[PATCH v2] netfilter: nf_tables: replace unnecessary use of list_for_each_entry_continue()

[PATCH v2] netfilter: nf_tables: replace unnecessary use of list_for_each_entry_continue()

[Jakob Koschel]

Since there is no way for list_for_each_entry_continue() to start
interating in the middle of the list they can be replaced with a call
to list_for_each_entry().

In preparation to limit the scope of the list iterator to the list
traversal loop, the list iterator variable 'rule' should not be used
past the loop.

v1->v2:
- also replace first usage of list_for_each_entry_continue() (Florian
Westphal)

Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
---
 net/netfilter/nf_tables_api.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index d71a33ae39b3..6a8239b25a66 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -8279,10 +8279,8 @@ static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *cha
 	if (chain->blob_next || !nft_is_active_next(net, chain))
 		return 0;

-	rule = list_entry(&chain->rules, struct nft_rule, list);
-
 	data_size = 0;
-	list_for_each_entry_continue(rule, &chain->rules, list) {
+	list_for_each_entry(rule, &chain->rules, list) {
 		if (nft_is_active_next(net, rule)) {
 			data_size += sizeof(*prule) + rule->dlen;
 			if (data_size > INT_MAX)
@@ -8299,7 +8297,7 @@ static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *cha
 	data_boundary = data + data_size;
 	size = 0;

-	list_for_each_entry_continue(rule, &chain->rules, list) {
+	list_for_each_entry(rule, &chain->rules, list) {
 		if (!nft_is_active_next(net, rule))
 			continue;


base-commit: f443e374ae131c168a065ea1748feac6b2e76613
--
2.25.1

Re: [PATCH v2] netfilter: nf_tables: replace unnecessary use of list_for_each_entry_continue()

[Pablo Neira Ayuso]

On Tue, Mar 22, 2022 at 11:56:44AM +0100, Jakob Koschel wrote:
> Since there is no way for list_for_each_entry_continue() to start
> interating in the middle of the list they can be replaced with a call
> to list_for_each_entry().
> 
> In preparation to limit the scope of the list iterator to the list
> traversal loop, the list iterator variable 'rule' should not be used
> past the loop.

Applied to nf-next, thanks