Fixes for device activation while reloading and switching root#23215
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mwilck wants to merge 2 commits intosystemd:mainfrom
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Fixes for device activation while reloading and switching root#23215mwilck wants to merge 2 commits intosystemd:mainfrom
mwilck wants to merge 2 commits intosystemd:mainfrom
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While the manager is reloaded, the device_monitor socket is kept open; outstanding uevents will be received sooner or later. Thus if a device isn't found during udev enumeration / coldplug, we shouldn't blindly assume it's gone. Possibly the reload operation took place before udev started, or had the time to re-probe previously discovered devices (this matters mainly during boot / coldplug). So if the device actually disappeared, leave it to the outstanding uevent to make this happen in systemd. Fixes systemd#12953.
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When we switch root, it can happen (e.g. because of different udev rules) that a previously plugged device will change to "dead" (SYSTEMD_READY=0). The udev db is actually cleared and will be built up from scratch. We shouldn't activate any mounts or swaps bound to previously "plugged" devices before we actually receive uevents for them indicating they're ready to use. Hence, when we deserialize device units in the "switching root" case (which we can detect from manager->honor_device_enumeration), clear the DEVICE_FOUND_UDEV flag, and map DEVICE_PLUGGED to DEVICE_TENTATIVE. Thus devices which are neither mounted nor used for swap will startup as DEVICE_NOT_FOUND / DEVICE_DEAD, and mounted devices as DEVICE_FOUND_MOUNT / DEVICE_TENTATIVE. This should play well with the logic in device_found_changed(). It is expected that udev coldplug will happen some time after switching root, and that the actual device state will be set by device_dispatch_io(), which will also activate dependent mount units. Fixes systemd#23208.
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See the comments in the code. This is based on the work by Martin Wilck. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215.
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See the comments in the code. This is based on the work by Martin Wilck. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215.
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See the comments in the code. This is based on the work by Martin Wilck. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215.
yuwata
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See the comments in the code. This is based on the work by Martin Wilck. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215.
yuwata
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Apr 30, 2022
See the comments in the code. This is based on the work by Martin Wilck. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215.
yuwata
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See the comments in the code. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215. Co-authored-by: Martin Wilck <mwilck@suse.com>
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The issue systemd#12953 is caused by the following: On switching root, - deserialized_found == DEVICE_FOUND_UDEV | DEVICE_FOUND_MOUNT, - deserialized_state == DEVICE_PLUGGED, - enumerated_found == DEVICE_FOUND_MOUNT, On switching root, most devices are not found by the enumeration process. Hence, the device state is set to plugged by device_coldplug(), and then changed to the dead state in device_catchup(). So the corresponding mount point is unmounted. Later when the device is processed by udevd, it will be changed to plugged state again. The issue systemd#23208 is caused by the fact that generated udev database in initramfs and the main system are often different. So, the two issues have the same root; we should not honor DEVICE_FOUND_UDEV bit in the deserialized_found on switching root. This partially reverts c6e892b. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215. Co-authored-by: Martin Wilck <mwilck@suse.com>
yuwata
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May 1, 2022
The issue systemd#12953 is caused by the following: On switching root, - deserialized_found == DEVICE_FOUND_UDEV | DEVICE_FOUND_MOUNT, - deserialized_state == DEVICE_PLUGGED, - enumerated_found == DEVICE_FOUND_MOUNT, On switching root, most devices are not found by the enumeration process. Hence, the device state is set to plugged by device_coldplug(), and then changed to the dead state in device_catchup(). So the corresponding mount point is unmounted. Later when the device is processed by udevd, it will be changed to plugged state again. The issue systemd#23208 is caused by the fact that generated udev database in initramfs and the main system are often different. So, the two issues have the same root; we should not honor DEVICE_FOUND_UDEV bit in the deserialized_found on switching root. This partially reverts c6e892b. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215. Co-authored-by: Martin Wilck <mwilck@suse.com>
yuwata
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May 1, 2022
The issue systemd#12953 is caused by the following: On switching root, - deserialized_found == DEVICE_FOUND_UDEV | DEVICE_FOUND_MOUNT, - deserialized_state == DEVICE_PLUGGED, - enumerated_found == DEVICE_FOUND_MOUNT, On switching root, most devices are not found by the enumeration process. Hence, the device state is set to plugged by device_coldplug(), and then changed to the dead state in device_catchup(). So the corresponding mount point is unmounted. Later when the device is processed by udevd, it will be changed to plugged state again. The issue systemd#23208 is caused by the fact that generated udev database in initramfs and the main system are often different. So, the two issues have the same root; we should not honor DEVICE_FOUND_UDEV bit in the deserialized_found on switching root. This partially reverts c6e892b. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215. Co-authored-by: Martin Wilck <mwilck@suse.com>
yuwata
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May 2, 2022
