fuse: implement LOOKUP for pollhack.

Some versions of FUSE need this; fixes pathfs owner tests.

fuse/opcode.go

@@ -129,22 +129,6 @@ func doOpen(server *Server, req *request) {
 
 func doCreate(server *Server, req *request) {
 	out := (*CreateOut)(req.outData)
-	if req.filenames[0] == pollHackName && req.inHeader.NodeId == FUSE_ROOT_ID {
-		out.EntryOut = EntryOut{
-			NodeId: pollHackInode,
-			Attr: Attr{
-				Ino:   pollHackInode,
-				Mode:  S_IFREG | 0644,
-				Nlink: 1,
-			},
-		}
-		out.OpenOut = OpenOut{
-			Fh: pollHackInode,
-		}
-		req.status = OK
-		return
-	}
-
 	status := server.fileSystem.Create((*CreateIn)(req.inData), req.filenames[0], out)
 	req.status = status
 }
@@ -262,9 +246,6 @@ func doGetAttr(server *Server, req *request) {
 
 // doForget - forget one NodeId
 func doForget(server *Server, req *request) {
-	if req.inHeader.NodeId == pollHackInode {
-		return
-	}
 	if !server.opts.RememberInodes {
 		server.fileSystem.Forget(req.inHeader.NodeId, (*ForgetIn)(req.inData).Nlookup)
 	}

fuse/pathfs/owner_test.go

@@ -37,6 +37,7 @@ func (fs *ownerFs) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse
 func setupOwnerTest(t *testing.T, opts *nodefs.Options) (workdir string, cleanup func()) {
 	wd := testutil.TempDir()
 
+	opts.Debug = testutil.VerboseTest()
 	fs := &ownerFs{NewDefaultFileSystem()}
 	nfs := NewPathNodeFs(fs, nil)
 	state, _, err := nodefs.MountRoot(wd, nfs.Root(), opts)
@@ -45,7 +46,7 @@ func setupOwnerTest(t *testing.T, opts *nodefs.Options) (workdir string, cleanup
 	}
 	go state.Serve()
 	if err := state.WaitMount(); err != nil {
-		t.Fatal("WaitMount", err)
+		t.Fatalf("WaitMount: %v", err)
 	}
 	return wd, func() {
 		state.Unmount()

fuse/poll.go

@@ -7,3 +7,28 @@ package fuse
 // can say ENOSYS and prevent further _OP_POLL requests.
 const pollHackName = ".go-fuse-epoll-hack"
 const pollHackInode = ^uint64(0)
+
+func doPollHackLookup(ms *Server, req *request) {
+	switch req.inHeader.Opcode {
+	case _OP_CREATE:
+		out := (*CreateOut)(req.outData)
+		out.EntryOut = EntryOut{
+			NodeId: pollHackInode,
+			Attr: Attr{
+				Ino:   pollHackInode,
+				Mode:  S_IFREG | 0644,
+				Nlink: 1,
+			},
+		}
+		out.OpenOut = OpenOut{
+			Fh: pollHackInode,
+		}
+		req.status = OK
+	case _OP_LOOKUP:
+		out := (*EntryOut)(req.outData)
+		*out = EntryOut{}
+		req.status = ENOENT
+	default:
+		req.status = EIO
+	}
+}

fuse/server.go

@@ -389,18 +389,19 @@ func (ms *Server) handleRequest(req *request) Status {
 		log.Println(req.InputDebug())
 	}
 
-	if req.inHeader.Opcode == _OP_POLL {
-		req.status = ENOSYS
-	} else if req.inHeader.NodeId == pollHackInode {
+	if req.inHeader.NodeId == pollHackInode {
 		// We want to avoid switching off features through our
 		// poll hack, so don't use ENOSYS
 		req.status = EIO
+		if req.inHeader.Opcode == _OP_POLL {
+			req.status = ENOSYS
+		}
+	} else if req.inHeader.NodeId == FUSE_ROOT_ID && len(req.filenames) > 0 && req.filenames[0] == pollHackName {
+		doPollHackLookup(ms, req)
 	} else if req.status.Ok() && req.handler.Func == nil {
 		log.Printf("Unimplemented opcode %v", operationName(req.inHeader.Opcode))
 		req.status = ENOSYS
-	}
-
-	if req.status.Ok() {
+	} else if req.status.Ok() {
 		req.handler.Func(ms, req)
 	}