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.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
diff --git a/fs/Kconfig b/fs/Kconfig
index c2a377c..83eab52 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -38,6 +38,7 @@
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,
diff --git a/fs/dax.c b/fs/dax.c
index 5c74f60..083b950 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -969,7 +969,6 @@
}
EXPORT_SYMBOL_GPL(__dax_zero_page_range);
-#ifdef CONFIG_FS_IOMAP
static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos)
{
return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9);
@@ -1407,4 +1406,3 @@
}
EXPORT_SYMBOL_GPL(dax_iomap_pmd_fault);
#endif /* CONFIG_FS_DAX_PMD */
-#endif /* CONFIG_FS_IOMAP */
diff --git a/fs/ext2/Kconfig b/fs/ext2/Kconfig
index 36bea5a..c634874e 100644
--- a/fs/ext2/Kconfig
+++ b/fs/ext2/Kconfig
@@ -1,6 +1,5 @@
config EXT2_FS
tristate "Second extended fs support"
- select FS_IOMAP if FS_DAX
help
Ext2 is a standard Linux file system for hard disks.
diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
index 7b90691..e38039f 100644
--- a/fs/ext4/Kconfig
+++ b/fs/ext4/Kconfig
@@ -37,7 +37,6 @@
select CRC16
select CRYPTO
select CRYPTO_CRC32C
- select FS_IOMAP if FS_DAX
help
This is the next generation of the ext3 filesystem.
