From f804e05360c00ae09ca9852415d54c4ff314099c Mon Sep 17 00:00:00 2001
From: gammazero <11790789+gammazero@users.noreply.github.com>
Date: Mon, 12 Aug 2024 19:55:40 -0700
Subject: [PATCH 1/5] feat: Support UnixFS mode and modification times in ipld
 dag and mfs

Adds support for storing and retrieving file mode and last modification time.

Support added to:

Support added to:
- Files
- LinkFiles
- Webfiles
- Directories

Tar archives are supported by the parent branch.
---
 ipld/unixfs/file/unixfile.go                  |  47 ++--
 .../unixfs/importer/balanced/balanced_test.go |  48 ++++
 ipld/unixfs/importer/balanced/builder.go      |  29 +-
 ipld/unixfs/importer/helpers/dagbuilder.go    |  97 +++++--
 ipld/unixfs/importer/trickle/trickle_test.go  | 109 +++++++-
 ipld/unixfs/importer/trickle/trickledag.go    |  22 +-
 ipld/unixfs/io/dagreader.go                   |  25 +-
 ipld/unixfs/mod/dagmodifier.go                |  17 +-
 ipld/unixfs/pb/unixfs.pb.go                   | 112 ++++++--
 ipld/unixfs/pb/unixfs.proto                   |  17 ++
 ipld/unixfs/unixfs.go                         | 141 +++++++++-
 ipld/unixfs/unixfs_test.go                    | 250 ++++++++++++++++++
 mfs/dir.go                                    |  77 +++++-
 mfs/file.go                                   |  90 +++++++
 mfs/mfs_test.go                               | 155 ++++++++++-
 mfs/ops.go                                    |  23 +-
 mfs/root.go                                   |   3 +
 17 files changed, 1168 insertions(+), 94 deletions(-)

diff --git a/ipld/unixfs/file/unixfile.go b/ipld/unixfs/file/unixfile.go
index 0a923e937..0cf7616c1 100644
--- a/ipld/unixfs/file/unixfile.go
+++ b/ipld/unixfs/file/unixfile.go
@@ -23,7 +23,8 @@ type ufsDirectory struct {
 	dserv ipld.DAGService
 	dir   uio.Directory
 	size  int64
-	stat  os.FileInfo
+	mode  os.FileMode
+	mtime time.Time
 }
 
 type ufsIterator struct {
@@ -122,17 +123,11 @@ func (d *ufsDirectory) Entries() files.DirIterator {
 }
 
 func (d *ufsDirectory) Mode() os.FileMode {
-	if d.stat == nil {
-		return 0
-	}
-	return d.stat.Mode()
+	return d.mode
 }
 
 func (d *ufsDirectory) ModTime() time.Time {
-	if d.stat == nil {
-		return time.Time{}
-	}
-	return d.stat.ModTime()
+	return d.mtime
 }
 
 func (d *ufsDirectory) Size() (int64, error) {
@@ -141,28 +136,21 @@ func (d *ufsDirectory) Size() (int64, error) {
 
 type ufsFile struct {
 	uio.DagReader
-	stat os.FileInfo
 }
 
 func (f *ufsFile) Mode() os.FileMode {
-	if f.stat == nil {
-		return 0
-	}
-	return f.stat.Mode()
+	return f.DagReader.Mode()
 }
 
 func (f *ufsFile) ModTime() time.Time {
-	if f.stat == nil {
-		return time.Time{}
-	}
-	return f.stat.ModTime()
+	return f.DagReader.ModTime()
 }
 
 func (f *ufsFile) Size() (int64, error) {
 	return int64(f.DagReader.Size()), nil
 }
 
-func newUnixfsDir(ctx context.Context, dserv ipld.DAGService, nd *dag.ProtoNode, stat os.FileInfo) (files.Directory, error) {
+func newUnixfsDir(ctx context.Context, dserv ipld.DAGService, nd *dag.ProtoNode) (files.Directory, error) {
 	dir, err := uio.NewDirectoryFromNode(dserv, nd)
 	if err != nil {
 		return nil, err
@@ -173,32 +161,35 @@ func newUnixfsDir(ctx context.Context, dserv ipld.DAGService, nd *dag.ProtoNode,
 		return nil, err
 	}
 
+	fsn, err := ft.FSNodeFromBytes(nd.Data())
+	if err != nil {
+		return nil, err
+	}
+
 	return &ufsDirectory{
 		ctx:   ctx,
 		dserv: dserv,
 
-		dir:  dir,
-		size: int64(size),
-		stat: stat,
+		dir:   dir,
+		size:  int64(size),
+		mode:  fsn.Mode(),
+		mtime: fsn.ModTime(),
 	}, nil
 }
 
 func NewUnixfsFile(ctx context.Context, dserv ipld.DAGService, nd ipld.Node) (files.Node, error) {
-	return NewUnixfsFileWithStat(ctx, dserv, nd, nil)
-}
-
-func NewUnixfsFileWithStat(ctx context.Context, dserv ipld.DAGService, nd ipld.Node, stat os.FileInfo) (files.Node, error) {
 	switch dn := nd.(type) {
 	case *dag.ProtoNode:
 		fsn, err := ft.FSNodeFromBytes(dn.Data())
 		if err != nil {
 			return nil, err
 		}
+
 		if fsn.IsDir() {
-			return newUnixfsDir(ctx, dserv, dn, stat)
+			return newUnixfsDir(ctx, dserv, dn)
 		}
 		if fsn.Type() == ft.TSymlink {
-			return files.NewLinkFile(string(fsn.Data()), stat), nil
+			return files.NewSymlinkFile(string(fsn.Data()), fsn.ModTime()), nil
 		}
 
 	case *dag.RawNode:
diff --git a/ipld/unixfs/importer/balanced/balanced_test.go b/ipld/unixfs/importer/balanced/balanced_test.go
index 5a5dcf9ad..4ea4cb8a9 100644
--- a/ipld/unixfs/importer/balanced/balanced_test.go
+++ b/ipld/unixfs/importer/balanced/balanced_test.go
@@ -7,6 +7,7 @@ import (
 	"io"
 	mrand "math/rand"
 	"testing"
+	"time"
 
 	h "github.com/ipfs/boxo/ipld/unixfs/importer/helpers"
 	uio "github.com/ipfs/boxo/ipld/unixfs/io"
@@ -26,6 +27,10 @@ func buildTestDag(ds ipld.DAGService, spl chunker.Splitter) (*dag.ProtoNode, err
 		Maxlinks: h.DefaultLinksPerBlock,
 	}
 
+	return buildTestDagWithParams(spl, dbp)
+}
+
+func buildTestDagWithParams(spl chunker.Splitter, dbp h.DagBuilderParams) (*dag.ProtoNode, error) {
 	db, err := dbp.New(spl)
 	if err != nil {
 		return nil, err
@@ -335,3 +340,46 @@ func TestSeekingConsistency(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestMetadataNoData(t *testing.T) {
+	testMetadata(t, new(bytes.Buffer))
+}
+
+func TestMetadata(t *testing.T) {
+	nbytes := 3 * chunker.DefaultBlockSize
+	buf := new(bytes.Buffer)
+	_, err := io.CopyN(buf, random.NewRand(), nbytes)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	testMetadata(t, buf)
+}
+
+func testMetadata(t *testing.T, buf *bytes.Buffer) {
+	dagserv := mdtest.Mock()
+	dbp := h.DagBuilderParams{
+		Dagserv:     dagserv,
+		Maxlinks:    h.DefaultLinksPerBlock,
+		FileMode:    0522,
+		FileModTime: time.Unix(1638111600, 76552),
+	}
+
+	nd, err := buildTestDagWithParams(chunker.DefaultSplitter(buf), dbp)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	dr, err := uio.NewDagReader(context.Background(), nd, dagserv)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !dr.ModTime().Equal(dbp.FileModTime) {
+		t.Errorf("got modtime %v, wanted %v", dr.ModTime(), dbp.FileModTime)
+	}
+
+	if dr.Mode() != dbp.FileMode {
+		t.Errorf("got filemode %o, wanted %o", dr.Mode(), dbp.FileMode)
+	}
+}
diff --git a/ipld/unixfs/importer/balanced/builder.go b/ipld/unixfs/importer/balanced/builder.go
index 0fdb0fd28..915d0a439 100644
--- a/ipld/unixfs/importer/balanced/builder.go
+++ b/ipld/unixfs/importer/balanced/builder.go
@@ -130,18 +130,33 @@ import (
 //	  | Chunk 1 |   | Chunk 2 |   | Chunk 3 |
 //	  +=========+   +=========+   + - - - - +
 func Layout(db *h.DagBuilderHelper) (ipld.Node, error) {
+	var root ipld.Node
+	var err error
+
 	if db.Done() {
-		// No data, return just an empty node.
-		root, err := db.NewLeafNode(nil, ft.TFile)
-		if err != nil {
-			return nil, err
-		}
+		// No data, just create an empty node.
+		root, err = db.NewLeafNode(nil, ft.TFile)
 		// This works without Filestore support (`ProcessFileStore`).
 		// TODO: Why? Is there a test case missing?
+	} else {
+		root, err = layoutData(db)
+	}
+
+	if err != nil {
+		return nil, err
+	}
 
-		return root, db.Add(root)
+	if db.HasFileAttributes() {
+		err = db.SetFileAttributes(root)
+		if err != nil {
+			return nil, err
+		}
 	}
 
+	return root, db.Add(root)
+}
+
+func layoutData(db *h.DagBuilderHelper) (ipld.Node, error) {
 	// The first `root` will be a single leaf node with data
 	// (corner case), after that subsequent `root` nodes will
 	// always be internal nodes (with a depth > 0) that can
@@ -172,7 +187,7 @@ func Layout(db *h.DagBuilderHelper) (ipld.Node, error) {
 		}
 	}
 
