Re: [libvirt] [PATCH 11/17] util: Introduce libvirt_udevhelper
On Thu, Oct 27, 2016 at 03:37:59PM +0200, Michal Sekletar wrote:
On Thu, Oct 27, 2016 at 2:48 PM, Daniel P. Berrange
<berrange(a)redhat.com> wrote:
> We absolutely don't want to be delegating permissions setting/labelling
> to udev & waiting for it to complete asychronously in the background.
> That leads to two completely different approaches for labelling files
> vs block devices making debugging harder and the overall system more
> complex & error prone.
libvirtd would chown and relabel but it would also trigger change
event after it populates devices.udev. To make sure any change event
that was possibly running before won't change permissions back.
Waiting will be synchronous on libvirtd side. I admit it is a bit ugly
but I think there is no other way how to solve this problem.
We can not do any sychronous wait against udev doing work - that will
add an unacceptable delay in the VM startup process - it is already
too long and we don't want to design a system that will make it even
slower.
Regards,
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :|