Re: [libvirt] [PATCH] qemu: blockCopy: Allow shallow block copy into a raw image

On Mon, Apr 27, 2015 at 22:11:40 +0800, Shanzhi Yu wrote: > > On 04/27/2015 08:01 PM, Peter Krempa wrote: >> The documentation states that for shallow block copy the image has to >> have the same guest visible content as backing file of the current >> image. This condition can be achieved also with a raw file (or a qcow >> without a backing file) so remove the condition that would disallow it. >> >> (This patch additionally fixes crash described in >> https://bugzilla.redhat.com/show_bug.cgi?id=1215569 since it removes >> the code) >> --- >> src/qemu/qemu_driver.c | 10 ---------- >> 1 file changed, 10 deletions(-) >> >> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c >> index 70bf7aa..f979d33 100644 >> --- a/src/qemu/qemu_driver.c >> +++ b/src/qemu/qemu_driver.c >> @@ -16815,16 +16815,6 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm, >> if (qemuDomainDetermineDiskChain(driver, vm, disk, false, true) < 0) >> goto endjob; >> >> - if ((flags & VIR_DOMAIN_BLOCK_COPY_SHALLOW) && >> - mirror->format == VIR_STORAGE_FILE_RAW && >> - disk->src->backingStore->path) { >> - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, >> - _("disk '%s' has backing file, so raw shallow copy " >> - "is not possible"), >> - disk->dst); >> - goto endjob; >> - } >> - > Although a shallow blockcopy of file without backing file is > semantically correct, but still feel a little weird. > And, a shallow blockcommit of file without backing file will failed with > error > "error: invalid argument: top '/var/lib/libvirt/images/raw.img' in chain > for 'vda' has no backing file" > > Should libvirt post error when try a shallow blockcopy of file without > backing file, just as shallow blockcommit? I cannot reproduce the error above, could you please post steps to do that? or perhaps debug log from libvirt?

When copying from a single layer image with the --shallow flag I'm able to successfully copy both into a raw and a qcow2 file.

>> /* Prepare the destination file. */ >> /* XXX Allow non-file mirror destinations */ >> if (!virStorageSourceIsLocalStorage(mirror)) { Peter