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Date: Wed, 17 Oct 2007 17:37:49 -0700
From: Jay Vosburgh <fubar@...ibm.com>
To: netdev@...r.kernel.org, jgarzik@...ox.com
Cc: andy@...yhouse.net, Jay Vosburgh <fubar@...ibm.com>
Subject: [PATCH 4/6] Convert locks to _bh, rework alb locking for new locking
Convert locking-related activity to new & improved system.
Convert some lock acquisitions to _bh and rework parts of ALB mode, both
to avoid deadlocks with workqueue activity.
Signed-off-by: Andy Gospodarek <andy@...yhouse.net>
Signed-off-by: Jay Vosburgh <fubar@...ibm.com>
---
drivers/net/bonding/bond_alb.c | 69 +++++++++++++++++++++++++++++++---
drivers/net/bonding/bond_main.c | 78 +++++++++++++++++++++++++++------------
2 files changed, 117 insertions(+), 30 deletions(-)
diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index eb320c3..f2e2872 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c
@@ -959,19 +959,34 @@ static int alb_set_slave_mac_addr(struct slave *slave, u8 addr[], int hw)
return 0;
}
-/* Caller must hold bond lock for write or curr_slave_lock for write*/
+/*
+ * Swap MAC addresses between two slaves.
+ *
+ * Called with RTNL held, and no other locks.
+ *
+ */
+
static void alb_swap_mac_addr(struct bonding *bond, struct slave *slave1, struct slave *slave2)
{
- struct slave *disabled_slave = NULL;
u8 tmp_mac_addr[ETH_ALEN];
- int slaves_state_differ;
-
- slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2));
memcpy(tmp_mac_addr, slave1->dev->dev_addr, ETH_ALEN);
alb_set_slave_mac_addr(slave1, slave2->dev->dev_addr, bond->alb_info.rlb_enabled);
alb_set_slave_mac_addr(slave2, tmp_mac_addr, bond->alb_info.rlb_enabled);
+}
+
+/*
+ * Send learning packets after MAC address swap.
+ *
+ * Called with RTNL and bond->lock held for read.
+ */
+static void alb_fasten_mac_swap(struct bonding *bond, struct slave *slave1,
+ struct slave *slave2)
+{
+ int slaves_state_differ = (SLAVE_IS_OK(slave1) != SLAVE_IS_OK(slave2));
+ struct slave *disabled_slave = NULL;
+
/* fasten the change in the switch */
if (SLAVE_IS_OK(slave1)) {
alb_send_learning_packets(slave1, slave1->dev->dev_addr);
@@ -1044,7 +1059,9 @@ static void alb_change_hw_addr_on_detach(struct bonding *bond, struct slave *sla
}
if (found) {
+ /* locking: needs RTNL and nothing else */
alb_swap_mac_addr(bond, slave, tmp_slave);
+ alb_fasten_mac_swap(bond, slave, tmp_slave);
}
}
}
@@ -1571,13 +1588,21 @@ void bond_alb_handle_link_change(struct bonding *bond, struct slave *slave, char
* Set the bond->curr_active_slave to @new_slave and handle
* mac address swapping and promiscuity changes as needed.
*
- * Caller must hold bond curr_slave_lock for write (or bond lock for write)
+ * If new_slave is NULL, caller must hold curr_slave_lock or
+ * bond->lock for write.
+ *
+ * If new_slave is not NULL, caller must hold RTNL, bond->lock for
+ * read and curr_slave_lock for write. Processing here may sleep, so
+ * no other locks may be held.
*/
void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave)
{
struct slave *swap_slave;
int i;
+ if (new_slave)
+ ASSERT_RTNL();
+
if (bond->curr_active_slave == new_slave) {
return;
}
@@ -1610,6 +1635,19 @@ void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave
}
}
+ /*
+ * Arrange for swap_slave and new_slave to temporarily be
+ * ignored so we can mess with their MAC addresses without
+ * fear of interference from transmit activity.
