[lvc-project] [PATCH 6.1.y 2/2] netfilter: nft_set_pipapo: remove dirty flag

[Denis Zubov]

From: Florian Westphal <fw at strlen.de>

commit 532aec7e878b527fcee8877350ab5c5341789626 upstream.

After previous change:
 ->clone exists: ->dirty is always true
 ->clone == NULL ->dirty is always false

So remove this flag.

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

Needed in 6.1.y: since 16f3595c0441 (backport of 9df95785d3d8) the
dirty flag early return in nft_pipapo_commit() can strand a gc batch
on priv->gc_head between pipapo_gc_scan() and pipapo_gc_queue(),
which triggers the WARN_ON_ONCE() in nft_pipapo_destroy(). Context
adjusted for the deferred gc list.

Fixes: 16f3595c0441 ("netfilter: nft_set_pipapo: split gc into unlink and reclaim phase")
Signed-off-by: Denis Zubov <d.zubov at tssltd.ru>
---
 net/netfilter/nft_set_pipapo.c | 25 -------------------------
 net/netfilter/nft_set_pipapo.h |  2 --
 2 files changed, 27 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 9add83917f17..cee8d6afc91e 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -1273,7 +1273,6 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 	const u8 *start = (const u8 *)elem->key.val.data, *end;
 	struct nft_pipapo_elem *e = elem->priv, *dup;
 	struct nft_pipapo_match *m = pipapo_maybe_clone(set);
-	struct nft_pipapo *priv = nft_set_priv(set);
 	u8 genmask = nft_genmask_next(net);
 	u64 tstamp = nft_net_tstamp(net);
 	struct nft_pipapo_field *f;
@@ -1337,8 +1336,6 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 	}
 
 	/* Insert */
-	priv->dirty = true;
-
 	bsize_max = m->bsize_max;
 
 	nft_pipapo_for_each_field(f, i, m) {
@@ -1735,8 +1732,6 @@ static void pipapo_gc_scan(struct nft_set *set, struct nft_pipapo_match *m)
 		 * NFT_SET_ELEM_DEAD_BIT.
 		 */
 		if (__nft_set_elem_expired(&e->ext, tstamp)) {
-			priv->dirty = true;
-
 			if (!nft_trans_gc_space(gc)) {
 				gc = nft_trans_gc_alloc(set, 0, GFP_KERNEL);
 				if (!gc)
@@ -1850,13 +1845,9 @@ static void nft_pipapo_commit(struct nft_set *set)
 	if (time_after_eq(jiffies, priv->last_gc + nft_set_gc_interval(set)))
 		pipapo_gc_scan(set, priv->clone);
 
-	if (!priv->dirty)
-		return;
-
 	old = rcu_replace_pointer(priv->match, priv->clone,
 				  nft_pipapo_transaction_mutex_held(set));
 	priv->clone = NULL;
-	priv->dirty = false;
 
 	if (old)
 		call_rcu(&old->rcu, pipapo_reclaim_match);
@@ -1868,12 +1859,8 @@ static void nft_pipapo_abort(const struct nft_set *set)
 {
 	struct nft_pipapo *priv = nft_set_priv(set);
 
-	if (!priv->dirty)
-		return;
-
 	if (!priv->clone)
 		return;
-	priv->dirty = false;
 	pipapo_free_match(priv->clone);
 	priv->clone = NULL;
 }
@@ -2128,7 +2115,6 @@ static void nft_pipapo_remove(const struct net *net, const struct nft_set *set,
 			match_end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
 
 			if (last && f->mt[rulemap[i].to].e == e) {
-				priv->dirty = true;
 				pipapo_drop(m, rulemap);
 				return;
 			}
@@ -2319,22 +2305,11 @@ static int nft_pipapo_init(const struct nft_set *set,
 		f->mt = NULL;
 	}
 
-	/* Create an initial clone of matching data for next insertion */
-	priv->clone = pipapo_clone(m);
-	if (!priv->clone) {
-		err = -ENOMEM;
-		goto out_free;
-	}
-
-	priv->dirty = false;
-
 	INIT_LIST_HEAD(&priv->gc_head);
 	rcu_assign_pointer(priv->match, m);
 
 	return 0;
 
-out_free:
-	free_percpu(m->scratch);
 out_scratch:
 	kfree(m);
 
diff --git a/net/netfilter/nft_set_pipapo.h b/net/netfilter/nft_set_pipapo.h
index 949f4cd709b2..1116112bceb0 100644
--- a/net/netfilter/nft_set_pipapo.h
+++ b/net/netfilter/nft_set_pipapo.h
@@ -171,7 +171,6 @@ struct nft_pipapo_match {
  * @match:	Currently in-use matching data
  * @clone:	Copy where pending insertions and deletions are kept
  * @width:	Total bytes to be matched for one packet, including padding
- * @dirty:	Working copy has pending insertions or deletions
  * @last_gc:	Timestamp of last garbage collection run, jiffies
  * @gc_head:	list of nft_trans_gc to queue up for mem reclaim
  */
@@ -179,7 +178,6 @@ struct nft_pipapo {
 	struct nft_pipapo_match __rcu *match;
 	struct nft_pipapo_match *clone;
 	int width;
-	bool dirty;
 	unsigned long last_gc;
 	struct list_head gc_head;
 };
-- 
2.53.0