Looking at the history of the file (http://pkgs.fedoraproject.org/cgit/rpms/hardlink.git/log/hardlink.c ) I can't really say why it was restricting to 7 characters. It might be for the original source of hardlink.c (which was shipped with kernel) to prevent broken filenames with FAT filesystems. To attach a patch, just click on "add an attachmament" on the bug report page.