Bug 1162974

Created attachment 956560 [details]
libvirtd back trace file

Description of problem:
when do external disk snapshot with fault gluster network snapshot xml, libvirtd crashed.
The fault xml is generated accidentally, with the right one it could succeed. 

Version-Release number of selected component (if applicable):
libvirt-1.2.8-6.el7.x86_64
glusterfs-3.5.2-1.el7.x86_64
qemu-kvm-rhev-2.1.2-6.el7.x86_64
kernel-3.10.0-123.el7.x86_64

How reproducible:
always

Steps to Reproduce:
1. prepare a domain with gluster network disk
# virsh dumpxml virt-tests-vm1
...
    <disk type='network' device='disk'>
      <driver name='qemu' type='qcow2' cache='none'/>
      <source protocol='gluster' name='gluster-vol1/rhel7.img'>
        <host name='xx.xx.xx.xx'/>
      </source>
      <backingStore/>
      <target dev='vda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </disk>
...

# virsh list
 Id    Name                           State
----------------------------------------------------
 4     virt-tests-vm1                 running

2. prepare a fault snapshot xml
# cat /tmp/gluster_snap.xml 
<domainsnapshot>
<name>snapshot_test</name>
<description>Snapshot Test</description>
<disks>
<disk name='vda' snapshot='external' type='network'>
<source protocol='gluster' name='gluster-vol1/gluster.qcow2.snap'/>
</disk>
</disks>
</domainsnapshot>

Note:
The <source> element closed without <host/> given

3. do external disk snapshot with the xml
# virsh snapshot-create virt-tests-vm1 /tmp/gluster_snap.xml --disk-only
2014-11-12 05:25:19.353+0000: 14192: info : libvirt version: 1.2.8, package: 6.el7 (Red Hat, Inc. <http://bugzilla.redhat.com/bugzilla>, 2014-11-04-08:28:35, x86-020.build.eng.bos.redhat.com)
2014-11-12 05:25:19.353+0000: 14192: warning : virKeepAliveTimerInternal:143 : No response from client 0x7f9784181dd0 after 6 keepalive messages in 35 seconds
error: internal error: received hangup / error event on socket
2014-11-12 05:25:19.354+0000: 14194: warning : virKeepAliveTimerInternal:143 : No response from client 0x7f9784181dd0 after 6 keepalive messages in 35 seconds
error: Failed to reconnect to the hypervisor


Actual results:
libvirtd crashed

Expected results:
no crash

Additional info:
backtrace in attachment