Re: [BUG] Loopback devices with 4k logical block size are not automatically scanned for GPT partitions

From: Ming Lei
Date: Thu Aug 09 2018 - 04:10:52 EST

On Thu, Aug 9, 2018 at 7:30 AM, Andrew Jeddeloh
<andrew.jeddeloh@xxxxxxxxxx> wrote:
> I think I found a bug with partition scanning/loopback devices with 4k
> logical sectors. It affects 4.14.x and 4.17.x kernels (and presumably
> others). I've also filed the bug on the kernel bugzilla:
> Copied from the bugzilla report:
> Loop devices with the logical sector size set to 4096 do not
> autodetect partitions when attached. It may be the case for devices
> with 4k logical sectors in general, but I do not have hardware to test
> that. I have not tested with non-GPT disks.

You may setup 4k sector-size with scsi_debug or qemu virtio-scsi,
then try to reproduce on these devices.

Cc block list.

Ming Lei