On Wed, Feb 19, 2020 at 01:43:24PM +0100, Jan Kara wrote:
> This means, fsstress command has queued cache flush request (from
> blkdev_issue_flush()), this has been dispatched to the driver ('D' event)
> but it has never been completed by the driver and so blkdev_issue_flush()
> never returns.
>
> To debug this further, you probably need to start looking into what happens
> with the request inside QEMU. There's not much I can help you with at this
> point since I'm not an expert there. Do you use image file as a backing store
> or a raw partition?
This is looking more and more like a Qemu bug or a host OS issue.
Yang is using a two year old Qemu (qemu-kvm-2.12.0-32.el8+1900+70997154)
and is using a QCOW backing file. It also could be a host kernel bug,
although that's less likely.
Yang, any chance you could have a chance to upgrade to a newer version
of Qemu, and see if the problem goes away? If you have a RHEL support
contract, perhaps you could file a support request with the Red Hat help desk?
- Ted
