3 files changed, 376 insertions, 49 deletions
diff --git a/pkg/sentry/fsimpl/overlay/BUILD b/pkg/sentry/fsimpl/overlay/BUILD
deleted file mode 100644
index ed730e215..000000000
--- a/pkg/sentry/fsimpl/overlay/BUILD
+++ /dev/null
@@ -1,49 +0,0 @@
-load("//tools:defs.bzl", "go_library")
-load("//tools/go_generics:defs.bzl", "go_template_instance")
-
-licenses(["notice"])
-
-go_template_instance(
-    name = "fstree",
-    out = "fstree.go",
-    package = "overlay",
-    prefix = "generic",
-    template = "//pkg/sentry/vfs/genericfstree:generic_fstree",
-    types = {
-        "Dentry": "dentry",
-    },
-)
-
-go_library(
-    name = "overlay",
-    srcs = [
-        "copy_up.go",
-        "directory.go",
-        "filesystem.go",
-        "fstree.go",
-        "overlay.go",
-        "regular_file.go",
-        "save_restore.go",
-    ],
-    visibility = ["//pkg/sentry:internal"],
-    deps = [
-        "//pkg/abi/linux",
-        "//pkg/context",
-        "//pkg/errors/linuxerr",
-        "//pkg/fspath",
-        "//pkg/hostarch",
-        "//pkg/log",
-        "//pkg/refs",
-        "//pkg/refsvfs2",
-        "//pkg/sentry/arch",
-        "//pkg/sentry/fs/lock",
-        "//pkg/sentry/kernel/auth",
-        "//pkg/sentry/memmap",
-        "//pkg/sentry/socket/unix/transport",
-        "//pkg/sentry/vfs",
-        "//pkg/sync",
-        "//pkg/syserror",
-        "//pkg/usermem",
-        "//pkg/waiter",
-    ],
-)
diff --git a/pkg/sentry/fsimpl/overlay/fstree.go b/pkg/sentry/fsimpl/overlay/fstree.go
new file mode 100644
index 000000000..c3eb062ed
--- /dev/null
+++ b/pkg/sentry/fsimpl/overlay/fstree.go
@@ -0,0 +1,55 @@
+package overlay
+
+import (
+	"gvisor.dev/gvisor/pkg/fspath"
+	"gvisor.dev/gvisor/pkg/sentry/vfs"
+)
+
+// IsAncestorDentry returns true if d is an ancestor of d2; that is, d is
+// either d2's parent or an ancestor of d2's parent.
+func genericIsAncestorDentry(d, d2 *dentry) bool {
+	for d2 != nil {
+		if d2.parent == d {
+			return true
+		}
+		if d2.parent == d2 {
+			return false
+		}
+		d2 = d2.parent
+	}
+	return false
+}
+
+// ParentOrSelf returns d.parent. If d.parent is nil, ParentOrSelf returns d.
+func genericParentOrSelf(d *dentry) *dentry {
+	if d.parent != nil {
+		return d.parent
+	}
+	return d
+}
+
+// PrependPath is a generic implementation of FilesystemImpl.PrependPath().
+func genericPrependPath(vfsroot vfs.VirtualDentry, mnt *vfs.Mount, d *dentry, b *fspath.Builder) error {
+	for {
+		if mnt == vfsroot.Mount() && &d.vfsd == vfsroot.Dentry() {
+			return vfs.PrependPathAtVFSRootError{}
+		}
+		if mnt != nil && &d.vfsd == mnt.Root() {
+			return nil
+		}
+		if d.parent == nil {
+			return vfs.PrependPathAtNonMountRootError{}
+		}
+		b.PrependComponent(d.name)
+		d = d.parent
+	}
+}
+
+// DebugPathname returns a pathname to d relative to its filesystem root.
+// DebugPathname does not correspond to any Linux function; it's used to
+// generate dentry pathnames for debugging.
+func genericDebugPathname(d *dentry) string {
+	var b fspath.Builder
+	_ = genericPrependPath(vfs.VirtualDentry{}, nil, d, &b)
+	return b.String()
+}
diff --git a/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go b/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go
new file mode 100644
index 000000000..923a2e71a
--- /dev/null
+++ b/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go
@@ -0,0 +1,321 @@
+// automatically generated by stateify.