The issue systemd#12953 is caused by the following: On switching root, - deserialized_found == DEVICE_FOUND_UDEV | DEVICE_FOUND_MOUNT, - deserialized_state == DEVICE_PLUGGED, - enumerated_found == DEVICE_FOUND_MOUNT, On switching root, most devices are not found by the enumeration process. Hence, the device state is set to plugged by device_coldplug(), and then changed to the dead state in device_catchup(). So the corresponding mount point is unmounted. Later when the device is processed by udevd, it will be changed to plugged state again. The issue systemd#23208 is caused by the fact that generated udev database in initramfs and the main system are often different. So, the two issues have the same root; we should not honor DEVICE_FOUND_UDEV bit in the deserialized_found on switching root. This partially reverts c6e892b. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215. Co-authored-by: Martin Wilck <mwilck@suse.com>
yuwata
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May 11, 2022
The issue systemd#12953 is caused by the following: On switching root, - deserialized_found == DEVICE_FOUND_UDEV | DEVICE_FOUND_MOUNT, - deserialized_state == DEVICE_PLUGGED, - enumerated_found == DEVICE_FOUND_MOUNT, On switching root, most devices are not found by the enumeration process. Hence, the device state is set to plugged by device_coldplug(), and then changed to the dead state in device_catchup(). So the corresponding mount point is unmounted. Later when the device is processed by udevd, it will be changed to plugged state again. The issue systemd#23208 is caused by the fact that generated udev database in initramfs and the main system are often different. So, the two issues have the same root; we should not honor DEVICE_FOUND_UDEV bit in the deserialized_found on switching root. This partially reverts c6e892b. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215. Co-authored-by: Martin Wilck <mwilck@suse.com>
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This is superseded by #23218, right? |
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yes. Closing this. |
yuwata
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May 12, 2022
The issue systemd#12953 is caused by the following: On switching root, - deserialized_found == DEVICE_FOUND_UDEV | DEVICE_FOUND_MOUNT, - deserialized_state == DEVICE_PLUGGED, - enumerated_found == DEVICE_FOUND_MOUNT, On switching root, most devices are not found by the enumeration process. Hence, the device state is set to plugged by device_coldplug(), and then changed to the dead state in device_catchup(). So the corresponding mount point is unmounted. Later when the device is processed by udevd, it will be changed to plugged state again. The issue systemd#23208 is caused by the fact that generated udev database in initramfs and the main system are often different. So, the two issues have the same root; we should not honor DEVICE_FOUND_UDEV bit in the deserialized_found on switching root. This partially reverts c6e892b. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215. Co-authored-by: Martin Wilck <mwilck@suse.com>
bluca
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Jan 27, 2023
The issue systemd#12953 is caused by the following: On switching root, - deserialized_found == DEVICE_FOUND_UDEV | DEVICE_FOUND_MOUNT, - deserialized_state == DEVICE_PLUGGED, - enumerated_found == DEVICE_FOUND_MOUNT, On switching root, most devices are not found by the enumeration process. Hence, the device state is set to plugged by device_coldplug(), and then changed to the dead state in device_catchup(). So the corresponding mount point is unmounted. Later when the device is processed by udevd, it will be changed to plugged state again. The issue systemd#23208 is caused by the fact that generated udev database in initramfs and the main system are often different. So, the two issues have the same root; we should not honor DEVICE_FOUND_UDEV bit in the deserialized_found on switching root. This partially reverts c6e892b. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215. Co-authored-by: Martin Wilck <mwilck@suse.com> (cherry picked from commit 75d7b59)
Werkov
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Nov 1, 2023
The issue systemd#12953 is caused by the following: On switching root, - deserialized_found == DEVICE_FOUND_UDEV | DEVICE_FOUND_MOUNT, - deserialized_state == DEVICE_PLUGGED, - enumerated_found == DEVICE_FOUND_MOUNT, On switching root, most devices are not found by the enumeration process. Hence, the device state is set to plugged by device_coldplug(), and then changed to the dead state in device_catchup(). So the corresponding mount point is unmounted. Later when the device is processed by udevd, it will be changed to plugged state again. The issue systemd#23208 is caused by the fact that generated udev database in initramfs and the main system are often different. So, the two issues have the same root; we should not honor DEVICE_FOUND_UDEV bit in the deserialized_found on switching root. This partially reverts c6e892b. Fixes systemd#12953 and systemd#23208. Replaces systemd#23215. Co-authored-by: Martin Wilck <mwilck@suse.com> (cherry picked from commit 75d7b59) [mwilck: fixes bsc#1137373] [mwilck: fixes bsc#1181658] [mwilck: fixes bsc#1194708] [mwilck: fixes bsc#1195157] [mwilck: fixes bsc#1197570]
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This PR fixes two issues related to device activation.
systemctl reloadrun by some service), devices state could switch from "plugged" to "dead" and back, causing spurious umounts (Devices transition plugged -> dead -> plugged is still not completely fixed #12953)SYSTEMD_READY=0after switching root (because of change udev rules files), systemd might prematurely activate the device even though wasn't ready to use. This happens in multipath setups and can lead to boot failure (Boot to emergency mode if devices are switched to SYSTEMD_READY=0 (multipath scenario) #23208).This PR fixes both issues.
systemd-udev-trigger.servicewill be re-run. The state of plugged devices should be reset toDEVICE_TENTATIVEto avoid premature activation. In the likely case that the device is still plugged, it will be re-detected by udev. This way changed udev properties can be picked up correctly by systemd.More detailed rationale is found in the commit descriptions, comments, and in the two referenced issues.
Fixes #12953
Fixes #23208