Btrfs

BTRFS-ism: The “Corrupt Leaf” Mystery – or when newer kernels turn strict

TL;DR if you are into a longer version including how to debug check BTRFS-ism: Metadata “Evolution” – the story so far!

If you’ve moved a BTRFS drive from an older system (like Ubuntu 20.04) to a cutting-edge kernel (like 6.15) and suddenly hit a “can’t read superblock” on mounting your volume, you aren’t alone. Even weirder: the drive still works perfectly on the old system.

BTRFS-ism: Metadata “Evolution” – Your Backup Drive is Dead!

TL;DR if you are looking for a quick solution check BTRFS-ism: The “Corrupt Leaf” Mystery!

The Scenario

If you didn’t know what BTRFS-ism is: I found myself stuck today when I plugged in my external USB backup drive:

$ sudo mount /dev/mapper/luks-5c3931a2-4333-415f-8e58-b3b4d728f4d8 /media/backup
mount: /media/backup: can't read superblock on /dev/mapper/luks-5c3931a2-4333-415f-8e58-b3b4d728f4d8.

LUKS was opened successfully, but BTRFS refused to mount. Yes, it is BTRFS – again :(