/usr/ is in libjack-jackd2-dev 1.9.9.5+20130622git7de15e7a-1ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/
/usr/include/jack/
/usr/share/
/usr/share/doc/
/usr/share/doc/libjack-jackd2-dev/
/usr/include/jack/midiport.h
/usr/include/jack/jslist.h
/usr/include/jack/weakjack.h
/usr/include/jack/systemdeps.h
/usr/include/jack/net.h
/usr/include/jack/ringbuffer.h
/usr/include/jack/jack.h
/usr/include/jack/statistics.h
/usr/include/jack/session.h
/usr/include/jack/transport.h
/usr/include/jack/control.h
/usr/include/jack/thread.h
/usr/include/jack/intclient.h
/usr/include/jack/weakmacros.h
/usr/include/jack/types.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/jack.pc
/usr/share/doc/libjack-jackd2-dev/copyright
/usr/lib/x86_64-linux-gnu/libjackserver.so
/usr/lib/x86_64-linux-gnu/libjacknet.so
/usr/lib/x86_64-linux-gnu/libjack.so
/usr/share/doc/libjack-jackd2-dev/README.gz
/usr/share/doc/libjack-jackd2-dev/TODO
/usr/share/doc/libjack-jackd2-dev/changelog.Debian.gz