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netfilter: nf_tables: defer all object release via rcu

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Now that all objects are released in the reverse order via the
transaction infrastructure, we can enqueue the release via
call_rcu to save one synchronize_rcu. For small rule-sets loaded
via nft -f, it now takes around 50ms less here.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2014-04-10 00:31:10 +02:00
commit c7c32e72cb
2 changed files with 56 additions and 39 deletions
Download patch file Download diff file Expand all files Collapse all files

2
include/net/netfilter/nf_tables.h
View file

@ -393,12 +393,14 @@ struct nft_rule {
/**
* struct nft_trans - nf_tables object update in transaction
*
* @rcu_head: rcu head to defer release of transaction data
* @list: used internally
* @msg_type: message type
* @ctx: transaction context
* @data: internal information related to the transaction
*/
struct nft_trans {
struct rcu_head rcu_head;
struct list_head list;
int msg_type;
struct nft_ctx ctx;

93
net/netfilter/nf_tables_api.c
View file

@ -3298,6 +3298,30 @@ static void nft_chain_commit_update(struct nft_trans *trans)
}
}
/* Schedule objects for release via rcu to make sure no packets are accesing
* removed rules.
*/
static void nf_tables_commit_release_rcu(struct rcu_head *rt)
{
struct nft_trans *trans = container_of(rt, struct nft_trans, rcu_head);
switch (trans->msg_type) {
case NFT_MSG_DELTABLE:
nf_tables_table_destroy(&trans->ctx);
break;
case NFT_MSG_DELCHAIN:
nf_tables_chain_destroy(trans->ctx.chain);
break;
case NFT_MSG_DELRULE:
nf_tables_rule_destroy(&trans->ctx, nft_trans_rule(trans));
break;
case NFT_MSG_DELSET:
nft_set_destroy(nft_trans_set(trans));
break;
}
kfree(trans);
}
static int nf_tables_commit(struct sk_buff *skb)
{
struct net *net = sock_net(skb->sk);
@ -3397,32 +3421,39 @@ static int nf_tables_commit(struct sk_buff *skb)
}
}
/* Make sure we don't see any packet traversing old rules */
synchronize_rcu();
/* Now we can safely release unused old rules */
list_for_each_entry_safe(trans, next, &net->nft.commit_list, list) {
switch (trans->msg_type) {
case NFT_MSG_DELTABLE:
nf_tables_table_destroy(&trans->ctx);
break;
case NFT_MSG_DELCHAIN:
nf_tables_chain_destroy(trans->ctx.chain);
break;
case NFT_MSG_DELRULE:
nf_tables_rule_destroy(&trans->ctx,
nft_trans_rule(trans));
break;
case NFT_MSG_DELSET:
nft_set_destroy(nft_trans_set(trans));
break;
}
nft_trans_destroy(trans);
list_del(&trans->list);
trans->ctx.nla = NULL;
call_rcu(&trans->rcu_head, nf_tables_commit_release_rcu);
}
return 0;
}
/* Schedule objects for release via rcu to make sure no packets are accesing
* aborted rules.
*/
static void nf_tables_abort_release_rcu(struct rcu_head *rt)
{
struct nft_trans *trans = container_of(rt, struct nft_trans, rcu_head);
switch (trans->msg_type) {
case NFT_MSG_NEWTABLE:
nf_tables_table_destroy(&trans->ctx);
break;
case NFT_MSG_NEWCHAIN:
nf_tables_chain_destroy(trans->ctx.chain);
break;
case NFT_MSG_NEWRULE:
nf_tables_rule_destroy(&trans->ctx, nft_trans_rule(trans));
break;
case NFT_MSG_NEWSET:
nft_set_destroy(nft_trans_set(trans));
break;
}
kfree(trans);
}
static int nf_tables_abort(struct sk_buff *skb)
{
struct net *net = sock_net(skb->sk);
@ -3495,26 +3526,10 @@ static int nf_tables_abort(struct sk_buff *skb)
}
}
/* Make sure we don't see any packet accessing aborted rules */
synchronize_rcu();
list_for_each_entry_safe(trans, next, &net->nft.commit_list, list) {
switch (trans->msg_type) {
case NFT_MSG_NEWTABLE:
nf_tables_table_destroy(&trans->ctx);
break;
case NFT_MSG_NEWCHAIN:
nf_tables_chain_destroy(trans->ctx.chain);
break;
case NFT_MSG_NEWRULE:
nf_tables_rule_destroy(&trans->ctx,
nft_trans_rule(trans));
break;
case NFT_MSG_NEWSET:
nft_set_destroy(nft_trans_set(trans));
break;
}
nft_trans_destroy(trans);
list_del(&trans->list);
trans->ctx.nla = NULL;
call_rcu(&trans->rcu_head, nf_tables_abort_release_rcu);
}
return 0;