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Commit 4d961a10 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'bonding_monitor_locking' 



Ding Tianhong says:

====================
bonding: patchset for rcu use in bonding

The slave list will add and del by bond_master_upper_dev_link() and
bond_upper_dev_unlink(), which will call call_netdevice_notifiers(),
even it is safe to call it in write bond lock now, but we can't sure
that whether it is safe later, because other drivers may deal
NETDEV_CHANGEUPPER in sleep way, so I didn't admit move the
bond_upper_dev_unlink() in write bond lock.

now the bond_for_each_slave only protect by rtnl_lock(), maybe use
bond_for_each_slave_rcu is a good way to protect slave list for bond,
but as a system slow path, it is no need to transform
bond_for_each_slave() to bond_for_each_slave_rcu() in slow path, so in
the patchset, I will remove the unused read bond lock for monitor
function, maybe it is a better way, I will wait to accept any relay
for it.

Thanks for the Veaceslav Falico opinion.

v2: add and modify commit for patchset and patch, it will be the first
step for the whole patchset.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents a00f6fcc 5cc172c6

drivers/net/bonding/bond_3ad.c

+5 −4
Original line number Diff line number Diff line
@@ -2068,8 +2068,10 @@ void bond_3ad_state_machine_handler(struct work_struct *work) 
	struct slave *slave;

	struct port *port;



	read_lock(&bond->lock);



	if (!rtnl_trylock()) {

		queue_delayed_work(bond->wq, &bond->ad_work, ad_delta_in_ticks);

		return;

	}

	//check if there are any slaves

	if (!bond_has_slaves(bond))

		goto re_arm;
@@ -2122,9 +2124,8 @@ void bond_3ad_state_machine_handler(struct work_struct *work) 
	}



re_arm:

	rtnl_unlock();

	queue_delayed_work(bond->wq, &bond->ad_work, ad_delta_in_ticks);



	read_unlock(&bond->lock);

}



/**

drivers/net/bonding/bond_alb.c

+4 −16
Original line number Diff line number Diff line
@@ -1495,11 +1495,13 @@ void bond_alb_monitor(struct work_struct *work) 
	struct list_head *iter;

	struct slave *slave;



	read_lock(&bond->lock);

	if (!rtnl_trylock())

		goto re_arm;



	if (!bond_has_slaves(bond)) {

		bond_info->tx_rebalance_counter = 0;

		bond_info->lp_counter = 0;

		rtnl_unlock();

		goto re_arm;

	}
@@ -1548,16 +1550,6 @@ void bond_alb_monitor(struct work_struct *work) 
		if (bond_info->primary_is_promisc &&

		    (++bond_info->rlb_promisc_timeout_counter >= RLB_PROMISC_TIMEOUT)) {



			/*

			 * dev_set_promiscuity requires rtnl and

			 * nothing else.  Avoid race with bond_close.

			 */

			read_unlock(&bond->lock);

			if (!rtnl_trylock()) {

				read_lock(&bond->lock);

				goto re_arm;

			}



			bond_info->rlb_promisc_timeout_counter = 0;



			/* If the primary was set to promiscuous mode
@@ -1566,9 +1558,6 @@ void bond_alb_monitor(struct work_struct *work) 
			 */

			dev_set_promiscuity(bond->curr_active_slave->dev, -1);

			bond_info->primary_is_promisc = 0;



			rtnl_unlock();

			read_lock(&bond->lock);

		}



		if (bond_info->rlb_rebalance) {
@@ -1591,10 +1580,9 @@ void bond_alb_monitor(struct work_struct *work) 
		}

	}



	rtnl_unlock();

re_arm:

	queue_delayed_work(bond->wq, &bond->alb_work, alb_delta_in_ticks);



	read_unlock(&bond->lock);

}



/* assumption: called before the slave is attached to the bond

drivers/net/bonding/bond_main.c

+31 −69
Original line number Diff line number Diff line
@@ -2118,49 +2118,29 @@ void bond_mii_monitor(struct work_struct *work) 
	struct bonding *bond = container_of(work, struct bonding,

					    mii_work.work);

	bool should_notify_peers = false;

	unsigned long delay;



	read_lock(&bond->lock);



	delay = msecs_to_jiffies(bond->params.miimon);



	if (!bond_has_slaves(bond))

	if (!rtnl_trylock())

		goto re_arm;



	should_notify_peers = bond_should_notify_peers(bond);



	if (bond_miimon_inspect(bond)) {

		read_unlock(&bond->lock);



