batman-adv: fix TT VLAN inconsistency on VLAN re-add
When a VLAN interface (on top of batX) is removed and
re-added within a short timeframe TT does not have enough
time to properly cleanup. This creates an internal TT state
mismatch as the newly created softif_vlan will be
initialized from scratch with a TT client count of zero
(even if TT entries for this VLAN still exist). The
resulting TT messages are bogus due to the counter / tt
client listing mismatch, thus creating inconsistencies on
every node in the network
To fix this issue destroy_vlan() has to not free the VLAN
object immediately but it has to be kept alive until all the
TT entries for this VLAN have been removed. destroy_vlan()
still removes the sysfs folder so that the user has the
feeling that everything went fine.
If the same VLAN is re-added before the old object is free'd,
then the latter is resurrected and re-used.
Implement such behaviour by increasing the reference counter
of a softif_vlan object every time a new local TT entry for
such VLAN is created and remove the object from the list
only when all the TT entries have been destroyed.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 34891a5..8854c05 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -687,6 +687,7 @@
/**
* struct batadv_softif_vlan - per VLAN attributes set
+ * @bat_priv: pointer to the mesh object
* @vid: VLAN identifier
* @kobj: kobject for sysfs vlan subdirectory
* @ap_isolation: AP isolation state
@@ -696,6 +697,7 @@
* @rcu: struct used for freeing in a RCU-safe manner
*/
struct batadv_softif_vlan {
+ struct batadv_priv *bat_priv;
unsigned short vid;
struct kobject *kobj;
atomic_t ap_isolation; /* boolean */