bonding: eliminate bond_close race conditions

[kernel/kernel-generic.git] / drivers / net / bonding / bond_main.c

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index c5944f1..c34cc1e 100644 (file)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -773,9 +773,6 @@ static void bond_resend_igmp_join_requests(struct bonding *bond)
 
        read_lock(&bond->lock);
 
-       if (bond->kill_timers)
-               goto out;
-
        /* rejoin all groups on bond device */
        __bond_resend_igmp_join_requests(bond->dev);
 
@@ -789,9 +786,9 @@ static void bond_resend_igmp_join_requests(struct bonding *bond)
                        __bond_resend_igmp_join_requests(vlan_dev);
        }
 
-       if ((--bond->igmp_retrans > 0) && !bond->kill_timers)
+       if (--bond->igmp_retrans > 0)
                queue_delayed_work(bond->wq, &bond->mcast_work, HZ/5);
-out:
+
        read_unlock(&bond->lock);
 }
 
@@ -2517,10 +2514,11 @@ void bond_mii_monitor(struct work_struct *work)
        struct bonding *bond = container_of(work, struct bonding,
                                            mii_work.work);
        bool should_notify_peers = false;
+       unsigned long delay;
 
        read_lock(&bond->lock);
-       if (bond->kill_timers)
-               goto out;
+
+       delay = msecs_to_jiffies(bond->params.miimon);
 
        if (bond->slave_cnt == 0)
                goto re_arm;
@@ -2529,7 +2527,15 @@ void bond_mii_monitor(struct work_struct *work)
 
        if (bond_miimon_inspect(bond)) {
                read_unlock(&bond->lock);
-               rtnl_lock();
+
+               /* Race avoidance with bond_close cancel of workqueue */
+               if (!rtnl_trylock()) {
+                       read_lock(&bond->lock);
+                       delay = 1;
+                       should_notify_peers = false;
+                       goto re_arm;
+               }
+
                read_lock(&bond->lock);
 
                bond_miimon_commit(bond);
@@ -2540,14 +2546,18 @@ void bond_mii_monitor(struct work_struct *work)
        }
 
 re_arm:
-       if (bond->params.miimon && !bond->kill_timers)
-               queue_delayed_work(bond->wq, &bond->mii_work,
-                                  msecs_to_jiffies(bond->params.miimon));
-out:
+       if (bond->params.miimon)
+               queue_delayed_work(bond->wq, &bond->mii_work, delay);
+
        read_unlock(&bond->lock);
 
        if (should_notify_peers) {
-               rtnl_lock();
+               if (!rtnl_trylock()) {
+                       read_lock(&bond->lock);
+                       bond->send_peer_notif++;
+                       read_unlock(&bond->lock);
+                       return;
+               }
                netdev_bonding_change(bond->dev, NETDEV_NOTIFY_PEERS);
                rtnl_unlock();
        }
@@ -2789,9 +2799,6 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
 
        delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);
 
-       if (bond->kill_timers)
-               goto out;
-
        if (bond->slave_cnt == 0)
                goto re_arm;
 
@@ -2888,9 +2895,9 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
        }
 
 re_arm:
-       if (bond->params.arp_interval && !bond->kill_timers)
+       if (bond->params.arp_interval)
                queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks);
-out:
+
        read_unlock(&bond->lock);
 }
 
@@ -3131,9 +3138,6 @@ void bond_activebackup_arp_mon(struct work_struct *work)
 
        read_lock(&bond->lock);
 
