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

On Mon, Aug 30 2010 at 11:07am -0400,
Tejun Heo [off-list ref] wrote:

On 08/30/2010 03:59 PM, Tejun Heo wrote:

quoted

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 <redacted>