[CentOS] btrfs in centos 6

I played with btrfs in centos 6.3 and it seemed to mostly work. Now
I'm building some new systems with 6.5, where I'd like to have some
data disks using btrfs - not the system disk. I can create and fiddle
with btrfs filesystems just fine, but attempting to mount them
produces an oops. Surfing the Internets has not enlightened me.

I installed btrfs-progs, and can modprobe btrfs, no problem.

This warning appears:
[root at h-248-254 ~]# btrfsck /dev/sdb
failed to open /dev/btrfs-control skipping device registration

Which I see I can fix with
[root at h-248-254 ~]# mknod /dev/btrfs-control c 10 234
[root at h-248-254 ~]# btrfsck /dev/sdb
checking extents
...

which makes me think that I'm missing some udev rules? And then for
the mount oops I only have a photo, but the call chain is

...
bad_area
__do_page_fault
call_rcu_sched
call_rcu
do_page_fault
page_fault
selinux_set_mnt_opts
superblock_doinit
deactiviate_locked_super
selinux_sb_kern_mount
security_sb_kern_mount
vfs_kern_mount
do_kern_mount

I'm not 100% sure this hardware is OK ... but I can do lots of stuff
with the btrfs progs and never see any problems.

Can anyone who has this working give me a clue? Thanks.

-- greg