From 5eb5a056bfbdd0a7a3ee94d12aaf9b1e7ab3c79e Mon Sep 17 00:00:00 2001
From: Jakob Borg <jakob@nym.se>
Date: Sat, 29 Mar 2014 18:53:48 +0100
Subject: [PATCH] Basic support for synchronizing multiple repositories (fixes
 #35)

---
 build.sh                        |   6 +-
 cmd/stcli/main.go               |   8 +-
 cmd/syncthing/config.go         |  15 ++
 cmd/syncthing/main.go           |  81 +-----
 cmd/syncthing/model.go          | 433 +++++++++++++++++++++++---------
 cmd/syncthing/model_test.go     |  18 +-
 cmd/syncthing/puller.go         |  84 +++----
 integration/.gitignore          |   4 +
 integration/h1/config.xml       |   8 +
 integration/h2/config.xml       |  16 ++
 integration/h3/config.xml       |   8 +
 integration/test.sh             |  39 ++-
 protocol/common_test.go         |   4 +-
 protocol/nativemodel_darwin.go  |   8 +-
 protocol/nativemodel_unix.go    |   8 +-
 protocol/nativemodel_windows.go |   8 +-
 protocol/protocol.go            |  38 +--
 protocol/wireformat.go          |   8 +-
 18 files changed, 492 insertions(+), 302 deletions(-)

diff --git a/build.sh b/build.sh
index cac937b1c..9ef62c978 100755
--- a/build.sh
+++ b/build.sh
@@ -14,7 +14,7 @@ build() {
 		go get -d ./cmd/syncthing
 		godep=
 	fi
-	${godep} go build -ldflags "-w -X main.Version $version" ./cmd/syncthing
+	${godep} go build $* -ldflags "-w -X main.Version $version" ./cmd/syncthing
 	${godep} go build -ldflags "-w -X main.Version $version" ./cmd/stcli
 }
 
@@ -61,6 +61,10 @@ case "$1" in
 		build
 		;;
 
+	race)
+		build -race
+		;;
+
 	test)
 		test
 		;;
diff --git a/cmd/stcli/main.go b/cmd/stcli/main.go
index e52b37f05..6e7ec11fe 100644
--- a/cmd/stcli/main.go
+++ b/cmd/stcli/main.go
@@ -78,8 +78,8 @@ func prtIndex(files []protocol.FileInfo) {
 	}
 }
 
-func (m Model) Index(nodeID string, files []protocol.FileInfo) {
-	log.Printf("Received index")
+func (m Model) Index(nodeID string, repo string, files []protocol.FileInfo) {
+	log.Printf("Received index for repo %q", repo)
 	if cmd == "idx" {
 		prtIndex(files)
 		if get != "" {
@@ -117,8 +117,8 @@ func getFile(f protocol.FileInfo) {
 	fd.Close()
 }
 
-func (m Model) IndexUpdate(nodeID string, files []protocol.FileInfo) {
-	log.Println("Received index update")
+func (m Model) IndexUpdate(nodeID string, repo string, files []protocol.FileInfo) {
+	log.Printf("Received index update for repo %q", repo)
 	if cmd == "idx" {
 		prtIndex(files)
 		if exit {
diff --git a/cmd/syncthing/config.go b/cmd/syncthing/config.go
index b8bdf4094..f0c7ecce3 100644
--- a/cmd/syncthing/config.go
+++ b/cmd/syncthing/config.go
@@ -19,6 +19,7 @@ type Configuration struct {
 }
 
 type RepositoryConfiguration struct {
+	ID        string              `xml:"id,attr"`
 	Directory string              `xml:"directory,attr"`
 	Nodes     []NodeConfiguration `xml:"node"`
 }
@@ -181,6 +182,20 @@ func readConfigXML(rd io.Reader) (Configuration, error) {
 	fillNilSlices(&cfg.Options)
 
 	cfg.Options.ListenAddress = uniqueStrings(cfg.Options.ListenAddress)
+
+	var seenRepos = map[string]bool{}
+	for i := range cfg.Repositories {
+		if cfg.Repositories[i].ID == "" {
+			cfg.Repositories[i].ID = "default"
+		}
+
+		id := cfg.Repositories[i].ID
+		if seenRepos[id] {
+			panic("duplicate repository ID " + id)
+		}
+		seenRepos[id] = true
+	}
+
 	return cfg, err
 }
 
diff --git a/cmd/syncthing/main.go b/cmd/syncthing/main.go
index 6acf7eb76..02d273b11 100644
--- a/cmd/syncthing/main.go
+++ b/cmd/syncthing/main.go
@@ -1,7 +1,6 @@
 package main
 
 import (
-	"compress/gzip"
 	"crypto/tls"
 	"flag"
 	"fmt"
@@ -20,7 +19,6 @@ import (
 	"github.com/calmh/ini"
 	"github.com/calmh/syncthing/discover"
 	"github.com/calmh/syncthing/protocol"
-	"github.com/calmh/syncthing/scanner"
 )
 
 const BlockSize = 128 * 1024
@@ -166,11 +164,6 @@ func main() {
 		infof("Edit %s to taste or use the GUI\n", cfgFile)
 	}
 
-	// Make sure the local node is in the node list.
-	cfg.Repositories[0].Nodes = cleanNodeList(cfg.Repositories[0].Nodes, myID)
-
-	var dir = expandTilde(cfg.Repositories[0].Directory)
-
 	if profiler := os.Getenv("STPROFILER"); len(profiler) > 0 {
 		go func() {
 			dlog.Println("Starting profiler on", profiler)
@@ -194,12 +187,18 @@ func main() {
 		MinVersion:             tls.VersionTLS12,
 	}
 
-	ensureDir(dir, -1)
-	m := NewModel(dir, cfg.Options.MaxChangeKbps*1000)
+	m := NewModel(cfg.Options.MaxChangeKbps * 1000)
 	if cfg.Options.MaxSendKbps > 0 {
 		m.LimitRate(cfg.Options.MaxSendKbps)
 	}
 
+	for i := range cfg.Repositories {
+		cfg.Repositories[i].Nodes = cleanNodeList(cfg.Repositories[i].Nodes, myID)
+		dir := expandTilde(cfg.Repositories[i].Directory)
+		ensureDir(dir, -1)
+		m.AddRepo(cfg.Repositories[i].ID, dir, cfg.Repositories[i].Nodes)
+	}
+
 	// GUI
 	if cfg.Options.GUIEnabled && cfg.Options.GUIAddress != "" {
 		addr, err := net.ResolveTCPAddr("tcp", cfg.Options.GUIAddress)
@@ -233,19 +232,9 @@ func main() {
 	if verbose {
 		infoln("Populating repository index")
 	}
-	loadIndex(m)
-
-	sup := &suppressor{threshold: int64(cfg.Options.MaxChangeKbps)}
-	w := &scanner.Walker{
-		Dir:            m.dir,
-		IgnoreFile:     ".stignore",
-		FollowSymlinks: cfg.Options.FollowSymlinks,
-		BlockSize:      BlockSize,
-		TempNamer:      defTempNamer,
-		Suppressor:     sup,
-		CurrentFiler:   m,
-	}
-	updateLocalModel(m, w)
+	m.LoadIndexes(confDir)
+	m.ScanRepos()
+	m.SaveIndexes(confDir)
 
 	connOpts := map[string]string{
 		"clientId":      "syncthing",
@@ -467,54 +456,6 @@ func discovery() *discover.Discoverer {
 	return disc
 }
 
