@@ -24,15 +24,6 @@ static inline struct inode *bdev_file_inode(struct file *file)
return file->f_mapping->host;
}
-static int blkdev_get_block(struct inode *inode, sector_t iblock,
- struct buffer_head *bh, int create)
-{
- bh->b_bdev = I_BDEV(inode);
- bh->b_blocknr = iblock;
- set_buffer_mapped(bh);
- return 0;
-}
-
static blk_opf_t dio_bio_write_op(struct kiocb *iocb)
{
blk_opf_t opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
@@ -400,7 +391,8 @@ static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
iomap->type = IOMAP_MAPPED;
iomap->addr = iomap->offset;
iomap->length = isize - iomap->offset;
- iomap->flags |= IOMAP_F_BUFFER_HEAD;
+ if (IS_ENABLED(CONFIG_BUFFER_HEAD))
+ iomap->flags |= IOMAP_F_BUFFER_HEAD;
return 0;
}
@@ -408,6 +400,16 @@ static const struct iomap_ops blkdev_iomap_ops = {
.iomap_begin = blkdev_iomap_begin,
};
+#ifdef CONFIG_BUFFER_HEAD
+static int blkdev_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh, int create)
+{
+ bh->b_bdev = I_BDEV(inode);
+ bh->b_blocknr = iblock;
+ set_buffer_mapped(bh);
+ return 0;
+}
+
static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, blkdev_get_block, wbc);
@@ -453,6 +455,55 @@ const struct address_space_operations def_blk_aops = {
.migrate_folio = buffer_migrate_folio_norefs,
.is_dirty_writeback = buffer_check_dirty_writeback,
};
+#else /* CONFIG_BUFFER_HEAD */
+static int blkdev_read_folio(struct file *file, struct folio *folio)
+{
+ return iomap_read_folio(folio, &blkdev_iomap_ops);
+}
+
+static void blkdev_readahead(struct readahead_control *rac)
+{
+ iomap_readahead(rac, &blkdev_iomap_ops);
+}
+
+static int blkdev_map_blocks(struct iomap_writepage_ctx *wpc,
+ struct inode *inode, loff_t offset)
+{
+ loff_t isize = i_size_read(inode);
+
+ if (WARN_ON_ONCE(offset >= isize))
+ return -EIO;
+ if (offset >= wpc->iomap.offset &&
+ offset < wpc->iomap.offset + wpc->iomap.length)
+ return 0;
+ return blkdev_iomap_begin(inode, offset, isize - offset,
+ IOMAP_WRITE, &wpc->iomap, NULL);
+}
+
+static const struct iomap_writeback_ops blkdev_writeback_ops = {
+ .map_blocks = blkdev_map_blocks,
+};
+
+static int blkdev_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct iomap_writepage_ctx wpc = { };
+
+ return iomap_writepages(mapping, wbc, &wpc, &blkdev_writeback_ops);
+}
+
+const struct address_space_operations def_blk_aops = {
+ .dirty_folio = filemap_dirty_folio,
+ .release_folio = iomap_release_folio,
+ .invalidate_folio = iomap_invalidate_folio,
+ .read_folio = blkdev_read_folio,
+ .readahead = blkdev_readahead,
+ .writepages = blkdev_writepages,
+ .is_partially_uptodate = iomap_is_partially_uptodate,
+ .error_remove_page = generic_error_remove_page,
+ .migrate_folio = filemap_migrate_folio,
+};
+#endif /* CONFIG_BUFFER_HEAD */
/*
* for a block special file file_inode(file)->i_size is zero
@@ -15,6 +15,7 @@ if MD
config BLK_DEV_MD
tristate "RAID support"
