Re: [yocto] ext4 issues with scarthgap .wic image

[Mikko Rapeli <mikko.rapeli@linaro.org>]

Hi,

On Wed, Nov 20, 2024 at 11:37:51AM +0000, tboeckel via lists.yoctoproject.org wrote:
> Hi!
> 
> I am building an image for an iMX8 system and recently upgraded from hardknott to scarthgap. The image (wic.bz2) is created successfully, but after deploying it to an SD card I am not able to resize the partition via resize2fs. resize2fs always tells that the filesystem is using unsupported features.
> 
> After investigating further with gparted I found out that the ext4 partition was created with the C12 feature (orphan_file). I am using Ubuntu 22 and hence use resize2fs 1.46.5. There are some forum which suggest resize2fs 1.47.x as a workaround, but I don't cannot upgrade that easily to Ubuntu 23 or 24 yet.
> 
> I also built another image for an iMX93 system based on mickledore where I experience EXACTLY the same issue. For that system it was sufficient to add this line to conf/local.conf:
> EXTRA_IMAGECMD:ext4 += " -O ^orphan_file"
> 
> After that the created ext4 filesystem was compatible to Ubuntu 22's resize2fs 1.46.5 again.
> 
> Unfortunately this did not help f�r the scarthgap build. No matter what I try, the additional options don't make their way to the call of mkfs.ext4.
> 
> What am I doing wrong and what can I do about that? What is the difference between mickledore and scarthgap in this respect?

I think these kind of changes are expected in yocto major version updates.
If new ext4 etc features would need to be explicitly enabled, then users
and maintainers would be flooded with them. Upstream defaults are better
even if they sometimes are not backwards compatible.

I would not expect yocto tooling to always be compatible with other Linux distros
so I would rather add the resize2fs etc partition resize tooling to the
image itself and resize partition(s) on the target at runtime. This can be
part of the target 'flashing' process. This is IMO more future proof.

Cheers,

-Mikko