Disable service activation from dbus-broker while dbus-broker.service is deactivating #26799

Geass-LL · 2023-03-14T02:46:05Z

Component

systemd

Is your feature request related to a problem? Please describe

I'm using systemctl isolate reboot.target to reboot the system. But since I changed the default D-Bus daemon from dbus-daemon to dbus-broker, the reboot process is always terminated. This is because NetworkManager.service will activate NetworkManager-dispatcher.service when it is stopped, and this start job makes many stop jobs canceled.

I'm curious why this NetworkManager-dispatcher.service start job was not generated when I use dbus-daemon, and find systemd will refuse this job when dbus-daemon is shutting down in signal_activation_request(). But this doesn't work on dbus-broker, because dbus-broker uses StartUnit methon_call directly instead of ActivationRequest signal. See https://github.com/bus1/dbus-broker/blame/main/NEWS.md#L693. systemd seems doesn't have similar code for dbus-broker.

Describe the solution you'd like

I want systemd to refuse the service activation while dbus-broker.service is deactivating.

Describe alternatives you've considered

I have considered 2 alternatives:

Broadcasting signal DBusDeactivating so dbus-broker knows it will be stopped, and dbus-broker can refuse the StartUnit message.
Check the state of dbus-broker and the the type of service waitting to be activated, if dbus-broker is deactivating, systemd refuses to activate Type=dbus services.

The systemd version you checked that didn't have the feature you are asking for

No response

The text was updated successfully, but these errors were encountered:

poettering · 2023-03-15T10:35:28Z

This is because NetworkManager.service will activate NetworkManager-dispatcher.service when it is stopped, and this start job makes many stop jobs canceled.

Hmm? it does what? it starts new services during shutdown? it really shouldn't do that. This is what should be fixed.

poettering · 2023-03-15T10:36:50Z

2. Check the state of dbus-broker and the the type of service waitting to be activated, if dbus-broker is deactivating, systemd refuses to activate Type=dbus services.

this sounds better to me actually. but yuck, nm shouldn't do what it is doing. starting up a lot of infra when shutting down, reversing the shutdown transaction is just a bad idea.

Replaces systemd#27570 Closes systemd#26799

dbus-broker issues StartUnit directly for activation requests, so let's add a check on bus state in bus_unit_queue_job to refuse that if dbus is not running. Replaces systemd#27570 Closes systemd#26799

Follow-up for systemd#27579 In systemd#27579 we refused all StartUnit requests for Type=dbus units if dbus is not running, which means if dbus is manually stopped, user can't use systemctl to start Type=dbus units again, which is incorrect. The culprit that leads to the cancellation of the whole transaction mentioned in systemd#26799 is job type conflict on dbus. On the other hand, if the stop job is already running, or dbus is already inactive, everything should be fine. So let's relax the restriction and only refuse job enqueue if dbus has a pending stop job. To summerize, the case we want to avoid is: 1. dbus has a pending stop job 2. StartUnit/ActivationRequest is received 3. Type=dbus service gets started, which has Requires=dbus.socket 4. dbus is pulled in again, resulting in job type conflict What we can support is: 1. dbus is already stopping (in UNIT_DEACTIVATING) 2. StartUnit is received (possibly through systemctl, i.e. private bus) 3. Type=dbus service gets started, and will wait for running jobs for dbus to complete 4. dbus is started again, and Type=dbus service follows Fixes systemd#27588

Follow-up for systemd#27579 In systemd#27579 we refused all StartUnit requests for Type=dbus units if dbus is not running, which means if dbus is manually stopped, user can't use systemctl to start Type=dbus units again, which is incorrect. The only culprit that leads to the cancellation of the whole transaction mentioned in systemd#26799 is job type conflict on dbus. In other words, if the stop job is already running, or dbus is already inactive, everything should be fine. So let's relax the restriction and only refuse job enqueuing if dbus has a *pending* stop job. To summarize, the case we want to avoid is: 1. dbus has a pending stop job 2. StartUnit/ActivationRequest is received 3. Type=dbus service gets started, which has Requires=dbus.socket 4. dbus is pulled in again, resulting in job type conflict What we can support is: 1. dbus is already stopping (in UNIT_DEACTIVATING) 2. StartUnit is received (possibly through systemctl, i.e. on private bus) 3. Type=dbus service gets started, and will wait for running jobs for dbus to complete 4. dbus is started again, thus the Type=dbus service Fixes systemd#27588

