Hello, Please consider including mainline commit da362b09e42ee0bcaf0356afee6078b4f324baff in the next v3.13.y-ckt release. It was included in the mainline tree as of v3.19-rc1. It has been tested and confirmed to resolve http://bugs.launchpad.net/bugs/1541313 .
commit da362b09e42ee0bcaf0356afee6078b4f324baff
Author: Eric W. Biederman <ebied...@xmission.com>
Date: Tue Oct 7 12:19:53 2014 -0700
umount: Do not allow unmounting rootfs.
Sincerely,
Joseph Salisbury
