[boost] Permissions in boost::iostreams::mapped_file output

Boost folks, Working with mapped_files in a project, I recently discovered that the files were being written to disk with unexpected permissions on the linux systems. I discussed this further in a pull request here: https://github.com/boostorg/iostreams/pull/2 Is this the proper avenue for making such a contribution? If not, where can I go to get started. Thanks, Patrick