An address_space will only have dax exceptional entries when FS_DAX is enabled. The current reliance on S_DAX causes compile failures when S_DAX is defined for DEV_DAX, but FS_DAX is disabled. Make dax_mapping() always return false so that mm/truncate.c drops its link time dependencies on fs/dax.c. Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: linux-fsdevel@xxxxxxxxxxxxxxx Cc: Christoph Hellwig <hch@xxxxxx> Cc: Jan Kara <jack@xxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx> Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap") Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> --- include/linux/dax.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/include/linux/dax.h b/include/linux/dax.h index 0185ecdae135..62e8cf7eb566 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -107,6 +107,10 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping, int __dax_zero_page_range(struct block_device *bdev, struct dax_device *dax_dev, sector_t sector, unsigned int offset, unsigned int length); +static inline bool dax_mapping(struct address_space *mapping) +{ + return mapping->host && IS_DAX(mapping->host); +} #else static inline int __dax_zero_page_range(struct block_device *bdev, struct dax_device *dax_dev, sector_t sector, @@ -114,12 +118,11 @@ static inline int __dax_zero_page_range(struct block_device *bdev, { return -ENXIO; } -#endif - static inline bool dax_mapping(struct address_space *mapping) { - return mapping->host && IS_DAX(mapping->host); + return false; } +#endif struct writeback_control; int dax_writeback_mapping_range(struct address_space *mapping,