fuse: add fsync support

Change-Id: Ia7351e70437df32b16648793dfc47d11ad8fdbea

third_party/code.google.com/p/rsc/fuse/fuse.go

@@ -545,7 +545,15 @@ func (c *Conn) ReadRequest() (Request, error) {
 		}
 
 	case opFsync:
-		panic("opFsync")
+		in := (*fsyncIn)(m.data())
+		if m.len() < unsafe.Sizeof(*in) {
+			goto corrupt
+		}
+		req = &FsyncRequest{
+			Header: m.Header(),
+			Handle: HandleID(in.Fh),
+			Flags:  in.FsyncFlags,
+		}
 
 	case opSetxattr:
 		var size uint32
@@ -1591,6 +1599,21 @@ func (r *MknodRequest) Respond(resp *LookupResponse) {
 	r.Conn.respond(&out.outHeader, unsafe.Sizeof(*out))
 }
 
+type FsyncRequest struct {
+	Header
+	Handle HandleID
+	Flags  uint32
+}
+
+func (r *FsyncRequest) String() string {
+	return fmt.Sprintf("Fsync [%s] Handle %v Flags %v", &r.Header, r.Handle, r.Flags)
+}
+
+func (r *FsyncRequest) Respond() {
+	out := &outHeader{Unique: uint64(r.ID)}
+	r.Conn.respond(out, unsafe.Sizeof(*out))
+}
+
 /*{
 
 // A XXXRequest xxx.

third_party/code.google.com/p/rsc/fuse/fuse_test.go

@@ -137,11 +137,12 @@ func (readAll1) test(path string, t *testing.T) {
 	readAll{}.test(path, t)
 }
 
-// Test Write calling basic Write.
+// Test Write calling basic Write, with an fsync thrown in too.
 
 type write struct {
 	file
-	data []byte
+	data     []byte
+	gotfsync bool
 }
 
 func (w *write) Write(req *WriteRequest, resp *WriteResponse, intr Intr) Error {
@@ -150,6 +151,11 @@ func (w *write) Write(req *WriteRequest, resp *WriteResponse, intr Intr) Error {
 	return nil
 }
 
+func (w *write) Fsync(r *FsyncRequest, intr Intr) Error {
+	w.gotfsync = true
+	return nil
+}
+
 func (w *write) test(path string, t *testing.T) {
 	log.Printf("pre-write Create")
 	f, err := os.Create(path)
@@ -164,6 +170,15 @@ func (w *write) test(path string, t *testing.T) {
 	if n != len(hi) {
 		t.Fatalf("short write; n=%d; hi=%d", n, len(hi))
 	}
+
+	err = syscall.Fsync(int(f.Fd()))
+	if err != nil {
+		t.Fatalf("Fsync = %v", err)
+	}
+	if !w.gotfsync {
+		t.Errorf("never received expected fsync call")
+	}
+
 	log.Printf("pre-write Close")
 	err = f.Close()
 	if err != nil {
@@ -179,7 +194,13 @@ func (w *write) test(path string, t *testing.T) {
 
 type writeAll struct {
 	file
-	data []byte
+	data     []byte
+	gotfsync bool
+}
+
+func (w *writeAll) Fsync(r *FsyncRequest, intr Intr) Error {
+	w.gotfsync = true
+	return nil
 }
 
 func (w *writeAll) WriteAll(data []byte, intr Intr) Error {
@@ -259,7 +280,7 @@ func (f *mkdir1) test(path string, t *testing.T) {
 	}
 }
 
-// Test Create
+// Test Create (and fsync)
 
 type create1 struct {
 	dir
@@ -280,6 +301,16 @@ func (f *create1) test(path string, t *testing.T) {
 		t.Errorf("create1 WriteFile: %v", err)
 		return
 	}
+
+	err = syscall.Fsync(int(ff.Fd()))
+	if err != nil {
+		t.Fatalf("Fsync = %v", err)
+	}
+
+	if !f.f.gotfsync {
+		t.Errorf("never received expected fsync call")
+	}
+
 	ff.Close()
 	if f.name != "foo" {
 		t.Errorf("create1 name=%q want foo", f.name)

third_party/code.google.com/p/rsc/fuse/serve.go

@@ -930,7 +930,26 @@ func (c *Conn) serve(fs FS, r Request) {
 		done(s)
 		r.Respond(s)
 
-		/*	case *FsyncRequest, *FsyncdirRequest:
+	case *FsyncRequest:
+		n, ok := node.(interface {
+			Fsync(r *FsyncRequest, intr Intr) Error
+		})
+		if !ok {
+			log.Printf("Node %T missing Fsync method", node)
+			done(EIO)
+			r.RespondError(EIO)
+			break
+		}
+		err := n.Fsync(r, intr)
+		if err != nil {
+			done(err)
+			r.RespondError(err)
+			break
+		}
+		done(nil)
+		r.Respond()
+
+		/*	case *FsyncdirRequest:
 				done(ENOSYS)
 				r.RespondError(ENOSYS)