+ */
+ if (swap_slave) {
+ tlb_clear_slave(bond, swap_slave, 1);
+ }
+ tlb_clear_slave(bond, new_slave, 1);
+
+ write_unlock_bh(&bond->curr_slave_lock);
+ read_unlock(&bond->lock);
+
/* curr_active_slave must be set before calling alb_swap_mac_addr */
if (swap_slave) {
/* swap mac address */
@@ -1618,11 +1656,23 @@ void bond_alb_handle_active_change(struct bonding *bond, struct slave *new_slave
/* set the new_slave to the bond mac address */
alb_set_slave_mac_addr(new_slave, bond->dev->dev_addr,
bond->alb_info.rlb_enabled);
+ }
+
+ read_lock(&bond->lock);
+
+ if (swap_slave) {
+ alb_fasten_mac_swap(bond, swap_slave, new_slave);
+ } else {
/* fasten bond mac on new current slave */
alb_send_learning_packets(new_slave, bond->dev->dev_addr);
}
+
+ write_lock_bh(&bond->curr_slave_lock);
}
+/*
+ * Called with RTNL
+ */
int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
{
struct bonding *bond = bond_dev->priv;
@@ -1659,8 +1709,12 @@ 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);
} else {
alb_set_slave_mac_addr(bond->curr_active_slave, bond_dev->dev_addr,
bond->alb_info.rlb_enabled);
@@ -1672,6 +1726,9 @@ int bond_alb_set_mac_address(struct net_device *bond_dev, void *addr)
}
}
+ read_lock(&bond->lock);
+ write_lock_bh(&bond->curr_slave_lock);
+
return 0;
}
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index a357727..15c1f7a 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1590,15 +1590,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
case BOND_MODE_TLB:
case BOND_MODE_ALB:
new_slave->state = BOND_STATE_ACTIVE;
- if ((!bond->curr_active_slave) &&
- (new_slave->link != BOND_LINK_DOWN)) {
- /* first slave or no active slave yet, and this link
- * is OK, so make this interface the active one
- */
- bond_change_active_slave(bond, new_slave);
- } else {
- bond_set_slave_inactive_flags(new_slave);
- }
+ bond_set_slave_inactive_flags(new_slave);
break;
default:
dprintk("This slave is always active in trunk mode\n");
@@ -1754,9 +1746,23 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
bond_alb_deinit_slave(bond, slave);
}
- if (oldcurrent == slave)
+ if (oldcurrent == slave) {
+ /*
+ * Note that we hold RTNL over this sequence, so there
+ * is no concern that another slave add/remove event
+ * will interfere.
+ */
+ write_unlock_bh(&bond->lock);
+ read_lock(&bond->lock);
+ write_lock_bh(&bond->curr_slave_lock);
+
bond_select_active_slave(bond);
+ write_unlock_bh(&bond->curr_slave_lock);
+ read_unlock(&bond->lock);
+ write_lock_bh(&bond->lock);
+ }
+
if (bond->slave_cnt == 0) {
bond_set_carrier(bond);
@@ -2012,16 +2018,19 @@ static int bond_ioctl_change_active(struct net_device *bond_dev, struct net_devi
return -EINVAL;
}
- write_lock_bh(&bond->lock);
+ read_lock(&bond->lock);
+ read_lock(&bond->curr_slave_lock);
old_active = bond->curr_active_slave;
+ read_unlock(&bond->curr_slave_lock);
+
new_active = bond_get_slave_by_dev(bond, slave_dev);
/*
* Changing to the current active: do nothing; return success.
