[r222277] Strange GEOM, bsdlabel and ZFS behavior

I have FreeBSD-CURRENT r222277. I try to install ZFS root into MBR
using manual on wiki page.

There is some problem with GEOM and BSD label:

# gpart create -s BSD ada0s1
# gpart add -s 192G -t freebsd-zfs ada0s1
# gpart add -t freebsd-swap ada0s1
#gpart show ada0s1
...

gpart show is work now, but not when I load zfs into memory and try to
add zpool into.

and when I'll boot gpart says 'GEOM: ada0s1a invalid disklabel'


PS: there're too much bsdlabel devices (previous releases gives much
less device nodes (there was no aa, ab, ac, ca, cb)