Multiple btrfs root subvolumes?

[Justin Vallon]

I am wondering whether Grub2 has any btrfs support for multiple root 
subvolumes.  It appears it might be able to handle writing a grub.cfg 
that would reboot into the current root partition if the partition is 
btrfs (though, not sure).

The grub-mkconfig code seems confused by btrfs:

1) It assumes a device has a single filesystem
2) It steps through devices, then maps device to mount point
3) 30_os-prober has some code for btrfs from os-prober output, but I 
don't see where os-prober will generate such entries

It would be nice if it would be able to generate a grub.cfg that could 
boot into any subvolume that was bootable:

1) Recognize btrfs filesystem
2) Temp mount subvol=. if not already mounted
3) Run os-detector on each subvol

Does this not work?

--
-Justin
JustinVallon@gmail.com