Bug#842299: autopkgtest-virt-qemu: attaching base image makes btrfs very confused

[Christian Seiler]

On 10/30/2016 09:40 PM, Martin Pitt wrote:
> Christian Seiler [2016-10-30 21:12 +0100]:
>> Well, it's not actually SYSTEMD_READY, the "btrfs ready" builtin is
>> actually the culprit.
> 
>> So one needs to make sure the btrfs ready builtin is never executed
>> for the corresponding devices. Which is why I did the LABEL/goto
>> logic in my example.
> 
> So to generalize that a bit: blkid is called in
> 60-persistent-storage.rules, so we could add a rule to the already
> existing /run/udev/rules.d/61-baseimage.rules:
> 
>      KERNEL=="vd*", ENV{ID_SERIAL}=="BASEIMAGE", ENV{ID_FS_TYPE}="", ENV{ID_FS_USAGE}="", ENV{ID_FS_UUID}=""
> 
> This should short-circuit 64-btrfs.rules and any similar rules. This
> at least works in a VM with ext4.

Yes, that looks very reasonable and future-proof. Let's test if
that actually works with btrfs.

Regards,
Christian