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

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(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. This bug has now been reported by a Debian user: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=884110