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Commit 8fdd95ec authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
Browse files

netpoll: Allow netpoll_setup/cleanup recursion 



This patch adds the functions __netpoll_setup/__netpoll_cleanup
which is designed to be called recursively through ndo_netpoll_seutp.

They must be called with RTNL held, and the caller must initialise
np->dev and ensure that it has a valid reference count.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4247e161

include/linux/netpoll.h

+2 −0
Original line number Diff line number Diff line
@@ -46,9 +46,11 @@ void netpoll_poll(struct netpoll *np); 
void netpoll_send_udp(struct netpoll *np, const char *msg, int len);

void netpoll_print_options(struct netpoll *np);

int netpoll_parse_options(struct netpoll *np, char *opt);

int __netpoll_setup(struct netpoll *np);

int netpoll_setup(struct netpoll *np);

int netpoll_trap(void);

void netpoll_set_trap(int trap);

void __netpoll_cleanup(struct netpoll *np);

void netpoll_cleanup(struct netpoll *np);

int __netpoll_rx(struct sk_buff *skb);

void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);

net/core/netpoll.c

+97 −79
Original line number Diff line number Diff line
@@ -693,15 +693,78 @@ int netpoll_parse_options(struct netpoll *np, char *opt) 
	return -1;

}



int netpoll_setup(struct netpoll *np)

int __netpoll_setup(struct netpoll *np)

{

	struct net_device *ndev = NULL;

	struct in_device *in_dev;

	struct net_device *ndev = np->dev;

	struct netpoll_info *npinfo;

	const struct net_device_ops *ops;

	unsigned long flags;

	int err;



	if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||

	    !ndev->netdev_ops->ndo_poll_controller) {

		printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",

		       np->name, np->dev_name);

		err = -ENOTSUPP;

		goto out;

	}



	if (!ndev->npinfo) {

		npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);

		if (!npinfo) {

			err = -ENOMEM;

			goto out;

		}



		npinfo->rx_flags = 0;

		INIT_LIST_HEAD(&npinfo->rx_np);



		spin_lock_init(&npinfo->rx_lock);

		skb_queue_head_init(&npinfo->arp_tx);

		skb_queue_head_init(&npinfo->txq);

		INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);



		atomic_set(&npinfo->refcnt, 1);



		ops = np->dev->netdev_ops;

		if (ops->ndo_netpoll_setup) {

			err = ops->ndo_netpoll_setup(ndev, npinfo);

			if (err)

				goto free_npinfo;

		}

	} else {

		npinfo = ndev->npinfo;

		atomic_inc(&npinfo->refcnt);

	}



	npinfo->netpoll = np;



	if (np->rx_hook) {

		spin_lock_irqsave(&npinfo->rx_lock, flags);

		npinfo->rx_flags |= NETPOLL_RX_ENABLED;

		list_add_tail(&np->rx, &npinfo->rx_np);

		spin_unlock_irqrestore(&npinfo->rx_lock, flags);

	}



	/* last thing to do is link it to the net device structure */

	rcu_assign_pointer(ndev->npinfo, npinfo);

	rtnl_unlock();



	return 0;



free_npinfo:

	kfree(npinfo);

out:

	return err;

}

EXPORT_SYMBOL_GPL(__netpoll_setup);



int netpoll_setup(struct netpoll *np)

{

	struct net_device *ndev = NULL;

	struct in_device *in_dev;

	int err;



	if (np->dev_name)

		ndev = dev_get_by_name(&init_net, np->dev_name);

	if (!ndev) {
@@ -774,61 +837,14 @@ int netpoll_setup(struct netpoll *np) 
	refill_skbs();



	rtnl_lock();

	if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||

	    !ndev->netdev_ops->ndo_poll_controller) {

		printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",

		       np->name, np->dev_name);

		err = -ENOTSUPP;

		goto unlock;

	}



	if (!ndev->npinfo) {

		npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);

		if (!npinfo) {

			err = -ENOMEM;

			goto unlock;

		}



		npinfo->rx_flags = 0;

		INIT_LIST_HEAD(&npinfo->rx_np);



		spin_lock_init(&npinfo->rx_lock);

		skb_queue_head_init(&npinfo->arp_tx);

		skb_queue_head_init(&npinfo->txq);

		INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);



		atomic_set(&npinfo->refcnt, 1);

	err = __netpoll_setup(np);

	rtnl_unlock();



		ops = np->dev->netdev_ops;

		if (ops->ndo_netpoll_setup) {

			err = ops->ndo_netpoll_setup(ndev, npinfo);

	if (err)

				goto free_npinfo;

		}

	} else {

		npinfo = ndev->npinfo;

		atomic_inc(&npinfo->refcnt);

	}



	npinfo->netpoll = np;



	if (np->rx_hook) {

		spin_lock_irqsave(&npinfo->rx_lock, flags);

		npinfo->rx_flags |= NETPOLL_RX_ENABLED;

		list_add_tail(&np->rx, &npinfo->rx_np);

		spin_unlock_irqrestore(&npinfo->rx_lock, flags);

	}



	/* last thing to do is link it to the net device structure */

	rcu_assign_pointer(ndev->npinfo, npinfo);

	rtnl_unlock();

		goto put;



	return 0;



free_npinfo:

	kfree(npinfo);

unlock:

	rtnl_unlock();

put:

	dev_put(ndev);

	return err;
@@ -841,18 +857,15 @@ static int __init netpoll_init(void) 
}

core_initcall(netpoll_init);



void netpoll_cleanup(struct netpoll *np)

void __netpoll_cleanup(struct netpoll *np)

{

	struct netpoll_info *npinfo;

	unsigned long flags;

	int free = 0;



	if (!np->dev)

	npinfo = np->dev->npinfo;

	if (!npinfo)

		return;



	rtnl_lock();

	npinfo = np->dev->npinfo;

	if (npinfo) {

	if (!list_empty(&npinfo->rx_np)) {

		spin_lock_irqsave(&npinfo->rx_lock, flags);

		list_del(&np->rx);
@@ -861,8 +874,7 @@ void netpoll_cleanup(struct netpoll *np) 
		spin_unlock_irqrestore(&npinfo->rx_lock, flags);

	}



		free = atomic_dec_and_test(&npinfo->refcnt);

		if (free) {

	if (atomic_dec_and_test(&npinfo->refcnt)) {

		const struct net_device_ops *ops;



		ops = np->dev->netdev_ops;
@@ -870,11 +882,7 @@ void netpoll_cleanup(struct netpoll *np) 
			ops->ndo_netpoll_cleanup(np->dev);



		rcu_assign_pointer(np->dev->npinfo, NULL);

		}

	}

	rtnl_unlock();



	if (free) {

		/* avoid racing with NAPI reading npinfo */

		synchronize_rcu_bh();
@@ -886,9 +894,19 @@ void netpoll_cleanup(struct netpoll *np) 
		__skb_queue_purge(&npinfo->txq);

		kfree(npinfo);

	}

}

EXPORT_SYMBOL_GPL(__netpoll_cleanup);



	dev_put(np->dev);

void netpoll_cleanup(struct netpoll *np)

{

	if (!np->dev)

		return;



	rtnl_lock();

	__netpoll_cleanup(np);

	rtnl_unlock();



	dev_put(np->dev);

	np->dev = NULL;

}