-	return root, db.Add(root)
+	return root, nil
 }
 
 // fillNodeRec will "fill" the given internal (non-leaf) `node` with data by
diff --git a/ipld/unixfs/importer/helpers/dagbuilder.go b/ipld/unixfs/importer/helpers/dagbuilder.go
index 25514d795..aefffad15 100644
--- a/ipld/unixfs/importer/helpers/dagbuilder.go
+++ b/ipld/unixfs/importer/helpers/dagbuilder.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"io"
 	"os"
+	"time"
 
 	dag "github.com/ipfs/boxo/ipld/merkledag"
 
@@ -23,13 +24,15 @@ var ErrMissingFsRef = errors.New("missing file path or URL, can't create filesto
 // DagBuilderHelper wraps together a bunch of objects needed to
 // efficiently create unixfs dag trees
 type DagBuilderHelper struct {
-	dserv      ipld.DAGService
-	spl        chunker.Splitter
-	recvdErr   error
-	rawLeaves  bool
-	nextData   []byte // the next item to return.
-	maxlinks   int
-	cidBuilder cid.Builder
+	dserv       ipld.DAGService
+	spl         chunker.Splitter
+	recvdErr    error
+	rawLeaves   bool
+	nextData    []byte // the next item to return.
+	maxlinks    int
+	cidBuilder  cid.Builder
+	fileMode    os.FileMode
+	fileModTime time.Time
 
 	// Filestore support variables.
 	// ----------------------------
@@ -62,6 +65,12 @@ type DagBuilderParams struct {
 	// DAGService to write blocks to (required)
 	Dagserv ipld.DAGService
 
+	// The unixfs file mode
+	FileMode os.FileMode
+
+	// The unixfs last modified time
+	FileModTime time.Time
+
 	// NoCopy signals to the chunker that it should track fileinfo for
 	// filestore adds
 	NoCopy bool
@@ -71,11 +80,13 @@ type DagBuilderParams struct {
 // chunker.Splitter as data source.
 func (dbp *DagBuilderParams) New(spl chunker.Splitter) (*DagBuilderHelper, error) {
 	db := &DagBuilderHelper{
-		dserv:      dbp.Dagserv,
-		spl:        spl,
-		rawLeaves:  dbp.RawLeaves,
-		cidBuilder: dbp.CidBuilder,
-		maxlinks:   dbp.Maxlinks,
+		dserv:       dbp.Dagserv,
+		spl:         spl,
+		rawLeaves:   dbp.RawLeaves,
+		cidBuilder:  dbp.CidBuilder,
+		maxlinks:    dbp.Maxlinks,
+		fileMode:    dbp.FileMode,
+		fileModTime: dbp.FileModTime,
 	}
 	if fi, ok := spl.Reader().(files.FileInfo); dbp.NoCopy && ok {
 		db.fullPath = fi.AbsPath()
@@ -138,9 +149,9 @@ func (db *DagBuilderHelper) GetCidBuilder() cid.Builder {
 	return db.cidBuilder
 }
 
-// NewLeafNode creates a leaf node filled with data.  If rawLeaves is
-// defined then a raw leaf will be returned.  Otherwise, it will create
-// and return `FSNodeOverDag` with `fsNodeType`.
+// NewLeafNode creates a leaf node filled with data. If rawLeaves is defined
+// then a raw leaf will be returned. Otherwise, it will create and return
+// `FSNodeOverDag` with `fsNodeType`.
 func (db *DagBuilderHelper) NewLeafNode(data []byte, fsNodeType pb.Data_DataType) (ipld.Node, error) {
 	if len(data) > BlockSizeLimit {
 		return nil, ErrSizeLimitExceeded
@@ -161,6 +172,7 @@ func (db *DagBuilderHelper) NewLeafNode(data []byte, fsNodeType pb.Data_DataType
 	// Encapsulate the data in UnixFS node (instead of a raw node).
 	fsNodeOverDag := db.NewFSNodeOverDag(fsNodeType)
 	fsNodeOverDag.SetFileData(data)
+
 	node, err := fsNodeOverDag.Commit()
 	if err != nil {
 		return nil, err
@@ -172,9 +184,10 @@ func (db *DagBuilderHelper) NewLeafNode(data []byte, fsNodeType pb.Data_DataType
 	return node, nil
 }
 
-// FillNodeLayer will add datanodes as children to the give node until
+// FillNodeLayer will add data-nodes as children to the given node until
 // it is full in this layer or no more data.
-// NOTE: This function creates raw data nodes so it only works
+//
+// NOTE: This function creates raw data nodes, so it only works
 // for the `trickle.Layout`.
 func (db *DagBuilderHelper) FillNodeLayer(node *FSNodeOverDag) error {
 	// while we have room AND we're not done
@@ -265,6 +278,34 @@ func (db *DagBuilderHelper) Maxlinks() int {
 	return db.maxlinks
 }
 
+// HasFileAttributes will return false if Filestore is being used,
+// otherwise returns true if a file mode or last modification time is set.
+func (db *DagBuilderHelper) HasFileAttributes() bool {
+	return db.fullPath == "" && (db.fileMode != 0 || !db.fileModTime.IsZero())
+}
+
+// SetFileAttributes stores file attributes present in the `DagBuilderHelper`
+// into the associated `ft.FSNode`.
+func (db *DagBuilderHelper) SetFileAttributes(n ipld.Node) error {
+	if pn, ok := n.(*dag.ProtoNode); ok {
+		fsn, err := ft.FSNodeFromBytes(pn.Data())
+		if err != nil {
+			return err
+		}
+		fsn.SetModTime(db.fileModTime)
+		fsn.SetMode(db.fileMode)
+
+		d, err := fsn.GetBytes()
+		if err != nil {
+			return err
+		}
+
+		pn.SetData(d)
+	}
+
+	return nil
+}
+
 // FSNodeOverDag encapsulates an `unixfs.FSNode` that will be stored in a
 // `dag.ProtoNode`. Instead of just having a single `ipld.Node` that
 // would need to be constantly (un)packed to access and modify its
@@ -288,7 +329,7 @@ type FSNodeOverDag struct {
 }
 
 // NewFSNodeOverDag creates a new `dag.ProtoNode` and `ft.FSNode`
-// decoupled from one onther (and will continue in that way until
+// decoupled from one anonther (and will continue in that way until
 // `Commit` is called), with `fsNodeType` specifying the type of
 // the UnixFS layer node (either `File` or `Raw`).
 func (db *DagBuilderHelper) NewFSNodeOverDag(fsNodeType pb.Data_DataType) *FSNodeOverDag {
@@ -374,6 +415,26 @@ func (n *FSNodeOverDag) SetFileData(fileData []byte) {
 	n.file.SetData(fileData)
 }
 
+// SetMode sets the file mode of the associated `ft.FSNode`.
+func (n *FSNodeOverDag) SetMode(mode os.FileMode) {
+	n.file.SetMode(mode)
+}
+
+// SetModTime sets the file modification time of the associated `ft.FSNode`.
+func (n *FSNodeOverDag) SetModTime(ts time.Time) {
+	n.file.SetModTime(ts)
+}
+
+// Mode returns the file mode of the associated `ft.FSNode`
+func (n *FSNodeOverDag) Mode() os.FileMode {
+	return n.file.Mode()
+}
+
+// ModTime returns the last modification time of the associated `ft.FSNode`
+func (n *FSNodeOverDag) ModTime() time.Time {
+	return n.file.ModTime()
+}
+
 // GetDagNode fills out the proper formatting for the FSNodeOverDag node
 // inside of a DAG node and returns the dag node.
 // TODO: Check if we have committed (passed the UnixFS information
diff --git a/ipld/unixfs/importer/trickle/trickle_test.go b/ipld/unixfs/importer/trickle/trickle_test.go
index 9078fdc02..61899c9ff 100644
--- a/ipld/unixfs/importer/trickle/trickle_test.go
+++ b/ipld/unixfs/importer/trickle/trickle_test.go
@@ -7,6 +7,7 @@ import (
 	"io"
 	mrand "math/rand"
 	"testing"
+	"time"
 
 	ft "github.com/ipfs/boxo/ipld/unixfs"
 	h "github.com/ipfs/boxo/ipld/unixfs/importer/helpers"
@@ -40,6 +41,10 @@ func buildTestDag(ds ipld.DAGService, spl chunker.Splitter, rawLeaves UseRawLeav
 		RawLeaves: bool(rawLeaves),
 	}
 
+	return buildTestDagWithParams(ds, spl, dbp)
+}
+
+func buildTestDagWithParams(ds ipld.DAGService, spl chunker.Splitter, dbp h.DagBuilderParams) (*merkledag.ProtoNode, error) {
 	db, err := dbp.New(spl)
 	if err != nil {
 		return nil, err
@@ -59,7 +64,7 @@ func buildTestDag(ds ipld.DAGService, spl chunker.Splitter, rawLeaves UseRawLeav
 		Getter:      ds,
 		Direct:      dbp.Maxlinks,
 		LayerRepeat: depthRepeat,
-		RawLeaves:   bool(rawLeaves),
+		RawLeaves:   dbp.RawLeaves,
 	})
 }
 
