btrfs-progs: balance start with convert does not fork in background

[Menion <menion@xxxxxxxxx>]

Hi all

Is it normal that a command like:

btrfs balance start -mconvert=raid1 /array/mount/point

Does not fork in background? I have tried this for converting metadata
from RAID5 to RAID1 but it did not go in background, even if in
another shell brtfs balance status /array/mount/point reported the
status correctly

Bye