batman-adv: Use own timer for multicast TT and TVLV updates

Instead of latching onto the OGM period, this patch introduces a worker
dedicated to multicast TT and TVLV updates.

The reasoning is, that upon roaming especially the translation table
should be updated timely to minimize connectivity issues.

With BATMAN V, the idea is to greatly increase the OGM interval to
reduce overhead. Unfortunately, right now this could lead to
a bad user experience if multicast traffic is involved.

Therefore this patch introduces a fixed 500ms update interval for
multicast TT entries and the multicast TVLV.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index daddca94feb89f8c53248998dbc4379a01ef6891..a6cc8040a21dd24fb507683230fd66a9edb62458 100644 (file)
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -48,6 +48,7 @@
 #define BATADV_TT_CLIENT_TEMP_TIMEOUT 600000 /* in milliseconds */
 #define BATADV_TT_WORK_PERIOD 5000 /* 5 seconds */
 #define BATADV_ORIG_WORK_PERIOD 1000 /* 1 second */
+#define BATADV_MCAST_WORK_PERIOD 500 /* 0.5 seconds */
 #define BATADV_DAT_ENTRY_TIMEOUT (5 * 60000) /* 5 mins in milliseconds */
 /* sliding packet range of received originator messages in sequence numbers
  * (should be a multiple of our word size)

diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
index 45757faafbd7a40e6eff313085b4f829fcddbf25..090a69fc342eac8a0b6bf89556d2b32523817d09 100644 (file)
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -33,6 +33,7 @@
 #include <linux/in6.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
+#include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/kref.h>
 #include <linux/list.h>
@@ -48,6 +49,7 @@
 #include <linux/stddef.h>
 #include <linux/string.h>
 #include <linux/types.h>
+#include <linux/workqueue.h>
 #include <net/addrconf.h>
 #include <net/if_inet6.h>
 #include <net/ip.h>
@@ -60,6 +62,18 @@
 #include "translation-table.h"
 #include "tvlv.h"
 
+static void batadv_mcast_mla_update(struct work_struct *work);
+
+/**
+ * batadv_mcast_start_timer - schedule the multicast periodic worker
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_mcast_start_timer(struct batadv_priv *bat_priv)
+{
+       queue_delayed_work(batadv_event_workqueue, &bat_priv->mcast.work,
+                          msecs_to_jiffies(BATADV_MCAST_WORK_PERIOD));
+}
+
 /**
  * batadv_mcast_get_bridge - get the bridge on top of the softif if it exists
  * @soft_iface: netdev struct of the mesh interface
@@ -255,6 +269,8 @@ static void batadv_mcast_mla_list_free(struct hlist_head *mcast_list)
  * translation table except the ones listed in the given mcast_list.
  *
  * If mcast_list is NULL then all are retracted.
+ *
+ * Do not call outside of the mcast worker! (or cancel mcast worker first)
  */
 static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv,
                                        struct hlist_head *mcast_list)
@@ -262,7 +278,7 @@ static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv,
        struct batadv_hw_addr *mcast_entry;
        struct hlist_node *tmp;
 
-       lockdep_assert_held(&bat_priv->tt.commit_lock);
+       WARN_ON(delayed_work_pending(&bat_priv->mcast.work));
 
        hlist_for_each_entry_safe(mcast_entry, tmp, &bat_priv->mcast.mla_list,
                                  list) {
@@ -287,6 +303,8 @@ static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv,
  *
  * Adds multicast listener announcements from the given mcast_list to the
  * translation table if they have not been added yet.
+ *
+ * Do not call outside of the mcast worker! (or cancel mcast worker first)
  */
 static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv,
                                    struct hlist_head *mcast_list)
@@ -294,7 +312,7 @@ static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv,
        struct batadv_hw_addr *mcast_entry;
        struct hlist_node *tmp;
 
-       lockdep_assert_held(&bat_priv->tt.commit_lock);
+       WARN_ON(delayed_work_pending(&bat_priv->mcast.work));
 
        if (!mcast_list)
                return;
@@ -528,13 +546,18 @@ static bool batadv_mcast_mla_tvlv_update(struct batadv_priv *bat_priv)
 }
 
 /**
- * batadv_mcast_mla_update - update the own MLAs
+ * __batadv_mcast_mla_update - update the own MLAs
  * @bat_priv: the bat priv with all the soft interface information
  *
  * Updates the own multicast listener announcements in the translation
  * table as well as the own, announced multicast tvlv container.
+ *
+ * Note that non-conflicting reads and writes to bat_priv->mcast.mla_list
+ * in batadv_mcast_mla_tt_retract() and batadv_mcast_mla_tt_add() are
+ * ensured by the non-parallel execution of the worker this function
+ * belongs to.
  */
-void batadv_mcast_mla_update(struct batadv_priv *bat_priv)
+static void __batadv_mcast_mla_update(struct batadv_priv *bat_priv)
 {
        struct net_device *soft_iface = bat_priv->soft_iface;
        struct hlist_head mcast_list = HLIST_HEAD_INIT;
@@ -559,6 +582,29 @@ void batadv_mcast_mla_update(struct batadv_priv *bat_priv)
        batadv_mcast_mla_list_free(&mcast_list);
 }
 