		/* Race avoidance with bond_close cancel of workqueue */

		if (!rtnl_trylock()) {

			read_lock(&bond->lock);

			delay = 1;

			should_notify_peers = false;

	if (!bond_has_slaves(bond)) {

		rtnl_unlock();

		goto re_arm;

	}



		read_lock(&bond->lock);

	should_notify_peers = bond_should_notify_peers(bond);



	if (bond_miimon_inspect(bond))

		bond_miimon_commit(bond);



		read_unlock(&bond->lock);

		rtnl_unlock();	/* might sleep, hold no other locks */

		read_lock(&bond->lock);

	}

	if (should_notify_peers)

		call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev);



	rtnl_unlock();



re_arm:

	if (bond->params.miimon)

		queue_delayed_work(bond->wq, &bond->mii_work, delay);



	read_unlock(&bond->lock);



	if (should_notify_peers) {

		if (!rtnl_trylock())

			return;

		call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev);

		rtnl_unlock();

	}

		queue_delayed_work(bond->wq, &bond->mii_work,

				msecs_to_jiffies(bond->params.miimon));

}



static bool bond_has_this_ip(struct bonding *bond, __be32 ip)
@@ -2416,10 +2396,13 @@ void bond_loadbalance_arp_mon(struct work_struct *work) 
	struct list_head *iter;

	int do_failover = 0;



	read_lock(&bond->lock);

	if (!rtnl_trylock())

		goto re_arm;



	if (!bond_has_slaves(bond))

	if (!bond_has_slaves(bond)) {

		rtnl_unlock();

		goto re_arm;

	}



	oldcurrent = bond->curr_active_slave;

	/* see if any of the previous devices are up now (i.e. they have
@@ -2501,13 +2484,12 @@ void bond_loadbalance_arp_mon(struct work_struct *work) 
		write_unlock_bh(&bond->curr_slave_lock);

		unblock_netpoll_tx();

	}

	rtnl_unlock();



re_arm:

	if (bond->params.arp_interval)

		queue_delayed_work(bond->wq, &bond->arp_work,

				   msecs_to_jiffies(bond->params.arp_interval));



	read_unlock(&bond->lock);

}



/*
@@ -2744,51 +2726,31 @@ void bond_activebackup_arp_mon(struct work_struct *work) 
	struct bonding *bond = container_of(work, struct bonding,

					    arp_work.work);

	bool should_notify_peers = false;

	int delta_in_ticks;



	read_lock(&bond->lock);



	delta_in_ticks = msecs_to_jiffies(bond->params.arp_interval);



	if (!bond_has_slaves(bond))

	if (!rtnl_trylock())

		goto re_arm;



	should_notify_peers = bond_should_notify_peers(bond);



	if (bond_ab_arp_inspect(bond)) {

		read_unlock(&bond->lock);



		/* Race avoidance with bond_close flush of workqueue */

		if (!rtnl_trylock()) {

			read_lock(&bond->lock);

			delta_in_ticks = 1;

			should_notify_peers = false;

	if (!bond_has_slaves(bond)) {

		rtnl_unlock();

		goto re_arm;

	}



		read_lock(&bond->lock);

	should_notify_peers = bond_should_notify_peers(bond);



	if (bond_ab_arp_inspect(bond))

		bond_ab_arp_commit(bond);



		read_unlock(&bond->lock);

		rtnl_unlock();

		read_lock(&bond->lock);

	}



	bond_ab_arp_probe(bond);



re_arm:

	if (bond->params.arp_interval)

		queue_delayed_work(bond->wq, &bond->arp_work, delta_in_ticks);



	read_unlock(&bond->lock);



	if (should_notify_peers) {

		if (!rtnl_trylock())

			return;

	if (should_notify_peers)

		call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, bond->dev);



	rtnl_unlock();

	}



re_arm:

	if (bond->params.arp_interval)

		queue_delayed_work(bond->wq, &bond->arp_work,

				msecs_to_jiffies(bond->params.arp_interval));

}



/*-------------------------- netdev event handling --------------------------*/