Hey Ben, Salvatore. Thanks for cherry-picking the bug for unstable.
AFAIU stretch and jessie[-backports] should be affected as well. Shouldn't it go there, too? At least at the upstream mailing list it was said the the bug was introduced around October 2008, which should be roughly kernel 2.6.23. Cheers, Chris.  https://lore.kernel.org/linux-btrfs/cal3q7h599_kdpdfhmrqswnlxktanc7aaqbe+hm6jjpr37us...@mail.gmail.com/