This moves both the Mount type and mountinfo into a single mount
package.
This also opens up the root of the repo to hold the containerd client
implementation.
Signed-off-by: Michael Crosby <crosbymichael@gmail.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>
Two test cases added
- Prepare, Stat on new layer, should return Active layer.
- Prepare & Commit , Stat on new layer, should return Committed layer
Signed-off-by: Kunal Kushwaha <kushwaha_kunal_v7@lab.ntt.co.jp>
After receiving feedback on the `snapshot.Driver` interface, it was
found that the behavior of active and committed snapshots was confusing.
We attempt to clean this up by doing the following:
1. Define the concept of "active" and "committed" snapshots and their
lifecycle relationship. Active snapshots can be created from a parent.
Committed snapshots can only be created from active snapshots.
2. Only committed snapshots can be a parent.
3. Unify the keyspace of snapshots. For common operations, such as
removal and stat, we only have a single method that works for both
active and committed snapshots. For methods that take one or the other,
the restriction is called out. `Remove` and `Delete` are consolidated
for this purpose.
4. Define the `Info` data type to include name, parent, kind and
readonly state. This allows us to collect `Exists` and `Parent` into a
single method `Stat` and simplifies the `Walk` method, eliding `Active`.
5. The `Driver` has been renamed to `Snapshotter` due to the overuse of
the term `Driver`.
Effectively, we now have snapshots that are either active or committed.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
