Bug#1102160: upgrade-reports: Bookworm to Trixie [amd64][EFI] initramfs unpacking failed invalid magic at start of compressed archive

[Pascal Hambourg]

On 16/04/2025 at 15:51, Martin-Éric Racine wrote:
> ke 16.4.2025 klo 15.41 Pascal Hambourg (pascal at plouf.fr.eu.org) kirjoitti:
>> On 16/04/2025 at 13:38, Martin-Éric Racine wrote:
>>>
>>> As the attached screenshot shows, 'fuseblk' seemingly doesn't know
>>> anything about the 'subvol' option for btrfs, which is what causes the
>>> failure to mount root. As to whether this implies a GRUB or Linux
>>> module, I wouldn't know.
>>
>> The failure has nothing to do with fuse.
>> I guess the kernel tries to mount the root filesystem with fuseblk as a
>> last resort *after* the initramfs unpacking failure because it is the
>> only built-in driver, all other block device/filesystem drivers being
>> modules in the initramfs.
> 
> Shouldn't a built-in autofs handle that part?

I am not sure what you mean by "autofs". AFAIK autofs is an on-demand 
mount feature, so irrelevant for the root filesystem. The kernel image 
(vmlinuz) does not have built-in block/filesystem drivers and needs to 
load the related modules from the initramfs in order to be able to mount 
the root filesystem.

> Anyhow, that line about 'subvol' being an unrecognized option for
> fuseblk is significant.

I don't think so. fuseblk is the wrong filesystem type and the "subvol" 
option is intended for btrfs so it is not surprising that it is not 
recognized.

>> If you start grub shell and load the kernel and initramfs by hand, does
>> it show an error when loading the initramfs ?
> 
> No error.

There may be some silent data corruption when grub reads the initramfs.
Can you test with the initramfs on another filesystem type (fat, ext4) ?
Can you test with grub for BIOS/legacy boot ?