@@ -668,3 +673,105 @@ func TestAppendSingleBytesToEmpty(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestAppendWithModTime(t *testing.T) {
+	const nbytes = 128 * 1024
+
+	timestamp := time.Now()
+	ds := mdtest.Mock()
+	buf := random.Bytes(nbytes)
+
+	nd := new(merkledag.ProtoNode)
+	nd.SetData(ft.FilePBDataWithStat(buf[:nbytes/2], nbytes/2, 0, timestamp))
+
+	dbp := &h.DagBuilderParams{
+		Dagserv:  ds,
+		Maxlinks: h.DefaultLinksPerBlock,
+	}
+
+	r := bytes.NewReader(buf[nbytes/2:])
+	db, err := dbp.New(chunker.NewSizeSplitter(r, 500))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	nd2, err := Append(context.Background(), nd, db)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fsn, _ := ft.ExtractFSNode(nd2)
+
+	if !fsn.ModTime().After(timestamp) {
+		t.Errorf("expected modification time to be updated")
+	}
+
+}
+
+func TestAppendToEmptyWithModTime(t *testing.T) {
+	timestamp := time.Now()
+	ds := mdtest.Mock()
+	nd := new(merkledag.ProtoNode)
+	nd.SetData(ft.FilePBDataWithStat(nil, 0, 0, timestamp))
+
+	dbp := &h.DagBuilderParams{
+		Dagserv:  ds,
+		Maxlinks: h.DefaultLinksPerBlock,
+	}
+
+	db, err := dbp.New(chunker.DefaultSplitter(bytes.NewReader([]byte("test"))))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	nd2, err := Append(context.Background(), nd, db)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fsn, _ := ft.ExtractFSNode(nd2)
+
+	if !fsn.ModTime().After(timestamp) {
+		t.Errorf("expected modification time to be updated")
+	}
+}
+
+func TestMetadata(t *testing.T) {
+	runBothSubtests(t, testMetadata)
+}
+
+func testMetadata(t *testing.T, rawLeaves UseRawLeaves) {
+	const nbytes = 3 * chunker.DefaultBlockSize
+	buf := new(bytes.Buffer)
+	_, err := io.CopyN(buf, random.NewRand(), nbytes)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	dagserv := mdtest.Mock()
+	dbp := h.DagBuilderParams{
+		Dagserv:     dagserv,
+		Maxlinks:    h.DefaultLinksPerBlock,
+		RawLeaves:   bool(rawLeaves),
+		FileMode:    0522,
+		FileModTime: time.Unix(1638111600, 76552),
+	}
+
+	nd, err := buildTestDagWithParams(dagserv, chunker.DefaultSplitter(buf), dbp)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	dr, err := uio.NewDagReader(context.Background(), nd, dagserv)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !dr.ModTime().Equal(dbp.FileModTime) {
+		t.Errorf("got modtime %v, wanted %v", dr.ModTime(), dbp.FileModTime)
+	}
+
+	if dr.Mode() != dbp.FileMode {
+		t.Errorf("got filemode %o, wanted %o", dr.Mode(), dbp.FileMode)
+	}
+}
diff --git a/ipld/unixfs/importer/trickle/trickledag.go b/ipld/unixfs/importer/trickle/trickledag.go
index 09a8b8672..2b9d31dfa 100644
--- a/ipld/unixfs/importer/trickle/trickledag.go
+++ b/ipld/unixfs/importer/trickle/trickledag.go
@@ -19,6 +19,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"time"
 
 	ft "github.com/ipfs/boxo/ipld/unixfs"
 	h "github.com/ipfs/boxo/ipld/unixfs/importer/helpers"
@@ -43,6 +44,13 @@ func Layout(db *h.DagBuilderHelper) (ipld.Node, error) {
 		return nil, err
 	}
 
+	if db.HasFileAttributes() {
+		err = db.SetFileAttributes(root)
+	}
+
+	if err != nil {
+		return nil, err
+	}
 	return root, db.Add(root)
 }
 
@@ -94,7 +102,6 @@ func Append(ctx context.Context, basen ipld.Node, db *h.DagBuilderHelper) (out i
 	}
 
 	// Convert to unixfs node for working with easily
-
 	fsn, err := h.NewFSNFromDag(base)
 	if err != nil {
 		return nil, err
@@ -109,9 +116,10 @@ func Append(ctx context.Context, basen ipld.Node, db *h.DagBuilderHelper) (out i
 		}
 
 		if db.Done() {
-			// TODO: If `FillNodeLayer` stop `Commit`ing this should be
-			// the place (besides the function end) to call it.
-			return fsn.GetDagNode()
+			if !fsn.ModTime().IsZero() {
+				fsn.SetModTime(time.Now())
+			}
+			return fsn.Commit()
 		}
 
 		// If continuing, our depth has increased by one
@@ -142,11 +150,7 @@ func Append(ctx context.Context, basen ipld.Node, db *h.DagBuilderHelper) (out i
 			}
 		}
 	}
-	_, err = fsn.Commit()
-	if err != nil {
-		return nil, err
-	}
-	return fsn.GetDagNode()
+	return fsn.Commit()
 }
 
 func appendFillLastChild(ctx context.Context, fsn *h.FSNodeOverDag, depth int, repeatNumber int, db *h.DagBuilderHelper) error {
diff --git a/ipld/unixfs/io/dagreader.go b/ipld/unixfs/io/dagreader.go
index 77dc8d921..bb1c83800 100644
--- a/ipld/unixfs/io/dagreader.go
+++ b/ipld/unixfs/io/dagreader.go
@@ -5,6 +5,8 @@ import (
 	"context"
 	"errors"
 	"io"
+	"os"
+	"time"
 
 	mdag "github.com/ipfs/boxo/ipld/merkledag"
 	unixfs "github.com/ipfs/boxo/ipld/unixfs"
@@ -29,6 +31,8 @@ var (
 type DagReader interface {
 	ReadSeekCloser
 	Size() uint64
+	Mode() os.FileMode
+	ModTime() time.Time
 	CtxReadFull(context.Context, []byte) (int, error)
 }
 
@@ -44,6 +48,8 @@ type ReadSeekCloser interface {
 // the given node, using the passed in DAGService for data retrieval.
 func NewDagReader(ctx context.Context, n ipld.Node, serv ipld.NodeGetter) (DagReader, error) {
 	var size uint64
+	var mode os.FileMode
+	var modTime time.Time
 
 	switch n := n.(type) {
 	case *mdag.RawNode:
@@ -55,6 +61,9 @@ func NewDagReader(ctx context.Context, n ipld.Node, serv ipld.NodeGetter) (DagRe
 			return nil, err
 		}
 
+		mode = fsNode.Mode()
+		modTime = fsNode.ModTime()
+
 		switch fsNode.Type() {
 		case unixfs.TFile, unixfs.TRaw:
 			size = fsNode.FileSize()
@@ -93,6 +102,8 @@ func NewDagReader(ctx context.Context, n ipld.Node, serv ipld.NodeGetter) (DagRe
 		cancel:    cancel,
 		serv:      serv,
 		size:      size,
+		mode:      mode,
+		modTime:   modTime,
 		rootNode:  n,
 		dagWalker: ipld.NewWalker(ctxWithCancel, ipld.NewNavigableIPLDNode(n, serv)),
 	}, nil
@@ -129,7 +140,19 @@ type dagReader struct {
 
 	// Passed to the `dagWalker` that will use it to request nodes.
 	// TODO: Revisit name.
-	serv ipld.NodeGetter
+	serv    ipld.NodeGetter
+	mode    os.FileMode
+	modTime time.Time
+}
+
+// Mode returns the UnixFS file mode or 0 if not set.
+func (dr *dagReader) Mode() os.FileMode {
+	return dr.mode
+}
+
+// ModTime returns the UnixFS file last modification time if set.
+func (dr *dagReader) ModTime() time.Time {
+	return dr.modTime
 }
 
 // Size returns the total size of the data from the DAG structured file.
diff --git a/ipld/unixfs/mod/dagmodifier.go b/ipld/unixfs/mod/dagmodifier.go
index f662a0a71..c075523f8 100644
--- a/ipld/unixfs/mod/dagmodifier.go
+++ b/ipld/unixfs/mod/dagmodifier.go
@@ -7,6 +7,7 @@ import (
 	"context"
 	"errors"
 	"io"
+	"time"
 
 	ft "github.com/ipfs/boxo/ipld/unixfs"
 	help "github.com/ipfs/boxo/ipld/unixfs/importer/helpers"
@@ -258,6 +259,9 @@ func (dm *DagModifier) modifyDag(n ipld.Node, offset uint64) (cid.Cid, error) {
 			}
 
 			// Update newly written node..
+			if !fsn.ModTime().IsZero() {
+				fsn.SetModTime(time.Now())
+			}
 			b, err := fsn.GetBytes()
 			if err != nil {
 				return cid.Cid{}, err
@@ -527,8 +531,17 @@ func (dm *DagModifier) dagTruncate(ctx context.Context, n ipld.Node, size uint64
 			if err != nil {
 				return nil, err
 			}
-			nd.SetData(ft.WrapData(fsn.Data()[:size]))
-			return nd, nil
+
+			fsn.SetData(fsn.Data()[:size])
+			if !fsn.ModTime().IsZero() {
+				fsn.SetModTime(time.Now())
+			}
+			data, err := fsn.GetBytes()
+			if err != nil {
+				return nil, err
+			}
+
+			return mdag.NodeWithData(data), nil
 		case *mdag.RawNode:
 			return mdag.NewRawNodeWPrefix(nd.RawData()[:size], nd.Cid().Prefix())
 		}
diff --git a/ipld/unixfs/pb/unixfs.pb.go b/ipld/unixfs/pb/unixfs.pb.go
index 805c11289..d02e110f2 100644
--- a/ipld/unixfs/pb/unixfs.pb.go
+++ b/ipld/unixfs/pb/unixfs.pb.go
@@ -82,6 +82,8 @@ type Data struct {
 	Blocksizes           []uint64       `protobuf:"varint,4,rep,name=blocksizes" json:"blocksizes,omitempty"`
 	HashType             *uint64        `protobuf:"varint,5,opt,name=hashType" json:"hashType,omitempty"`
 	Fanout               *uint64        `protobuf:"varint,6,opt,name=fanout" json:"fanout,omitempty"`
+	Mode                 *uint32        `protobuf:"varint,7,opt,name=mode" json:"mode,omitempty"`
+	Mtime                *IPFSTimestamp `protobuf:"bytes,8,opt,name=mtime" json:"mtime,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}       `json:"-"`
 	XXX_unrecognized     []byte         `json:"-"`
 	XXX_sizecache        int32          `json:"-"`
@@ -158,6 +160,20 @@ func (m *Data) GetFanout() uint64 {
 	return 0
 }
 
