Merge branch 'master' into ip-forwarding

- Merges aleksej-paschenko's with HEAD
- Adds vfs2 support for ip_forward

21 files changed, 1045 insertions, 683 deletions

diff --git a/pkg/p9/BUILD b/pkg/p9/BUILD
index f32244c69..8904afad9 100644
--- a/pkg/p9/BUILD
+++ b/pkg/p9/BUILD
@@ -1,5 +1,4 @@
-load("//tools/go_stateify:defs.bzl", "go_library")
-load("@io_bazel_rules_go//go:def.bzl", "go_test")
+load("//tools:defs.bzl", "go_library", "go_test")
 
 package(
     default_visibility = ["//visibility:public"],
@@ -17,18 +16,18 @@ go_library(
         "messages.go",
         "p9.go",
         "path_tree.go",
-        "pool.go",
         "server.go",
         "transport.go",
         "transport_flipcall.go",
         "version.go",
     ],
-    importpath = "gvisor.dev/gvisor/pkg/p9",
     deps = [
         "//pkg/fd",
         "//pkg/fdchannel",
         "//pkg/flipcall",
         "//pkg/log",
+        "//pkg/pool",
+        "//pkg/sync",
         "//pkg/unet",
         "@org_golang_x_sys//unix:go_default_library",
     ],
@@ -42,11 +41,10 @@ go_test(
         "client_test.go",
         "messages_test.go",
         "p9_test.go",
-        "pool_test.go",
         "transport_test.go",
         "version_test.go",
     ],
-    embed = [":p9"],
+    library = ":p9",
     deps = [
         "//pkg/fd",
         "//pkg/unet",
diff --git a/pkg/p9/buffer.go b/pkg/p9/buffer.go
index 249536d8a..6a4951821 100644
--- a/pkg/p9/buffer.go
+++ b/pkg/p9/buffer.go
@@ -20,16 +20,16 @@ import (
 
 // encoder is used for messages and 9P primitives.
 type encoder interface {
-	// Decode decodes from the given buffer. Decode may be called more than once
+	// decode decodes from the given buffer. decode may be called more than once
 	// to reuse the instance. It must clear any previous state.
 	//
 	// This may not fail, exhaustion will be recorded in the buffer.
-	Decode(b *buffer)
+	decode(b *buffer)
 
-	// Encode encodes to the given buffer.
+	// encode encodes to the given buffer.
 	//
 	// This may not fail.
-	Encode(b *buffer)
+	encode(b *buffer)
 }
 
 // order is the byte order used for encoding.
@@ -39,7 +39,7 @@ var order = binary.LittleEndian
 //
 // This is passed to the encoder methods.
 type buffer struct {
-	// data is the underlying data. This may grow during Encode.
+	// data is the underlying data. This may grow during encode.
 	data []byte
 
 	// overflow indicates whether an overflow has occurred.
diff --git a/pkg/p9/client.go b/pkg/p9/client.go
index 221516c6c..71e944c30 100644
--- a/pkg/p9/client.go
+++ b/pkg/p9/client.go
@@ -17,12 +17,13 @@ package p9
 import (
 	"errors"
 	"fmt"
-	"sync"
 	"syscall"
 
 	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/flipcall"
 	"gvisor.dev/gvisor/pkg/log"
+	"gvisor.dev/gvisor/pkg/pool"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/unet"
 )
 
@@ -74,10 +75,10 @@ type Client struct {
 	socket *unet.Socket
 
 	// tagPool is the collection of available tags.
-	tagPool pool
+	tagPool pool.Pool
 
 	// fidPool is the collection of available fids.
-	fidPool pool
+	fidPool pool.Pool
 
 	// messageSize is the maximum total size of a message.
 	messageSize uint32
@@ -155,8 +156,8 @@ func NewClient(socket *unet.Socket, messageSize uint32, version string) (*Client
 	}
 	c := &Client{
 		socket:      socket,
-		tagPool:     pool{start: 1, limit: uint64(NoTag)},
-		fidPool:     pool{start: 1, limit: uint64(NoFID)},
+		tagPool:     pool.Pool{Start: 1, Limit: uint64(NoTag)},
+		fidPool:     pool.Pool{Start: 1, Limit: uint64(NoFID)},
 		pending:     make(map[Tag]*response),
 		recvr:       make(chan bool, 1),
 		messageSize: messageSize,
@@ -173,7 +174,7 @@ func NewClient(socket *unet.Socket, messageSize uint32, version string) (*Client
 		// our sendRecv function to use that functionality.  Otherwise,
 		// we stick to sendRecvLegacy.
 		rversion := Rversion{}
-		err := c.sendRecvLegacy(&Tversion{
+		_, err := c.sendRecvLegacy(&Tversion{
 			Version: versionString(requested),
 			MSize:   messageSize,
 		}, &rversion)
@@ -218,11 +219,11 @@ func NewClient(socket *unet.Socket, messageSize uint32, version string) (*Client
 			c.sendRecv = c.sendRecvChannel
 		} else {
 			// Channel setup failed; fallback.
-			c.sendRecv = c.sendRecvLegacy
+			c.sendRecv = c.sendRecvLegacySyscallErr
 		}
 	} else {
 		// No channels available: use the legacy mechanism.
-		c.sendRecv = c.sendRecvLegacy
+		c.sendRecv = c.sendRecvLegacySyscallErr
 	}
 
 	// Ensure that the socket and channels are closed when the socket is shut
@@ -304,7 +305,7 @@ func (c *Client) openChannel(id int) error {
 	)
 
 	// Open the data channel.
-	if err := c.sendRecvLegacy(&Tchannel{
+	if _, err := c.sendRecvLegacy(&Tchannel{
 		ID:      uint32(id),
 		Control: 0,
 	}, &rchannel0); err != nil {
@@ -318,7 +319,7 @@ func (c *Client) openChannel(id int) error {
 	defer rchannel0.FilePayload().Close()
 
 	// Open the channel for file descriptors.
-	if err := c.sendRecvLegacy(&Tchannel{
+	if _, err := c.sendRecvLegacy(&Tchannel{
 		ID:      uint32(id),
 		Control: 1,
 	}, &rchannel1); err != nil {
@@ -430,13 +431,28 @@ func (c *Client) waitAndRecv(done chan error) error {
 	}
 }
 
+// sendRecvLegacySyscallErr is a wrapper for sendRecvLegacy that converts all
+// non-syscall errors to EIO.
+func (c *Client) sendRecvLegacySyscallErr(t message, r message) error {
+	received, err := c.sendRecvLegacy(t, r)
+	if !received {
+		log.Warningf("p9.Client.sendRecvChannel: %v", err)
+		return syscall.EIO
+	}
+	return err
+}
+
 // sendRecvLegacy performs a roundtrip message exchange.
 //
+// sendRecvLegacy returns true if a message was received. This allows us to
+// differentiate between failed receives and successful receives where the
+// response was an error message.
+//
 // This is called by internal functions.
-func (c *Client) sendRecvLegacy(t message, r message) error {
+func (c *Client) sendRecvLegacy(t message, r message) (bool, error) {
 	tag, ok := c.tagPool.Get()
 	if !ok {
-		return ErrOutOfTags
+		return false, ErrOutOfTags
 	}
 	defer c.tagPool.Put(tag)
 
@@ -456,12 +472,12 @@ func (c *Client) sendRecvLegacy(t message, r message) error {
 	err := send(c.socket, Tag(tag), t)
 	c.sendMu.Unlock()
 	if err != nil {
-		return err
+		return false, err
 	}
 
 	// Co-ordinate with other receivers.
 	if err := c.waitAndRecv(resp.done); err != nil {
-		return err
+		return false, err
 	}
 
 	// Is it an error message?
@@ -469,14 +485,14 @@ func (c *Client) sendRecvLegacy(t message, r message) error {
 	// For convenience, we transform these directly
 	// into errors. Handlers need not handle this case.
 	if rlerr, ok := resp.r.(*Rlerror); ok {
-		return syscall.Errno(rlerr.Error)
+		return true, syscall.Errno(rlerr.Error)
 	}
 
 	// At this point, we know it matches.
 	//
 	// Per recv call above, we will only allow a type
 	// match (and give our r) or an instance of Rlerror.
-	return nil
+	return true, nil
 }
 
 // sendRecvChannel uses channels to send a message.
@@ -485,7 +501,7 @@ func (c *Client) sendRecvChannel(t message, r message) error {
 	c.channelsMu.Lock()
 	if len(c.availableChannels) == 0 {
 		c.channelsMu.Unlock()
-		return c.sendRecvLegacy(t, r)
+		return c.sendRecvLegacySyscallErr(t, r)
 	}
 	idx := len(c.availableChannels) - 1
 	ch := c.availableChannels[idx]
@@ -525,7 +541,11 @@ func (c *Client) sendRecvChannel(t message, r message) error {
 	}
 
 	// Parse the server's response.
-	_, retErr := ch.recv(r, rsz)
+	resp, retErr := ch.recv(r, rsz)
+	if resp == nil {
+		log.Warningf("p9.Client.sendRecvChannel: p9.channel.recv: %v", retErr)
+		retErr = syscall.EIO
+	}
 
 	// Release the channel.
 	c.channelsMu.Lock()
diff --git a/pkg/p9/client_file.go b/pkg/p9/client_file.go
index a6cc0617e..2ee07b664 100644
--- a/pkg/p9/client_file.go
+++ b/pkg/p9/client_file.go
@@ -17,7 +17,6 @@ package p9
 import (
 	"fmt"
 	"io"
-	"runtime"
 	"sync/atomic"
 	"syscall"
 
@@ -45,15 +44,10 @@ func (c *Client) Attach(name string) (File, error) {
 
 // newFile returns a new client file.
 func (c *Client) newFile(fid FID) *clientFile {
-	cf := &clientFile{
+	return &clientFile{
 		client: c,
 		fid:    fid,
 	}
-
-	// Make sure the file is closed.
-	runtime.SetFinalizer(cf, (*clientFile).Close)
-
-	return cf
 }
 
 // clientFile is provided to clients.
@@ -171,6 +165,68 @@ func (c *clientFile) SetAttr(valid SetAttrMask, attr SetAttr) error {
 	return c.client.sendRecv(&Tsetattr{FID: c.fid, Valid: valid, SetAttr: attr}, &Rsetattr{})
 }
 
+// GetXattr implements File.GetXattr.
+func (c *clientFile) GetXattr(name string, size uint64) (string, error) {
+	if atomic.LoadUint32(&c.closed) != 0 {
+		return "", syscall.EBADF
+	}
+	if !versionSupportsGetSetXattr(c.client.version) {
+		return "", syscall.EOPNOTSUPP
+	}
+
+	rgetxattr := Rgetxattr{}
+	if err := c.client.sendRecv(&Tgetxattr{FID: c.fid, Name: name, Size: size}, &rgetxattr); err != nil {
+		return "", err
+	}
+
+	return rgetxattr.Value, nil
+}
+
+// SetXattr implements File.SetXattr.
+func (c *clientFile) SetXattr(name, value string, flags uint32) error {
+	if atomic.LoadUint32(&c.closed) != 0 {
+		return syscall.EBADF
+	}
+	if !versionSupportsGetSetXattr(c.client.version) {
+		return syscall.EOPNOTSUPP
+	}
+
+	return c.client.sendRecv(&Tsetxattr{FID: c.fid, Name: name, Value: value, Flags: flags}, &Rsetxattr{})
+}
+
+// ListXattr implements File.ListXattr.
+func (c *clientFile) ListXattr(size uint64) (map[string]struct{}, error) {
+	if atomic.LoadUint32(&c.closed) != 0 {
+		return nil, syscall.EBADF
+	}
+	if !versionSupportsListRemoveXattr(c.client.version) {
+		return nil, syscall.EOPNOTSUPP
+	}
+
+	rlistxattr := Rlistxattr{}
+	if err := c.client.sendRecv(&Tlistxattr{FID: c.fid, Size: size}, &rlistxattr); err != nil {
+		return nil, err
+	}
+
+	xattrs := make(map[string]struct{}, len(rlistxattr.Xattrs))
+	for _, x := range rlistxattr.Xattrs {
+		xattrs[x] = struct{}{}
+	}
+	return xattrs, nil
+}
+
+// RemoveXattr implements File.RemoveXattr.
+func (c *clientFile) RemoveXattr(name string) error {
+	if atomic.LoadUint32(&c.closed) != 0 {
+		return syscall.EBADF
+	}
+	if !versionSupportsListRemoveXattr(c.client.version) {
+		return syscall.EOPNOTSUPP
+	}
+
+	return c.client.sendRecv(&Tremovexattr{FID: c.fid, Name: name}, &Rremovexattr{})
+}
+
 // Allocate implements File.Allocate.
 func (c *clientFile) Allocate(mode AllocateMode, offset, length uint64) error {
 	if atomic.LoadUint32(&c.closed) != 0 {
@@ -192,7 +248,6 @@ func (c *clientFile) Remove() error {
 	if !atomic.CompareAndSwapUint32(&c.closed, 0, 1) {
 		return syscall.EBADF
 	}
-	runtime.SetFinalizer(c, nil)
 
 	// Send the remove message.
 	if err := c.client.sendRecv(&Tremove{FID: c.fid}, &Rremove{}); err != nil {
@@ -214,7 +269,6 @@ func (c *clientFile) Close() error {
 	if !atomic.CompareAndSwapUint32(&c.closed, 0, 1) {
 		return syscall.EBADF
 	}
-	runtime.SetFinalizer(c, nil)
 
