reproduce (this is a W=1 build):
        # https://github.com/smfrench/smb3-kernel/commit/7ad4ba8846086dd14f26bed6dd56de6d0050dfb4
        git remote add smfrench-smb3 https://github.com/smfrench/smb3-kernel.git
        git fetch --no-tags smfrench-smb3 pr/255
        git checkout 7ad4ba8846086dd14f26bed6dd56de6d0050dfb4

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/smb/