIZE_MIN &&
+	    tbl->count <= (ti->n_meters / 4)) {
+		int half_size = ti->n_meters / 2;
+		int i;
+
+		/* Avoid hash collision, don't move slots to other place.
+		 * Make sure there are no references of meters in array
+		 * which will be released.
+		 */
+		for (i = half_size; i < ti->n_meters; i++)
+			if (rcu_dereference_ovsl(ti->dp_meters[i]))
+				goto out;
+
+		if (dp_meter_instance_realloc(tbl, half_size))
+			goto shrink_err;
+	}
+
+out:
+	return 0;
+
+shrink_err:
+	dp_meter_instance_insert(ti, meter);
+	tbl->count++;
+	return -ENOMEM;
 }
 
 static struct sk_buff *
@@ -90,7 +211,7 @@ ovs_meter_cmd_reply_start(struct genl_info *info, u8 cmd,
 			  struct ovs_header **ovs_reply_header)
 {
 	struct sk_buff *skb;
-	struct ovs_header *ovs_header = info->userhdr;
+	struct ovs_header *ovs_header = genl_info_userhdr(info);
 
 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
 	if (!skb)
@@ -118,16 +239,15 @@ static int ovs_meter_cmd_reply_stats(struct sk_buff *reply, u32 meter_id,
 	if (nla_put_u32(reply, OVS_METER_ATTR_ID, meter_id))
 		goto error;
 
-	if (!meter)
-		return 0;
-
 	if (nla_put(reply, OVS_METER_ATTR_STATS,
-		    sizeof(struct ovs_flow_stats), &meter->stats) ||
-	    nla_put_u64_64bit(reply, OVS_METER_ATTR_USED, meter->used,
+		    sizeof(struct ovs_flow_stats), &meter->stats))
+		goto error;
+
+	if (nla_put_u64_64bit(reply, OVS_METER_ATTR_USED, meter->used,
 			      OVS_METER_ATTR_PAD))
 		goto error;
 
-	nla = nla_nest_start(reply, OVS_METER_ATTR_BANDS);
+	nla = nla_nest_start_noflag(reply, OVS_METER_ATTR_BANDS);
 	if (!nla)
 		goto error;
 
@@ -136,7 +256,7 @@ static int ovs_meter_cmd_reply_stats(struct sk_buff *reply, u32 meter_id,
 	for (i = 0; i < meter->n_bands; ++i, ++band) {
 		struct nlattr *band_nla;
 
-		band_nla = nla_nest_start(reply, OVS_BAND_ATTR_UNSPEC);
+		band_nla = nla_nest_start_noflag(reply, OVS_BAND_ATTR_UNSPEC);
 		if (!band_nla || nla_put(reply, OVS_BAND_ATTR_STATS,
 					 sizeof(struct ovs_flow_stats),
 					 &band->stats))
@@ -152,25 +272,39 @@ error:
 
 static int ovs_meter_cmd_features(struct sk_buff *skb, struct genl_info *info)
 {
-	struct sk_buff *reply;
+	struct ovs_header *ovs_header = genl_info_userhdr(info);
 	struct ovs_header *ovs_reply_header;
 	struct nlattr *nla, *band_nla;
-	int err;
+	struct sk_buff *reply;
+	struct datapath *dp;
+	int err = -EMSGSIZE;
 
 	reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_FEATURES,
 					  &ovs_reply_header);
 	if (IS_ERR(reply))
 		return PTR_ERR(reply);
 
-	if (nla_put_u32(reply, OVS_METER_ATTR_MAX_METERS, U32_MAX) ||
-	    nla_put_u32(reply, OVS_METER_ATTR_MAX_BANDS, DP_MAX_BANDS))
+	ovs_lock();
+	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
+	if (!dp) {
+		err = -ENODEV;
+		goto exit_unlock;
+	}
+
+	if (nla_put_u32(reply, OVS_METER_ATTR_MAX_METERS,
+			dp->meter_tbl.max_meters_allowed))
+		goto exit_unlock;
+
+	ovs_unlock();
+
+	if (nla_put_u32(reply, OVS_METER_ATTR_MAX_BANDS, DP_MAX_BANDS))
 		goto nla_put_failure;
 
-	nla = nla_nest_start(reply, OVS_METER_ATTR_BANDS);
+	nla = nla_nest_start_noflag(reply, OVS_METER_ATTR_BANDS);
 	if (!nla)
 		goto nla_put_failure;
 