 	// Send the close message.
 	if err := c.client.sendRecv(&Tclunk{FID: c.fid}, &Rclunk{}); err != nil {
diff --git a/pkg/p9/client_test.go b/pkg/p9/client_test.go
index 29a0afadf..b78fdab7a 100644
--- a/pkg/p9/client_test.go
+++ b/pkg/p9/client_test.go
@@ -62,6 +62,8 @@ func TestVersion(t *testing.T) {
 }
 
 func benchmarkSendRecv(b *testing.B, fn func(c *Client) func(message, message) error) {
+	b.ReportAllocs()
+
 	// See above.
 	serverSocket, clientSocket, err := unet.SocketPair(false)
 	if err != nil {
@@ -96,7 +98,12 @@ func benchmarkSendRecv(b *testing.B, fn func(c *Client) func(message, message) e
 }
 
 func BenchmarkSendRecvLegacy(b *testing.B) {
-	benchmarkSendRecv(b, func(c *Client) func(message, message) error { return c.sendRecvLegacy })
+	benchmarkSendRecv(b, func(c *Client) func(message, message) error {
+		return func(t message, r message) error {
+			_, err := c.sendRecvLegacy(t, r)
+			return err
+		}
+	})
 }
 
 func BenchmarkSendRecvChannel(b *testing.B) {
diff --git a/pkg/p9/file.go b/pkg/p9/file.go
index 907445e15..cab35896f 100644
--- a/pkg/p9/file.go
+++ b/pkg/p9/file.go
@@ -89,6 +89,38 @@ type File interface {
 	// On the server, SetAttr has a write concurrency guarantee.
 	SetAttr(valid SetAttrMask, attr SetAttr) error
 
+	// GetXattr returns extended attributes of this node.
+	//
+	// Size indicates the size of the buffer that has been allocated to hold the
+	// attribute value. If the value is larger than size, implementations may
+	// return ERANGE to indicate that the buffer is too small, but they are also
+	// free to ignore the hint entirely (i.e. the value returned may be larger
+	// than size). All size checking is done independently at the syscall layer.
+	//
+	// On the server, GetXattr has a read concurrency guarantee.
+	GetXattr(name string, size uint64) (string, error)
+
+	// SetXattr sets extended attributes on this node.
+	//
+	// On the server, SetXattr has a write concurrency guarantee.
+	SetXattr(name, value string, flags uint32) error
+
+	// ListXattr lists the names of the extended attributes on this node.
+	//
+	// Size indicates the size of the buffer that has been allocated to hold the
+	// attribute list. If the list would be larger than size, implementations may
+	// return ERANGE to indicate that the buffer is too small, but they are also
+	// free to ignore the hint entirely (i.e. the value returned may be larger
+	// than size). All size checking is done independently at the syscall layer.
+	//
+	// On the server, ListXattr has a read concurrency guarantee.
+	ListXattr(size uint64) (map[string]struct{}, error)
+
+	// RemoveXattr removes extended attributes on this node.
+	//
+	// On the server, RemoveXattr has a write concurrency guarantee.
+	RemoveXattr(name string) error
+
 	// Allocate allows the caller to directly manipulate the allocated disk space
 	// for the file. See fallocate(2) for more details.
 	Allocate(mode AllocateMode, offset, length uint64) error
@@ -116,7 +148,7 @@ type File interface {
 	// N.B. The server must resolve any lazy paths when open is called.
 	// After this point, read and write may be called on files with no
 	// deletion check, so resolving in the data path is not viable.
-	Open(mode OpenFlags) (*fd.FD, QID, uint32, error)
+	Open(flags OpenFlags) (*fd.FD, QID, uint32, error)
 
 	// Read reads from this file. Open must be called first.
 	//
diff --git a/pkg/p9/handlers.go b/pkg/p9/handlers.go
index ba9a55d6d..1db5797dd 100644
--- a/pkg/p9/handlers.go
+++ b/pkg/p9/handlers.go
@@ -48,6 +48,8 @@ func ExtractErrno(err error) syscall.Errno {
 		return ExtractErrno(e.Err)
 	case *os.SyscallError:
 		return ExtractErrno(e.Err)
+	case *os.LinkError:
+		return ExtractErrno(e.Err)
 	}
 
 	// Default case.
@@ -257,7 +259,6 @@ func CanOpen(mode FileMode) bool {
 
 // handle implements handler.handle.
 func (t *Tlopen) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -272,15 +273,15 @@ func (t *Tlopen) handle(cs *connState) message {
 		return newErr(syscall.EINVAL)
 	}
 
-	// Are flags valid?
-	flags := t.Flags &^ OpenFlagsIgnoreMask
-	if flags&^OpenFlagsModeMask != 0 {
-		return newErr(syscall.EINVAL)
-	}
-
-	// Is this an attempt to open a directory as writable? Don't accept.
-	if ref.mode.IsDir() && flags != ReadOnly {
-		return newErr(syscall.EINVAL)
+	if ref.mode.IsDir() {
+		// Directory must be opened ReadOnly.
+		if t.Flags&OpenFlagsModeMask != ReadOnly {
+			return newErr(syscall.EISDIR)
+		}
+		// Directory not truncatable.
+		if t.Flags&OpenTruncate != 0 {
+			return newErr(syscall.EISDIR)
+		}
 	}
 
 	var (
@@ -294,7 +295,6 @@ func (t *Tlopen) handle(cs *connState) message {
 			return syscall.EINVAL
 		}
 
-		// Do the open.
 		osFile, qid, ioUnit, err = ref.file.Open(t.Flags)
 		return err
 	}); err != nil {
@@ -311,12 +311,10 @@ func (t *Tlopen) handle(cs *connState) message {
 }
 
 func (t *Tlcreate) do(cs *connState, uid UID) (*Rlcreate, error) {
-	// Don't allow complex names.
 	if err := checkSafeName(t.Name); err != nil {
 		return nil, err
 	}
 
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return nil, syscall.EBADF
@@ -390,12 +388,10 @@ func (t *Tsymlink) handle(cs *connState) message {
 }
 
 func (t *Tsymlink) do(cs *connState, uid UID) (*Rsymlink, error) {
-	// Don't allow complex names.
 	if err := checkSafeName(t.Name); err != nil {
 		return nil, err
 	}
 
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.Directory)
 	if !ok {
 		return nil, syscall.EBADF
@@ -426,19 +422,16 @@ func (t *Tsymlink) do(cs *connState, uid UID) (*Rsymlink, error) {
 
 // handle implements handler.handle.
 func (t *Tlink) handle(cs *connState) message {
-	// Don't allow complex names.
 	if err := checkSafeName(t.Name); err != nil {
 		return newErr(err)
 	}
 
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.Directory)
 	if !ok {
 		return newErr(syscall.EBADF)
 	}
 	defer ref.DecRef()
 
-	// Lookup the other FID.
 	refTarget, ok := cs.LookupFID(t.Target)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -467,7 +460,6 @@ func (t *Tlink) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Trenameat) handle(cs *connState) message {
-	// Don't allow complex names.
 	if err := checkSafeName(t.OldName); err != nil {
 		return newErr(err)
 	}
@@ -475,14 +467,12 @@ func (t *Trenameat) handle(cs *connState) message {
 		return newErr(err)
 	}
 
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.OldDirectory)
 	if !ok {
 		return newErr(syscall.EBADF)
 	}
 	defer ref.DecRef()
 
-	// Lookup the other FID.
 	refTarget, ok := cs.LookupFID(t.NewDirectory)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -523,12 +513,10 @@ func (t *Trenameat) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Tunlinkat) handle(cs *connState) message {
-	// Don't allow complex names.
 	if err := checkSafeName(t.Name); err != nil {
 		return newErr(err)
 	}
 
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.Directory)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -577,19 +565,16 @@ func (t *Tunlinkat) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Trename) handle(cs *connState) message {
-	// Don't allow complex names.
 	if err := checkSafeName(t.Name); err != nil {
 		return newErr(err)
 	}
 
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
 	}
 	defer ref.DecRef()
 
-	// Lookup the target.
 	refTarget, ok := cs.LookupFID(t.Directory)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -641,7 +626,6 @@ func (t *Trename) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Treadlink) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -669,7 +653,6 @@ func (t *Treadlink) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Tread) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -708,7 +691,6 @@ func (t *Tread) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Twrite) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -747,12 +729,10 @@ func (t *Tmknod) handle(cs *connState) message {
 }
 
 func (t *Tmknod) do(cs *connState, uid UID) (*Rmknod, error) {
-	// Don't allow complex names.
 	if err := checkSafeName(t.Name); err != nil {
 		return nil, err
 	}
 
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.Directory)
 	if !ok {
 		return nil, syscall.EBADF
@@ -791,12 +771,10 @@ func (t *Tmkdir) handle(cs *connState) message {
 }
 
 func (t *Tmkdir) do(cs *connState, uid UID) (*Rmkdir, error) {
-	// Don't allow complex names.
 	if err := checkSafeName(t.Name); err != nil {
 		return nil, err
 	}
 
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.Directory)
 	if !ok {
 		return nil, syscall.EBADF
@@ -827,7 +805,6 @@ func (t *Tmkdir) do(cs *connState, uid UID) (*Rmkdir, error) {
 
 // handle implements handler.handle.
 func (t *Tgetattr) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -856,7 +833,6 @@ func (t *Tgetattr) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Tsetattr) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -883,7 +859,6 @@ func (t *Tsetattr) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Tallocate) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -917,7 +892,6 @@ func (t *Tallocate) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Txattrwalk) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -930,7 +904,6 @@ func (t *Txattrwalk) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Txattrcreate) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -942,8 +915,96 @@ func (t *Txattrcreate) handle(cs *connState) message {
 }
 
 // handle implements handler.handle.
+func (t *Tgetxattr) handle(cs *connState) message {
+	ref, ok := cs.LookupFID(t.FID)
+	if !ok {
+		return newErr(syscall.EBADF)
+	}
+	defer ref.DecRef()
+
+	var val string
+	if err := ref.safelyRead(func() (err error) {
+		// Don't allow getxattr on files that have been deleted.
+		if ref.isDeleted() {
+			return syscall.EINVAL
+		}
+		val, err = ref.file.GetXattr(t.Name, t.Size)
+		return err
+	}); err != nil {
+		return newErr(err)
+	}
+	return &Rgetxattr{Value: val}
+}
+
+// handle implements handler.handle.
+func (t *Tsetxattr) handle(cs *connState) message {
+	ref, ok := cs.LookupFID(t.FID)
+	if !ok {
+		return newErr(syscall.EBADF)
+	}
+	defer ref.DecRef()
+
+	if err := ref.safelyWrite(func() error {
+		// Don't allow setxattr on files that have been deleted.
+		if ref.isDeleted() {
+			return syscall.EINVAL
+		}
+		return ref.file.SetXattr(t.Name, t.Value, t.Flags)
+	}); err != nil {
+		return newErr(err)
+	}
+	return &Rsetxattr{}
+}
+
+// handle implements handler.handle.
+func (t *Tlistxattr) handle(cs *connState) message {
+	ref, ok := cs.LookupFID(t.FID)
+	if !ok {
+		return newErr(syscall.EBADF)
+	}
+	defer ref.DecRef()
+
+	var xattrs map[string]struct{}
+	if err := ref.safelyRead(func() (err error) {
+		// Don't allow listxattr on files that have been deleted.
+		if ref.isDeleted() {
+			return syscall.EINVAL
+		}
+		xattrs, err = ref.file.ListXattr(t.Size)
+		return err
+	}); err != nil {
+		return newErr(err)
+	}
+
+	xattrList := make([]string, 0, len(xattrs))
+	for x := range xattrs {
+		xattrList = append(xattrList, x)
+	}
+	return &Rlistxattr{Xattrs: xattrList}
+}
+
+// handle implements handler.handle.
+func (t *Tremovexattr) handle(cs *connState) message {
+	ref, ok := cs.LookupFID(t.FID)
+	if !ok {
+		return newErr(syscall.EBADF)
+	}
+	defer ref.DecRef()
+
+	if err := ref.safelyWrite(func() error {
+		// Don't allow removexattr on files that have been deleted.
+		if ref.isDeleted() {
+			return syscall.EINVAL
+		}
+		return ref.file.RemoveXattr(t.Name)
+	}); err != nil {
+		return newErr(err)
+	}
+	return &Rremovexattr{}
+}
+
+// handle implements handler.handle.
 func (t *Treaddir) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.Directory)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -977,7 +1038,6 @@ func (t *Treaddir) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Tfsync) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -1001,7 +1061,6 @@ func (t *Tfsync) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Tstatfs) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -1192,7 +1251,6 @@ func doWalk(cs *connState, ref *fidRef, names []string, getattr bool) (qids []QI
 
 // handle implements handler.handle.
 func (t *Twalk) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -1213,7 +1271,6 @@ func (t *Twalk) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Twalkgetattr) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -1270,7 +1327,6 @@ func (t *Tumknod) handle(cs *connState) message {
 
 // handle implements handler.handle.
 func (t *Tlconnect) handle(cs *connState) message {
-	// Lookup the FID.
 	ref, ok := cs.LookupFID(t.FID)
 	if !ok {
 		return newErr(syscall.EBADF)
@@ -1303,7 +1359,6 @@ func (t *Tchannel) handle(cs *connState) message {
 		return newErr(err)
 	}
 
-	// Lookup the given channel.
 	ch := cs.lookupChannel(t.ID)
 	if ch == nil {
 		return newErr(syscall.ENOSYS)
diff --git a/pkg/p9/messages.go b/pkg/p9/messages.go
index ffdd7e8c6..2cb59f934 100644
--- a/pkg/p9/messages.go
+++ b/pkg/p9/messages.go
@@ -51,7 +51,7 @@ type payloader interface {
 	// SetPayload returns the decoded message.
 	//
 	// This is going to be total message size - FixedSize. But this should
-	// be validated during Decode, which will be called after SetPayload.
+	// be validated during decode, which will be called after SetPayload.
 	SetPayload([]byte)
 }
 
@@ -90,14 +90,14 @@ type Tversion struct {
 	Version string
 }
 
-// Decode implements encoder.Decode.
-func (t *Tversion) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tversion) decode(b *buffer) {
 	t.MSize = b.Read32()
 	t.Version = b.ReadString()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tversion) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tversion) encode(b *buffer) {
 	b.Write32(t.MSize)
 	b.WriteString(t.Version)
 }
@@ -121,14 +121,14 @@ type Rversion struct {
 	Version string
 }
 
