Function hdfsListEncryptionZones 

pub unsafe extern "C" fn hdfsListEncryptionZones(
    fs: hdfsFS,
    numEntries: *mut c_int,
) -> *mut hdfsEncryptionZoneInfo

hdfsEncryptionZoneInfo - Get list of all the encryption zones. hdfsFreeEncryptionZoneInfo should be called to deallocate memory. @param fs The configured filesystem handle. @return Returns a dynamically-allocated array of hdfsEncryptionZoneInfo objects; NULL on error.