Re: [PATCH v13] blk-mq: Rework blk-mq timeout handling again

Jens Axboe
2018-05-22T21:02:12Z

On 5/22/18 3:02 PM, Christoph Hellwig wrote:
> On Tue, May 22, 2018 at 02:29:21PM -0600, Jens Axboe wrote:
>>> of BLK_EH_HANDLED. Is the driver supposed to return BLK_EH_NOT_HANDLED
>>> when the driver actually knows the request has been completed before
>>> returning the status?
>>
>> If the driver knows it's completed, it'd have to return BLK_EH_NOT_HANDLED.
>> Or BLK_EH_HANDLED would work too, since the above state transition would
>> then fail.
>
> Btw, I think we should just kill off BLK_EH_HANDLED. WIP totally
> untested progress toward that is here:
>
> http://git.infradead.org/users/hch/block.git/shortlog/refs/heads/blk-eh-ret
>
> The only real missing bit is SCSI overloading the value for internal
> use.

I think that's a great idea, the use cases aren't clear at all, driver
writers will get this wrong.

--
Jens Axboe