select BLOCK_HOLDER_DEPRECATED if SYSFS
+ select BUFFER_HEAD
# BLOCK_LEGACY_AUTOLOAD requirement should be removed
# after relevant mdadm enhancements - to make "names=yes"
# the default - are widely available.
@@ -18,8 +18,12 @@ config VALIDATE_FS_PARSER
config FS_IOMAP
bool
+config BUFFER_HEAD
+ bool
+
# old blockdev_direct_IO implementation. Use iomap for new code instead
config LEGACY_DIRECT_IO
+ depends on BUFFER_HEAD
bool
if BLOCK
@@ -17,7 +17,7 @@ obj-y := open.o read_write.o file_table.o super.o \
fs_types.o fs_context.o fs_parser.o fsopen.o init.o \
kernel_read_file.o mnt_idmapping.o remap_range.o
-obj-$(CONFIG_BLOCK) += buffer.o mpage.o
+obj-$(CONFIG_BUFFER_HEAD) += buffer.o mpage.o
obj-$(CONFIG_PROC_FS) += proc_namespace.o
obj-$(CONFIG_LEGACY_DIRECT_IO) += direct-io.o
obj-y += notify/
@@ -2,6 +2,7 @@
config ADFS_FS
tristate "ADFS file system support"
depends on BLOCK
+ select BUFFER_HEAD
help
The Acorn Disc Filing System is the standard file system of the
RiscOS operating system which runs on Acorn's ARM-based Risc PC
@@ -2,6 +2,7 @@
config AFFS_FS
tristate "Amiga FFS file system support"
depends on BLOCK
+ select BUFFER_HEAD
select LEGACY_DIRECT_IO
help
The Fast File System (FFS) is the common file system used on hard
@@ -2,6 +2,7 @@
config BEFS_FS
tristate "BeOS file system (BeFS) support (read only)"
depends on BLOCK
+ select BUFFER_HEAD
select NLS
help
The BeOS File System (BeFS) is the native file system of Be, Inc's
@@ -2,6 +2,7 @@
config BFS_FS
tristate "BFS file system support"
depends on BLOCK
+ select BUFFER_HEAD
help
Boot File System (BFS) is a file system used under SCO UnixWare to
allow the bootloader access to the kernel image and other important
@@ -2,6 +2,7 @@
config EFS_FS
tristate "EFS file system support (read only)"
depends on BLOCK
+ select BUFFER_HEAD
help
EFS is an older file system used for non-ISO9660 CD-ROMs and hard
disk partitions by SGI's IRIX operating system (IRIX 6.0 and newer
@@ -2,6 +2,7 @@
config EXFAT_FS
tristate "exFAT filesystem support"
+ select BUFFER_HEAD
select NLS
select LEGACY_DIRECT_IO
help
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config EXT2_FS
tristate "Second extended fs support"
+ select BUFFER_HEAD
select FS_IOMAP
select LEGACY_DIRECT_IO
help
@@ -28,6 +28,7 @@ config EXT3_FS_SECURITY
config EXT4_FS
tristate "The Extended 4 (ext4) filesystem"
+ select BUFFER_HEAD
select JBD2
select CRC16
select CRYPTO
@@ -2,6 +2,7 @@
config F2FS_FS
tristate "F2FS filesystem support"
depends on BLOCK
+ select BUFFER_HEAD
select NLS
select CRYPTO
select CRYPTO_CRC32
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config FAT_FS
tristate
+ select BUFFER_HEAD
select NLS
select LEGACY_DIRECT_IO
help
@@ -2,6 +2,7 @@
config VXFS_FS
tristate "FreeVxFS file system support (VERITAS VxFS(TM) compatible)"
depends on BLOCK
+ select BUFFER_HEAD
help
FreeVxFS is a file system driver that support the VERITAS VxFS(TM)
file system format. VERITAS VxFS(TM) is the standard file system
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config GFS2_FS
tristate "GFS2 file system support"
+ select BUFFER_HEAD
select FS_POSIX_ACL
select CRC32
select LIBCRC32C
@@ -2,6 +2,7 @@
config HFS_FS
tristate "Apple Macintosh file system support"
depends on BLOCK
+ select BUFFER_HEAD
select NLS
select LEGACY_DIRECT_IO
help
@@ -2,6 +2,7 @@
config HFSPLUS_FS
tristate "Apple Extended HFS file system support"
depends on BLOCK
+ select BUFFER_HEAD
select NLS
select NLS_UTF8
select LEGACY_DIRECT_IO
@@ -2,6 +2,7 @@
config HPFS_FS
tristate "OS/2 HPFS file system support"
depends on BLOCK
+ select BUFFER_HEAD
