Commit 6fde8f03 authored by Ding Tianhong's avatar Ding Tianhong Committed by David S. Miller
Browse files

bonding: fix locking in bond_loadbalance_arp_mon() 



The commit 1d3ee88a
(bonding: add netlink attributes to slave link dev)
has add rtmsg_ifinfo() in bond_set_active_slave() and
bond_set_backup_slave(), so the two function need to
called in RTNL lock, but bond_loadbalance_arp_mon()
only calling these functions in RCU, warning message
will occurs.

fix this by add a new function bond_slave_state_change(),
which will reset the slave's state after slave link check,
so remove the bond_set_xxx_slave() from the cycle and only
record the slave_state_changed, this will call the new
function to set all slaves to new state in RTNL later.

Cc: Jay Vosburgh <fubar@us.ibm.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: default avatarDing Tianhong <dingtianhong@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 93e14b6d

drivers/net/bonding/bond_main.c

+17 −12
Original line number Diff line number Diff line
@@ -2346,7 +2346,7 @@ static void bond_loadbalance_arp_mon(struct work_struct *work) 
					    arp_work.work);

	struct slave *slave, *oldcurrent;

	struct list_head *iter;

	int do_failover = 0;

	int do_failover = 0, slave_state_changed = 0;



	if (!bond_has_slaves(bond))

		goto re_arm;
@@ -2370,7 +2370,7 @@ static void bond_loadbalance_arp_mon(struct work_struct *work) 
			    bond_time_in_interval(bond, slave->dev->last_rx, 1)) {



				slave->link  = BOND_LINK_UP;

				bond_set_active_slave(slave);

				slave_state_changed = 1;



				/* primary_slave has no meaning in round-robin

				 * mode. the window of a slave being up and
@@ -2399,7 +2399,7 @@ static void bond_loadbalance_arp_mon(struct work_struct *work) 
			    !bond_time_in_interval(bond, slave->dev->last_rx, 2)) {



				slave->link  = BOND_LINK_DOWN;

				bond_set_backup_slave(slave);

				slave_state_changed = 1;



				if (slave->link_failure_count < UINT_MAX)

					slave->link_failure_count++;
@@ -2426,12 +2426,16 @@ static void bond_loadbalance_arp_mon(struct work_struct *work) 


	rcu_read_unlock();



	if (do_failover) {

	if (do_failover || slave_state_changed) {

		if (!rtnl_trylock())

			goto re_arm;



		if (slave_state_changed) {

			bond_slave_state_change(bond);

		} else if (do_failover) {

			/* the bond_select_active_slave must hold RTNL

			 * and curr_slave_lock for write.

			 */

		if (!rtnl_trylock())

			goto re_arm;

			block_netpoll_tx();

			write_lock_bh(&bond->curr_slave_lock);
@@ -2439,6 +2443,7 @@ static void bond_loadbalance_arp_mon(struct work_struct *work) 


			write_unlock_bh(&bond->curr_slave_lock);

			unblock_netpoll_tx();

		}

		rtnl_unlock();

	}

drivers/net/bonding/bonding.h

+13 −0
Original line number Diff line number Diff line
@@ -303,6 +303,19 @@ static inline void bond_set_backup_slave(struct slave *slave) 
	}

}



static inline void bond_slave_state_change(struct bonding *bond)

{

	struct list_head *iter;

	struct slave *tmp;



	bond_for_each_slave(bond, tmp, iter) {

		if (tmp->link == BOND_LINK_UP)

			bond_set_active_slave(tmp);

		else if (tmp->link == BOND_LINK_DOWN)

			bond_set_backup_slave(tmp);

	}

}



static inline int bond_slave_state(struct slave *slave)

{

	return slave->backup;

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