This file is indexed.

/usr/src/linux-headers-4.15.0-13-generic/zfs is in linux-headers-4.15.0-13-generic 4.15.0-13.14~16.04.1.

This file is owned by root:root, with mode 0o777.

It is a symlink to /usr/src/linux-headers-4.15.0-13-generic/../linux-headers-4.15.0-13/zfs