On Thu, Jul 20, 2023 at 03:45:11PM +0100, Matthew Wilcox wrote: > On Thu, Jul 20, 2023 at 04:04:52PM +0200, Christoph Hellwig wrote: > > @@ -400,7 +391,8 @@ static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > > iomap->type = IOMAP_MAPPED; > > iomap->addr = iomap->offset; > > iomap->length = isize - iomap->offset; > > - iomap->flags |= IOMAP_F_BUFFER_HEAD; > > + if (IS_ENABLED(CONFIG_BUFFER_HEAD)) > > + iomap->flags |= IOMAP_F_BUFFER_HEAD; > > Wouldn't it be simpler to do ... > > +#ifdef CONFIG_BUFFER_HEAD > #define IOMAP_F_BUFFER_HEAD (1U << 4) > +#else > +#define IOMAP_F_BUFFER_HEAD 0 > +#endif > > in include/linux/iomap.h ? > ... because this function then goes away. I guess we could do that. It is less intrusive, but I have to say I find flags that get defined away to 0 fairly confusing for the reader.
