/usr/src/linux-headers-3.19.0-30-generic/mm is in linux-headers-3.19.0-30-generic 3.19.0-30.34~14.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/src/linux-headers-3.19.0-30-generic/../linux-headers-3.19.0-30/mm