nodefs: Rename2 support, kinda.

nodefs/api.go

@@ -91,7 +91,7 @@ type Node interface {
 	Mknod(ctx context.Context, name string, mode uint32, dev uint32, out *fuse.EntryOut) (*Inode, fuse.Status)
 	Rmdir(ctx context.Context, name string) fuse.Status
 	Unlink(ctx context.Context, name string) fuse.Status
-	Rename(ctx context.Context, name string, newParent Node, newName string) fuse.Status
+	Rename(ctx context.Context, name string, newParent Node, newName string, flags uint32) fuse.Status
 
 	Open(ctx context.Context, flags uint32) (fh File, fuseFlags uint32, code fuse.Status)
 

nodefs/bridge.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/hanwen/go-fuse/fuse"
+	"golang.org/x/sys/unix"
 )
 
 type mapEntry struct {
@@ -142,7 +143,7 @@ func (b *rawBridge) Lookup(header *fuse.InHeader, name string, out *fuse.EntryOu
 		return code
 	}
 
-	b.addNewChild(parent, name, child, out)
+	b.addNewChild(parent, name, child, nil, out)
 	b.setEntryOutTimeout(out)
 	return fuse.OK
 }
@@ -178,7 +179,7 @@ func (b *rawBridge) Mkdir(input *fuse.MkdirIn, name string, out *fuse.EntryOut)
 		log.Panicf("Mkdir: mode must be S_IFDIR (%o), got %o", fuse.S_IFDIR, out.Attr.Mode)
 	}
 
-	b.addNewChild(parent, name, child, out)
+	b.addNewChild(parent, name, child, nil, out)
 	b.setEntryOutTimeout(out)
 	return fuse.OK
 }
@@ -191,18 +192,26 @@ func (b *rawBridge) Mknod(input *fuse.MknodIn, name string, out *fuse.EntryOut)
 		return code
 	}
 
-	b.addNewChild(parent, name, child, out)
+	b.addNewChild(parent, name, child, nil, out)
 	b.setEntryOutTimeout(out)
 	return fuse.OK
 }
 
-func (b *rawBridge) addNewChild(parent *Inode, name string, child *Inode, out *fuse.EntryOut) {
+// addNewChild inserts the child into the tree. Returns file handle if file != nil.
+func (b *rawBridge) addNewChild(parent *Inode, name string, child *Inode, file File, out *fuse.EntryOut) uint64 {
 	lockNodes(parent, child)
 	parent.setEntry(name, child)
 	b.mu.Lock()
+	child.lookupCount++
 	if child.nodeID == 0 {
 		b.registerInode(child)
 	}
+
+	var fh uint64
+	if file != nil {
+		fh = b.registerFile(file)
+	}
+
 	out.NodeId = child.nodeID
 	// NOSUBMIT - or should let FS expose Attr.Ino? This makes
 	// testing semantics hard though, because os.Lstat doesn't
@@ -211,6 +220,7 @@ func (b *rawBridge) addNewChild(parent *Inode, name string, child *Inode, out *f
 	out.Generation = b.nodes[out.NodeId].generation
 	b.mu.Unlock()
 	unlockNodes(parent, child)
+	return fh
 }
 
 func (b *rawBridge) setEntryOutTimeout(out *fuse.EntryOut) {
@@ -252,19 +262,7 @@ func (b *rawBridge) Create(input *fuse.CreateIn, name string, out *fuse.CreateOu
 		return code
 	}
 
-	lockNode2(parent, child)
-	parent.setEntry(name, child)
-	b.mu.Lock()
-	if child.nodeID == 0 {
-		b.registerInode(child)
-	}
-	out.Fh = b.registerFile(f)
-	out.NodeId = child.nodeID
-	out.Ino = child.nodeID
-	out.Generation = b.nodes[child.nodeID].generation
-	b.mu.Unlock()
-	unlockNode2(parent, child)
-
+	out.Fh = b.addNewChild(parent, name, child, f, &out.EntryOut)
 	b.setEntryOutTimeout(&out.EntryOut)
 
 	out.OpenFlags = flags
@@ -278,10 +276,7 @@ func (b *rawBridge) Create(input *fuse.CreateIn, name string, out *fuse.CreateOu
 }
 
 func (b *rawBridge) Forget(nodeid, nlookup uint64) {
-	b.mu.Lock()
-	n := b.nodes[nodeid].inode
-	b.mu.Unlock()
-
+	n, _ := b.inode(nodeid, 0)
 	n.removeRef(nlookup, false)
 }
 
@@ -308,14 +303,18 @@ func (b *rawBridge) GetAttr(input *fuse.GetAttrIn, out *fuse.AttrOut) (code fuse
 		out.Nlink = 1
 	}
 