select FS_IOMAP
help
OS/2 is IBM's operating system for PC's, the same as Warp, and HPFS
@@ -41,6 +41,12 @@ static inline struct iomap_page *to_iomap_page(struct folio *folio)
return NULL;
}
+static inline bool iomap_use_buffer_heads(const struct iomap *iomap)
+{
+ return IS_ENABLED(CONFIG_BUFFER_HEAD) &&
+ (iomap->flags & IOMAP_F_BUFFER_HEAD);
+}
+
static struct bio_set iomap_ioend_bioset;
static struct iomap_page *
@@ -675,7 +681,7 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos,
if (srcmap->type == IOMAP_INLINE)
status = iomap_write_begin_inline(iter, folio);
- else if (srcmap->flags & IOMAP_F_BUFFER_HEAD)
+ else if (iomap_use_buffer_heads(srcmap))
status = __block_write_begin_int(folio, pos, len, NULL, srcmap);
else
status = __iomap_write_begin(iter, pos, len, folio);
@@ -745,7 +751,7 @@ static size_t iomap_write_end(struct iomap_iter *iter, loff_t pos, size_t len,
if (srcmap->type == IOMAP_INLINE) {
ret = iomap_write_end_inline(iter, folio, pos, copied);
- } else if (srcmap->flags & IOMAP_F_BUFFER_HEAD) {
+ } else if (iomap_use_buffer_heads(srcmap)) {
ret = block_write_end(NULL, iter->inode->i_mapping, pos, len,
copied, &folio->page, NULL);
} else {
@@ -1248,7 +1254,7 @@ static loff_t iomap_folio_mkwrite_iter(struct iomap_iter *iter,
loff_t length = iomap_length(iter);
int ret;
- if (iter->iomap.flags & IOMAP_F_BUFFER_HEAD) {
+ if (iomap_use_buffer_heads(&iter->iomap)) {
ret = __block_write_begin_int(folio, iter->pos, length, NULL,
&iter->iomap);
if (ret)
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config ISO9660_FS
tristate "ISO 9660 CDROM file system support"
+ select BUFFER_HEAD
help
This is the standard file system used on CD-ROMs. It was previously
known as "High Sierra File System" and is called "hsfs" on other
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config JFS_FS
tristate "JFS filesystem support"
+ select BUFFER_HEAD
select NLS
select CRC32
select LEGACY_DIRECT_IO
@@ -2,6 +2,7 @@
config MINIX_FS
tristate "Minix file system support"
depends on BLOCK
+ select BUFFER_HEAD
help
Minix is a simple operating system used in many classes about OS's.
The minix file system (method to organize files on a hard disk
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config NILFS2_FS
tristate "NILFS2 file system support"
+ select BUFFER_HEAD
select CRC32
select LEGACY_DIRECT_IO
help
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config NTFS_FS
tristate "NTFS file system support"
+ select BUFFER_HEAD
select NLS
help
NTFS is the file system of Microsoft Windows NT, 2000, XP and 2003.
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config NTFS3_FS
tristate "NTFS Read-Write file system support"
+ select BUFFER_HEAD
select NLS
select LEGACY_DIRECT_IO
help
@@ -2,6 +2,7 @@
config OCFS2_FS
tristate "OCFS2 file system support"
depends on INET && SYSFS && CONFIGFS_FS
+ select BUFFER_HEAD
select JBD2
select CRC32
select QUOTA
@@ -2,6 +2,7 @@
config OMFS_FS
tristate "SonicBlue Optimized MPEG File System support"
depends on BLOCK
+ select BUFFER_HEAD
select CRC_ITU_T
help
This is the proprietary file system used by the Rio Karma music
@@ -2,6 +2,7 @@
config QNX4FS_FS
tristate "QNX4 file system support (read only)"
depends on BLOCK
+ select BUFFER_HEAD
help
This is the file system used by the real-time operating systems
QNX 4 and QNX 6 (the latter is also called QNX RTP).
@@ -2,6 +2,7 @@
config QNX6FS_FS
tristate "QNX6 file system support (read only)"
depends on BLOCK && CRC32
+ select BUFFER_HEAD
help
This is the file system used by the real-time operating systems
QNX 6 (also called QNX RTP).
