Bug 2192509

I have (or had) a Fedora 36 installation running an ext4 fs with LVM. I used https://docs.fedoraproject.org/en-US/quick-docs/dnf-system-upgrade/ to upgrade to F38.

The upgrade process did not error, but upon first boot into F38, it kernel panic'ed with an error on blockdev. A member of the Fedora Forums pointed out grub may have made and error and used "mapper/{lvm volume}" instead of "/dev/mapper/{lvm volume}"

I reimaged back to the pre-upgrade state and tried again the following day. This time, it did not kernel panic, but instead hung at "Loading Linux"

Checking the grub config, I could see that this second time, there was no error on the blockdev, but there was no initrd line.

I booted from my F36 config (which was still there since this was a system upgrade), and from inside the F36 installation, I was able to regenerate the grub config using "grub2-mkconfig" and this added the initrd line back. It would appear the system upgrade process did not generate the grub config properly, even though all the config was available.

Reproducible: Always

Steps to Reproduce:
1.F36 with LVM
2.Upgrade using dnf system-upgrade --releasever=38
3.See if it hangs or kernel panics on first boot into 38.
Actual Results:  
First attempt: Kernel panic
Second attempt: Hang on "Loading Linux" (no initrd)

Expected Results:  
Boot into F38 without manual intervention

Original Fedora Forums post: https://forums.fedoraforum.org/showthread.php?330457-F38-Upgrade-quot-Can-t-Open-Blockdev-quot-After-Upgrade