Yeah, if I were Oracle I'd definitely throw away a native Linux filesystem in the late stages of development and start porting some goofy jock-ware from an alien kernel. But I'm not Oracle and so they're foolishly carrying on with their insane scheme: http://article.gmane.org/gmane.comp.file-systems.btrfs/2880
"""Theodore Ts'o, developer of ext3 and ext4 filesystems, said that Btrfs “has a number of the same design ideas that Reiser4 had” and that “the filesystem format has support for some advanced features that are designed to leapfrog ZFS.”""