Commit 0c45e769 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nft_counter: convert it to use per-cpu counters 



This patch converts the existing seqlock to per-cpu counters.

Suggested-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Suggested-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent d92cff89

net/netfilter/nft_counter.c

+69 −28
Original line number Diff line number Diff line
@@ -18,39 +18,59 @@ 
#include <net/netfilter/nf_tables.h>



struct nft_counter {

	seqlock_t	lock;

	u64		bytes;

	u64		packets;

};



struct nft_counter_percpu {

	struct nft_counter	counter;

	struct u64_stats_sync	syncp;

};



struct nft_counter_percpu_priv {

	struct nft_counter_percpu __percpu *counter;

};



static void nft_counter_eval(const struct nft_expr *expr,

			     struct nft_regs *regs,

			     const struct nft_pktinfo *pkt)

{

	struct nft_counter *priv = nft_expr_priv(expr);



	write_seqlock_bh(&priv->lock);

	priv->bytes += pkt->skb->len;

	priv->packets++;

	write_sequnlock_bh(&priv->lock);

	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);

	struct nft_counter_percpu *this_cpu;



	local_bh_disable();

	this_cpu = this_cpu_ptr(priv->counter);

	u64_stats_update_begin(&this_cpu->syncp);

	this_cpu->counter.bytes += pkt->skb->len;

	this_cpu->counter.packets++;

	u64_stats_update_end(&this_cpu->syncp);

	local_bh_enable();

}



static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr)

{

	struct nft_counter *priv = nft_expr_priv(expr);

	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);

	struct nft_counter_percpu *cpu_stats;

	struct nft_counter total;

	u64 bytes, packets;

	unsigned int seq;

	u64 bytes;

	u64 packets;

	int cpu;



	memset(&total, 0, sizeof(total));

	for_each_possible_cpu(cpu) {

		cpu_stats = per_cpu_ptr(priv->counter, cpu);

		do {

		seq = read_seqbegin(&priv->lock);

		bytes	= priv->bytes;

		packets	= priv->packets;

	} while (read_seqretry(&priv->lock, seq));

			seq	= u64_stats_fetch_begin_irq(&cpu_stats->syncp);

			bytes	= cpu_stats->counter.bytes;

			packets	= cpu_stats->counter.packets;

		} while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, seq));



	if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(bytes)))

		goto nla_put_failure;

	if (nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(packets)))

		total.packets += packets;

		total.bytes += bytes;

	}



	if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes)) ||

	    nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(total.packets)))

		goto nla_put_failure;

	return 0;
@@ -67,23 +87,44 @@ static int nft_counter_init(const struct nft_ctx *ctx, 
			    const struct nft_expr *expr,

			    const struct nlattr * const tb[])

{

	struct nft_counter *priv = nft_expr_priv(expr);

	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);

	struct nft_counter_percpu __percpu *cpu_stats;

	struct nft_counter_percpu *this_cpu;



	cpu_stats = netdev_alloc_pcpu_stats(struct nft_counter_percpu);

	if (cpu_stats == NULL)

		return ENOMEM;



	preempt_disable();

	this_cpu = this_cpu_ptr(cpu_stats);

	if (tb[NFTA_COUNTER_PACKETS]) {

	        this_cpu->counter.packets =

			be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));

	}

	if (tb[NFTA_COUNTER_BYTES]) {

		this_cpu->counter.bytes =

			be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));

	}

	preempt_enable();

	priv->counter = cpu_stats;

	return 0;

}



	if (tb[NFTA_COUNTER_PACKETS])

	        priv->packets = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS]));

	if (tb[NFTA_COUNTER_BYTES])

		priv->bytes = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));

static void nft_counter_destroy(const struct nft_ctx *ctx,

				const struct nft_expr *expr)

{

	struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);



	seqlock_init(&priv->lock);

	return 0;

	free_percpu(priv->counter);

}



static struct nft_expr_type nft_counter_type;

static const struct nft_expr_ops nft_counter_ops = {

	.type		= &nft_counter_type,

	.size		= NFT_EXPR_SIZE(sizeof(struct nft_counter)),

	.size		= NFT_EXPR_SIZE(sizeof(struct nft_counter_percpu_priv)),

	.eval		= nft_counter_eval,

	.init		= nft_counter_init,

	.destroy	= nft_counter_destroy,

	.dump		= nft_counter_dump,

};