From: shand@chelmsford.uk.xensource.com <shand@chelmsford.uk.xensource.com>
Date: Mon, 12 Jun 2006 16:56:20 +0000 (+0100)
Subject: Fix race in device resume path - need to ensure we add the watch only
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~15972^2~7
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=9f640de2b067a6b299b941941b4b6de7c33d2715;p=xen.git

Fix race in device resume path - need to ensure we add the watch only
after the device-specific resume code has run. Also removed some unused /
usless code from netfront.c.

Signed-off-by: Steven Hand <steven@xensource.com>
---

diff --git a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
index 6a026774d4..b0fc28d04c 100644
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
@@ -157,8 +157,6 @@ static void netif_disconnect_backend(struct netfront_info *);
 static void close_netdev(struct netfront_info *);
 static void netif_free(struct netfront_info *);
 
-static void show_device(struct netfront_info *);
-
 static void network_connect(struct net_device *);
 static void network_tx_buf_gc(struct net_device *);
 static void network_alloc_rx_buffers(struct net_device *);
@@ -411,7 +409,6 @@ static void backend_changed(struct xenbus_device *dev,
 		network_connect(netdev);
 		xenbus_switch_state(dev, XenbusStateConnected);
 		(void)send_fake_arp(netdev);
-		show_device(np);
 		break;
 
 	case XenbusStateClosing:
@@ -605,7 +602,7 @@ static void network_alloc_rx_buffers(struct net_device *dev)
 		np->grant_rx_ref[id] = ref;
 		gnttab_grant_foreign_transfer_ref(ref,
 						  np->xbdev->otherend_id,
-						  __pa(skb->head) >> PAGE_SHIFT);
+						  __pa(skb->head)>>PAGE_SHIFT);
 		RING_GET_REQUEST(&np->rx, req_prod + i)->gref = ref;
 		np->rx_pfn_array[i] = virt_to_mfn(skb->head);
 
@@ -1166,22 +1163,6 @@ static void network_connect(struct net_device *dev)
 	spin_unlock_irq(&np->tx_lock);
 }
 
-static void show_device(struct netfront_info *np)
-{
-#ifdef DEBUG
-	if (np) {
-		IPRINTK("<vif handle=%u %s(%s) evtchn=%u tx=%p rx=%p>\n",
-			np->handle,
-			netif_carrier_ok(np->netdev) ? "on" : "off",
-			netif_running(np->netdev) ? "open" : "closed",
-			np->evtchn,
-			np->tx,
-			np->rx);
-	} else
-		IPRINTK("<vif NULL>\n");
-#endif
-}
-
 static void netif_uninit(struct net_device *dev)
 {
 	struct netfront_info *np = netdev_priv(dev);
diff --git a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c
index b03957e983..3bef9b3084 100644
--- a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c
+++ b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c
@@ -806,6 +806,7 @@ static int resume_dev(struct device *dev, void *data)
 
 	if (dev->driver == NULL)
 		return 0;
+
 	drv = to_xenbus_driver(dev->driver);
 	xdev = container_of(dev, struct xenbus_device, dev);
 
@@ -816,6 +817,18 @@ static int resume_dev(struct device *dev, void *data)
 		       dev->bus_id, err);
 		return err;
 	}
+        
+	xdev->state = XenbusStateInitialising;
+        
+	if (drv->resume) {
+		err = drv->resume(xdev);
+                if (err) { 
+                        printk(KERN_WARNING
+                               "xenbus: resume %s failed: %i\n", 
+                               dev->bus_id, err);
+                        return err; 
+                }
+        }
 
 	err = watch_otherend(xdev);
 	if (err) {
@@ -825,14 +838,7 @@ static int resume_dev(struct device *dev, void *data)
 		return err;
 	}
 
-	xdev->state = XenbusStateInitialising;
-
-	if (drv->resume)
-		err = drv->resume(xdev);
-	if (err)
-		printk(KERN_WARNING
-		       "xenbus: resume %s failed: %i\n", dev->bus_id, err);
-	return err;
+	return 0; 
 }
 
 void xenbus_suspend(void)