Bug#1056137: systemd: downgrading systemd packages kills off the desktop environment
Am 28.02.24 um 22:22 schrieb Richard Lewis: On Wed, 28 Feb 2024 18:37:41 +0100 Michael Biebl wrote: On Fri, 17 Nov 2023 14:40:05 +0100 Christoph Anton Mitterer wrote: Package: systemd Version: 255~rc2-1 Because of #1056135 I was downgradin systemd/udev packages to 254.5-1. While apt was still running, this causes the whole desktop environment (I use cinnamon) to be killed (and all processes in it ;-) ). My guess is, that the failures you encountered are due to the following change in v255: """ Service Manager: * The way services are spawned has been overhauled. I couldnt follow the bit i deleted, and this maybe jumping to conclusions: are there any implications for upgrading to/after 255 within a desktop environment? should something be said in the release-notes? No, upgrades should work fine. That said, the usual recommendations for dist-upgrades apply https://www.debian.org/releases/stable/amd64/release-notes/ch-upgrading.en.html#upgrade-preparations I.e. it is generally not recommended to dist-upgrade from within a desktop session although usually it works. OpenPGP_signature.asc Description: OpenPGP digital signature
Bug#1056137: systemd: downgrading systemd packages kills off the desktop environment
On Wed, 28 Feb 2024 18:37:41 +0100 Michael Biebl wrote: > On Fri, 17 Nov 2023 14:40:05 +0100 Christoph Anton Mitterer > wrote: > > Package: systemd > > Version: 255~rc2-1 > > Because of #1056135 I was downgradin systemd/udev packages to 254.5-1. > > While apt was still running, this causes the whole desktop environment > > (I use cinnamon) to be killed (and all processes in it ;-) ). > My guess is, that the failures you encountered are due to the following > change in v255: > > """ > Service Manager: > > * The way services are spawned has been overhauled. I couldnt follow the bit i deleted, and this maybe jumping to conclusions: are there any implications for upgrading to/after 255 within a desktop environment? should something be said in the release-notes?
Bug#1056137: systemd: downgrading systemd packages kills off the desktop environment
Control: severity -1 wishlist Control: tags -1 + help Hi Christoph On Fri, 17 Nov 2023 14:40:05 +0100 Christoph Anton Mitterer wrote: Package: systemd Version: 255~rc2-1 Severity: important Hey. Because of #1056135 I was downgradin systemd/udev packages to 254.5-1. While apt was still running, this causes the whole desktop environment (I use cinnamon) to be killed (and all processes in it ;-) ). Tried it twice, happened twice. I acknowledge that not being able to downgrade is a nuisance. systemd is not special in that regard though. Quite a few packages that I now need to convert their on-disk-files on upgrades to a new format which is not easily reversible. None of those packages have explicit maintainer scripts code though, which would prevent a downgrade. So we do not plan to add maintainer scripts code in systemd either. My guess is, that the failures you encountered are due to the following change in v255: """ Service Manager: * The way services are spawned has been overhauled. Previously, a process was forked that shared all of the manager's memory (via copy-on-write) while doing all the required setup (e.g.: mount namespaces, CGroup configuration, etc.) before exec'ing the target executable. This was problematic for various reasons: several glibc APIs were called that are not supposed to be used after a fork but before an exec, copy-on-write meant that if either process (the manager or the child) touched a memory page a copy was triggered, and also the memory footprint of the child process was that of the manager, but with the memory limits of the service. From this version onward, the new process is spawned using CLONE_VM and CLONE_VFORK semantics via posix_spawn(3), and it immediately execs a new internal binary, systemd-executor, that receives the configuration to apply via memfd, and sets up the process before exec'ing the target executable. The systemd-executor binary is pinned by file descriptor by each manager instance (system and users), and the reference is updated on daemon-reexec - it is thus important to reexec all running manager instances when the systemd-executor and/or libsystemd* libraries are updated on the filesystem. """ This is just a guess though. There is only so much we can do as Debian systemd team. If that issue is important to you, please consider investigating this further and providing patches, ideally via a MR on salsa. Michael OpenPGP_signature.asc Description: OpenPGP digital signature
Bug#1056137: systemd: downgrading systemd packages kills off the desktop environment
On Fri, 2023-11-17 at 15:37 +0100, Michael Biebl wrote: > downgrades are not officially supported by Debian. Sure... and if it's not fixable... well then it's not. But at least it would be better then to abort the downgrade if it's detected that e.g. a DE is running. In my case it didn't matter but people may have important/unsaved data open. And maybe there is just some accidental restart of dbus or so involved (that usually kills of the DE, too). Cheers, Chris.
Bug#1056137: systemd: downgrading systemd packages kills off the desktop environment
Am 17.11.23 um 15:31 schrieb Christoph Anton Mitterer: Control: tags -1 - moreinfo Hey Luca. On Fri, 2023-11-17 at 14:03 +, Luca Boccassi wrote: Please attach the journal from around the time where the installation was happening Please see the attached file. Also I just remembered, that with 255~rc2-1, and after it happened that downgrading killed my DE session... I logged into Cinnamon again, and when *then* pressing the power button, it wasn't even like in #1056135, that *only* the Hibernation button was missing, but *no* pop-up dialog (with at least Suspend, Cancel, Restart, Shutdown) showed up, and it went straight without any further confirmation into shutdown. Just a word of warning: downgrades are not officially supported by Debian. They might just work most of the time for more trivial packages, but often they don't (e.g. because data structures have changed that are converted on upgrades but not on downgrades). Regards, Michael OpenPGP_signature.asc Description: OpenPGP digital signature
Bug#1056137: systemd: downgrading systemd packages kills off the desktop environment
Control: tags -1 moreinfo On Fri, 17 Nov 2023 14:40:05 +0100 Christoph Anton Mitterer wrote: > Package: systemd > Version: 255~rc2-1 > Severity: important > > Hey. > > Because of #1056135 I was downgradin systemd/udev packages to 254.5- 1. > While apt was still running, this causes the whole desktop environment > (I use cinnamon) to be killed (and all processes in it ;-) ). > > Tried it twice, happened twice. Please attach the journal from around the time where the installation was happening -- Kind regards, Luca Boccassi signature.asc Description: This is a digitally signed message part
