xen-netfront: Use static attribute groups for sysfs entries

Instead of manual calls of device_create_file() and
device_remove_files(), assign the static attribute groups to netdev
groups array.  This simplifies the code and avoids the possible
races.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 46 deletions

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 7cfa6c027c0c..e9b960f0ff32 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -219,11 +219,7 @@ static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
 }
 
 #ifdef CONFIG_SYSFS
-static int xennet_sysfs_addif(struct net_device *netdev);
-static void xennet_sysfs_delif(struct net_device *netdev);
-#else /* !CONFIG_SYSFS */
-#define xennet_sysfs_addif(dev) (0)
-#define xennet_sysfs_delif(dev) do { } while (0)
+static const struct attribute_group xennet_dev_group;
 #endif
 
 static bool xennet_can_sg(struct net_device *dev)
@@ -1317,20 +1313,15 @@ static int netfront_probe(struct xenbus_device *dev,
 
         info = netdev_priv(netdev);
         dev_set_drvdata(&dev->dev, info);
-
+#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;
         }
 
-        err = xennet_sysfs_addif(info->netdev);
-        if (err) {
-                unregister_netdev(info->netdev);
-                pr_warn("%s: add sysfs failed err=%d\n", __func__, err);
-                goto fail;
-        }
-
         return 0;
 
  fail:
@@ -2094,39 +2085,20 @@ static ssize_t store_rxbuf(struct device *dev,
         return len;
 }
 
-static struct device_attribute xennet_attrs[] = {
-        __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
-        __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
-        __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL),
-};
+static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
+static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
+static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
 
-static int xennet_sysfs_addif(struct net_device *netdev)
-{
-        int i;
-        int err;
-
-        for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++) {
-                err = device_create_file(&netdev->dev,
-                                           &xennet_attrs[i]);
-                if (err)
-                        goto fail;
-        }
-        return 0;
-
- fail:
-        while (--i >= 0)
-                device_remove_file(&netdev->dev, &xennet_attrs[i]);
-        return err;
-}
-
-static void xennet_sysfs_delif(struct net_device *netdev)
-{
-        int i;
-
-        for (i = 0; i < ARRAY_SIZE(xennet_attrs); i++)
-                device_remove_file(&netdev->dev, &xennet_attrs[i]);
-}
+static struct attribute *xennet_dev_attrs[] = {
+        &dev_attr_rxbuf_min.attr,
+        &dev_attr_rxbuf_max.attr,
+        &dev_attr_rxbuf_cur.attr,
+        NULL
+};
 
+static const struct attribute_group xennet_dev_group = {
+        .attrs = xennet_dev_attrs
+};
 #endif /* CONFIG_SYSFS */
 
 static int xennet_remove(struct xenbus_device *dev)
@@ -2140,8 +2112,6 @@ static int xennet_remove(struct xenbus_device *dev)
 
         xennet_disconnect_backend(info);
 
-        xennet_sysfs_delif(info->netdev);
-
         unregister_netdev(info->netdev);
 
         for (i = 0; i < num_queues; ++i) {