.

wcfs/misc.go

@@ -346,6 +346,7 @@ func (f *skFile) Read(dest []byte, /*ignored*/off int64) (fuse.ReadResult, fuse.
 	}
 	if err == io.EOF {
 		n = 0 // read(2): "zero indicates end of file"
+		err = nil
 	}
 	if err != nil {
 		return nil, err2LogStatus(err)

wcfs/wcfs.go

@@ -1446,8 +1446,8 @@ func (wnode *WatchNode) Open(flags uint32, fctx *fuse.Context) (nodefs.File, fus
 // wcfs initiated requests.
 func (wlink *WatchLink) serveRX() {
 	err := wlink._serveRX()
-	_ = err
 	// XXX log error if !close
+	log.Error(err)
 	// XXX locking
 	delete(wlink.head.wlinkTab, wlink)
 }
@@ -1470,8 +1470,8 @@ func (wlink *WatchLink) _serveRX() (err error) {
 		}
 	}()
 
-	// close .sk on error/wcfs stopping or return. closing .sk wakes up rx on it.
-	// make sure to stop wg on error return.
+	// close .sk on error/wcfs stopping or return. closing .sk wakes up rx
+	// on it and rx on client side. make sure to stop wg on error return.
 	retq := make(chan struct{})
 	defer close(retq)
 	wg.Go(func() error {
@@ -1504,7 +1504,7 @@ func (wlink *WatchLink) _serveRX() (err error) {
 
 		stream, msg, err := parseWatchFrame(l)
 		if err != nil {
-			return fmt.Errorf("%s", err)
+			return err
 		}
 
 		// reply from client to wcfs
@@ -1522,7 +1522,14 @@ func (wlink *WatchLink) _serveRX() (err error) {
 			continue
 		}
 
-		// client-initiated watch request
+		// client-initiated request
+
+		// bye		TODO document in "Invalidation protocol"
+		if msg == "bye" {
+			return nil // deferred sk.Close will wake-up rx on client side
+		}
+
+		// watch ...
 		if atomic.LoadInt32(&handlingWatch) != 0 {
 			return fmt.Errorf("%d: another watch request is already in progress", stream)
 		}

wcfs/wcfs_test.py

@@ -372,19 +372,14 @@ class tWatch:
 
         # python/stdio lock file object on read/write
         # however we need both read and write to be working simultaneously.
-        # fdopen takes ownership of file descriptor and closes it when file object is closed.
+        #
+        # fdopen takes ownership of file descriptor and closes it when file
+        # object is closed -> we dup fd so that each file object has its own fd.
 
-        #print('\n\n')
-        #os.system("ls -l %s" % tdb.path("head"))
-        #print('\n\n')
-        #os.system("LANG=C strace stat %s" % tdb.path("head/watch"))
-        #print('\n\n')
-        #os.system("LANG=C strace cat %s" % tdb.path("head/watch"))
-        #print('\n\n')
-
-        t.wh  = os.open(tdb.path("head/watch"), os.O_RDWR)
-        t.wrx = os.fdopen(t.wh, 'rb')
-        t.wtx = os.fdopen(t.wh, 'wb')
+        wh  = os.open(tdb.path("head/watch"), os.O_RDWR)
+        wh2 = os.dup(wh)    # XXX temp?
+        t.wrx = os.fdopen(wh, 'rb')
+        t.wtx = os.fdopen(wh2, 'wb')
 
         t._acceptq  = chan() # (stream, msg)    server originated messages go here
         t._rxmu     = threading.Lock()
@@ -400,8 +395,12 @@ class tWatch:
 
     def close(t):
         t.tdb._tracked.remove(t)
-        os.close(t.wh)
+        t._send(1, b'bye')  # ask wcfs to close its tx & rx sides; close(wcfs.tx) wakes up _serveRecv
         t._serveDone.recv()
+
+        t.wtx.close()
+        t.wrx.close()
+
         # wakeup everyone waiting for rx
         t._acceptq.close()
         with t._rxmu: