Perhaps it is already known, but e2fsprogrs in backports is not installable due to broken dependencies:
# apt install -t bullseye-backports e2fsprogs e2fsprogs-l10n libext2fs2
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
e2fsprogs : PreDepends: libc6 (>= 2.33) but 2.31-13+deb11u2 is to be installed
libext2fs2 : Depends: libc6 (>= 2.33) but 2.31-13+deb11u2 is to be installed
E: Unable to correct problems, you have held broken packages.
Thank you very much for all your efforts and best regards,
Domenico