on 2020/02/19 23:20, Theodore Y. Ts'o wrote:
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?
Of course, I will update lastest qemu to test.(I don't have their support).
- Ted
