The disclosed embodiments disclose techniques for managing a global namespace for a distributed filesystem. Two or more cloud controllers collectively manage distributed filesystem data that is stored in a cloud storage system; the cloud controllers ensure data consistency for the stored data, and each cloud controller caches portions of the distributed filesystem. Furthermore, a global namespace for the distributed filesystem is also split across these cloud controllers, with each cloud controller “owning” (e.g., managing write accesses for) a distinct portion of the global namespace and maintaining a set of namespace mappings that indicate which portion of the namespace is assigned to each cloud controller. During operation, an initial cloud controller receives a request from a client system to access a target file in the distributed system. This initial cloud controller uses the namespace mappings for the global namespace to determine a preferred cloud controller that will handle the request.