Re: s390 intermittent test failure in qemu:block / io-qcow2-copy-before-write

[Christian Borntraeger <borntraeger@linux.ibm.com>]

Am 25.07.23 um 18:45 schrieb Peter Maydell:
> There seems to be an intermittent failure on the s390 host in
> the qemu:block / io-qcow2-copy-before-write test:
> https://gitlab.com/qemu-project/qemu/-/jobs/4737819873
> 
> The log says the test was expecting to do some reading
> and writing but got an unexpected 'permission denied'
> error on the read. Any idea why this might happen ?
> 
> 768/835 qemu:block / io-qcow2-copy-before-write ERROR 12.05s exit status 1
>>>> PYTHON=/home/gitlab-runner/builds/-LCfcJ2T/0/qemu-project/qemu/build/pyvenv/bin/python3 MALLOC_PERTURB_=101 /home/gitlab-runner/builds/-LCfcJ2T/0/qemu-project/qemu/build/pyvenv/bin/python3 /home/gitlab-runner/builds/-LCfcJ2T/0/qemu-project/qemu/build/../tests/qemu-iotests/check -tap -qcow2 copy-before-write --source-dir /home/gitlab-runner/builds/-LCfcJ2T/0/qemu-project/qemu/tests/qemu-iotests --build-dir /home/gitlab-runner/builds/-LCfcJ2T/0/qemu-project/qemu/build/tests/qemu-iotests
> ――――――――――――――――――――――――――――――――――――― ✀ ―――――――――――――――――――――――――――――――――――――
> stderr:
> --- /home/gitlab-runner/builds/-LCfcJ2T/0/qemu-project/qemu/tests/qemu-iotests/tests/copy-before-write.out
> +++ /home/gitlab-runner/builds/-LCfcJ2T/0/qemu-project/qemu/build/scratch/qcow2-file-copy-before-write/copy-before-write.out.bad
> @@ -1,5 +1,21 @@
> -....
> +...F
> +======================================================================
> +FAIL: test_timeout_break_snapshot (__main__.TestCbwError)
> +----------------------------------------------------------------------
> +Traceback (most recent call last):
> + File "/home/gitlab-runner/builds/-LCfcJ2T/0/qemu-project/qemu/tests/qemu-iotests/tests/copy-before-write",
> line 210, in test_timeout_break_snapshot
> + self.assertEqual(log, """\
> +AssertionError: 'wrot[195 chars]read 1048576/1048576 bytes at offset
> 0\n1 MiB,[46 chars]c)\n' != 'wrot[195 chars]read failed: Permission
> denied\n'
> + wrote 524288/524288 bytes at offset 0
> + 512 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> + wrote 524288/524288 bytes at offset 524288
> + 512 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> ++ read failed: Permission denied
> +- read 1048576/1048576 bytes at offset 0
> +- 1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +
> +
> ----------------------------------------------------------------------
> Ran 4 tests
> -OK
> +FAILED (failures=1)
> (test program exited with status code 1)
> ――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
> 
> Same failure, previous job:
> 
> https://gitlab.com/qemu-project/qemu/-/jobs/4736463062
> 
> This one's a "Failed to get write lock" in io-qcow2-161:
> 
> https://gitlab.com/qemu-project/qemu/-/jobs/4734846533

See
https://lore.kernel.org/qemu-devel/028059df-eaf4-9e65-a195-4733b708a426@linux.ibm.com/

I was not yet able to understand that. And I can only reproduce with Ubuntu (RHEL,SLES,Fedora are fine).
Upstream kernel on Ubuntu does not help, so I assume it must be something in the libraries or config.