Re: [PATCH V2 2/4] net/bonding: fix non-terminable while loop

[Ferruh Yigit <ferruh.yigit@xilinx.com>]

On 4/29/2022 7:52 AM, Min Hu (Connor) wrote:
> Hi, Ferruh,
> 
> 在 2022/4/27 2:19, Ferruh Yigit 写道:
>> On 3/24/2022 3:00 AM, Min Hu (Connor) wrote:
>>> From: Huisong Li <lihuisong@huawei.com>
>>>
>>> All slaves will be stopped and removed when closing a bonded port. 
>>> But the
>>> while loop can not stop if both rte_eth_dev_stop and
>>> rte_eth_bond_slave_remove fail to run.
>>>
>>
>> Agree that this is a defect introduced in below commit. Thanks for the 
>> fix.
> thanks.
>>
>>> Fixes: fb0379bc5db3 ("net/bonding: check stop call status")
>>> Cc: stable@dpdk.org
>>>
>>> Signed-off-by: Huisong Li <lihuisong@huawei.com>
>>> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
>>> ---
>>>   drivers/net/bonding/rte_eth_bond_pmd.c | 3 ++-
>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/bonding/rte_eth_bond_pmd.c 
>>> b/drivers/net/bonding/rte_eth_bond_pmd.c
>>> index 469dc71170..00d4deda44 100644
>>> --- a/drivers/net/bonding/rte_eth_bond_pmd.c
>>> +++ b/drivers/net/bonding/rte_eth_bond_pmd.c
>>> @@ -2149,13 +2149,14 @@ bond_ethdev_close(struct rte_eth_dev *dev)
>>>           return 0;
>>>       RTE_BOND_LOG(INFO, "Closing bonded device %s", dev->device->name);
>>> -    while (internals->slave_count != skipped) {
>>> +    while (skipped < internals->slave_count) {
>>
>> When below fixed with adding 'continue', no need to change the check, 
>> right? Although new one is also correct.
> Agreed.
>>
>>>           uint16_t port_id = internals->slaves[skipped].port_id;
>>>           if (rte_eth_dev_stop(port_id) != 0) {
>>>               RTE_BOND_LOG(ERR, "Failed to stop device on port %u",
>>>                        port_id);
>>>               skipped++;
>>> +            continue;
>>
>> Can't we remove the slave even if 'stop()' failed? If so I think 
>> better to just log the error and keep continue in that case, what do 
>> you think?
> NO, if slave stop failed, we cannot remove the slave.

Got it, thanks for clarification.

> just see the function stack:
> rte_eth_bond_slave_remove
> __eth_bond_slave_remove_lock_free
> slave_remove
> rte_eth_dev_internal_reset
> if (dev->data->dev_started) {
>      RTE_ETHDEV_LOG(ERR, "Port %u must be stopped to allow reset\n",
>          dev->data->port_id);
>      return;
> }
> 
>>
>>>           }
>>>           if (rte_eth_bond_slave_remove(bond_port_id, port_id) != 0) {
>>
>> .