The code-owners plugin provides support to define code owners for directories and files in a repository/branch.
If the code-owners plugin is enabled, changes can only be submitted if all touched files are covered by approvals from code owners.
An overview of the supported features can be found here.
IMPORTANT: Using the code-owners plugin is recommended only for repositories that contain files / folders that are owned by different users. If this is not the case, and all files / folders in the repository are owned by the same users plain Gerrit permissions should be preferred instead.
IMPORTANT: Before installing/enabling the plugin, or enabling the code owners functionality for further projects, follow the instructions from the setup guide.