2016-12-23 12:45 GMT+01:00 Lars Ellenberg [off-list ref]:

On Fri, Dec 23, 2016 at 09:49:53AM +0100, Michael Wang wrote:

quoted

Dear Maintainers

I'd like to ask for the status of this patch since we hit the
issue too during our testing on md raid1.

Split remainder bio_A was queued ahead, following by bio_B for
lower device, at this moment raid start freezing, the loop take
out bio_A firstly and deliver it, which will hung since raid is
freezing, while the freezing never end since it waiting for
bio_B to finish, and bio_B is still on the queue, waiting for
bio_A to finish...

We're looking for a good solution and we found this patch
already progressed a lot, but we can't find it on linux-next,
so we'd like to ask are we still planning to have this fix
in upstream?

I don't see why not, I'd even like to have it in older kernels,
but did not have the time and energy to push it.

Thanks for the bump.

        Lars

Hi folks,

As Michael mentioned, we hit a bug this patch is trying to fix.
Neil suggested another way to fix it.  I attached below.
I personal prefer Neil's version as it's less code change, and straight forward.

Could you share your comments, we can get one fix into mainline.

Thanks,
Jinpu