On 07/15/2015 10:33 AM, Peter Krempa wrote:
Few parts of the code looked at the current progress of and assumed that a two phase blockjob is in the _READY state as soon as the progress reached 100% (info.cur == info.end). In current versions of qemu this assumption is invalid and qemu exposes a new flag 'ready' in the query-block-jobs output that is set to true if the job is actually finished.
This patch adds internal data handling for reading the 'ready' flag and acting appropriately as long as the flag is present.
While this still doesn't fix the virsh client problem with two phase block jobs and the --pivot option, it at least improves the error message:
$ virsh blockcommit --wait --verbose vm vda --base vda[1] --active --pivot Block commit: [100 %]error: failed to pivot job for disk vda error: internal error: unable to execute QEMU command 'block-job-complete': The active block job for device 'drive-virtio-disk0' cannot be completed
to
$ virsh blockcommit --wait --verbose VM vda --base vda[1] --active --pivot Block commit: [100 %]error: failed to pivot job for disk vda error: block copy still active: disk 'vda' not ready for pivot yet
Thanks for working on this. I think part of the problem is that newer qemu races, and can report info.cur == info.end == 0 very early in the process before starting to report non-zero info.end, but info.ready is correctly false in that point. You're right that this doesn't solve virsh racing when it sees info.cur == info.end as a potential job complete condition (where special-casing 0 then runs into problems for no-op jobs where there really is no work to do and the job can end instantly), but using the extra information from qemu does look like an improvement. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org