From 2543331d367c9fe54f4ba73300894bc21e0a08f4 Mon Sep 17 00:00:00 2001 From: Jay Vosburgh Date: Thu, 17 Jan 2008 16:24:59 -0800 Subject: [PATCH] bonding: fix locking during alb failover and slave removal alb_fasten_mac_swap (actually rlb_teach_disabled_mac_on_primary) requries RTNL and no other locks. This could cause dev_set_promiscuity and/or dev_set_mac_address to be called with improper locking. Changed callers to hold only RTNL during calls to alb_fasten_mac_swap or functions calling it. Updated header comments in affected functions to reflect proper reality of locking requirements. Signed-off-by: Jay Vosburgh Signed-off-by: Jeff Garzik --- drivers/net/bonding/bond_alb.c | 18 ++++++++++++------ drivers/net/bonding/bond_main.c | 14 ++++++++------ 2 files changed, 20 insertions(+), 12 deletions(-) diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c index 9b55a123c08f..b57bc9467dbe 100644 --- a/drivers/net/bonding/bond_alb.c +++ b/drivers/net/bonding/bond_alb.c @@ -979,7 +979,7 @@ static void alb_swap_mac_addr(struct bonding *bond, struct slave *slave1, struct /* * Send learning packets after MAC address swap. * - * Called with RTNL and bond->lock held for read. + * Called with RTNL and no other locks */ static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1, struct slave *slave2) @@ -987,6 +987,8 @@ static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1, int slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2)); struct slave *disabled_slave = NULL; + ASSERT_RTNL(); + /* fasten the change in the switch */ if (SLAVE_IS_OK(slave1)) { alb_send_learning_packets(slave1, slave1->dev->dev_addr); @@ -1031,7 +1033,7 @@ static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1, * a slave that has @slave's permanet address as its current address. * We'll make sure that that slave no longer uses @slave's permanent address. * - * Caller must hold bond lock + * Caller must hold RTNL and no other locks */ static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *slave) { @@ -1542,7 +1544,12 @@ int bond_alb_init_slave(struct bonding *bond, struct slave *slave) return 0; } -/* Caller must hold bond lock for write */ +/* + * Remove slave from tlb and rlb hash tables, and fix up MAC addresses + * if necessary. + * + * Caller must hold RTNL and no other locks + */ void bond_alb_deinit_slave(struct bonding *bond, struct slave *slave) { if (bond->slave_cnt > 1) { @@ -1658,12 +1665,11 @@ void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave bond->alb_info.rlb_enabled); } - read_lock(&bond->lock); - if (swap_slave) { alb_fasten_mac_swap(bond, swap_slave, new_slave); + read_lock(&bond->lock); } else { - /* fasten bond mac on new current slave */ + read_lock(&bond->lock); alb_send_learning_packets(new_slave, bond->dev->dev_addr); } diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index b0b26036266b..77d004d3c554 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1746,7 +1746,9 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev) * has been cleared (if our_slave == old_current), * but before a new active slave is selected. */ + write_unlock_bh(&bond->lock); bond_alb_deinit_slave(bond, slave); + write_lock_bh(&bond->lock); } if (oldcurrent == slave) { @@ -1905,6 +1907,12 @@ static int bond_release_all(struct net_device *bond_dev) slave_dev = slave->dev; bond_detach_slave(bond, slave); + /* now that the slave is detached, unlock and perform + * all the undo steps that should not be called from + * within a lock. + */ + write_unlock_bh(&bond->lock); + if ((bond->params.mode == BOND_MODE_TLB) || (bond->params.mode == BOND_MODE_ALB)) { /* must be called only after the slave @@ -1915,12 +1923,6 @@ static int bond_release_all(struct net_device *bond_dev) bond_compute_features(bond); - /* now that the slave is detached, unlock and perform - * all the undo steps that should not be called from - * within a lock. - */ - write_unlock_bh(&bond->lock); - bond_destroy_slave_symlinks(bond_dev, slave_dev); bond_del_vlans_from_slave(bond, slave_dev); -- 2.20.1