bcachefs fsck fails with device too small

[brvtalcake]

Hi, I'm a fresh bcachefs user, which I'm currently installing gentoo on.

Before moving most of my 3 disks to bcachefs (except for ESP/XBOOTLDR, since Limine doesn't read anything else than FAT, and /var, for fast emerge), I kept an XFS partition large enough to hold the archived data I wanted to migrate.

Then, after I moved back my data to the freshly created bcachefs, I deleted the XFS partition, and enlarged the bcachefs one on the device the previous XFS partition was on (with bcachefs device resize).

So, the real issue is : since I enlarged the bcachefs partition, running bcachefs fsck [any option except --kernel] dev1:dev2:dev3 (offline) systematically ends up with :

cannot online: device too small
Running userspace offline fsck
cannot online: device too small

Also something strange : running either userspace online fsck or any in-kernel fsck works fine without complaining about device being too small (although for some reasons I also had a problem with a kworker hanging after a offline bcachefs fsck --kernel --reconstruct_alloc, but is it even related ?)

My bcachefs is comprised of 2 NVMEs, 1 of which is very fast but quite small, that I use as a cache device, and 1 optical SATA HDD ("slow" NVME for metadata, HDD for compressed data)
The LiveCD I use to install gentoo is a classic archiso with kernel Linux archiso 6.11.5-arch1-1

Although I doubt I will remember what I exactly typed to end up having this error, let me know if you have any questions. I would be glad to help !

PS : if someone knows where to find some working code to just mount a multi-device bcachefs root in a dracut-generated initramfs (the dracut module I tried to write didn't want to work so I'm making my own initramfs but it's a tiny bit annoying)