+func (m *Data) GetMode() uint32 {
+	if m != nil && m.Mode != nil {
+		return *m.Mode
+	}
+	return 0
+}
+
+func (m *Data) GetMtime() *IPFSTimestamp {
+	if m != nil {
+		return m.Mtime
+	}
+	return nil
+}
+
 type Metadata struct {
 	MimeType             *string  `protobuf:"bytes,1,opt,name=MimeType" json:"MimeType,omitempty"`
 	XXX_NoUnkeyedLiteral struct{} `json:"-"`
@@ -201,31 +217,91 @@ func (m *Metadata) GetMimeType() string {
 	return ""
 }
 
+// mostly copied from proto 3 - with int32 nanos changed to fixed32 for js-ipfs compatibility
+// https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/timestamp.proto
+type IPFSTimestamp struct {
+	// Represents seconds of UTC time since Unix epoch
+	// 1970-01-01T00:00:00Z. Must be from 0001-01-01T00:00:00Z to
+	// 9999-12-31T23:59:59Z inclusive.
+	Seconds *int64 `protobuf:"varint,1,req,name=seconds" json:"seconds,omitempty"`
+	// Non-negative fractions of a second at nanosecond resolution. Negative
+	// second values with fractions must still have non-negative nanos values
+	// that count forward in time. Must be from 0 to 999,999,999
+	// inclusive.
+	Nanos                *uint32  `protobuf:"fixed32,2,opt,name=nanos" json:"nanos,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
+}
+
+func (m *IPFSTimestamp) Reset()         { *m = IPFSTimestamp{} }
+func (m *IPFSTimestamp) String() string { return proto.CompactTextString(m) }
+func (*IPFSTimestamp) ProtoMessage()    {}
+func (*IPFSTimestamp) Descriptor() ([]byte, []int) {
+	return fileDescriptor_e2fd76cc44dfc7c3, []int{2}
+}
+func (m *IPFSTimestamp) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_IPFSTimestamp.Unmarshal(m, b)
+}
+func (m *IPFSTimestamp) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_IPFSTimestamp.Marshal(b, m, deterministic)
+}
+func (m *IPFSTimestamp) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_IPFSTimestamp.Merge(m, src)
+}
+func (m *IPFSTimestamp) XXX_Size() int {
+	return xxx_messageInfo_IPFSTimestamp.Size(m)
+}
+func (m *IPFSTimestamp) XXX_DiscardUnknown() {
+	xxx_messageInfo_IPFSTimestamp.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_IPFSTimestamp proto.InternalMessageInfo
+
+func (m *IPFSTimestamp) GetSeconds() int64 {
+	if m != nil && m.Seconds != nil {
+		return *m.Seconds
+	}
+	return 0
+}
+
+func (m *IPFSTimestamp) GetNanos() uint32 {
+	if m != nil && m.Nanos != nil {
+		return *m.Nanos
+	}
+	return 0
+}
+
 func init() {
 	proto.RegisterEnum("unixfs.v1.pb.Data_DataType", Data_DataType_name, Data_DataType_value)
 	proto.RegisterType((*Data)(nil), "unixfs.v1.pb.Data")
 	proto.RegisterType((*Metadata)(nil), "unixfs.v1.pb.Metadata")
+	proto.RegisterType((*IPFSTimestamp)(nil), "unixfs.pb.IPFSTimestamp")
 }
 
 func init() { proto.RegisterFile("unixfs.proto", fileDescriptor_e2fd76cc44dfc7c3) }
 
 var fileDescriptor_e2fd76cc44dfc7c3 = []byte{
-	// 267 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x4c, 0x90, 0x41, 0x4f, 0x83, 0x30,
-	0x18, 0x86, 0x05, 0xba, 0x0d, 0xbe, 0xa1, 0x69, 0xbe, 0x83, 0x21, 0x9a, 0x18, 0xc2, 0xc1, 0x70,
-	0xc2, 0xe8, 0x3f, 0xd0, 0x2c, 0xc6, 0x0b, 0x97, 0x6e, 0xf1, 0xe0, 0xc5, 0x94, 0xad, 0x84, 0x66,
-	0x8c, 0x12, 0xe8, 0x54, 0xfc, 0x1b, 0xfe, 0x61, 0x53, 0x18, 0xdb, 0x2e, 0x4d, 0x9e, 0xf6, 0x79,
-	0x9b, 0x37, 0x2f, 0xf8, 0xfb, 0x4a, 0xfe, 0xe4, 0x6d, 0x52, 0x37, 0x4a, 0x2b, 0x1c, 0xe9, 0xeb,
-	0x31, 0xa9, 0xb3, 0xe8, 0xcf, 0x06, 0xb2, 0xe0, 0x9a, 0xe3, 0x03, 0x90, 0x55, 0x57, 0x8b, 0xc0,
-	0x0a, 0xed, 0xf8, 0xea, 0xe9, 0x36, 0x39, 0xb7, 0x12, 0x63, 0xf4, 0x87, 0x51, 0x58, 0x2f, 0x22,
-	0x0e, 0xc1, 0xc0, 0x0e, 0xad, 0xd8, 0x67, 0xc3, 0x27, 0x37, 0xe0, 0xe6, 0xb2, 0x14, 0xad, 0xfc,
-	0x15, 0x81, 0x13, 0x5a, 0x31, 0x61, 0x47, 0xc6, 0x3b, 0x80, 0xac, 0x54, 0xeb, 0xad, 0x81, 0x36,
-	0x20, 0xa1, 0x13, 0x13, 0x76, 0x76, 0x63, 0xb2, 0x05, 0x6f, 0x8b, 0xbe, 0xc4, 0x64, 0xc8, 0x8e,
-	0x8c, 0xd7, 0x30, 0xcd, 0x79, 0xa5, 0xf6, 0x3a, 0x98, 0xf6, 0x2f, 0x07, 0x8a, 0xde, 0xc1, 0x1d,
-	0x5b, 0xe1, 0x0c, 0x1c, 0xc6, 0xbf, 0xe9, 0x05, 0x5e, 0x82, 0xb7, 0x90, 0x8d, 0x58, 0x6b, 0xd5,
-	0x74, 0xd4, 0x42, 0x17, 0xc8, 0xab, 0x2c, 0x05, 0xb5, 0xd1, 0x07, 0x37, 0x15, 0x9a, 0x6f, 0xb8,
-	0xe6, 0xd4, 0xc1, 0x39, 0xcc, 0x96, 0xdd, 0xae, 0x94, 0xd5, 0x96, 0x12, 0x93, 0x79, 0x7b, 0x4e,
-	0x57, 0xcb, 0x82, 0x37, 0x1b, 0x3a, 0x89, 0xee, 0x4f, 0xa6, 0xe9, 0x95, 0xca, 0x9d, 0x38, 0x8c,
-	0x63, 0xc5, 0x1e, 0x3b, 0xf2, 0xcb, 0xfc, 0xc3, 0x1b, 0x76, 0xfa, 0xac, 0xb3, 0xff, 0x00, 0x00,
-	0x00, 0xff, 0xff, 0xbd, 0x16, 0xf8, 0x45, 0x67, 0x01, 0x00, 0x00,
+	// 322 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x54, 0x91, 0x5f, 0x4b, 0xc3, 0x30,
+	0x14, 0xc5, 0xed, 0xbf, 0xb5, 0xbb, 0xdb, 0xa4, 0x5c, 0x44, 0x82, 0x0f, 0x52, 0xfa, 0x20, 0x7d,
+	0x90, 0x3e, 0xf8, 0x05, 0x44, 0x18, 0x43, 0x1f, 0x06, 0x92, 0x0d, 0xdf, 0xb3, 0x35, 0x63, 0x61,
+	0x4d, 0x33, 0x9a, 0x0c, 0x9d, 0x9f, 0xd3, 0x0f, 0x24, 0x49, 0xd7, 0xe9, 0x5e, 0x4a, 0x7f, 0xb9,
+	0xe7, 0x84, 0x73, 0x6e, 0x60, 0x7c, 0x68, 0xc4, 0xd7, 0x46, 0x97, 0xfb, 0x56, 0x19, 0x85, 0xc3,
+	0x9e, 0x56, 0xf9, 0x8f, 0x0f, 0xe1, 0x94, 0x19, 0x86, 0x8f, 0x10, 0x2e, 0x8f, 0x7b, 0x4e, 0xbc,
+	0xcc, 0x2f, 0xae, 0x9f, 0x48, 0x79, 0x96, 0x94, 0x76, 0xec, 0x3e, 0x76, 0x4e, 0x9d, 0x0a, 0xb1,
+	0x73, 0x11, 0x3f, 0xf3, 0x8a, 0x31, 0xed, 0x6e, 0xb8, 0x83, 0x64, 0x23, 0x6a, 0xae, 0xc5, 0x37,
+	0x27, 0x41, 0xe6, 0x15, 0x21, 0x3d, 0x33, 0xde, 0x03, 0xac, 0x6a, 0xb5, 0xde, 0x59, 0xd0, 0x24,
+	0xcc, 0x82, 0x22, 0xa4, 0xff, 0x4e, 0xac, 0x77, 0xcb, 0xf4, 0xd6, 0x25, 0x88, 0x3a, 0x6f, 0xcf,
+	0x78, 0x0b, 0x83, 0x0d, 0x6b, 0xd4, 0xc1, 0x90, 0x81, 0x9b, 0x9c, 0xc8, 0x66, 0x90, 0xaa, 0xe2,
+	0x24, 0xce, 0xbc, 0x62, 0x42, 0xdd, 0x3f, 0x96, 0x10, 0x49, 0x23, 0x24, 0x27, 0x49, 0xe6, 0x15,
+	0xa3, 0x8b, 0x1a, 0x6f, 0xef, 0xb3, 0xc5, 0x52, 0x48, 0xae, 0x0d, 0x93, 0x7b, 0xda, 0xc9, 0xf2,
+	0x0f, 0x48, 0xfa, 0x66, 0x18, 0x43, 0x40, 0xd9, 0x67, 0x7a, 0x85, 0x13, 0x18, 0x4e, 0x45, 0xcb,
+	0xd7, 0x46, 0xb5, 0xc7, 0xd4, 0xc3, 0x04, 0xc2, 0x99, 0xa8, 0x79, 0xea, 0xe3, 0x18, 0x92, 0x39,
+	0x37, 0xac, 0x62, 0x86, 0xa5, 0x01, 0x8e, 0x20, 0x5e, 0x1c, 0x65, 0x2d, 0x9a, 0x5d, 0x1a, 0x5a,
+	0xcf, 0xeb, 0xcb, 0x7c, 0xb9, 0xd8, 0xb2, 0xb6, 0x4a, 0xa3, 0xfc, 0xe1, 0x4f, 0x69, 0xbb, 0xcd,
+	0x85, 0xe4, 0xa7, 0xed, 0x7a, 0xc5, 0x90, 0x9e, 0x39, 0x7f, 0x86, 0xc9, 0x45, 0x2e, 0x24, 0x10,
+	0x6b, 0xbe, 0x56, 0x4d, 0xa5, 0xdd, 0x4b, 0x04, 0xb4, 0x47, 0xbc, 0x81, 0xa8, 0x61, 0x8d, 0xd2,
+	0x6e, 0xe7, 0x31, 0xed, 0xe0, 0x37, 0x00, 0x00, 0xff, 0xff, 0x36, 0xaf, 0xfa, 0x7c, 0xd9, 0x01,
+	0x00, 0x00,
 }
diff --git a/ipld/unixfs/pb/unixfs.proto b/ipld/unixfs/pb/unixfs.proto
index f65673f54..bd02aa410 100644
--- a/ipld/unixfs/pb/unixfs.proto
+++ b/ipld/unixfs/pb/unixfs.proto
@@ -21,8 +21,25 @@ message Data {
 
