4.17-stable review patch. If anyone has any objections, please let me know.
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From: Tariq Toukan tariqt@mellanox.com
[ Upstream commit 7effaf06c3cdef6855e127886c7405b9ab62f90d ]
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: 48bfd55e7e41 ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/dev.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)
--- a/net/core/dev.c +++ b/net/core/dev.c @@ -7113,16 +7113,19 @@ int dev_change_tx_queue_len(struct net_d 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; }
/**