*/
if (new_active && (new_active == old_active)) {
- write_unlock_bh(&bond->lock);
+ read_unlock(&bond->lock);
return 0;
}
@@ -2029,12 +2038,14 @@ static int bond_ioctl_change_active(struct net_device *bond_dev, struct net_devi
(old_active) &&
(new_active->link == BOND_LINK_UP) &&
IS_UP(new_active->dev)) {
+ write_lock_bh(&bond->curr_slave_lock);
bond_change_active_slave(bond, new_active);
+ write_unlock_bh(&bond->curr_slave_lock);
} else {
res = -EINVAL;
}
- write_unlock_bh(&bond->lock);
+ read_unlock(&bond->lock);
return res;
}
@@ -2140,7 +2151,11 @@ static int __bond_mii_monitor(struct bonding *bond, int have_locks)
switch (slave->link) {
case BOND_LINK_UP: /* the link was up */
if (link_state == BMSR_LSTATUS) {
- /* link stays up, nothing more to do */
+ if (!oldcurrent) {
+ if (!have_locks)
+ return 1;
+ do_failover = 1;
+ }
break;
} else { /* link going down */
slave->link = BOND_LINK_FAIL;
@@ -2327,11 +2342,14 @@ static int __bond_mii_monitor(struct bonding *bond, int have_locks)
} /* end of for */
if (do_failover) {
- write_lock(&bond->curr_slave_lock);
+ ASSERT_RTNL();
+
+ write_lock_bh(&bond->curr_slave_lock);
bond_select_active_slave(bond);
- write_unlock(&bond->curr_slave_lock);
+ write_unlock_bh(&bond->curr_slave_lock);
+
} else
bond_set_carrier(bond);
@@ -2770,11 +2788,14 @@ void bond_loadbalance_arp_mon(struct work_struct *work)
}
if (do_failover) {
- write_lock(&bond->curr_slave_lock);
+ rtnl_lock();
+ write_lock_bh(&bond->curr_slave_lock);
bond_select_active_slave(bond);
- write_unlock(&bond->curr_slave_lock);
+ write_unlock_bh(&bond->curr_slave_lock);
+ rtnl_unlock();
+
}
re_arm:
@@ -2831,7 +2852,9 @@ void bond_activebackup_arp_mon(struct work_struct *work)
slave->link = BOND_LINK_UP;
- write_lock(&bond->curr_slave_lock);
+ rtnl_lock();
+
+ write_lock_bh(&bond->curr_slave_lock);
if ((!bond->curr_active_slave) &&
((jiffies - slave->dev->trans_start) <= delta_in_ticks)) {
@@ -2865,7 +2888,8 @@ void bond_activebackup_arp_mon(struct work_struct *work)
slave->dev->name);
}
- write_unlock(&bond->curr_slave_lock);
+ write_unlock_bh(&bond->curr_slave_lock);
+ rtnl_unlock();
}
} else {
read_lock(&bond->curr_slave_lock);
@@ -2935,12 +2959,15 @@ void bond_activebackup_arp_mon(struct work_struct *work)
bond->dev->name,
slave->dev->name);
- write_lock(&bond->curr_slave_lock);
+ rtnl_lock();
+ write_lock_bh(&bond->curr_slave_lock);
bond_select_active_slave(bond);
slave = bond->curr_active_slave;
- write_unlock(&bond->curr_slave_lock);
+ write_unlock_bh(&bond->curr_slave_lock);
+
+ rtnl_unlock();
bond->current_arp_slave = slave;
@@ -2959,9 +2986,12 @@ void bond_activebackup_arp_mon(struct work_struct *work)
bond->primary_slave->dev->name);
/* primary is up so switch to it */
- write_lock(&bond->curr_slave_lock);
+ rtnl_lock();
+ write_lock_bh(&bond->curr_slave_lock);
bond_change_active_slave(bond, bond->primary_slave);
- write_unlock(&bond->curr_slave_lock);
+ write_unlock_bh(&bond->curr_slave_lock);
+
+ rtnl_unlock();
slave = bond->primary_slave;
slave->jiffies = jiffies;
--
1.5.3.4.206.g58ba4-dirty
-
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