On Mon, Sep 20, 2021 at 03:13:15PM -0700, Bart Van Assche wrote: >> +#define wbc_blkcg_css(wbc) \ >> + ((wbc)->wb ? (wbc)->wb->blkcg_css : blkcg_root_css) >> +#else >> +#define wbc_blkcg_css(wbc) (blkcg_root_css) >> +#endif /* CONFIG_CGROUP_WRITEBACK */ > > This change may introduce annoying set-but-not-used warnings > with CONFIG_CGROUP_WRITEBACK=n. How about changing (blkcg_root_css) > into ((wbc), blkcg_root_css) to prevent this? I agree in principle, but in this case the caller pretty much has to use wbc in other ways, so I don't think it matters much.
