grub-probe detects ext4 wronly as ext2

[Felix Zielcke]

Hello,

I reported this already on Debian as #488235

grub-probe -t fs shows ext2 for a filesystem created with e2fsprogs 1.41WIP 
from Debian experimental
with extent and flex_bg
I didn't get grub-probe working with the loopback device even though I added 
it to device.map it still complained.
The attached image is a 10 mb ext4 made with mkfs.ext4 without any special 
options just the extent and flex_bg features enabled by mke2fs.conf
If I make that on a 100 MB Disk in VMware grub-probe -t fs shows ext2 so I 
think it shouldn't be different on that 10 MB file

ext4.img.bz2
Description: Binary data