3 files changed, 334 insertions, 41 deletions
diff --git a/pkg/sentry/fsimpl/overlay/BUILD b/pkg/sentry/fsimpl/overlay/BUILD
deleted file mode 100644
index 8cf5b35d3..000000000
--- a/pkg/sentry/fsimpl/overlay/BUILD
+++ /dev/null
@@ -1,41 +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",
-        "non_directory.go",
-        "overlay.go",
-    ],
-    visibility = ["//pkg/sentry:internal"],
-    deps = [
-        "//pkg/abi/linux",
-        "//pkg/context",
-        "//pkg/fspath",
-        "//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",
-    ],
-)
diff --git a/pkg/sentry/fsimpl/overlay/fstree.go b/pkg/sentry/fsimpl/overlay/fstree.go
new file mode 100644
index 000000000..1fa1b4ad3
--- /dev/null
+++ b/pkg/sentry/fsimpl/overlay/fstree.go
@@ -0,0 +1,46 @@
+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 &d.vfsd == mnt.Root() {
+			return nil
+		}
+		if d.parent == nil {
+			return vfs.PrependPathAtNonMountRootError{}
+		}
+		b.PrependComponent(d.name)
+		d = d.parent
+	}
+}
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..d3e649672
--- /dev/null
+++ b/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go
@@ -0,0 +1,288 @@
+// automatically generated by stateify.
+
+package overlay
+
+import (
+	"gvisor.dev/gvisor/pkg/state"
+)
+
+func (x *directoryFD) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.directoryFD"
+}
+
+func (x *directoryFD) StateFields() []string {
+	return []string{
+		"fileDescription",
+		"DirectoryFileDescriptionDefaultImpl",
+		"DentryMetadataFileDescriptionImpl",
+		"off",
+		"dirents",
+	}
+}
+
+func (x *directoryFD) beforeSave() {}
+
+func (x *directoryFD) StateSave(m state.Sink) {
+	x.beforeSave()
+	m.Save(0, &x.fileDescription)
+	m.Save(1, &x.DirectoryFileDescriptionDefaultImpl)
+	m.Save(2, &x.DentryMetadataFileDescriptionImpl)
+	m.Save(3, &x.off)
+	m.Save(4, &x.dirents)
+}
+
+func (x *directoryFD) afterLoad() {}
+
+func (x *directoryFD) StateLoad(m state.Source) {
+	m.Load(0, &x.fileDescription)
+	m.Load(1, &x.DirectoryFileDescriptionDefaultImpl)
+	m.Load(2, &x.DentryMetadataFileDescriptionImpl)
+	m.Load(3, &x.off)
+	m.Load(4, &x.dirents)
+}
+
+func (x *nonDirectoryFD) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.nonDirectoryFD"
+}
+
+func (x *nonDirectoryFD) StateFields() []string {
+	return []string{
+		"fileDescription",
+		"copiedUp",
+		"cachedFD",
+		"cachedFlags",
+	}
+}
+
+func (x *nonDirectoryFD) beforeSave() {}
+
+func (x *nonDirectoryFD) StateSave(m state.Sink) {
+	x.beforeSave()
+	m.Save(0, &x.fileDescription)
+	m.Save(1, &x.copiedUp)
+	m.Save(2, &x.cachedFD)
+	m.Save(3, &x.cachedFlags)
+}
+
+func (x *nonDirectoryFD) afterLoad() {}
+
+func (x *nonDirectoryFD) StateLoad(m state.Source) {
+	m.Load(0, &x.fileDescription)
+	m.Load(1, &x.copiedUp)
+	m.Load(2, &x.cachedFD)
+	m.Load(3, &x.cachedFlags)
+}
+
+func (x *FilesystemType) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.FilesystemType"
+}
+
+func (x *FilesystemType) StateFields() []string {
+	return []string{}
+}
+
+func (x *FilesystemType) beforeSave() {}
+
+func (x *FilesystemType) StateSave(m state.Sink) {
+	x.beforeSave()
+}
+
+func (x *FilesystemType) afterLoad() {}
+
+func (x *FilesystemType) StateLoad(m state.Source) {
+}
+
+func (x *FilesystemOptions) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.FilesystemOptions"
+}
+
+func (x *FilesystemOptions) StateFields() []string {
+	return []string{
+		"UpperRoot",
+		"LowerRoots",
+	}
+}
+
+func (x *FilesystemOptions) beforeSave() {}
+
+func (x *FilesystemOptions) StateSave(m state.Sink) {
+	x.beforeSave()
+	m.Save(0, &x.UpperRoot)
+	m.Save(1, &x.LowerRoots)
+}
+
+func (x *FilesystemOptions) afterLoad() {}
