Merge tag 'for-6.3/dio-2023-02-16' of git://git.kernel.dk/linux

Pull legacy dio update from Jens Axboe:
"We only have a few file systems that use the old dio code, make them
select it rather than build it unconditionally"

* tag 'for-6.3/dio-2023-02-16' of git://git.kernel.dk/linux:
fs: build the legacy direct I/O code conditionally
fs: move sb_init_dio_done_wq out of direct-io.c

fs/Kconfig

···
 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"

fs/Makefile

···
 		kernel_read_file.o mnt_idmapping.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

fs/affs/Kconfig

···
 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

fs/direct-io.c

···
 	return ret;
 }
 
-/*
- * Create workqueue for deferred direct IO completions. We allocate the
- * workqueue when it's first needed. This avoids creating workqueue for
- * filesystems that don't need it and also allows us to create the workqueue
- * late enough so the we can include s_id in the name of the workqueue.
- */
-int sb_init_dio_done_wq(struct super_block *sb)
-{
-	struct workqueue_struct *old;
-	struct workqueue_struct *wq = alloc_workqueue("dio/%s",
-						      WQ_MEM_RECLAIM, 0,
-						      sb->s_id);
-	if (!wq)
-		return -ENOMEM;
-	/*
-	 * This has to be atomic as more DIOs can race to create the workqueue
-	 */
-	old = cmpxchg(&sb->s_dio_done_wq, NULL, wq);
-	/* Someone created workqueue before us? Free ours... */
-	if (old)
-		destroy_workqueue(wq);
-	return 0;
-}
-
 static int dio_set_defer_completion(struct dio *dio)
 {
 	struct super_block *sb = dio->inode->i_sb;

fs/exfat/Kconfig

···
 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.

fs/ext2/Kconfig

···
 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.
 

fs/fat/Kconfig

···
 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

fs/hfs/Kconfig

···
 	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.

fs/hfsplus/Kconfig

···
 	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.

fs/internal.h

···
 struct super_block *user_get_super(dev_t, bool excl);
 void put_super(struct super_block *sb);
 extern bool mount_capable(struct fs_context *);
+int sb_init_dio_done_wq(struct super_block *sb);
 
 /*
  * open.c
···
  * fs/nsfs.c
  */
 extern const struct dentry_operations ns_dentry_operations;
-
-/* direct-io.c: */
-int sb_init_dio_done_wq(struct super_block *sb);
 
 /*
  * fs/stat.c:

fs/jfs/Kconfig

···
 	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>.

fs/nilfs2/Kconfig

···
 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

fs/ntfs3/Kconfig

···
 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.
 

fs/ocfs2/Kconfig

···
 	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

fs/reiserfs/Kconfig

···
 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

fs/super.c

···
 	return thaw_super_locked(sb);
 }
 EXPORT_SYMBOL(thaw_super);
+
+/*
+ * Create workqueue for deferred direct IO completions. We allocate the
+ * workqueue when it's first needed. This avoids creating workqueue for
+ * filesystems that don't need it and also allows us to create the workqueue
+ * late enough so the we can include s_id in the name of the workqueue.
+ */
+int sb_init_dio_done_wq(struct super_block *sb)
+{
+	struct workqueue_struct *old;
+	struct workqueue_struct *wq = alloc_workqueue("dio/%s",
+						      WQ_MEM_RECLAIM, 0,
+						      sb->s_id);
+	if (!wq)
+		return -ENOMEM;
+	/*
+	 * This has to be atomic as more DIOs can race to create the workqueue
+	 */
+	old = cmpxchg(&sb->s_dio_done_wq, NULL, wq);
+	/* Someone created workqueue before us? Free ours... */
+	if (old)
+		destroy_workqueue(wq);
+	return 0;
+}

fs/udf/Kconfig

···
 	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