-func updateLocalModel(m *Model, w *scanner.Walker) {
-	files, _ := w.Walk()
-	m.ReplaceLocal(files)
-	saveIndex(m)
-}
-
-func saveIndex(m *Model) {
-	name := m.RepoID() + ".idx.gz"
-	fullName := filepath.Join(confDir, name)
-	idxf, err := os.Create(fullName + ".tmp")
-	if err != nil {
-		return
-	}
-
-	gzw := gzip.NewWriter(idxf)
-
-	protocol.IndexMessage{
-		Repository: "local",
-		Files:      m.ProtocolIndex(),
-	}.EncodeXDR(gzw)
-	gzw.Close()
-	idxf.Close()
-
-	Rename(fullName+".tmp", fullName)
-}
-
-func loadIndex(m *Model) {
-	name := m.RepoID() + ".idx.gz"
-	idxf, err := os.Open(filepath.Join(confDir, name))
-	if err != nil {
-		return
-	}
-	defer idxf.Close()
-
-	gzr, err := gzip.NewReader(idxf)
-	if err != nil {
-		return
-	}
-	defer gzr.Close()
-
-	var im protocol.IndexMessage
-	err = im.DecodeXDR(gzr)
-	if err != nil || im.Repository != "local" {
-		return
-	}
-	m.SeedLocal(im.Files)
-}
-
 func ensureDir(dir string, mode int) {
 	fi, err := os.Stat(dir)
 	if os.IsNotExist(err) {
diff --git a/cmd/syncthing/model.go b/cmd/syncthing/model.go
index 7c53cca67..0e1d61b04 100644
--- a/cmd/syncthing/model.go
+++ b/cmd/syncthing/model.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"compress/gzip"
 	"crypto/sha1"
 	"errors"
 	"fmt"
@@ -20,28 +21,26 @@ import (
 )
 
 type Model struct {
-	dir string
-	cm  *cid.Map
-	fs  *files.Set
+	repoDirs  map[string]string     // repo -> dir
+	repoFiles map[string]*files.Set // repo -> files
+	repoNodes map[string][]string   // repo -> nodeIDs
+	nodeRepos map[string][]string   // nodeID -> repos
+	rmut      sync.RWMutex          // protects the above
+
+	cm *cid.Map
 
 	protoConn map[string]protocol.Connection
 	rawConn   map[string]io.Closer
 	pmut      sync.RWMutex // protects protoConn and rawConn
 
-	initOnce sync.Once
-
 	sup suppressor
 
 	limitRequestRate chan struct{}
 
-	imut sync.Mutex // protects Index
+	addedRepo bool
+	started   bool
 }
 
-const (
-	idxBcastHoldtime = 15 * time.Second  // Wait at least this long after the last index modification
-	idxBcastMaxDelay = 120 * time.Second // Unless we've already waited this long
-)
-
 var (
 	ErrNoSuchFile = errors.New("no such file")
 	ErrInvalid    = errors.New("file is invalid")
@@ -50,11 +49,13 @@ var (
 // NewModel creates and starts a new model. The model starts in read-only mode,
 // where it sends index information to connected peers and responds to requests
 // for file data without altering the local repository in any way.
-func NewModel(dir string, maxChangeBw int) *Model {
+func NewModel(maxChangeBw int) *Model {
 	m := &Model{
-		dir:       dir,
+		repoDirs:  make(map[string]string),
+		repoFiles: make(map[string]*files.Set),
+		repoNodes: make(map[string][]string),
+		nodeRepos: make(map[string][]string),
 		cm:        cid.NewMap(),
-		fs:        files.NewSet(),
 		protoConn: make(map[string]protocol.Connection),
 		rawConn:   make(map[string]io.Closer),
 		sup:       suppressor{threshold: int64(maxChangeBw)},
@@ -83,25 +84,32 @@ func (m *Model) LimitRate(kbps int) {
 // read/write mode the model will attempt to keep in sync with the cluster by
 // pulling needed files from peer nodes.
 func (m *Model) StartRW(threads int) {
-	m.initOnce.Do(func() {
-		newPuller("default", m.dir, m, threads)
-	})
+	m.rmut.Lock()
+	defer m.rmut.Unlock()
+
+	if !m.addedRepo {
+		panic("cannot start without repo")
+	}
+	m.started = true
+	for repo, dir := range m.repoDirs {
+		newPuller(repo, dir, m, threads)
+	}
 }
 
 // StartRO starts read only processing on the current model. When in
 // read only mode the model will announce files to the cluster but not
 // pull in any external changes.
 func (m *Model) StartRO() {
-	m.initOnce.Do(func() {
-		newPuller("default", m.dir, m, 0) // zero threads => read only
-	})
-}
+	m.rmut.Lock()
+	defer m.rmut.Unlock()
 
-// Generation returns an opaque integer that is guaranteed to increment on
-// every change to the local repository or global model.
-func (m *Model) Generation() uint64 {
-	c := m.fs.Changes(cid.LocalID)
-	return c
+	if !m.addedRepo {
+		panic("cannot start without repo")
+	}
+	m.started = true
+	for repo, dir := range m.repoDirs {
+		newPuller(repo, dir, m, 0) // zero threads => read only
+	}
 }
 
 type ConnectionInfo struct {
@@ -119,13 +127,7 @@ func (m *Model) ConnectionStats() map[string]ConnectionInfo {
 	}
 
 	m.pmut.RLock()
-
-	var tot int64
-	for _, f := range m.fs.Global() {
-		if f.Flags&protocol.FlagDeleted == 0 {
-			tot += f.Size
-		}
-	}
+	m.rmut.RLock()
 
 	var res = make(map[string]ConnectionInfo)
 	for node, conn := range m.protoConn {
@@ -138,10 +140,21 @@ func (m *Model) ConnectionStats() map[string]ConnectionInfo {
 			ci.Address = nc.RemoteAddr().String()
 		}
 
-		var have = tot
-		for _, f := range m.fs.Need(m.cm.Get(node)) {
-			if f.Flags&protocol.FlagDeleted == 0 {
-				have -= f.Size
+		var tot int64
+		var have int64
+
+		for _, repo := range m.nodeRepos[node] {
+			for _, f := range m.repoFiles[repo].Global() {
+				if f.Flags&protocol.FlagDeleted == 0 {
+					tot += f.Size
+					have += f.Size
+				}
+			}
+
+			for _, f := range m.repoFiles[repo].Need(m.cm.Get(node)) {
+				if f.Flags&protocol.FlagDeleted == 0 {
+					have -= f.Size
+				}
 			}
 		}
 
@@ -153,6 +166,7 @@ func (m *Model) ConnectionStats() map[string]ConnectionInfo {
 		res[node] = ci
 	}
 
+	m.rmut.RUnlock()
 	m.pmut.RUnlock()
 
 	return res
@@ -173,32 +187,54 @@ func sizeOf(fs []scanner.File) (files, deleted int, bytes int64) {
 // GlobalSize returns the number of files, deleted files and total bytes for all
 // files in the global model.
 func (m *Model) GlobalSize() (files, deleted int, bytes int64) {
-	fs := m.fs.Global()
+	m.rmut.RLock()
+	var fs []scanner.File
+	for _, rf := range m.repoFiles {
+		fs = append(fs, rf.Global()...)
+	}
+	m.rmut.RUnlock()
 	return sizeOf(fs)
 }
 
 // LocalSize returns the number of files, deleted files and total bytes for all
 // files in the local repository.
 func (m *Model) LocalSize() (files, deleted int, bytes int64) {
-	fs := m.fs.Have(cid.LocalID)
+	m.rmut.RLock()
+	var fs []scanner.File
+	for _, rf := range m.repoFiles {
+		fs = append(fs, rf.Have(cid.LocalID)...)
+	}
+	m.rmut.RUnlock()
 	return sizeOf(fs)
 }
 
 // InSyncSize returns the number and total byte size of the local files that
 // are in sync with the global model.
 func (m *Model) InSyncSize() (files int, bytes int64) {
-	gf := m.fs.Global()
-	hf := m.fs.Need(cid.LocalID)
+	var gf []scanner.File
+	var nf []scanner.File
+
+	m.rmut.RLock()
+	for _, rf := range m.repoFiles {
+		gf = append(gf, rf.Global()...)
+		nf = append(nf, rf.Need(cid.LocalID)...)
+	}
+	m.rmut.RUnlock()
 
 	gn, _, gb := sizeOf(gf)
-	hn, _, hb := sizeOf(hf)
+	nn, _, nb := sizeOf(nf)
 