 	optional uint64 hashType = 5;
 	optional uint64 fanout = 6;
+    optional uint32 mode = 7;
+	optional IPFSTimestamp mtime = 8;
 }
 
 message Metadata {
 	optional string MimeType = 1;
 }
+
+// mostly copied from proto 3 - with int32 nanos changed to fixed32 for js-ipfs compatibility
+// https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/timestamp.proto
+message IPFSTimestamp {
+	// Represents seconds of UTC time since Unix epoch
+	// 1970-01-01T00:00:00Z. Must be from 0001-01-01T00:00:00Z to
+	// 9999-12-31T23:59:59Z inclusive.
+	required int64 seconds = 1;
+
+	// Non-negative fractions of a second at nanosecond resolution. Negative
+	// second values with fractions must still have non-negative nanos values
+	// that count forward in time. Must be from 0 to 999,999,999
+	// inclusive.
+	optional fixed32 nanos = 2;
+}
diff --git a/ipld/unixfs/unixfs.go b/ipld/unixfs/unixfs.go
index 4131df837..bdc54518f 100644
--- a/ipld/unixfs/unixfs.go
+++ b/ipld/unixfs/unixfs.go
@@ -6,10 +6,12 @@ package unixfs
 import (
 	"errors"
 	"fmt"
+	"os"
+	"time"
 
 	proto "github.com/gogo/protobuf/proto"
+	files "github.com/ipfs/boxo/files"
 	dag "github.com/ipfs/boxo/ipld/merkledag"
-
 	pb "github.com/ipfs/boxo/ipld/unixfs/pb"
 	ipld "github.com/ipfs/go-ipld-format"
 )
@@ -69,6 +71,22 @@ func FilePBData(data []byte, totalsize uint64) []byte {
 	return data
 }
 
+func FilePBDataWithStat(data []byte, totalsize uint64, mode os.FileMode, mtime time.Time) []byte {
+	pbfile := new(pb.Data)
+	typ := pb.Data_File
+	pbfile.Type = &typ
+	pbfile.Data = data
+	pbfile.Filesize = proto.Uint64(totalsize)
+
+	pbDataAddStat(pbfile, mode, mtime)
+
+	data, err := proto.Marshal(pbfile)
+	if err != nil {
+		panic(err)
+	}
+	return data
+}
+
 // FolderPBData returns Bytes that represent a Directory.
 func FolderPBData() []byte {
 	pbfile := new(pb.Data)
@@ -83,6 +101,36 @@ func FolderPBData() []byte {
 	return data
 }
 
+func FolderPBDataWithStat(mode os.FileMode, mtime time.Time) []byte {
+	pbfile := new(pb.Data)
+	typ := pb.Data_Directory
+	pbfile.Type = &typ
+
+	pbDataAddStat(pbfile, mode, mtime)
+
+	data, err := proto.Marshal(pbfile)
+	if err != nil {
+		//this really shouldnt happen, i promise
+		panic(err)
+	}
+	return data
+}
+
+func pbDataAddStat(data *pb.Data, mode os.FileMode, mtime time.Time) {
+	if mode != 0 {
+		data.Mode = proto.Uint32(files.ModePermsToUnixPerms(mode))
+	}
+	if !mtime.IsZero() {
+		data.Mtime = &pb.IPFSTimestamp{
+			Seconds: proto.Int64(mtime.Unix()),
+		}
+
+		if nanos := uint32(mtime.Nanosecond()); nanos > 0 {
+			data.Mtime.Nanos = &nanos
+		}
+	}
+}
+
 // WrapData marshals raw bytes into a `Data_Raw` type protobuf message.
 func WrapData(b []byte) []byte {
 	pbdata := new(pb.Data)
@@ -303,6 +351,93 @@ func (n *FSNode) IsDir() bool {
 	}
 }
 
+// Mode returns the optionally stored file permissions
+func (n *FSNode) Mode() (m os.FileMode) {
+	perms := n.format.GetMode() & 0xFFF
+	if perms != 0 {
+		m = files.UnixPermsToModePerms(perms)
+		switch n.Type() {
+		case pb.Data_Directory, pb.Data_HAMTShard:
+			m |= os.ModeDir
+		case pb.Data_Symlink:
+			m |= os.ModeSymlink
+		}
+	}
+	return m
+}
+
+// SetMode stores the given mode permissions, or nullifies stored permissions
+// if none were provided and there are no extended bits set.
+func (n *FSNode) SetMode(m os.FileMode) {
+	n.SetModeFromUnixPermissions(files.ModePermsToUnixPerms(m))
+}
+
+// SetModeFromUnixPermissions stores the given unix permissions, or nullifies stored permissions
+// if none were provided and there are no extended bits set.
+func (n *FSNode) SetModeFromUnixPermissions(unixPerms uint32) {
+	// preserve existing most significant 20 bits
+	newMode := (n.format.GetMode() & 0xFFFFF000) | (unixPerms & 0xFFF)
+
+	if unixPerms == 0 {
+		if newMode&0xFFFFF000 == 0 {
+			n.format.Mode = nil
+			return
+		}
+	}
+	n.format.Mode = &newMode
+}
+
+// ExtendedMode returns the 20 bits of extended file mode
+func (n *FSNode) ExtendedMode() uint32 {
+	return (n.format.GetMode() & 0xFFFFF000) >> 12
+}
+
+// SetExtendedMode stores the 20 bits of extended file mode, only the first
+// 20 bits of the `mode` argument are used, the remaining 12 bits are ignored.
+func (n *FSNode) SetExtendedMode(mode uint32) {
+	newMode := (mode << 12) | (0xFFF & n.format.GetMode())
+	if newMode == 0 {
+		n.format.Mode = nil
+	} else {
+		n.format.Mode = &newMode
+	}
+}
+
+// ModTime returns the stored last modified timestamp if available.
+func (n *FSNode) ModTime() time.Time {
+	ts := n.format.GetMtime()
+	if ts == nil || ts.Seconds == nil {
+		return time.Time{}
+	}
+	if ts.Nanos == nil {
+		return time.Unix(*ts.Seconds, 0)
+	}
+	if *ts.Nanos < 1 || *ts.Nanos > 999999999 {
+		return time.Time{}
+	}
+
+	return time.Unix(*ts.Seconds, int64(*ts.Nanos))
+}
+
+// SetModTime stores the given last modified timestamp, otherwise nullifies stored timestamp.
+func (n *FSNode) SetModTime(ts time.Time) {
+	if ts.IsZero() {
+		n.format.Mtime = nil
+		return
+	}
+
+	if n.format.Mtime == nil {
+		n.format.Mtime = &pb.IPFSTimestamp{}
+	}
+
+	n.format.Mtime.Seconds = proto.Int64(ts.Unix())
+	if ts.Nanosecond() > 0 {
+		n.format.Mtime.Nanos = proto.Uint32(uint32(ts.Nanosecond()))
+	} else {
+		n.format.Mtime.Nanos = nil
+	}
+}
+
 // Metadata is used to store additional FSNode information.
 type Metadata struct {
 	MimeType string
@@ -360,6 +495,10 @@ func EmptyDirNode() *dag.ProtoNode {
 	return dag.NodeWithData(FolderPBData())
 }
 
+func EmptyDirNodeWithStat(mode os.FileMode, mtime time.Time) *dag.ProtoNode {
+	return dag.NodeWithData(FolderPBDataWithStat(mode, mtime))
+}
+
 // EmptyFileNode creates an empty file Protonode.
 func EmptyFileNode() *dag.ProtoNode {
 	return dag.NodeWithData(FilePBData(nil, 0))
diff --git a/ipld/unixfs/unixfs_test.go b/ipld/unixfs/unixfs_test.go
index b785be8ad..4cbc22ca8 100644
--- a/ipld/unixfs/unixfs_test.go
+++ b/ipld/unixfs/unixfs_test.go
@@ -2,7 +2,9 @@ package unixfs
 
 import (
 	"bytes"
+	"os"
 	"testing"
+	"time"
 
 	proto "github.com/gogo/protobuf/proto"
 
