As recently as 2016 I experienced major problems using `rm` with an intentionally-filled btrfs (and current Linux kernel at the time), and per my notes, it was

As recently as 2016 I experienced major problems using `rm` with an intentionally-filled btrfs (and current Linux kernel at the time), and per my notes, it was even mounted as `-o nodatacow`: # rm -f /mnt/data/zero.*.fill rm: cannot remove '/mnt/data/zero.1.fill': No space left on device