Options for Git fine-grained access control

[chunlinh]

I want to be able to set up access rights for different Git users or groups based on folder level within one repository.

I've tried this with submodules, but it seemed like if I have a user try to use the command "git submodule update," and any one of the submodules is a clone of a repository the git user does not have access to, the entire "git submodule update" command fails.

Am I doing something wrong with submodules in getting "git fine-grained access control" set up, or is there a better option for doing this?