Re: [dm-devel] [PATCH 4/5] dm: implement REQ_FLUSH/FUA support for request-based dm

[Mike Snitzer <snitzer redhat com>]

On Mon, Aug 30 2010 at 11:07am -0400,
Tejun Heo <tj kernel org> wrote:

> On 08/30/2010 03:59 PM, Tejun Heo wrote:
> > Ah... that's probably from "if (!elv_queue_empty(q))" check below,
> > flushes are on a separate queue but I forgot to update
> > elv_queue_empty() to check the flush queue.  elv_queue_empty() can
> > return %true spuriously in which case the queue won't be plugged and
> > restarted later leading to queue hang.  I'll fix elv_queue_empty().
> 
> I think I was too quick to blame elv_queue_empty().  Can you please
> test whether the following patch fixes the hang?

It does, thanks!

Tested-by: Mike Snitzer <snitzer redhat com>