From 7effaf06c3cdef6855e127886c7405b9ab62f90d Mon Sep 17 00:00:00 2001 From: Tariq Toukan Date: Tue, 24 Jul 2018 14:12:20 +0300 Subject: [PATCH] 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: 48bfd55e7e41 ("net_sched: plug in qdisc ops change_tx_queue_len") Signed-off-by: Tariq Toukan Reviewed-by: Eran Ben Elisha Reported-by: Ran Rozenstein Cc: Cong Wang Signed-off-by: David S. Miller --- net/core/dev.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index a5aa1c7444e6..559a91271f82 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -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; } /**