From 82ca11faa9045023166b0a3781b694d9dc076f18 Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Mon, 1 Dec 2014 14:30:50 -0600
Subject: [PATCH] Destroy the torrent FS on exit signals so ongoing syscalls
 don't block the unmount

---
 cmd/torrentfs/main.go | 19 +++++++++----------
 fs/torrentfs.go       | 24 ++++++++++++------------
 2 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/cmd/torrentfs/main.go b/cmd/torrentfs/main.go
index fa9389e4..ec31aa67 100644
--- a/cmd/torrentfs/main.go
+++ b/cmd/torrentfs/main.go
@@ -57,18 +57,17 @@ func resolveTestPeerAddr() {
 	}
 }
 
-func setSignalHandlers() {
+func exitSignalHandlers(fs *torrentfs.TorrentFS) {
 	c := make(chan os.Signal)
 	signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
-	go func() {
-		for {
-			<-c
-			err := fuse.Unmount(mountDir)
-			if err != nil {
-				log.Print(err)
-			}
+	for {
+		<-c
+		fs.Destroy()
+		err := fuse.Unmount(*mountDir)
+		if err != nil {
+			log.Print(err)
 		}
-	}()
+	}
 }
 
 func addTestPeer(client *torrent.Client) {
@@ -104,7 +103,6 @@ func main() {
 	}
 	defer fuse.Unmount(mountDir)
 	// TODO: Think about the ramifications of exiting not due to a signal.
-	setSignalHandlers()
 	defer conn.Close()
 	client, err := torrent.NewClient(&torrent.Config{
 		DataDir:          downloadDir,
@@ -145,6 +143,7 @@ func main() {
 	}()
 	resolveTestPeerAddr()
 	fs := torrentfs.New(client)
+	go exitSignalHandlers(fs)
 	go func() {
 		for {
 			addTestPeer(client)
diff --git a/fs/torrentfs.go b/fs/torrentfs.go
index 18012d89..835db462 100644
--- a/fs/torrentfs.go
+++ b/fs/torrentfs.go
@@ -24,18 +24,18 @@ var (
 	interruptedReads             = expvar.NewInt("interruptedReads")
 )
 
-type torrentFS struct {
+type TorrentFS struct {
 	Client    *torrent.Client
 	destroyed chan struct{}
 	mu        sync.Mutex
 }
 
 var (
-	_ fusefs.FSDestroyer = &torrentFS{}
-	_ fusefs.FSIniter    = &torrentFS{}
+	_ fusefs.FSDestroyer = &TorrentFS{}
+	_ fusefs.FSIniter    = &TorrentFS{}
 )
 
-func (fs *torrentFS) Init(req *fuse.InitRequest, resp *fuse.InitResponse, intr fusefs.Intr) fuse.Error {
+func (fs *TorrentFS) Init(req *fuse.InitRequest, resp *fuse.InitResponse, intr fusefs.Intr) fuse.Error {
 	log.Print(req)
 	log.Print(resp)
 	resp.MaxReadahead = req.MaxReadahead
@@ -46,13 +46,13 @@ func (fs *torrentFS) Init(req *fuse.InitRequest, resp *fuse.InitResponse, intr f
 var _ fusefs.NodeForgetter = rootNode{}
 
 type rootNode struct {
-	fs *torrentFS
+	fs *TorrentFS
 }
 
 type node struct {
 	path     []string
 	metadata *torrent.MetaInfo
-	FS       *torrentFS
+	FS       *TorrentFS
 	InfoHash torrent.InfoHash
 }
 
@@ -72,7 +72,7 @@ func (n *node) fsPath() string {
 	return "/" + strings.Join(append([]string{n.metadata.Name}, n.path...), "/")
 }
 
-func blockingRead(fs *torrentFS, ih torrent.InfoHash, off int64, p []byte, intr fusefs.Intr) (n int, err fuse.Error) {
+func blockingRead(fs *TorrentFS, ih torrent.InfoHash, off int64, p []byte, intr fusefs.Intr) (n int, err fuse.Error) {
 	dataWaiter := fs.Client.DataWaiter(ih, off)
 	select {
 	case <-dataWaiter:
@@ -87,7 +87,7 @@ func blockingRead(fs *torrentFS, ih torrent.InfoHash, off int64, p []byte, intr
 	return
 }
 
-func readFull(fs *torrentFS, ih torrent.InfoHash, off int64, p []byte, intr fusefs.Intr) (n int, err fuse.Error) {
+func readFull(fs *TorrentFS, ih torrent.InfoHash, off int64, p []byte, intr fusefs.Intr) (n int, err fuse.Error) {
 	for len(p) != 0 {
 		var nn int
 		nn, err = blockingRead(fs, ih, off, p, intr)
@@ -276,11 +276,11 @@ func (me rootNode) Forget() {
 	me.fs.Destroy()
 }
 
-func (tfs *torrentFS) Root() (fusefs.Node, fuse.Error) {
+func (tfs *TorrentFS) Root() (fusefs.Node, fuse.Error) {
 	return rootNode{tfs}, nil
 }
 
-func (me *torrentFS) Destroy() {
+func (me *TorrentFS) Destroy() {
 	me.mu.Lock()
 	select {
 	case <-me.destroyed:
@@ -290,8 +290,8 @@ func (me *torrentFS) Destroy() {
 	me.mu.Unlock()
 }
 
-func New(cl *torrent.Client) *torrentFS {
-	fs := &torrentFS{
+func New(cl *torrent.Client) *TorrentFS {
+	fs := &TorrentFS{
 		Client:    cl,
 		destroyed: make(chan struct{}),
 	}
-- 
2.48.1