[Libguestfs] failure to virt-sysprep (FC27?)

[Yaniv Kaul]

On Tue, Dec 12, 2017 at 2:13 PM, Richard W.M. Jones <rjones at redhat.com>
wrote:

> On Thu, Nov 23, 2017 at 02:05:32PM +0000, Richard W.M. Jones wrote:
> > On Thu, Nov 23, 2017 at 03:00:45PM +0200, Yaniv Kaul wrote:
> > > On Thu, Nov 23, 2017 at 10:57 AM, Richard W.M. Jones <
> rjones at redhat.com>
> > > wrote:
> > >
> > > > On Tue, Nov 21, 2017 at 11:43:54PM +0200, Yaniv Kaul wrote:
> > > > > Since I upgrading to FC27, I *sometimes* fail to virt-sysprep.
> > > > > The debug messages:
> > > > > libguestfs: trace: set_verbose true
> > > > > libguestfs: trace: set_verbose = 0
> > > > > libguestfs: create: flags = 0, handle = 0x7f4600005dd0, program =
> python2
> > > > > libguestfs: trace: set_program "lago"
> > > > > libguestfs: trace: set_program = 0
> > > > > libguestfs: trace: add_drive_ro
> > > > > "/home/ykaul/ovirt-system-tests/deployment-basic-suite-
> > > > master/default/images/lago-basic-suite-master-host-0_root.qcow2"
> > > > > libguestfs: trace: add_drive
> > > > > "/home/ykaul/ovirt-system-tests/deployment-basic-suite-
> > > > master/default/images/lago-basic-suite-master-host-0_root.qcow2"
> > > > > "readonly:true"
> > > > > libguestfs: creating COW overlay to protect original drive content
> > > > > libguestfs: trace: disk_format
> > > > > "/home/ykaul/ovirt-system-tests/deployment-basic-suite-
> > > > master/default/images/lago-basic-suite-master-host-0_root.qcow2"
> > > > > libguestfs: command: run: qemu-img
> > > > > libguestfs: command: run: \ info
> > > > > libguestfs: command: run: \ --output json
> > > > > libguestfs: command: run: \ /dev/fd/7
> > > > > qemu-img: Could not open '/dev/fd/7': Failed to get shared "write"
> lock
> > > > > Is another process using the image?
> >
> > Looking at this a bit closer, I think this may be a bug in qemu.
> >
> > /dev/fd/7 is supposed to be the file descriptor of the image which we
> > have opened in libguestfs, see this code:
> >
> >   https://github.com/libguestfs/libguestfs/blob/
> 06df910491c49360c0292c7153ba5e5cd09a4735/lib/info.c#L174-L191
> >
> > I wonder if qemu gets confused by this and thinks that the image is
> > open in two places?
> >
> > I can't reproduce this here however.  Having a nice short reproducer
> > might help.
>
> This bug has now been reported by a Debian user:
>
>   https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=884110
>
> Yaniv, did you file an upstream bug report and/or get a reliable
> reproducer?  I cannot reproduce this at all.
>

I have not, since I cannot reliably reproduce it (it happens ~ 1 of 5 runs
or so).
I wonder if there's additional debug information I can provide, though.

>
> Rich.
>
> --
> Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~
> rjones
> Read my programming and virtualization blog: http://rwmj.wordpress.com
> libguestfs lets you edit virtual machines.  Supports shell scripting,
> bindings from many languages.  http://libguestfs.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/libguestfs/attachments/20171212/3c5a3b8a/attachment.htm>