27c314d5ca09 ("btrfs: factor out init_alloc_chunk_ctl")
4f2bafe8a49e ("btrfs: introduce alloc_chunk_ctl")
cfbb825c7619 ("btrfs: add incompat for raid1 with 3, 4 copies")
47e6f7423b91 ("btrfs: add support for 3-copy replication (raid1c3)")