Updates keep coming in while writable image is set

[Sergio Schvezov]

I've been updating whilst having writable image set.

root@ubuntu-phablet:~# system-image-cli -i
current build number: 104
device name: mako
channel: ubuntu-touch/devel-proposed
alias: ubuntu-touch/utopic-proposed
last update: 2014-06-29 04:47:42
version version: 104
version ubuntu: 20140629
version device: 20140625
root@ubuntu-phablet:~# ls -lh /userdata/.writable_image
-rw-rw-rw- 1 root root 0 Jun 22 14:37 /userdata/.writable_image

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: system-image-common 2.2-0ubuntu1
Uname: Linux 3.4.0-5-mako armv7l
ApportVersion: 2.14.3-0ubuntu2
Architecture: armhf
Date: Sun Jun 29 05:00:12 2014
InstallationDate: Installed on 2014-06-29 (0 days ago)
InstallationMedia: Ubuntu Utopic Unicorn (development branch) - armhf (20140629-020204)
PackageArchitecture: all
SourcePackage: system-image
UpgradeStatus: No upgrade log present (probably fresh install)

[Barry Warsaw (barry)]

This is basically a feature, not a bug. system-image-cli is a developer tool, as is writable mode. Developers are supposed to know what they're doing, so s-i-cli never changes its behavior based on writable mode and in fact never looks at /userdata/.writable_image.
You would have to pass `--build 0` to force a full update.

In IRC discussions, Sergio mentioned that it worked differently in Saucy, where if writable mode was set, no updates would happen via the system-settings ui. If that behavior's changed, then it's a ui bug. Note that system-image-dbus also does not look at /userdata/.writable_image and does not change behavior based on writable mode, however s-i-dbus is purely triggered through D-Bus activation, which typically is only invoked by the systems-setting ui.

[Sergio Schvezov (sergiusens)]

Hey Barry, there's a design entry for providing factory reset[1]. One of
the ideas that circles around is to add a new method, let's call it Format,
to an existing or new interface in system image to basically do:

echo "format data" > /cache/recovery/ubuntu_command

I guess it's the right fit since this way we can easily lock an upgrade
from a factory reset taking place at the same time.

What do you think? I can take stance later if it seems appropriate or
people time becomes a blocking factor.

Cheers
Sergio.

[1] https://wiki.ubuntu.com/SystemSettings#A.2BIBw-Reset_Phone.2BIB0-

[Barry Warsaw (barry)]

The time machine strikes again! LP: #1207860

The method is called FactoryReset() and it will be included in system-image 2.3 (hopefully coming early next week).

FactoryReset() is documented here:

https://wiki.ubuntu.com/ImageBasedUpgrades/Client