On Tue, Apr 12, 2016 at 02:39:29PM -0600, Toshi Kani wrote: > To support DAX pmd mappings with unmodified applications, > filesystems need to align an mmap address by the pmd size. > @@ -708,6 +708,9 @@ const struct file_operations ext4_file_operations = { > .open = ext4_file_open, > .release = ext4_release_file, > .fsync = ext4_sync_file, > +#ifdef CONFIG_FS_DAX > + .get_unmapped_area = dax_get_unmapped_area, > +#endif > .splice_read = generic_file_splice_read, > .splice_write = iter_file_splice_write, > .fallocate = ext4_fallocate, Could you do something like: #ifdef CONFIG_FS_DAX struct page *read_dax_sector(struct block_device *bdev, sector_t n); +unsigned long dax_get_unmapped_area(struct file *filp, unsigned long addr, + unsigned long len, unsigned long pgoff, unsigned long flags); #else static inline struct page *read_dax_sector(struct block_device *bdev, sector_t n) { return ERR_PTR(-ENXIO); } +#define dax_get_unmapped_area NULL #endif in patch 1/5. Then there's no need for the ifdefs in each filesystem. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html