repart: support erofs

So, i think "erofs" is probably the better, more modern alternative to
"squashfs". Many of the benefits don't matter too much to us I guess,
but there's one thing that stands out: erofs has a UUID in the
superblock, squashfs has not. Having an UUID in the superblock matters
if the file systems are used in an overlayfs stack, as overlayfs uses
the UUIDs to robustly and persistently reference inodes on layers in
case of metadata copy-up.

Since we probably want to allow such uses in overlayfs as emplyoed by
sysext (and the future syscfg) we probably should ramp up our erofs game
early on. Hence let's natively support erofs, test it, and in fact
mention it in the docs before squashfs even.

1 files changed, 2 insertions, 2 deletions

diff --git a/docs/PORTABLE_SERVICES.md b/docs/PORTABLE_SERVICES.md
index 7a9c7f512d..93c55ac5ee 100644
--- a/docs/PORTABLE_SERVICES.md
+++ b/docs/PORTABLE_SERVICES.md
@@ -223,8 +223,8 @@ images minimal.
 
 If the image is writable, and some of the files or directories that are
 overmounted from the host do not exist yet they will be automatically created.
-On read-only, immutable images (e.g. squashfs images) all files and directories
-to over-mount must exist already.
+On read-only, immutable images (e.g. `erofs` or `squashfs` images) all files
+and directories to over-mount must exist already.
 
 Note that as no new image format or metadata is defined, it's very
 straightforward to define images than can be made use of in a number of