-	return gn - hn, gb - hb
+	return gn - nn, gb - nb
 }
 
 // NeedFiles returns the list of currently needed files and the total size.
 func (m *Model) NeedFiles() ([]scanner.File, int64) {
-	nf := m.fs.Need(cid.LocalID)
+	var nf []scanner.File
+	m.rmut.RLock()
+	for _, rf := range m.repoFiles {
+		nf = append(nf, rf.Need(cid.LocalID)...)
+	}
+	m.rmut.RUnlock()
 
 	var bytes int64
 	for _, f := range nf {
@@ -210,24 +246,11 @@ func (m *Model) NeedFiles() ([]scanner.File, int64) {
 
 // Index is called when a new node is connected and we receive their full index.
 // Implements the protocol.Model interface.
-func (m *Model) Index(nodeID string, fs []protocol.FileInfo) {
-	var files = make([]scanner.File, len(fs))
-	for i := range fs {
-		lamport.Default.Tick(fs[i].Version)
-		files[i] = fileFromFileInfo(fs[i])
-	}
-
-	cid := m.cm.Get(nodeID)
-	m.fs.Replace(cid, files)
-
+func (m *Model) Index(nodeID string, repo string, fs []protocol.FileInfo) {
 	if debugNet {
-		dlog.Printf("IDX(in): %s: %d files", nodeID, len(fs))
+		dlog.Printf("IDX(in): %s / %q: %d files", nodeID, repo, len(fs))
 	}
-}
 
-// IndexUpdate is called for incremental updates to connected nodes' indexes.
-// Implements the protocol.Model interface.
-func (m *Model) IndexUpdate(nodeID string, fs []protocol.FileInfo) {
 	var files = make([]scanner.File, len(fs))
 	for i := range fs {
 		lamport.Default.Tick(fs[i].Version)
@@ -235,11 +258,36 @@ func (m *Model) IndexUpdate(nodeID string, fs []protocol.FileInfo) {
 	}
 
 	id := m.cm.Get(nodeID)
-	m.fs.Update(id, files)
-
-	if debugNet {
-		dlog.Printf("IDXUP(in): %s: %d files", nodeID, len(files))
+	m.rmut.RLock()
+	if r, ok := m.repoFiles[repo]; ok {
+		r.Replace(id, files)
+	} else {
+		warnf("Index from %s for nonexistant repo %q; dropping", nodeID, repo)
 	}
+	m.rmut.RUnlock()
+}
+
+// IndexUpdate is called for incremental updates to connected nodes' indexes.
+// Implements the protocol.Model interface.
+func (m *Model) IndexUpdate(nodeID string, repo string, fs []protocol.FileInfo) {
+	if debugNet {
+		dlog.Printf("IDXUP(in): %s / %q: %d files", nodeID, repo, len(fs))
+	}
+
+	var files = make([]scanner.File, len(fs))
+	for i := range fs {
+		lamport.Default.Tick(fs[i].Version)
+		files[i] = fileFromFileInfo(fs[i])
+	}
+
+	id := m.cm.Get(nodeID)
+	m.rmut.RLock()
+	if r, ok := m.repoFiles[repo]; ok {
+		r.Update(id, files)
+	} else {
+		warnf("Index update from %s for nonexistant repo %q; dropping", nodeID, repo)
+	}
+	m.rmut.RUnlock()
 }
 
 // Close removes the peer from the model and closes the underlying connection if possible.
@@ -255,7 +303,11 @@ func (m *Model) Close(node string, err error) {
 	}
 
 	cid := m.cm.Get(node)
-	m.fs.Replace(cid, nil)
+	m.rmut.RLock()
+	for _, repo := range m.nodeRepos[node] {
+		m.repoFiles[repo].Replace(cid, nil)
+	}
+	m.rmut.RUnlock()
 	m.cm.Clear(node)
 
 	m.pmut.Lock()
@@ -272,19 +324,31 @@ func (m *Model) Close(node string, err error) {
 // Implements the protocol.Model interface.
 func (m *Model) Request(nodeID, repo, name string, offset int64, size int) ([]byte, error) {
 	// Verify that the requested file exists in the local model.
-	lf := m.fs.Get(cid.LocalID, name)
+	m.rmut.RLock()
+	r, ok := m.repoFiles[repo]
+	m.rmut.RUnlock()
+
+	if !ok {
+		warnf("Request from %s for file %s in nonexistent repo %q", nodeID, name, repo)
+		return nil, ErrNoSuchFile
+	}
+
+	lf := r.Get(cid.LocalID, name)
 	if offset > lf.Size {
 		warnf("SECURITY (nonexistent file) REQ(in): %s: %q o=%d s=%d", nodeID, name, offset, size)
 		return nil, ErrNoSuchFile
 	}
+
 	if lf.Suppressed {
 		return nil, ErrInvalid
 	}
 
 	if debugNet && nodeID != "<local>" {
-		dlog.Printf("REQ(in): %s: %q o=%d s=%d", nodeID, name, offset, size)
+		dlog.Printf("REQ(in): %s: %q / %q o=%d s=%d", nodeID, repo, name, offset, size)
 	}
-	fn := filepath.Join(m.dir, name)
+	m.rmut.RLock()
+	fn := filepath.Join(m.repoDirs[repo], name)
+	m.rmut.RUnlock()
 	fd, err := os.Open(fn) // XXX: Inefficient, should cache fd?
 	if err != nil {
 		return nil, err
@@ -307,24 +371,34 @@ func (m *Model) Request(nodeID, repo, name string, offset int64, size int) ([]by
 }
 
 // ReplaceLocal replaces the local repository index with the given list of files.
-func (m *Model) ReplaceLocal(fs []scanner.File) {
-	m.fs.ReplaceWithDelete(cid.LocalID, fs)
+func (m *Model) ReplaceLocal(repo string, fs []scanner.File) {
+	m.rmut.RLock()
+	m.repoFiles[repo].ReplaceWithDelete(cid.LocalID, fs)
+	m.rmut.RUnlock()
 }
 
-// ReplaceLocal replaces the local repository index with the given list of files.
-func (m *Model) SeedLocal(fs []protocol.FileInfo) {
+func (m *Model) SeedLocal(repo string, fs []protocol.FileInfo) {
 	var sfs = make([]scanner.File, len(fs))
 	for i := 0; i < len(fs); i++ {
 		lamport.Default.Tick(fs[i].Version)
 		sfs[i] = fileFromFileInfo(fs[i])
 	}
 
-	m.fs.Replace(cid.LocalID, sfs)
+	m.rmut.RLock()
+	m.repoFiles[repo].Replace(cid.LocalID, sfs)
+	m.rmut.RUnlock()
+}
+
+type cFiler struct {
+	m *Model
+	r string
 }
 
 // Implements scanner.CurrentFiler
-func (m *Model) CurrentFile(file string) scanner.File {
-	f := m.fs.Get(cid.LocalID, file)
+func (cf cFiler) CurrentFile(file string) scanner.File {
+	cf.m.rmut.RLock()
+	f := cf.m.repoFiles[cf.r].Get(cid.LocalID, file)
+	cf.m.rmut.RUnlock()
 	return f
 }
 
@@ -336,11 +410,6 @@ func (m *Model) ConnectedTo(nodeID string) bool {
 	return ok
 }
 
