Error in linux-2.6.37-git5 in btrfs in ctree.c

Hello,

There is an error in here:

In file included from fs/btrfs/ctree.c:21:
fs/btrfs/ctree.h:1003: error: field ‘super_kobj’ has incomplete type fs/btrfs/ctree.h:1074: error: field ‘root_kobj’ has incomplete type

Kernel fails to build. linux-2.6.37-git5

"Wiedza to władza. Ale niewiedza, niestety, nie oznacza jeszcze
braku władzy." Niels Bohr
NP: Patrick O'Hearn - Gradual Understanding
NB: 2.6.37-next-20110110