Create mount destinations if they don't exist.

This moves code from libcontainer to libminijail so that mounts made in
the container don't have to exist before hand.
This feature is useful when creating a tmpfs mount and bind mounting
a file into that tmpfs, as in the test example.

BUG=none
TEST=minijail0 -m "0 1000 1" -M "0 1000 1" -v -C / \
    -k tmpfs,/tmp/asdf,tmpfs -b /dev/null,/tmp/asdf/null,1 /bin/bash
    Also added test case to security_Minijail0

Change-Id: Ie2601ee24f5fa9440f26ebc31c4640ada5a3ef12
Signed-off-by: Dylan Reid <dgreid@chromium.org>
1 file changed