1 files changed, 81 insertions, 52 deletions

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index d6abf191122a..0a4bd73caae5 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -86,6 +86,8 @@ struct netfront_cb {
 /* IRQ name is queue name with "-tx" or "-rx" appended */
 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
 
+static DECLARE_WAIT_QUEUE_HEAD(module_wq);
+
 struct netfront_stats {
 	u64			packets;
 	u64			bytes;
@@ -236,7 +238,7 @@ static void rx_refill_timeout(unsigned long data)
 static int netfront_tx_slot_available(struct netfront_queue *queue)
 {
 	return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
-		(NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
+		(NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
 }
 
 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
@@ -304,7 +306,7 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 		queue->rx_skbs[id] = skb;
 
 		ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
-		BUG_ON((signed short)ref < 0);
+		WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
 		queue->grant_rx_ref[id] = ref;
 
 		page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
@@ -321,7 +323,7 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
 	queue->rx.req_prod_pvt = req_prod;
 
 	/* Not enough requests? Try again later. */
-	if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN) {
+	if (req_prod - queue->rx.sring->req_prod < NET_RX_SLOTS_MIN) {
 		mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
 		return;
 	}
@@ -340,6 +342,9 @@ static int xennet_open(struct net_device *dev)
 	unsigned int i = 0;
 	struct netfront_queue *queue = NULL;
 
+	if (!np->queues)
+		return -ENODEV;
+
 	for (i = 0; i < num_queues; ++i) {
 		queue = &np->queues[i];
 		napi_enable(&queue->napi);
@@ -437,7 +442,7 @@ static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
 	id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
 	tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
 	ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
-	BUG_ON((signed short)ref < 0);
+	WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
 
 	gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
 					gfn, GNTMAP_readonly);
@@ -770,7 +775,7 @@ static int xennet_get_responses(struct netfront_queue *queue,
 	RING_IDX cons = queue->rx.rsp_cons;
 	struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
 	grant_ref_t ref = xennet_get_rx_ref(queue, cons);
-	int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
+	int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
 	int slots = 1;
 	int err = 0;
 	unsigned long ret;
@@ -873,7 +878,6 @@ static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
 				  struct sk_buff *skb,
 				  struct sk_buff_head *list)
 {
-	struct skb_shared_info *shinfo = skb_shinfo(skb);
 	RING_IDX cons = queue->rx.rsp_cons;
 	struct sk_buff *nskb;
 
@@ -882,15 +886,20 @@ static RING_IDX xennet_fill_frags(struct netfront_queue *queue,
 			RING_GET_RESPONSE(&queue->rx, ++cons);
 		skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
 
-		if (shinfo->nr_frags == MAX_SKB_FRAGS) {
+		if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
 			unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
 
 			BUG_ON(pull_to <= skb_headlen(skb));
 			__pskb_pull_tail(skb, pull_to - skb_headlen(skb));
 		}
-		BUG_ON(shinfo->nr_frags >= MAX_SKB_FRAGS);
+		if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
+			queue->rx.rsp_cons = ++cons;
+			kfree_skb(nskb);
+			return ~0U;
+		}
 
-		skb_add_rx_frag(skb, shinfo->nr_frags, skb_frag_page(nfrag),
+		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
+				skb_frag_page(nfrag),
 				rx->offset, rx->status, PAGE_SIZE);
 
 		skb_shinfo(nskb)->nr_frags = 0;
@@ -1024,6 +1033,8 @@ err:
 		skb->len += rx->status;
 
 		i = xennet_fill_frags(queue, skb, &tmpq);
+		if (unlikely(i == ~0U))
+			goto err;
 
 		if (rx->flags & XEN_NETRXF_csum_blank)
 			skb->ip_summed = CHECKSUM_PARTIAL;
@@ -1329,6 +1340,12 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev)
 
 	netif_carrier_off(netdev);
 
+	xenbus_switch_state(dev, XenbusStateInitialising);
+	wait_event(module_wq,
+		   xenbus_read_driver_state(dev->otherend) !=
+		   XenbusStateClosed &&
+		   xenbus_read_driver_state(dev->otherend) !=
+		   XenbusStateUnknown);
 	return netdev;
 
  exit:
@@ -1360,18 +1377,8 @@ static int netfront_probe(struct xenbus_device *dev,
 #ifdef CONFIG_SYSFS
 	info->netdev->sysfs_groups[0] = &xennet_dev_group;
 #endif
-	err = register_netdev(info->netdev);
-	if (err) {
-		pr_warn("%s: register_netdev err=%d\n", __func__, err);
-		goto fail;
-	}
 
 	return 0;
-
- fail:
-	xennet_free_netdev(netdev);
-	dev_set_drvdata(&dev->dev, NULL);
-	return err;
 }
 
 static void xennet_end_access(int ref, void *page)
@@ -1391,6 +1398,8 @@ static void xennet_disconnect_backend(struct netfront_info *info)
 	for (i = 0; i < num_queues && info->queues; ++i) {
 		struct netfront_queue *queue = &info->queues[i];
 
+		del_timer_sync(&queue->rx_refill_timer);
+
 		if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
 			unbind_from_irqhandler(queue->tx_irq, queue);
 		if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
@@ -1604,6 +1613,7 @@ static int xennet_init_queue(struct netfront_queue *queue)
 {
 	unsigned short i;
 	int err = 0;
+	char *devid;
 
 	spin_lock_init(&queue->tx_lock);
 	spin_lock_init(&queue->rx_lock);
@@ -1611,8 +1621,9 @@ static int xennet_init_queue(struct netfront_queue *queue)
 	setup_timer(&queue->rx_refill_timer, rx_refill_timeout,
 		    (unsigned long)queue);
 
