3 files changed, 55 insertions, 46 deletions

diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c
index 6826e4f61060..dcde56057fe1 100644
--- a/drivers/net/bonding/bond_3ad.c
+++ b/drivers/net/bonding/bond_3ad.c
@@ -2130,13 +2130,7 @@ re_arm:
         read_unlock(&bond->lock);
 
         if (should_notify_rtnl && rtnl_trylock()) {
-                bond_for_each_slave(bond, slave, iter) {
-                        if (slave->should_notify) {
-                                rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0,
-                                             GFP_KERNEL);
-                                slave->should_notify = 0;
-                        }
-                }
+                bond_slave_state_notify(bond);
                 rtnl_unlock();
         }
         queue_delayed_work(bond->wq, &bond->ad_work, ad_delta_in_ticks);
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index e02029bbf5cc..82b70ff1fd28 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2623,17 +2623,17 @@ do_failover:
 
 /*
  * Send ARP probes for active-backup mode ARP monitor.
+ *
+ * Called with rcu_read_lock hold.
  */
 static bool bond_ab_arp_probe(struct bonding *bond)
 {
         struct slave *slave, *before = NULL, *new_slave = NULL,
-                     *curr_arp_slave, *curr_active_slave;
+                     *curr_arp_slave = rcu_dereference(bond->current_arp_slave),
+                     *curr_active_slave = rcu_dereference(bond->curr_active_slave);
         struct list_head *iter;
         bool found = false;
-
-        rcu_read_lock();
-        curr_arp_slave = rcu_dereference(bond->current_arp_slave);
-        curr_active_slave = rcu_dereference(bond->curr_active_slave);
+        bool should_notify_rtnl = BOND_SLAVE_NOTIFY_LATER;
 
         if (curr_arp_slave && curr_active_slave)
                 pr_info("PROBE: c_arp %s && cas %s BAD\n",
@@ -2642,32 +2642,23 @@ static bool bond_ab_arp_probe(struct bonding *bond)
 
         if (curr_active_slave) {
                 bond_arp_send_all(bond, curr_active_slave);
-                rcu_read_unlock();
-                return true;
+                return should_notify_rtnl;
         }
-        rcu_read_unlock();
 
         /* if we don't have a curr_active_slave, search for the next available
          * backup slave from the current_arp_slave and make it the candidate
          * for becoming the curr_active_slave
          */
 
-        if (!rtnl_trylock())
-                return false;
-        /* curr_arp_slave might have gone away */
-        curr_arp_slave = ACCESS_ONCE(bond->current_arp_slave);
-
         if (!curr_arp_slave) {
-                curr_arp_slave = bond_first_slave(bond);
-                if (!curr_arp_slave) {
-                        rtnl_unlock();
-                        return true;
-                }
+                curr_arp_slave = bond_first_slave_rcu(bond);
+                if (!curr_arp_slave)
+                        return should_notify_rtnl;
         }
 
-        bond_set_slave_inactive_flags(curr_arp_slave, BOND_SLAVE_NOTIFY_NOW);
+        bond_set_slave_inactive_flags(curr_arp_slave, BOND_SLAVE_NOTIFY_LATER);
 
-        bond_for_each_slave(bond, slave, iter) {
+        bond_for_each_slave_rcu(bond, slave, iter) {
                 if (!found && !before && IS_UP(slave->dev))
                         before = slave;
 
@@ -2686,7 +2677,7 @@ static bool bond_ab_arp_probe(struct bonding *bond)
                                 slave->link_failure_count++;
 
                         bond_set_slave_inactive_flags(slave,
-                                                      BOND_SLAVE_NOTIFY_NOW);
+                                                      BOND_SLAVE_NOTIFY_LATER);
 
                         pr_info("%s: backup interface %s is now down.\n",
                                 bond->dev->name, slave->dev->name);
@@ -2698,26 +2689,31 @@ static bool bond_ab_arp_probe(struct bonding *bond)
         if (!new_slave && before)
                 new_slave = before;
 
-        if (!new_slave) {
-                rtnl_unlock();
-                return true;
-        }
+        if (!new_slave)
+                goto check_state;
 
         new_slave->link = BOND_LINK_BACK;
-        bond_set_slave_active_flags(new_slave, BOND_SLAVE_NOTIFY_NOW);
+        bond_set_slave_active_flags(new_slave, BOND_SLAVE_NOTIFY_LATER);
         bond_arp_send_all(bond, new_slave);
         new_slave->jiffies = jiffies;
         rcu_assign_pointer(bond->current_arp_slave, new_slave);
-        rtnl_unlock();
 
-        return true;
+check_state:
+        bond_for_each_slave_rcu(bond, slave, iter) {
+                if (slave->should_notify) {
+                        should_notify_rtnl = BOND_SLAVE_NOTIFY_NOW;
+                        break;
+                }
+        }
+        return should_notify_rtnl;
 }
 
 static void bond_activebackup_arp_mon(struct work_struct *work)
 {
         struct bonding *bond = container_of(work, struct bonding,
                                             arp_work.work);
-        bool should_notify_peers = false, should_commit = false;
+        bool should_notify_peers = false;
+        bool should_notify_rtnl = false;
         int delta_in_ticks;
 
         delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);
@@ -2726,11 +2722,12 @@ static void bond_activebackup_arp_mon(struct work_struct *work)
                 goto re_arm;
 
         rcu_read_lock();
+
         should_notify_peers = bond_should_notify_peers(bond);
-        should_commit = bond_ab_arp_inspect(bond);
-        rcu_read_unlock();
 
-        if (should_commit) {
+        if (bond_ab_arp_inspect(bond)) {
+                rcu_read_unlock();
+
                 /* Race avoidance with bond_close flush of workqueue */
                 if (!rtnl_trylock()) {
                         delta_in_ticks = 1;
@@ -2739,23 +2736,28 @@ static void bond_activebackup_arp_mon(struct work_struct *work)
                 }
 
                 bond_ab_arp_commit(bond);
+
                 rtnl_unlock();
+                rcu_read_lock();
         }
 
-        if (!bond_ab_arp_probe(bond)) {
-                /* rtnl locking failed, re-arm */
-                delta_in_ticks = 1;
-                should_notify_peers = false;
-        }
+        should_notify_rtnl = bond_ab_arp_probe(bond);
+        rcu_read_unlock();
 
 re_arm:
         if (bond->params.arp_interval)
                 queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks);
 
-        if (should_notify_peers) {
+        if (should_notify_peers || should_notify_rtnl) {
                 if (!rtnl_trylock())
                         return;
-                call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev);
+
+                if (should_notify_peers)
+                        call_netdevice_notifiers(NETDEV_NOTIFY_PEERS,
+                                                 bond->dev);
+                if (should_notify_rtnl)
+                        bond_slave_state_notify(bond);
+
                 rtnl_unlock();
         }
 }
diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 9b280ac8c454..2b0fdec695f7 100644
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -335,6 +335,19 @@ static inline void bond_slave_state_change(struct bonding *bond)
         }
 }
 
+static inline void bond_slave_state_notify(struct bonding *bond)
+{
+        struct list_head *iter;
+        struct slave *tmp;
+
+        bond_for_each_slave(bond, tmp, iter) {
+                if (tmp->should_notify) {
+                        rtmsg_ifinfo(RTM_NEWLINK, tmp->dev, 0, GFP_KERNEL);
+                        tmp->should_notify = 0;
+                }
+        }
+}
+
 static inline int bond_slave_state(struct slave *slave)
 {
         return slave->backup;