@@ -183,3 +185,251 @@ func TestIsDir(t *testing.T) {
 		}
 	}
 }
+
+func (n *FSNode) getPbData(t *testing.T) *pb.Data {
+	b, err := n.GetBytes()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	pbn := new(pb.Data)
+	err = proto.Unmarshal(b, pbn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return pbn
+}
+
+func TestMode(t *testing.T) {
+	fsn := NewFSNode(TDirectory)
+	fsn.SetMode(1)
+	if !fsn.Mode().IsDir() {
+		t.Fatal("expected mode for directory")
+	}
+
+	fsn = NewFSNode(TSymlink)
+	fsn.SetMode(1)
+	if fsn.Mode()&os.ModeSymlink != os.ModeSymlink {
+		t.Fatal("expected mode for symlink")
+	}
+
+	fsn = NewFSNode(TFile)
+
+	// not stored
+	if fsn.Mode() != 0 {
+		t.Fatal("expected mode not to be set")
+	}
+
+	fileMode := os.FileMode(0640)
+	fsn.SetMode(fileMode)
+	if !fsn.Mode().IsRegular() {
+		t.Fatal("expected a regular file mode")
+	}
+	mode := fsn.Mode()
+
+	if mode&os.ModePerm != fileMode {
+		t.Fatalf("expected permissions to be %O but got %O", fileMode, mode&os.ModePerm)
+	}
+	if mode&0xFFFFF000 != 0 {
+		t.Fatalf("expected high-order 20 bits of mode to be clear but got %b", (mode&0xFFFFF000)>>12)
+	}
+
+	fsn.SetMode(fileMode | os.ModeSticky)
+	mode = fsn.Mode()
+	if mode&os.ModePerm != fileMode&os.ModePerm {
+		t.Fatalf("expected permissions to be %O but got %O", fileMode, mode&os.ModePerm)
+	}
+	if mode&os.ModeSticky == 0 {
+		t.Fatal("expected permissions to have sticky bit set")
+	}
+	if mode&os.ModeSetuid != 0 {
+		t.Fatal("expected permissions to have setuid bit unset")
+	}
+	if mode&os.ModeSetgid != 0 {
+		t.Fatal("expected permissions to have setgid bit unset")
+	}
+
+	fsn.SetMode(fileMode | os.ModeSticky | os.ModeSetuid)
+	mode = fsn.Mode()
+	if mode&os.ModePerm != fileMode&os.ModePerm {
+		t.Fatalf("expected permissions to be %O but got %O", fileMode, mode&os.ModePerm)
+	}
+	if mode&os.ModeSticky == 0 {
+		t.Fatal("expected permissions to have sticky bit set")
+	}
+	if mode&os.ModeSetuid == 0 {
+		t.Fatal("expected permissions to have setuid bit set")
+	}
+	if mode&os.ModeSetgid != 0 {
+		t.Fatal("expected permissions to have setgid bit unset")
+	}
+
+	fsn.SetMode(fileMode | os.ModeSetuid | os.ModeSetgid)
+	mode = fsn.Mode()
+	if mode&os.ModePerm != fileMode&os.ModePerm {
+		t.Fatalf("expected permissions to be %O but got %O", fileMode, mode&os.ModePerm)
+	}
+	if mode&os.ModeSticky != 0 {
+		t.Fatal("expected permissions to have sticky bit unset")
+	}
+	if mode&os.ModeSetuid == 0 {
+		t.Fatal("expected permissions to have setuid bit set")
+	}
+	if mode&os.ModeSetgid == 0 {
+		t.Fatal("expected permissions to have setgid bit set")
+	}
+
+	// check the internal format (unix permissions)
+	fsn.SetMode(fileMode | os.ModeSetuid | os.ModeSticky)
+	pbn := fsn.getPbData(t)
+	// unix perms setuid and sticky bits should also be set
+	expected := uint32(05000 | (fileMode & os.ModePerm))
+	if *pbn.Mode != expected {
+		t.Fatalf("expected stored permissions to be %O but got %O", expected, *pbn.Mode)
+	}
+
+	fsn.SetMode(0)
+	pbn = fsn.getPbData(t)
+	if pbn.Mode != nil {
+		t.Fatal("expected file mode to be unset")
+	}
+
+	fsn.SetExtendedMode(1)
+	fsn.SetMode(0)
+	pbn = fsn.getPbData(t)
+	if pbn.Mode == nil {
+		t.Fatal("expected extended mode to be preserved")
+	}
+}
+
+func TestExtendedMode(t *testing.T) {
+	fsn := NewFSNode(TFile)
+	fsn.SetMode(os.ModePerm | os.ModeSetuid | os.ModeSticky)
+	const expectedUnixMode = uint32(05777)
+
+	expectedExtMode := uint32(0xAAAAA)
+	fsn.SetExtendedMode(expectedExtMode)
+	extMode := fsn.ExtendedMode()
+	if extMode != expectedExtMode {
+		t.Fatalf("expected extended mode to be %X but got %X", expectedExtMode, extMode)
+	}
+	pbn := fsn.getPbData(t)
+	expectedPbMode := (expectedExtMode << 12) | (expectedUnixMode & 0xFFF)
+	if *pbn.Mode != expectedPbMode {
+		t.Fatalf("expected stored mode to be %b but got %b", expectedPbMode, *pbn.Mode)
+	}
+
+	expectedExtMode = uint32(0x55555)
+	fsn.SetExtendedMode(expectedExtMode)
+	extMode = fsn.ExtendedMode()
+	if extMode != expectedExtMode {
+		t.Fatalf("expected extended mode to be %X but got %X", expectedExtMode, extMode)
+	}
+	pbn = fsn.getPbData(t)
+	expectedPbMode = (expectedExtMode << 12) | (expectedUnixMode & 0xFFF)
+	if *pbn.Mode != expectedPbMode {
+		t.Fatalf("expected stored mode to be %b but got %b", expectedPbMode, *pbn.Mode)
+	}
+
+	// ignore bits 21..32
+	expectedExtMode = uint32(0xFFFFF)
+	fsn.SetExtendedMode(0xAAAFFFFF)
+	extMode = fsn.ExtendedMode()
+	if extMode != expectedExtMode {
+		t.Fatalf("expected extended mode to be %X but got %X", expectedExtMode, extMode)
+	}
+	pbn = fsn.getPbData(t)
+	expectedPbMode = (expectedExtMode << 12) | (expectedUnixMode & 0xFFF)
+	if *pbn.Mode != expectedPbMode {
+		t.Fatalf("expected raw mode to be %b but got %b", expectedPbMode, *pbn.Mode)
+	}
+
+	fsn.SetMode(0)
+	fsn.SetExtendedMode(0)
+	pbn = fsn.getPbData(t)
+	if pbn.Mode != nil {
+		t.Fatal("expected file mode to be unset")
+	}
+}
+
+func (n *FSNode) setPbModTime(seconds *int64, nanos *uint32) {
+	if n.format.Mtime == nil {
+		n.format.Mtime = &pb.IPFSTimestamp{}
+	}
+
+	n.format.Mtime.Seconds = seconds
+	n.format.Mtime.Nanos = nanos
+}
+
+func TestModTime(t *testing.T) {
+	tm := time.Now()
+	expectedUnix := tm.Unix()
+	n := NewFSNode(TFile)
+
+	// not stored
+	mt := n.ModTime()
+	if !mt.IsZero() {
+		t.Fatal("expected modification time not to be set")
+	}
+
+	// valid timestamps
+	n.SetModTime(tm)
+	mt = n.ModTime()
+	if !mt.Equal(tm) {
+		t.Fatalf("expected modification time to be %v but got %v", tm, mt)
+	}
+
+	tm = time.Unix(expectedUnix, 0)
+	n.SetModTime(tm)
+	pbn := n.getPbData(t)
+	if pbn.Mtime.Nanos != nil {
+		t.Fatal("expected nanoseconds to be nil")
+	}
+	mt = n.ModTime()
+	if !mt.Equal(tm) {
+		t.Fatalf("expected modification time to be %v but got %v", tm, mt)
+	}
+
+	tm = time.Unix(expectedUnix, 3489753)
+	n.SetModTime(tm)
+	mt = n.ModTime()
+	if !mt.Equal(tm) {
+		t.Fatalf("expected modification time to be %v but got %v", tm, mt)
+	}
+
+	tm = time.Time{}
+	n.SetModTime(tm)
+	pbn = n.getPbData(t)
+	if pbn.Mtime != nil {
+		t.Fatal("expected modification time to be unset")
+	}
+	mt = n.ModTime()
+	if !mt.Equal(tm) {
+		t.Fatalf("expected modification time to be %v but got %v", tm, mt)
+	}
+
+	n.setPbModTime(&expectedUnix, nil)
+	mt = n.ModTime()
+	if !mt.Equal(time.Unix(expectedUnix, 0)) {
+		t.Fatalf("expected modification time to be %v but got %v", time.Unix(expectedUnix, 0), mt)
+	}
+
+	// invalid timestamps
+	n.setPbModTime(nil, proto.Uint32(1000))
+	mt = n.ModTime()
+	if !mt.IsZero() {
+		t.Fatal("expected modification time not to be set")
+	}
+
+	n.setPbModTime(&expectedUnix, proto.Uint32(0))
+	mt = n.ModTime()
+	if !mt.IsZero() {
+		t.Fatal("expected modification time not to be set")
+	}
+
+	n.setPbModTime(&expectedUnix, proto.Uint32(1000000000))
+	mt = n.ModTime()
+	if !mt.IsZero() {
+		t.Fatal("expected modification time not to be set")
+	}
+}
diff --git a/mfs/dir.go b/mfs/dir.go
index 86c85d1c5..38302ac39 100644
--- a/mfs/dir.go
+++ b/mfs/dir.go
@@ -41,8 +41,6 @@ type Directory struct {
 	// UnixFS directory implementation used for creating,
 	// reading and editing directories.
 	unixfsDir uio.Directory
-
-	modTime time.Time
 }
 
