[Build 2023050602-4.2] sys-net and sys-usb sometimes very slowly shut down

[marmarek]

Observation

openQA test in scenario qubesos-4.2-pull-requests-x86_64-system_tests_basic_vm_qrexec_gui_btrfs@64bit fails in
switch_pool

https://openqa.qubes-os.org/tests/73030/logfile?filename=serial_terminal.txt shows qubes-firewall is stopping very slowly in both sys-net and sys-usb, but in sys-net case, there is also some timeout related to user session.

Test suite description

basic tests on BTRFS filesystem (reflink pool)
The test fails during migrating all the VMs into the new pool

Reproducible

Fails since (at least) Build 2023050602-4.2

Note this is a test run with those PRs included on top of normal packages:

• Jail qfile-unpacker in an SELinux sandbox qubes-core-agent-linux#422
• ext/admin: update parameters for policy-related methods qubes-core-admin#534
• Work around race condition in network tests qubes-core-admin#533
• Xen hotplug scripts should be initrc_exec_t qubes-core-agent-linux#419
• qubes-block: force logical block size 512 for loop device qubes-linux-utils#94
• Improve tests qubes-core-admin#528
• Switch to nftables qubes-core-agent-linux#407
• Do not allow + to separate subpacket numbers qubes-app-linux-split-gpg#90
• Pass all focus events to clients qubes-gui-daemon#104
• btrfs rootfs support qubes-linux-utils#82

Expected result

Last good: 2023050503-4.2 (or more recent)

Further details

Always latest result in this scenario: latest