Turns out blockdev is actually getting an ioctl error on loop devices when run with --report. I had only tested a few values directly, eg using --getsz. Perhaps that is why this happens?
$ sudo blockdev --report /dev/loop0 RO RA SSZ BSZ StartSec Size Device blockdev: ioctl error on /dev/loop0 $ sudo blockdev --g 60915712 $ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1174098 Title: blockdev doesn't work as reported with loop devices To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/1174098/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
