func (n *IpfsNode) loadFilesRoot() error {
	dsk := ds.NewKey("/local/filesroot")
	pf := func(ctx context.Context, k key.Key) error {
		return n.Repo.Datastore().Put(dsk, []byte(k))
	}

	var nd *merkledag.Node
	val, err := n.Repo.Datastore().Get(dsk)

	switch {
	case err == ds.ErrNotFound || val == nil:
		nd = uio.NewEmptyDirectory()
		_, err := n.DAG.Add(nd)
		if err != nil {
			return fmt.Errorf("failure writing to dagstore: %s", err)
		}
	case err == nil:
		k := key.Key(val.([]byte))
		nd, err = n.DAG.Get(n.Context(), k)
		if err != nil {
			return fmt.Errorf("error loading filesroot from DAG: %s", err)
		}
	default:
		return err
	}

	mr, err := mfs.NewRoot(n.Context(), n.DAG, nd, pf)
	if err != nil {
		return err
	}

	n.FilesRoot = mr
	return nil
}

func (i *gatewayHandler) putEmptyDirHandler(w http.ResponseWriter, r *http.Request) {
	newnode := uio.NewEmptyDirectory()

	key, err := i.node.DAG.Add(newnode)
	if err != nil {
		webError(w, "Could not recursively add new node", err, http.StatusInternalServerError)
		return
	}

	w.Header().Set("IPFS-Hash", key.String())
	http.Redirect(w, r, ipfsPathPrefix+key.String()+"/", http.StatusCreated)
}

func (i *gatewayHandler) putHandler(w http.ResponseWriter, r *http.Request) {
	// TODO(cryptix): move me to ServeHTTP and pass into all handlers
	ctx, cancel := context.WithCancel(i.node.Context())
	defer cancel()

	rootPath, err := path.ParsePath(r.URL.Path)
	if err != nil {
		webError(w, "putHandler: ipfs path not valid", err, http.StatusBadRequest)
		return
	}

	rsegs := rootPath.Segments()
	if rsegs[0] == ipnsPathPrefix {
		webError(w, "putHandler: updating named entries not supported", errors.New("WritableGateway: ipns put not supported"), http.StatusBadRequest)
		return
	}

	var newnode *dag.Node
	if rsegs[len(rsegs)-1] == "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn" {
		newnode = uio.NewEmptyDirectory()
	} else {
		putNode, err := i.newDagFromReader(r.Body)
		if err != nil {
			webError(w, "putHandler: Could not create DAG from request", err, http.StatusInternalServerError)
			return
		}
		newnode = putNode
	}

	var newPath string
	if len(rsegs) > 1 {
		newPath = path.Join(rsegs[2:])
	}

	var newkey key.Key
	rnode, err := core.Resolve(ctx, i.node, rootPath)
	switch ev := err.(type) {
	case path.ErrNoLink:
		// ev.Node < node where resolve failed
		// ev.Name < new link
		// but we need to patch from the root
		rnode, err := i.node.DAG.Get(ctx, key.B58KeyDecode(rsegs[1]))
		if err != nil {
			webError(w, "putHandler: Could not create DAG from request", err, http.StatusInternalServerError)
			return
		}

		e := dagutils.NewDagEditor(rnode, i.node.DAG)
		err = e.InsertNodeAtPath(ctx, newPath, newnode, uio.NewEmptyDirectory)
		if err != nil {
			webError(w, "putHandler: InsertNodeAtPath failed", err, http.StatusInternalServerError)
			return
		}

		nnode, err := e.Finalize(i.node.DAG)
		if err != nil {
			webError(w, "putHandler: could not get node", err, http.StatusInternalServerError)
			return
		}

		newkey, err = nnode.Key()
		if err != nil {
			webError(w, "putHandler: could not get key of edited node", err, http.StatusInternalServerError)
			return
		}

