Re: [PATCH RFC batadv v2 4/5] batman-adv: limit numbers of parallel learned BLA backbones

On Tuesday, 19 May 2026 09:02:18 CEST Sven Eckelmann wrote:
> @@ -505,6 +507,11 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, const u8 *orig,
>                    "%s(): not found (%pM, %d), creating new entry\n", __func__,
>                    orig, batadv_print_vid(vid));
>  
> +       bla_backbone_max_learned = READ_ONCE(bat_priv->bla_backbone_max_learned);
> +       bla_backbone_learned = atomic_read(&bat_priv->bla_backbone_learned);
> +       if (bla_backbone_max_learned && bla_backbone_learned >= bla_backbone_max_learned)
> +               return NULL;
> +
>         entry = kzalloc_obj(*entry, GFP_ATOMIC);
>         if (!entry)
>                 return NULL;

@Simon: remark from Sashiko, should we actually exempt own_gateway?


@@ -508,10 +508,12 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, const u8 *orig,
 		   "%s(): not found (%pM, %d), creating new entry\n", __func__,
 		   orig, batadv_print_vid(vid));
 
-	bla_backbone_max_learned = READ_ONCE(bat_priv->bla_backbone_max_learned);
-	bla_backbone_learned = atomic_read(&bat_priv->bla_backbone_learned);
-	if (bla_backbone_max_learned && bla_backbone_learned >= bla_backbone_max_learned)
-		return NULL;
+	if (!own_backbone) {
+		bla_backbone_max_learned = READ_ONCE(bat_priv->bla_backbone_max_learned);
+		bla_backbone_learned = atomic_read(&bat_priv->bla_backbone_learned);
+		if (bla_backbone_max_learned && bla_backbone_learned >= bla_backbone_max_learned)
+			return NULL;
+	}
 
 	entry = kzalloc_obj(*entry, GFP_ATOMIC);
 	if (!entry)
@@ -539,7 +541,10 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, const u8 *orig,
 	if (unlikely(hash_added != 0)) {
 		/* hash failed, free the structure */
 		kfree(entry);
-		atomic_dec(&bat_priv->bla_backbone_learned);
+
+		if (!own_backbone)
+			atomic_dec(&bat_priv->bla_backbone_learned);
+
 		return NULL;
 	}
 
Regards,
	Sven

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