[PATCH 2/2] fs: build the legacy direct I/O code conditionally

From: Christoph Hellwig
Date: Wed Jan 25 2023 - 01:58:56 EST

Add a new LEGACY_DIRECT_IO config symbol that is only selected by the
file systems that still use the legacy blockdev_direct_IO code, so that
kernels without support for those file systems don't need to build the
code.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/Kconfig | 4 ++++
fs/Makefile | 3 ++-
fs/affs/Kconfig | 1 +
fs/exfat/Kconfig | 1 +
fs/ext2/Kconfig | 1 +
fs/fat/Kconfig | 1 +
fs/hfs/Kconfig | 1 +
fs/hfsplus/Kconfig | 1 +
fs/jfs/Kconfig | 1 +
fs/nilfs2/Kconfig | 1 +
fs/ntfs3/Kconfig | 1 +
fs/ocfs2/Kconfig | 1 +
fs/reiserfs/Kconfig | 1 +
fs/udf/Kconfig | 1 +
14 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/fs/Kconfig b/fs/Kconfig
index 2685a4d0d35318..e99830c650336a 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -18,6 +18,10 @@ config VALIDATE_FS_PARSER
config FS_IOMAP
bool

+# old blockdev_direct_IO implementation. Use iomap for new code instead
+config LEGACY_DIRECT_IO
+ bool
+
if BLOCK

source "fs/ext2/Kconfig"
diff --git a/fs/Makefile b/fs/Makefile
index 4dea17840761a0..606c029e1c9bc3 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -19,13 +19,14 @@ obj-y := open.o read_write.o file_table.o super.o \
kernel_read_file.o remap_range.o

ifeq ($(CONFIG_BLOCK),y)
-obj-y += buffer.o direct-io.o mpage.o
+obj-y += buffer.o mpage.o
else
obj-y += no-block.o
endif

obj-$(CONFIG_PROC_FS) += proc_namespace.o

+obj-$(CONFIG_LEGACY_DIRECT_IO) += direct-io.o
obj-y += notify/
obj-$(CONFIG_EPOLL) += eventpoll.o
obj-y += anon_inodes.o
diff --git a/fs/affs/Kconfig b/fs/affs/Kconfig
index eb9d0ab850cb1d..962b86374e1c15 100644
--- a/fs/affs/Kconfig
+++ b/fs/affs/Kconfig
@@ -2,6 +2,7 @@
config AFFS_FS
tristate "Amiga FFS file system support"
depends on BLOCK
+ select LEGACY_DIRECT_IO
help
The Fast File System (FFS) is the common file system used on hard
disks by Amiga(tm) systems since AmigaOS Version 1.3 (34.20). Say Y
diff --git a/fs/exfat/Kconfig b/fs/exfat/Kconfig
index 5a65071b5ecf10..147edeb044691d 100644
--- a/fs/exfat/Kconfig
+++ b/fs/exfat/Kconfig
@@ -3,6 +3,7 @@
config EXFAT_FS
tristate "exFAT filesystem support"
select NLS
+ select LEGACY_DIRECT_IO
help
This allows you to mount devices formatted with the exFAT file system.
exFAT is typically used on SD-Cards or USB sticks.
diff --git a/fs/ext2/Kconfig b/fs/ext2/Kconfig
index 1248ff4ef56254..77393fda99af09 100644
--- a/fs/ext2/Kconfig
+++ b/fs/ext2/Kconfig
@@ -2,6 +2,7 @@
config EXT2_FS
tristate "Second extended fs support"
select FS_IOMAP
+ select LEGACY_DIRECT_IO
help
Ext2 is a standard Linux file system for hard disks.

