[PATCH 3.16 166/366] xen-netfront: Use static attribute groups for sysfs entries

Ben Hutchings
2018-11-12T05:48:10Z

From: Takashi Iwai <tiwai@suse.de>

commit 27b917e54bed7156c2b0249969ace34a5f585626 upstream.

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>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/net/xen-netfront.c | 62 ++++++++++----------------------------
1 file changed, 16 insertions(+), 46 deletions(-)

--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -228,11 +228,7 @@ static grant_ref_t xennet_get_rx_ref(str
}

#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)
@@ -1399,20 +1395,15 @@ static int netfront_probe(struct xenbus_

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:
@@ -2278,39 +2269,20 @@ static ssize_t show_rxbuf_cur(struct dev
return sprintf(buf, "0\n");
}

-static struct device_attribute xennet_attrs[] = {
- __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
- __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
- __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
+static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min);
+static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max);
+static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL);
+
+static struct attribute *xennet_dev_attrs[] = {
+ &dev_attr_rxbuf_min.attr,
+ &dev_attr_rxbuf_max.attr,
+ &dev_attr_rxbuf_cur.attr,
+ 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 const struct attribute_group xennet_dev_group = {
+ .attrs = xennet_dev_attrs
+};
#endif /* CONFIG_SYSFS */

static const struct xenbus_device_id netfront_ids[] = {
@@ -2328,8 +2300,6 @@ static int xennet_remove(struct xenbus_d

xennet_disconnect_backend(info);

- xennet_sysfs_delif(info->netdev);
-
unregister_netdev(info->netdev);

if (num_queues) {