Follow-up for systemd#27579 In systemd#27579 we refused all StartUnit requests for Type=dbus units if dbus is not running, which means if dbus is manually stopped, user can't use systemctl to start Type=dbus units again, which is incorrect. The only culprit that leads to the cancellation of the whole transaction mentioned in systemd#26799 is job type conflict on dbus. So let's relax the restriction and only refuse job enqueuing if dbus has a stop job. To summarize, the case we want to avoid is: 1. dbus has a stop job installed 2. StartUnit/ActivationRequest is received 3. Type=dbus service gets started, which has Requires=dbus.socket 4. dbus is pulled in again, resulting in job type conflict What we can support is: 1. dbus is already stopped 2. StartUnit is received (possibly through systemctl, i.e. on private bus) 3. Type=dbus service gets started 4. dbus is started again, thus the Type=dbus service Replaces systemd#27590 Fixes systemd#27588

Follow-up for systemd#27579 In systemd#27579 we refused all StartUnit requests for Type=dbus units if dbus is not running, which means if dbus is manually stopped, user can't use systemctl to start Type=dbus units again, which is incorrect. The only culprit that leads to the cancellation of the whole transaction mentioned in systemd#26799 is job type conflict on dbus. So let's relax the restriction and only refuse job enqueuing if dbus has a stop job. To summarize, the case we want to avoid is: 1. dbus has a stop job installed 2. StartUnit/ActivationRequest is received 3. Type=dbus service gets started, which has Requires=dbus.socket 4. dbus is pulled in again, resulting in job type conflict What we can support is: 1. dbus is already stopped 2. StartUnit is received (possibly through systemctl, i.e. on private bus) 3. Type=dbus service gets started, which will wait for dbus to start 4. dbus is started again, thus the job for Type=dbus service Replaces systemd#27590 Fixes systemd#27588

Geass-LL added the RFE 🎁 Request for Enhancement, i.e. a feature request label Mar 14, 2023

github-actions bot added the pid1 label Mar 14, 2023

Geass-LL mentioned this issue May 8, 2023

core/dbus-unit: disable service activation while dbus-broker.service … #27570

Closed

YHNdnzj added a commit to YHNdnzj/systemd that referenced this issue May 8, 2023

core: refuse dbus activation if dbus is not running

135b682

Replaces systemd#27570 Closes systemd#26799

YHNdnzj mentioned this issue May 8, 2023

core: refuse dbus activation if dbus is not running #27579

Merged

yuwata closed this as completed in #27579 May 8, 2023

YHNdnzj mentioned this issue May 11, 2023

core: only refuse Type=dbus service enqueue if dbus has pending stop job #27605

Merged

jamacku mentioned this issue Mar 28, 2024

Backport support for %systemd_postun_with_reload redhat-plumbers/systemd-rhel9#250

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Disable service activation from dbus-broker while dbus-broker.service is deactivating #26799

Disable service activation from dbus-broker while dbus-broker.service is deactivating #26799

Geass-LL commented Mar 14, 2023

poettering commented Mar 15, 2023

poettering commented Mar 15, 2023

Disable service activation from dbus-broker while dbus-broker.service is deactivating #26799

Disable service activation from dbus-broker while dbus-broker.service is deactivating #26799

Comments

Geass-LL commented Mar 14, 2023

Component

Is your feature request related to a problem? Please describe

Describe the solution you'd like

Describe alternatives you've considered

The systemd version you checked that didn't have the feature you are asking for

poettering commented Mar 15, 2023

poettering commented Mar 15, 2023