-	if b.options.AttrTimeout != nil {
-		out.SetTimeout(*b.options.AttrTimeout)
-	}
+	b.setAttrTimeout(out)
 
 	out.Ino = input.NodeId
 	return code
 }
 
+func (b *rawBridge) setAttrTimeout(out *fuse.AttrOut) {
+	if b.options.AttrTimeout != nil {
+		out.SetTimeout(*b.options.AttrTimeout)
+	}
+}
+
 func (b *rawBridge) SetAttr(input *fuse.SetAttrIn, out *fuse.AttrOut) (code fuse.Status) {
 	ctx := context.TODO()
 
@@ -379,18 +378,25 @@ func (b *rawBridge) SetAttr(input *fuse.SetAttrIn, out *fuse.AttrOut) (code fuse
 	// Must call GetAttr(); the filesystem may override some of
 	// the changes we effect here.
 	attr := &out.Attr
-	code = n.node.GetAttr(ctx, f, attr)
 
-	// TODO - attr timout?
+	// should take AttrOut
+	code = n.node.GetAttr(ctx, f, attr)
+	b.setAttrTimeout(out)
 	return code
 }
 
-func (b *rawBridge) Rename(input *fuse.RenameIn, oldName string, newName string) (code fuse.Status) {
+func (b *rawBridge) Rename(input *fuse.RenameIn, oldName string, newName string) fuse.Status {
 	p1, _ := b.inode(input.NodeId, 0)
 	p2, _ := b.inode(input.Newdir, 0)
 
-	if code := p1.node.Rename(context.TODO(), oldName, p2.node, newName); code.Ok() {
-		p1.MvChild(oldName, p2, newName, true)
+	code := p1.node.Rename(context.TODO(), oldName, p2.node, newName, input.Flags)
+	if code.Ok() {
+		if input.Flags&unix.RENAME_EXCHANGE != 0 {
+			// XXX - test coverage.
+			p1.ExchangeChild(oldName, p2, newName)
+		} else {
+			p1.MvChild(oldName, p2, newName, true)
+		}
 	}
 	return code
 }
@@ -541,5 +547,6 @@ func (b *rawBridge) FsyncDir(input *fuse.FsyncIn) (code fuse.Status) {
 func (b *rawBridge) StatFs(input *fuse.InHeader, out *fuse.StatfsOut) (code fuse.Status) {
 	return
 }
+
 func (b *rawBridge) Init(*fuse.Server) {
 }

nodefs/inode.go

@@ -279,6 +279,7 @@ func (n *Inode) removeRef(nlookup uint64, dropPersistence bool) (forgotten bool,
 	if nlookup > 0 && dropPersistence {
 		log.Panic("only one allowed")
 	} else if nlookup > 0 {
+
 		n.lookupCount -= nlookup
 		n.changeCounter++
 	} else if dropPersistence && n.persistent {
@@ -396,9 +397,8 @@ retry:
 	return true, true
 }
 
-// TODO - RENAME_NOREPLACE, RENAME_EXCHANGE MvChild executes a
-// rename. If overwrite is set, a child at the destination will be
-// overwritten.
+// MvChild executes a rename. If overwrite is set, a child at the
+// destination will be overwritten.
 func (n *Inode) MvChild(old string, newParent *Inode, newName string, overwrite bool) bool {
 retry:
 	for {
@@ -453,3 +453,64 @@ retry:
 		return true
 	}
 }
+
+func (n *Inode) ExchangeChild(oldName string, newParent *Inode, newName string) {
+	oldParent := n
+retry:
+	for {
+		lockNode2(oldParent, newParent)
+		counter1 := oldParent.changeCounter
+		counter2 := newParent.changeCounter
+
+		oldChild := oldParent.children[oldName]
+		destChild := newParent.children[newName]
+		unlockNode2(oldParent, newParent)
+
+		if destChild == nil && oldChild == nil {
+			return
+		}
+		if destChild == oldChild {
+			return
+		}
+
+		lockNodes(oldParent, newParent, oldChild, destChild)
+		if counter2 != newParent.changeCounter || counter1 != oldParent.changeCounter {
+			unlockNodes(oldParent, newParent, oldChild, destChild)
+			continue retry
+		}
+
+		// Detach
+		if oldChild != nil {
+			delete(oldParent.children, oldName)
+			delete(oldChild.parents, parentData{oldName, oldParent})
+			oldParent.changeCounter++
+			oldChild.changeCounter++
+		}
+
+		if destChild != nil {
+			delete(newParent.children, newName)
+			delete(destChild.parents, parentData{newName, newParent})
+			destChild.changeCounter++
+			newParent.changeCounter++
+		}
+
+		// Attach
+		if oldChild != nil {
+			newParent.children[newName] = oldChild
+			newParent.changeCounter++
+
+			oldChild.parents[parentData{newName, newParent}] = struct{}{}
+			oldChild.changeCounter++
+		}
+
+		if destChild != nil {
+			oldParent.children[oldName] = oldChild
+			oldParent.changeCounter++
+
+			destChild.parents[parentData{oldName, oldParent}] = struct{}{}
+			destChild.changeCounter++
+		}
+		unlockNodes(oldParent, newParent, oldChild, destChild)
+		return
+	}
+}

