This moves Driver.Size() to Differ.DiffSize(), removing the empty
implementations in devmapper and dummy, and renaming the one in aufs.
Then we fall back to a container.Changes() implementation in the non-aufs
case.
Upstream-commit: 5d76681c3d0cbb744205a397420603ce029ce754
Component: engine
This code was duplicated in two places, one which was unused. This
syncs the code and removes the unused version.
Upstream-commit: d69a6a20f0b6657821638ee591920d071a784b0e
Component: engine
This replaces the current version with the latest version from the
dm branch. Advantages in this version:
We only scan each directory tree once, which means less i/o and less chance
of container changes inbetween the two scans causing inconsistencies.
We avoid comparing some fields for change detection:
* Inode
* size-in-blocks
These can change during a copy operation (e.g. in the dummy backend)
without needing to actually reflect a change in content or metadata.
* Ctime
Any copy operation will create a new Ctime value, and there is no
API to change it to the "source" value.
* size for directories
The size of a directory doesn't have to be the same just because you
recreated the same content as another director. Internal details in
the filesystem may make these different with no "real" change.
Upstream-commit: b6ef4bc9521346dc5066d71821c6cadfbeced9d3
Component: engine