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config REISERFS_FS
tristate "Reiserfs support (deprecated)"
+ select BUFFER_HEAD
select CRC32
select LEGACY_DIRECT_IO
help
@@ -2,6 +2,7 @@
config SYSV_FS
tristate "System V/Xenix/V7/Coherent file system support"
depends on BLOCK
+ select BUFFER_HEAD
help
SCO, Xenix and Coherent are commercial Unix systems for Intel
machines, and Version 7 was used on the DEC PDP-11. Saying Y
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
config UDF_FS
tristate "UDF file system support"
+ select BUFFER_HEAD
select CRC_ITU_T
select NLS
select LEGACY_DIRECT_IO
@@ -2,6 +2,7 @@
config UFS_FS
tristate "UFS file system support (read only)"
depends on BLOCK
+ select BUFFER_HEAD
help
BSD and derivate versions of Unix (such as SunOS, FreeBSD, NetBSD,
OpenBSD and NeXTstep) use a file system called UFS. Some System V
@@ -16,8 +16,6 @@
#include <linux/wait.h>
#include <linux/atomic.h>
-#ifdef CONFIG_BLOCK
-
enum bh_state_bits {
BH_Uptodate, /* Contains valid data */
BH_Dirty, /* Is dirty */
@@ -198,7 +196,6 @@ void set_bh_page(struct buffer_head *bh,
struct page *page, unsigned long offset);
void folio_set_bh(struct buffer_head *bh, struct folio *folio,
unsigned long offset);
-bool try_to_free_buffers(struct folio *);
struct buffer_head *folio_alloc_buffers(struct folio *folio, unsigned long size,
bool retry);
struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
@@ -213,10 +210,6 @@ void end_buffer_async_write(struct buffer_head *bh, int uptodate);
/* Things to do with buffers at mapping->private_list */
void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode);
-int inode_has_buffers(struct inode *);
-void invalidate_inode_buffers(struct inode *);
-int remove_inode_buffers(struct inode *inode);
-int sync_mapping_buffers(struct address_space *mapping);
int generic_buffers_fsync_noflush(struct file *file, loff_t start, loff_t end,
bool datasync);
int generic_buffers_fsync(struct file *file, loff_t start, loff_t end,
@@ -240,9 +233,6 @@ void __bforget(struct buffer_head *);
void __breadahead(struct block_device *, sector_t block, unsigned int size);
struct buffer_head *__bread_gfp(struct block_device *,
sector_t block, unsigned size, gfp_t gfp);
-void invalidate_bh_lrus(void);
-void invalidate_bh_lrus_cpu(void);
-bool has_bh_in_lru(int cpu, void *dummy);
struct buffer_head *alloc_buffer_head(gfp_t gfp_flags);
void free_buffer_head(struct buffer_head * bh);
void unlock_buffer(struct buffer_head *bh);
@@ -258,8 +248,6 @@ int __bh_read(struct buffer_head *bh, blk_opf_t op_flags, bool wait);
void __bh_read_batch(int nr, struct buffer_head *bhs[],
blk_opf_t op_flags, bool force_lock);
-extern int buffer_heads_over_limit;
-
/*
* Generic address_space_operations implementations for buffer_head-backed
* address_spaces.
