1 files changed, 61 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/ext/disklayout/dirent_new.go b/pkg/sentry/fsimpl/ext/disklayout/dirent_new.go
new file mode 100644
index 000000000..29ae4a5c2
--- /dev/null
+++ b/pkg/sentry/fsimpl/ext/disklayout/dirent_new.go
@@ -0,0 +1,61 @@
+// Copyright 2019 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 disklayout
+
+import (
+	"fmt"
+
+	"gvisor.dev/gvisor/pkg/sentry/fs"
+)
+
+// DirentNew represents the ext4 directory entry struct. This emulates Linux's
+// ext4_dir_entry_2 struct. The FileName can not be more than 255 bytes so we
+// only need 8 bits to store the NameLength. As a result, NameLength has been
+// shortened and the other 8 bits are used to encode the file type. Use the
+// FileTypeRaw field only if the SbDirentFileType feature is set.
+//
+// Note: This struct can be of variable size on disk. The one described below
+// is of maximum size and the FileName beyond NameLength bytes might contain
+// garbage.
+type DirentNew struct {
+	InodeNumber  uint32
+	RecordLength uint16
+	NameLength   uint8
+	FileTypeRaw  uint8
+	FileNameRaw  [MaxFileName]byte
+}
+
+// Compiles only if DirentNew implements Dirent.
+var _ Dirent = (*DirentNew)(nil)
+
+// Inode implements Dirent.Inode.
+func (d *DirentNew) Inode() uint32 { return d.InodeNumber }
+
+// RecordSize implements Dirent.RecordSize.
+func (d *DirentNew) RecordSize() uint16 { return d.RecordLength }
+
+// FileName implements Dirent.FileName.
+func (d *DirentNew) FileName() string {
+	return string(d.FileNameRaw[:d.NameLength])
+}
+
+// FileType implements Dirent.FileType.
+func (d *DirentNew) FileType() (fs.InodeType, bool) {
+	if inodeType, ok := inodeTypeByFileType[d.FileTypeRaw]; ok {
+		return inodeType, true
+	}
+
+	panic(fmt.Sprintf("unknown file type %v", d.FileTypeRaw))
+}