FDE image fails to run e2fsck

Given new incompatible RO and RW features in ext4 that v5.15 kernels support, imho we should SRU backport of e2fsprogs on HWE grounds.

Related debian bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1031622

Status changed to 'Confirmed' because the bug affects multiple users.

Newer releases of Ubuntu can always start making use of new file system feature flags. Looking at all currently supported releases (whether standard or ESM), we have never SRUed e2fsprogs before, it only ever received security updates, so I'd be inclined to not do a backport here either and resolve that in the snap side of things.

Generally for recovery purposes you will be booting an image with an equal or newer version of Ubuntu.

Regarding Dimitri's comment about new kernel feature support in 5.15, that doesn't seem related to this issue, and I'm not sure we should be changing feature flag in a stable release anyhow.

I ran into this bug myself a while ago by doing following: I bought a new NVMe and put it into my laptop. Then I booted a recent Ubuntu live system, created partitions on the NVMe, copied everything from the old to the new, updated entries in /etc/fstab etc. When I rebooted the file system check failed with that error message. I either re-did everything with a Ubuntu jammy live system or hot-replaced fsck in the initramfs by /bin/true and upgraded Ubuntu.

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.

This bug was fixed in the package e2fsprogs - 1.47.0-1ubuntu2

---------------
e2fsprogs (1.47.0-1ubuntu2) mantic; urgency=medium

  * Temporarily disable orphan_file by default, such that fsck from jammy
    can check ext4 created in mantic. Given the new incompat ext4 features
    that v5.15 & hwe kernels support, ideally e2fsprogs 1.47.0 should be
    SRUed into jammy. LP: #2025339

 -- Dimitri John Ledkov <email address hidden> Thu, 29 Jun 2023 10:14:32 +0100