As a recap, the zone concept has severe limitations including renaming and nested configuration. Those limitations are valid in encryption for security reasons and it doesn't make sense to carry them over in EC.
This JIRA aims to store EC schema and cell size on INodeFile level. For simplicity, we should first implement it as an xattr and consider memory optimizations (such as moving it to file header) as a follow-on. We should also disable changing EC policy on a non-empty file / dir in the first phase.