Hey Antonio,
On Thu, Jan 10, 2013 at 04:34:47AM +0200, Antonio Quartulli wrote:
Hello Simon,
thanks a lot for taking care of this and sorry for my very late reply..
no problem, thanks for your review!
Il 31.12.2012 01:40 Simon Wunderlich ha scritto:
diff --git a/hard-interface.c b/hard-interface.c index f1d37cd..eb3a12d 100644 --- a/hard-interface.c +++ b/hard-interface.c @@ -506,6 +506,17 @@ out: return NULL; }
+static void batadv_hardif_remove_interface_finish(struct work_struct *work) +{
- struct batadv_hard_iface *hard_iface;
- hard_iface = container_of(work, struct batadv_hard_iface,
cleanup_work);- batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
- batadv_hardif_free_ref(hard_iface);
+}
static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface) { ASSERT_RTNL(); @@ -518,8 +529,9 @@ static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface) return;
hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
- batadv_sysfs_del_hardif(&hard_iface->hardif_obj);
- batadv_hardif_free_ref(hard_iface);
- INIT_WORK(&hard_iface->cleanup_work,
batadv_hardif_remove_interface_finish);- queue_work(batadv_event_workqueue, &hard_iface->cleanup_work);
}
why do we need to postpone the invocation of batadv_hardif_remove_interface_finish() ? Is it also creating a possible deadlock? As far as I understood only rtnl_lock() would create the problem, but it is not invoked in batadv_hardif_remove_interface_finish(). It seems I am missing something?
batadv_hardif_remove_interface() is called by batadv_hard_if_event(), which is protected rtnl_lock(). You can find an ASSERT_RTNL() there too. As batadv_hardif_remove_interface() then removes sysfs, this could be problematic.
Other than this, remember that the INIT_WORK macro does not need to be invoked each and every time you want to enqueue the work. It should be invoked once only (A patch fixing this "issue" for all the delayed works we have in the code has been recently applied). However it is not a real issue, but we want to keep the code consistent :)
Well, the work item is actually only initialized once, before taking the interface down. Then the struct is destroyed, so it can't be called again. But you are right, for consistency I will move the INIT_WORK macros to positions where the structs are initialized.
int batadv_softif_is_valid(const struct net_device *net_dev) diff --git a/types.h b/types.h index d8061ac..a9800ee 100644 --- a/types.h +++ b/types.h @@ -63,6 +63,7 @@ struct batadv_hard_iface { struct net_device *soft_iface; struct rcu_head rcu; struct batadv_hard_iface_bat_iv bat_iv;
- struct work_struct cleanup_work;
};
kernel doc :)
The Mareks kernel doc patch wasn't applied at this time, so I didn't bother documenting my single new variable, but will do that in the next revision. :)
Thanks, Simon