This Page lists problems one might face when trying btrfs, this are not really bugs but moslty inconveniences about things not yet implemented, or yet undocumented design decisions.
Please add new things below, don't forget to add a comment on which version you observed this.
- mount -o nodatacow also disables compression
- Using mkfs.btrfs -l and -n for sizes other than 4096 is not supported
- Snapshots and subvolumes cannot yet be removed (scheduled to be fixed in 2.6.32)