creating new partition has corrupted the disklabel ("bad super block")

Hello

I have recently got an upgrade for my laptop with a 1TB SSD drive.
I successfully managed to install a dual boot between archlinux and
openbsd, both on encrypted partitions.

Everything was fine with both systems, until the final act of the
dual boot which consists in setting a partition for file sharing
between the two operating systems, using encfs on ext2.

Creating this partition in archlinux works fine, but has seemingly
corrupted the disklabel for openbsd : openbsd boots fine until the
disk-checking step comes, whereupon I am informed that the j and k
partitions on the sd1 disklabel are somewhat corrupted:

/dev/sd1k (/home): BAD SUPER BLOCK: MAGIC NUMBER WRONG
/dev/sd1j (/usr/obj): BAD SUPER BLOCK: VALUES IN SUPER BLOCK DISAGREE
WITH THOSE IN LAST ALTERNATE

UNEXPECTED INCONSISTENCY; RUN fsck_ffs MANUALLY

Automatic file system check failed: help!
Enter pathname of shell or RETURN for sh:

(this is an approximate copy of the error messages, I cannot properly
access the system to copy the logs or a full disklabel/fdisk)

How could I solve this ? For now trying a few things with fsck or newfs
didn't work but perhaps I looked in the wrong direction.

Also, this is on an install before the last openbsd 7.0 release.
I don't know how I can upgrade an encrypted install using the usb
medium, but perhaps if I would this would be a way to solve my problem?

Thanks,
--
Sylvain Saboua
from webmail