Bug 1002938

Description of problem:
There are two hosts, host0 and host1. The host0 has the disk file also share this file using nfs. The host1 has mounted the nfs share on the same path as the file is in host0 "mount -t nfs host0:/some/path/to/images /some/path/to/images".

Migration from host0 to host1 using command "virsh migrate --live --undefinesource --persistent --domain guest --desturi qemu+ssh://host0/system --timeout 60" works fine, but the migration back from host1 to host0 using command "virsh migrate --live --undefinesource --persistent --domain guest --desturi qemu+ssh://host0/system --timeout 60" fails.

The issue is with xml config of the guest. On host1 has the guest in migratable dumpxml "<seclabel model='selinux' relabel='no'/>" this option for disk, but in inactive dumpxml there isn't that option. The host1 adds this option because the disk is from nfs share and libvirt cannot change the selinux label.

Version-Release number of selected component (if applicable):
libvirt-0.10.2-23.el6.x86_64

How reproducible:
100%

Steps to Reproduce:
1. prepare and run the guest on host0
2. on host0 run "service nfs start" and "exportfs -o rw *:/some/path/to/images"
3. on host1 mount the nfs "mkdir -p /some/path/to/images" and "mount -t nfs host0://some/path/to/images /some/path/to/images"
4. on host1 also enable nfs share for libvirt "setsebool -P virt_use_nfs on"
5. run the migration from host0 to host1 "virsh migrate --live --undefinesource --persistent --domain guest --desturi qemu+ssh://host0/system --timeout 60"
6. run the migration from host1 to host0 "virsh migrate --live --undefinesource --persistent --domain guest --desturi qemu+ssh://host0/system --timeout 60"

Actual results:
After step 6:
error: internal error process exited while connecting to monitor: char device redirected to /dev/pts/1
qemu-kvm: -drive file=/some/path/to/images/guest.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none: could not open disk image /some/path/to/images/guest.qcow2: Permission denied

Expected results:
The migration should complete.