diff --git a/fs/fat/Kconfig b/fs/fat/Kconfig
index 238cc55f84c429..afe83b4e717280 100644
--- a/fs/fat/Kconfig
+++ b/fs/fat/Kconfig
@@ -2,6 +2,7 @@
config FAT_FS
tristate
select NLS
+ select LEGACY_DIRECT_IO
help
If you want to use one of the FAT-based file systems (the MS-DOS and
VFAT (Windows 95) file systems), then you must say Y or M here
diff --git a/fs/hfs/Kconfig b/fs/hfs/Kconfig
index 129926b5142d8f..d985066006d588 100644
--- a/fs/hfs/Kconfig
+++ b/fs/hfs/Kconfig
@@ -3,6 +3,7 @@ config HFS_FS
tristate "Apple Macintosh file system support"
depends on BLOCK
select NLS
+ select LEGACY_DIRECT_IO
help
If you say Y here, you will be able to mount Macintosh-formatted
floppy disks and hard drive partitions with full read-write access.
diff --git a/fs/hfsplus/Kconfig b/fs/hfsplus/Kconfig
index 7d4229aecec05b..8034e7827a690b 100644
--- a/fs/hfsplus/Kconfig
+++ b/fs/hfsplus/Kconfig
@@ -4,6 +4,7 @@ config HFSPLUS_FS
depends on BLOCK
select NLS
select NLS_UTF8
+ select LEGACY_DIRECT_IO
help
If you say Y here, you will be able to mount extended format
Macintosh-formatted hard drive partitions with full read-write access.
diff --git a/fs/jfs/Kconfig b/fs/jfs/Kconfig
index 05cb0e8e4382ee..51e856f0e4b8d6 100644
--- a/fs/jfs/Kconfig
+++ b/fs/jfs/Kconfig
@@ -3,6 +3,7 @@ config JFS_FS
tristate "JFS filesystem support"
select NLS
select CRC32
+ select LEGACY_DIRECT_IO
help
This is a port of IBM's Journaled Filesystem . More information is
available in the file <file:Documentation/admin-guide/jfs.rst>.
diff --git a/fs/nilfs2/Kconfig b/fs/nilfs2/Kconfig
index 254d102e79c99b..7d59567465e121 100644
--- a/fs/nilfs2/Kconfig
+++ b/fs/nilfs2/Kconfig
@@ -2,6 +2,7 @@
config NILFS2_FS
tristate "NILFS2 file system support"
select CRC32
+ select LEGACY_DIRECT_IO
help
NILFS2 is a log-structured file system (LFS) supporting continuous
snapshotting. In addition to versioning capability of the entire
diff --git a/fs/ntfs3/Kconfig b/fs/ntfs3/Kconfig
index 6e4cbc48ab8e43..96cc236f7f7bd3 100644
--- a/fs/ntfs3/Kconfig
+++ b/fs/ntfs3/Kconfig
@@ -2,6 +2,7 @@
config NTFS3_FS
tristate "NTFS Read-Write file system support"
select NLS
+ select LEGACY_DIRECT_IO
help
Windows OS native file system (NTFS) support up to NTFS version 3.1.

diff --git a/fs/ocfs2/Kconfig b/fs/ocfs2/Kconfig
index 5d11380d872417..304d12186ccd38 100644
--- a/fs/ocfs2/Kconfig
+++ b/fs/ocfs2/Kconfig
@@ -7,6 +7,7 @@ config OCFS2_FS
select QUOTA
select QUOTA_TREE
select FS_POSIX_ACL
+ select LEGACY_DIRECT_IO
help
OCFS2 is a general purpose extent based shared disk cluster file
system with many similarities to ext3. It supports 64 bit inode
diff --git a/fs/reiserfs/Kconfig b/fs/reiserfs/Kconfig
index 33c8b0dd07a2e7..4d22ecfe0fab65 100644
--- a/fs/reiserfs/Kconfig
+++ b/fs/reiserfs/Kconfig
@@ -2,6 +2,7 @@
config REISERFS_FS
tristate "Reiserfs support (deprecated)"
select CRC32
+ select LEGACY_DIRECT_IO
help
Reiserfs is deprecated and scheduled to be removed from the kernel
in 2025. If you are still using it, please migrate to another
diff --git a/fs/udf/Kconfig b/fs/udf/Kconfig
index 26e1a49f3ba795..82e8bfa2dfd989 100644
--- a/fs/udf/Kconfig
+++ b/fs/udf/Kconfig
@@ -3,6 +3,7 @@ config UDF_FS
tristate "UDF file system support"
select CRC_ITU_T
select NLS
+ select LEGACY_DIRECT_IO
help
This is a file system used on some CD-ROMs and DVDs. Since the
file system is supported by multiple operating systems and is more
--
2.39.0