2 files changed, 75 insertions, 0 deletions
diff --git a/pkg/sentry/fs/ext4/BUILD b/pkg/sentry/fs/ext4/BUILD
new file mode 100644
index 000000000..9df9084c3
--- /dev/null
+++ b/pkg/sentry/fs/ext4/BUILD
@@ -0,0 +1,14 @@
+package(licenses = ["notice"])
+
+load("//tools/go_stateify:defs.bzl", "go_library")
+
+go_library(
+    name = "ext4",
+    srcs = ["fs.go"],
+    importpath = "gvisor.googlesource.com/gvisor/pkg/sentry/fs/ext4",
+    visibility = ["//pkg/sentry:internal"],
+    deps = [
+        "//pkg/sentry/context",
+        "//pkg/sentry/fs",
+    ],
+)
diff --git a/pkg/sentry/fs/ext4/fs.go b/pkg/sentry/fs/ext4/fs.go
new file mode 100644
index 000000000..de5f0ef63
--- /dev/null
+++ b/pkg/sentry/fs/ext4/fs.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 ext4 implements the ext4 filesystem.
+package ext4
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
+)
+
+// filesystem implements fs.Filesystem for ext4.
+//
+// +stateify savable
+type filesystem struct{}
+
+func init() {
+	fs.RegisterFilesystem(&filesystem{})
+}
+
+// FilesystemName is the name under which the filesystem is registered.
+// Name matches fs/ext4/super.c:ext4_fs_type.name.
+const FilesystemName = "ext4"
+
+// Name is the name of the file system.
+func (*filesystem) Name() string {
+	return FilesystemName
+}
+
+// AllowUserMount prohibits users from using mount(2) with this file system.
+func (*filesystem) AllowUserMount() bool {
+	return false
+}
+
+// AllowUserList prohibits this filesystem to be listed in /proc/filesystems.
+func (*filesystem) AllowUserList() bool {
+	return false
+}
+
+// Flags returns properties of the filesystem.
+//
+// In Linux, ext4 returns FS_REQUIRES_DEV. See fs/ext4/super.c
+func (*filesystem) Flags() fs.FilesystemFlags {
+	return fs.FilesystemRequiresDev
+}
+
+// Mount returns the root inode of the ext4 fs.
+func (f *filesystem) Mount(ctx context.Context, device string, flags fs.MountSourceFlags, data string, cgroupsInt interface{}) (*fs.Inode, error) {
+	panic("unimplemented")
+}