I don't know that I'd agree. As much as llvm+clang inspired gcc to improve, ZFS seems like a big part of the inspiration for btrfs. I'm not sure that it hits

I don't know that I'd agree. As much as llvm+clang inspired gcc to improve, ZFS seems like a big part of the inspiration for btrfs. I'm not sure that it hits the whole ZFS feature set, but it's probably a step in that direction.