nodefs/loopback.go

@@ -123,7 +123,12 @@ func (n *loopbackNode) Unlink(ctx context.Context, name string) fuse.Status {
 	return fuse.ToStatus(err)
 }
 
-func (n *loopbackNode) Rename(ctx context.Context, name string, newParent Node, newName string) fuse.Status {
+func (n *loopbackNode) Rename(ctx context.Context, name string, newParent Node, newName string, flags uint32) fuse.Status {
+
+	if flags != 0 {
+		return fuse.ENOSYS
+	}
+
 	p1 := filepath.Join(n.path(), name)
 	var newParentLoopback *loopbackNode
 	if r, ok := newParent.(*loopbackRoot); ok {

nodefs/simple_test.go

@@ -14,6 +14,8 @@ import (
 	"testing"
 	"time"
 
+	"golang.org/x/sys/unix"
+
 	"github.com/hanwen/go-fuse/fuse"
 	"github.com/hanwen/go-fuse/internal/testutil"
 )
@@ -249,7 +251,7 @@ func TestMkdir(t *testing.T) {
 	}
 }
 
-func TestRename(t *testing.T) {
+func testRenameOverwrite(t *testing.T, destExists bool) {
 	tc := newTestCase(t)
 	defer tc.Clean()
 
@@ -260,6 +262,12 @@ func TestRename(t *testing.T) {
 		t.Fatalf("WriteFile: %v", err)
 	}
 
+	if destExists {
+		if err := ioutil.WriteFile(tc.origDir+"/dir/renamed", []byte("xx"), 0644); err != nil {
+			t.Fatalf("WriteFile: %v", err)
+		}
+	}
+
 	st := syscall.Stat_t{}
 	if err := syscall.Lstat(tc.mntDir+"/file", &st); err != nil {
 		t.Fatalf("Lstat before: %v", err)
@@ -281,3 +289,49 @@ func TestRename(t *testing.T) {
 		t.Errorf("got ino %d, want %d", got, beforeIno)
 	}
 }
+
+func TestRenameDestExist(t *testing.T) {
+	testRenameOverwrite(t, true)
+}
+
+func TestRenameDestNoExist(t *testing.T) {
+	testRenameOverwrite(t, false)
+}
+
+func TestRenameNoOverwrite(t *testing.T) {
+	tc := newTestCase(t)
+	defer tc.Clean()
+
+	if err := os.Mkdir(tc.origDir+"/dir", 0755); err != nil {
+		t.Fatalf("Mkdir: %v", err)
+	}
+	if err := ioutil.WriteFile(tc.origDir+"/file", []byte("hello"), 0644); err != nil {
+		t.Fatalf("WriteFile: %v", err)
+	}
+	if err := ioutil.WriteFile(tc.origDir+"/dir/file", []byte("x"), 0644); err != nil {
+		t.Fatalf("WriteFile: %v", err)
+	}
+
+	f1, err := syscall.Open(tc.mntDir+"/", syscall.O_DIRECTORY, 0)
+	if err != nil {
+		t.Fatalf("open 1: %v", err)
+	}
+	defer syscall.Close(f1)
+	f2, err := syscall.Open(tc.mntDir+"/dir", syscall.O_DIRECTORY, 0)
+	if err != nil {
+		t.Fatalf("open 2: %v", err)
+	}
+	defer syscall.Close(f2)
+
+	if err := unix.Renameat2(f1, "file", f2, "file", unix.RENAME_NOREPLACE); err == nil {
+		t.Errorf("rename NOREPLACE succeeded")
+	} else if err != syscall.EEXIST {
+		t.Errorf("got %v (%T) want EEXIST", err, err)
+	}
+
+	if err := unix.Renameat2(f1, "file", f2, "file", unix.RENAME_EXCHANGE); err == nil {
+		t.Errorf("rename EXCHANGE succeeded")
+	} else if err != syscall.EINVAL {
+		t.Errorf("got %v (%T) want %v (%T)", err, err, syscall.EINVAL, syscall.EINVAL)
+	}
+}