Re: [PATCH] xen-blkfront: save uncompleted reqs in blkfront_resume()

From: Konrad Rzeszutek Wilk
Date: Tue Jun 28 2016 - 15:54:59 EST


On Mon, Jun 27, 2016 at 04:33:24PM +0800, Bob Liu wrote:
> Uncompleted reqs used to be 'saved and resubmitted' in blkfront_recover() during
> migration, but that's too later after multi-queue introduced.
>
> After a migrate to another host (which may not have multiqueue support), the
> number of rings (block hardware queues) may be changed and the ring and shadow
> structure will also be reallocated.
> So that blkfront_recover() can't 'save and resubmit' the real uncompleted reqs
> because shadow structure has been reallocated.
>
> This patch fixes this issue by moving the 'save and resubmit' logic out of
> blkfront_recover() to earlier place:blkfront_resume().
>
> Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx>

Ack-ed and Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

Let me run it through some tests and if no regressions found I will
ask Jens to pull it.