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Commit cda8daf1 authored by Erez Shitrit's avatar Erez Shitrit Committed by Jason Gunthorpe
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IB/ipoib: Use cancel_delayed_work_sync for neigh-clean task 



The neigh_reap_task is self restarting, but so long as we call
cancel_delayed_work_sync() it will be guaranteed to not be running and
never start again. Thus we don't need to have the racy
IPOIB_STOP_NEIGH_GC bit, or the confusing mismatch of places sometimes
calling flush_workqueue after the cancel.

This fixes a situation where the GC work could have been left running
in some rare situations.

Signed-off-by: default avatarErez Shitrit <erezsh@mellanox.com>
Signed-off-by: default avatarLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 577e07ff

drivers/infiniband/ulp/ipoib/ipoib.h

+0 −1
Original line number Diff line number Diff line
@@ -91,7 +91,6 @@ enum { 
	IPOIB_STOP_REAPER	  = 7,

	IPOIB_FLAG_ADMIN_CM	  = 9,

	IPOIB_FLAG_UMCAST	  = 10,

	IPOIB_STOP_NEIGH_GC	  = 11,

	IPOIB_NEIGH_TBL_FLUSH	  = 12,

	IPOIB_FLAG_DEV_ADDR_SET	  = 13,

	IPOIB_FLAG_DEV_ADDR_CTRL  = 14,

drivers/infiniband/ulp/ipoib/ipoib_main.c

+10 −23
Original line number Diff line number Diff line
@@ -1310,9 +1310,6 @@ static void __ipoib_reap_neigh(struct ipoib_dev_priv *priv) 
	int i;

	LIST_HEAD(remove_list);



	if (test_bit(IPOIB_STOP_NEIGH_GC, &priv->flags))

		return;



	spin_lock_irqsave(&priv->lock, flags);



	htbl = rcu_dereference_protected(ntbl->htbl,
@@ -1324,9 +1321,6 @@ static void __ipoib_reap_neigh(struct ipoib_dev_priv *priv) 
	/* neigh is obsolete if it was idle for two GC periods */

	dt = 2 * arp_tbl.gc_interval;

	neigh_obsolete = jiffies - dt;

	/* handle possible race condition */

	if (test_bit(IPOIB_STOP_NEIGH_GC, &priv->flags))

		goto out_unlock;



	for (i = 0; i < htbl->size; i++) {

		struct ipoib_neigh *neigh;
@@ -1364,7 +1358,6 @@ static void ipoib_reap_neigh(struct work_struct *work) 


	__ipoib_reap_neigh(priv);



	if (!test_bit(IPOIB_STOP_NEIGH_GC, &priv->flags))

	queue_delayed_work(priv->wq, &priv->neigh_reap_task,

			   arp_tbl.gc_interval);

}
@@ -1528,7 +1521,6 @@ static int ipoib_neigh_hash_init(struct ipoib_dev_priv *priv) 
	htbl = kzalloc(sizeof(*htbl), GFP_KERNEL);

	if (!htbl)

		return -ENOMEM;

	set_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);

	size = roundup_pow_of_two(arp_tbl.gc_thresh3);

	buckets = kvcalloc(size, sizeof(*buckets), GFP_KERNEL);

	if (!buckets) {
@@ -1543,7 +1535,6 @@ static int ipoib_neigh_hash_init(struct ipoib_dev_priv *priv) 
	atomic_set(&ntbl->entries, 0);



	/* start garbage collection */

	clear_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);

	queue_delayed_work(priv->wq, &priv->neigh_reap_task,

			   arp_tbl.gc_interval);
@@ -1653,15 +1644,11 @@ static void ipoib_flush_neighs(struct ipoib_dev_priv *priv) 
static void ipoib_neigh_hash_uninit(struct net_device *dev)

{

	struct ipoib_dev_priv *priv = ipoib_priv(dev);

	int stopped;



	ipoib_dbg(priv, "ipoib_neigh_hash_uninit\n");

	init_completion(&priv->ntbl.deleted);



	/* Stop GC if called at init fail need to cancel work */

	stopped = test_and_set_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);

	if (!stopped)

		cancel_delayed_work(&priv->neigh_reap_task);

	cancel_delayed_work_sync(&priv->neigh_reap_task);



	ipoib_flush_neighs(priv);
@@ -1801,12 +1788,15 @@ int ipoib_dev_init(struct net_device *dev, struct ib_device *ca, int port) 
		if (ipoib_ib_dev_open(dev)) {

			pr_warn("%s failed to open device\n", dev->name);

			ret = -ENODEV;

			goto out_dev_uninit;

			goto out_hash_uninit;

		}

	}



	return 0;



out_hash_uninit:

	ipoib_neigh_hash_uninit(dev);



out_dev_uninit:

	ipoib_ib_dev_cleanup(dev);
@@ -1836,8 +1826,7 @@ void ipoib_dev_cleanup(struct net_device *dev) 
	/* Delete any child interfaces first */

	list_for_each_entry_safe(cpriv, tcpriv, &priv->child_intfs, list) {

		/* Stop GC on child */

		set_bit(IPOIB_STOP_NEIGH_GC, &cpriv->flags);

		cancel_delayed_work(&cpriv->neigh_reap_task);

		cancel_delayed_work_sync(&cpriv->neigh_reap_task);

		unregister_netdevice_queue(cpriv->dev, &head);

	}

	unregister_netdevice_many(&head);
@@ -2345,8 +2334,7 @@ static struct net_device *ipoib_add_port(const char *format, 
	ib_unregister_event_handler(&priv->event_handler);

	flush_workqueue(ipoib_workqueue);

	/* Stop GC if started before flush */

	set_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);

	cancel_delayed_work(&priv->neigh_reap_task);

	cancel_delayed_work_sync(&priv->neigh_reap_task);

	flush_workqueue(priv->wq);

	ipoib_dev_cleanup(priv->dev);
@@ -2411,8 +2399,7 @@ static void ipoib_remove_one(struct ib_device *device, void *client_data) 
		rtnl_unlock();



		/* Stop GC */

		set_bit(IPOIB_STOP_NEIGH_GC, &priv->flags);

		cancel_delayed_work(&priv->neigh_reap_task);

		cancel_delayed_work_sync(&priv->neigh_reap_task);

		flush_workqueue(priv->wq);



		/* Wrap rtnl_lock/unlock with mutex to protect sysfs calls */