From 6affb9d7b137fc93d86c926a5587e77b8bc64255 Mon Sep 17 00:00:00 2001 From: Ross Zwisler Date: Tue, 24 Jan 2017 15:17:51 -0800 Subject: dax: fix build warnings with FS_DAX and !FS_IOMAP As reported by Arnd: https://lkml.org/lkml/2017/1/10/756 Compiling with the following configuration: # CONFIG_EXT2_FS is not set # CONFIG_EXT4_FS is not set # CONFIG_XFS_FS is not set # CONFIG_FS_IOMAP depends on the above filesystems, as is not set CONFIG_FS_DAX=y generates build warnings about unused functions in fs/dax.c: fs/dax.c:878:12: warning: `dax_insert_mapping' defined but not used [-Wunused-function] static int dax_insert_mapping(struct address_space *mapping, ^~~~~~~~~~~~~~~~~~ fs/dax.c:572:12: warning: `copy_user_dax' defined but not used [-Wunused-function] static int copy_user_dax(struct block_device *bdev, sector_t sector, size_t size, ^~~~~~~~~~~~~ fs/dax.c:542:12: warning: `dax_load_hole' defined but not used [-Wunused-function] static int dax_load_hole(struct address_space *mapping, void **entry, ^~~~~~~~~~~~~ fs/dax.c:312:14: warning: `grab_mapping_entry' defined but not used [-Wunused-function] static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index, ^~~~~~~~~~~~~~~~~~ Now that the struct buffer_head based DAX fault paths and I/O path have been removed we really depend on iomap support being present for DAX. Make this explicit by selecting FS_IOMAP if we compile in DAX support. This allows us to remove conditional selections of FS_IOMAP when FS_DAX was present for ext2 and ext4, and to remove an #ifdef in fs/dax.c. Link: http://lkml.kernel.org/r/1484087383-29478-1-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler Reported-by: Arnd Bergmann Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/Kconfig') diff --git a/fs/Kconfig b/fs/Kconfig index c2a377cdda2b..83eab52fb3f6 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -38,6 +38,7 @@ config FS_DAX bool "Direct Access (DAX) support" depends on MMU depends on !(ARM || MIPS || SPARC) + select FS_IOMAP help Direct Access (DAX) can be used on memory-backed block devices. If the block device supports DAX and the filesystem supports DAX, -- cgit v1.2.3