Comment 7 for bug 2025339

For Debian the metadata_csum_seed and orphan_file features were disabled by default by changing the /etc/mke2fs.conf file.

e2fsprogs (1.47.0-2) unstable; urgency=medium

  * Don't enable metadata_csum_seed and orhpan_file by default (Closes:
    #1031622, #1030939)

 -- Theodore Y. Ts'o <email address hidden> Sat, 04 Mar 2023 22:16:08 -0500

Ubuntu Lunar and Mantic chose to only disable metadata_csum_seed:

e2fsprogs (1.47.0-1ubuntu1) lunar; urgency=low

  * Merge from Debian unstable. Remaining changes:
    - Use 4k blocksize in all ext4 mke2fs.conf stanzas, so lvm migration
      between non-4k PVs and 4k PVs works regardless of the volume size.
  * Disable the metadata_csum_seed feature again, as grub does not yet
    support it (Closes: #866603)

 -- Julian Andres Klode <email address hidden> Fri, 17 Feb 2023 11:58:55 +0100

It should be noted that users are always free to change /etc/mke2fs.conf, since that's a configuration file, and the whole point of that file is to make it easy for distributions and users to customize how they mke2fs should behave. So if you think that Ubuntu Mantic should be able create file systems that can be handled by Jammy, it's just a matter of adjusting the mke2fs.conf file in Mantic.

As far as grub support is concerned, the metadata_csum_seed feature flag is supposed by grub2 (2.06-8) or newer. And grub doesn't care about orphan_file, since it's a COMPAT flag. That is an issue for e2fsck, but not for grub. The question was always whether a distribution supports creating a file system that can be (a) mounted and/or (b) fsck'ed by an older distribution, and if so, for how many versions back. That's not something for which people of good will can disagree, which is why it can be made configurable.