+
+package overlay
+
+import (
+	"gvisor.dev/gvisor/pkg/state"
+)
+
+func (fd *directoryFD) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.directoryFD"
+}
+
+func (fd *directoryFD) StateFields() []string {
+	return []string{
+		"fileDescription",
+		"DirectoryFileDescriptionDefaultImpl",
+		"DentryMetadataFileDescriptionImpl",
+		"off",
+		"dirents",
+	}
+}
+
+func (fd *directoryFD) beforeSave() {}
+
+// +checklocksignore
+func (fd *directoryFD) StateSave(stateSinkObject state.Sink) {
+	fd.beforeSave()
+	stateSinkObject.Save(0, &fd.fileDescription)
+	stateSinkObject.Save(1, &fd.DirectoryFileDescriptionDefaultImpl)
+	stateSinkObject.Save(2, &fd.DentryMetadataFileDescriptionImpl)
+	stateSinkObject.Save(3, &fd.off)
+	stateSinkObject.Save(4, &fd.dirents)
+}
+
+func (fd *directoryFD) afterLoad() {}
+
+// +checklocksignore
+func (fd *directoryFD) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &fd.fileDescription)
+	stateSourceObject.Load(1, &fd.DirectoryFileDescriptionDefaultImpl)
+	stateSourceObject.Load(2, &fd.DentryMetadataFileDescriptionImpl)
+	stateSourceObject.Load(3, &fd.off)
+	stateSourceObject.Load(4, &fd.dirents)
+}
+
+func (fstype *FilesystemType) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.FilesystemType"
+}
+
+func (fstype *FilesystemType) StateFields() []string {
+	return []string{}
+}
+
+func (fstype *FilesystemType) beforeSave() {}
+
+// +checklocksignore
+func (fstype *FilesystemType) StateSave(stateSinkObject state.Sink) {
+	fstype.beforeSave()
+}
+
+func (fstype *FilesystemType) afterLoad() {}
+
+// +checklocksignore
+func (fstype *FilesystemType) StateLoad(stateSourceObject state.Source) {
+}
+
+func (f *FilesystemOptions) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.FilesystemOptions"
+}
+
+func (f *FilesystemOptions) StateFields() []string {
+	return []string{
+		"UpperRoot",
+		"LowerRoots",
+	}
+}
+
+func (f *FilesystemOptions) beforeSave() {}
+
+// +checklocksignore
+func (f *FilesystemOptions) StateSave(stateSinkObject state.Sink) {
+	f.beforeSave()
+	stateSinkObject.Save(0, &f.UpperRoot)
+	stateSinkObject.Save(1, &f.LowerRoots)
+}
+
+func (f *FilesystemOptions) afterLoad() {}
+
+// +checklocksignore
+func (f *FilesystemOptions) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &f.UpperRoot)
+	stateSourceObject.Load(1, &f.LowerRoots)
+}
+
+func (fs *filesystem) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.filesystem"
+}
+
+func (fs *filesystem) StateFields() []string {
+	return []string{
+		"vfsfs",
+		"opts",
+		"creds",
+		"privateDevMinors",
+	}
+}
+
+func (fs *filesystem) beforeSave() {}
+
+// +checklocksignore
+func (fs *filesystem) StateSave(stateSinkObject state.Sink) {
+	fs.beforeSave()
+	stateSinkObject.Save(0, &fs.vfsfs)
+	stateSinkObject.Save(1, &fs.opts)
+	stateSinkObject.Save(2, &fs.creds)
+	stateSinkObject.Save(3, &fs.privateDevMinors)
+}
+
+func (fs *filesystem) afterLoad() {}
+
+// +checklocksignore
+func (fs *filesystem) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &fs.vfsfs)
+	stateSourceObject.Load(1, &fs.opts)
+	stateSourceObject.Load(2, &fs.creds)
+	stateSourceObject.Load(3, &fs.privateDevMinors)
+}
+
+func (l *layerDevNumber) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.layerDevNumber"
+}
+
+func (l *layerDevNumber) StateFields() []string {
+	return []string{
+		"major",
+		"minor",
+	}
+}
+
+func (l *layerDevNumber) beforeSave() {}
+
+// +checklocksignore
+func (l *layerDevNumber) StateSave(stateSinkObject state.Sink) {
+	l.beforeSave()
+	stateSinkObject.Save(0, &l.major)
+	stateSinkObject.Save(1, &l.minor)
+}
+
+func (l *layerDevNumber) afterLoad() {}
+
+// +checklocksignore
+func (l *layerDevNumber) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &l.major)
+	stateSourceObject.Load(1, &l.minor)
+}
+
+func (d *dentry) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.dentry"
+}
+
+func (d *dentry) StateFields() []string {
+	return []string{
+		"vfsd",
+		"refs",
+		"fs",
+		"mode",
+		"uid",
+		"gid",
+		"copiedUp",
+		"parent",
+		"name",
+		"children",
+		"dirents",
+		"upperVD",
+		"lowerVDs",
+		"inlineLowerVDs",
+		"devMajor",
+		"devMinor",
+		"ino",
+		"lowerMappings",
+		"wrappedMappable",
