Commit 7effaf06 authored Jul 24, 2018 by Tariq Toukan Committed by David S. Miller Jul 26, 2018

net: rollback orig value on failure of dev_qdisc_change_tx_queue_len



Fix dev_change_tx_queue_len so it rolls back original value
upon a failure in dev_qdisc_change_tx_queue_len.
This is already done for notifirers' failures, share the code.

In case of failure in dev_qdisc_change_tx_queue_len, some tx queues
would still be of the new length, while they should be reverted.
Currently, the revert is not done, and is marked with a TODO label
in dev_qdisc_change_tx_queue_len, and should find some nice solution
to do it.
Yet it is still better to not apply the newly requested value.

Fixes: 48bfd55e ("net_sched: plug in qdisc ops change_tx_queue_len")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Reported-by: Ran Rozenstein <ranro@mellanox.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 7f3fc7dd

net/core/dev.c

+10 −7

Original line number	Diff line number	Diff line
		@@ -7149,16 +7149,19 @@ int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_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 dev_qdisc_change_tx_queue_len(dev);
		if (res)
		goto err_rollback;
		res = dev_qdisc_change_tx_queue_len(dev);
		if (res)
		goto err_rollback;
		}

		return 0;

		err_rollback:
		netdev_err(dev, "refused to change device tx_queue_len\n");
		dev->tx_queue_len = orig_len;
		return res;
		}

		/**

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