fix deadlock

cluster.go

@@ -74,6 +74,7 @@ type Cluster struct {
 	cancelKeepalive context.CancelFunc
 	downloadMux     sync.Mutex
 	downloading     map[string]chan error
+	fileMux         sync.RWMutex
 	fileset         map[string]int64
 
 	client   *http.Client
@@ -402,8 +403,8 @@ func (cr *Cluster) Disabled() <-chan struct{} {
 }
 
 func (cr *Cluster) CachedFileSize(hash string) (size int64, ok bool) {
-	cr.mux.RLock()
-	defer cr.mux.RUnlock()
+	cr.fileMux.RLock()
+	defer cr.fileMux.RUnlock()
 	size, ok = cr.fileset[hash]
 	return
 }
@@ -544,10 +545,10 @@ func (cr *Cluster) SyncFiles(ctx context.Context, files []FileInfo, heavyCheck b
 	for _, f := range files {
 		fileset[f.Hash] = f.Size
 	}
-	cr.mux.Lock()
+	cr.fileMux.Lock()
 	cr.fileset = fileset
 	cr.issync.Store(false)
-	cr.mux.Unlock()
+	cr.fileMux.Unlock()
 
 	go cr.gc()
 }
@@ -959,8 +960,8 @@ func (cr *Cluster) DownloadFile(ctx context.Context, hash string) (err error) {
 		}
 	}
 
-	cr.mux.Lock()
+	cr.fileMux.Lock()
 	cr.fileset[hash] = size
-	cr.mux.Unlock()
+	cr.fileMux.Unlock()
 	return
 }

handler.go

@@ -208,13 +208,15 @@ func (cr *Cluster) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 			http.Error(rw, "404 Not Found", http.StatusNotFound)
 			return
 		}
+		logDebugf("Serving download %s", hash)
 
 		query := req.URL.Query()
 		if !checkQuerySign(hash, cr.password, query) {
 			http.Error(rw, "Cannot verify signature", http.StatusForbidden)
 			return
 		}
 
+		logDebugf("Handling download %s", hash)
 		cr.handleDownload(rw, req, hash)
 		return
 	case strings.HasPrefix(rawpath, "/measure/"):
@@ -281,7 +283,9 @@ func (cr *Cluster) handleDownload(rw http.ResponseWriter, req *http.Request, has
 
 	var err error
 	// check if file was indexed in the fileset
+	logDebugf("Getting cached file size for %s", hash)
 	size, ok := cr.CachedFileSize(hash)
+	logDebugf("Cached file size for %s is %d", hash, size)
 	if !ok {
 		logInfof("Downloading %s", hash)
 		if err := cr.DownloadFile(req.Context(), hash); err != nil {

storage_mount.go

@@ -183,6 +183,7 @@ func (s *MountStorage) ServeDownload(rw http.ResponseWriter, req *http.Request,
 				}
 				s.lastCheck = now
 				s.checkMux.Unlock()
+
 				tctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
 				defer cancel()
 				if supportRange, err := s.checkAlive(tctx, 0); err == nil {