[Pkg-libvirt-maintainers] Bug#998090: libvirt-daemon-system: Please defer starting libvirtd.socket until libvirtd.service dependencies can be met

[Michael Biebl]

On Sat, 30 Oct 2021 17:39:45 +1030 Ron <ron at debian.org> wrote:
> Package: libvirt-daemon-system
> Version: 7.0.0-3
> Severity: important
> 
> Hi,
> 
> Systemd has a class of boot-time races which can result in deadlock,
> which I learned more than I ever wanted to know about when Buster to
> Bullseye upgrades started leaving me with machines that were off the
> network when they were rebooted ...  The reason for that is a bit of a
> tangle of otherwise unrelated packages, and there are many ways this
> *could* happen, but the root of it in my particular case was the libvirt
> package switching to use socket activation instead of letting the daemon
> create its own socket when it is ready to respond to requests on it.
> 
> The race occurs because the .socket unit creates the libvirt control
> socket very early in the boot, before even the network-pre target is
> reached, and so long before the libvirtd.service dependencies are
> satisfied and the daemon itself can be started to handle requests.

There is nothing to fix on the libvirt / ifupdown side here.

The bug is in bit-babbler which triggers the start of a long running process
from a udev rules file (which it shouldn't do), which causes the dead lock
in the end.

I tried to explain this to Ron on IRC, but he decided to ignore my advice.

Please ignore this bug report.
If you have further questions, feel free to contact me.

Regards,
Michael
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: This is a digitally signed message part
URL: <http://alioth-lists.debian.net/pipermail/pkg-libvirt-maintainers/attachments/20211102/36bbc160/attachment.sig>