Merge branch 'drop-time' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek...

[~andy/linux] / drivers / net / bonding / bond_main.c

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index a7db819bca9278356598152060c4684bd6f615c7..4c08018d7333138a95d0d6a3c72c67131f842ed5 100644 (file)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2346,7 +2346,7 @@ static void bond_loadbalance_arp_mon(struct work_struct *work)
                                            arp_work.work);
        struct slave *slave, *oldcurrent;
        struct list_head *iter;
-       int do_failover = 0;
+       int do_failover = 0, slave_state_changed = 0;
 
        if (!bond_has_slaves(bond))
                goto re_arm;
@@ -2370,7 +2370,7 @@ static void bond_loadbalance_arp_mon(struct work_struct *work)
                            bond_time_in_interval(bond, slave->dev->last_rx, 1)) {
 
                                slave->link  = BOND_LINK_UP;
-                               bond_set_active_slave(slave);
+                               slave_state_changed = 1;
 
                                /* primary_slave has no meaning in round-robin
                                 * mode. the window of a slave being up and
@@ -2399,7 +2399,7 @@ static void bond_loadbalance_arp_mon(struct work_struct *work)
                            !bond_time_in_interval(bond, slave->dev->last_rx, 2)) {
 
                                slave->link  = BOND_LINK_DOWN;
-                               bond_set_backup_slave(slave);
+                               slave_state_changed = 1;
 
                                if (slave->link_failure_count < UINT_MAX)
                                        slave->link_failure_count++;
@@ -2426,19 +2426,24 @@ static void bond_loadbalance_arp_mon(struct work_struct *work)
 
        rcu_read_unlock();
 
-       if (do_failover) {
-               /* the bond_select_active_slave must hold RTNL
-                * and curr_slave_lock for write.
-                */
+       if (do_failover || slave_state_changed) {
                if (!rtnl_trylock())
                        goto re_arm;
-               block_netpoll_tx();
-               write_lock_bh(&bond->curr_slave_lock);
 
-               bond_select_active_slave(bond);
+               if (slave_state_changed) {
+                       bond_slave_state_change(bond);
+               } else if (do_failover) {
+                       /* the bond_select_active_slave must hold RTNL
+                        * and curr_slave_lock for write.
+                        */
+                       block_netpoll_tx();
+                       write_lock_bh(&bond->curr_slave_lock);
 
-               write_unlock_bh(&bond->curr_slave_lock);
-               unblock_netpoll_tx();
+                       bond_select_active_slave(bond);
+
+                       write_unlock_bh(&bond->curr_slave_lock);
+                       unblock_netpoll_tx();
+               }
                rtnl_unlock();
        }
 
@@ -2599,45 +2604,51 @@ do_failover:
 
 /*
  * Send ARP probes for active-backup mode ARP monitor.
- *
- * Called with rcu_read_lock hold.
  */
-static void bond_ab_arp_probe(struct bonding *bond)
+static bool bond_ab_arp_probe(struct bonding *bond)
 {
        struct slave *slave, *before = NULL, *new_slave = NULL,
-                    *curr_arp_slave = rcu_dereference(bond->current_arp_slave);
+                    *curr_arp_slave, *curr_active_slave;
        struct list_head *iter;
        bool found = false;
 
-       read_lock(&bond->curr_slave_lock);
+       rcu_read_lock();
+       curr_arp_slave = rcu_dereference(bond->current_arp_slave);
+       curr_active_slave = rcu_dereference(bond->curr_active_slave);
 
-       if (curr_arp_slave && bond->curr_active_slave)
+       if (curr_arp_slave && curr_active_slave)
                pr_info("PROBE: c_arp %s && cas %s BAD\n",
                        curr_arp_slave->dev->name,
-                       bond->curr_active_slave->dev->name);
+                       curr_active_slave->dev->name);
 
-       if (bond->curr_active_slave) {
-               bond_arp_send_all(bond, bond->curr_active_slave);
-               read_unlock(&bond->curr_slave_lock);
-               return;
+       if (curr_active_slave) {
+               bond_arp_send_all(bond, curr_active_slave);
+               rcu_read_unlock();
+               return true;
        }
-
-       read_unlock(&bond->curr_slave_lock);
+       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_rcu(bond);
-               if (!curr_arp_slave)
-                       return;
+               curr_arp_slave = bond_first_slave(bond);
+               if (!curr_arp_slave) {
+                       rtnl_unlock();
+                       return true;
+               }
        }
 
        bond_set_slave_inactive_flags(curr_arp_slave);
 
-       bond_for_each_slave_rcu(bond, slave, iter) {
+       bond_for_each_slave(bond, slave, iter) {
                if (!found && !before && IS_UP(slave->dev))
                        before = slave;
 
@@ -2667,21 +2678,26 @@ static void bond_ab_arp_probe(struct bonding *bond)
        if (!new_slave && before)
                new_slave = before;
 
-       if (!new_slave)
-               return;
+       if (!new_slave) {
+               rtnl_unlock();
+               return true;
+       }
 
        new_slave->link = BOND_LINK_BACK;
        bond_set_slave_active_flags(new_slave);
        bond_arp_send_all(bond, new_slave);
        new_slave->jiffies = jiffies;
        rcu_assign_pointer(bond->current_arp_slave, new_slave);
+       rtnl_unlock();
+
+       return true;
 }
 
 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;
+       bool should_notify_peers = false, should_commit = false;
        int delta_in_ticks;
 
        delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);
@@ -2690,12 +2706,11 @@ 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 (bond_ab_arp_inspect(bond)) {
-               rcu_read_unlock();
-
+       if (should_commit) {
                /* Race avoidance with bond_close flush of workqueue */
                if (!rtnl_trylock()) {
                        delta_in_ticks = 1;
@@ -2704,13 +2719,14 @@ static void bond_activebackup_arp_mon(struct work_struct *work)
                }
 
                bond_ab_arp_commit(bond);
-
                rtnl_unlock();
-               rcu_read_lock();
        }
 
-       bond_ab_arp_probe(bond);
-       rcu_read_unlock();
+       if (!bond_ab_arp_probe(bond)) {
+               /* rtnl locking failed, re-arm */
+               delta_in_ticks = 1;
+               should_notify_peers = false;
+       }
 
 re_arm:
        if (bond->params.arp_interval)