avoid closing chunkSaveErrChan too early

weed/filesys/filehandle.go

@@ -183,11 +183,10 @@ func (fh *FileHandle) Release(ctx context.Context, req *fuse.ReleaseRequest) err
 	}
 
 	if fh.f.isOpen == 0 {
+
 		if err := fh.doFlush(ctx, req.Header); err != nil {
 			glog.Errorf("Release doFlush %s: %v", fh.f.Name, err)
 		}
-		fh.f.wfs.ReleaseHandle(fh.f.fullpath(), fuse.HandleID(fh.handle))
-	}
 
 		// stop the goroutine
 		if !fh.dirtyPages.chunkSaveErrChanClosed {
@@ -195,6 +194,10 @@ func (fh *FileHandle) Release(ctx context.Context, req *fuse.ReleaseRequest) err
 			close(fh.dirtyPages.chunkSaveErrChan)
 		}
 
+		fh.f.wfs.ReleaseHandle(fh.f.fullpath(), fuse.HandleID(fh.handle))
+	}
+
+
 	return nil
 }