fuse: add request.suppressReply

Replace some control flow with setting the boolean. Whether or not to
send a reply is part of the protocol (rather than I/O), so this should
be part of request and protocolServer.

Change-Id: Ia3eb27b0eca61caf8fcb649e75a6adb88a4b91f1

fuse/request.go

@@ -22,6 +22,8 @@ type request struct {
 
 	cancel chan struct{}
 
+	suppressReply bool
+
 	// written under Server.interruptMu
 	interrupted bool
 
@@ -77,7 +79,9 @@ func (r *request) outHeader() *OutHeader {
 	return (*OutHeader)(unsafe.Pointer(&r.outputBuf[0]))
 }
 
+// TODO - benchmark to see if this is necessary?
 func (r *request) clear() {
+	r.suppressReply = false
 	r.inputBuf = nil
 	r.outputBuf = nil
 	r.inPayload = nil

fuse/server.go

@@ -592,13 +592,15 @@ func (ms *Server) cancelAll() {
 }
 
 func (ms *Server) handleRequest(req *requestAlloc) Status {
+	defer ms.returnRequest(req)
 	if ms.opts.SingleThreaded {
 		ms.requestProcessingMu.Lock()
 		defer ms.requestProcessingMu.Unlock()
 	}
 
 	h, inSize, outSize, outPayloadSize, code := parseRequest(req.inputBuf, &ms.kernelSettings)
 	if !code.Ok() {
+		ms.opts.Logger.Printf("parseRequest: %v", code)
 		return code
 	}
 
@@ -609,31 +611,17 @@ func (ms *Server) handleRequest(req *requestAlloc) Status {
 	if outPayloadSize > 0 {
 		req.outPayload = ms.buffers.AllocBuffer(uint32(outPayloadSize))
 	}
-	code = ms.innerHandleRequest(h, &req.request)
-	ms.returnRequest(req)
+	ms.innerHandleRequest(h, &req.request)
+	code = ms.write(&req.request)
 	return code
 }
 
-func (ms *Server) innerHandleRequest(h *operationHandler, req *request) Status {
-	ms.addInflight(req)
-	defer ms.dropInflight(req)
-
-	if req.status.Ok() && ms.opts.Debug {
-		ms.opts.Logger.Println(req.InputDebug())
-	}
-
-	if req.inHeader().NodeId == pollHackInode ||
-		req.inHeader().NodeId == FUSE_ROOT_ID && h.FileNames > 0 && req.filename() == pollHackName {
-		doPollHackLookup(ms, req)
-	} else if req.status.Ok() && h.Func == nil {
-		ms.opts.Logger.Printf("Unimplemented opcode %v", operationName(req.inHeader().Opcode))
-		req.status = ENOSYS
-	} else if req.status.Ok() {
-		h.Func(ms, req)
+func (ms *Server) write(req *request) Status {
+	if req.suppressReply {
+		return OK
 	}
-
-	errNo := ms.write(req)
-	if errNo != 0 {
+	errno := ms.systemWrite(req)
+	if errno != 0 {
 		// Ignore ENOENT for INTERRUPT responses which
 		// indicates that the referred request is no longer
 		// known by the kernel. This is a normal if the
@@ -645,35 +633,55 @@ func (ms *Server) innerHandleRequest(h *operationHandler, req *request) Status {
 		// RELEASE. This is because RELEASE is analogous to
 		// FORGET, and is not synchronized with the calling
 		// process, but does require a response.
-		if ms.opts.Debug || !(errNo == ENOENT && (req.inHeader().Opcode == _OP_INTERRUPT ||
+		if ms.opts.Debug || !(errno == ENOENT && (req.inHeader().Opcode == _OP_INTERRUPT ||
 			req.inHeader().Opcode == _OP_RELEASEDIR ||
 			req.inHeader().Opcode == _OP_RELEASE)) {
 			ms.opts.Logger.Printf("writer: Write/Writev failed, err: %v. opcode: %v",
-				errNo, operationName(req.inHeader().Opcode))
+				errno, operationName(req.inHeader().Opcode))
 		}
 	}
-	return Status(errNo)
+	return errno
 }
 
-func (ms *Server) write(req *request) Status {
+func (ms *Server) innerHandleRequest(h *operationHandler, req *request) {
+	ms.addInflight(req)
+	defer ms.dropInflight(req)
+
+	if req.status.Ok() && ms.opts.Debug {
+		ms.opts.Logger.Println(req.InputDebug())
+	}
+
+	if req.inHeader().NodeId == pollHackInode ||
+		req.inHeader().NodeId == FUSE_ROOT_ID && h.FileNames > 0 && req.filename() == pollHackName {
+		doPollHackLookup(ms, req)
+	} else if req.status.Ok() && h.Func == nil {
+		ms.opts.Logger.Printf("Unimplemented opcode %v", operationName(req.inHeader().Opcode))
+		req.status = ENOSYS
+	} else if req.status.Ok() {
+		h.Func(ms, req)
+	}
+
 	// Forget/NotifyReply do not wait for reply from filesystem server.
 	switch req.inHeader().Opcode {
 	case _OP_FORGET, _OP_BATCH_FORGET, _OP_NOTIFY_REPLY:
-		return OK
+		req.suppressReply = true
 	case _OP_INTERRUPT:
+		// ? what other status can interrupt generate?
 		if req.status.Ok() {
-			return OK
+			req.suppressReply = true
 		}
 	}
 	if req.status == EINTR {
 		ms.interruptMu.Lock()
 		dead := ms.connectionDead
 		ms.interruptMu.Unlock()
 		if dead {
-			return OK
+			req.suppressReply = true
 		}
 	}
-
+	if req.suppressReply {
+		return
+	}
 	if req.inHeader().Opcode == _OP_INIT && ms.kernelSettings.Minor <= 22 {
 		// v8-v22 don't have TimeGran and further fields.
 		// This includes osxfuse (a.k.a. macfuse).
@@ -684,9 +692,6 @@ func (ms *Server) write(req *request) Status {
 	if ms.opts.Debug {
 		ms.opts.Logger.Println(req.OutputDebug())
 	}
-
-	s := ms.systemWrite(req)
-	return s
 }
 
 func (ms *Server) notifyWrite(req *request) Status {