-	band_nla = nla_nest_start(reply, OVS_BAND_ATTR_UNSPEC);
+	band_nla = nla_nest_start_noflag(reply, OVS_BAND_ATTR_UNSPEC);
 	if (!band_nla)
 		goto nla_put_failure;
 	/* Currently only DROP band type is supported. */
@@ -182,9 +316,10 @@ static int ovs_meter_cmd_features(struct sk_buff *skb, struct genl_info *info)
 	genlmsg_end(reply, ovs_reply_header);
 	return genlmsg_reply(reply, info);
 
+exit_unlock:
+	ovs_unlock();
 nla_put_failure:
 	nlmsg_free(reply);
-	err = -EMSGSIZE;
 	return err;
 }
 
@@ -206,7 +341,7 @@ static struct dp_meter *dp_meter_create(struct nlattr **a)
 			return ERR_PTR(-EINVAL);
 
 	/* Allocate and set up the meter before locking anything. */
-	meter = kzalloc(struct_size(meter, bands, n_bands), GFP_KERNEL);
+	meter = kzalloc(struct_size(meter, bands, n_bands), GFP_KERNEL_ACCOUNT);
 	if (!meter)
 		return ERR_PTR(-ENOMEM);
 
@@ -227,9 +362,9 @@ static struct dp_meter *dp_meter_create(struct nlattr **a)
 		struct nlattr *attr[OVS_BAND_ATTR_MAX + 1];
 		u32 band_max_delta_t;
 
-		err = nla_parse((struct nlattr **)&attr, OVS_BAND_ATTR_MAX,
-				nla_data(nla), nla_len(nla), band_policy,
-				NULL);
+		err = nla_parse_deprecated((struct nlattr **)&attr,
+					   OVS_BAND_ATTR_MAX, nla_data(nla),
+					   nla_len(nla), band_policy, NULL);
 		if (err)
 			goto exit_free_meter;
 
@@ -254,8 +389,8 @@ static struct dp_meter *dp_meter_create(struct nlattr **a)
 		 *
 		 * Start with a full bucket.
 		 */
-		band->bucket = (band->burst_size + band->rate) * 1000;
-		band_max_delta_t = band->bucket / band->rate;
+		band->bucket = band->burst_size * 1000ULL;
+		band_max_delta_t = div_u64(band->bucket, band->rate);
 		if (band_max_delta_t > meter->max_delta_t)
 			meter->max_delta_t = band_max_delta_t;
 		band++;
@@ -274,18 +409,18 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
 	struct dp_meter *meter, *old_meter;
 	struct sk_buff *reply;
 	struct ovs_header *ovs_reply_header;
-	struct ovs_header *ovs_header = info->userhdr;
+	struct ovs_header *ovs_header = genl_info_userhdr(info);
+	struct dp_meter_table *meter_tbl;
 	struct datapath *dp;
 	int err;
 	u32 meter_id;
 	bool failed;
 
-	if (!a[OVS_METER_ATTR_ID]) {
-		return -ENODEV;
-	}
+	if (!a[OVS_METER_ATTR_ID])
+		return -EINVAL;
 
 	meter = dp_meter_create(a);
-	if (IS_ERR_OR_NULL(meter))
+	if (IS_ERR(meter))
 		return PTR_ERR(meter);
 
 	reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_SET,
@@ -302,12 +437,18 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
 		goto exit_unlock;
 	}
 
+	meter_tbl = &dp->meter_tbl;
 	meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]);
 
-	/* Cannot fail after this. */
-	old_meter = lookup_meter(dp, meter_id);
-	detach_meter(old_meter);
-	attach_meter(dp, meter);
+	old_meter = lookup_meter(meter_tbl, meter_id);
+	err = detach_meter(meter_tbl, old_meter);
+	if (err)
+		goto exit_unlock;
+
+	err = attach_meter(meter_tbl, meter);
+	if (err)
+		goto exit_free_old_meter;
+
 	ovs_unlock();
 
 	/* Build response with the meter_id and stats from
@@ -329,6 +470,8 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
 	genlmsg_end(reply, ovs_reply_header);
 	return genlmsg_reply(reply, info);
 
