lxc 3.0.3-0ubuntu1~18.04.1 ADT test failure with B/5.4 kernels (device_add_remove_test)

[Kleber Sacilotto de Souza]

[ Impact ]

 * The device_add_remove_test test fails on the affected series (e.g. Bionic).
 * Having the test fixed for the affected series (for example, Bionic) will allow us to run the LXC test suite without maintaining local changes for this test.

[ Test Plan ]

 * Run the affected test on an affected series (e.g. Bionic).
 * 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 ]

Upstream drop of network_latency: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c3082a674f46fe49383b157882c41dfabaa37113
Related to: https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1848587

Original bug report:

Testing failed on:
    amd64: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-bionic/bionic/amd64/l/lxc/20200706_183234_ca65f@/log.gz
    arm64: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-bionic/bionic/arm64/l/lxc/20200706_172136_71b68@/log.gz
    ppc64el: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-bionic/bionic/ppc64el/l/lxc/20200706_191938_cedac@/log.gz
    s390x: https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-bionic/bionic/s390x/l/lxc/20200706_163359_98d4d@/log.gz

The failing test seems to be:

FAIL: lxc-tests: lxc-test-device-add-remove (0s)
---
Adding /dev/network_latency to the container (device_add_remove_test) failed...
---

This is a regression from the 4.15/5.3 to 5.4 kernels in Bionic. Note that this testcase is successful on Focal with the same kernel version.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Christian Brauner (cbrauner)]

This is a bug we fixed in our stable-3.0 branch and is fixed in the Ubuntu lxc 3.0.4 packages. See
https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1848587
and specifically this commit:

commit 11fc6882f7bfd40fbcda6a3a7f7c1bca50df3f2b
Author: Christian Brauner <email address hidden>
Date: Mon Nov 18 15:08:22 2019 +0100

    tests: use /dev/loop-control instead of /dev/network_latency

    BugLink: https://bugs.launchpad.net/bugs/1848587

    The latter device has been removed apparently.

Bionic didn't get the 3.0.4 upgrade? That seems odd.

[Kleber Sacilotto de Souza (kleber-souza)]

This is a testcase issue, so I'm lowering the importance to 'Medium'.

[Guilherme G. Piccoli (gpiccoli)]

Observed on B/aws-5.4 , cycle 20210621.

[Guilherme G. Piccoli (gpiccoli)]

Observed this on B/oracle-5.4, cycle sru-20210621 .

[Krzysztof Kozlowski (krzk)]

Found on bionic/azure-5.4 5.4.0-1056.58~18.04.1 (and previous cycle 5.4.0-1054.56~18.04.1)

[Tim Gardner (timg-tpi)]

Observed on bionic:linux-aws-5.4 5.4.0-1055.58~18.04.1

[Marcelo Cerri (mhcerri)]

Observed on bionic:linux-azure-5.4 5.4.0-1056.58~18.04.1 .

[Po-Hsu Lin (cypressyew)]

Spotted on linux-gkeop-5.4/5.4.0-1024.25~18.04.1

[Dimitri John Ledkov (xnox)]

we ought to sponosr http://launchpadlibrarian.net/453184210/lxc_3.0.4-0ubuntu1_3.0.4-0ubuntu2.diff.gz into bionic

[Dimitri John Ledkov (xnox)]

sponsored into unapproved queue

[Łukasz Zemczak (sil2100)]

Hello Kleber, 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.

[Po-Hsu Lin (cypressyew)]

Hints removed, closing this bug.