According to the documentation for Go package time, `time.Ticker` and
`time.Timer` are uncollectable by garbage collector finalizers. They
leak until otherwise stopped. This commit ensures that all remaining
instances are stopped upon departure from their relative scopes.
Allow mount volume operations to run in parallel for non-attachable
volume plugins.
Allow unmount volume operations to run in parallel for all volume
plugins.
Modify attach/detach controller to keep track of volumes to report
attached in Node VolumeToAttach status.
Modify kubelet volume manager to wait for volume to show up in Node
VolumeToAttach status.
Implement exponential backoff for errors in volume manager and attach
detach controller
Automatic merge from submit-queue
Add specific error type for "operation already exists" error.
PersistentVolume controller needs to know why scheduling a new operation has failed - if the operation was already running or some other error happened.
PersistentVolume controller needs to know why scheduling a new operation has
failed - if the operation was already running or some other error happened.