Re: [PATCH V3 7/8] block: allow to allocate req with REQF_PREEMPT when queue is preempt frozen

Ming Lei
2017-09-09T07:21:29Z

On Fri, Sep 08, 2017 at 05:28:16PM +0000, Bart Van Assche wrote:
> On Fri, 2017-09-08 at 11:08 +0800, Ming Lei wrote:
> > Looks I replied or clarified all your questions/comments on this
> > patchset.
>
> No, you have not addressed all my comments, you know that you have not
> addressed all my comments so you should not have written that you have

I do not know.

> addressed all my comments. This patch series not only introduces ugly
> changes in the request queue freeze mechanism but it also introduces an
> unacceptable race condition between blk_get_request() and request queue
> cleanup.

So what is the race? Could you reply in original thread?

>
> BTW, you don't have to spend more time on this patch series. I have
> implemented an alternative and much cleaner approach to fix SCSI device
> suspend. I'm currently testing that patch series.

You do not understand the issue at all, it is not only related with
suspend. Please take a look at scsi_execute(), each request run
via scsi_execute() need to be dispatched successfully even when
SCSI device is quiesced.

--
Ming