+exit_free_old_meter:
+	ovs_meter_free(old_meter);
 exit_unlock:
 	ovs_unlock();
 	nlmsg_free(reply);
@@ -339,14 +482,14 @@ exit_free_meter:
 
 static int ovs_meter_cmd_get(struct sk_buff *skb, struct genl_info *info)
 {
-	struct nlattr **a = info->attrs;
-	u32 meter_id;
-	struct ovs_header *ovs_header = info->userhdr;
+	struct ovs_header *ovs_header = genl_info_userhdr(info);
 	struct ovs_header *ovs_reply_header;
+	struct nlattr **a = info->attrs;
+	struct dp_meter *meter;
+	struct sk_buff *reply;
 	struct datapath *dp;
+	u32 meter_id;
 	int err;
-	struct sk_buff *reply;
-	struct dp_meter *meter;
 
 	if (!a[OVS_METER_ATTR_ID])
 		return -EINVAL;
@@ -367,7 +510,7 @@ static int ovs_meter_cmd_get(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	/* Locate meter, copy stats. */
-	meter = lookup_meter(dp, meter_id);
+	meter = lookup_meter(&dp->meter_tbl, meter_id);
 	if (!meter) {
 		err = -ENOENT;
 		goto exit_unlock;
@@ -392,18 +535,17 @@ exit_unlock:
 
 static int ovs_meter_cmd_del(struct sk_buff *skb, struct genl_info *info)
 {
-	struct nlattr **a = info->attrs;
-	u32 meter_id;
-	struct ovs_header *ovs_header = info->userhdr;
+	struct ovs_header *ovs_header = genl_info_userhdr(info);
 	struct ovs_header *ovs_reply_header;
+	struct nlattr **a = info->attrs;
+	struct dp_meter *old_meter;
+	struct sk_buff *reply;
 	struct datapath *dp;
+	u32 meter_id;
 	int err;
-	struct sk_buff *reply;
-	struct dp_meter *old_meter;
 
 	if (!a[OVS_METER_ATTR_ID])
 		return -EINVAL;
-	meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]);
 
 	reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_DEL,
 					  &ovs_reply_header);
@@ -418,14 +560,19 @@ static int ovs_meter_cmd_del(struct sk_buff *skb, struct genl_info *info)
 		goto exit_unlock;
 	}
 
-	old_meter = lookup_meter(dp, meter_id);
+	meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]);
+	old_meter = lookup_meter(&dp->meter_tbl, meter_id);
 	if (old_meter) {
 		spin_lock_bh(&old_meter->lock);
 		err = ovs_meter_cmd_reply_stats(reply, meter_id, old_meter);
 		WARN_ON(err);
 		spin_unlock_bh(&old_meter->lock);
-		detach_meter(old_meter);
+
+		err = detach_meter(&dp->meter_tbl, old_meter);
+		if (err)
+			goto exit_unlock;
 	}
+
 	ovs_unlock();
 	ovs_meter_free(old_meter);
 	genlmsg_end(reply, ovs_reply_header);
@@ -445,16 +592,16 @@ exit_unlock:
 bool ovs_meter_execute(struct datapath *dp, struct sk_buff *skb,
 		       struct sw_flow_key *key, u32 meter_id)
 {
-	struct dp_meter *meter;
-	struct dp_meter_band *band;
 	long long int now_ms = div_u64(ktime_get_ns(), 1000 * 1000);
 	long long int long_delta_ms;
-	u32 delta_ms;
-	u32 cost;
+	struct dp_meter_band *band;
+	struct dp_meter *meter;
 	int i, band_exceeded_max = -1;
 	u32 band_exceeded_rate = 0;
+	u32 delta_ms;
+	u32 cost;
 
-	meter = lookup_meter(dp, meter_id);
+	meter = lookup_meter(&dp->meter_tbl, meter_id);
 	/* Do not drop the packet when there is no meter. */
 	if (!meter)
 		return false;
@@ -463,6 +610,14 @@ bool ovs_meter_execute(struct datapath *dp, struct sk_buff *skb,
 	spin_lock(&meter->lock);
 
 	long_delta_ms = (now_ms - meter->used); /* ms */
+	if (long_delta_ms < 0) {
+		/* This condition means that we have several threads fighting
+		 * for a meter lock, and the one who received the packets a
+		 * bit later wins. Assuming that all racing threads received
+		 * packets at the same time to avoid overflow.
+		 */
+		long_delta_ms = 0;
+	}
 
 	/* Make sure delta_ms will not be too large, so that bucket will not
 	 * wrap around below.
@@ -493,7 +648,7 @@ bool ovs_meter_execute(struct datapath *dp, struct sk_buff *skb,
 		long long int max_bucket_size;
 
 		band = &meter->bands[i];
-		max_bucket_size = (band->burst_size + band->rate) * 1000LL;
+		max_bucket_size = band->burst_size * 1000LL;
 
 		band->bucket += delta_ms * band->rate;
 		if (band->bucket > max_bucket_size)
@@ -524,29 +679,29 @@ bool ovs_meter_execute(struct datapath *dp, struct sk_buff *skb,
 	return false;
 }
 
