Jens, I am running the latest 4.19 kernel. When I mount a disk image using option 'loop' in /etc/fstab, it mounts just fine. When I un-mount the loopback device, lsof verifies that nothing else is using it. However, losetup -d will not free the device. Also, the reference counts in lsmod show 2 references for the one loopback device. Where should I start debugging? /usr/src/linux.stable # losetup NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE DIO LOG-SEC /dev/loop0 0 0 1 0 /mnt/images0/i486.img 0 512 /usr/src/linux.stable # lsmod | grep loop loop 24576 2 - Matthew Whitehead