-// Decode implements encoder.Decode.
-func (r *Rversion) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (r *Rversion) decode(b *buffer) {
 	r.MSize = b.Read32()
 	r.Version = b.ReadString()
 }
 
-// Encode implements encoder.Encode.
-func (r *Rversion) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (r *Rversion) encode(b *buffer) {
 	b.Write32(r.MSize)
 	b.WriteString(r.Version)
 }
@@ -149,13 +149,13 @@ type Tflush struct {
 	OldTag Tag
 }
 
-// Decode implements encoder.Decode.
-func (t *Tflush) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tflush) decode(b *buffer) {
 	t.OldTag = b.ReadTag()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tflush) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tflush) encode(b *buffer) {
 	b.WriteTag(t.OldTag)
 }
 
@@ -173,12 +173,12 @@ func (t *Tflush) String() string {
 type Rflush struct {
 }
 
-// Decode implements encoder.Decode.
-func (*Rflush) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Rflush) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Rflush) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Rflush) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -188,7 +188,7 @@ func (*Rflush) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (r *Rflush) String() string {
-	return fmt.Sprintf("RFlush{}")
+	return "RFlush{}"
 }
 
 // Twalk is a walk request.
@@ -203,8 +203,8 @@ type Twalk struct {
 	Names []string
 }
 
-// Decode implements encoder.Decode.
-func (t *Twalk) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Twalk) decode(b *buffer) {
 	t.FID = b.ReadFID()
 	t.NewFID = b.ReadFID()
 	n := b.Read16()
@@ -214,8 +214,8 @@ func (t *Twalk) Decode(b *buffer) {
 	}
 }
 
-// Encode implements encoder.Encode.
-func (t *Twalk) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Twalk) encode(b *buffer) {
 	b.WriteFID(t.FID)
 	b.WriteFID(t.NewFID)
 	b.Write16(uint16(len(t.Names)))
@@ -240,22 +240,22 @@ type Rwalk struct {
 	QIDs []QID
 }
 
-// Decode implements encoder.Decode.
-func (r *Rwalk) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (r *Rwalk) decode(b *buffer) {
 	n := b.Read16()
 	r.QIDs = r.QIDs[:0]
 	for i := 0; i < int(n); i++ {
 		var q QID
-		q.Decode(b)
+		q.decode(b)
 		r.QIDs = append(r.QIDs, q)
 	}
 }
 
-// Encode implements encoder.Encode.
-func (r *Rwalk) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (r *Rwalk) encode(b *buffer) {
 	b.Write16(uint16(len(r.QIDs)))
 	for _, q := range r.QIDs {
-		q.Encode(b)
+		q.encode(b)
 	}
 }
 
@@ -275,13 +275,13 @@ type Tclunk struct {
 	FID FID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tclunk) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tclunk) decode(b *buffer) {
 	t.FID = b.ReadFID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tclunk) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tclunk) encode(b *buffer) {
 	b.WriteFID(t.FID)
 }
 
@@ -299,12 +299,12 @@ func (t *Tclunk) String() string {
 type Rclunk struct {
 }
 
-// Decode implements encoder.Decode.
-func (*Rclunk) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Rclunk) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Rclunk) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Rclunk) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -314,7 +314,7 @@ func (*Rclunk) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (r *Rclunk) String() string {
-	return fmt.Sprintf("Rclunk{}")
+	return "Rclunk{}"
 }
 
 // Tremove is a remove request.
@@ -325,13 +325,13 @@ type Tremove struct {
 	FID FID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tremove) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tremove) decode(b *buffer) {
 	t.FID = b.ReadFID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tremove) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tremove) encode(b *buffer) {
 	b.WriteFID(t.FID)
 }
 
@@ -349,12 +349,12 @@ func (t *Tremove) String() string {
 type Rremove struct {
 }
 
-// Decode implements encoder.Decode.
-func (*Rremove) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Rremove) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Rremove) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Rremove) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -364,7 +364,7 @@ func (*Rremove) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (r *Rremove) String() string {
-	return fmt.Sprintf("Rremove{}")
+	return "Rremove{}"
 }
 
 // Rlerror is an error response.
@@ -374,13 +374,13 @@ type Rlerror struct {
 	Error uint32
 }
 
-// Decode implements encoder.Decode.
-func (r *Rlerror) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (r *Rlerror) decode(b *buffer) {
 	r.Error = b.Read32()
 }
 
-// Encode implements encoder.Encode.
-func (r *Rlerror) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (r *Rlerror) encode(b *buffer) {
 	b.Write32(r.Error)
 }
 
@@ -409,16 +409,16 @@ type Tauth struct {
 	UID UID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tauth) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tauth) decode(b *buffer) {
 	t.AuthenticationFID = b.ReadFID()
 	t.UserName = b.ReadString()
 	t.AttachName = b.ReadString()
 	t.UID = b.ReadUID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tauth) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tauth) encode(b *buffer) {
 	b.WriteFID(t.AuthenticationFID)
 	b.WriteString(t.UserName)
 	b.WriteString(t.AttachName)
@@ -437,7 +437,7 @@ func (t *Tauth) String() string {
 
 // Rauth is an authentication response.
 //
-// Encode, Decode and Length are inherited directly from QID.
+// encode and decode are inherited directly from QID.
 type Rauth struct {
 	QID
 }
@@ -463,16 +463,16 @@ type Tattach struct {
 	Auth Tauth
 }
 
-// Decode implements encoder.Decode.
-func (t *Tattach) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tattach) decode(b *buffer) {
 	t.FID = b.ReadFID()
-	t.Auth.Decode(b)
+	t.Auth.decode(b)
 }
 
-// Encode implements encoder.Encode.
-func (t *Tattach) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tattach) encode(b *buffer) {
 	b.WriteFID(t.FID)
-	t.Auth.Encode(b)
+	t.Auth.encode(b)
 }
 
 // Type implements message.Type.
@@ -509,14 +509,14 @@ type Tlopen struct {
 	Flags OpenFlags
 }
 
-// Decode implements encoder.Decode.
-func (t *Tlopen) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tlopen) decode(b *buffer) {
 	t.FID = b.ReadFID()
 	t.Flags = b.ReadOpenFlags()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tlopen) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tlopen) encode(b *buffer) {
 	b.WriteFID(t.FID)
 	b.WriteOpenFlags(t.Flags)
 }
@@ -542,15 +542,15 @@ type Rlopen struct {
 	filePayload
 }
 
-// Decode implements encoder.Decode.
-func (r *Rlopen) Decode(b *buffer) {
-	r.QID.Decode(b)
+// decode implements encoder.decode.
+func (r *Rlopen) decode(b *buffer) {
+	r.QID.decode(b)
 	r.IoUnit = b.Read32()
 }
 
-// Encode implements encoder.Encode.
-func (r *Rlopen) Encode(b *buffer) {
-	r.QID.Encode(b)
+// encode implements encoder.encode.
+func (r *Rlopen) encode(b *buffer) {
+	r.QID.encode(b)
 	b.Write32(r.IoUnit)
 }
 
@@ -587,8 +587,8 @@ type Tlcreate struct {
 	GID GID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tlcreate) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tlcreate) decode(b *buffer) {
 	t.FID = b.ReadFID()
 	t.Name = b.ReadString()
 	t.OpenFlags = b.ReadOpenFlags()
@@ -596,8 +596,8 @@ func (t *Tlcreate) Decode(b *buffer) {
 	t.GID = b.ReadGID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tlcreate) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tlcreate) encode(b *buffer) {
 	b.WriteFID(t.FID)
 	b.WriteString(t.Name)
 	b.WriteOpenFlags(t.OpenFlags)
@@ -617,7 +617,7 @@ func (t *Tlcreate) String() string {
 
 // Rlcreate is a create response.
 //
-// The Encode, Decode, etc. methods are inherited from Rlopen.
+// The encode, decode, etc. methods are inherited from Rlopen.
 type Rlcreate struct {
 	Rlopen
 }
@@ -647,16 +647,16 @@ type Tsymlink struct {
 	GID GID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tsymlink) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tsymlink) decode(b *buffer) {
 	t.Directory = b.ReadFID()
 	t.Name = b.ReadString()
 	t.Target = b.ReadString()
 	t.GID = b.ReadGID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tsymlink) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tsymlink) encode(b *buffer) {
 	b.WriteFID(t.Directory)
 	b.WriteString(t.Name)
 	b.WriteString(t.Target)
@@ -679,14 +679,14 @@ type Rsymlink struct {
 	QID QID
 }
 
-// Decode implements encoder.Decode.
-func (r *Rsymlink) Decode(b *buffer) {
-	r.QID.Decode(b)
+// decode implements encoder.decode.
+func (r *Rsymlink) decode(b *buffer) {
+	r.QID.decode(b)
 }
 
-// Encode implements encoder.Encode.
-func (r *Rsymlink) Encode(b *buffer) {
-	r.QID.Encode(b)
+// encode implements encoder.encode.
+func (r *Rsymlink) encode(b *buffer) {
+	r.QID.encode(b)
 }
 
 // Type implements message.Type.
@@ -711,15 +711,15 @@ type Tlink struct {
 	Name string
 }
 
-// Decode implements encoder.Decode.
-func (t *Tlink) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tlink) decode(b *buffer) {
 	t.Directory = b.ReadFID()
 	t.Target = b.ReadFID()
 	t.Name = b.ReadString()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tlink) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tlink) encode(b *buffer) {
 	b.WriteFID(t.Directory)
 	b.WriteFID(t.Target)
 	b.WriteString(t.Name)
@@ -744,17 +744,17 @@ func (*Rlink) Type() MsgType {
 	return MsgRlink
 }
 
-// Decode implements encoder.Decode.
-func (*Rlink) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Rlink) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Rlink) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Rlink) encode(*buffer) {
 }
 
 // String implements fmt.Stringer.
 func (r *Rlink) String() string {
-	return fmt.Sprintf("Rlink{}")
+	return "Rlink{}"
 }
 
 // Trenameat is a rename request.
@@ -772,16 +772,16 @@ type Trenameat struct {
 	NewName string
 }
 
-// Decode implements encoder.Decode.
-func (t *Trenameat) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Trenameat) decode(b *buffer) {
 	t.OldDirectory = b.ReadFID()
 	t.OldName = b.ReadString()
 	t.NewDirectory = b.ReadFID()
 	t.NewName = b.ReadString()
 }
 
-// Encode implements encoder.Encode.
-func (t *Trenameat) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Trenameat) encode(b *buffer) {
 	b.WriteFID(t.OldDirectory)
 	b.WriteString(t.OldName)
 	b.WriteFID(t.NewDirectory)
@@ -802,12 +802,12 @@ func (t *Trenameat) String() string {
 type Rrenameat struct {
 }
 
-// Decode implements encoder.Decode.
-func (*Rrenameat) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Rrenameat) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Rrenameat) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Rrenameat) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -817,7 +817,7 @@ func (*Rrenameat) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (r *Rrenameat) String() string {
-	return fmt.Sprintf("Rrenameat{}")
+	return "Rrenameat{}"
 }
 
 // Tunlinkat is an unlink request.
@@ -832,15 +832,15 @@ type Tunlinkat struct {
 	Flags uint32
 }
 
-// Decode implements encoder.Decode.
-func (t *Tunlinkat) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tunlinkat) decode(b *buffer) {
 	t.Directory = b.ReadFID()
 	t.Name = b.ReadString()
 	t.Flags = b.Read32()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tunlinkat) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tunlinkat) encode(b *buffer) {
 	b.WriteFID(t.Directory)
 	b.WriteString(t.Name)
 	b.Write32(t.Flags)
@@ -860,12 +860,12 @@ func (t *Tunlinkat) String() string {
 type Runlinkat struct {
 }
 
-// Decode implements encoder.Decode.
-func (*Runlinkat) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Runlinkat) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Runlinkat) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Runlinkat) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -875,7 +875,7 @@ func (*Runlinkat) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (r *Runlinkat) String() string {
-	return fmt.Sprintf("Runlinkat{}")
+	return "Runlinkat{}"
 }
 
 // Trename is a rename request.
@@ -893,15 +893,15 @@ type Trename struct {
 	Name string
 }
 
-// Decode implements encoder.Decode.
-func (t *Trename) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Trename) decode(b *buffer) {
 	t.FID = b.ReadFID()
 	t.Directory = b.ReadFID()
 	t.Name = b.ReadString()
 }
 
-// Encode implements encoder.Encode.
-func (t *Trename) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Trename) encode(b *buffer) {
 	b.WriteFID(t.FID)
 	b.WriteFID(t.Directory)
 	b.WriteString(t.Name)
@@ -921,12 +921,12 @@ func (t *Trename) String() string {
 type Rrename struct {
 }
 
-// Decode implements encoder.Decode.
-func (*Rrename) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Rrename) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Rrename) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Rrename) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -936,7 +936,7 @@ func (*Rrename) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (r *Rrename) String() string {
-	return fmt.Sprintf("Rrename{}")
+	return "Rrename{}"
 }
 
 // Treadlink is a readlink request.
@@ -945,13 +945,13 @@ type Treadlink struct {
 	FID FID
 }
 
-// Decode implements encoder.Decode.
-func (t *Treadlink) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Treadlink) decode(b *buffer) {
 	t.FID = b.ReadFID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Treadlink) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Treadlink) encode(b *buffer) {
 	b.WriteFID(t.FID)
 }
 
@@ -971,13 +971,13 @@ type Rreadlink struct {
 	Target string
 }
 
-// Decode implements encoder.Decode.
-func (r *Rreadlink) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (r *Rreadlink) decode(b *buffer) {
 	r.Target = b.ReadString()
 }
 
-// Encode implements encoder.Encode.
-func (r *Rreadlink) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (r *Rreadlink) encode(b *buffer) {
 	b.WriteString(r.Target)
 }
 
@@ -1003,15 +1003,15 @@ type Tread struct {
 	Count uint32
 }
 
-// Decode implements encoder.Decode.
-func (t *Tread) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tread) decode(b *buffer) {
 	t.FID = b.ReadFID()
 	t.Offset = b.Read64()
 	t.Count = b.Read32()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tread) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tread) encode(b *buffer) {
 	b.WriteFID(t.FID)
 	b.Write64(t.Offset)
 	b.Write32(t.Count)
@@ -1033,20 +1033,20 @@ type Rread struct {
 	Data []byte
 }
 
-// Decode implements encoder.Decode.
+// decode implements encoder.decode.
 //
 // Data is automatically decoded via Payload.
-func (r *Rread) Decode(b *buffer) {
+func (r *Rread) decode(b *buffer) {
 	count := b.Read32()
 	if count != uint32(len(r.Data)) {
 		b.markOverrun()
 	}
 }
 
-// Encode implements encoder.Encode.
+// encode implements encoder.encode.
 //
 // Data is automatically encoded via Payload.
-func (r *Rread) Encode(b *buffer) {
+func (r *Rread) encode(b *buffer) {
 	b.Write32(uint32(len(r.Data)))
 }
 
@@ -1087,8 +1087,8 @@ type Twrite struct {
 	Data []byte
 }
 
-// Decode implements encoder.Decode.
-func (t *Twrite) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Twrite) decode(b *buffer) {
 	t.FID = b.ReadFID()
 	t.Offset = b.Read64()
 	count := b.Read32()
@@ -1097,10 +1097,10 @@ func (t *Twrite) Decode(b *buffer) {
 	}
 }
 
-// Encode implements encoder.Encode.
+// encode implements encoder.encode.
 //
 // This uses the buffer payload to avoid a copy.
-func (t *Twrite) Encode(b *buffer) {
+func (t *Twrite) encode(b *buffer) {
 	b.WriteFID(t.FID)
 	b.Write64(t.Offset)
 	b.Write32(uint32(len(t.Data)))
@@ -1137,13 +1137,13 @@ type Rwrite struct {
 	Count uint32
 }
 
-// Decode implements encoder.Decode.
-func (r *Rwrite) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (r *Rwrite) decode(b *buffer) {
 	r.Count = b.Read32()
 }
 
-// Encode implements encoder.Encode.
-func (r *Rwrite) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (r *Rwrite) encode(b *buffer) {
 	b.Write32(r.Count)
 }
 
@@ -1178,8 +1178,8 @@ type Tmknod struct {
 	GID GID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tmknod) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tmknod) decode(b *buffer) {
 	t.Directory = b.ReadFID()
 	t.Name = b.ReadString()
 	t.Mode = b.ReadFileMode()
@@ -1188,8 +1188,8 @@ func (t *Tmknod) Decode(b *buffer) {
 	t.GID = b.ReadGID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tmknod) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tmknod) encode(b *buffer) {
 	b.WriteFID(t.Directory)
 	b.WriteString(t.Name)
 	b.WriteFileMode(t.Mode)
@@ -1214,14 +1214,14 @@ type Rmknod struct {
 	QID QID
 }
 
-// Decode implements encoder.Decode.
-func (r *Rmknod) Decode(b *buffer) {
-	r.QID.Decode(b)
+// decode implements encoder.decode.
+func (r *Rmknod) decode(b *buffer) {
+	r.QID.decode(b)
 }
 
-// Encode implements encoder.Encode.
-func (r *Rmknod) Encode(b *buffer) {
-	r.QID.Encode(b)
+// encode implements encoder.encode.
+func (r *Rmknod) encode(b *buffer) {
+	r.QID.encode(b)
 }
 
 // Type implements message.Type.
@@ -1249,16 +1249,16 @@ type Tmkdir struct {
 	GID GID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tmkdir) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tmkdir) decode(b *buffer) {
 	t.Directory = b.ReadFID()
 	t.Name = b.ReadString()
 	t.Permissions = b.ReadPermissions()
 	t.GID = b.ReadGID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tmkdir) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tmkdir) encode(b *buffer) {
 	b.WriteFID(t.Directory)
 	b.WriteString(t.Name)
 	b.WritePermissions(t.Permissions)
@@ -1281,14 +1281,14 @@ type Rmkdir struct {
 	QID QID
 }
 
-// Decode implements encoder.Decode.
-func (r *Rmkdir) Decode(b *buffer) {
-	r.QID.Decode(b)
+// decode implements encoder.decode.
+func (r *Rmkdir) decode(b *buffer) {
+	r.QID.decode(b)
 }
 
-// Encode implements encoder.Encode.
-func (r *Rmkdir) Encode(b *buffer) {
-	r.QID.Encode(b)
+// encode implements encoder.encode.
+func (r *Rmkdir) encode(b *buffer) {
+	r.QID.encode(b)
 }
 
 // Type implements message.Type.
@@ -1310,16 +1310,16 @@ type Tgetattr struct {
 	AttrMask AttrMask
 }
 
-// Decode implements encoder.Decode.
-func (t *Tgetattr) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tgetattr) decode(b *buffer) {
 	t.FID = b.ReadFID()
-	t.AttrMask.Decode(b)
+	t.AttrMask.decode(b)
 }
 
-// Encode implements encoder.Encode.
-func (t *Tgetattr) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tgetattr) encode(b *buffer) {
 	b.WriteFID(t.FID)
-	t.AttrMask.Encode(b)
+	t.AttrMask.encode(b)
 }
 
 // Type implements message.Type.
@@ -1344,18 +1344,18 @@ type Rgetattr struct {
 	Attr Attr
 }
 
-// Decode implements encoder.Decode.
-func (r *Rgetattr) Decode(b *buffer) {
-	r.Valid.Decode(b)
-	r.QID.Decode(b)
-	r.Attr.Decode(b)
+// decode implements encoder.decode.
+func (r *Rgetattr) decode(b *buffer) {
+	r.Valid.decode(b)
+	r.QID.decode(b)
+	r.Attr.decode(b)
 }
 
-// Encode implements encoder.Encode.
-func (r *Rgetattr) Encode(b *buffer) {
-	r.Valid.Encode(b)
-	r.QID.Encode(b)
-	r.Attr.Encode(b)
+// encode implements encoder.encode.
+func (r *Rgetattr) encode(b *buffer) {
+	r.Valid.encode(b)
+	r.QID.encode(b)
+	r.Attr.encode(b)
 }
 
 // Type implements message.Type.
@@ -1380,18 +1380,18 @@ type Tsetattr struct {
 	SetAttr SetAttr
 }
 
-// Decode implements encoder.Decode.
-func (t *Tsetattr) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tsetattr) decode(b *buffer) {
 	t.FID = b.ReadFID()
-	t.Valid.Decode(b)
-	t.SetAttr.Decode(b)
+	t.Valid.decode(b)
+	t.SetAttr.decode(b)
 }
 
-// Encode implements encoder.Encode.
-func (t *Tsetattr) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tsetattr) encode(b *buffer) {
 	b.WriteFID(t.FID)
-	t.Valid.Encode(b)
-	t.SetAttr.Encode(b)
+	t.Valid.encode(b)
+	t.SetAttr.encode(b)
 }
 
 // Type implements message.Type.
@@ -1408,12 +1408,12 @@ func (t *Tsetattr) String() string {
 type Rsetattr struct {
 }
 
-// Decode implements encoder.Decode.
-func (*Rsetattr) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Rsetattr) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Rsetattr) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Rsetattr) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -1423,7 +1423,7 @@ func (*Rsetattr) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (r *Rsetattr) String() string {
-	return fmt.Sprintf("Rsetattr{}")
+	return "Rsetattr{}"
 }
 
 // Tallocate is an allocate request. This is an extension to 9P protocol, not
@@ -1435,18 +1435,18 @@ type Tallocate struct {
 	Length uint64
 }
 
-// Decode implements encoder.Decode.
-func (t *Tallocate) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tallocate) decode(b *buffer) {
 	t.FID = b.ReadFID()
-	t.Mode.Decode(b)
+	t.Mode.decode(b)
 	t.Offset = b.Read64()
 	t.Length = b.Read64()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tallocate) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tallocate) encode(b *buffer) {
 	b.WriteFID(t.FID)
-	t.Mode.Encode(b)
+	t.Mode.encode(b)
 	b.Write64(t.Offset)
 	b.Write64(t.Length)
 }
@@ -1465,12 +1465,12 @@ func (t *Tallocate) String() string {
 type Rallocate struct {
 }
 
-// Decode implements encoder.Decode.
-func (*Rallocate) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Rallocate) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Rallocate) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Rallocate) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -1480,7 +1480,71 @@ func (*Rallocate) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (r *Rallocate) String() string {
-	return fmt.Sprintf("Rallocate{}")
+	return "Rallocate{}"
+}
+
+// Tlistxattr is a listxattr request.
+type Tlistxattr struct {
+	// FID refers to the file on which to list xattrs.
+	FID FID
+
+	// Size is the buffer size for the xattr list.
+	Size uint64
+}
+
+// decode implements encoder.decode.
+func (t *Tlistxattr) decode(b *buffer) {
+	t.FID = b.ReadFID()
+	t.Size = b.Read64()
+}
+
+// encode implements encoder.encode.
+func (t *Tlistxattr) encode(b *buffer) {
+	b.WriteFID(t.FID)
+	b.Write64(t.Size)
+}
+
+// Type implements message.Type.
+func (*Tlistxattr) Type() MsgType {
+	return MsgTlistxattr
+}
+
+// String implements fmt.Stringer.
+func (t *Tlistxattr) String() string {
+	return fmt.Sprintf("Tlistxattr{FID: %d, Size: %d}", t.FID, t.Size)
+}
+
+// Rlistxattr is a listxattr response.
+type Rlistxattr struct {
+	// Xattrs is a list of extended attribute names.
+	Xattrs []string
+}
+
+// decode implements encoder.decode.
+func (r *Rlistxattr) decode(b *buffer) {
+	n := b.Read16()
+	r.Xattrs = r.Xattrs[:0]
+	for i := 0; i < int(n); i++ {
+		r.Xattrs = append(r.Xattrs, b.ReadString())
+	}
+}
+
+// encode implements encoder.encode.
+func (r *Rlistxattr) encode(b *buffer) {
+	b.Write16(uint16(len(r.Xattrs)))
+	for _, x := range r.Xattrs {
+		b.WriteString(x)
+	}
+}
+
+// Type implements message.Type.
+func (*Rlistxattr) Type() MsgType {
+	return MsgRlistxattr
+}
+
+// String implements fmt.Stringer.
+func (r *Rlistxattr) String() string {
+	return fmt.Sprintf("Rlistxattr{Xattrs: %v}", r.Xattrs)
 }
 
 // Txattrwalk walks extended attributes.
@@ -1495,15 +1559,15 @@ type Txattrwalk struct {
 	Name string
 }
 
-// Decode implements encoder.Decode.
-func (t *Txattrwalk) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Txattrwalk) decode(b *buffer) {
 	t.FID = b.ReadFID()
 	t.NewFID = b.ReadFID()
 	t.Name = b.ReadString()
 }
 
-// Encode implements encoder.Encode.
-func (t *Txattrwalk) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Txattrwalk) encode(b *buffer) {
 	b.WriteFID(t.FID)
 	b.WriteFID(t.NewFID)
 	b.WriteString(t.Name)
@@ -1525,13 +1589,13 @@ type Rxattrwalk struct {
 	Size uint64
 }
 
-// Decode implements encoder.Decode.
-func (r *Rxattrwalk) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (r *Rxattrwalk) decode(b *buffer) {
 	r.Size = b.Read64()
 }
 
-// Encode implements encoder.Encode.
-func (r *Rxattrwalk) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (r *Rxattrwalk) encode(b *buffer) {
 	b.Write64(r.Size)
 }
 
@@ -1563,16 +1627,16 @@ type Txattrcreate struct {
 	Flags uint32
 }
 
-// Decode implements encoder.Decode.
-func (t *Txattrcreate) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Txattrcreate) decode(b *buffer) {
 	t.FID = b.ReadFID()
 	t.Name = b.ReadString()
 	t.AttrSize = b.Read64()
 	t.Flags = b.Read32()
 }
 
-// Encode implements encoder.Encode.
-func (t *Txattrcreate) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Txattrcreate) encode(b *buffer) {
 	b.WriteFID(t.FID)
 	b.WriteString(t.Name)
 	b.Write64(t.AttrSize)
@@ -1593,12 +1657,12 @@ func (t *Txattrcreate) String() string {
 type Rxattrcreate struct {
 }
 
