Re: [EXT] [PATCH 4/8] qla2xxx: Fix driver unload hang

Himanshu Madhani
2019-11-08T23:38:49Z

Hi Bart,

> On Nov 7, 2019, at 12:30 PM, Bart Van Assche <bvanassche@acm.org> wrote:
>
> External Email
>
> ----------------------------------------------------------------------
> On 11/7/19 9:58 AM, Bart Van Assche wrote:
>> Does your answer mean that this hang has not yet been root-caused fully
>> and hence that it is possible this patch is only a workaround but not a
>> fix of the root cause?
>
> Answering my own question: I think that a qpair refcount leak is a severe problem and not something that should be ignored. How about changing the while loop into something like the following:
>
> if (atomic_read(&qpair->ref_count))
> msleep(500);
> WARN_ON_ONCE(atomic_read(&qpair->ref_count));
>
> Thanks,
>
> Bart.

Since we had seen this hang in a specific cluster environment and refcount leak was observed, I would like to add this patch as is and will consider your suggestion to verify if adding WARN_ON_ONCE will make any difference. If we discover that adding WARN_ON_ONCE indeed helps, then I will add a patch with fixes tag during rc window.

Let me know if you disagree.

Thanks,
Himanshu