 // NewDirectory constructs a new MFS directory.
@@ -64,7 +62,6 @@ func NewDirectory(ctx context.Context, name string, node ipld.Node, parent paren
 		ctx:          ctx,
 		unixfsDir:    db,
 		entriesCache: make(map[string]FSNode),
-		modTime:      time.Now(),
 	}, nil
 }
 
@@ -135,8 +132,6 @@ func (d *Directory) updateChild(c child) error {
 		return err
 	}
 
-	d.modTime = time.Now()
-
 	return nil
 }
 
@@ -292,6 +287,10 @@ func (d *Directory) ForEachEntry(ctx context.Context, f func(NodeListing) error)
 }
 
 func (d *Directory) Mkdir(name string) (*Directory, error) {
+	return d.MkdirWithOpts(name, MkdirOpts{})
+}
+
+func (d *Directory) MkdirWithOpts(name string, opts MkdirOpts) (*Directory, error) {
 	d.lock.Lock()
 	defer d.lock.Unlock()
 
@@ -307,7 +306,7 @@ func (d *Directory) Mkdir(name string) (*Directory, error) {
 		}
 	}
 
-	ndir := ft.EmptyDirNode()
+	ndir := ft.EmptyDirNodeWithStat(opts.Mode, opts.ModTime)
 	ndir.SetCidBuilder(d.GetCidBuilder())
 
 	err = d.dagService.Add(d.ctx, ndir)
@@ -367,7 +366,6 @@ func (d *Directory) AddChild(name string, nd ipld.Node) error {
 		return err
 	}
 
-	d.modTime = time.Now()
 	return nil
 }
 
@@ -427,3 +425,68 @@ func (d *Directory) GetNode() (ipld.Node, error) {
 
 	return nd.Copy(), err
 }
+
+func (d *Directory) SetMode(mode os.FileMode) error {
+	nd, err := d.GetNode()
+	if err != nil {
+		return err
+	}
+
+	fsn, err := ft.ExtractFSNode(nd)
+	if err != nil {
+		return err
+	}
+
+	fsn.SetMode(mode)
+	data, err := fsn.GetBytes()
+	if err != nil {
+		return err
+	}
+
+	return d.setNodeData(data, nd.Links())
+}
+
+func (d *Directory) SetModTime(ts time.Time) error {
+	nd, err := d.GetNode()
+	if err != nil {
+		return err
+	}
+
+	fsn, err := ft.ExtractFSNode(nd)
+	if err != nil {
+		return err
+	}
+
+	fsn.SetModTime(ts)
+	data, err := fsn.GetBytes()
+	if err != nil {
+		return err
+	}
+
+	return d.setNodeData(data, nd.Links())
+}
+
+func (d *Directory) setNodeData(data []byte, links []*ipld.Link) error {
+	nd := dag.NodeWithData(data)
+	nd.SetLinks(links)
+
+	err := d.dagService.Add(d.ctx, nd)
+	if err != nil {
+		return err
+	}
+
+	err = d.parent.updateChildEntry(child{d.name, nd})
+	if err != nil {
+		return err
+	}
+
+	d.lock.Lock()
+	defer d.lock.Unlock()
+	db, err := uio.NewDirectoryFromNode(d.dagService, nd)
+	if err != nil {
+		return err
+	}
+	d.unixfsDir = db
+
+	return nil
+}
diff --git a/mfs/file.go b/mfs/file.go
index 56c2b0046..ef8ce5dfa 100644
--- a/mfs/file.go
+++ b/mfs/file.go
@@ -3,7 +3,9 @@ package mfs
 import (
 	"context"
 	"errors"
+	"os"
 	"sync"
+	"time"
 
 	dag "github.com/ipfs/boxo/ipld/merkledag"
 	ft "github.com/ipfs/boxo/ipld/unixfs"
@@ -177,3 +179,91 @@ func (fi *File) Sync() error {
 func (fi *File) Type() NodeType {
 	return TFile
 }
+
+func (fi *File) Mode() (os.FileMode, error) {
+	fi.nodeLock.RLock()
+	defer fi.nodeLock.RUnlock()
+
+	nd, err := fi.GetNode()
+	if err == nil {
+		fsn, err := ft.ExtractFSNode(nd)
+		if err == nil {
+			return fsn.Mode() & 0xFFF, nil
+		}
+	}
+
+	return 0, err
+}
+
+func (fi *File) SetMode(mode os.FileMode) error {
+	nd, err := fi.GetNode()
+	if err != nil {
+		return err
+	}
+
+	fsn, err := ft.ExtractFSNode(nd)
+	if err != nil {
+		return err
+	}
+
+	fsn.SetMode(mode)
+	data, err := fsn.GetBytes()
+	if err != nil {
+		return err
+	}
+
+	return fi.setNodeData(data)
+}
+
+// ModTime returns the files' last modification time
+func (fi *File) ModTime() (time.Time, error) {
+	fi.nodeLock.RLock()
+	defer fi.nodeLock.RUnlock()
+
+	nd, err := fi.GetNode()
+	if err == nil {
+		fsn, err := ft.ExtractFSNode(nd)
+		if err == nil {
+			return fsn.ModTime(), nil
+		}
+	}
+
+	return time.Time{}, err
+}
+
+// SetModTime sets the files' last modification time
+func (fi *File) SetModTime(ts time.Time) error {
+	nd, err := fi.GetNode()
+	if err != nil {
+		return err
+	}
+
+	fsn, err := ft.ExtractFSNode(nd)
+	if err != nil {
+		return err
+	}
+
+	fsn.SetModTime(ts)
+	data, err := fsn.GetBytes()
+	if err != nil {
+		return err
+	}
+
+	return fi.setNodeData(data)
+}
+
+func (fi *File) setNodeData(data []byte) error {
+	nd := dag.NodeWithData(data)
+	err := fi.inode.dagService.Add(context.TODO(), nd)
+	if err != nil {
+		return err
+	}
+
+	fi.nodeLock.Lock()
+	defer fi.nodeLock.Unlock()
+	fi.node = nd
+	parent := fi.inode.parent
+	name := fi.inode.name
+
+	return parent.updateChildEntry(child{name, fi.node})
+}
diff --git a/mfs/mfs_test.go b/mfs/mfs_test.go
index eb5585a64..8497dbb0e 100644
--- a/mfs/mfs_test.go
+++ b/mfs/mfs_test.go
@@ -511,7 +511,19 @@ func TestMfsFile(t *testing.T) {
 	fi := fsn.(*File)
 
 	if fi.Type() != TFile {
-		t.Fatal("some is seriously wrong here")
+		t.Fatal("something is seriously wrong here")
+	}
+
+	if m, err := fi.Mode(); err != nil {
+		t.Fatal("failed to get file mode: ", err)
+	} else if m != 0 {
+		t.Fatal("mode should not be set on a new file")
+	}
+
+	if ts, err := fi.ModTime(); err != nil {
+		t.Fatal("failed to get file mtime: ", err)
+	} else if !ts.IsZero() {
+		t.Fatal("modification time should not be set on a new file")
 	}
 
 	wfd, err := fi.Open(Flags{Read: true, Write: true, Sync: true})
@@ -615,6 +627,12 @@ func TestMfsFile(t *testing.T) {
 		t.Fatal(err)
 	}
 
+	if ts, err := fi.ModTime(); err != nil {
+		t.Fatal("failed to get file mtime: ", err)
+	} else if !ts.IsZero() {
+		t.Fatal("file with unset modification time should not update modification time")
+	}
+
 	// make sure we can get node. TODO: verify it later
 	_, err = fi.GetNode()
 	if err != nil {
@@ -622,6 +640,141 @@ func TestMfsFile(t *testing.T) {
 	}
 }
 
+func TestMfsModeAndModTime(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	ds, rt := setupRoot(ctx, t)
+	rootdir := rt.GetDirectory()
+	nd := getRandFile(t, ds, 1000)
+
+	err := rootdir.AddChild("file", nd)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fsn, err := rootdir.Child("file")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	fi := fsn.(*File)
+
+	if fi.Type() != TFile {
+		t.Fatal("something is seriously wrong here")
+	}
+
+	var mode os.FileMode
+	ts, ts2 := time.Now(), time.Time{}
+
+	// can set mode
+	if err = fi.SetMode(0644); err == nil {
+		if mode, err = fi.Mode(); mode != 0644 {
+			t.Fatal("failed to get correct mode of file")
+		}
+	}
+	if err != nil {
+		t.Fatal("failed to check file mode: ", err)
+	}
+
+	// can set last modification time
+	if err = fi.SetModTime(ts); err == nil {
+		if ts2, err = fi.ModTime(); !ts2.Equal(ts) {
+			t.Fatal("failed to get correct modification time of file")
+		}
+	}
+	if err != nil {
+		t.Fatal("failed to check file modification time: ", err)
+	}
+
+	// test modification time update after write (on closing file)
+	wfd, err := fi.Open(Flags{Read: false, Write: true, Sync: true})
+	if err != nil {
+		t.Fatal(err)
+	}
+	_, err = wfd.Write([]byte("test"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = wfd.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+	ts2, err = fi.ModTime()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !ts2.After(ts) {
+		t.Fatal("modification time should be updated after file write")
+	}
+
+	// writeAt
+	ts = ts2
+	wfd, err = fi.Open(Flags{Read: false, Write: true, Sync: true})
+	if err != nil {
+		t.Fatal(err)
+	}
+	_, err = wfd.WriteAt([]byte("test"), 42)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = wfd.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+	ts2, err = fi.ModTime()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !ts2.After(ts) {
+		t.Fatal("modification time should be updated after file writeAt")
+	}
+
+	// truncate (shrink)
+	ts = ts2
+	wfd, err = fi.Open(Flags{Read: false, Write: true, Sync: true})
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = wfd.Truncate(100)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = wfd.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+	ts2, err = fi.ModTime()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !ts2.After(ts) {
+		t.Fatal("modification time should be updated after file truncate (shrink)")
+	}
+
+	// truncate (expand)
+	ts = ts2
+	wfd, err = fi.Open(Flags{Read: false, Write: true, Sync: true})
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = wfd.Truncate(1500)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = wfd.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+	ts2, err = fi.ModTime()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !ts2.After(ts) {
+		t.Fatal("modification time should be updated after file truncate (expand)")
+	}
+}
+
 func TestMfsDirListNames(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
diff --git a/mfs/ops.go b/mfs/ops.go
index 693264704..09dbab00f 100644
--- a/mfs/ops.go
+++ b/mfs/ops.go
@@ -7,6 +7,7 @@ import (
 	"os"
 	gopath "path"
 	"strings"
+	"time"
 