-static struct genl_ops dp_meter_genl_ops[] = {
+static const struct genl_small_ops dp_meter_genl_ops[] = {
 	{ .cmd = OVS_METER_CMD_FEATURES,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.flags = 0,		  /* OK for unprivileged users. */
-		.policy = meter_policy,
 		.doit = ovs_meter_cmd_features
 	},
 	{ .cmd = OVS_METER_CMD_SET,
-		.flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
-					   *  privilege.
-					   */
-		.policy = meter_policy,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN
+					       *  privilege.
+					       */
 		.doit = ovs_meter_cmd_set,
 	},
 	{ .cmd = OVS_METER_CMD_GET,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.flags = 0,		  /* OK for unprivileged users. */
-		.policy = meter_policy,
 		.doit = ovs_meter_cmd_get,
 	},
 	{ .cmd = OVS_METER_CMD_DEL,
-		.flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
-					   *  privilege.
-					   */
-		.policy = meter_policy,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN
+					       *  privilege.
+					       */
 		.doit = ovs_meter_cmd_del
 	},
 };
@@ -560,10 +715,12 @@ struct genl_family dp_meter_genl_family __ro_after_init = {
 	.name = OVS_METER_FAMILY,
 	.version = OVS_METER_VERSION,
 	.maxattr = OVS_METER_ATTR_MAX,
+	.policy = meter_policy,
 	.netnsok = true,
 	.parallel_ops = true,
-	.ops = dp_meter_genl_ops,
-	.n_ops = ARRAY_SIZE(dp_meter_genl_ops),
+	.small_ops = dp_meter_genl_ops,
+	.n_small_ops = ARRAY_SIZE(dp_meter_genl_ops),
+	.resv_start_op = OVS_METER_CMD_GET + 1,
 	.mcgrps = &ovs_meter_multicast_group,
 	.n_mcgrps = 1,
 	.module = THIS_MODULE,
@@ -571,32 +728,39 @@ struct genl_family dp_meter_genl_family __ro_after_init = {
 
 int ovs_meters_init(struct datapath *dp)
 {
-	int i;
-
-	dp->meters = kmalloc_array(METER_HASH_BUCKETS,
-				   sizeof(struct hlist_head), GFP_KERNEL);
+	struct dp_meter_table *tbl = &dp->meter_tbl;
+	struct dp_meter_instance *ti;
+	unsigned long free_mem_bytes;
 
-	if (!dp->meters)
+	ti = dp_meter_instance_alloc(DP_METER_ARRAY_SIZE_MIN);
+	if (!ti)
 		return -ENOMEM;
 
-	for (i = 0; i < METER_HASH_BUCKETS; i++)
-		INIT_HLIST_HEAD(&dp->meters[i]);
+	/* Allow meters in a datapath to use ~3.12% of physical memory. */
+	free_mem_bytes = nr_free_buffer_pages() * (PAGE_SIZE >> 5);
+	tbl->max_meters_allowed = min(free_mem_bytes / sizeof(struct dp_meter),
+				      DP_METER_NUM_MAX);
+	if (!tbl->max_meters_allowed)
+		goto out_err;
+
+	rcu_assign_pointer(tbl->ti, ti);
+	tbl->count = 0;
 
 	return 0;
+
+out_err:
+	dp_meter_instance_free(ti);
+	return -ENOMEM;
 }
 
 void ovs_meters_exit(struct datapath *dp)
 {
+	struct dp_meter_table *tbl = &dp->meter_tbl;
+	struct dp_meter_instance *ti = rcu_dereference_raw(tbl->ti);
 	int i;
 
-	for (i = 0; i < METER_HASH_BUCKETS; i++) {
-		struct hlist_head *head = &dp->meters[i];
-		struct dp_meter *meter;
-		struct hlist_node *n;
-
-		hlist_for_each_entry_safe(meter, n, head, dp_hash_node)
-			kfree(meter);
-	}
+	for (i = 0; i < ti->n_meters; i++)
+		ovs_meter_free(rcu_dereference_raw(ti->dp_meters[i]));
 
-	kfree(dp->meters);
+	dp_meter_instance_free(ti);
 }