-// Decode implements encoder.Decode.
-func (r *Rxattrcreate) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (r *Rxattrcreate) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (r *Rxattrcreate) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (r *Rxattrcreate) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -1608,7 +1672,185 @@ func (*Rxattrcreate) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (r *Rxattrcreate) String() string {
-	return fmt.Sprintf("Rxattrcreate{}")
+	return "Rxattrcreate{}"
+}
+
+// Tgetxattr is a getxattr request.
+type Tgetxattr struct {
+	// FID refers to the file for which to get xattrs.
+	FID FID
+
+	// Name is the xattr to get.
+	Name string
+
+	// Size is the buffer size for the xattr to get.
+	Size uint64
+}
+
+// decode implements encoder.decode.
+func (t *Tgetxattr) decode(b *buffer) {
+	t.FID = b.ReadFID()
+	t.Name = b.ReadString()
+	t.Size = b.Read64()
+}
+
+// encode implements encoder.encode.
+func (t *Tgetxattr) encode(b *buffer) {
+	b.WriteFID(t.FID)
+	b.WriteString(t.Name)
+	b.Write64(t.Size)
+}
+
+// Type implements message.Type.
+func (*Tgetxattr) Type() MsgType {
+	return MsgTgetxattr
+}
+
+// String implements fmt.Stringer.
+func (t *Tgetxattr) String() string {
+	return fmt.Sprintf("Tgetxattr{FID: %d, Name: %s, Size: %d}", t.FID, t.Name, t.Size)
+}
+
+// Rgetxattr is a getxattr response.
+type Rgetxattr struct {
+	// Value is the extended attribute value.
+	Value string
+}
+
+// decode implements encoder.decode.
+func (r *Rgetxattr) decode(b *buffer) {
+	r.Value = b.ReadString()
+}
+
+// encode implements encoder.encode.
+func (r *Rgetxattr) encode(b *buffer) {
+	b.WriteString(r.Value)
+}
+
+// Type implements message.Type.
+func (*Rgetxattr) Type() MsgType {
+	return MsgRgetxattr
+}
+
+// String implements fmt.Stringer.
+func (r *Rgetxattr) String() string {
+	return fmt.Sprintf("Rgetxattr{Value: %s}", r.Value)
+}
+
+// Tsetxattr sets extended attributes.
+type Tsetxattr struct {
+	// FID refers to the file on which to set xattrs.
+	FID FID
+
+	// Name is the attribute name.
+	Name string
+
+	// Value is the attribute value.
+	Value string
+
+	// Linux setxattr(2) flags.
+	Flags uint32
+}
+
+// decode implements encoder.decode.
+func (t *Tsetxattr) decode(b *buffer) {
+	t.FID = b.ReadFID()
+	t.Name = b.ReadString()
+	t.Value = b.ReadString()
+	t.Flags = b.Read32()
+}
+
+// encode implements encoder.encode.
+func (t *Tsetxattr) encode(b *buffer) {
+	b.WriteFID(t.FID)
+	b.WriteString(t.Name)
+	b.WriteString(t.Value)
+	b.Write32(t.Flags)
+}
+
+// Type implements message.Type.
+func (*Tsetxattr) Type() MsgType {
+	return MsgTsetxattr
+}
+
+// String implements fmt.Stringer.
+func (t *Tsetxattr) String() string {
+	return fmt.Sprintf("Tsetxattr{FID: %d, Name: %s, Value: %s, Flags: %d}", t.FID, t.Name, t.Value, t.Flags)
+}
+
+// Rsetxattr is a setxattr response.
+type Rsetxattr struct {
+}
+
+// decode implements encoder.decode.
+func (r *Rsetxattr) decode(*buffer) {
+}
+
+// encode implements encoder.encode.
+func (r *Rsetxattr) encode(*buffer) {
+}
+
+// Type implements message.Type.
+func (*Rsetxattr) Type() MsgType {
+	return MsgRsetxattr
+}
+
+// String implements fmt.Stringer.
+func (r *Rsetxattr) String() string {
+	return "Rsetxattr{}"
+}
+
+// Tremovexattr is a removexattr request.
+type Tremovexattr struct {
+	// FID refers to the file on which to set xattrs.
+	FID FID
+
+	// Name is the attribute name.
+	Name string
+}
+
+// decode implements encoder.decode.
+func (t *Tremovexattr) decode(b *buffer) {
+	t.FID = b.ReadFID()
+	t.Name = b.ReadString()
+}
+
+// encode implements encoder.encode.
+func (t *Tremovexattr) encode(b *buffer) {
+	b.WriteFID(t.FID)
+	b.WriteString(t.Name)
+}
+
+// Type implements message.Type.
+func (*Tremovexattr) Type() MsgType {
+	return MsgTremovexattr
+}
+
+// String implements fmt.Stringer.
+func (t *Tremovexattr) String() string {
+	return fmt.Sprintf("Tremovexattr{FID: %d, Name: %s}", t.FID, t.Name)
+}
+
+// Rremovexattr is a removexattr response.
+type Rremovexattr struct {
+}
+
+// decode implements encoder.decode.
+func (r *Rremovexattr) decode(*buffer) {
+}
+
+// encode implements encoder.encode.
+func (r *Rremovexattr) encode(*buffer) {
+}
+
+// Type implements message.Type.
+func (*Rremovexattr) Type() MsgType {
+	return MsgRremovexattr
+}
+
+// String implements fmt.Stringer.
+func (r *Rremovexattr) String() string {
+	return "Rremovexattr{}"
 }
 
 // Treaddir is a readdir request.
@@ -1623,15 +1865,15 @@ type Treaddir struct {
 	Count uint32
 }
 
-// Decode implements encoder.Decode.
-func (t *Treaddir) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Treaddir) decode(b *buffer) {
 	t.Directory = b.ReadFID()
 	t.Offset = b.Read64()
 	t.Count = b.Read32()
 }
 
-// Encode implements encoder.Encode.
-func (t *Treaddir) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Treaddir) encode(b *buffer) {
 	b.WriteFID(t.Directory)
 	b.Write64(t.Offset)
 	b.Write32(t.Count)
@@ -1665,14 +1907,14 @@ type Rreaddir struct {
 	payload []byte
 }
 
-// Decode implements encoder.Decode.
-func (r *Rreaddir) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (r *Rreaddir) decode(b *buffer) {
 	r.Count = b.Read32()
 	entriesBuf := buffer{data: r.payload}
 	r.Entries = r.Entries[:0]
 	for {
 		var d Dirent
-		d.Decode(&entriesBuf)
+		d.decode(&entriesBuf)
 		if entriesBuf.isOverrun() {
 			// Couldn't decode a complete entry.
 			break
@@ -1681,22 +1923,20 @@ func (r *Rreaddir) Decode(b *buffer) {
 	}
 }
 
-// Encode implements encoder.Encode.
-func (r *Rreaddir) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (r *Rreaddir) encode(b *buffer) {
 	entriesBuf := buffer{}
+	payloadSize := 0
 	for _, d := range r.Entries {
-		d.Encode(&entriesBuf)
-		if len(entriesBuf.data) >= int(r.Count) {
+		d.encode(&entriesBuf)
+		if len(entriesBuf.data) > int(r.Count) {
 			break
 		}
+		payloadSize = len(entriesBuf.data)
 	}
-	if len(entriesBuf.data) < int(r.Count) {
-		r.Count = uint32(len(entriesBuf.data))
-		r.payload = entriesBuf.data
-	} else {
-		r.payload = entriesBuf.data[:r.Count]
-	}
-	b.Write32(uint32(r.Count))
+	r.Count = uint32(payloadSize)
+	r.payload = entriesBuf.data[:payloadSize]
+	b.Write32(r.Count)
 }
 
 // Type implements message.Type.
@@ -1730,13 +1970,13 @@ type Tfsync struct {
 	FID FID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tfsync) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tfsync) decode(b *buffer) {
 	t.FID = b.ReadFID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tfsync) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tfsync) encode(b *buffer) {
 	b.WriteFID(t.FID)
 }
 
@@ -1754,12 +1994,12 @@ func (t *Tfsync) String() string {
 type Rfsync struct {
 }
 
-// Decode implements encoder.Decode.
-func (*Rfsync) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Rfsync) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Rfsync) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Rfsync) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -1769,7 +2009,7 @@ func (*Rfsync) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (r *Rfsync) String() string {
-	return fmt.Sprintf("Rfsync{}")
+	return "Rfsync{}"
 }
 
 // Tstatfs is a stat request.
@@ -1778,13 +2018,13 @@ type Tstatfs struct {
 	FID FID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tstatfs) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tstatfs) decode(b *buffer) {
 	t.FID = b.ReadFID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tstatfs) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tstatfs) encode(b *buffer) {
 	b.WriteFID(t.FID)
 }
 
@@ -1804,14 +2044,14 @@ type Rstatfs struct {
 	FSStat FSStat
 }
 
-// Decode implements encoder.Decode.
-func (r *Rstatfs) Decode(b *buffer) {
-	r.FSStat.Decode(b)
+// decode implements encoder.decode.
+func (r *Rstatfs) decode(b *buffer) {
+	r.FSStat.decode(b)
 }
 
-// Encode implements encoder.Encode.
-func (r *Rstatfs) Encode(b *buffer) {
-	r.FSStat.Encode(b)
+// encode implements encoder.encode.
+func (r *Rstatfs) encode(b *buffer) {
+	r.FSStat.encode(b)
 }
 
 // Type implements message.Type.
@@ -1830,13 +2070,13 @@ type Tflushf struct {
 	FID FID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tflushf) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tflushf) decode(b *buffer) {
 	t.FID = b.ReadFID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tflushf) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tflushf) encode(b *buffer) {
 	b.WriteFID(t.FID)
 }
 
@@ -1854,12 +2094,12 @@ func (t *Tflushf) String() string {
 type Rflushf struct {
 }
 
-// Decode implements encoder.Decode.
-func (*Rflushf) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (*Rflushf) decode(*buffer) {
 }
 
-// Encode implements encoder.Encode.
-func (*Rflushf) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (*Rflushf) encode(*buffer) {
 }
 
 // Type implements message.Type.
@@ -1869,7 +2109,7 @@ func (*Rflushf) Type() MsgType {
 
 // String implements fmt.Stringer.
 func (*Rflushf) String() string {
-	return fmt.Sprintf("Rflushf{}")
+	return "Rflushf{}"
 }
 
 // Twalkgetattr is a walk request.
@@ -1884,8 +2124,8 @@ type Twalkgetattr struct {
 	Names []string
 }
 
-// Decode implements encoder.Decode.
-func (t *Twalkgetattr) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Twalkgetattr) decode(b *buffer) {
 	t.FID = b.ReadFID()
 	t.NewFID = b.ReadFID()
 	n := b.Read16()
@@ -1895,8 +2135,8 @@ func (t *Twalkgetattr) Decode(b *buffer) {
 	}
 }
 
-// Encode implements encoder.Encode.
-func (t *Twalkgetattr) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Twalkgetattr) encode(b *buffer) {
 	b.WriteFID(t.FID)
 	b.WriteFID(t.NewFID)
 	b.Write16(uint16(len(t.Names)))
@@ -1927,26 +2167,26 @@ type Rwalkgetattr struct {
 	QIDs []QID
 }
 
-// Decode implements encoder.Decode.
-func (r *Rwalkgetattr) Decode(b *buffer) {
-	r.Valid.Decode(b)
-	r.Attr.Decode(b)
+// decode implements encoder.decode.
+func (r *Rwalkgetattr) decode(b *buffer) {
+	r.Valid.decode(b)
+	r.Attr.decode(b)
 	n := b.Read16()
 	r.QIDs = r.QIDs[:0]
 	for i := 0; i < int(n); i++ {
 		var q QID
-		q.Decode(b)
+		q.decode(b)
 		r.QIDs = append(r.QIDs, q)
 	}
 }
 
-// Encode implements encoder.Encode.
-func (r *Rwalkgetattr) Encode(b *buffer) {
-	r.Valid.Encode(b)
-	r.Attr.Encode(b)
+// encode implements encoder.encode.
+func (r *Rwalkgetattr) encode(b *buffer) {
+	r.Valid.encode(b)
+	r.Attr.encode(b)
 	b.Write16(uint16(len(r.QIDs)))
 	for _, q := range r.QIDs {
-		q.Encode(b)
+		q.encode(b)
 	}
 }
 
@@ -1968,15 +2208,15 @@ type Tucreate struct {
 	UID UID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tucreate) Decode(b *buffer) {
-	t.Tlcreate.Decode(b)
+// decode implements encoder.decode.
+func (t *Tucreate) decode(b *buffer) {
+	t.Tlcreate.decode(b)
 	t.UID = b.ReadUID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tucreate) Encode(b *buffer) {
-	t.Tlcreate.Encode(b)
+// encode implements encoder.encode.
+func (t *Tucreate) encode(b *buffer) {
+	t.Tlcreate.encode(b)
 	b.WriteUID(t.UID)
 }
 
@@ -2013,15 +2253,15 @@ type Tumkdir struct {
 	UID UID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tumkdir) Decode(b *buffer) {
-	t.Tmkdir.Decode(b)
+// decode implements encoder.decode.
+func (t *Tumkdir) decode(b *buffer) {
+	t.Tmkdir.decode(b)
 	t.UID = b.ReadUID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tumkdir) Encode(b *buffer) {
-	t.Tmkdir.Encode(b)
+// encode implements encoder.encode.
+func (t *Tumkdir) encode(b *buffer) {
+	t.Tmkdir.encode(b)
 	b.WriteUID(t.UID)
 }
 
@@ -2058,15 +2298,15 @@ type Tumknod struct {
 	UID UID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tumknod) Decode(b *buffer) {
-	t.Tmknod.Decode(b)
+// decode implements encoder.decode.
+func (t *Tumknod) decode(b *buffer) {
+	t.Tmknod.decode(b)
 	t.UID = b.ReadUID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tumknod) Encode(b *buffer) {
-	t.Tmknod.Encode(b)
+// encode implements encoder.encode.
+func (t *Tumknod) encode(b *buffer) {
+	t.Tmknod.encode(b)
 	b.WriteUID(t.UID)
 }
 
@@ -2103,15 +2343,15 @@ type Tusymlink struct {
 	UID UID
 }
 
-// Decode implements encoder.Decode.
-func (t *Tusymlink) Decode(b *buffer) {
-	t.Tsymlink.Decode(b)
+// decode implements encoder.decode.
+func (t *Tusymlink) decode(b *buffer) {
+	t.Tsymlink.decode(b)
 	t.UID = b.ReadUID()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tusymlink) Encode(b *buffer) {
-	t.Tsymlink.Encode(b)
+// encode implements encoder.encode.
+func (t *Tusymlink) encode(b *buffer) {
+	t.Tsymlink.encode(b)
 	b.WriteUID(t.UID)
 }
 
@@ -2149,14 +2389,14 @@ type Tlconnect struct {
 	Flags ConnectFlags
 }
 
-// Decode implements encoder.Decode.
-func (t *Tlconnect) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tlconnect) decode(b *buffer) {
 	t.FID = b.ReadFID()
 	t.Flags = b.ReadConnectFlags()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tlconnect) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tlconnect) encode(b *buffer) {
 	b.WriteFID(t.FID)
 	b.WriteConnectFlags(t.Flags)
 }
@@ -2176,11 +2416,11 @@ type Rlconnect struct {
 	filePayload
 }
 
