Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

12 files changed, 2757 insertions, 0 deletions

diff --git a/fs/adfs/Kconfig b/fs/adfs/Kconfig
new file mode 100644
index 000000000..1b97058f0
--- /dev/null
+++ b/fs/adfs/Kconfig
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0-only
+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
+	  systems and the Acorn Archimedes range of machines. If you say Y
+	  here, Linux will be able to read from ADFS partitions on hard drives
+	  and from ADFS-formatted floppy discs. If you also want to be able to
+	  write to those devices, say Y to "ADFS write support" below.
+
+	  The ADFS partition should be the first partition (i.e.,
+	  /dev/[hs]d?1) on each of your drives. Please read the file
+	  <file:Documentation/filesystems/adfs.rst> for further details.
+
+	  To compile this code as a module, choose M here: the module will be
+	  called adfs.
+
+	  If unsure, say N.
+
+config ADFS_FS_RW
+	bool "ADFS write support (DANGEROUS)"
+	depends on ADFS_FS
+	help
+	  If you say Y here, you will be able to write to ADFS partitions on
+	  hard drives and ADFS-formatted floppy disks. This is experimental
+	  codes, so if you're unsure, say N.
diff --git a/fs/adfs/Makefile b/fs/adfs/Makefile
new file mode 100644
index 000000000..cf7de6ece
--- /dev/null
+++ b/fs/adfs/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the linux adfs filesystem routines.
+#
+
+obj-$(CONFIG_ADFS_FS) += adfs.o
+
+adfs-objs := dir.o dir_f.o dir_fplus.o file.o inode.o map.o super.o
diff --git a/fs/adfs/adfs.h b/fs/adfs/adfs.h
new file mode 100644
index 000000000..0d32b7cd9
--- /dev/null
+++ b/fs/adfs/adfs.h
@@ -0,0 +1,230 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/adfs_fs.h>
+
+/* Internal data structures for ADFS */
+
+#define ADFS_FREE_FRAG		 0
+#define ADFS_BAD_FRAG		 1
+#define ADFS_ROOT_FRAG		 2
+
+#define ADFS_FILETYPE_NONE	((u16)~0)
+
+/* RISC OS 12-bit filetype is stored in load_address[19:8] */
+static inline u16 adfs_filetype(u32 loadaddr)
+{
+	return (loadaddr & 0xfff00000) == 0xfff00000 ?
+	       (loadaddr >> 8) & 0xfff : ADFS_FILETYPE_NONE;
+}
+
+#define ADFS_NDA_OWNER_READ	(1 << 0)
+#define ADFS_NDA_OWNER_WRITE	(1 << 1)
+#define ADFS_NDA_LOCKED		(1 << 2)
+#define ADFS_NDA_DIRECTORY	(1 << 3)
+#define ADFS_NDA_EXECUTE	(1 << 4)
+#define ADFS_NDA_PUBLIC_READ	(1 << 5)
+#define ADFS_NDA_PUBLIC_WRITE	(1 << 6)
+
+/*
+ * adfs file system inode data in memory
+ */
+struct adfs_inode_info {
+	loff_t		mmu_private;
+	__u32		parent_id;	/* parent indirect disc address	*/
+	__u32		indaddr;	/* object indirect disc address	*/
+	__u32		loadaddr;	/* RISC OS load address		*/
+	__u32		execaddr;	/* RISC OS exec address		*/
+	unsigned int	attr;		/* RISC OS permissions		*/
+	struct inode vfs_inode;
+};
+
+static inline struct adfs_inode_info *ADFS_I(struct inode *inode)
+{
+	return container_of(inode, struct adfs_inode_info, vfs_inode);
+}
+
+static inline bool adfs_inode_is_stamped(struct inode *inode)
+{
+	return (ADFS_I(inode)->loadaddr & 0xfff00000) == 0xfff00000;
+}
+
+/*
+ * Forward-declare this
+ */
+struct adfs_discmap;
+struct adfs_dir_ops;
+
+/*
+ * ADFS file system superblock data in memory
+ */
+struct adfs_sb_info {
+	union { struct {
+		struct adfs_discmap *s_map;	/* bh list containing map */
+		const struct adfs_dir_ops *s_dir; /* directory operations */
+		};
+		struct rcu_head rcu;	/* used only at shutdown time	 */
+	};
+	kuid_t		s_uid;		/* owner uid */
+	kgid_t		s_gid;		/* owner gid */
+	umode_t		s_owner_mask;	/* ADFS owner perm -> unix perm */
+	umode_t		s_other_mask;	/* ADFS other perm -> unix perm	*/
+	int		s_ftsuffix;	/* ,xyz hex filetype suffix option */
+
+	__u32		s_ids_per_zone;	/* max. no ids in one zone */
+	__u32		s_idlen;	/* length of ID in map */
+	__u32		s_map_size;	/* sector size of a map	*/
+	signed int	s_map2blk;	/* shift left by this for map->sector*/
