That is only partially true. btrfs was founded by Chris Mason before he joined Oracle. They simply let him continue hacking on it. He left Oracle in June of last year and works at Fusion IO. I'm sure Oracle has someone hacking on btrfs, but no one there was seriously pushing it (that I'm aware of) other than Chris Mason.
Do you have any evidence of this? I've tried to corroborate it and from what I can tell Chris Mason himself is quoted as saying he started it shortly after joining Oracle. Additionally Oracle seems to be pretty involved with btrfs and has devoted a lot of resources.
