Btrfs burned baby burned!
From the better-filesystem-my-ass-back-to-xfs dept. (5347) (0) by Luis
Well, it only took about 6 months but Btrfs burned me badly. It turns out(Btrfs wiki) that simple copying/rename operations can leave you with zero-length file sizes if your system crash (or you loose power or your disk is buggy).
Even doing btrfsck left my filesystem in bad shape. And now I have no idea which files are corrupted or when did I loose them... what a bad situation. Luckily I have enough backups to figure it out.
Back to XFS, the best file system and only champion.