On Thursday, 14 November 2024 14:58:43 CET Sven Eckelmann wrote:
Or maybe I missed something ?
net/batman-adv/soft-interface.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index b61f35918b5d..d7de54734725 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -599,7 +599,6 @@ batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
atomic_set(&vlan->ap_isolation, 0);
kref_get(&vlan->refcount);hlist_add_head_rcu(&vlan->list, &bat_priv->softif_vlan_list); spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
This ref is for the VLAN list entry (just one line below the kref_get). This patch is therefore definitely wrong.
Ok, had a look at the surrounding code from this patch and it looks too me like the reason for what a ref++ stands for was changed and so this initialization also needs to be changed. So, I have to correct my original statement about your patch, Nicholas. It is definitely an improvement to the refcnt (with this patch, not before). But at the same time, it should be made clear by Linus what the reference counter is used for. Especially because it was completely different before the patch and different then most other things in batman-adv.
Starting with not simply dropping the kref_get but with a small comment explaining that there is "no kref_get for list because only TT entries per VLAN and temporary references on stack are tracked. list entries will be removed automatically when refcount reaches zero".
Kind regards, Sven