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

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(a)redhat.com&gt; > 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/06df910491c49360c0292c7153b... 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.