+		"isMappable",
+		"locks",
+		"watches",
+	}
+}
+
+func (d *dentry) beforeSave() {}
+
+// +checklocksignore
+func (d *dentry) StateSave(stateSinkObject state.Sink) {
+	d.beforeSave()
+	stateSinkObject.Save(0, &d.vfsd)
+	stateSinkObject.Save(1, &d.refs)
+	stateSinkObject.Save(2, &d.fs)
+	stateSinkObject.Save(3, &d.mode)
+	stateSinkObject.Save(4, &d.uid)
+	stateSinkObject.Save(5, &d.gid)
+	stateSinkObject.Save(6, &d.copiedUp)
+	stateSinkObject.Save(7, &d.parent)
+	stateSinkObject.Save(8, &d.name)
+	stateSinkObject.Save(9, &d.children)
+	stateSinkObject.Save(10, &d.dirents)
+	stateSinkObject.Save(11, &d.upperVD)
+	stateSinkObject.Save(12, &d.lowerVDs)
+	stateSinkObject.Save(13, &d.inlineLowerVDs)
+	stateSinkObject.Save(14, &d.devMajor)
+	stateSinkObject.Save(15, &d.devMinor)
+	stateSinkObject.Save(16, &d.ino)
+	stateSinkObject.Save(17, &d.lowerMappings)
+	stateSinkObject.Save(18, &d.wrappedMappable)
+	stateSinkObject.Save(19, &d.isMappable)
+	stateSinkObject.Save(20, &d.locks)
+	stateSinkObject.Save(21, &d.watches)
+}
+
+// +checklocksignore
+func (d *dentry) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &d.vfsd)
+	stateSourceObject.Load(1, &d.refs)
+	stateSourceObject.Load(2, &d.fs)
+	stateSourceObject.Load(3, &d.mode)
+	stateSourceObject.Load(4, &d.uid)
+	stateSourceObject.Load(5, &d.gid)
+	stateSourceObject.Load(6, &d.copiedUp)
+	stateSourceObject.Load(7, &d.parent)
+	stateSourceObject.Load(8, &d.name)
+	stateSourceObject.Load(9, &d.children)
+	stateSourceObject.Load(10, &d.dirents)
+	stateSourceObject.Load(11, &d.upperVD)
+	stateSourceObject.Load(12, &d.lowerVDs)
+	stateSourceObject.Load(13, &d.inlineLowerVDs)
+	stateSourceObject.Load(14, &d.devMajor)
+	stateSourceObject.Load(15, &d.devMinor)
+	stateSourceObject.Load(16, &d.ino)
+	stateSourceObject.Load(17, &d.lowerMappings)
+	stateSourceObject.Load(18, &d.wrappedMappable)
+	stateSourceObject.Load(19, &d.isMappable)
+	stateSourceObject.Load(20, &d.locks)
+	stateSourceObject.Load(21, &d.watches)
+	stateSourceObject.AfterLoad(d.afterLoad)
+}
+
+func (fd *fileDescription) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.fileDescription"
+}
+
+func (fd *fileDescription) StateFields() []string {
+	return []string{
+		"vfsfd",
+		"FileDescriptionDefaultImpl",
+		"LockFD",
+	}
+}
+
+func (fd *fileDescription) beforeSave() {}
+
+// +checklocksignore
+func (fd *fileDescription) StateSave(stateSinkObject state.Sink) {
+	fd.beforeSave()
+	stateSinkObject.Save(0, &fd.vfsfd)
+	stateSinkObject.Save(1, &fd.FileDescriptionDefaultImpl)
+	stateSinkObject.Save(2, &fd.LockFD)
+}
+
+func (fd *fileDescription) afterLoad() {}
+
+// +checklocksignore
+func (fd *fileDescription) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &fd.vfsfd)
+	stateSourceObject.Load(1, &fd.FileDescriptionDefaultImpl)
+	stateSourceObject.Load(2, &fd.LockFD)
+}
+
+func (fd *regularFileFD) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.regularFileFD"
+}
+
+func (fd *regularFileFD) StateFields() []string {
+	return []string{
+		"fileDescription",
+		"copiedUp",
+		"cachedFD",
+		"cachedFlags",
+		"lowerWaiters",
+	}
+}
+
+func (fd *regularFileFD) beforeSave() {}
+
+// +checklocksignore
+func (fd *regularFileFD) StateSave(stateSinkObject state.Sink) {
+	fd.beforeSave()
+	stateSinkObject.Save(0, &fd.fileDescription)
+	stateSinkObject.Save(1, &fd.copiedUp)
+	stateSinkObject.Save(2, &fd.cachedFD)
+	stateSinkObject.Save(3, &fd.cachedFlags)
+	stateSinkObject.Save(4, &fd.lowerWaiters)
+}
+
+func (fd *regularFileFD) afterLoad() {}
+
+// +checklocksignore
+func (fd *regularFileFD) StateLoad(stateSourceObject state.Source) {
+	stateSourceObject.Load(0, &fd.fileDescription)
+	stateSourceObject.Load(1, &fd.copiedUp)
+	stateSourceObject.Load(2, &fd.cachedFD)
+	stateSourceObject.Load(3, &fd.cachedFlags)
+	stateSourceObject.Load(4, &fd.lowerWaiters)
+}
+
+func init() {
+	state.Register((*directoryFD)(nil))
+	state.Register((*FilesystemType)(nil))
+	state.Register((*FilesystemOptions)(nil))
+	state.Register((*filesystem)(nil))
+	state.Register((*layerDevNumber)(nil))
+	state.Register((*dentry)(nil))
+	state.Register((*fileDescription)(nil))
+	state.Register((*regularFileFD)(nil))
+}