Re: [PATCH] qla2xxx: Fix dpc_thread race on the module unload

[Vladislav Bolkhovitin <vst@vlnb.net>]

James Bottomley wrote:
> On Mon, 2008-07-28 at 21:33 +0400, Vladislav Bolkhovitin wrote:
>> This patch fixes race on dpc_thread field of struct scsi_qla_host,
>> which can lead to crash on the module unload.
>>
>> This patch is against 2.6.26
> 
> I'm afraid adding a lock is almost certainly the wrong way to handle
> this type of failure. 

Why? It's simple and fully solves the problem. All the events, which 
left unhandled, because there is nobody to wake up by 
qla2xxx_wake_dpc(), are not relevant after the driver's shutdown.

> What should be done is to make sure the qla is
> correctly shut down (i.e. no tasks requiring the dpc_thread can be
> performed) *before* killing the thread ...

Sure, in ideal it would be the best approach. But, certainly, it would 
be a lot more complicated and error-prone.

 From other side, actually, it doesn't matter much for me how it will be 
fixed, if it's fixed.

> it sounds like shutdown is
> slightly broken in the current driver ... could you post the oops
> details and we can try to work out what the problem is

Gal, can you send the details, please?

> James
> 
> 
>