Re: [dm-devel] Re: Write barriers on MD RAID1

From: NeilBrown
Date: Wed Jun 24 2009 - 03:35:11 EST


On Wed, June 24, 2009 5:09 pm, Alasdair G Kergon wrote:
> On Wed, Jun 24, 2009 at 01:43:35PM +1000, Neil Brown wrote:
>> Since this test was added, barriers have not worked on md, and (I
>> think) dm and similar devices that don't use __make_request and so
>> don't bother to set next_ordered.
>
> In dm, we added this:
>
> + blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN, NULL);
>

I obviously didn't grep for the right thing.

This will obviously work, but I can't help thinking it is in the wrong
place. I don't even have a queue in md/raid1, so making a statement
about how it is ordered just doesn't make sense.

Jens?

NeilBrown

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/