+	unsigned int	s_log2sharesize;/* log2 share size */
+	unsigned int	s_namelen;	/* maximum number of characters in name	 */
+};
+
+static inline struct adfs_sb_info *ADFS_SB(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+/*
+ * Directory handling
+ */
+struct adfs_dir {
+	struct super_block	*sb;
+
+	int			nr_buffers;
+	struct buffer_head	*bh[4];
+	struct buffer_head	**bhs;
+
+	unsigned int		pos;
+	__u32			parent_id;
+
+	union {
+		struct adfs_dirheader	*dirhead;
+		struct adfs_bigdirheader *bighead;
+	};
+	union {
+		struct adfs_newdirtail	*newtail;
+		struct adfs_bigdirtail	*bigtail;
+	};
+};
+
+/*
+ * This is the overall maximum name length
+ */
+#define ADFS_MAX_NAME_LEN	(256 + 4) /* +4 for ,xyz hex filetype suffix */
+struct object_info {
+	__u32		parent_id;		/* parent object id	*/
+	__u32		indaddr;		/* indirect disc addr	*/
+	__u32		loadaddr;		/* load address		*/
+	__u32		execaddr;		/* execution address	*/
+	__u32		size;			/* size			*/
+	__u8		attr;			/* RISC OS attributes	*/
+	unsigned int	name_len;		/* name length		*/
+	char		name[ADFS_MAX_NAME_LEN];/* file name		*/
+};
+
+struct adfs_dir_ops {
+	int	(*read)(struct super_block *sb, unsigned int indaddr,
+			unsigned int size, struct adfs_dir *dir);
+	int	(*iterate)(struct adfs_dir *dir, struct dir_context *ctx);
+	int	(*setpos)(struct adfs_dir *dir, unsigned int fpos);
+	int	(*getnext)(struct adfs_dir *dir, struct object_info *obj);
+	int	(*update)(struct adfs_dir *dir, struct object_info *obj);
+	int	(*create)(struct adfs_dir *dir, struct object_info *obj);
+	int	(*remove)(struct adfs_dir *dir, struct object_info *obj);
+	int	(*commit)(struct adfs_dir *dir);
+};
+
+struct adfs_discmap {
+	struct buffer_head	*dm_bh;
+	__u32			dm_startblk;
+	unsigned int		dm_startbit;
+	unsigned int		dm_endbit;
+};
+
+/* Inode stuff */
+struct inode *adfs_iget(struct super_block *sb, struct object_info *obj);
+int adfs_write_inode(struct inode *inode, struct writeback_control *wbc);
+int adfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+		struct iattr *attr);
+
+/* map.c */
+int adfs_map_lookup(struct super_block *sb, u32 frag_id, unsigned int offset);
+void adfs_map_statfs(struct super_block *sb, struct kstatfs *buf);
+struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr);
+void adfs_free_map(struct super_block *sb);
+
+/* Misc */
+__printf(3, 4)
+void __adfs_error(struct super_block *sb, const char *function,
+		  const char *fmt, ...);
+#define adfs_error(sb, fmt...) __adfs_error(sb, __func__, fmt)
+void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...);
+
+/* super.c */
+
+/*
+ * Inodes and file operations
+ */
+
+/* dir_*.c */
+extern const struct inode_operations adfs_dir_inode_operations;
+extern const struct file_operations adfs_dir_operations;
+extern const struct dentry_operations adfs_dentry_operations;
+extern const struct adfs_dir_ops adfs_f_dir_ops;
+extern const struct adfs_dir_ops adfs_fplus_dir_ops;
+
+int adfs_dir_copyfrom(void *dst, struct adfs_dir *dir, unsigned int offset,
+		      size_t len);
+int adfs_dir_copyto(struct adfs_dir *dir, unsigned int offset, const void *src,
+		    size_t len);
+void adfs_dir_relse(struct adfs_dir *dir);
+int adfs_dir_read_buffers(struct super_block *sb, u32 indaddr,
+			  unsigned int size, struct adfs_dir *dir);
+void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj);
+extern int adfs_dir_update(struct super_block *sb, struct object_info *obj,
+			   int wait);
+
+/* file.c */
+extern const struct inode_operations adfs_file_inode_operations;
+extern const struct file_operations adfs_file_operations;
+
+static inline __u32 signed_asl(__u32 val, signed int shift)
+{
+	if (shift >= 0)
+		val <<= shift;
+	else
+		val >>= -shift;
+	return val;
+}
+
+/*
+ * Calculate the address of a block in an object given the block offset
+ * and the object identity.
