[B.A.T.M.A.N.] [PATCH] batman-adv: prepare and schedule initial OGM without rtnl_lock()

[B.A.T.M.A.N.] [PATCH] batman-adv: prepare and schedule initial OGM without rtnl_lock()

[Linus Lüssing]

There is no need to hold the rtnl-lock during the preparation of the
initial OGM of a hard interface.

Besides, it is a little uggly to have batadv_schedule_bat_ogm() executed
with an rtnl-lock on its first run but without an rtnl-lock in its
rearmed versions as it makes additions to batadv_schedule_bat_ogm() that
require an rtnl-lock difficult.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
---

the compat code for the multicast-basic patchset needs an rtnl-lock
somewhere within batadv_schedule_bat_ogm()


 hard-interface.c |   21 ++++++++++++++++++++-
 types.h          |    2 ++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/hard-interface.c b/hard-interface.c
index c5f871f..c7ad8ae 100644
--- a/hard-interface.c
+++ b/hard-interface.c
@@ -470,7 +470,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
 			   hard_iface->net_dev->name);
 
 	/* begin scheduling originator messages on that interface */
-	batadv_schedule_bat_ogm(hard_iface);
+	queue_work(batadv_event_workqueue, &hard_iface->init_ogm_work);
 
 out:
 	return 0;
@@ -554,6 +554,23 @@ static void batadv_hardif_remove_interface_finish(struct work_struct *work)
 	batadv_hardif_free_ref(hard_iface);
 }
 
+/**
+ * batadv_hardif_init_ogm - initialize the ogm scheduler
+ * @work: work queue item
+ *
+ * Prepare and queue the initial OGM on this hard interface to get its ogm
+ * scheduler into gear.
+ */
+static void batadv_hardif_init_ogm(struct work_struct *work)
+{
+	struct batadv_hard_iface *hard_iface;
+
+	hard_iface = container_of(work, struct batadv_hard_iface,
+				  init_ogm_work);
+
+	batadv_schedule_bat_ogm(hard_iface);
+}
+
 static struct batadv_hard_iface *
 batadv_hardif_add_interface(struct net_device *net_dev)
 {
@@ -583,6 +600,8 @@ batadv_hardif_add_interface(struct net_device *net_dev)
 	INIT_LIST_HEAD(&hard_iface->list);
 	INIT_WORK(&hard_iface->cleanup_work,
 		  batadv_hardif_remove_interface_finish);
+	INIT_WORK(&hard_iface->init_ogm_work,
+		  batadv_hardif_init_ogm);
 
 	hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
 	if (batadv_is_wifi_netdev(net_dev))
diff --git a/types.h b/types.h
index 0d5b24b..a8b5725 100644
--- a/types.h
+++ b/types.h
@@ -62,6 +62,7 @@ struct batadv_hard_iface_bat_iv {
  * @rcu: struct used for freeing in an RCU-safe manner
  * @bat_iv: BATMAN IV specific per hard interface data
  * @cleanup_work: work queue callback item for hard interface deinit
+ * @init_ogm_work: work queue callback item for ogm scheduler initialization
  */
 struct batadv_hard_iface {
 	struct list_head list;
@@ -76,6 +77,7 @@ struct batadv_hard_iface {
 	struct rcu_head rcu;
 	struct batadv_hard_iface_bat_iv bat_iv;
 	struct work_struct cleanup_work;
+	struct work_struct init_ogm_work;
 };
 
 /**
-- 
1.7.10.4

Re: [B.A.T.M.A.N.] [PATCH] batman-adv: prepare and schedule initial OGM without rtnl_lock()

[Linus Lüssing]

Ok, please ignore this patch for now. I'm going to do it
differently with the multicast patches which won't need an
rtnl-lock.

Cheers, Linus

On Mon, Jul 15, 2013 at 03:46:14AM +0200, Linus Lüssing wrote:
> There is no need to hold the rtnl-lock during the preparation of the
> initial OGM of a hard interface.
> 
> Besides, it is a little uggly to have batadv_schedule_bat_ogm() executed
> with an rtnl-lock on its first run but without an rtnl-lock in its
> rearmed versions as it makes additions to batadv_schedule_bat_ogm() that
> require an rtnl-lock difficult.
> 
> Signed-off-by: Linus Lüssing <linus.luessing@web.de>
> ---
> 
> the compat code for the multicast-basic patchset needs an rtnl-lock
> somewhere within batadv_schedule_bat_ogm()
> 
> 
>  hard-interface.c |   21 ++++++++++++++++++++-
>  types.h          |    2 ++
>  2 files changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/hard-interface.c b/hard-interface.c
> index c5f871f..c7ad8ae 100644
> --- a/hard-interface.c
> +++ b/hard-interface.c
> @@ -470,7 +470,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
>  			   hard_iface->net_dev->name);
>  
>  	/* begin scheduling originator messages on that interface */
> -	batadv_schedule_bat_ogm(hard_iface);
> +	queue_work(batadv_event_workqueue, &hard_iface->init_ogm_work);
>  
>  out:
>  	return 0;
> @@ -554,6 +554,23 @@ static void batadv_hardif_remove_interface_finish(struct work_struct *work)
>  	batadv_hardif_free_ref(hard_iface);
>  }
>  
> +/**
> + * batadv_hardif_init_ogm - initialize the ogm scheduler
> + * @work: work queue item
> + *
> + * Prepare and queue the initial OGM on this hard interface to get its ogm
> + * scheduler into gear.
> + */
> +static void batadv_hardif_init_ogm(struct work_struct *work)
> +{
> +	struct batadv_hard_iface *hard_iface;
> +
> +	hard_iface = container_of(work, struct batadv_hard_iface,
> +				  init_ogm_work);
> +
> +	batadv_schedule_bat_ogm(hard_iface);
> +}
> +
>  static struct batadv_hard_iface *
>  batadv_hardif_add_interface(struct net_device *net_dev)
>  {
> @@ -583,6 +600,8 @@ batadv_hardif_add_interface(struct net_device *net_dev)
>  	INIT_LIST_HEAD(&hard_iface->list);
>  	INIT_WORK(&hard_iface->cleanup_work,
>  		  batadv_hardif_remove_interface_finish);
> +	INIT_WORK(&hard_iface->init_ogm_work,
> +		  batadv_hardif_init_ogm);
>  
>  	hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
>  	if (batadv_is_wifi_netdev(net_dev))
> diff --git a/types.h b/types.h
> index 0d5b24b..a8b5725 100644
> --- a/types.h
> +++ b/types.h
> @@ -62,6 +62,7 @@ struct batadv_hard_iface_bat_iv {
>   * @rcu: struct used for freeing in an RCU-safe manner
>   * @bat_iv: BATMAN IV specific per hard interface data
>   * @cleanup_work: work queue callback item for hard interface deinit
> + * @init_ogm_work: work queue callback item for ogm scheduler initialization
>   */
>  struct batadv_hard_iface {
>  	struct list_head list;
> @@ -76,6 +77,7 @@ struct batadv_hard_iface {
>  	struct rcu_head rcu;
>  	struct batadv_hard_iface_bat_iv bat_iv;
>  	struct work_struct cleanup_work;
> +	struct work_struct init_ogm_work;
>  };
>  
>  /**
> -- 
> 1.7.10.4
>