60 lines
1.7 KiB
Go
60 lines
1.7 KiB
Go
// +build linux
|
|
|
|
/*
|
|
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 archive
|
|
|
|
import (
|
|
"archive/tar"
|
|
"os"
|
|
"path/filepath"
|
|
"strings"
|
|
|
|
"golang.org/x/sys/unix"
|
|
)
|
|
|
|
// AufsConvertWhiteout converts whiteout files for aufs.
|
|
func AufsConvertWhiteout(_ *tar.Header, _ string) (bool, error) {
|
|
return true, nil
|
|
}
|
|
|
|
// OverlayConvertWhiteout converts whiteout files for overlay.
|
|
func OverlayConvertWhiteout(hdr *tar.Header, path string) (bool, error) {
|
|
base := filepath.Base(path)
|
|
dir := filepath.Dir(path)
|
|
|
|
// if a directory is marked as opaque, we need to translate that to overlay
|
|
if base == whiteoutOpaqueDir {
|
|
// don't write the file itself
|
|
return false, unix.Setxattr(dir, "trusted.overlay.opaque", []byte{'y'}, 0)
|
|
}
|
|
|
|
// if a file was deleted and we are using overlay, we need to create a character device
|
|
if strings.HasPrefix(base, whiteoutPrefix) {
|
|
originalBase := base[len(whiteoutPrefix):]
|
|
originalPath := filepath.Join(dir, originalBase)
|
|
|
|
if err := unix.Mknod(originalPath, unix.S_IFCHR, 0); err != nil {
|
|
return false, err
|
|
}
|
|
// don't write the file itself
|
|
return false, os.Chown(originalPath, hdr.Uid, hdr.Gid)
|
|
}
|
|
|
|
return true, nil
|
|
}
|