-// Decode implements encoder.Decode.
-func (r *Rlconnect) Decode(*buffer) {}
+// decode implements encoder.decode.
+func (r *Rlconnect) decode(*buffer) {}
 
-// Encode implements encoder.Encode.
-func (r *Rlconnect) Encode(*buffer) {}
+// encode implements encoder.encode.
+func (r *Rlconnect) encode(*buffer) {}
 
 // Type implements message.Type.
 func (*Rlconnect) Type() MsgType {
@@ -2203,14 +2443,14 @@ type Tchannel struct {
 	Control uint32
 }
 
-// Decode implements encoder.Decode.
-func (t *Tchannel) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (t *Tchannel) decode(b *buffer) {
 	t.ID = b.Read32()
 	t.Control = b.Read32()
 }
 
-// Encode implements encoder.Encode.
-func (t *Tchannel) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (t *Tchannel) encode(b *buffer) {
 	b.Write32(t.ID)
 	b.Write32(t.Control)
 }
@@ -2232,14 +2472,14 @@ type Rchannel struct {
 	filePayload
 }
 
-// Decode implements encoder.Decode.
-func (r *Rchannel) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (r *Rchannel) decode(b *buffer) {
 	r.Offset = b.Read64()
 	r.Length = b.Read64()
 }
 
-// Encode implements encoder.Encode.
-func (r *Rchannel) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (r *Rchannel) encode(b *buffer) {
 	b.Write64(r.Offset)
 	b.Write64(r.Length)
 }
@@ -2266,7 +2506,7 @@ type msgFactory struct {
 var msgRegistry registry
 
 type registry struct {
-	factories [math.MaxUint8]msgFactory
+	factories [math.MaxUint8 + 1]msgFactory
 
 	// largestFixedSize is computed so that given some message size M, you can
 	// compute the maximum payload size (e.g. for Twrite, Rread) with
@@ -2335,7 +2575,7 @@ func calculateSize(m message) uint32 {
 		return p.FixedSize()
 	}
 	var dataBuf buffer
-	m.Encode(&dataBuf)
+	m.encode(&dataBuf)
 	return uint32(len(dataBuf.data))
 }
 
@@ -2359,10 +2599,18 @@ func init() {
 	msgRegistry.register(MsgRgetattr, func() message { return &Rgetattr{} })
 	msgRegistry.register(MsgTsetattr, func() message { return &Tsetattr{} })
 	msgRegistry.register(MsgRsetattr, func() message { return &Rsetattr{} })
+	msgRegistry.register(MsgTlistxattr, func() message { return &Tlistxattr{} })
+	msgRegistry.register(MsgRlistxattr, func() message { return &Rlistxattr{} })
 	msgRegistry.register(MsgTxattrwalk, func() message { return &Txattrwalk{} })
 	msgRegistry.register(MsgRxattrwalk, func() message { return &Rxattrwalk{} })
 	msgRegistry.register(MsgTxattrcreate, func() message { return &Txattrcreate{} })
 	msgRegistry.register(MsgRxattrcreate, func() message { return &Rxattrcreate{} })
+	msgRegistry.register(MsgTgetxattr, func() message { return &Tgetxattr{} })
+	msgRegistry.register(MsgRgetxattr, func() message { return &Rgetxattr{} })
+	msgRegistry.register(MsgTsetxattr, func() message { return &Tsetxattr{} })
+	msgRegistry.register(MsgRsetxattr, func() message { return &Rsetxattr{} })
+	msgRegistry.register(MsgTremovexattr, func() message { return &Tremovexattr{} })
+	msgRegistry.register(MsgRremovexattr, func() message { return &Rremovexattr{} })
 	msgRegistry.register(MsgTreaddir, func() message { return &Treaddir{} })
 	msgRegistry.register(MsgRreaddir, func() message { return &Rreaddir{} })
 	msgRegistry.register(MsgTfsync, func() message { return &Tfsync{} })
diff --git a/pkg/p9/messages_test.go b/pkg/p9/messages_test.go
index 6ba6a1654..7facc9f5e 100644
--- a/pkg/p9/messages_test.go
+++ b/pkg/p9/messages_test.go
@@ -194,6 +194,21 @@ func TestEncodeDecode(t *testing.T) {
 			Flags:    3,
 		},
 		&Rxattrcreate{},
+		&Tgetxattr{
+			FID:  1,
+			Name: "abc",
+			Size: 2,
+		},
+		&Rgetxattr{
+			Value: "xyz",
+		},
+		&Tsetxattr{
+			FID:   1,
+			Name:  "abc",
+			Value: "xyz",
+			Flags: 2,
+		},
+		&Rsetxattr{},
 		&Treaddir{
 			Directory: 1,
 			Offset:    2,
@@ -201,7 +216,7 @@ func TestEncodeDecode(t *testing.T) {
 		},
 		&Rreaddir{
 			// Count must be sufficient to encode a dirent.
-			Count:   0x18,
+			Count:   0x1a,
 			Entries: []Dirent{{QID: QID{Type: 2}}},
 		},
 		&Tfsync{
@@ -367,7 +382,7 @@ func TestEncodeDecode(t *testing.T) {
 		// Encode the original.
 		data := make([]byte, initialBufferLength)
 		buf := buffer{data: data[:0]}
-		enc.Encode(&buf)
+		enc.encode(&buf)
 
 		// Create a new object, same as the first.
 		enc2 := reflect.New(reflect.ValueOf(enc).Elem().Type()).Interface().(encoder)
@@ -384,7 +399,7 @@ func TestEncodeDecode(t *testing.T) {
 		}
 
 		// Mark sure it was okay.
-		enc2.Decode(&buf2)
+		enc2.decode(&buf2)
 		if buf2.isOverrun() {
 			t.Errorf("object %#v->%#v got overrun on decode", enc, enc2)
 			continue
diff --git a/pkg/p9/p9.go b/pkg/p9/p9.go
index 25530adca..122c457d2 100644
--- a/pkg/p9/p9.go
+++ b/pkg/p9/p9.go
@@ -32,21 +32,21 @@ import (
 type OpenFlags uint32
 
 const (
-	// ReadOnly is a Topen and Tcreate flag indicating read-only mode.
+	// ReadOnly is a Tlopen and Tlcreate flag indicating read-only mode.
 	ReadOnly OpenFlags = 0
 
-	// WriteOnly is a Topen and Tcreate flag indicating write-only mode.
+	// WriteOnly is a Tlopen and Tlcreate flag indicating write-only mode.
 	WriteOnly OpenFlags = 1
 
-	// ReadWrite is a Topen flag indicates read-write mode.
+	// ReadWrite is a Tlopen flag indicates read-write mode.
 	ReadWrite OpenFlags = 2
 
 	// OpenFlagsModeMask is a mask of valid OpenFlags mode bits.
 	OpenFlagsModeMask OpenFlags = 3
 
-	// OpenFlagsIgnoreMask is a list of OpenFlags mode bits that are ignored for Tlopen.
-	// Note that syscall.O_LARGEFILE is set to zero, use value from Linux fcntl.h.
-	OpenFlagsIgnoreMask OpenFlags = syscall.O_DIRECTORY | syscall.O_NOATIME | 0100000
+	// OpenTruncate is a Tlopen flag indicating that the opened file should be
+	// truncated.
+	OpenTruncate OpenFlags = 01000
 )
 
 // ConnectFlags is the mode passed to Connect operations.
@@ -71,25 +71,32 @@ const (
 
 // OSFlags converts a p9.OpenFlags to an int compatible with open(2).
 func (o OpenFlags) OSFlags() int {
-	return int(o & OpenFlagsModeMask)
+	// "flags contains Linux open(2) flags bits" - 9P2000.L
+	return int(o)
 }
 
 // String implements fmt.Stringer.
 func (o OpenFlags) String() string {
-	switch o {
+	var buf strings.Builder
+	switch mode := o & OpenFlagsModeMask; mode {
 	case ReadOnly:
-		return "ReadOnly"
+		buf.WriteString("ReadOnly")
 	case WriteOnly:
-		return "WriteOnly"
+		buf.WriteString("WriteOnly")
 	case ReadWrite:
-		return "ReadWrite"
-	case OpenFlagsModeMask:
-		return "OpenFlagsModeMask"
-	case OpenFlagsIgnoreMask:
-		return "OpenFlagsIgnoreMask"
+		buf.WriteString("ReadWrite")
 	default:
-		return "UNDEFINED"
+		fmt.Fprintf(&buf, "%#o", mode)
 	}
+	otherFlags := o &^ OpenFlagsModeMask
+	if otherFlags&OpenTruncate != 0 {
+		buf.WriteString("|OpenTruncate")
+		otherFlags &^= OpenTruncate
+	}
+	if otherFlags != 0 {
+		fmt.Fprintf(&buf, "|%#o", otherFlags)
+	}
+	return buf.String()
 }
 
 // Tag is a message tag.
@@ -328,10 +335,18 @@ const (
 	MsgRgetattr             = 25
 	MsgTsetattr             = 26
 	MsgRsetattr             = 27
+	MsgTlistxattr           = 28
+	MsgRlistxattr           = 29
 	MsgTxattrwalk           = 30
 	MsgRxattrwalk           = 31
 	MsgTxattrcreate         = 32
 	MsgRxattrcreate         = 33
+	MsgTgetxattr            = 34
+	MsgRgetxattr            = 35
+	MsgTsetxattr            = 36
+	MsgRsetxattr            = 37
+	MsgTremovexattr         = 38
+	MsgRremovexattr         = 39
 	MsgTreaddir             = 40
 	MsgRreaddir             = 41
 	MsgTfsync               = 50
@@ -435,15 +450,15 @@ func (q QID) String() string {
 	return fmt.Sprintf("QID{Type: %d, Version: %d, Path: %d}", q.Type, q.Version, q.Path)
 }
 
-// Decode implements encoder.Decode.
-func (q *QID) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (q *QID) decode(b *buffer) {
 	q.Type = b.ReadQIDType()
 	q.Version = b.Read32()
 	q.Path = b.Read64()
 }
 
-// Encode implements encoder.Encode.
-func (q *QID) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (q *QID) encode(b *buffer) {
 	b.WriteQIDType(q.Type)
 	b.Write32(q.Version)
 	b.Write64(q.Path)
@@ -500,8 +515,8 @@ type FSStat struct {
 	NameLength uint32
 }
 
-// Decode implements encoder.Decode.
-func (f *FSStat) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (f *FSStat) decode(b *buffer) {
 	f.Type = b.Read32()
 	f.BlockSize = b.Read32()
 	f.Blocks = b.Read64()
@@ -513,8 +528,8 @@ func (f *FSStat) Decode(b *buffer) {
 	f.NameLength = b.Read32()
 }
 
-// Encode implements encoder.Encode.
-func (f *FSStat) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (f *FSStat) encode(b *buffer) {
 	b.Write32(f.Type)
 	b.Write32(f.BlockSize)
 	b.Write64(f.Blocks)
@@ -664,8 +679,8 @@ func (a AttrMask) String() string {
 	return fmt.Sprintf("AttrMask{with: %s}", strings.Join(masks, " "))
 }
 
-// Decode implements encoder.Decode.
-func (a *AttrMask) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (a *AttrMask) decode(b *buffer) {
 	mask := b.Read64()
 	a.Mode = mask&0x00000001 != 0
 	a.NLink = mask&0x00000002 != 0
@@ -683,8 +698,8 @@ func (a *AttrMask) Decode(b *buffer) {
 	a.DataVersion = mask&0x00002000 != 0
 }
 
-// Encode implements encoder.Encode.
-func (a *AttrMask) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (a *AttrMask) encode(b *buffer) {
 	var mask uint64
 	if a.Mode {
 		mask |= 0x00000001
@@ -759,8 +774,8 @@ func (a Attr) String() string {
 		a.Mode, a.UID, a.GID, a.NLink, a.RDev, a.Size, a.BlockSize, a.Blocks, a.ATimeSeconds, a.ATimeNanoSeconds, a.MTimeSeconds, a.MTimeNanoSeconds, a.CTimeSeconds, a.CTimeNanoSeconds, a.BTimeSeconds, a.BTimeNanoSeconds, a.Gen, a.DataVersion)
 }
 
-// Encode implements encoder.Encode.
-func (a *Attr) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (a *Attr) encode(b *buffer) {
 	b.WriteFileMode(a.Mode)
 	b.WriteUID(a.UID)
 	b.WriteGID(a.GID)
@@ -781,8 +796,8 @@ func (a *Attr) Encode(b *buffer) {
 	b.Write64(a.DataVersion)
 }
 
-// Decode implements encoder.Decode.
-func (a *Attr) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (a *Attr) decode(b *buffer) {
 	a.Mode = b.ReadFileMode()
 	a.UID = b.ReadUID()
 	a.GID = b.ReadGID()
@@ -814,7 +829,7 @@ func StatToAttr(s *syscall.Stat_t, req AttrMask) (Attr, AttrMask) {
 		attr.Mode = FileMode(s.Mode)
 	}
 	if req.NLink {
-		attr.NLink = s.Nlink
+		attr.NLink = uint64(s.Nlink)
 	}
 	if req.UID {
 		attr.UID = UID(s.Uid)
@@ -911,8 +926,8 @@ func (s SetAttrMask) Empty() bool {
 	return !s.Permissions && !s.UID && !s.GID && !s.Size && !s.ATime && !s.MTime && !s.CTime && !s.ATimeNotSystemTime && !s.MTimeNotSystemTime
 }
 
-// Decode implements encoder.Decode.
-func (s *SetAttrMask) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (s *SetAttrMask) decode(b *buffer) {
 	mask := b.Read32()
 	s.Permissions = mask&0x00000001 != 0
 	s.UID = mask&0x00000002 != 0
@@ -957,8 +972,8 @@ func (s SetAttrMask) bitmask() uint32 {
 	return mask
 }
 
