Merge 216da0b7 (automated)

1 files changed, 78 insertions, 0 deletions

diff --git a/pkg/sentry/fs/restore.go b/pkg/sentry/fs/restore.go
new file mode 100644
index 000000000..f10168125
--- /dev/null
+++ b/pkg/sentry/fs/restore.go
@@ -0,0 +1,78 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fs
+
+import (
+	"sync"
+)
+
+// RestoreEnvironment is the restore environment for file systems. It consists
+// of things that change across save and restore and therefore cannot be saved
+// in the object graph.
+type RestoreEnvironment struct {
+	// MountSources maps Filesystem.Name() to mount arguments.
+	MountSources map[string][]MountArgs
+
+	// ValidateFileSize indicates file size should not change across S/R.
+	ValidateFileSize bool
+
+	// ValidateFileTimestamp indicates file modification timestamp should
+	// not change across S/R.
+	ValidateFileTimestamp bool
+}
+
+// MountArgs holds arguments to Mount.
+type MountArgs struct {
+	// Dev corresponds to the devname argumnent of Mount.
+	Dev string
+
+	// Flags corresponds to the flags argument of Mount.
+	Flags MountSourceFlags
+
+	// DataString corresponds to the data argument of Mount.
+	DataString string
+
+	// DataObj corresponds to the data interface argument of Mount.
+	DataObj interface{}
+}
+
+// restoreEnv holds the fs package global RestoreEnvironment.
+var restoreEnv = struct {
+	mu  sync.Mutex
+	env RestoreEnvironment
+	set bool
+}{}
+
+// SetRestoreEnvironment sets the RestoreEnvironment. Must be called before
+// state.Load and only once.
+func SetRestoreEnvironment(r RestoreEnvironment) {
+	restoreEnv.mu.Lock()
+	defer restoreEnv.mu.Unlock()
+	if restoreEnv.set {
+		panic("RestoreEnvironment may only be set once")
+	}
+	restoreEnv.env = r
+	restoreEnv.set = true
+}
+
+// CurrentRestoreEnvironment returns the current, read-only RestoreEnvironment.
+// If no RestoreEnvironment was ever set, returns (_, false).
+func CurrentRestoreEnvironment() (RestoreEnvironment, bool) {
+	restoreEnv.mu.Lock()
+	defer restoreEnv.mu.Unlock()
+	e := restoreEnv.env
+	set := restoreEnv.set
+	return e, set
+}