I was reluctant to take this project, knowing well I would end up deleting nearly all existing code I would have to touch, all while having just mediocre skill writing its successor, if it ever becomes one.
I can no longer escape from this project, nor do have I will to.
A kernel was released that changed how the hash value got computed for casefolded filenames. (used for better windows compatibility) That kernel then went into production. This unfortunately split some file-systems that supported this into two incompatible versions, breaking the kernel rule 1.
There might now exist file-systems were created/modified with this bug present that the old/fixed kernels can’t understand.