Move mount to core/mount

Signed-off-by: Derek McGowan <derek@mcg.dev>

core/mount/temp_unix.go

@@ -0,0 +1,60 @@
+//go:build !windows && !darwin
+
+/*
+   Copyright The containerd 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 mount
+
+import (
+	"os"
+	"sort"
+
+	"github.com/moby/sys/mountinfo"
+)
+
+// SetTempMountLocation sets the temporary mount location
+func SetTempMountLocation(root string) error {
+	err := os.MkdirAll(root, 0700)
+	if err != nil {
+		return err
+	}
+	// We need to pass canonicalized path to mountinfo.PrefixFilter in CleanupTempMounts
+	tempMountLocation, err = CanonicalizePath(root)
+	return err
+}
+
+// CleanupTempMounts all temp mounts and remove the directories
+func CleanupTempMounts(flags int) (warnings []error, err error) {
+	mounts, err := mountinfo.GetMounts(mountinfo.PrefixFilter(tempMountLocation))
+	if err != nil {
+		return nil, err
+	}
+
+	// Make the deepest mount be first
+	sort.Slice(mounts, func(i, j int) bool {
+		return len(mounts[i].Mountpoint) > len(mounts[j].Mountpoint)
+	})
+	for _, mount := range mounts {
+		if err := UnmountAll(mount.Mountpoint, flags); err != nil {
+			warnings = append(warnings, err)
+			continue
+		}
+		if err := os.Remove(mount.Mountpoint); err != nil {
+			warnings = append(warnings, err)
+		}
+	}
+	return warnings, nil
+}