-// RepoID returns a unique ID representing the current repository location.
-func (m *Model) RepoID() string {
-	return fmt.Sprintf("%x", sha1.Sum([]byte(m.dir)))
-}
-
 // AddConnection adds a new peer connection to the model. An initial index will
 // be sent to the connected peer, thereafter index updates whenever the local
 // repository changes.
@@ -358,20 +427,27 @@ func (m *Model) AddConnection(rawConn io.Closer, protoConn protocol.Connection)
 	m.pmut.Unlock()
 
 	go func() {
-		idx := m.ProtocolIndex()
-		if debugNet {
-			dlog.Printf("IDX(out/initial): %s: %d files", nodeID, len(idx))
+		m.rmut.RLock()
+		repos := m.nodeRepos[nodeID]
+		m.rmut.RUnlock()
+		for _, repo := range repos {
+			idx := m.ProtocolIndex(repo)
+			if debugNet {
+				dlog.Printf("IDX(out/initial): %s: %q: %d files", nodeID, repo, len(idx))
+			}
+			protoConn.Index(repo, idx)
 		}
-		protoConn.Index("default", idx)
 	}()
 }
 
 // ProtocolIndex returns the current local index in protocol data types.
 // Must be called with the read lock held.
-func (m *Model) ProtocolIndex() []protocol.FileInfo {
+func (m *Model) ProtocolIndex(repo string) []protocol.FileInfo {
 	var index []protocol.FileInfo
 
-	fs := m.fs.Have(cid.LocalID)
+	m.rmut.RLock()
+	fs := m.repoFiles[repo].Have(cid.LocalID)
+	m.rmut.RUnlock()
 
 	for _, f := range fs {
 		mf := fileInfoFromFile(f)
@@ -380,7 +456,7 @@ func (m *Model) ProtocolIndex() []protocol.FileInfo {
 			if mf.Flags&protocol.FlagDeleted != 0 {
 				flagComment = " (deleted)"
 			}
-			dlog.Printf("IDX(out): %q m=%d f=%o%s v=%d (%d blocks)", mf.Name, mf.Modified, mf.Flags, flagComment, mf.Version, len(mf.Blocks))
+			dlog.Printf("IDX(out): %q/%q m=%d f=%o%s v=%d (%d blocks)", repo, mf.Name, mf.Modified, mf.Flags, flagComment, mf.Version, len(mf.Blocks))
 		}
 		index = append(index, mf)
 	}
@@ -388,11 +464,13 @@ func (m *Model) ProtocolIndex() []protocol.FileInfo {
 	return index
 }
 
-func (m *Model) updateLocal(f scanner.File) {
-	m.fs.Update(cid.LocalID, []scanner.File{f})
+func (m *Model) updateLocal(repo string, f scanner.File) {
+	m.rmut.RLock()
+	m.repoFiles[repo].Update(cid.LocalID, []scanner.File{f})
+	m.rmut.RUnlock()
 }
 
-func (m *Model) requestGlobal(nodeID, name string, offset int64, size int, hash []byte) ([]byte, error) {
+func (m *Model) requestGlobal(nodeID, repo, name string, offset int64, size int, hash []byte) ([]byte, error) {
 	m.pmut.RLock()
 	nc, ok := m.protoConn[nodeID]
 	m.pmut.RUnlock()
@@ -402,52 +480,163 @@ func (m *Model) requestGlobal(nodeID, name string, offset int64, size int, hash
 	}
 
 	if debugNet {
-		dlog.Printf("REQ(out): %s: %q o=%d s=%d h=%x", nodeID, name, offset, size, hash)
+		dlog.Printf("REQ(out): %s: %q / %q o=%d s=%d h=%x", nodeID, repo, name, offset, size, hash)
 	}
 
-	return nc.Request("default", name, offset, size)
+	return nc.Request(repo, name, offset, size)
 }
 
 func (m *Model) broadcastIndexLoop() {
-	var lastChange uint64
+	var lastChange = map[string]uint64{}
 	for {
 		time.Sleep(5 * time.Second)
 
-		c := m.fs.Changes(cid.LocalID)
-		if c == lastChange {
-			continue
-		}
-		lastChange = c
-
-		saveIndex(m) // This should be cleaned up we don't do a lot of processing twice
-
-		fs := m.fs.Have(cid.LocalID)
-
-		var indexWg sync.WaitGroup
-		indexWg.Add(len(m.protoConn))
-
-		var idx = make([]protocol.FileInfo, len(fs))
-		for i, f := range fs {
-			idx[i] = fileInfoFromFile(f)
-		}
-
 		m.pmut.RLock()
-		for _, node := range m.protoConn {
-			node := node
-			if debugNet {
-				dlog.Printf("IDX(out/loop): %s: %d files", node.ID(), len(idx))
-			}
-			go func() {
-				node.Index("default", idx)
-				indexWg.Done()
-			}()
-		}
-		m.pmut.RUnlock()
+		m.rmut.RLock()
 
-		indexWg.Wait()
+		for repo, fs := range m.repoFiles {
+			c := fs.Changes(cid.LocalID)
+			if c == lastChange[repo] {
+				continue
+			}
+			lastChange[repo] = c
+
+			idx := m.ProtocolIndex(repo)
+			m.saveIndex(repo, confDir, idx)
+
+			var indexWg sync.WaitGroup
+			for _, nodeID := range m.repoNodes[repo] {
+				if conn, ok := m.protoConn[nodeID]; ok {
+					indexWg.Add(1)
+					if debugNet {
+						dlog.Printf("IDX(out/loop): %s: %d files", nodeID, len(idx))
+					}
+					go func() {
+						conn.Index(repo, idx)
+						indexWg.Done()
+					}()
+				}
+			}
+
+			indexWg.Wait()
+		}
+
+		m.rmut.RUnlock()
+		m.pmut.RUnlock()
 	}
 }
 
+func (m *Model) AddRepo(id, dir string, nodes []NodeConfiguration) {
+	if m.started {
+		panic("cannot add repo to started model")
+	}
+	if len(id) == 0 {
+		panic("cannot add empty repo id")
+	}
+
+	m.rmut.Lock()
+	m.repoDirs[id] = dir
+	m.repoFiles[id] = files.NewSet()
+
+	m.repoNodes[id] = make([]string, len(nodes))
+	for i, node := range nodes {
+		m.repoNodes[id][i] = node.NodeID
+		m.nodeRepos[node.NodeID] = append(m.nodeRepos[node.NodeID], id)
+	}
+
+	m.addedRepo = true
+	m.rmut.Unlock()
+}
+
+func (m *Model) ScanRepos() {
+	m.rmut.RLock()
+	for repo := range m.repoDirs {
+		m.ScanRepo(repo)
+	}
+	m.rmut.RUnlock()
+}
+
+func (m *Model) ScanRepo(repo string) {
+	sup := &suppressor{threshold: int64(cfg.Options.MaxChangeKbps)}
+	w := &scanner.Walker{
+		Dir:            m.repoDirs[repo],
+		IgnoreFile:     ".stignore",
+		FollowSymlinks: cfg.Options.FollowSymlinks,
+		BlockSize:      BlockSize,
+		TempNamer:      defTempNamer,
+		Suppressor:     sup,
+		CurrentFiler:   cFiler{m, repo},
+	}
+	fs, _ := w.Walk()
+	m.ReplaceLocal(repo, fs)
+}
+
+func (m *Model) SaveIndexes(dir string) {
+	m.rmut.RLock()
+	for repo := range m.repoDirs {
+		fs := m.ProtocolIndex(repo)
+		m.saveIndex(repo, dir, fs)
+	}
+	m.rmut.RUnlock()
+}
+
+func (m *Model) LoadIndexes(dir string) {
+	m.rmut.RLock()
+	for repo := range m.repoDirs {
+		fs := m.loadIndex(repo, dir)
+		m.SeedLocal(repo, fs)
+	}
+	m.rmut.RUnlock()
+}
+
+func (m *Model) saveIndex(repo string, dir string, fs []protocol.FileInfo) {
+	id := fmt.Sprintf("%x", sha1.Sum([]byte(m.repoDirs[repo])))
+	name := id + ".idx.gz"
+	name = filepath.Join(dir, name)
+
+	idxf, err := os.Create(name + ".tmp")
+	if err != nil {
+		return
+	}
+
+	gzw := gzip.NewWriter(idxf)
+
+	protocol.IndexMessage{
+		Repository: repo,
+		Files:      fs,
+	}.EncodeXDR(gzw)
+	gzw.Close()
+	idxf.Close()
+
+	Rename(name+".tmp", name)
+}
+
+func (m *Model) loadIndex(repo string, dir string) []protocol.FileInfo {
+	id := fmt.Sprintf("%x", sha1.Sum([]byte(m.repoDirs[repo])))
+	name := id + ".idx.gz"
+	name = filepath.Join(dir, name)
+
+	idxf, err := os.Open(name)
+	if err != nil {
+		return nil
+	}
+	defer idxf.Close()
+
+	gzr, err := gzip.NewReader(idxf)
+	if err != nil {
+		return nil
+	}
+	defer gzr.Close()
+
+	var im protocol.IndexMessage
+	err = im.DecodeXDR(gzr)
+	if err != nil || im.Repository != repo {
+		return nil
+	}
+
+	return im.Files
+}
+
 func fileFromFileInfo(f protocol.FileInfo) scanner.File {
 	var blocks = make([]scanner.Block, len(f.Blocks))
 	var offset int64
diff --git a/cmd/syncthing/model_test.go b/cmd/syncthing/model_test.go
index 186ff01bb..0dbf096bf 100644
--- a/cmd/syncthing/model_test.go
+++ b/cmd/syncthing/model_test.go
@@ -92,7 +92,7 @@ func BenchmarkIndex10000(b *testing.B) {
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		m.Index("42", files)
+		m.Index("42", "default", files)
 	}
 }
 
