Fixes inotify not notifying on deletion of open files.

inotify.go

@@ -303,12 +303,16 @@ func (e *Event) ignoreLinux(mask uint32) bool {
 		return true
 	}
 
-	// If the event is not a DELETE or RENAME, the file must exist.
+	// If the event is MODIFY or CREATE, the file must exist.
 	// Otherwise the event is ignored.
 	// *Note*: this was put in place because it was seen that a MODIFY
 	// event was sent after the DELETE. This ignores that MODIFY and
 	// assumes a DELETE will come or has come if the file doesn't exist.
-	if !(e.Op&Remove == Remove || e.Op&Rename == Rename) {
+	// A CHMOD event (triggered by IN_MODIFY) can arrive when an open file is
+	// deleted.  In that case the DELETE event is deferred until all open
+	// handles for the file are closed. See
+	// https://github.com/fsnotify/fsnotify/issues/194 for more information.
+	if e.Op&Create == Create || e.Op&Write == Write {
 		_, statErr := os.Lstat(e.Name)
 		return os.IsNotExist(statErr)
 	}

inotify_test.go

@@ -447,3 +447,63 @@ func TestInotifyOverflow(t *testing.T) {
 			numDirs*numFiles, creates)
 	}
 }
+
+func TestInotifyDeleteOpenFile(t *testing.T) {
+	testDir := tempMkdir(t)
+	defer os.RemoveAll(testDir)
+
+	testFile := filepath.Join(testDir, "testfile")
+
+	handle, err := os.Create(testFile)
+	if err != nil {
+		t.Fatalf("Create failed: %v", err)
+	}
+
+	w, err := NewWatcher()
+	if err != nil {
+		t.Fatalf("Failed to create watcher: %v", err)
+	}
+	defer w.Close()
+
+	err = w.Add(testFile)
+	if err != nil {
+		t.Fatalf("Failed to add watch for %s: %v", testFile, err)
+	}
+
+	err = os.Remove(testFile)
+	if err != nil {
+		t.Fatalf("Failed to remove %s: %v", testFile, err)
+	}
+
+	var event Event
+
+	// Verify we receive Chmod event caused by the change in the file link count
+	// when we delete it.
+	select {
+	case event = <-w.Events:
+		if event.Op != Chmod {
+			t.Fatalf("Expected first event type %s, got: %v", Chmod, event.Op)
+		}
+	case <-time.After(100 * time.Millisecond):
+		t.Fatalf("Expected first event not delivered")
+	}
+
+	// Now close our open handle...
+	handle.Close()
+
+	// ...and observe the file being deleted from the disk.
+	select {
+	case event = <-w.Events:
+		if event.Op != Remove {
+			t.Fatalf("Expected second event type %s, got: %v", Remove, event.Op)
+		}
+	case <-time.After(100 * time.Millisecond):
+		t.Fatalf("Expected second event not delivered")
+	}
+
+	w.Close()
+
+	// Wait for the close to complete.
+	time.Sleep(50 * time.Millisecond)
+	isWatcherReallyClosed(t, w)
+}