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;