@@ -105,7 +105,7 @@ func BenchmarkIndex00100(b *testing.B) {
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		m.Index("42", files)
+		m.Index("42", "default", files)
 	}
 }
 
@@ -115,11 +115,11 @@ func BenchmarkIndexUpdate10000f10000(b *testing.B) {
 	fs, _ := w.Walk()
 	m.ReplaceLocal(fs)
 	files := genFiles(10000)
-	m.Index("42", files)
+	m.Index("42", "default", files)
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		m.IndexUpdate("42", files)
+		m.IndexUpdate("42", "default", files)
 	}
 }
 
@@ -129,12 +129,12 @@ func BenchmarkIndexUpdate10000f00100(b *testing.B) {
 	fs, _ := w.Walk()
 	m.ReplaceLocal(fs)
 	files := genFiles(10000)
-	m.Index("42", files)
+	m.Index("42", "default", files)
 
 	ufiles := genFiles(100)
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		m.IndexUpdate("42", ufiles)
+		m.IndexUpdate("42", "default", ufiles)
 	}
 }
 
@@ -144,12 +144,12 @@ func BenchmarkIndexUpdate10000f00001(b *testing.B) {
 	fs, _ := w.Walk()
 	m.ReplaceLocal(fs)
 	files := genFiles(10000)
-	m.Index("42", files)
+	m.Index("42", "default", files)
 
 	ufiles := genFiles(1)
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		m.IndexUpdate("42", ufiles)
+		m.IndexUpdate("42", "default", ufiles)
 	}
 }
 
@@ -206,7 +206,7 @@ func BenchmarkRequest(b *testing.B) {
 		requestData: []byte("some data to return"),
 	}
 	m.AddConnection(fc, fc)
-	m.Index("42", files)
+	m.Index("42", "default", files)
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
diff --git a/cmd/syncthing/puller.go b/cmd/syncthing/puller.go
index 6f30cf59f..cad660e68 100644
--- a/cmd/syncthing/puller.go
+++ b/cmd/syncthing/puller.go
@@ -111,7 +111,7 @@ func (p *puller) run() {
 			<-p.requestSlots
 			b := p.bq.get()
 			if debugPull {
-				dlog.Printf("filler: queueing %q offset %d copy %d", b.file.Name, b.block.Offset, len(b.copy))
+				dlog.Printf("filler: queueing %q / %q offset %d copy %d", p.repo, b.file.Name, b.block.Offset, len(b.copy))
 			}
 			p.blocks <- b
 		}
@@ -120,17 +120,6 @@ func (p *puller) run() {
 	walkTicker := time.Tick(time.Duration(cfg.Options.RescanIntervalS) * time.Second)
 	timeout := time.Tick(5 * time.Second)
 
-	sup := &suppressor{threshold: int64(cfg.Options.MaxChangeKbps)}
-	w := &scanner.Walker{
-		Dir:            p.dir,
-		IgnoreFile:     ".stignore",
-		FollowSymlinks: cfg.Options.FollowSymlinks,
-		BlockSize:      BlockSize,
-		TempNamer:      defTempNamer,
-		Suppressor:     sup,
-		CurrentFiler:   p.model,
-	}
-
 	for {
 		// Run the pulling loop as long as there are blocks to fetch
 	pull:
@@ -152,7 +141,7 @@ func (p *puller) run() {
 					break pull
 				}
 				if debugPull {
-					dlog.Printf("idle but have %d open files", len(p.openFiles))
+					dlog.Printf("%q: idle but have %d open files", p.repo, len(p.openFiles))
 					i := 5
 					for _, f := range p.openFiles {
 						dlog.Printf("  %v", f)
@@ -169,10 +158,9 @@ func (p *puller) run() {
 		select {
 		case <-walkTicker:
 			if debugPull {
-				dlog.Println("time for rescan")
+				dlog.Printf("%q: time for rescan", p.repo)
 			}
-			files, _ := w.Walk()
-			p.model.fs.ReplaceWithDelete(cid.LocalID, files)
+			p.model.ScanRepo(p.repo)
 
 		default:
 		}
@@ -185,23 +173,11 @@ func (p *puller) run() {
 func (p *puller) runRO() {
 	walkTicker := time.Tick(time.Duration(cfg.Options.RescanIntervalS) * time.Second)
 
-	sup := &suppressor{threshold: int64(cfg.Options.MaxChangeKbps)}
-	w := &scanner.Walker{
-		Dir:            p.dir,
-		IgnoreFile:     ".stignore",
-		FollowSymlinks: cfg.Options.FollowSymlinks,
-		BlockSize:      BlockSize,
-		TempNamer:      defTempNamer,
-		Suppressor:     sup,
-		CurrentFiler:   p.model,
-	}
-
 	for _ = range walkTicker {
 		if debugPull {
-			dlog.Println("time for rescan")
+			dlog.Printf("%q: time for rescan", p.repo)
 		}
-		files, _ := w.Walk()
-		p.model.fs.ReplaceWithDelete(cid.LocalID, files)
+		p.model.ScanRepo(p.repo)
 	}
 }
 
@@ -222,12 +198,12 @@ func (p *puller) handleRequestResult(res requestResult) {
 	p.openFiles[f.Name] = of
 
 	if debugPull {
-		dlog.Printf("pull: wrote %q offset %d outstanding %d done %v", f.Name, res.offset, of.outstanding, of.done)
+		dlog.Printf("pull: wrote %q / %q offset %d outstanding %d done %v", p.repo, f.Name, res.offset, of.outstanding, of.done)
 	}
 
 	if of.done && of.outstanding == 0 {
 		if debugPull {
-			dlog.Printf("pull: closing %q", f.Name)
+			dlog.Printf("pull: closing %q / %q", p.repo, f.Name)
 		}
 		of.file.Close()
 		defer os.Remove(of.temp)
@@ -237,7 +213,7 @@ func (p *puller) handleRequestResult(res requestResult) {
 		fd, err := os.Open(of.temp)
 		if err != nil {
 			if debugPull {
-				dlog.Printf("pull: error: %q: %v", f.Name, err)
+				dlog.Printf("pull: error: %q / %q: %v", p.repo, f.Name, err)
 			}
 			return
 		}
@@ -246,14 +222,14 @@ func (p *puller) handleRequestResult(res requestResult) {
 
