diff mbox series

[nf-next] netfilter: nf_tables: do not remove elements if set backend implements .abort

Message ID 20240715141556.44047-1-pablo@netfilter.org
State Accepted
Headers show
Series [nf-next] netfilter: nf_tables: do not remove elements if set backend implements .abort | expand

Commit Message

Pablo Neira Ayuso July 15, 2024, 2:15 p.m. UTC
pipapo set backend maintains two copies of the datastructure, removing
the elements from the copy that is going to be discarded slows down
the abort path significantly, from several minutes to few seconds after
this patch.

This patch was previously reverted by

  f86fb94011ae ("netfilter: nf_tables: revert do not remove elements if set backend implements .abort")

but it is now possible since recent work by Florian Westphal to perform
on-demand clone from insert/remove path:

  532aec7e878b ("netfilter: nft_set_pipapo: remove dirty flag")
  3f1d886cc7c3 ("netfilter: nft_set_pipapo: move cloning of match info to insert/removal path")
  a238106703ab ("netfilter: nft_set_pipapo: prepare pipapo_get helper for on-demand clone")
  c5444786d0ea ("netfilter: nft_set_pipapo: merge deactivate helper into caller")
  6c108d9bee44 ("netfilter: nft_set_pipapo: prepare walk function for on-demand clone")
  8b8a2417558c ("netfilter: nft_set_pipapo: prepare destroy function for on-demand clone")
  80efd2997fb9 ("netfilter: nft_set_pipapo: make pipapo_clone helper return NULL")
  a590f4760922 ("netfilter: nft_set_pipapo: move prove_locking helper around")

after this series, the clone is fully released once aborted, no need to
take it back to previous state. Thus, no stale reference to elements can
occur.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Pablo Neira Ayuso Aug. 19, 2024, 4:54 p.m. UTC | #1
On Mon, Jul 15, 2024 at 04:15:56PM +0200, Pablo Neira Ayuso wrote:
> pipapo set backend maintains two copies of the datastructure, removing
> the elements from the copy that is going to be discarded slows down
> the abort path significantly, from several minutes to few seconds after
> this patch.
> 
> This patch was previously reverted by
> 
>   f86fb94011ae ("netfilter: nf_tables: revert do not remove elements if set backend implements .abort")
> 
> but it is now possible since recent work by Florian Westphal to perform
> on-demand clone from insert/remove path:
> 
>   532aec7e878b ("netfilter: nft_set_pipapo: remove dirty flag")
>   3f1d886cc7c3 ("netfilter: nft_set_pipapo: move cloning of match info to insert/removal path")
>   a238106703ab ("netfilter: nft_set_pipapo: prepare pipapo_get helper for on-demand clone")
>   c5444786d0ea ("netfilter: nft_set_pipapo: merge deactivate helper into caller")
>   6c108d9bee44 ("netfilter: nft_set_pipapo: prepare walk function for on-demand clone")
>   8b8a2417558c ("netfilter: nft_set_pipapo: prepare destroy function for on-demand clone")
>   80efd2997fb9 ("netfilter: nft_set_pipapo: make pipapo_clone helper return NULL")
>   a590f4760922 ("netfilter: nft_set_pipapo: move prove_locking helper around")
> 
> after this series, the clone is fully released once aborted, no need to
> take it back to previous state. Thus, no stale reference to elements can
> occur.

I have now rescued this patch and place it in nf-next.
diff mbox series

Patch

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 70d0bad029fd..f1b5bfe18691 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -10713,7 +10713,10 @@  static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
 				break;
 			}
 			te = nft_trans_container_elem(trans);
-			nft_setelem_remove(net, te->set, te->elem_priv);
+			if (!te->set->ops->abort ||
+			    nft_setelem_is_catchall(te->set, te->elem_priv))
+				nft_setelem_remove(net, te->set, te->elem_priv);
+
 			if (!nft_setelem_is_catchall(te->set, te->elem_priv))
 				atomic_dec(&te->set->nelems);