-// Encode implements encoder.Encode.
-func (s *SetAttrMask) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (s *SetAttrMask) encode(b *buffer) {
 	b.Write32(s.bitmask())
 }
 
@@ -979,8 +994,8 @@ func (s SetAttr) String() string {
 	return fmt.Sprintf("SetAttr{Permissions: 0o%o, UID: %d, GID: %d, Size: %d, ATime: {Sec: %d, NanoSec: %d}, MTime: {Sec: %d, NanoSec: %d}}", s.Permissions, s.UID, s.GID, s.Size, s.ATimeSeconds, s.ATimeNanoSeconds, s.MTimeSeconds, s.MTimeNanoSeconds)
 }
 
-// Decode implements encoder.Decode.
-func (s *SetAttr) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (s *SetAttr) decode(b *buffer) {
 	s.Permissions = b.ReadPermissions()
 	s.UID = b.ReadUID()
 	s.GID = b.ReadGID()
@@ -991,8 +1006,8 @@ func (s *SetAttr) Decode(b *buffer) {
 	s.MTimeNanoSeconds = b.Read64()
 }
 
-// Encode implements encoder.Encode.
-func (s *SetAttr) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (s *SetAttr) encode(b *buffer) {
 	b.WritePermissions(s.Permissions)
 	b.WriteUID(s.UID)
 	b.WriteGID(s.GID)
@@ -1049,17 +1064,17 @@ func (d Dirent) String() string {
 	return fmt.Sprintf("Dirent{QID: %d, Offset: %d, Type: 0x%X, Name: %s}", d.QID, d.Offset, d.Type, d.Name)
 }
 
-// Decode implements encoder.Decode.
-func (d *Dirent) Decode(b *buffer) {
-	d.QID.Decode(b)
+// decode implements encoder.decode.
+func (d *Dirent) decode(b *buffer) {
+	d.QID.decode(b)
 	d.Offset = b.Read64()
 	d.Type = b.ReadQIDType()
 	d.Name = b.ReadString()
 }
 
-// Encode implements encoder.Encode.
-func (d *Dirent) Encode(b *buffer) {
-	d.QID.Encode(b)
+// encode implements encoder.encode.
+func (d *Dirent) encode(b *buffer) {
+	d.QID.encode(b)
 	b.Write64(d.Offset)
 	b.WriteQIDType(d.Type)
 	b.WriteString(d.Name)
@@ -1076,6 +1091,19 @@ type AllocateMode struct {
 	Unshare       bool
 }
 
+// ToAllocateMode returns an AllocateMode from a fallocate(2) mode.
+func ToAllocateMode(mode uint64) AllocateMode {
+	return AllocateMode{
+		KeepSize:      mode&unix.FALLOC_FL_KEEP_SIZE != 0,
+		PunchHole:     mode&unix.FALLOC_FL_PUNCH_HOLE != 0,
+		NoHideStale:   mode&unix.FALLOC_FL_NO_HIDE_STALE != 0,
+		CollapseRange: mode&unix.FALLOC_FL_COLLAPSE_RANGE != 0,
+		ZeroRange:     mode&unix.FALLOC_FL_ZERO_RANGE != 0,
+		InsertRange:   mode&unix.FALLOC_FL_INSERT_RANGE != 0,
+		Unshare:       mode&unix.FALLOC_FL_UNSHARE_RANGE != 0,
+	}
+}
+
 // ToLinux converts to a value compatible with fallocate(2)'s mode.
 func (a *AllocateMode) ToLinux() uint32 {
 	rv := uint32(0)
@@ -1103,8 +1131,8 @@ func (a *AllocateMode) ToLinux() uint32 {
 	return rv
 }
 
-// Decode implements encoder.Decode.
-func (a *AllocateMode) Decode(b *buffer) {
+// decode implements encoder.decode.
+func (a *AllocateMode) decode(b *buffer) {
 	mask := b.Read32()
 	a.KeepSize = mask&0x01 != 0
 	a.PunchHole = mask&0x02 != 0
@@ -1115,8 +1143,8 @@ func (a *AllocateMode) Decode(b *buffer) {
 	a.Unshare = mask&0x40 != 0
 }
 
-// Encode implements encoder.Encode.
-func (a *AllocateMode) Encode(b *buffer) {
+// encode implements encoder.encode.
+func (a *AllocateMode) encode(b *buffer) {
 	mask := uint32(0)
 	if a.KeepSize {
 		mask |= 0x01
diff --git a/pkg/p9/p9test/BUILD b/pkg/p9/p9test/BUILD
index 28707c0ca..7ca67cb19 100644
--- a/pkg/p9/p9test/BUILD
+++ b/pkg/p9/p9test/BUILD
@@ -1,5 +1,4 @@
-load("//tools/go_stateify:defs.bzl", "go_library")
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_test")
+load("//tools:defs.bzl", "go_binary", "go_library", "go_test")
 
 package(licenses = ["notice"])
 
@@ -64,12 +63,12 @@ go_library(
         "mocks.go",
         "p9test.go",
     ],
-    importpath = "gvisor.dev/gvisor/pkg/p9/p9test",
     visibility = ["//:sandbox"],
     deps = [
         "//pkg/fd",
         "//pkg/log",
         "//pkg/p9",
+        "//pkg/sync",
         "//pkg/unet",
         "@com_github_golang_mock//gomock:go_default_library",
     ],
@@ -79,10 +78,11 @@ go_test(
     name = "client_test",
     size = "medium",
     srcs = ["client_test.go"],
-    embed = [":p9test"],
+    library = ":p9test",
     deps = [
         "//pkg/fd",
         "//pkg/p9",
+        "//pkg/sync",
         "@com_github_golang_mock//gomock:go_default_library",
     ],
 )
diff --git a/pkg/p9/p9test/client_test.go b/pkg/p9/p9test/client_test.go
index 8bbdb2488..6e7bb3db2 100644
--- a/pkg/p9/p9test/client_test.go
+++ b/pkg/p9/p9test/client_test.go
@@ -22,7 +22,6 @@ import (
 	"os"
 	"reflect"
 	"strings"
-	"sync"
 	"syscall"
 	"testing"
 	"time"
@@ -30,6 +29,7 @@ import (
 	"github.com/golang/mock/gomock"
 	"gvisor.dev/gvisor/pkg/fd"
 	"gvisor.dev/gvisor/pkg/p9"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 func TestPanic(t *testing.T) {
@@ -1044,11 +1044,11 @@ func TestReaddir(t *testing.T) {
 			if _, err := f.Readdir(0, 1); err != syscall.EINVAL {
 				t.Errorf("readdir got %v, wanted EINVAL", err)
 			}
-			if _, _, _, err := f.Open(p9.ReadWrite); err != syscall.EINVAL {
-				t.Errorf("readdir got %v, wanted EINVAL", err)
+			if _, _, _, err := f.Open(p9.ReadWrite); err != syscall.EISDIR {
+				t.Errorf("readdir got %v, wanted EISDIR", err)
 			}
-			if _, _, _, err := f.Open(p9.WriteOnly); err != syscall.EINVAL {
-				t.Errorf("readdir got %v, wanted EINVAL", err)
+			if _, _, _, err := f.Open(p9.WriteOnly); err != syscall.EISDIR {
+				t.Errorf("readdir got %v, wanted EISDIR", err)
 			}
 			backend.EXPECT().Open(p9.ReadOnly).Times(1)
 			if _, _, _, err := f.Open(p9.ReadOnly); err != nil {
@@ -1065,75 +1065,93 @@ func TestReaddir(t *testing.T) {
 func TestOpen(t *testing.T) {
 	type openTest struct {
 		name  string
-		mode  p9.OpenFlags
+		flags p9.OpenFlags
 		err   error
 		match func(p9.FileMode) bool
 	}
 
 	cases := []openTest{
 		{
-			name:  "invalid",
-			mode:  ^p9.OpenFlagsModeMask,
-			err:   syscall.EINVAL,
-			match: func(p9.FileMode) bool { return true },
-		},
-		{
 			name:  "not-openable-read-only",
-			mode:  p9.ReadOnly,
+			flags: p9.ReadOnly,
 			err:   syscall.EINVAL,
 			match: func(mode p9.FileMode) bool { return !p9.CanOpen(mode) },
 		},
 		{
 			name:  "not-openable-write-only",
-			mode:  p9.WriteOnly,
+			flags: p9.WriteOnly,
 			err:   syscall.EINVAL,
 			match: func(mode p9.FileMode) bool { return !p9.CanOpen(mode) },
 		},
 		{
 			name:  "not-openable-read-write",
-			mode:  p9.ReadWrite,
+			flags: p9.ReadWrite,
 			err:   syscall.EINVAL,
 			match: func(mode p9.FileMode) bool { return !p9.CanOpen(mode) },
 		},
 		{
 			name:  "directory-read-only",
-			mode:  p9.ReadOnly,
+			flags: p9.ReadOnly,
 			err:   nil,
 			match: func(mode p9.FileMode) bool { return mode.IsDir() },
 		},
 		{
 			name:  "directory-read-write",
-			mode:  p9.ReadWrite,
-			err:   syscall.EINVAL,
+			flags: p9.ReadWrite,
+			err:   syscall.EISDIR,
 			match: func(mode p9.FileMode) bool { return mode.IsDir() },
 		},
 		{
 			name:  "directory-write-only",
-			mode:  p9.WriteOnly,
-			err:   syscall.EINVAL,
+			flags: p9.WriteOnly,
+			err:   syscall.EISDIR,
 			match: func(mode p9.FileMode) bool { return mode.IsDir() },
 		},
 		{
 			name:  "read-only",
-			mode:  p9.ReadOnly,
+			flags: p9.ReadOnly,
 			err:   nil,
 			match: func(mode p9.FileMode) bool { return p9.CanOpen(mode) },
 		},
 		{
 			name:  "write-only",
-			mode:  p9.WriteOnly,
+			flags: p9.WriteOnly,
 			err:   nil,
 			match: func(mode p9.FileMode) bool { return p9.CanOpen(mode) && !mode.IsDir() },
 		},
 		{
 			name:  "read-write",
-			mode:  p9.ReadWrite,
+			flags: p9.ReadWrite,
+			err:   nil,
+			match: func(mode p9.FileMode) bool { return p9.CanOpen(mode) && !mode.IsDir() },
+		},
+		{
+			name:  "directory-read-only-truncate",
+			flags: p9.ReadOnly | p9.OpenTruncate,
+			err:   syscall.EISDIR,
+			match: func(mode p9.FileMode) bool { return mode.IsDir() },
+		},
+		{
+			name:  "read-only-truncate",
+			flags: p9.ReadOnly | p9.OpenTruncate,
+			err:   nil,
+			match: func(mode p9.FileMode) bool { return p9.CanOpen(mode) && !mode.IsDir() },
+		},
+		{
+			name:  "write-only-truncate",
+			flags: p9.WriteOnly | p9.OpenTruncate,
+			err:   nil,
+			match: func(mode p9.FileMode) bool { return p9.CanOpen(mode) && !mode.IsDir() },
+		},
+		{
+			name:  "read-write-truncate",
+			flags: p9.ReadWrite | p9.OpenTruncate,
 			err:   nil,
 			match: func(mode p9.FileMode) bool { return p9.CanOpen(mode) && !mode.IsDir() },
 		},
 	}
 
-	// Open(mode OpenFlags) (*fd.FD, QID, uint32, error)
+	// Open(flags OpenFlags) (*fd.FD, QID, uint32, error)
 	// - only works on Regular, NamedPipe, BLockDevice, CharacterDevice
 	// - returning a file works as expected
 	for name := range newTypeMap(nil) {
@@ -1171,25 +1189,25 @@ func TestOpen(t *testing.T) {
 				// Attempt the given open.
 				if tc.err != nil {
 					// We expect an error, just test and return.
-					if _, _, _, err := f.Open(tc.mode); err != tc.err {
-						t.Fatalf("open with mode %v got %v, want %v", tc.mode, err, tc.err)
+					if _, _, _, err := f.Open(tc.flags); err != tc.err {
+						t.Fatalf("open with flags %v got %v, want %v", tc.flags, err, tc.err)
 					}
 					return
 				}
 
 				// Run an FD test, since we expect success.
 				fdTest(t, func(send *fd.FD) *fd.FD {
-					backend.EXPECT().Open(tc.mode).Return(send, p9.QID{}, uint32(0), nil).Times(1)
-					recv, _, _, err := f.Open(tc.mode)
+					backend.EXPECT().Open(tc.flags).Return(send, p9.QID{}, uint32(0), nil).Times(1)
+					recv, _, _, err := f.Open(tc.flags)
 					if err != tc.err {
-						t.Fatalf("open with mode %v got %v, want %v", tc.mode, err, tc.err)
+						t.Fatalf("open with flags %v got %v, want %v", tc.flags, err, tc.err)
 					}
 					return recv
 				})
 
 				// If the open was successful, attempt another one.
-				if _, _, _, err := f.Open(tc.mode); err != syscall.EINVAL {
-					t.Errorf("second open with mode %v got %v, want EINVAL", tc.mode, err)
+				if _, _, _, err := f.Open(tc.flags); err != syscall.EINVAL {
+					t.Errorf("second open with flags %v got %v, want EINVAL", tc.flags, err)
 				}
 
 				// Ensure that all illegal operations fail.
diff --git a/pkg/p9/p9test/p9test.go b/pkg/p9/p9test/p9test.go
index 4d3271b37..dd8b01b6d 100644
--- a/pkg/p9/p9test/p9test.go
+++ b/pkg/p9/p9test/p9test.go
@@ -17,13 +17,13 @@ package p9test
 
 import (
 	"fmt"
-	"sync"
 	"sync/atomic"
 	"syscall"
 	"testing"
 
