[st_goliath]

For squashfs there is `tar2sqfs`[1] and `sqfs2tar`[2] (and now also `sqfstar`[3]) that can go from tarball to filesystem and back again.

For ext4, I recently saw a patch set on the mailing list[4].

Not sure about other filesystems tough.

[1] https://manpages.debian.org/unstable/squashfs-tools-ng/tar2s...

[2] https://manpages.debian.org/unstable/squashfs-tools-ng/sqfs2...

[3] https://manpages.debian.org/unstable/squashfs-tools/sqfstar....

[4] https://lore.kernel.org/linux-ext4/20230812150204.462962-2-j...