861f46b221
Some graphdrivers are Differs and type assertions are made in various places throughout the project. Differ offers some convenience in generating/applying diffs of filesystem layers but for most graphdrivers another code path is taken. This patch brings all of the logic related to filesystem diffs in one place, and simplifies the implementation of some common types like Image, Daemon, and Container. Signed-off-by: Josh Hawn <josh.hawn@docker.com> Upstream-commit: dee6b481fe0da1d845261ffff2e610fb05898d3c Component: engine