Re: [Intel-wired-lan] [PATCH iwl-net v4] ice: fix locking in ice_dcb_rebuild()

[Jacob Keller <jacob.e.keller@intel.com>]

On 4/27/2026 10:49 AM, Bart Van Assche via Intel-wired-lan wrote:
> On 3/20/26 2:28 PM, Bart Van Assche wrote:
>> Move the mutex_lock() call up to prevent that DCB settings change after
>> the first ice_query_port_ets() call. The second ice_query_port_ets()
>> call in ice_dcb_rebuild() is already protected by pf->tc_mutex.
>>
>> This also fixes a bug in an error path, as before taking the first
>> "goto dcb_error" in the function jumped over mutex_lock() to
>> mutex_unlock().
>>
>> This bug has been detected by the clang thread-safety analyzer.
>>
>> Cc: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
>> Cc: intel-wired-lan@lists.osuosl.org
>> Fixes: 242b5e068b25 ("ice: Fix DCB rebuild after reset")
>> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
>> ---
>>
>> v4 (this patch): Changed "[PATCH] iwl-net:" into "[PATCH iwl-net]".
>>
>> v3 (2026-03-20): Modified patch description. See also
>>    https://lore.kernel.org/all/20260223220102.2158611-20-
>> bart.vanassche@linux.dev/#t
>>
>> v2 (2026-02-23): Combined the two patches into one patch and
>>    increased the amount of code covered by tc_mutex. See also
>>    https://lore.kernel.org/all/20260223220102.2158611-20-
>> bart.vanassche@linux.dev/
>>
>> v1 (2025-02-06): Two patches. See also
>>    https://lore.kernel.org/all/20250206175114.1974171-16-
>> bvanassche@acm.org/
>>
>>   drivers/net/ethernet/intel/ice/ice_dcb_lib.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c b/drivers/
>> net/ethernet/intel/ice/ice_dcb_lib.c
>> index bd77f1c001ee..78ded6876581 100644
>> --- a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
>> +++ b/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
>> @@ -537,14 +537,14 @@ void ice_dcb_rebuild(struct ice_pf *pf)
>>       struct ice_dcbx_cfg *err_cfg;
>>       int ret;
>>   +    mutex_lock(&pf->tc_mutex);
>> +
>>       ret = ice_query_port_ets(pf->hw.port_info, &buf, sizeof(buf),
>> NULL);
>>       if (ret) {
>>           dev_err(dev, "Query Port ETS failed\n");
>>           goto dcb_error;
>>       }
>>   -    mutex_lock(&pf->tc_mutex);
>> -
>>       if (!pf->hw.port_info->qos_cfg.is_sw_lldp)
>>           ice_cfg_etsrec_defaults(pf->hw.port_info);
>>   
> 
> Hi Tony,
> 
> It seems like this patch has not made it into Linux kernel v7.1-rc. Do
> you agree that this patch is ready to be merged? I checked that it still
> applies to Linus' master branch.
> 
> Thanks,
> 
> Bart.

Hi Bart,

I am covering for Tony while he is on vacation. This patch only recently
completed our internal testing round. It unfortunately took a while to
complete testing due to our existing backlog of patches.

I'm preparing to include it in my next round of patches to submit to
netdev's net tree.

Thanks,
Jake