From 2543331d367c9fe54f4ba73300894bc21e0a08f4 Mon Sep 17 00:00:00 2001
From: Jay Vosburgh <fubar@us.ibm.com>
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 <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
---
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);
--
2.34.1