net: introduce helper dev_change_tx_queue_len()
This patch promotes the local change_tx_queue_len() to a core
helper function, dev_change_tx_queue_len(), so that rtnetlink
and net-sysfs could share the code. This also prepares for the
following patch.
Note, the -EFAULT in the original code doesn't make sense,
we should propagate the errno from notifiers.
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 858501b..520c246 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7048,6 +7048,34 @@ int dev_set_mtu(struct net_device *dev, int new_mtu)
EXPORT_SYMBOL(dev_set_mtu);
/**
+ * dev_change_tx_queue_len - Change TX queue length of a netdevice
+ * @dev: device
+ * @new_len: new tx queue length
+ */
+int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
+{
+ unsigned int orig_len = dev->tx_queue_len;
+ int res;
+
+ if (new_len != (unsigned int)new_len)
+ return -ERANGE;
+
+ if (new_len != orig_len) {
+ dev->tx_queue_len = new_len;
+ res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
+ res = notifier_to_errno(res);
+ if (res) {
+ netdev_err(dev,
+ "refused to change device tx_queue_len\n");
+ dev->tx_queue_len = orig_len;
+ return res;
+ }
+ }
+
+ return 0;
+}
+
+/**
* dev_set_group - Change group this device belongs to
* @dev: device
* @new_group: group this device should belong to