As we released this in the beta channel, and it is a nice feature that our users love,
backporting this to 4.4 so we don't have to revert it or conditionally behave differently.
This is upstream Linux commits
- 9a08c352d05305ca7651540c3b107da1e4e1f40b fs: add filp_clone_open API
- 948b701a607f123df92ed29084413e5dd8cda2ed binfmt_misc: add persistent opened binary handler for containers
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
