Add cimfs differ and snapshotter

Details about CimFs project are discussed in #8346

Signed-off-by: Amit Barve <ambarve@microsoft.com>

vendor/github.com/Microsoft/hcsshim/internal/hcs/process.go

@@ -63,7 +63,7 @@ func (process *Process) SystemID() string {
 }
 
 func (process *Process) processSignalResult(ctx context.Context, err error) (bool, error) {
-	switch err {
+	switch err { //nolint:errorlint
 	case nil:
 		return true, nil
 	case ErrVmcomputeOperationInvalidState, ErrComputeSystemDoesNotExist, ErrElementNotFound:

vendor/github.com/Microsoft/hcsshim/internal/hcs/schema2/layer.go

@@ -9,6 +9,13 @@
 
 package hcsschema
 
+type FileSystemFilterType string
+
+const (
+	UnionFS FileSystemFilterType = "UnionFS"
+	WCIFS   FileSystemFilterType = "WCIFS"
+)
+
 type Layer struct {
 	Id string `json:"Id,omitempty"`
 

vendor/github.com/Microsoft/hcsshim/internal/hcs/schema2/registry_hive.go

@@ -0,0 +1,13 @@
+package hcsschema
+
+// NOTE: manually added
+
+type RegistryHive string
+
+// List of RegistryHive
+const (
+	RegistryHive_SYSTEM   RegistryHive = "System"
+	RegistryHive_SOFTWARE RegistryHive = "Software"
+	RegistryHive_SECURITY RegistryHive = "Security"
+	RegistryHive_SAM      RegistryHive = "Sam"
+)

vendor/github.com/Microsoft/hcsshim/internal/hcs/schema2/registry_key.go

@@ -10,7 +10,7 @@
 package hcsschema
 
 type RegistryKey struct {
-	Hive string `json:"Hive,omitempty"`
+	Hive RegistryHive `json:"Hive,omitempty"`
 
 	Name string `json:"Name,omitempty"`
 

vendor/github.com/Microsoft/hcsshim/internal/hcs/schema2/registry_value.go

@@ -14,7 +14,7 @@ type RegistryValue struct {
 
 	Name string `json:"Name,omitempty"`
 
-	Type_ string `json:"Type,omitempty"`
+	Type_ RegistryValueType `json:"Type,omitempty"`
 
 	//  One and only one value type must be set.
 	StringValue string `json:"StringValue,omitempty"`

vendor/github.com/Microsoft/hcsshim/internal/hcs/schema2/registry_value_type.go

@@ -0,0 +1,17 @@
+package hcsschema
+
+// NOTE: manually added
+
+type RegistryValueType string
+
+// List of RegistryValueType
+const (
+	RegistryValueType_NONE            RegistryValueType = "None"
+	RegistryValueType_STRING          RegistryValueType = "String"
+	RegistryValueType_EXPANDED_STRING RegistryValueType = "ExpandedString"
+	RegistryValueType_MULTI_STRING    RegistryValueType = "MultiString"
+	RegistryValueType_BINARY          RegistryValueType = "Binary"
+	RegistryValueType_D_WORD          RegistryValueType = "DWord"
+	RegistryValueType_Q_WORD          RegistryValueType = "QWord"
+	RegistryValueType_CUSTOM_TYPE     RegistryValueType = "CustomType"
+)

vendor/github.com/Microsoft/hcsshim/internal/hcs/system.go

@@ -97,7 +97,7 @@ func CreateComputeSystem(ctx context.Context, id string, hcsDocumentInterface in
 	events, err := processAsyncHcsResult(ctx, createError, resultJSON, computeSystem.callbackNumber,
 		hcsNotificationSystemCreateCompleted, &timeout.SystemCreate)
 	if err != nil {
-		if err == ErrTimeout {
+		if errors.Is(err, ErrTimeout) {
 			// Terminate the compute system if it still exists. We're okay to
 			// ignore a failure here.
 			_ = computeSystem.Terminate(ctx)
@@ -238,7 +238,7 @@ func (computeSystem *System) Shutdown(ctx context.Context) error {
 
 	resultJSON, err := vmcompute.HcsShutdownComputeSystem(ctx, computeSystem.handle, "")
 	events := processHcsResult(ctx, resultJSON)
-	switch err {
+	switch err { //nolint:errorlint
 	case nil, ErrVmcomputeAlreadyStopped, ErrComputeSystemDoesNotExist, ErrVmcomputeOperationPending:
 	default:
 		return makeSystemError(computeSystem, operation, err, events)
@@ -259,7 +259,7 @@ func (computeSystem *System) Terminate(ctx context.Context) error {
 
 	resultJSON, err := vmcompute.HcsTerminateComputeSystem(ctx, computeSystem.handle, "")
 	events := processHcsResult(ctx, resultJSON)
-	switch err {
+	switch err { //nolint:errorlint
 	case nil, ErrVmcomputeAlreadyStopped, ErrComputeSystemDoesNotExist, ErrVmcomputeOperationPending:
 	default:
 		return makeSystemError(computeSystem, operation, err, events)
@@ -279,7 +279,7 @@ func (computeSystem *System) waitBackground() {
 	span.AddAttributes(trace.StringAttribute("cid", computeSystem.id))
 
 	err := waitForNotification(ctx, computeSystem.callbackNumber, hcsNotificationSystemExited, nil)
-	switch err {
+	switch err { //nolint:errorlint
 	case nil:
 		log.G(ctx).Debug("system exited")
 	case ErrVmcomputeUnexpectedExit: