1 files changed, 10 insertions, 31 deletions

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 57557a6a950c..de1d1ba92f2d 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -135,27 +135,9 @@ static void queue_process(struct work_struct *work)
 	}
 }
 
-/*
- * Check whether delayed processing was scheduled for our NIC. If so,
- * we attempt to grab the poll lock and use ->poll() to pump the card.
- * If this fails, either we've recursed in ->poll() or it's already
- * running on another CPU.
- *
- * Note: we don't mask interrupts with this lock because we're using
- * trylock here and interrupts are already disabled in the softirq
- * case. Further, we test the poll_owner to avoid recursion on UP
- * systems where the lock doesn't exist.
- */
 static void poll_one_napi(struct napi_struct *napi)
 {
-	int work = 0;
-
-	/* net_rx_action's ->poll() invocations and our's are
-	 * synchronized by this test which is only made while
-	 * holding the napi->poll_lock.
-	 */
-	if (!test_bit(NAPI_STATE_SCHED, &napi->state))
-		return;
+	int work;
 
 	/* If we set this bit but see that it has already been set,
 	 * that indicates that napi has been disabled and we need
@@ -187,16 +169,16 @@ static void poll_napi(struct net_device *dev)
 	}
 }
 
-static void netpoll_poll_dev(struct net_device *dev)
+void netpoll_poll_dev(struct net_device *dev)
 {
-	const struct net_device_ops *ops;
 	struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
+	const struct net_device_ops *ops;
 
 	/* 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 (down_trylock(&ni->dev_lock))
+	if (!ni || down_trylock(&ni->dev_lock))
 		return;
 
 	if (!netif_running(dev)) {
@@ -205,13 +187,8 @@ static void netpoll_poll_dev(struct net_device *dev)
 	}
 
 	ops = dev->netdev_ops;
-	if (!ops->ndo_poll_controller) {
-		up(&ni->dev_lock);
-		return;
-	}
-
-	/* Process pending work on NIC */
-	ops->ndo_poll_controller(dev);
+	if (ops->ndo_poll_controller)
+		ops->ndo_poll_controller(dev);
 
 	poll_napi(dev);
 
@@ -219,6 +196,7 @@ static void netpoll_poll_dev(struct net_device *dev)
 
 	zap_completion_queue();
 }
+EXPORT_SYMBOL(netpoll_poll_dev);
 
 void netpoll_poll_disable(struct net_device *dev)
 {
@@ -334,6 +312,7 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
 	/* It is up to the caller to keep npinfo alive. */
 	struct netpoll_info *npinfo;
 
+	rcu_read_lock_bh();
 	lockdep_assert_irqs_disabled();
 
 	npinfo = rcu_dereference_bh(np->dev->npinfo);
@@ -378,6 +357,7 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
 		skb_queue_tail(&npinfo->txq, skb);
 		schedule_delayed_work(&npinfo->tx_work,0);
 	}
+	rcu_read_unlock_bh();
 }
 EXPORT_SYMBOL(netpoll_send_skb_on_dev);
 
@@ -613,8 +593,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
 	strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
 	INIT_WORK(&np->cleanup_work, netpoll_async_cleanup);
 
-	if ((ndev->priv_flags & IFF_DISABLE_NETPOLL) ||
-	    !ndev->netdev_ops->ndo_poll_controller) {
+	if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
 		np_err(np, "%s doesn't support polling, aborting\n",
 		       np->dev_name);
 		err = -ENOTSUPP;