bonding: fix locking in bond_loadbalance_arp_mon()

The commit 1d3ee88ae0d605629bf369
(bonding: add netlink attributes to slave link dev)
has add rtmsg_ifinfo() in bond_set_active_slave() and
bond_set_backup_slave(), so the two function need to
called in RTNL lock, but bond_loadbalance_arp_mon()
only calling these functions in RCU, warning message
will occurs.

fix this by add a new function bond_slave_state_change(),
which will reset the slave's state after slave link check,
so remove the bond_set_xxx_slave() from the cycle and only
record the slave_state_changed, this will call the new
function to set all slaves to new state in RTNL later.

Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index dd75615d85f2d0dfb18911cd1ac0ab59ebad5cbb..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();
        }
 

diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
index 1a9062f4e0d6d4429d6cfb230867905b446615c5..86ccfb9f71cc4dd8c843f40f5eee38b7c0c033ab 100644 (file)
--- a/drivers/net/bonding/bonding.h
+++ b/drivers/net/bonding/bonding.h
@@ -303,6 +303,19 @@ static inline void bond_set_backup_slave(struct slave *slave)
        }
 }
 
+static inline void bond_slave_state_change(struct bonding *bond)
+{
+       struct list_head *iter;
+       struct slave *tmp;
+
+       bond_for_each_slave(bond, tmp, iter) {
+               if (tmp->link == BOND_LINK_UP)
+                       bond_set_active_slave(tmp);
+               else if (tmp->link == BOND_LINK_DOWN)
+                       bond_set_backup_slave(tmp);
+       }
+}
+
 static inline int bond_slave_state(struct slave *slave)
 {
        return slave->backup;