+
+func (x *FilesystemOptions) StateLoad(m state.Source) {
+	m.Load(0, &x.UpperRoot)
+	m.Load(1, &x.LowerRoots)
+}
+
+func (x *filesystem) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.filesystem"
+}
+
+func (x *filesystem) StateFields() []string {
+	return []string{
+		"vfsfs",
+		"opts",
+		"creds",
+		"dirDevMinor",
+		"lowerDevMinors",
+		"lastDirIno",
+	}
+}
+
+func (x *filesystem) beforeSave() {}
+
+func (x *filesystem) StateSave(m state.Sink) {
+	x.beforeSave()
+	m.Save(0, &x.vfsfs)
+	m.Save(1, &x.opts)
+	m.Save(2, &x.creds)
+	m.Save(3, &x.dirDevMinor)
+	m.Save(4, &x.lowerDevMinors)
+	m.Save(5, &x.lastDirIno)
+}
+
+func (x *filesystem) afterLoad() {}
+
+func (x *filesystem) StateLoad(m state.Source) {
+	m.Load(0, &x.vfsfs)
+	m.Load(1, &x.opts)
+	m.Load(2, &x.creds)
+	m.Load(3, &x.dirDevMinor)
+	m.Load(4, &x.lowerDevMinors)
+	m.Load(5, &x.lastDirIno)
+}
+
+func (x *dentry) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.dentry"
+}
+
+func (x *dentry) StateFields() []string {
+	return []string{
+		"vfsd",
+		"refs",
+		"fs",
+		"mode",
+		"uid",
+		"gid",
+		"copiedUp",
+		"parent",
+		"name",
+		"children",
+		"dirents",
+		"upperVD",
+		"lowerVDs",
+		"inlineLowerVDs",
+		"devMajor",
+		"devMinor",
+		"ino",
+		"mapsMu",
+		"lowerMappings",
+		"dataMu",
+		"wrappedMappable",
+		"isMappable",
+		"locks",
+		"watches",
+	}
+}
+
+func (x *dentry) beforeSave() {}
+
+func (x *dentry) StateSave(m state.Sink) {
+	x.beforeSave()
+	m.Save(0, &x.vfsd)
+	m.Save(1, &x.refs)
+	m.Save(2, &x.fs)
+	m.Save(3, &x.mode)
+	m.Save(4, &x.uid)
+	m.Save(5, &x.gid)
+	m.Save(6, &x.copiedUp)
+	m.Save(7, &x.parent)
+	m.Save(8, &x.name)
+	m.Save(9, &x.children)
+	m.Save(10, &x.dirents)
+	m.Save(11, &x.upperVD)
+	m.Save(12, &x.lowerVDs)
+	m.Save(13, &x.inlineLowerVDs)
+	m.Save(14, &x.devMajor)
+	m.Save(15, &x.devMinor)
+	m.Save(16, &x.ino)
+	m.Save(17, &x.mapsMu)
+	m.Save(18, &x.lowerMappings)
+	m.Save(19, &x.dataMu)
+	m.Save(20, &x.wrappedMappable)
+	m.Save(21, &x.isMappable)
+	m.Save(22, &x.locks)
+	m.Save(23, &x.watches)
+}
+
+func (x *dentry) afterLoad() {}
+
+func (x *dentry) StateLoad(m state.Source) {
+	m.Load(0, &x.vfsd)
+	m.Load(1, &x.refs)
+	m.Load(2, &x.fs)
+	m.Load(3, &x.mode)
+	m.Load(4, &x.uid)
+	m.Load(5, &x.gid)
+	m.Load(6, &x.copiedUp)
+	m.Load(7, &x.parent)
+	m.Load(8, &x.name)
+	m.Load(9, &x.children)
+	m.Load(10, &x.dirents)
+	m.Load(11, &x.upperVD)
+	m.Load(12, &x.lowerVDs)
+	m.Load(13, &x.inlineLowerVDs)
+	m.Load(14, &x.devMajor)
+	m.Load(15, &x.devMinor)
+	m.Load(16, &x.ino)
+	m.Load(17, &x.mapsMu)
+	m.Load(18, &x.lowerMappings)
+	m.Load(19, &x.dataMu)
+	m.Load(20, &x.wrappedMappable)
+	m.Load(21, &x.isMappable)
+	m.Load(22, &x.locks)
+	m.Load(23, &x.watches)
+}
+
+func (x *fileDescription) StateTypeName() string {
+	return "pkg/sentry/fsimpl/overlay.fileDescription"
+}
+
+func (x *fileDescription) StateFields() []string {
+	return []string{
+		"vfsfd",
+		"FileDescriptionDefaultImpl",
+		"LockFD",
+	}
+}
+
+func (x *fileDescription) beforeSave() {}
+
+func (x *fileDescription) StateSave(m state.Sink) {
+	x.beforeSave()
+	m.Save(0, &x.vfsfd)
+	m.Save(1, &x.FileDescriptionDefaultImpl)
+	m.Save(2, &x.LockFD)
+}
+
+func (x *fileDescription) afterLoad() {}
+
+func (x *fileDescription) StateLoad(m state.Source) {
+	m.Load(0, &x.vfsfd)
+	m.Load(1, &x.FileDescriptionDefaultImpl)
+	m.Load(2, &x.LockFD)
+}
+
+func init() {
+	state.Register((*directoryFD)(nil))
+	state.Register((*nonDirectoryFD)(nil))
+	state.Register((*FilesystemType)(nil))
+	state.Register((*FilesystemOptions)(nil))
+	state.Register((*filesystem)(nil))
+	state.Register((*dentry)(nil))
+	state.Register((*fileDescription)(nil))
+}