 	cid "github.com/ipfs/go-cid"
 	ipld "github.com/ipfs/go-ipld-format"
@@ -122,6 +123,8 @@ type MkdirOpts struct {
 	Mkparents  bool
 	Flush      bool
 	CidBuilder cid.Builder
+	Mode       os.FileMode
+	ModTime    time.Time
 }
 
 // Mkdir creates a directory at 'path' under the directory 'd', creating
@@ -171,7 +174,7 @@ func Mkdir(r *Root, pth string, opts MkdirOpts) error {
 		cur = next
 	}
 
-	final, err := cur.Mkdir(parts[len(parts)-1])
+	final, err := cur.MkdirWithOpts(parts[len(parts)-1], opts)
 	if err != nil {
 		if !opts.Mkparents || err != os.ErrExist || final == nil {
 			return err
@@ -243,3 +246,21 @@ func FlushPath(ctx context.Context, rt *Root, pth string) (ipld.Node, error) {
 	rt.repub.WaitPub(ctx)
 	return nd.GetNode()
 }
+
+func Chmod(rt *Root, pth string, mode os.FileMode) error {
+	nd, err := Lookup(rt, pth)
+	if err != nil {
+		return err
+	}
+
+	return nd.SetMode(mode)
+}
+
+func Touch(rt *Root, pth string, ts time.Time) error {
+	nd, err := Lookup(rt, pth)
+	if err != nil {
+		return err
+	}
+
+	return nd.SetModTime(ts)
+}
diff --git a/mfs/root.go b/mfs/root.go
index c08d2d053..5a7cb7ed1 100644
--- a/mfs/root.go
+++ b/mfs/root.go
@@ -7,6 +7,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"os"
 	"time"
 
 	dag "github.com/ipfs/boxo/ipld/merkledag"
@@ -73,6 +74,8 @@ type FSNode interface {
 
 	Flush() error
 	Type() NodeType
+	SetModTime(ts time.Time) error
+	SetMode(mode os.FileMode) error
 }
 
 // IsDir checks whether the FSNode is dir type

From 0686a87d44a55a52ef82d4b04408916f7e05a7a7 Mon Sep 17 00:00:00 2001
From: gammazero <11790789+gammazero@users.noreply.github.com>
Date: Mon, 12 Aug 2024 20:07:44 -0700
Subject: [PATCH 2/5] lint fix

---
 mfs/mfs_test.go | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/mfs/mfs_test.go b/mfs/mfs_test.go
index 8497dbb0e..4793ae141 100644
--- a/mfs/mfs_test.go
+++ b/mfs/mfs_test.go
@@ -665,7 +665,7 @@ func TestMfsModeAndModTime(t *testing.T) {
 	}
 
 	var mode os.FileMode
-	ts, ts2 := time.Now(), time.Time{}
+	ts, _ := time.Now(), time.Time{}
 
 	// can set mode
 	if err = fi.SetMode(0644); err == nil {
@@ -679,7 +679,11 @@ func TestMfsModeAndModTime(t *testing.T) {
 
 	// can set last modification time
 	if err = fi.SetModTime(ts); err == nil {
-		if ts2, err = fi.ModTime(); !ts2.Equal(ts) {
+		ts2, err := fi.ModTime()
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !ts2.Equal(ts) {
 			t.Fatal("failed to get correct modification time of file")
 		}
 	}
@@ -700,7 +704,7 @@ func TestMfsModeAndModTime(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	ts2, err = fi.ModTime()
+	ts2, err := fi.ModTime()
 	if err != nil {
 		t.Fatal(err)
 	}

From bfa8674d96906cabba270d4f64e45f0dccce5eee Mon Sep 17 00:00:00 2001
From: gammazero <11790789+gammazero@users.noreply.github.com>
Date: Mon, 12 Aug 2024 20:14:48 -0700
Subject: [PATCH 3/5] fix windows test

---
 mfs/mfs_test.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mfs/mfs_test.go b/mfs/mfs_test.go
index 4793ae141..223830d18 100644
--- a/mfs/mfs_test.go
+++ b/mfs/mfs_test.go
@@ -11,6 +11,7 @@ import (
 	"math/rand"
 	"os"
 	gopath "path"
+	"runtime"
 	"sort"
 	"strings"
 	"sync"
@@ -692,6 +693,9 @@ func TestMfsModeAndModTime(t *testing.T) {
 	}
 
 	// test modification time update after write (on closing file)
+	if runtime.GOOS == "windows" {
+		time.Sleep(3 * time.Second) // for os with low-res mod time.
+	}
 	wfd, err := fi.Open(Flags{Read: false, Write: true, Sync: true})
 	if err != nil {
 		t.Fatal(err)

From 738001b382b13a51cf37501d475094c04f3f8086 Mon Sep 17 00:00:00 2001
From: gammazero <11790789+gammazero@users.noreply.github.com>
Date: Mon, 12 Aug 2024 20:33:47 -0700
Subject: [PATCH 4/5] Fix windows tests for modtime

---
 mfs/mfs_test.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/mfs/mfs_test.go b/mfs/mfs_test.go
index 223830d18..80d0026a1 100644
--- a/mfs/mfs_test.go
+++ b/mfs/mfs_test.go
@@ -718,6 +718,9 @@ func TestMfsModeAndModTime(t *testing.T) {
 
 	// writeAt
 	ts = ts2
+	if runtime.GOOS == "windows" {
+		time.Sleep(3 * time.Second) // for os with low-res mod time.
+	}
 	wfd, err = fi.Open(Flags{Read: false, Write: true, Sync: true})
 	if err != nil {
 		t.Fatal(err)
@@ -740,6 +743,9 @@ func TestMfsModeAndModTime(t *testing.T) {
 
 	// truncate (shrink)
 	ts = ts2
+	if runtime.GOOS == "windows" {
+		time.Sleep(3 * time.Second) // for os with low-res mod time.
+	}
 	wfd, err = fi.Open(Flags{Read: false, Write: true, Sync: true})
 	if err != nil {
 		t.Fatal(err)
@@ -762,6 +768,9 @@ func TestMfsModeAndModTime(t *testing.T) {
 
 	// truncate (expand)
 	ts = ts2
+	if runtime.GOOS == "windows" {
+		time.Sleep(3 * time.Second) // for os with low-res mod time.
+	}
 	wfd, err = fi.Open(Flags{Read: false, Write: true, Sync: true})
 	if err != nil {
 		t.Fatal(err)

From 1b5bb03a0b963cbc2109bae66f56ccd57f7314a9 Mon Sep 17 00:00:00 2001
From: gammazero <11790789+gammazero@users.noreply.github.com>
Date: Mon, 12 Aug 2024 20:48:11 -0700
Subject: [PATCH 5/5] fix more windows tests

---
 ipld/unixfs/importer/trickle/trickle_test.go | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/ipld/unixfs/importer/trickle/trickle_test.go b/ipld/unixfs/importer/trickle/trickle_test.go
index 61899c9ff..d495fd208 100644
--- a/ipld/unixfs/importer/trickle/trickle_test.go
+++ b/ipld/unixfs/importer/trickle/trickle_test.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	mrand "math/rand"
+	"runtime"
 	"testing"
 	"time"
 
@@ -678,14 +679,17 @@ func TestAppendWithModTime(t *testing.T) {
 	const nbytes = 128 * 1024
 
 	timestamp := time.Now()
-	ds := mdtest.Mock()
 	buf := random.Bytes(nbytes)
 
 	nd := new(merkledag.ProtoNode)
 	nd.SetData(ft.FilePBDataWithStat(buf[:nbytes/2], nbytes/2, 0, timestamp))
 
+	if runtime.GOOS == "windows" {
+		time.Sleep(3 * time.Second) // for os with low-res mod time.
+	}
+
 	dbp := &h.DagBuilderParams{
-		Dagserv:  ds,
+		Dagserv:  mdtest.Mock(),
 		Maxlinks: h.DefaultLinksPerBlock,
 	}
 
@@ -710,12 +714,15 @@ func TestAppendWithModTime(t *testing.T) {
 
 func TestAppendToEmptyWithModTime(t *testing.T) {
 	timestamp := time.Now()
-	ds := mdtest.Mock()
 	nd := new(merkledag.ProtoNode)
 	nd.SetData(ft.FilePBDataWithStat(nil, 0, 0, timestamp))
 
+	if runtime.GOOS == "windows" {
+		time.Sleep(3 * time.Second) // for os with low-res mod time.
+	}
+
 	dbp := &h.DagBuilderParams{
-		Dagserv:  ds,
+		Dagserv:  mdtest.Mock(),
 		Maxlinks: h.DefaultLinksPerBlock,
 	}