lxc 3.0.4-0ubuntu1 ADT test failure with linux 5.4.0-1.2

[Seth Forshee]

[ Impact ]

 * Test suite fails due to inexistent device (/dev/network_latency).

[ Test Plan ]

 * Run the test suite.
 * The test should pass.

[ Where problems could occur ]

 * The regression risk is very low, and the changes only affect the tests, so the regression scope is minimal.

[ Other Info ]

Original bug report:

Testing failed on:
    amd64: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-eoan-canonical-kernel-team-unstable/eoan/amd64/l/lxc/20191016_150939_0f81d@/log.gz
    arm64: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-eoan-canonical-kernel-team-unstable/eoan/arm64/l/lxc/20191016_152027_0f81d@/log.gz
    ppc64el: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-eoan-canonical-kernel-team-unstable/eoan/ppc64el/l/lxc/20191016_150251_0f81d@/log.gz
    s390x: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-eoan-canonical-kernel-team-unstable/eoan/s390x/l/lxc/20191016_150201_0f81d@/log.gz

[Christian Brauner (cbrauner)]

Is this a flake or consistently reproducible?

[Stéphane Graber (stgraber)]

Looking at the linked reports, it sounds like either /dev/network_latency doesn't exist in those systems (which would differ from standard kernel behavior on Ubuntu), or there is a legitimate issue with injecting that device afterwards.

In either case, likely to be a kernel config change or a kernel regression.

[Seth Forshee (sforshee)]

On Fri, Oct 18, 2019 at 03:03:43PM -0000, Christian Brauner wrote:
> Is this a flake or consistently reproducible?

It's reproducible.

[Seth Forshee (sforshee)]

Seems /dev/network_latency was removed upstream.

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c3082a674f46fe49383b157882c41dfabaa37113

[Seth Forshee (sforshee)]

Christian: Discussed this bug with stgraber last week. Sounds like /dev/network_latency is just an arbitrary device picked for a test case, and since it's been removed upstream a different device should be used. He said you could get this fixed.

[Christian Brauner (cbrauner)]

Sorry, mail got lost. Here's a fix:
https://github.com/lxc/lxc/pull/3187

[Seth Forshee (sforshee)]

Do you have an ETA on when you'll do an lxc upload with the fix?

[Launchpad Janitor (janitor)]

This bug was fixed in the package lxc - 3.0.4-0ubuntu2

---------------
lxc (3.0.4-0ubuntu2) focal; urgency=medium

  * Cherry-pick upstream bugfixes (LP: #1848587):
    - tests: use /dev/loop-control instead of /dev/network_latency

 -- Stéphane Graber <email address hidden> Tue, 26 Nov 2019 12:22:37 -0500

[Robie Basak (racb)]

Is bionic-proposed sufficient (ie. block-proposed-bionic then) or do you specifically need it in bionic-updates?

[Dimitri John Ledkov (xnox)]

it must be released in bionic-updates.
bionic-proposed is insufficient.
this follows the previous SRUs that fixed adt only, which were awaiting on "an end-user visible sru to come in the future" which never has.
autopkgtest infrastructure has no ability to always test against proposed pocket, a given package, because it's test is regressed in updates.

[Łukasz Zemczak (sil2100)]

Hello Seth, or anyone else affected,

Accepted lxc into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/lxc/3.0.3-0ubuntu1~18.04.3 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Ubuntu SRU Bot (ubuntu-sru-bot)]

All autopkgtests for the newly accepted lxc (3.0.3-0ubuntu1~18.04.3) for bionic have finished running.
The following regressions have been reported in tests triggered by the package:

lxd/3.0.3-0ubuntu1~18.04.2 (i386)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-migration/bionic/update_excuses.html#lxc

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!

[Dimitri John Ledkov (xnox)]

autopkgteest & general usage of lxc 3.0.3-0ubuntu1~18.04.3 works with host kernels on bionic's GA kernel and on hwe v5.4 kernels now.

verification done.

[Dimitri John Ledkov (xnox)]

cross test of lxd fails, but i386 is not supported under ESM and i'm not sure if i386 cross-arch autopkgtest is valid at all.

[Launchpad Janitor (janitor)]

This bug was fixed in the package lxc - 3.0.3-0ubuntu1~18.04.3

---------------
lxc (3.0.3-0ubuntu1~18.04.3) bionic; urgency=medium

  * Fix tests issue by avoiding falling back to inexistent trusty LXC images
    and using the bionic ones (LP: #1939537)

lxc (3.0.3-0ubuntu1~18.04.2) bionic; urgency=medium

  * Cherry-pick upstream bugfixes (LP: #1848587 LP: #1886790):
    - tests: use /dev/loop-control instead of /dev/network_latency
    - This unbreaks adt-matrix / adt testing of Bionic hwe kernels

 -- Andrei Gherzan <email address hidden> Fri, 05 May 2023 14:06:12 +0200

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for lxc has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.