Comment 0 for bug 1640823

trusty has a very old util-linux which does not yet know about /dev/loop-control to create arbitrarily many loop devices. This feature was introduced in Linux 3.1 already (i. e. before precise even). This is a showstopper for backporting snappy as that needs a lot of loop mounts.

Support for loop-control got introduced in

$ for i in `seq 20`; do echo $i; sudo losetup --find --show /etc/issue; done

With current trusty's util-linux this will only work for 8 loop devices and then start failing:

losetup: could not find any free loop device

With the proposed version, they should all work.

REGRESSION POTENTIAL: /dev/loop-control and the corresponding util-linux support has exited for a long time without known/major issues, so this should be fairly safe.