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Commit 059fe7a5 authored by Jay Vosburgh's avatar Jay Vosburgh Committed by Jeff Garzik
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bonding: 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: default avatarAndy Gospodarek <andy@greyhouse.net>
Signed-off-by: default avatarJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 0b0eef66
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+63 −6
Original line number Diff line number Diff line
@@ -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;
}

+54 −24
Original line number Diff line number Diff line
@@ -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);
		}
		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;