[Libguestfs] [PATCH libnbd] ublk: Add new nbdublk program

[Ming Lei]

On Wed, Aug 31, 2022 at 11:22:04AM +0100, Richard W.M. Jones wrote:
> 
> After running those tests for an hour or two I got a nasty kernel
> memory corruption issue in the test VM, see attached.

>From the dmesg log, the direct issue is from zram.

The userspace ublksrv shouldn't trigger this kind of issue, and the only
related code is to discard IO pages if they are idle for enough time via
madvise(MADV_DONTNEED).

In the ublk driver side, we just pin and unpin pages, and it shouldn't
be hard to verify if they work correctly . I will trace in that area.
Except for pin & unpin pages, ublk driver doesn't play any other mm
game.

thanks,
Ming