---

yaml
---
r: 352104
b: refs/heads/master
c: ca99ca1
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f458c647ea5cdd956f8055a4178072be460559f1
+refs/heads/master: ca99ca14c95ae49fb4c9cd3abf5f84d11a7e8a61

trunk/include/linux/netpoll.h

@@ -38,8 +38,9 @@ struct netpoll {
 struct netpoll_info {
 	atomic_t refcnt;
 
-	int rx_flags;
+	unsigned long rx_flags;
 	spinlock_t rx_lock;
+	struct mutex dev_lock;
 	struct list_head rx_np; /* netpolls that registered an rx_hook */
 
 	struct sk_buff_head neigh_tx; /* list of neigh requests to reply to */
@@ -51,6 +52,14 @@ struct netpoll_info {
 	struct rcu_head rcu;
 };
 
+#ifdef CONFIG_NETPOLL
+extern int netpoll_rx_disable(struct net_device *dev);
+extern void netpoll_rx_enable(struct net_device *dev);
+#else
+static inline int netpoll_rx_disable(struct net_device *dev) { return 0; }
+static inline void netpoll_rx_enable(struct net_device *dev) { return; }
+#endif
+
 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);

trunk/net/core/dev.c

@@ -1266,6 +1266,14 @@ static int __dev_open(struct net_device *dev)
 	if (!netif_device_present(dev))
 		return -ENODEV;
 
+	/* Block netpoll from trying to do any rx path servicing.
+	 * If we don't do this there is a chance ndo_poll_controller
+	 * or ndo_poll may be running while we open the device
+	 */
+	ret = netpoll_rx_disable(dev);
+	if (ret)
+		return ret;
+
 	ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
 	ret = notifier_to_errno(ret);
 	if (ret)
@@ -1279,6 +1287,8 @@ static int __dev_open(struct net_device *dev)
 	if (!ret && ops->ndo_open)
 		ret = ops->ndo_open(dev);
 
+	netpoll_rx_enable(dev);
+
 	if (ret)
 		clear_bit(__LINK_STATE_START, &dev->state);
 	else {
@@ -1370,9 +1380,16 @@ static int __dev_close(struct net_device *dev)
 	int retval;
 	LIST_HEAD(single);
 
+	/* Temporarily disable netpoll until the interface is down */
+	retval = netpoll_rx_disable(dev);
+	if (retval)
+		return retval;
+
 	list_add(&dev->unreg_list, &single);
 	retval = __dev_close_many(&single);
 	list_del(&single);
+
+	netpoll_rx_enable(dev);
 	return retval;
 }
 
@@ -1408,14 +1425,22 @@ static int dev_close_many(struct list_head *head)
  */
 int dev_close(struct net_device *dev)
 {
+	int ret = 0;
 	if (dev->flags & IFF_UP) {
 		LIST_HEAD(single);
 
+		/* Block netpoll rx while the interface is going down */
+		ret = netpoll_rx_disable(dev);
+		if (ret)
+			return ret;
+
 		list_add(&dev->unreg_list, &single);
 		dev_close_many(&single);
 		list_del(&single);
+
+		netpoll_rx_enable(dev);
 	}
-	return 0;
+	return ret;
 }
 EXPORT_SYMBOL(dev_close);
 

trunk/net/core/netpoll.c

@@ -47,6 +47,8 @@ static struct sk_buff_head skb_pool;
 
 static atomic_t trapped;
 
+static struct srcu_struct netpoll_srcu;
+
 #define USEC_PER_POLL	50
 #define NETPOLL_RX_ENABLED  1
 #define NETPOLL_RX_DROP     2
@@ -199,6 +201,13 @@ static void netpoll_poll_dev(struct net_device *dev)
 	const struct net_device_ops *ops;
 	struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
 
+	/* Don't do any rx activity if the dev_lock mutex is held
+	 * the dev_open/close paths use this to block netpoll activity
+	 * while changing device state
+	 */
+	if (!mutex_trylock(&dev->npinfo->dev_lock))
+		return;
+
 	if (!dev || !netif_running(dev))
 		return;
 
@@ -211,6 +220,8 @@ static void netpoll_poll_dev(struct net_device *dev)
 
 	poll_napi(dev);
 
+	mutex_unlock(&dev->npinfo->dev_lock);
+
 	if (dev->flags & IFF_SLAVE) {
 		if (ni) {
 			struct net_device *bond_dev;
@@ -231,6 +242,31 @@ static void netpoll_poll_dev(struct net_device *dev)
 	zap_completion_queue();
 }
 
+int netpoll_rx_disable(struct net_device *dev)
+{
+	struct netpoll_info *ni;
+	int idx;
+	might_sleep();
+	idx = srcu_read_lock(&netpoll_srcu);
+	ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
+	if (ni)
+		mutex_lock(&ni->dev_lock);
+	srcu_read_unlock(&netpoll_srcu, idx);
+	return 0;
+}
+EXPORT_SYMBOL(netpoll_rx_disable);
+
+void netpoll_rx_enable(struct net_device *dev)
+{
+	struct netpoll_info *ni;
+	rcu_read_lock();
+	ni = rcu_dereference(dev->npinfo);
+	if (ni)
+		mutex_unlock(&ni->dev_lock);
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(netpoll_rx_enable);
+
 static void refill_skbs(void)
 {
 	struct sk_buff *skb;
@@ -1004,6 +1040,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
 		INIT_LIST_HEAD(&npinfo->rx_np);
 
 		spin_lock_init(&npinfo->rx_lock);
+		mutex_init(&npinfo->dev_lock);
 		skb_queue_head_init(&npinfo->neigh_tx);
 		skb_queue_head_init(&npinfo->txq);
 		INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
@@ -1169,6 +1206,7 @@ EXPORT_SYMBOL(netpoll_setup);
 static int __init netpoll_init(void)
 {
 	skb_queue_head_init(&skb_pool);
+	init_srcu_struct(&netpoll_srcu);
 	return 0;
 }
 core_initcall(netpoll_init);
@@ -1208,6 +1246,8 @@ void __netpoll_cleanup(struct netpoll *np)
 		spin_unlock_irqrestore(&npinfo->rx_lock, flags);
 	}
 
+	synchronize_srcu(&netpoll_srcu);
+
 	if (atomic_dec_and_test(&npinfo->refcnt)) {
 		const struct net_device_ops *ops;