[BRIDGE]: eliminate workqueue for carrier check

Having a work queue for checking carrier leads to lots of race issues.
Simpler to just get the cost when data structure is created and
update on change.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 17 insertions, 42 deletions

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index aff6a779c9c8..6845a258408f 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -77,26 +77,15 @@ static int port_cost(struct net_device *dev)
  * Called from work queue to allow for calling functions that
  * might sleep (such as speed check), and to debounce.
  */
-static void port_carrier_check(struct work_struct *work)
+void br_port_carrier_check(struct net_bridge_port *p)
 {
-        struct net_bridge_port *p;
-        struct net_device *dev;
-        struct net_bridge *br;
-
-        dev = container_of(work, struct net_bridge_port,
-                           carrier_check.work)->dev;
-        work_release(work);
-
-        rtnl_lock();
-        p = dev->br_port;
-        if (!p)
-                goto done;
-        br = p->br;
+        struct net_device *dev = p->dev;
+        struct net_bridge *br = p->br;
 
         if (netif_carrier_ok(dev))
                 p->path_cost = port_cost(dev);
 
-        if (br->dev->flags & IFF_UP) {
+        if (netif_running(br->dev)) {
                 spin_lock_bh(&br->lock);
                 if (netif_carrier_ok(dev)) {
                         if (p->state == BR_STATE_DISABLED)
@@ -107,9 +96,6 @@ static void port_carrier_check(struct work_struct *work)
                 }
                 spin_unlock_bh(&br->lock);
         }
-done:
-        dev_put(dev);
-        rtnl_unlock();
 }
 
 static void release_nbp(struct kobject *kobj)
@@ -162,9 +148,6 @@ static void del_nbp(struct net_bridge_port *p)
 
         dev_set_promiscuity(dev, -1);
 
-        if (cancel_delayed_work(&p->carrier_check))
-                dev_put(dev);
-
         spin_lock_bh(&br->lock);
         br_stp_disable_port(p);
         spin_unlock_bh(&br->lock);
@@ -282,7 +265,6 @@ static struct net_bridge_port *new_nbp(struct net_bridge *br,
         p->port_no = index;
         br_init_port(p);
         p->state = BR_STATE_DISABLED;
-        INIT_DELAYED_WORK_NAR(&p->carrier_check, port_carrier_check);
         br_stp_port_timer_init(p);
 
         kobject_init(&p->kobj);
@@ -446,12 +428,10 @@ int br_add_if(struct net_bridge *br, struct net_device *dev)
         spin_lock_bh(&br->lock);
         br_stp_recalculate_bridge_id(br);
         br_features_recompute(br);
-        if (schedule_delayed_work(&p->carrier_check, BR_PORT_DEBOUNCE))
-                dev_hold(dev);
-
         spin_unlock_bh(&br->lock);
 
         dev_set_mtu(br->dev, br_min_mtu(br));
+
         kobject_uevent(&p->kobj, KOBJ_ADD);
 
         return 0;
diff --git a/net/bridge/br_notify.c b/net/bridge/br_notify.c
index 3311c4e30829..37357ed2149b 100644
--- a/net/bridge/br_notify.c
+++ b/net/bridge/br_notify.c
@@ -42,51 +42,48 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v
 
         br = p->br;
 
-        spin_lock_bh(&br->lock);
         switch (event) {
         case NETDEV_CHANGEMTU:
                 dev_set_mtu(br->dev, br_min_mtu(br));
                 break;
 
         case NETDEV_CHANGEADDR:
+                spin_lock_bh(&br->lock);
                 br_fdb_changeaddr(p, dev->dev_addr);
                 br_ifinfo_notify(RTM_NEWLINK, p);
                 br_stp_recalculate_bridge_id(br);
+                spin_unlock_bh(&br->lock);
                 break;
 
         case NETDEV_CHANGE:
-                if (br->dev->flags & IFF_UP)
-                        if (schedule_delayed_work(&p->carrier_check,
-                                                BR_PORT_DEBOUNCE))
-                                dev_hold(dev);
+                br_port_carrier_check(p);
                 break;
 
         case NETDEV_FEAT_CHANGE:
-                if (br->dev->flags & IFF_UP)
+                spin_lock_bh(&br->lock);
+                if (netif_running(br->dev))
                         br_features_recompute(br);
-
-                /* could do recursive feature change notification
-                 * but who would care??
-                 */
+                spin_unlock_bh(&br->lock);
                 break;
 
         case NETDEV_DOWN:
+                spin_lock_bh(&br->lock);
                 if (br->dev->flags & IFF_UP)
                         br_stp_disable_port(p);
+                spin_unlock_bh(&br->lock);
                 break;
 
         case NETDEV_UP:
+                spin_lock_bh(&br->lock);
                 if (netif_carrier_ok(dev) && (br->dev->flags & IFF_UP))
                         br_stp_enable_port(p);
+                spin_unlock_bh(&br->lock);
                 break;
 
         case NETDEV_UNREGISTER:
-                spin_unlock_bh(&br->lock);
                 br_del_if(br, dev);
-                goto done;
+                break;
         }
-        spin_unlock_bh(&br->lock);
 
- done:
         return NOTIFY_DONE;
 }
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 16fc47a821e5..cc3f1c99261a 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -26,8 +26,6 @@
 #define BR_PORT_BITS    10
 #define BR_MAX_PORTS    (1<<BR_PORT_BITS)
 
-#define BR_PORT_DEBOUNCE (HZ/10)
-
 #define BR_VERSION      "2.2"
 
 typedef struct bridge_id bridge_id;
@@ -81,7 +79,6 @@ struct net_bridge_port
         struct timer_list               hold_timer;
         struct timer_list               message_age_timer;
         struct kobject                  kobj;
-        struct delayed_work             carrier_check;
         struct rcu_head                 rcu;
 };
 
@@ -172,6 +169,7 @@ extern void br_flood_forward(struct net_bridge *br,
                       int clone);
 
 /* br_if.c */
+extern void br_port_carrier_check(struct net_bridge_port *p);
 extern int br_add_bridge(const char *name);
 extern int br_del_bridge(const char *name);
 extern void br_cleanup_bridges(void);