-       if (bond->kill_timers)
-               goto out;
-
        delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);
 
        if (bond->slave_cnt == 0)
@@ -3143,7 +3147,15 @@ void bond_activebackup_arp_mon(struct work_struct *work)
 
        if (bond_ab_arp_inspect(bond, delta_in_ticks)) {
                read_unlock(&bond->lock);
-               rtnl_lock();
+
+               /* Race avoidance with bond_close flush of workqueue */
+               if (!rtnl_trylock()) {
+                       read_lock(&bond->lock);
+                       delta_in_ticks = 1;
+                       should_notify_peers = false;
+                       goto re_arm;
+               }
+
                read_lock(&bond->lock);
 
                bond_ab_arp_commit(bond, delta_in_ticks);
@@ -3156,13 +3168,18 @@ void bond_activebackup_arp_mon(struct work_struct *work)
        bond_ab_arp_probe(bond);
 
 re_arm:
-       if (bond->params.arp_interval && !bond->kill_timers)
+       if (bond->params.arp_interval)
                queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks);
-out:
+
        read_unlock(&bond->lock);
 
        if (should_notify_peers) {
-               rtnl_lock();
+               if (!rtnl_trylock()) {
+                       read_lock(&bond->lock);
+                       bond->send_peer_notif++;
+                       read_unlock(&bond->lock);
+                       return;
+               }
                netdev_bonding_change(bond->dev, NETDEV_NOTIFY_PEERS);
                rtnl_unlock();
        }
@@ -3424,8 +3441,6 @@ static int bond_open(struct net_device *bond_dev)
        struct slave *slave;
        int i;
 
-       bond->kill_timers = 0;
-
        /* reset slave->backup and slave->inactive */
        read_lock(&bond->lock);
        if (bond->slave_cnt > 0) {
@@ -3494,33 +3509,30 @@ static int bond_close(struct net_device *bond_dev)
 
        bond->send_peer_notif = 0;
 
-       /* signal timers not to re-arm */
-       bond->kill_timers = 1;
-
        write_unlock_bh(&bond->lock);
 
        if (bond->params.miimon) {  /* link check interval, in milliseconds. */
-               cancel_delayed_work(&bond->mii_work);
+               cancel_delayed_work_sync(&bond->mii_work);
        }
 
        if (bond->params.arp_interval) {  /* arp interval, in milliseconds. */
-               cancel_delayed_work(&bond->arp_work);
+               cancel_delayed_work_sync(&bond->arp_work);
        }
 
        switch (bond->params.mode) {
        case BOND_MODE_8023AD:
-               cancel_delayed_work(&bond->ad_work);
+               cancel_delayed_work_sync(&bond->ad_work);
                break;
        case BOND_MODE_TLB:
        case BOND_MODE_ALB:
-               cancel_delayed_work(&bond->alb_work);
+               cancel_delayed_work_sync(&bond->alb_work);
                break;
        default:
                break;
        }
 
        if (delayed_work_pending(&bond->mcast_work))
-               cancel_delayed_work(&bond->mcast_work);
+               cancel_delayed_work_sync(&bond->mcast_work);
 
        if (bond_is_lb(bond)) {
                /* Must be called only after all
@@ -4367,26 +4379,22 @@ static void bond_setup(struct net_device *bond_dev)
 
 static void bond_work_cancel_all(struct bonding *bond)
 {
-       write_lock_bh(&bond->lock);
-       bond->kill_timers = 1;
-       write_unlock_bh(&bond->lock);
-
        if (bond->params.miimon && delayed_work_pending(&bond->mii_work))
-               cancel_delayed_work(&bond->mii_work);
+               cancel_delayed_work_sync(&bond->mii_work);
 
        if (bond->params.arp_interval && delayed_work_pending(&bond->arp_work))
-               cancel_delayed_work(&bond->arp_work);
+               cancel_delayed_work_sync(&bond->arp_work);
 
        if (bond->params.mode == BOND_MODE_ALB &&
            delayed_work_pending(&bond->alb_work))
-               cancel_delayed_work(&bond->alb_work);
+               cancel_delayed_work_sync(&bond->alb_work);
 
        if (bond->params.mode == BOND_MODE_8023AD &&
            delayed_work_pending(&bond->ad_work))
-               cancel_delayed_work(&bond->ad_work);
+               cancel_delayed_work_sync(&bond->ad_work);
 
        if (delayed_work_pending(&bond->mcast_work))
-               cancel_delayed_work(&bond->mcast_work);
+               cancel_delayed_work_sync(&bond->mcast_work);
 }
 
 /*