-	snprintf(queue->name, sizeof(queue->name), "%s-q%u",
-		 queue->info->netdev->name, queue->id);
+	devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
+	snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
+		 devid, queue->id);
 
 	/* Initialise tx_skbs as a free chain containing every entry. */
 	queue->tx_skb_freelist = 0;
@@ -1738,19 +1749,14 @@ static void xennet_destroy_queues(struct netfront_info *info)
 {
 	unsigned int i;
 
-	rtnl_lock();
-
 	for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
 		struct netfront_queue *queue = &info->queues[i];
 
 		if (netif_running(info->netdev))
 			napi_disable(&queue->napi);
-		del_timer_sync(&queue->rx_refill_timer);
 		netif_napi_del(&queue->napi);
 	}
 
-	rtnl_unlock();
-
 	kfree(info->queues);
 	info->queues = NULL;
 }
@@ -1766,8 +1772,6 @@ static int xennet_create_queues(struct netfront_info *info,
 	if (!info->queues)
 		return -ENOMEM;
 
-	rtnl_lock();
-
 	for (i = 0; i < *num_queues; i++) {
 		struct netfront_queue *queue = &info->queues[i];
 
@@ -1776,7 +1780,7 @@ static int xennet_create_queues(struct netfront_info *info,
 
 		ret = xennet_init_queue(queue);
 		if (ret < 0) {
-			dev_warn(&info->netdev->dev,
+			dev_warn(&info->xbdev->dev,
 				 "only created %d queues\n", i);
 			*num_queues = i;
 			break;
@@ -1790,10 +1794,8 @@ static int xennet_create_queues(struct netfront_info *info,
 
 	netif_set_real_num_tx_queues(info->netdev, *num_queues);
 
-	rtnl_unlock();
-
 	if (*num_queues == 0) {
-		dev_err(&info->netdev->dev, "no queues\n");
+		dev_err(&info->xbdev->dev, "no queues\n");
 		return -EINVAL;
 	}
 	return 0;
@@ -1835,31 +1837,25 @@ static int talk_to_netback(struct xenbus_device *dev,
 		goto out;
 	}
 
+	rtnl_lock();
 	if (info->queues)
 		xennet_destroy_queues(info);
 
 	err = xennet_create_queues(info, &num_queues);
-	if (err < 0)
-		goto destroy_ring;
+	if (err < 0) {
+		xenbus_dev_fatal(dev, err, "creating queues");
+		kfree(info->queues);
+		info->queues = NULL;
+		goto out;
+	}
+	rtnl_unlock();
 
 	/* Create shared ring, alloc event channel -- for each queue */
 	for (i = 0; i < num_queues; ++i) {
 		queue = &info->queues[i];
 		err = setup_netfront(dev, queue, feature_split_evtchn);
-		if (err) {
-			/* setup_netfront() will tidy up the current
-			 * queue on error, but we need to clean up
-			 * those already allocated.
-			 */
-			if (i > 0) {
-				rtnl_lock();
-				netif_set_real_num_tx_queues(info->netdev, i);
-				rtnl_unlock();
-				goto destroy_ring;
-			} else {
-				goto out;
-			}
-		}
+		if (err)
+			goto destroy_ring;
 	}
 
 again:
@@ -1949,9 +1945,11 @@ abort_transaction_no_dev_fatal:
 	xenbus_transaction_end(xbt, 1);
  destroy_ring:
 	xennet_disconnect_backend(info);
-	kfree(info->queues);
-	info->queues = NULL;
+	rtnl_lock();
+	xennet_destroy_queues(info);
  out:
+	rtnl_unlock();
+	device_unregister(&dev->dev);
 	return err;
 }
 
@@ -1986,6 +1984,15 @@ static int xennet_connect(struct net_device *dev)
 	netdev_update_features(dev);
 	rtnl_unlock();
 
+	if (dev->reg_state == NETREG_UNINITIALIZED) {
+		err = register_netdev(dev);
+		if (err) {
+			pr_warn("%s: register_netdev err=%d\n", __func__, err);
+			device_unregister(&np->xbdev->dev);
+			return err;
+		}
+	}
+
 	/*
 	 * All public and private state should now be sane.  Get
 	 * ready to start sending and receiving packets and give the driver
@@ -2023,6 +2030,8 @@ static void netback_changed(struct xenbus_device *dev,
 
 	dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
 
+	wake_up_all(&module_wq);
+
 	switch (backend_state) {
 	case XenbusStateInitialising:
 	case XenbusStateInitialised:
@@ -2153,12 +2162,32 @@ static int xennet_remove(struct xenbus_device *dev)
 
 	dev_dbg(&dev->dev, "%s\n", dev->nodename);
 
+	if (xenbus_read_driver_state(dev->otherend) != XenbusStateClosed) {
+		xenbus_switch_state(dev, XenbusStateClosing);
+		wait_event(module_wq,
+			   xenbus_read_driver_state(dev->otherend) ==
+			   XenbusStateClosing ||
+			   xenbus_read_driver_state(dev->otherend) ==
+			   XenbusStateUnknown);
+
+		xenbus_switch_state(dev, XenbusStateClosed);
+		wait_event(module_wq,
+			   xenbus_read_driver_state(dev->otherend) ==
+			   XenbusStateClosed ||
+			   xenbus_read_driver_state(dev->otherend) ==
+			   XenbusStateUnknown);
+	}
+
 	xennet_disconnect_backend(info);
 
-	unregister_netdev(info->netdev);
+	if (info->netdev->reg_state == NETREG_REGISTERED)
+		unregister_netdev(info->netdev);
 
-	if (info->queues)
+	if (info->queues) {
+		rtnl_lock();
 		xennet_destroy_queues(info);
+		rtnl_unlock();
+	}
 	xennet_free_netdev(info->netdev);
 
 	return 0;