netdev - [PATCH net-next 2/9] netfilter: nf_tables: always increment set element count

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Message-Id: <20230518100759.84858-3-fw@strlen.de>
Date: Thu, 18 May 2023 12:07:52 +0200
From: Florian Westphal <fw@...len.de>
To: <netdev@...r.kernel.org>
Cc: Jakub Kicinski <kuba@...nel.org>,
	Eric Dumazet <edumazet@...gle.com>,
	Paolo Abeni <pabeni@...hat.com>,
	"David S. Miller" <davem@...emloft.net>,
	netfilter-devel <netfilter-devel@...r.kernel.org>
Subject: [PATCH net-next 2/9] netfilter: nf_tables: always increment set element count

At this time, set->nelems counter only increments when the set has
a maximum size.

All set elements decrement the counter unconditionally, this is
confusing.

Increment the counter unconditionally to make this symmetrical.
This would also allow changing the set maximum size after set creation
in a later patch.

Signed-off-by: Florian Westphal <fw@...len.de>
---
 net/netfilter/nf_tables_api.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 59fb8320ab4d..7a61de80a8d1 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6541,10 +6541,13 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 		goto err_element_clash;
 	}
 
-	if (!(flags & NFT_SET_ELEM_CATCHALL) && set->size &&
-	    !atomic_add_unless(&set->nelems, 1, set->size + set->ndeact)) {
-		err = -ENFILE;
-		goto err_set_full;
+	if (!(flags & NFT_SET_ELEM_CATCHALL)) {
+		unsigned int max = set->size ? set->size + set->ndeact : UINT_MAX;
+
+		if (!atomic_add_unless(&set->nelems, 1, max)) {
+			err = -ENFILE;
+			goto err_set_full;
+		}
 	}
 
 	nft_trans_elem(trans) = elem;
-- 
2.40.1