Re: [PATCH V2 1/3] blk-mq: refactor the code of issue request directly

From: jianchao.wang
Date: Mon Oct 29 2018 - 01:41:28 EST


Hi Ming

On 10/29/18 10:49 AM, Ming Lei wrote:
> On Sat, Oct 27, 2018 at 12:01:09AM +0800, Jianchao Wang wrote:
>> Merge blk_mq_try_issue_directly and __blk_mq_try_issue_directly
>> into one interface which is able to handle the return value from
>> .queue_rq callback. Due to we can only issue directly w/o io
>> scheduler, so remove the blk_mq_get_driver_tag.
>
> It isn't correct for dm-rq, see blk_insert_cloned_request().
>

Yes, got it.
when the original requests are issued to the underlying paths as cloned
requests, they should not pass through the io scheduler.

Thanks
Jianchao