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

[Richard W.M. Jones]

On Wed, Aug 31, 2022 at 10:49:42PM +0800, Ming Lei wrote:
> On Wed, Aug 31, 2022 at 5:41 PM Richard W.M. Jones <rjones at redhat.com> wrote:
> >
> > On Wed, Aug 31, 2022 at 05:29:13PM +0800, Ming Lei wrote:
> > > I can reproduce it, please try the top patch in aio branch, which fixed
> > > hang in my reproducer with your test setting.
> > >
> > > https://github.com/ming1/ubdsrv/commits/aio
> >
> > (https://github.com/ming1/ubdsrv/commit/0a293b6eb7149dc5ee83e5d07d242accdb840c85)
> >
> > Yes, that seems to fix it.
> >
> > I have two loops, one git-cloning the kernel, and another copying the
> > source of nbdkit and recompiling it, and they are both working without
> > problems.
> 
> BTW, aio branch has been merged to ublksrv/master, but the interface
> of ublksrv_aio_submit_req() changed, so please sync with ublksrv.

OK I have updated nbdublk:

https://gitlab.com/rwmjones/libnbd/-/commits/nbdublk/

I have also added the changes to Fedora:

https://koji.fedoraproject.org/koji/taskinfo?taskID=91468555

Please consider becoming a Fedora packager so you can comaintain
this package.

On the subject of the kernel issue, I have been running builds and git
clones in a loop for many hours on a local (virtio-scsi) filesystem,
and I have *not* seen the kernel memory corruption problem happening.

I will go back to testing ublk again to see if the kernel memory
corruption bug is reproducible.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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