Status changed to 'Confirmed' because the bug affects multiple users.
** Changed in: linux (Ubuntu Jammy)
Status: New => Confirmed
--
You received this bug notification because you are a member of
Canonical's Ubuntu QA, which is subscribed to autopkgtest in Ubuntu.
Matching subscriptions: ubuntu-qa-bugs
https://bugs.launchpad.net/bugs/2056461
Title:
autopkgtest-virt-qemu on noble images sometimes hangs doing copydown
Status in Linux:
Confirmed
Status in autopkgtest package in Ubuntu:
Fix Released
Status in linux package in Ubuntu:
In Progress
Status in autopkgtest source package in Jammy:
In Progress
Status in linux source package in Jammy:
Confirmed
Status in autopkgtest source package in Noble:
In Progress
Status in linux source package in Noble:
Confirmed
Status in autopkgtest package in Debian:
Fix Released
Bug description:
[Impact]
It seems that kernel 6.8 introduced a regression in the 9pfs related
to caching and netfslib, that can cause some user-space apps to read
content from files that is not up-to-date (when they are used in a
producer/consumer fashion).
It seems that the offending commit is this one:
80105ed2fd27 ("9p: Use netfslib read/write_iter")
Reverting the commit seems to fix the problem. However the actual bug
might be in netfslib or how netfslib is used in the 9p context.
The regression has been reported upstream and we are still
investigating (https://lore.kernel.org/lkml/Zj0ErxVBE3DYT2Ea@gpd/).
In the meantime it probably makes sense to temporarily revert the
commit as a SAUCE patch. Then we will drop the SAUCE patch once we'll
have a proper fix upstream.
[Test case]
The following test should complete correctly without any timeout:
pull-lp-source -d hello
autopkgtest-buildvm-ubuntu-cloud -r noble
autopkgtest -U hello*.dsc -- qemu ./autopkgtest-noble-amd64.img
[Fix]
Revert the following commit (until we have a proper fix upstream):
80105ed2fd27 ("9p: Use netfslib read/write_iter")
[Regression potential]
We may experience other regressions related to 9pfs with this change,
however it's quite unlikely to happen since we are reverting a commit,
restoring the previous behavior.
[Original bug report]
autopkgtest-virt-qemu sometimes hangs when running tests on noble
images. Originally reported by schopin, who also provided a
reproducer:
pull-lp-source -d hello
autopkgtest-buildvm-ubuntu-cloud -r noble
autopkgtest -U hello*.dsc -- qemu ./autopkgtest-noble-amd64.img
I've been able to reproduce it with debugging enabled:
autopkgtest -ddd -U hello_2.10-3.dsc -- qemu --debug --show-boot
/path/to/image
It can get stuck during different stages, but AFAICT always during
"copydown" operations, log excerpts follow. It may be a coincidence,
but this started happening around the time linux-
image-6.8.0-11-generic (6.8.0-11.11) migrated to noble. The testbeds I
used booted 6.6 but then rebooted into that 6.8 kernel after being
upgraded by autopkgtest.
-- logs --
Removing autopkgtest-satdep (0) ...
[...]
autopkgtest-virt-qemu: DBG: executing copydown
/tmp/autopkgtest.output.g8v75e8g/tests-tree/ /t/
autopkgtest-virt-qemu: DBG: ['cmdls', "(['tar', '--directory',
'/tmp/autopkgtest.output.g8v75e]
autopkgtest-virt-qemu: DBG: ['srcstdin', "<_io.BufferedReader
name='/dev/null'>", 'deststdout']
autopkgtest-virt-qemu: DBG: +< tar --directory
/tmp/autopkgtest.output.g8v75e8g/tests-tree/ --
autopkgtest-virt-qemu: DBG: +> /tmp/autopkgtest-qemu.ztmr6f5k/runcmd sh -ec
if ! test -d /tmp-
autopkgtest-virt-qemu: DBG: +>?
-- or --
autopkgtest: DBG: sending command to testbed: copydown
/tmp/autopkgtest.output.c9utq3bx/tests-tree/
/tmp/autopkgtest.H8NDfW/build.DLR/src/
autopkgtest-virt-qemu: DBG: executing copydown
/tmp/autopkgtest.output.c9utq3bx/tests-tree/
/tmp/autopkgtest.H8NDfW/build.DLR/src/
autopkgtest-virt-qemu: DBG: ['cmdls', "(['tar', '--directory',
'/tmp/autopkgtest.output.c9utq3bx/tests-tree/', '--warning=none', '-c', '.',
'-f', '-'], ['/tmp/autopkgtest-qemu.qtkcgg5l/runcm]
autopkgtest-virt-qemu: DBG: ['srcstdin', "<_io.BufferedReader
name='/dev/null'>", 'deststdout', "<_io.BufferedReader name='/dev/null'>",
'devnull_read', <_io.BufferedReader name='/dev/null'>]
autopkgtest-virt-qemu: DBG: +< tar --directory
/tmp/autopkgtest.output.c9utq3bx/tests-tree/ --warning=none -c . -f -
autopkgtest-virt-qemu: DBG: +> /tmp/autopkgtest-qemu.qtkcgg5l/runcmd sh -ec
if ! test -d /tmp/autopkgtest.H8NDfW/build.DLR/src/; then mkdir --
/tmp/autopkgtest.H8NDfW/build.DLR/src/; fi; cd-
autopkgtest-virt-qemu: DBG: +>?
To manage notifications about this bug go to:
https://bugs.launchpad.net/linux/+bug/2056461/+subscriptions
--
Mailing list: https://launchpad.net/~canonical-ubuntu-qa
Post to : canonical-ubuntu-qa@lists.launchpad.net
Unsubscribe : https://launchpad.net/~canonical-ubuntu-qa
More help : https://help.launchpad.net/ListHelp
