.

wcfs/misc.go

@@ -144,7 +144,7 @@ type fsOptions struct {
 	Sticky bool
 }
 
-var fSticky = &fsOptions{Sticky: true} // frequently used shortcut XXX -> newFSticky?
+var fSticky = &fsOptions{Sticky: true} // frequently used shortcut
 
 func (n *fsNode) Deletable() bool {
 	return !n.opt.Sticky
@@ -186,8 +186,8 @@ func (n *fsNode) path() string {
 //
 // Created file is sticky.
 func NewStaticFile(data []byte) *SmallFile {
-	return newSmallFile(func() []byte {
-		return data
+	return newSmallFile(func(_ *fuse.Context) ([]byte, error) {
+		return data, nil
 	}, fuse.FOPEN_KEEP_CACHE /*see ^^^*/)
 }
 
@@ -197,10 +197,10 @@ type SmallFile struct {
 	fuseFlags uint32 // fuse.FOPEN_*
 
 	// readData gives whole file data
-	readData func() []byte
+	readData func(fctx *fuse.Context) ([]byte, error)
 }
 
-func newSmallFile(readData func() []byte, fuseFlags uint32) *SmallFile {
+func newSmallFile(readData func(*fuse.Context) ([]byte, error), fuseFlags uint32) *SmallFile {
 	return &SmallFile{
 		fsNode:    newFSNode(&fsOptions{Sticky: true}),
 		fuseFlags: fuseFlags,
@@ -211,7 +211,7 @@ func newSmallFile(readData func() []byte, fuseFlags uint32) *SmallFile {
 // NewSmallFile creates nodefs.Node for file with dynamic, but always small, data.
 //
 // Created file is sticky.
-func NewSmallFile(readData func() []byte) *SmallFile {
+func NewSmallFile(readData func(*fuse.Context) ([]byte, error)) *SmallFile {
 	return newSmallFile(readData, fuse.FOPEN_DIRECT_IO)
 }
 
@@ -223,14 +223,20 @@ func (f *SmallFile) Open(flags uint32, _ *fuse.Context) (nodefs.File, fuse.Statu
 }
 
 func (f *SmallFile) GetAttr(out *fuse.Attr, _ nodefs.File, fctx *fuse.Context) fuse.Status {
-	data := f.readData() // XXX pass in fctx, so that the call could be canceled
+	data, err := f.readData(fctx)
+	if err != nil {
+		return err2LogStatus(err)
+	}
 	out.Size = uint64(len(data))
 	out.Mode = fuse.S_IFREG | 0644
 	return fuse.OK
 }
 
 func (f *SmallFile) Read(_ nodefs.File, dest []byte, off int64, fctx *fuse.Context) (fuse.ReadResult, fuse.Status) {
-	data := f.readData() // XXX +fctx -> cancel
+	data, err := f.readData(fctx)
+	if err != nil {
+		return nil, err2LogStatus(err)
+	}
 	l := int64(len(data))
 	end := off + l
 	if end > l {

wcfs/wcfs.go

@@ -2176,11 +2176,12 @@ func (f *BigFile) Close() error {
 // ---- misc ---
 
 // /(head|<rev>)/at -> readAt serves read.
-func (h *Head) readAt() []byte {
+func (h *Head) readAt(fctx *fuse.Context) ([]byte, error) {
+	// XXX cancel on fctx cancel
 	h.zheadMu.RLock()
 	defer h.zheadMu.RUnlock()
 
-	return []byte(h.zconn.At().String())
+	return []byte(h.zconn.At().String()), nil
 }
 
 // /(head|<rev>)/ -> Getattr serves stat.