 		if l0, l1 := len(hb), len(f.Blocks); l0 != l1 {
 			if debugPull {
-				dlog.Printf("pull: %q: nblocks %d != %d", f.Name, l0, l1)
+				dlog.Printf("pull: %q / %q: nblocks %d != %d", p.repo, f.Name, l0, l1)
 			}
 			return
 		}
 
 		for i := range hb {
 			if bytes.Compare(hb[i].Hash, f.Blocks[i].Hash) != 0 {
-				dlog.Printf("pull: %q: block %d hash mismatch", f.Name, i)
+				dlog.Printf("pull: %q / %q: block %d hash mismatch", p.repo, f.Name, i)
 				return
 			}
 		}
@@ -262,12 +238,12 @@ func (p *puller) handleRequestResult(res requestResult) {
 		os.Chtimes(of.temp, t, t)
 		os.Chmod(of.temp, os.FileMode(f.Flags&0777))
 		if debugPull {
-			dlog.Printf("pull: rename %q: %q", f.Name, of.filepath)
+			dlog.Printf("pull: rename %q / %q: %q", p.repo, f.Name, of.filepath)
 		}
 		if err := Rename(of.temp, of.filepath); err == nil {
-			p.model.fs.Update(cid.LocalID, []scanner.File{f})
+			p.model.updateLocal(p.repo, f)
 		} else {
-			dlog.Printf("pull: error: %q: %v", f.Name, err)
+			dlog.Printf("pull: error: %q / %q: %v", p.repo, f.Name, err)
 		}
 	}
 }
@@ -280,10 +256,10 @@ func (p *puller) handleBlock(b bqBlock) {
 
 	if !ok {
 		if debugPull {
-			dlog.Printf("pull: opening file %q", f.Name)
+			dlog.Printf("pull: %q: opening file %q", p.repo, f.Name)
 		}
 
-		of.availability = uint64(p.model.fs.Availability(f.Name))
+		of.availability = uint64(p.model.repoFiles[p.repo].Availability(f.Name))
 		of.filepath = filepath.Join(p.dir, f.Name)
 		of.temp = filepath.Join(p.dir, defTempNamer.TempName(f.Name))
 
@@ -293,13 +269,13 @@ func (p *puller) handleBlock(b bqBlock) {
 			err = os.MkdirAll(dirName, 0777)
 		}
 		if err != nil {
-			dlog.Printf("pull: error: %q: %v", f.Name, err)
+			dlog.Printf("pull: error: %q / %q: %v", p.repo, f.Name, err)
 		}
 
 		of.file, of.err = os.Create(of.temp)
 		if of.err != nil {
 			if debugPull {
-				dlog.Printf("pull: error: %q: %v", f.Name, of.err)
+				dlog.Printf("pull: error: %q / %q: %v", p.repo, f.Name, of.err)
 			}
 			if !b.last {
 				p.openFiles[f.Name] = of
@@ -312,10 +288,10 @@ func (p *puller) handleBlock(b bqBlock) {
 	if of.err != nil {
 		// We have already failed this file.
 		if debugPull {
-			dlog.Printf("pull: error: %q has already failed: %v", f.Name, of.err)
+			dlog.Printf("pull: error: %q / %q has already failed: %v", p.repo, f.Name, of.err)
 		}
 		if b.last {
-			dlog.Printf("pull: removing failed file %q", f.Name)
+			dlog.Printf("pull: removing failed file %q / %q", p.repo, f.Name)
 			delete(p.openFiles, f.Name)
 		}
 
@@ -346,14 +322,14 @@ func (p *puller) handleCopyBlock(b bqBlock) {
 	of := p.openFiles[f.Name]
 
 	if debugPull {
-		dlog.Printf("pull: copying %d blocks for %q", len(b.copy), f.Name)
+		dlog.Printf("pull: copying %d blocks for %q / %q", len(b.copy), p.repo, f.Name)
 	}
 
 	var exfd *os.File
 	exfd, of.err = os.Open(of.filepath)
 	if of.err != nil {
 		if debugPull {
-			dlog.Printf("pull: error: %q: %v", f.Name, of.err)
+			dlog.Printf("pull: error: %q / %q: %v", p.repo, f.Name, of.err)
 		}
 		of.file.Close()
 		of.file = nil
@@ -372,7 +348,7 @@ func (p *puller) handleCopyBlock(b bqBlock) {
 		buffers.Put(bs)
 		if of.err != nil {
 			if debugPull {
-				dlog.Printf("pull: error: %q: %v", f.Name, of.err)
+				dlog.Printf("pull: error: %q / %q: %v", p.repo, f.Name, of.err)
 			}
 			exfd.Close()
 			of.file.Close()
@@ -412,10 +388,10 @@ func (p *puller) handleRequestBlock(b bqBlock) {
 
 	go func(node string, b bqBlock) {
 		if debugPull {
-			dlog.Printf("pull: requesting %q offset %d size %d from %q outstanding %d", f.Name, b.block.Offset, b.block.Size, node, of.outstanding)
+			dlog.Printf("pull: requesting %q / %q offset %d size %d from %q outstanding %d", p.repo, f.Name, b.block.Offset, b.block.Size, node, of.outstanding)
 		}
 
-		bs, err := p.model.requestGlobal(node, f.Name, b.block.Offset, int(b.block.Size), nil)
+		bs, err := p.model.requestGlobal(node, p.repo, f.Name, b.block.Offset, int(b.block.Size), nil)
 		p.requestResults <- requestResult{
 			node:     node,
 			file:     f,
@@ -445,7 +421,7 @@ func (p *puller) handleEmptyBlock(b bqBlock) {
 		os.Remove(of.filepath)
 	} else {
 		if debugPull {
-			dlog.Printf("pull: no blocks to fetch and nothing to copy for %q", f.Name)
+			dlog.Printf("pull: no blocks to fetch and nothing to copy for %q / %q", p.repo, f.Name)
 		}
 		t := time.Unix(f.Modified, 0)
 		os.Chtimes(of.temp, t, t)
@@ -453,13 +429,13 @@ func (p *puller) handleEmptyBlock(b bqBlock) {
 		Rename(of.temp, of.filepath)
 	}
 	delete(p.openFiles, f.Name)
-	p.model.fs.Update(cid.LocalID, []scanner.File{f})
+	p.model.repoFiles[p.repo].Update(cid.LocalID, []scanner.File{f})
 }
 
