Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > On Fri, May 19, 2023 at 08:40:20AM +0100, David Howells wrote: > > +#ifdef CONFIG_FS_DAX > > + if (IS_DAX(in->f_mapping->host)) > > No need for the ifdef. IS_DAX is compile-time false if CONFIG_FS_DAX > is not set. Ah - it's not that IS_DAX() is conditionalised, it's that S_DAX is. There's a bunch of places that use CONFIG_FS_DAX blocks, but I guess that's because they include calls to functions that are conditionalised out. I wonder if the dax_iomap_rw() declaration in the header can have a non-DAX fallback that returns an error and then we can get rid of some of the other conditionalisation. David
