A bug will be hitted with libvirt+qemu+kvm when doing follow steps: 1.initial status :vm = base+z(z is a snapshot) 2. call snapshotCreateXML( ): vm = base+z +z' 3. call blockRebase( ): vm = base+z''(z rebase to z') 4.(after rebasing work done) vm shutdown and then start an error occured like this: "unable to set user and group to '0:0' on ' /path/to/disk': No such file or directory A second start may sucess. The error message reported by virSecurityDACSetSecurityDiskLabel when the disk chain is misused(that is base+z +z', after rebase, but z' was deleted yet).virSecurityDACSetSecurityDiskLabel used an old disk chain after rebasing. In qemuProcessHandleBlockJob when rebase complete, the disk chain in vm->def is updated but vm->newDef is not(when vm->newDef is not null). In shutdown( actrully in qemuProcessStop ), if vm->newDef is not null , vm->def will be replaced by vm->newDef, which contains a wrong disk chain!!! Then the next start will failed with above message. To fix it, update disk chain in vm->newDef in qemuProcessHandleBlockJob. Signed-off-by: Weiwei Li <nuonuoli(a)tencent.com&gt; --- src/qemu/qemu_process.c | 27 +++++++++++++++++++++++++++ 1 files changed, 27 insertions(+), 0 deletions(-) diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 24e5f0f..0491249 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -1033,6 +1033,7 @@ qemuProcessHandleBlockJob(qemuMonitorPtr mon ATTRIBUTE_UNUSED, virDomainDiskDefPtr disk; virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver); virDomainDiskDefPtr persistDisk = NULL; + virDomainDiskDefPtr newDisk = NULL; bool save = false; virObjectLock(vm); @@ -1101,6 +1102,32 @@ qemuProcessHandleBlockJob(qemuMonitorPtr mon ATTRIBUTE_UNUSED, disk->mirrorJob = VIR_DOMAIN_BLOCK_JOB_TYPE_UNKNOWN; ignore_value(qemuDomainDetermineDiskChain(driver, vm, disk, true, true)); + /* Chang vm->newDef disk chain */ + if (!persistDisk && vm->newDef){ + int indx = virDomainDiskIndexByName(vm->newDef, + disk->dst, + false); + virStorageSourcePtr copy = NULL; + + if (indx >=0){ + newDisk = vm->newDef->disks[indx]; + copy = virStorageSourceCopy(disk->src, false); + if (virStorageSourceInitChainElement(copy, + newDisk->src, + false) < 0) { + VIR_WARN("Unable to update newDef definition " + "on vm %s after block job", + vm->def->name); + virStorageSourceFree(copy); + copy = NULL; + newDisk = NULL; + } + } + if (copy){ + virStorageSourceFree(newDisk->src); + newDisk->src = copy; + } + } } else if (disk->mirror && (type == VIR_DOMAIN_BLOCK_JOB_TYPE_COPY || type == VIR_DOMAIN_BLOCK_JOB_TYPE_ACTIVE_COMMIT)) { -- 1.7.1