@@ -304,8 +292,6 @@ extern int buffer_migrate_folio_norefs(struct address_space *,
#define buffer_migrate_folio_norefs NULL
#endif
-void buffer_init(void);
-
/*
* inline definitions
*/
@@ -465,7 +451,20 @@ __bread(struct block_device *bdev, sector_t block, unsigned size)
bool block_dirty_folio(struct address_space *mapping, struct folio *folio);
-#else /* CONFIG_BLOCK */
+#ifdef CONFIG_BUFFER_HEAD
+
+void buffer_init(void);
+bool try_to_free_buffers(struct folio *folio);
+int inode_has_buffers(struct inode *inode);
+void invalidate_inode_buffers(struct inode *inode);
+int remove_inode_buffers(struct inode *inode);
+int sync_mapping_buffers(struct address_space *mapping);
+void invalidate_bh_lrus(void);
+void invalidate_bh_lrus_cpu(void);
+bool has_bh_in_lru(int cpu, void *dummy);
+extern int buffer_heads_over_limit;
+
+#else /* CONFIG_BUFFER_HEAD */
static inline void buffer_init(void) {}
static inline bool try_to_free_buffers(struct folio *folio) { return true; }
@@ -473,9 +472,10 @@ static inline int inode_has_buffers(struct inode *inode) { return 0; }
static inline void invalidate_inode_buffers(struct inode *inode) {}
static inline int remove_inode_buffers(struct inode *inode) { return 1; }
static inline int sync_mapping_buffers(struct address_space *mapping) { return 0; }
+static inline void invalidate_bh_lrus(void) {}
static inline void invalidate_bh_lrus_cpu(void) {}
static inline bool has_bh_in_lru(int cpu, void *dummy) { return false; }
#define buffer_heads_over_limit 0
-#endif /* CONFIG_BLOCK */
+#endif /* CONFIG_BUFFER_HEAD */
#endif /* _LINUX_BUFFER_HEAD_H */
@@ -12,6 +12,7 @@
#define RWBS_LEN 8
+#ifdef CONFIG_BUFFER_HEAD
DECLARE_EVENT_CLASS(block_buffer,
TP_PROTO(struct buffer_head *bh),
@@ -61,6 +62,7 @@ DEFINE_EVENT(block_buffer, block_dirty_buffer,
TP_ARGS(bh)
);
+#endif /* CONFIG_BUFFER_HEAD */
/**
* block_rq_requeue - place block IO request back on a queue
@@ -684,7 +684,7 @@ int migrate_folio(struct address_space *mapping, struct folio *dst,
}
EXPORT_SYMBOL(migrate_folio);
-#ifdef CONFIG_BLOCK
+#ifdef CONFIG_BUFFER_HEAD
/* Returns true if all buffers are successfully locked */
static bool buffer_migrate_lock_buffers(struct buffer_head *head,
enum migrate_mode mode)
@@ -837,7 +837,7 @@ int buffer_migrate_folio_norefs(struct address_space *mapping,
return __buffer_migrate_folio(mapping, dst, src, mode, true);
}
EXPORT_SYMBOL_GPL(buffer_migrate_folio_norefs);
-#endif
+#endif /* CONFIG_BUFFER_HEAD */
int filemap_migrate_folio(struct address_space *mapping,
struct folio *dst, struct folio *src, enum migrate_mode mode)
Add a new config option that controls building the buffer_head code, and select it from all file systems and stacking drivers that need it. For the block device nodes and alternative iomap based buffered I/O path is provided when buffer_head support is not enabled, and iomap needs a little tweak to be able to compile out the buffer_head based code path. Otherwise this is just Kconfig and ifdef changes. Signed-off-by: Christoph Hellwig <hch@lst.de> --- block/fops.c | 71 +++++++++++++++++++++++++++++++----- drivers/md/Kconfig | 1 + fs/Kconfig | 4 ++ fs/Makefile | 2 +- fs/adfs/Kconfig | 1 + fs/affs/Kconfig | 1 + fs/befs/Kconfig | 1 + fs/bfs/Kconfig | 1 + fs/efs/Kconfig | 1 + fs/exfat/Kconfig | 1 + fs/ext2/Kconfig | 1 + fs/ext4/Kconfig | 1 + fs/f2fs/Kconfig | 1 + fs/fat/Kconfig | 1 + fs/freevxfs/Kconfig | 1 + fs/gfs2/Kconfig | 1 + fs/hfs/Kconfig | 1 + fs/hfsplus/Kconfig | 1 + fs/hpfs/Kconfig | 1 + fs/iomap/buffered-io.c | 12 ++++-- fs/isofs/Kconfig | 1 + fs/jfs/Kconfig | 1 + fs/minix/Kconfig | 1 + fs/nilfs2/Kconfig | 1 + fs/ntfs/Kconfig | 1 + fs/ntfs3/Kconfig | 1 + fs/ocfs2/Kconfig | 1 + fs/omfs/Kconfig | 1 + fs/qnx4/Kconfig | 1 + fs/qnx6/Kconfig | 1 + fs/reiserfs/Kconfig | 1 + fs/sysv/Kconfig | 1 + fs/udf/Kconfig | 1 + fs/ufs/Kconfig | 1 + include/linux/buffer_head.h | 32 ++++++++-------- include/trace/events/block.h | 2 + mm/migrate.c | 4 +- 37 files changed, 125 insertions(+), 32 deletions(-)