From 53315ac660b09f8128cd086e3ea0ed5ed5081d55 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 22 May 2019 23:35:11 +0200 Subject: [PATCH] netfilter: nf_tables: free base chain counters from worker No need to use synchronize_rcu() here, just swap the two pointers and have the release occur from work queue after commit has completed. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 28241e82fd15..2fed78b19abe 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1449,25 +1449,18 @@ static struct nft_stats __percpu *nft_stats_alloc(const struct nlattr *attr) return newstats; } -static void nft_chain_stats_replace(struct net *net, - struct nft_base_chain *chain, - struct nft_stats __percpu *newstats) +static void nft_chain_stats_replace(struct nft_trans *trans) { - struct nft_stats __percpu *oldstats; + struct nft_base_chain *chain = nft_base_chain(trans->ctx.chain); - if (newstats == NULL) + if (!nft_trans_chain_stats(trans)) return; - if (rcu_access_pointer(chain->stats)) { - oldstats = rcu_dereference_protected(chain->stats, - lockdep_commit_lock_is_held(net)); - rcu_assign_pointer(chain->stats, newstats); - synchronize_rcu(); - free_percpu(oldstats); - } else { - rcu_assign_pointer(chain->stats, newstats); + rcu_swap_protected(chain->stats, nft_trans_chain_stats(trans), + lockdep_commit_lock_is_held(trans->ctx.net)); + + if (!nft_trans_chain_stats(trans)) static_branch_inc(&nft_counters_enabled); - } } static void nf_tables_chain_free_chain_rules(struct nft_chain *chain) @@ -6360,9 +6353,9 @@ static void nft_chain_commit_update(struct nft_trans *trans) if (!nft_is_base_chain(trans->ctx.chain)) return; + nft_chain_stats_replace(trans); + basechain = nft_base_chain(trans->ctx.chain); - nft_chain_stats_replace(trans->ctx.net, basechain, - nft_trans_chain_stats(trans)); switch (nft_trans_chain_policy(trans)) { case NF_DROP: @@ -6379,6 +6372,7 @@ static void nft_commit_release(struct nft_trans *trans) nf_tables_table_destroy(&trans->ctx); break; case NFT_MSG_NEWCHAIN: + free_percpu(nft_trans_chain_stats(trans)); kfree(nft_trans_chain_name(trans)); break; case NFT_MSG_DELCHAIN: -- 2.20.1