[NET] front: Do not read features from backend until it enters InitWait.

Signed-off-by: Keir Fraser <keir@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 e4987f781d73068fe241c677fd6eba033900a1e3..55101210d20ab9c60b3652f187e0cf332c333a74 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
@@ -229,9 +229,8 @@ static inline grant_ref_t xennet_get_rx_ref(struct netfront_info *np,
 #define WPRINTK(fmt, args...)                          \
        printk(KERN_WARNING "netfront: " fmt, ##args)
 
-static int talk_to_backend(struct xenbus_device *, struct netfront_info *);
 static int setup_device(struct xenbus_device *, struct netfront_info *);
-static struct net_device *create_netdev(int, struct xenbus_device *);
+static struct net_device *create_netdev(struct xenbus_device *);
 
 static void netfront_closing(struct xenbus_device *);
 
@@ -241,7 +240,7 @@ static int open_netdev(struct netfront_info *);
 static void close_netdev(struct netfront_info *);
 static void netif_free(struct netfront_info *);
 
-static void network_connect(struct net_device *);
+static int network_connect(struct net_device *);
 static void network_tx_buf_gc(struct net_device *);
 static void network_alloc_rx_buffers(struct net_device *);
 static int send_fake_arp(struct net_device *);
@@ -264,8 +263,7 @@ static inline int xennet_can_sg(struct net_device *dev)
 /**
  * Entry point to this code when a new device is created.  Allocate the basic
  * structures and the ring buffers for communication with the backend, and
- * inform the backend of the appropriate details for those.  Switch to
- * Connected state.
+ * inform the backend of the appropriate details for those.
  */
 static int __devinit netfront_probe(struct xenbus_device *dev,
                                    const struct xenbus_device_id *id)
@@ -273,26 +271,8 @@ static int __devinit netfront_probe(struct xenbus_device *dev,
        int err;
        struct net_device *netdev;
        struct netfront_info *info;
-       unsigned int feature_rx_copy, feature_rx_flip, use_copy;
 
-       err = xenbus_scanf(XBT_NIL, dev->otherend, "feature-rx-copy", "%u",
-                          &feature_rx_copy);
-       if (err != 1)
-               feature_rx_copy = 0;
-       err = xenbus_scanf(XBT_NIL, dev->otherend, "feature-rx-flip", "%u",
-                          &feature_rx_flip);
-       if (err != 1)
-               feature_rx_flip = 1;
-
-       /*
-        * Copy packets on receive path if:
-        *  (a) This was requested by user, and the backend supports it; or
-        *  (b) Flipping was requested, but this is unsupported by the backend.
-        */
-       use_copy = (MODPARM_rx_copy && feature_rx_copy) ||
-               (MODPARM_rx_flip && !feature_rx_flip);
-
-       netdev = create_netdev(use_copy, dev);
+       netdev = create_netdev(dev);
        if (IS_ERR(netdev)) {
                err = PTR_ERR(netdev);
                xenbus_dev_fatal(dev, err, "creating netdev");
@@ -302,23 +282,13 @@ static int __devinit netfront_probe(struct xenbus_device *dev,
        info = netdev_priv(netdev);
        dev->dev.driver_data = info;
 
-       err = talk_to_backend(dev, info);
-       if (err)
-               goto fail_backend;
-
        err = open_netdev(info);
        if (err)
-               goto fail_open;
-
-       IPRINTK("Created netdev %s with %sing receive path.\n",
-               netdev->name, info->copying_receiver ? "copy" : "flipp");
+               goto fail;
 
        return 0;
 
- fail_open:
-       xennet_sysfs_delif(info->netdev);
-       unregister_netdev(netdev);
- fail_backend:
+ fail:
        free_netdev(netdev);
        dev->dev.driver_data = NULL;
        return err;
@@ -338,7 +308,7 @@ static int netfront_resume(struct xenbus_device *dev)
        DPRINTK("%s\n", dev->nodename);
 
        netif_disconnect_backend(info);
-       return talk_to_backend(dev, info);
+       return 0;
 }
 
 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
@@ -449,7 +419,7 @@ again:
        xenbus_transaction_end(xbt, 1);
        xenbus_dev_fatal(dev, err, "%s", message);
  destroy_ring:
-       netif_free(info);
+       netif_disconnect_backend(info);
  out:
        return err;
 }
@@ -539,7 +509,10 @@ static void backend_changed(struct xenbus_device *dev,
                break;
 
        case XenbusStateInitWait:
-               network_connect(netdev);
+               if (network_connect(netdev) != 0) {
+                       netif_free(np);
+                       break;
+               }
                xenbus_switch_state(dev, XenbusStateConnected);
                (void)send_fake_arp(netdev);
                break;
@@ -1644,16 +1617,41 @@ static void xennet_set_features(struct net_device *dev)
                xennet_set_tso(dev, 1);
 }
 
-static void network_connect(struct net_device *dev)
+static int network_connect(struct net_device *dev)
 {
        struct netfront_info *np = netdev_priv(dev);
-       int i, requeue_idx;
+       int i, requeue_idx, err;
        struct sk_buff *skb;
        grant_ref_t ref;
        netif_rx_request_t *req;
+       unsigned int feature_rx_copy, feature_rx_flip;
+
+       err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
+                          "feature-rx-copy", "%u", &feature_rx_copy);
+       if (err != 1)
+               feature_rx_copy = 0;
+       err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
+                          "feature-rx-flip", "%u", &feature_rx_flip);
+       if (err != 1)
+               feature_rx_flip = 1;
+
+       /*
+        * Copy packets on receive path if:
+        *  (a) This was requested by user, and the backend supports it; or
+        *  (b) Flipping was requested, but this is unsupported by the backend.
+        */
+       np->copying_receiver = ((MODPARM_rx_copy && feature_rx_copy) ||
+                               (MODPARM_rx_flip && !feature_rx_flip));
+
+       err = talk_to_backend(np->xbdev, np);
+       if (err)
+               return err;
 
        xennet_set_features(dev);
 
+       IPRINTK("device %s has %sing receive path.\n",
+               dev->name, np->copying_receiver ? "copy" : "flipp");
+
        spin_lock_irq(&np->tx_lock);
        spin_lock(&np->rx_lock);
 
@@ -1709,6 +1707,8 @@ static void network_connect(struct net_device *dev)
 
        spin_unlock(&np->rx_lock);
        spin_unlock_irq(&np->tx_lock);
+
+       return 0;
 }
 
 static void netif_uninit(struct net_device *dev)
@@ -1874,8 +1874,7 @@ static void network_set_multicast_list(struct net_device *dev)
 {
 }
 
-static struct net_device * __devinit
-create_netdev(int copying_receiver, struct xenbus_device *dev)
+static struct net_device * __devinit create_netdev(struct xenbus_device *dev)
 {
        int i, err = 0;
        struct net_device *netdev = NULL;
@@ -1890,7 +1889,6 @@ create_netdev(int copying_receiver, struct xenbus_device *dev)
 
        np                   = netdev_priv(netdev);
        np->xbdev            = dev;
-       np->copying_receiver = copying_receiver;
 
        netif_carrier_off(netdev);
 
@@ -2021,10 +2019,12 @@ static int open_netdev(struct netfront_info *info)
 
        err = xennet_sysfs_addif(info->netdev);
        if (err) {
-               /* This can be non-fatal: it only means no tuning parameters */
+               unregister_netdev(info->netdev);
                printk(KERN_WARNING "%s: add sysfs failed err=%d\n",
                       __FUNCTION__, err);
+               return err;
        }
+
        return 0;
 }