bonding: fix alb mode locking regression
Jay Vosburgh [Mon, 4 May 2009 09:03:37 +0000 (09:03 +0000)]
Fix locking issue in alb MAC address management; removed
incorrect locking and replaced with correct locking.  This bug was
introduced in commit 059fe7a578fba5bbb0fdc0365bfcf6218fa25eb0
("bonding: Convert locks to _bh, rework alb locking for new locking")

Bug reported by Paul Smith <paul@mad-scientist.net>, who also
tested the fix.

Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_alb.c

index 553a899..46d312b 100644 (file)
@@ -1706,10 +1706,8 @@ void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave
  * Called with RTNL
  */
 int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
-       __releases(&bond->curr_slave_lock)
-       __releases(&bond->lock)
        __acquires(&bond->lock)
-       __acquires(&bond->curr_slave_lock)
+       __releases(&bond->lock)
 {
        struct bonding *bond = netdev_priv(bond_dev);
        struct sockaddr *sa = addr;
@@ -1745,9 +1743,6 @@ int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
                }
        }
 
-       write_unlock_bh(&bond->curr_slave_lock);
-       read_unlock(&bond->lock);
-
        if (swap_slave) {
                alb_swap_mac_addr(bond, swap_slave, bond->curr_active_slave);
                alb_fasten_mac_swap(bond, swap_slave, bond->curr_active_slave);
@@ -1755,16 +1750,15 @@ int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
                alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr,
                                       bond->alb_info.rlb_enabled);
 
+               read_lock(&bond->lock);
                alb_send_learning_packets(bond->curr_active_slave, bond_dev->dev_addr);
                if (bond->alb_info.rlb_enabled) {
                        /* inform clients mac address has changed */
                        rlb_req_update_slave_clients(bond, bond->curr_active_slave);
                }
+               read_unlock(&bond->lock);
        }
 
-       read_lock(&bond->lock);
-       write_lock_bh(&bond->curr_slave_lock);
-
        return 0;
 }