 func (p *puller) queueNeededBlocks() {
 	queued := 0
-	for _, f := range p.model.fs.Need(cid.LocalID) {
-		lf := p.model.fs.Get(cid.LocalID, f.Name)
+	for _, f := range p.model.repoFiles[p.repo].Need(cid.LocalID) {
+		lf := p.model.repoFiles[p.repo].Get(cid.LocalID, f.Name)
 		have, need := scanner.BlockDiff(lf.Blocks, f.Blocks)
 		if debugNeed {
 			dlog.Printf("need:\n  local: %v\n  global: %v\n  haveBlocks: %v\n  needBlocks: %v", lf, f, have, need)
@@ -472,6 +448,6 @@ func (p *puller) queueNeededBlocks() {
 		})
 	}
 	if debugPull && queued > 0 {
-		dlog.Printf("queued %d blocks", queued)
+		dlog.Printf("%q: queued %d blocks", p.repo, queued)
 	}
 }
diff --git a/integration/.gitignore b/integration/.gitignore
index 898903296..ba94cadc9 100644
--- a/integration/.gitignore
+++ b/integration/.gitignore
@@ -1,6 +1,10 @@
 s1
 s2
 s3
+s12-1
+s12-2
+s23-2
+s23-3
 md5-*
 genfiles
 md5r
diff --git a/integration/h1/config.xml b/integration/h1/config.xml
index 4e313de87..2fc198170 100644
--- a/integration/h1/config.xml
+++ b/integration/h1/config.xml
@@ -10,6 +10,14 @@
             <address>127.0.0.1:22003</address>
         </node>
     </repository>
+    <repository id="s12" directory="s12-1">
+        <node id="I6KAH7666SLLL5PFXSOAUFJCDZYAOMLEKCP2GB3BV5RQST3PSROA" name="s1">
+            <address>127.0.0.1:22001</address>
+        </node>
+        <node id="JMFJCXBGZDE4BOCJE3VF65GYZNAIVJRET3J6HMRAUQIGJOFKNHMQ" name="s2">
+            <address>127.0.0.1:22002</address>
+        </node>
+    </repository>
     <options>
         <listenAddress>127.0.0.1:22001</listenAddress>
         <readOnly>false</readOnly>
diff --git a/integration/h2/config.xml b/integration/h2/config.xml
index 65ccf4e4c..fbfc9efca 100644
--- a/integration/h2/config.xml
+++ b/integration/h2/config.xml
@@ -10,6 +10,22 @@
             <address>127.0.0.1:22003</address>
         </node>
     </repository>
+    <repository id="s12" directory="s12-2">
+        <node id="I6KAH7666SLLL5PFXSOAUFJCDZYAOMLEKCP2GB3BV5RQST3PSROA" name="s1">
+            <address>127.0.0.1:22001</address>
+        </node>
+        <node id="JMFJCXBGZDE4BOCJE3VF65GYZNAIVJRET3J6HMRAUQIGJOFKNHMQ" name="s2">
+            <address>127.0.0.1:22002</address>
+        </node>
+    </repository>
+    <repository id="s23" directory="s23-2">
+        <node id="JMFJCXBGZDE4BOCJE3VF65GYZNAIVJRET3J6HMRAUQIGJOFKNHMQ" name="s2">
+            <address>127.0.0.1:22002</address>
+        </node>
+        <node id="373HSRPQLPNLIJYKZVQFP4PKZ6R2ZE6K3YD442UJHBGBQGWWXAHA" name="s3">
+            <address>127.0.0.1:22003</address>
+        </node>
+    </repository>
     <options>
         <listenAddress>127.0.0.1:22002</listenAddress>
         <readOnly>false</readOnly>
diff --git a/integration/h3/config.xml b/integration/h3/config.xml
index bdd23c5fa..ba506d2e2 100644
--- a/integration/h3/config.xml
+++ b/integration/h3/config.xml
@@ -10,6 +10,14 @@
             <address>127.0.0.1:22003</address>
         </node>
     </repository>
+    <repository id="s23" directory="s23-3">
+        <node id="JMFJCXBGZDE4BOCJE3VF65GYZNAIVJRET3J6HMRAUQIGJOFKNHMQ" name="s2">
+            <address>127.0.0.1:22002</address>
+        </node>
+        <node id="373HSRPQLPNLIJYKZVQFP4PKZ6R2ZE6K3YD442UJHBGBQGWWXAHA" name="s3">
+            <address>127.0.0.1:22003</address>
+        </node>
+    </repository>
     <options>
         <listenAddress>127.0.0.1:22003</listenAddress>
         <readOnly>false</readOnly>
diff --git a/integration/test.sh b/integration/test.sh
index 839468082..b92a56ac4 100755
--- a/integration/test.sh
+++ b/integration/test.sh
@@ -15,7 +15,7 @@ go build json.go
 testConvergence() {
 	echo "Starting..."
 	for i in 1 2 3 ; do
-		syncthing -home "h$i" &
+		STPROFILER=":909$i" syncthing -home "h$i" &
 	done
 
 	while true ; do
@@ -36,9 +36,11 @@ testConvergence() {
 	done
 
 	echo "Verifying..."
-	cat md5-* | sort | uniq > md5-tot
+	cat md5-? | sort | uniq > md5-tot
+	cat md5-12-? | sort | uniq > md5-12-tot
+	cat md5-23-? | sort | uniq > md5-23-tot
 
-	for i in 1 2 3 ; do
+	for i in 1 2 3 12-1 12-2 23-2 23-3; do
 		pushd "s$i" >/dev/null
 		../md5r -l | sort > ../md5-$i
 		popd >/dev/null
@@ -47,19 +49,35 @@ testConvergence() {
 	ok=0
 	for i in 1 2 3 ; do
 		if ! cmp "md5-$i" md5-tot >/dev/null ; then
-			echo "Fail: instance $i unconverged"
+			echo "Fail: instance $i unconverged for default"
 		else
 			ok=$(($ok + 1))
-			echo "OK: instance $i converged"
+			echo "OK: instance $i converged for default"
 		fi
 	done
-	if [[ $ok != 3 ]] ; then
+	for i in 12-1 12-2 ; do
+		if ! cmp "md5-$i" md5-12-tot >/dev/null ; then
+			echo "Fail: instance $i unconverged for s12"
+		else
+			ok=$(($ok + 1))
+			echo "OK: instance $i converged for s12"
+		fi
+	done
+	for i in 23-2 23-3 ; do
+		if ! cmp "md5-$i" md5-23-tot >/dev/null ; then
+			echo "Fail: instance $i unconverged for s23"
+		else
+			ok=$(($ok + 1))
+			echo "OK: instance $i converged for s23"
+		fi
+	done
+	if [[ $ok != 7 ]] ; then
 		exit 1
 	fi
 }
 
 echo "Setting up files..."
-for i in 1 2 3 ; do
+for i in 1 2 3 12-1 12-2 23-2 23-3; do
 	rm -f h$i/*.idx.gz
 	rm -rf "s$i"
 	mkdir "s$i"
@@ -74,7 +92,7 @@ for i in 1 2 3 ; do
 done
 
 echo "MD5-summing..."
-for i in 1 2 3 ; do
+for i in 1 2 3 12-1 12-2 23-2 23-3 ; do
 	pushd "s$i" >/dev/null
 	../md5r -l > ../md5-$i
 	popd >/dev/null
@@ -84,13 +102,14 @@ testConvergence
 
 for ((t = 0; t < $iterations; t++)) ; do
 	echo "Add and remove random files ($((t+1)) / $iterations)..."
-	for i in 1 2 3 ; do
+	for i in 1 2 3 12-1 12-2 23-2 23-3 ; do
 		pushd "s$i" >/dev/null
 		rm -rf */?[02468ace]
 		../genfiles -maxexp 22 -files 600
 		echo "  $i: append to large file"
 		dd if=/dev/urandom bs=1024k count=4 >> large-$i 2>/dev/null
-		../md5r -l | egrep -v "large-[^$i]" > ../md5-$i
+		../md5r -l > ../md5-tmp
+		(grep -v large ../md5-tmp ; grep "large-$i" ../md5-tmp) > ../md5-$i
 		popd >/dev/null
 	done
 
diff --git a/protocol/common_test.go b/protocol/common_test.go
index a24075e05..246d2b8fb 100644
--- a/protocol/common_test.go
+++ b/protocol/common_test.go
@@ -20,10 +20,10 @@ func newTestModel() *TestModel {
 	}
 }
 
-func (t *TestModel) Index(nodeID string, files []FileInfo) {
+func (t *TestModel) Index(nodeID string, repo string, files []FileInfo) {
 }
 
-func (t *TestModel) IndexUpdate(nodeID string, files []FileInfo) {
+func (t *TestModel) IndexUpdate(nodeID string, repo string, files []FileInfo) {
 }
 
 func (t *TestModel) Request(nodeID, repo, name string, offset int64, size int) ([]byte, error) {
diff --git a/protocol/nativemodel_darwin.go b/protocol/nativemodel_darwin.go
index 38b683e8e..f89a26941 100644
--- a/protocol/nativemodel_darwin.go
+++ b/protocol/nativemodel_darwin.go
@@ -10,18 +10,18 @@ type nativeModel struct {
 	next Model
 }
 
-func (m nativeModel) Index(nodeID string, files []FileInfo) {
+func (m nativeModel) Index(nodeID string, repo string, files []FileInfo) {
 	for i := range files {
 		files[i].Name = norm.NFD.String(files[i].Name)
 	}
-	m.next.Index(nodeID, files)
+	m.next.Index(nodeID, repo, files)
 }
 
