systemd-repart very slow creation of partitions with Encrypt=

[jmbaur]

systemd version the issue has been seen with

255.4

Used distribution

NixOS

Linux kernel version used

6.8.9

CPU architectures issue was seen on

x86_64

Component

systemd-repart

Expected behaviour you didn't see

Repart takes a few seconds to partition and format the disk on first boot, then booting continues. I originally saw this issue on the mailing list (https://lists.freedesktop.org/archives/systemd-devel/2023-June/049165.html) and noticed an issue did not also exist on github.

Unexpected behaviour you saw

Repart doesn't finish and booting fails after the timeout is reached for the attempt to find the dm-crypt device for the root partition.

Steps to reproduce the problem

Create a repart config to be used in the initrd with a partition of type "root" with Encrypt=tpm2. I'm unsure if the issue is related to having tpm2 or if it is also present with key-file. I haven't been able to reproduce the issue in a VM, only on real hardware (happens on a laptop with 512GiB disk and also a desktop with 1TiB disk). I'll paste debug logs soon, as the process to get them is destructive without being able to reproduce in a VM.

Additional program output to the terminal or log subsystem illustrating the issue

https://gist.github.com/jmbaur/2a374649d73d9454fe2982773a02cdcc

[poettering]

Hmm, it's the mkfs.btrfs that just hangs. Weird. I'd assume that even on a 500G disk it should be snappy to finish...

No idea what mkfs.btrfs is doing there...