[libvirt] [PATCH] qemu: turn on virtlockd by default

[Daniel P. Berrange]

On Wed, Feb 01, 2017 at 07:04:54PM +0100, Peter Krempa wrote:
> On Wed, Feb 01, 2017 at 16:54:01 +0000, Daniel Berrange wrote:
> > The virtlockd daemon has existed for years now, but we have never
> > turned it on by default, requiring explicit user opt-in. This leaves
> > users unprotected against accidents out of the box.
> > 
> > By turning it on by default, users will at least be protected for
> > mistakes involving local files, and files on shared filesystems
> > that support fcntl() (eg NFS).
> > 
> > In turning it on the various services files are updated to have
> > the same dependancies for virtlockd as we have for virtlogd
> > now, since turning the latter on exposed some gaps.
> > 
> > Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
> > ---
> 
> Unfortunately ... NACK, while I fixed quite some bugs with locking and
> block jobs few of them are still present. Mostly non-active layer block
> commit where we will leak the locked file once we finish the job as we
> are not tracking the job progress ( and nor can we properly do so since
> qemu jobs vanish right after finishing). I discussed it today with Kevin
> Wolf and John Snow and they plan to add a way for the jobs to linger.

Can't we detrect completion / error via the the block job events, even
if the actual job object itself vanishes ? The events look like that
contain enough info to correlate back to libvirt's record of the job.
This would avoid reliance on a new QEMU release

Regards,
Daniel
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