netfilter: nft_set_pipapo: prepare destroy function for on-demand clone

Once priv->clone can be NULL in case no insertions/removals occurred
in the last transaction we need to drop set elements from priv->match
if priv->clone is NULL.

While at it, condense this function by reusing the pipapo_free_match
helper instead of open-coded version.

The rcu_barrier() is removed, its not needed: old call_rcu instances
for pipapo_reclaim_match do not access struct nft_set.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 7b6d5d2d0d540962aad92a53d3f64e9014a08f5a..459e2dd5050c591e9989fb6251bc0aabccf0babe 100644 (file)
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -2326,33 +2326,18 @@ static void nft_pipapo_destroy(const struct nft_ctx *ctx,
 {
        struct nft_pipapo *priv = nft_set_priv(set);
        struct nft_pipapo_match *m;
-       int cpu;
 
        m = rcu_dereference_protected(priv->match, true);
-       if (m) {
-               rcu_barrier();
-
-               for_each_possible_cpu(cpu)
-                       pipapo_free_scratch(m, cpu);
-               free_percpu(m->scratch);
-               pipapo_free_fields(m);
-               kfree(m);
-               priv->match = NULL;
-       }
 
        if (priv->clone) {
-               m = priv->clone;
-
-               nft_set_pipapo_match_destroy(ctx, set, m);
-
-               for_each_possible_cpu(cpu)
-                       pipapo_free_scratch(priv->clone, cpu);
-               free_percpu(priv->clone->scratch);
-
-               pipapo_free_fields(priv->clone);
-               kfree(priv->clone);
+               nft_set_pipapo_match_destroy(ctx, set, priv->clone);
+               pipapo_free_match(priv->clone);
                priv->clone = NULL;
+       } else {
+               nft_set_pipapo_match_destroy(ctx, set, m);
        }
+
+       pipapo_free_match(m);
 }
 
 /**