Re: [libvirt] [PATCH v3 5/5] blockcommit: turn on active commit

With this in place, I can (finally!) now do: virsh blockcommit $dom vda --shallow --verbose --pivot and watch qemu shorten the backing chain by one, followed by libvirt automatically updating the dumpxml output, effectively undoing the work of virsh snapshot-commit --no-metadata --disk-only. Commit is SOOOO much faster than blockpull, when I'm still fairly close in time to when the temporary qcow2 wrapper file was created via a snapshot operation! Still not done: the persistent XML is not updated; which means stopping and restarting a persistent guest will use the wrong file and likely fail to boot. * src/qemu/qemu_driver.c (qemuDomainBlockCommit): Implement live commit to regular files. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- src/qemu/qemu_driver.c | 40 +++++++++++++++++++++++++++++++++++----- 1 file changed, 35 insertions(+), 5 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index d19ca18..089668d 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c

@@ -15607,6 +15615,21 @@ qemuDomainBlockCommit(virDomainPtr dom, VIR_DISK_CHAIN_READ_WRITE) < 0)) goto endjob; + /* For an active commit, clone enough of the base to act as the mirror */ + if (mirror) { + /* XXX Support network commits */

+ if (baseSource->type != VIR_STORAGE_TYPE_FILE && + baseSource->type != VIR_STORAGE_TYPE_BLOCK) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("active commit to non-file not supported yet")); + goto endjob; + } + mirror->type = baseSource->type; + if (VIR_STRDUP(mirror->path, baseSource->path) < 0) + goto endjob; + mirror->format = baseSource->format; + } + /* Start the commit operation. Pass the user's original spelling, * if any, through to qemu, since qemu may behave differently * depending on whether the input was specified as relative or