Re: BUG - raid 1 deadlock on handle_read_error / wait_barrier

[Tregaron Bayly <tbayly@bluehost.com>]

On Fri, 2013-02-22 at 19:52 +0800, majianpeng wrote:

> > Feb 20 17:47:35 sanclient kernel: [4946b55d-bb0a-7fce-54c8-ac90615dabc1] Attempting to freeze array: barrier (1), nr_waiting (1), nr_pending (5), nr_queued (3)
> > Feb 20 17:47:35 sanclient kernel: [4946b55d-bb0a-7fce-54c8-ac90615dabc1] Awaiting barrier: barrier (1), nr_waiting (2), nr_pending (5), nr_queued (3)
> > Feb 20 17:47:38 sanclient kernel: [4946b55d-bb0a-7fce-54c8-ac90615dabc1] Awaiting barrier: barrier (1), nr_waiting (3), nr_pending (5), nr_queued (3)
> From those message,there's a request which will be completed or met error.
> If completed, the ->nr_pening decrease one.
> If request met error, it add ->retry_list and the ->nr_queued add one.
> So in two conditions,the hung will be happened.
> What's the state of this request? Maybe this bug caused by lower layer drivers.

That's a good question.  Do you have any suggestion as to how I might
answer it?  As I say, I can readily reproduce it so if you have some
insight into how to capture that info I can do it with no problem.

Also, I don't know for sure but it didn't sound like Joe Lawrence is
using the same lower layer drivers but he has the same problem.

Tregaron