	case nil:
		// object set-data case
		rnode.Data = newnode.Data

		newkey, err = i.node.DAG.Add(rnode)
		if err != nil {
			nnk, _ := newnode.Key()
			rk, _ := rnode.Key()
			webError(w, fmt.Sprintf("putHandler: Could not add newnode(%q) to root(%q)", nnk.B58String(), rk.B58String()), err, http.StatusInternalServerError)
			return
		}
	default:
		log.Warningf("putHandler: unhandled resolve error %T", ev)
		webError(w, "could not resolve root DAG", ev, http.StatusInternalServerError)
		return
	}

	i.addUserHeaders(w) // ok, _now_ write user's headers.
	w.Header().Set("IPFS-Hash", newkey.String())
	http.Redirect(w, r, gopath.Join(ipfsPathPrefix, newkey.String(), newPath), http.StatusCreated)
}

func (i *gatewayHandler) putHandler(w http.ResponseWriter, r *http.Request) {
	// TODO(cryptix): either ask mildred about the flow of this or rewrite it
	webErrorWithCode(w, "Sorry, PUT is bugged right now, closing request", errors.New("handler disabled"), http.StatusInternalServerError)
	return
	urlPath := r.URL.Path
	pathext := urlPath[5:]
	var err error
	if urlPath == ipfsPathPrefix+"QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn/" {
		i.putEmptyDirHandler(w, r)
		return
	}

	var newnode *dag.Node
	if pathext[len(pathext)-1] == '/' {
		newnode = uio.NewEmptyDirectory()
	} else {
		newnode, err = i.newDagFromReader(r.Body)
		if err != nil {
			webError(w, "Could not create DAG from request", err, http.StatusInternalServerError)
			return
		}
	}

	ctx, cancel := context.WithCancel(i.node.Context())
	defer cancel()

	ipfsNode, err := core.Resolve(ctx, i.node, path.Path(urlPath))
	if err != nil {
		// FIXME HTTP error code
		webError(w, "Could not resolve name", err, http.StatusInternalServerError)
		return
	}

	k, err := ipfsNode.Key()
	if err != nil {
		webError(w, "Could not get key from resolved node", err, http.StatusInternalServerError)
		return
	}

	h, components, err := path.SplitAbsPath(path.FromKey(k))
	if err != nil {
		webError(w, "Could not split path", err, http.StatusInternalServerError)
		return
	}

	if len(components) < 1 {
		err = fmt.Errorf("Cannot override existing object")
		webError(w, "http gateway", err, http.StatusBadRequest)
		return
	}

	tctx, cancel := context.WithTimeout(ctx, time.Minute)
	defer cancel()
	// TODO(cryptix): could this be core.Resolve() too?
	rootnd, err := i.node.Resolver.DAG.Get(tctx, key.Key(h))
	if err != nil {
		webError(w, "Could not resolve root object", err, http.StatusBadRequest)
		return
	}

	// resolving path components into merkledag nodes. if a component does not
	// resolve, create empty directories (which will be linked and populated below.)
	pathNodes, err := i.node.Resolver.ResolveLinks(tctx, rootnd, components[:len(components)-1])
	if _, ok := err.(path.ErrNoLink); ok {
		// Create empty directories, links will be made further down the code
		for len(pathNodes) < len(components) {
			pathNodes = append(pathNodes, uio.NewDirectory(i.node.DAG).GetNode())
		}
	} else if err != nil {
		webError(w, "Could not resolve parent object", err, http.StatusBadRequest)
		return
	}

	for i := len(pathNodes) - 1; i >= 0; i-- {
		newnode, err = pathNodes[i].UpdateNodeLink(components[i], newnode)
		if err != nil {
			webError(w, "Could not update node links", err, http.StatusInternalServerError)
			return
		}
	}

	err = i.node.DAG.AddRecursive(newnode)
	if err != nil {
		webError(w, "Could not add recursively new node", err, http.StatusInternalServerError)
		return
	}

	// Redirect to new path
	key, err := newnode.Key()
	if err != nil {
		webError(w, "Could not get key of new node", err, http.StatusInternalServerError)
		return
	}

	i.addUserHeaders(w) // ok, _now_ write user's headers.
	w.Header().Set("IPFS-Hash", key.String())
	http.Redirect(w, r, ipfsPathPrefix+key.String()+"/"+strings.Join(components, "/"), http.StatusCreated)
}