 	"github.com/golang/mock/gomock"
 	"gvisor.dev/gvisor/pkg/p9"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/unet"
 )
 
diff --git a/pkg/p9/path_tree.go b/pkg/p9/path_tree.go
index 865459411..72ef53313 100644
--- a/pkg/p9/path_tree.go
+++ b/pkg/p9/path_tree.go
@@ -16,7 +16,8 @@ package p9
 
 import (
 	"fmt"
-	"sync"
+
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // pathNode is a single node in a path traversal.
diff --git a/pkg/p9/pool.go b/pkg/p9/pool.go
deleted file mode 100644
index 52de889e1..000000000
--- a/pkg/p9/pool.go
+++ /dev/null
@@ -1,68 +0,0 @@
-// Copyright 2018 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 p9
-
-import (
-	"sync"
-)
-
-// pool is a simple allocator.
-//
-// It is used for both tags and FIDs.
-type pool struct {
-	mu sync.Mutex
-
-	// cache is the set of returned values.
-	cache []uint64
-
-	// start is the starting value (if needed).
-	start uint64
-
-	// max is the current maximum issued.
-	max uint64
-
-	// limit is the upper limit.
-	limit uint64
-}
-
-// Get gets a value from the pool.
-func (p *pool) Get() (uint64, bool) {
-	p.mu.Lock()
-	defer p.mu.Unlock()
-
-	// Anything cached?
-	if len(p.cache) > 0 {
-		v := p.cache[len(p.cache)-1]
-		p.cache = p.cache[:len(p.cache)-1]
-		return v, true
-	}
-
-	// Over the limit?
-	if p.start == p.limit {
-		return 0, false
-	}
-
-	// Generate a new value.
-	v := p.start
-	p.start++
-	return v, true
-}
-
-// Put returns a value to the pool.
-func (p *pool) Put(v uint64) {
-	p.mu.Lock()
-	p.cache = append(p.cache, v)
-	p.mu.Unlock()
-}
diff --git a/pkg/p9/pool_test.go b/pkg/p9/pool_test.go
deleted file mode 100644
index e4746b8da..000000000
--- a/pkg/p9/pool_test.go
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright 2018 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 p9
-
-import (
-	"testing"
-)
-
-func TestPoolUnique(t *testing.T) {
-	p := pool{start: 1, limit: 3}
-	got := make(map[uint64]bool)
-
-	for {
-		n, ok := p.Get()
-		if !ok {
-			break
-		}
-
-		// Check unique.
-		if _, ok := got[n]; ok {
-			t.Errorf("pool spit out %v multiple times", n)
-		}
-
-		// Record.
-		got[n] = true
-	}
-}
-
-func TestExausted(t *testing.T) {
-	p := pool{start: 1, limit: 500}
-	for i := 0; i < 499; i++ {
-		_, ok := p.Get()
-		if !ok {
-			t.Fatalf("pool exhausted before 499 items")
-		}
-	}
-
-	_, ok := p.Get()
-	if ok {
-		t.Errorf("pool not exhausted when it should be")
-	}
-}
-
-func TestPoolRecycle(t *testing.T) {
-	p := pool{start: 1, limit: 500}
-	n1, _ := p.Get()
-	p.Put(n1)
-	n2, _ := p.Get()
-	if n1 != n2 {
-		t.Errorf("pool not recycling items")
-	}
-}
diff --git a/pkg/p9/server.go b/pkg/p9/server.go
index e717e6161..60cf94fa1 100644
--- a/pkg/p9/server.go
+++ b/pkg/p9/server.go
@@ -17,7 +17,6 @@ package p9
 import (
 	"io"
 	"runtime/debug"
-	"sync"
 	"sync/atomic"
 	"syscall"
 
@@ -25,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/fdchannel"
 	"gvisor.dev/gvisor/pkg/flipcall"
 	"gvisor.dev/gvisor/pkg/log"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/unet"
 )
 
@@ -453,7 +453,11 @@ func (cs *connState) initializeChannels() (err error) {
 		go func() { // S/R-SAFE: Server side.
 			defer cs.channelWg.Done()
 			if err := res.service(cs); err != nil {
-				log.Warningf("p9.channel.service: %v", err)
+				// Don't log flipcall.ShutdownErrors, which we expect to be
+				// returned during server shutdown.
+				if _, ok := err.(flipcall.ShutdownError); !ok {
+					log.Warningf("p9.channel.service: %v", err)
+				}
 			}
 		}()
 	}
@@ -478,10 +482,10 @@ func (cs *connState) handle(m message) (r message) {
 	defer func() {
 		if r == nil {
 			// Don't allow a panic to propagate.
-			recover()
+			err := recover()
 
 			// Include a useful log message.
-			log.Warningf("panic in handler: %s", debug.Stack())
+			log.Warningf("panic in handler: %v\n%s", err, debug.Stack())
 
 			// Wrap in an EFAULT error; we don't really have a
 			// better way to describe this kind of error. It will
diff --git a/pkg/p9/transport.go b/pkg/p9/transport.go
index 6e8b4bbcd..02e665345 100644
--- a/pkg/p9/transport.go
+++ b/pkg/p9/transport.go
@@ -19,11 +19,11 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
-	"sync"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/fd"
 	"gvisor.dev/gvisor/pkg/log"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/unet"
 )
 
@@ -66,21 +66,24 @@ const (
 var dataPool = sync.Pool{
 	New: func() interface{} {
 		// These buffers are used for decoding without a payload.
-		return make([]byte, initialBufferLength)
+		// We need to return a pointer to avoid unnecessary allocations
+		// (see https://staticcheck.io/docs/checks#SA6002).
+		b := make([]byte, initialBufferLength)
+		return &b
 	},
 }
 
 // send sends the given message over the socket.
 func send(s *unet.Socket, tag Tag, m message) error {
-	data := dataPool.Get().([]byte)
-	dataBuf := buffer{data: data[:0]}
+	data := dataPool.Get().(*[]byte)
+	dataBuf := buffer{data: (*data)[:0]}
 
 	if log.IsLogging(log.Debug) {
 		log.Debugf("send [FD %d] [Tag %06d] %s", s.FD(), tag, m.String())
 	}
 
 	// Encode the message. The buffer will grow automatically.
-	m.Encode(&dataBuf)
+	m.encode(&dataBuf)
 
 	// Get our vectors to send.
 	var hdr [headerLength]byte
@@ -141,7 +144,7 @@ func send(s *unet.Socket, tag Tag, m message) error {
 	}
 
 	// All set.
-	dataPool.Put(dataBuf.data)
+	dataPool.Put(&dataBuf.data)
 	return nil
 }
 
@@ -227,12 +230,29 @@ func recv(s *unet.Socket, msize uint32, lookup lookupTagAndType) (Tag, message,
 
 	// Not yet initialized.
 	var dataBuf buffer
+	var vecs [][]byte
+
+	appendBuffer := func(size int) *[]byte {
+		// Pull a data buffer from the pool.
+		datap := dataPool.Get().(*[]byte)
+		data := *datap
+		if size > len(data) {
+			// Create a larger data buffer.
+			data = make([]byte, size)
+			datap = &data
+		} else {
+			// Limit the data buffer.
+			data = data[:size]
+		}
+		dataBuf = buffer{data: data}
+		vecs = append(vecs, data)
+		return datap
+	}
 
 	// Read the rest of the payload.
 	//
 	// This requires some special care to ensure that the vectors all line
 	// up the way they should. We do this to minimize copying data around.
-	var vecs [][]byte
 	if payloader, ok := m.(payloader); ok {
 		fixedSize := payloader.FixedSize()
 
@@ -246,22 +266,8 @@ func recv(s *unet.Socket, msize uint32, lookup lookupTagAndType) (Tag, message,
 		}
 
 		if fixedSize != 0 {
-			// Pull a data buffer from the pool.
-			data := dataPool.Get().([]byte)
-			if int(fixedSize) > len(data) {
-				// Create a larger data buffer, ensuring
-				// sufficient capicity for the message.
-				data = make([]byte, fixedSize)
-				defer dataPool.Put(data)
-				dataBuf = buffer{data: data}
-				vecs = append(vecs, data)
-			} else {
-				// Limit the data buffer, and make sure it
-				// gets filled before the payload buffer.
-				defer dataPool.Put(data)
-				dataBuf = buffer{data: data[:fixedSize]}
-				vecs = append(vecs, data[:fixedSize])
-			}
+			datap := appendBuffer(int(fixedSize))
+			defer dataPool.Put(datap)
 		}
 
 		// Include the payload.
@@ -274,20 +280,8 @@ func recv(s *unet.Socket, msize uint32, lookup lookupTagAndType) (Tag, message,
 			vecs = append(vecs, p)
 		}
 	} else if remaining != 0 {
-		// Pull a data buffer from the pool.
-		data := dataPool.Get().([]byte)
-		if int(remaining) > len(data) {
-			// Create a larger data buffer.
-			data = make([]byte, remaining)
-			defer dataPool.Put(data)
-			dataBuf = buffer{data: data}
-			vecs = append(vecs, data)
-		} else {
-			// Limit the data buffer.
-			defer dataPool.Put(data)
-			dataBuf = buffer{data: data[:remaining]}
-			vecs = append(vecs, data[:remaining])
-		}
+		datap := appendBuffer(int(remaining))
+		defer dataPool.Put(datap)
 	}
 
 	if len(vecs) > 0 {
@@ -316,7 +310,7 @@ func recv(s *unet.Socket, msize uint32, lookup lookupTagAndType) (Tag, message,
 	}
 
 	// Decode the message data.
-	m.Decode(&dataBuf)
+	m.decode(&dataBuf)
 	if dataBuf.isOverrun() {
 		// No need to drain the socket.
 		return NoTag, nil, ErrNoValidMessage
diff --git a/pkg/p9/transport_flipcall.go b/pkg/p9/transport_flipcall.go
index 233f825e3..38038abdf 100644
--- a/pkg/p9/transport_flipcall.go
+++ b/pkg/p9/transport_flipcall.go
@@ -151,7 +151,7 @@ func (ch *channel) send(m message) (uint32, error) {
 	} else {
 		ch.buf.Write8(0) // No incoming FD.
 	}
-	m.Encode(&ch.buf)
+	m.encode(&ch.buf)
 	ssz := uint32(len(ch.buf.data)) // Updated below.
 
 	// Is there a payload?
@@ -205,7 +205,7 @@ func (ch *channel) recv(r message, rsz uint32) (message, error) {
 		ch.buf.data = ch.buf.data[:fs]
 	}
 
-	r.Decode(&ch.buf)
+	r.decode(&ch.buf)
 	if ch.buf.isOverrun() {
 		// Nothing valid was available.
 		log.Debugf("recv [got %d bytes, needed more]", rsz)
@@ -236,7 +236,7 @@ func (ch *channel) recv(r message, rsz uint32) (message, error) {
 
 	// Convert errors appropriately; see above.
 	if rlerr, ok := r.(*Rlerror); ok {
-		return nil, syscall.Errno(rlerr.Error)
+		return r, syscall.Errno(rlerr.Error)
 	}
 
 	return r, nil
diff --git a/pkg/p9/transport_test.go b/pkg/p9/transport_test.go
index 2f50ff3ea..e7406b374 100644
--- a/pkg/p9/transport_test.go
+++ b/pkg/p9/transport_test.go
@@ -56,8 +56,8 @@ func TestSendRecv(t *testing.T) {
 // badDecode overruns on decode.
 type badDecode struct{}
 
-func (*badDecode) Decode(b *buffer) { b.markOverrun() }
-func (*badDecode) Encode(b *buffer) {}
+func (*badDecode) decode(b *buffer) { b.markOverrun() }
+func (*badDecode) encode(b *buffer) {}
 func (*badDecode) Type() MsgType    { return MsgTypeBadDecode }
 func (*badDecode) String() string   { return "badDecode{}" }
 
@@ -81,8 +81,8 @@ func TestRecvOverrun(t *testing.T) {
 // unregistered is not registered on decode.
 type unregistered struct{}
 
-func (*unregistered) Decode(b *buffer) {}
-func (*unregistered) Encode(b *buffer) {}
+func (*unregistered) decode(b *buffer) {}
+func (*unregistered) encode(b *buffer) {}
 func (*unregistered) Type() MsgType    { return MsgTypeUnregistered }
 func (*unregistered) String() string   { return "unregistered{}" }
 
@@ -182,6 +182,8 @@ func TestSendClosed(t *testing.T) {
 }
 
 func BenchmarkSendRecv(b *testing.B) {
+	b.ReportAllocs()
+
 	server, client, err := unet.SocketPair(false)
 	if err != nil {
 		b.Fatalf("socketpair got err %v expected nil", err)
diff --git a/pkg/p9/version.go b/pkg/p9/version.go
index f1ffdd23a..09cde9f5a 100644
--- a/pkg/p9/version.go
+++ b/pkg/p9/version.go
@@ -26,7 +26,7 @@ const (
 	//
 	// Clients are expected to start requesting this version number and
 	// to continuously decrement it until a Tversion request succeeds.
-	highestSupportedVersion uint32 = 8
+	highestSupportedVersion uint32 = 11
 
 	// lowestSupportedVersion is the lowest supported version X in a
 	// version string of the format 9P2000.L.Google.X.
@@ -155,3 +155,21 @@ func versionSupportsTallocate(v uint32) bool {
 func versionSupportsFlipcall(v uint32) bool {
 	return v >= 8
 }
+
+// VersionSupportsOpenTruncateFlag returns true if version v supports
+// passing the OpenTruncate flag to Tlopen.
+func VersionSupportsOpenTruncateFlag(v uint32) bool {
+	return v >= 9
+}
+
+// versionSupportsGetSetXattr returns true if version v supports
+// the Tgetxattr and Tsetxattr messages.
+func versionSupportsGetSetXattr(v uint32) bool {
+	return v >= 10
+}
+
+// versionSupportsListRemoveXattr returns true if version v supports
+// the Tlistxattr and Tremovexattr messages.
+func versionSupportsListRemoveXattr(v uint32) bool {
+	return v >= 11
+}