Implements btrfs usage using a double walking diff and
counting the result. Walking gives the most accurate
count and includes inode usage.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
This mainly fixes Linux vs generic Unix differences, with some
differences between Darwin and Freebsd (which are close bit not
identical). Should make fixing for other Unix platforms easier.
Note there are not yet `runc` equivalents for these platforms;
my current use case is image manipulation for the `moby` tool.
However there is interest in OCI runtime ports for both platforms.
Current status is that MacOS can build and run `ctr`, `dist`
and `containerd` and some operations are supported. FreeBSD 11
still needs some more fixes to continuity for extended attributes.
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
To allow the querying of usage for snapshots, we define a new method on
the snapshotter to query the resources in use by a single snapshot.
Conversely, it can be said that if the snapshot was deleted, the
reported amount of usage would be recovered.
There are few problems with this model in the implementation of btrfs
that need to be worked out. In btrfs, it is hard to resolve the amount
of data usage with the use of quotas but these may report valuables that
are incompatible with the model.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