+/**
+ * batadv_mcast_mla_update - update the own MLAs
+ * @work: kernel work struct
+ *
+ * Updates the own multicast listener announcements in the translation
+ * table as well as the own, announced multicast tvlv container.
+ *
+ * In the end, reschedules the work timer.
+ */
+static void batadv_mcast_mla_update(struct work_struct *work)
+{
+       struct delayed_work *delayed_work;
+       struct batadv_priv_mcast *priv_mcast;
+       struct batadv_priv *bat_priv;
+
+       delayed_work = to_delayed_work(work);
+       priv_mcast = container_of(delayed_work, struct batadv_priv_mcast, work);
+       bat_priv = container_of(priv_mcast, struct batadv_priv, mcast);
+
+       __batadv_mcast_mla_update(bat_priv);
+       batadv_mcast_start_timer(bat_priv);
+}
+
 /**
  * batadv_mcast_is_report_ipv4 - check for IGMP reports
  * @skb: the ethernet frame destined for the mesh
@@ -1128,6 +1174,9 @@ void batadv_mcast_init(struct batadv_priv *bat_priv)
        batadv_tvlv_handler_register(bat_priv, batadv_mcast_tvlv_ogm_handler,
                                     NULL, BATADV_TVLV_MCAST, 2,
                                     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
+
+       INIT_DELAYED_WORK(&bat_priv->mcast.work, batadv_mcast_mla_update);
+       batadv_mcast_start_timer(bat_priv);
 }
 
 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
@@ -1239,12 +1288,13 @@ int batadv_mcast_flags_seq_print_text(struct seq_file *seq, void *offset)
  */
 void batadv_mcast_free(struct batadv_priv *bat_priv)
 {
+       cancel_delayed_work_sync(&bat_priv->mcast.work);
+
        batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_MCAST, 2);
        batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST, 2);
 
-       spin_lock_bh(&bat_priv->tt.commit_lock);
+       /* safely calling outside of worker, as worker was canceled above */
        batadv_mcast_mla_tt_retract(bat_priv, NULL);
-       spin_unlock_bh(&bat_priv->tt.commit_lock);
 }
 
 /**

diff --git a/net/batman-adv/multicast.h b/net/batman-adv/multicast.h
index 1fb00ba84907a46732c33deac4aed01061222b1c..2cddaf52a21d5e8ea927c96e51e5a811de6785c9 100644 (file)
--- a/net/batman-adv/multicast.h
+++ b/net/batman-adv/multicast.h
@@ -39,8 +39,6 @@ enum batadv_forw_mode {
 
 #ifdef CONFIG_BATMAN_ADV_MCAST
 
-void batadv_mcast_mla_update(struct batadv_priv *bat_priv);
-
 enum batadv_forw_mode
 batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
                       struct batadv_orig_node **mcast_single_orig);
@@ -55,10 +53,6 @@ void batadv_mcast_purge_orig(struct batadv_orig_node *orig_node);
 
 #else
 
-static inline void batadv_mcast_mla_update(struct batadv_priv *bat_priv)
-{
-}
-
 static inline enum batadv_forw_mode
 batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
                       struct batadv_orig_node **mcast_single_orig)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index ad1e3bc0e205059b01fbeb2e5089371636a33197..3cae8f4fd7176963f85331bd45abfee26e0f953a 100644 (file)
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -56,7 +56,6 @@
 #include "hard-interface.h"
 #include "hash.h"
 #include "log.h"
-#include "multicast.h"
 #include "netlink.h"
 #include "originator.h"
 #include "packet.h"
@@ -3795,9 +3794,6 @@ static void batadv_tt_local_commit_changes_nolock(struct batadv_priv *bat_priv)
 {
        lockdep_assert_held(&bat_priv->tt.commit_lock);
 
-       /* Update multicast addresses in local translation table */
-       batadv_mcast_mla_update(bat_priv);
-
        if (atomic_read(&bat_priv->tt.local_changes) < 1) {
                if (!batadv_atomic_dec_not_zero(&bat_priv->tt.ogm_append_cnt))
                        batadv_tt_tvlv_container_update(bat_priv);

diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index c9db184bfef8929992e82e3dffe26c306cb92cfc..0d46aeac9fd91f5bdf5418ed66f19b7d2da6395d 100644 (file)
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -785,9 +785,10 @@ struct batadv_mcast_querier_state {
  * @num_want_all_ipv6: counter for items in want_all_ipv6_list
  * @want_lists_lock: lock for protecting modifications to mcast want lists
  *  (traversals are rcu-locked)
+ * @work: work queue callback item for multicast TT and TVLV updates
  */
 struct batadv_priv_mcast {
-       struct hlist_head mla_list;
+       struct hlist_head mla_list; /* see __batadv_mcast_mla_update() */
        struct hlist_head want_all_unsnoopables_list;
        struct hlist_head want_all_ipv4_list;
        struct hlist_head want_all_ipv6_list;
@@ -802,6 +803,7 @@ struct batadv_priv_mcast {
        atomic_t num_want_all_ipv6;
        /* protects want_all_{unsnoopables,ipv4,ipv6}_list */
        spinlock_t want_lists_lock;
+       struct delayed_work work;
 };
 #endif