-func (m nativeModel) IndexUpdate(nodeID string, files []FileInfo) {
+func (m nativeModel) IndexUpdate(nodeID string, repo string, files []FileInfo) {
 	for i := range files {
 		files[i].Name = norm.NFD.String(files[i].Name)
 	}
-	m.next.IndexUpdate(nodeID, files)
+	m.next.IndexUpdate(nodeID, repo, files)
 }
 
 func (m nativeModel) Request(nodeID, repo string, name string, offset int64, size int) ([]byte, error) {
diff --git a/protocol/nativemodel_unix.go b/protocol/nativemodel_unix.go
index 62f090c39..9739874fc 100644
--- a/protocol/nativemodel_unix.go
+++ b/protocol/nativemodel_unix.go
@@ -8,12 +8,12 @@ type nativeModel struct {
 	next Model
 }
 
-func (m nativeModel) Index(nodeID string, files []FileInfo) {
-	m.next.Index(nodeID, files)
+func (m nativeModel) Index(nodeID string, repo string, files []FileInfo) {
+	m.next.Index(nodeID, repo, files)
 }
 
-func (m nativeModel) IndexUpdate(nodeID string, files []FileInfo) {
-	m.next.IndexUpdate(nodeID, files)
+func (m nativeModel) IndexUpdate(nodeID string, repo string, files []FileInfo) {
+	m.next.IndexUpdate(nodeID, repo, files)
 }
 
 func (m nativeModel) Request(nodeID, repo string, name string, offset int64, size int) ([]byte, error) {
diff --git a/protocol/nativemodel_windows.go b/protocol/nativemodel_windows.go
index 083b56974..a7aeedf6f 100644
--- a/protocol/nativemodel_windows.go
+++ b/protocol/nativemodel_windows.go
@@ -10,18 +10,18 @@ type nativeModel struct {
 	next Model
 }
 
-func (m nativeModel) Index(nodeID string, files []FileInfo) {
+func (m nativeModel) Index(nodeID string, repo string, files []FileInfo) {
 	for i := range files {
 		files[i].Name = filepath.FromSlash(files[i].Name)
 	}
-	m.next.Index(nodeID, files)
+	m.next.Index(nodeID, repo, files)
 }
 
-func (m nativeModel) IndexUpdate(nodeID string, files []FileInfo) {
+func (m nativeModel) IndexUpdate(nodeID string, repo string, files []FileInfo) {
 	for i := range files {
 		files[i].Name = filepath.FromSlash(files[i].Name)
 	}
-	m.next.IndexUpdate(nodeID, files)
+	m.next.IndexUpdate(nodeID, repo, files)
 }
 
 func (m nativeModel) Request(nodeID, repo string, name string, offset int64, size int) ([]byte, error) {
diff --git a/protocol/protocol.go b/protocol/protocol.go
index 731d03fef..69ab7aaf6 100644
--- a/protocol/protocol.go
+++ b/protocol/protocol.go
@@ -1,6 +1,7 @@
 package protocol
 
 import (
+	"bufio"
 	"compress/flate"
 	"errors"
 	"fmt"
@@ -37,19 +38,19 @@ var (
 
 type Model interface {
 	// An index was received from the peer node
-	Index(nodeID string, files []FileInfo)
+	Index(nodeID string, repo string, files []FileInfo)
 	// An index update was received from the peer node
-	IndexUpdate(nodeID string, files []FileInfo)
+	IndexUpdate(nodeID string, repo string, files []FileInfo)
 	// A request was made by the peer node
-	Request(nodeID, repo string, name string, offset int64, size int) ([]byte, error)
+	Request(nodeID string, repo string, name string, offset int64, size int) ([]byte, error)
 	// The peer node closed the connection
 	Close(nodeID string, err error)
 }
 
 type Connection interface {
 	ID() string
-	Index(string, []FileInfo)
-	Request(repo, name string, offset int64, size int) ([]byte, error)
+	Index(repo string, files []FileInfo)
+	Request(repo string, name string, offset int64, size int) ([]byte, error)
 	Statistics() Statistics
 	Option(key string) string
 }
@@ -62,6 +63,7 @@ type rawConnection struct {
 	reader      io.ReadCloser
 	xr          *xdr.Reader
 	writer      io.WriteCloser
+	wb          *bufio.Writer
 	xw          *xdr.Writer
 	closed      chan struct{}
 	awaiting    map[int]chan asyncResult
@@ -73,8 +75,6 @@ type rawConnection struct {
 
 	hasSentIndex  bool
 	hasRecvdIndex bool
-
-	statisticsLock sync.Mutex
 }
 
 type asyncResult struct {
@@ -93,6 +93,7 @@ func NewConnection(nodeID string, reader io.Reader, writer io.Writer, receiver M
 	if err != nil {
 		panic(err)
 	}
+	wb := bufio.NewWriter(flwr)
 
 	c := rawConnection{
 		id:        nodeID,
@@ -100,7 +101,8 @@ func NewConnection(nodeID string, reader io.Reader, writer io.Writer, receiver M
 		reader:    flrd,
 		xr:        xdr.NewReader(flrd),
 		writer:    flwr,
-		xw:        xdr.NewWriter(flwr),
+		wb:        wb,
+		xw:        xdr.NewWriter(wb),
 		closed:    make(chan struct{}),
 		awaiting:  make(map[int]chan asyncResult),
 		indexSent: make(map[string]map[string][2]int64),
@@ -245,6 +247,7 @@ type flusher interface {
 }
 
 func (c *rawConnection) flush() error {
+	c.wb.Flush()
 	if f, ok := c.writer.(flusher); ok {
 		return f.Flush()
 	}
@@ -302,7 +305,15 @@ loop:
 				c.close(c.xr.Error())
 				break loop
 			} else {
-				c.receiver.Index(c.id, im.Files)
+
+				// We run this (and the corresponding one for update, below)
+				// in a separate goroutine to avoid blocking the read loop.
+				// There is otherwise a potential deadlock where both sides
+				// has the model locked because it's sending a large index
+				// update and can't receive the large index update from the
+				// other side.
+
+				go c.receiver.Index(c.id, im.Repository, im.Files)
 			}
 			c.Lock()
 			c.hasRecvdIndex = true
@@ -315,7 +326,7 @@ loop:
 				c.close(c.xr.Error())
 				break loop
 			} else {
-				c.receiver.IndexUpdate(c.id, im.Files)
+				go c.receiver.IndexUpdate(c.id, im.Repository, im.Files)
 			}
 
 		case messageTypeRequest:
@@ -454,16 +465,11 @@ type Statistics struct {
 }
 
 func (c *rawConnection) Statistics() Statistics {
-	c.statisticsLock.Lock()
-	defer c.statisticsLock.Unlock()
-
-	stats := Statistics{
+	return Statistics{
 		At:            time.Now(),
 		InBytesTotal:  int(c.xr.Tot()),
 		OutBytesTotal: int(c.xw.Tot()),
 	}
-
-	return stats
 }
 
 func (c *rawConnection) Option(key string) string {
diff --git a/protocol/wireformat.go b/protocol/wireformat.go
index 117a016c3..d3963ccf3 100644
--- a/protocol/wireformat.go
+++ b/protocol/wireformat.go
@@ -15,10 +15,14 @@ func (c wireFormatConnection) ID() string {
 }
 
 func (c wireFormatConnection) Index(node string, fs []FileInfo) {
+	var myFs = make([]FileInfo, len(fs))
+	copy(myFs, fs)
+
 	for i := range fs {
-		fs[i].Name = norm.NFC.String(filepath.ToSlash(fs[i].Name))
+		myFs[i].Name = norm.NFC.String(filepath.ToSlash(myFs[i].Name))
 	}
-	c.next.Index(node, fs)
+
+	c.next.Index(node, myFs)
 }
 
 func (c wireFormatConnection) Request(repo, name string, offset int64, size int) ([]byte, error) {