+ *
+ * The root directory ID should always be looked up in the map [3.4]
+ */
+static inline int __adfs_block_map(struct super_block *sb, u32 indaddr,
+				   unsigned int block)
+{
+	if (indaddr & 255) {
+		unsigned int off;
+
+		off = (indaddr & 255) - 1;
+		block += off << ADFS_SB(sb)->s_log2sharesize;
+	}
+
+	return adfs_map_lookup(sb, indaddr >> 8, block);
+}
+
+/* Return the disc record from the map */
+static inline
+struct adfs_discrecord *adfs_map_discrecord(struct adfs_discmap *dm)
+{
+	return (void *)(dm[0].dm_bh->b_data + 4);
+}
+
+static inline u64 adfs_disc_size(const struct adfs_discrecord *dr)
+{
+	return (u64)le32_to_cpu(dr->disc_size_high) << 32 |
+		    le32_to_cpu(dr->disc_size);
+}
diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c
new file mode 100644
index 000000000..11afa9e15
--- /dev/null
+++ b/fs/adfs/dir.c
@@ -0,0 +1,458 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/adfs/dir.c
+ *
+ *  Copyright (C) 1999-2000 Russell King
+ *
+ *  Common directory handling for ADFS
+ */
+#include <linux/hex.h>
+#include <linux/slab.h>
+#include "adfs.h"
+
+/*
+ * For future.  This should probably be per-directory.
+ */
+static DECLARE_RWSEM(adfs_dir_rwsem);
+
+int adfs_dir_copyfrom(void *dst, struct adfs_dir *dir, unsigned int offset,
+		      size_t len)
+{
+	struct super_block *sb = dir->sb;
+	unsigned int index, remain;
+
+	index = offset >> sb->s_blocksize_bits;
+	offset &= sb->s_blocksize - 1;
+	remain = sb->s_blocksize - offset;
+	if (index + (remain < len) >= dir->nr_buffers)
+		return -EINVAL;
+
+	if (remain < len) {
+		memcpy(dst, dir->bhs[index]->b_data + offset, remain);
+		dst += remain;
+		len -= remain;
+		index += 1;
+		offset = 0;
+	}
+
+	memcpy(dst, dir->bhs[index]->b_data + offset, len);
+
+	return 0;
+}
+
+int adfs_dir_copyto(struct adfs_dir *dir, unsigned int offset, const void *src,
+		    size_t len)
+{
+	struct super_block *sb = dir->sb;
+	unsigned int index, remain;
+
+	index = offset >> sb->s_blocksize_bits;
+	offset &= sb->s_blocksize - 1;
+	remain = sb->s_blocksize - offset;
+	if (index + (remain < len) >= dir->nr_buffers)
+		return -EINVAL;
+
+	if (remain < len) {
+		memcpy(dir->bhs[index]->b_data + offset, src, remain);
+		src += remain;
+		len -= remain;
+		index += 1;
+		offset = 0;
+	}
+
+	memcpy(dir->bhs[index]->b_data + offset, src, len);
+
+	return 0;
+}
+
+static void __adfs_dir_cleanup(struct adfs_dir *dir)
+{
+	dir->nr_buffers = 0;
+
+	if (dir->bhs != dir->bh)
+		kfree(dir->bhs);
+	dir->bhs = NULL;
+	dir->sb = NULL;
+}
+
+void adfs_dir_relse(struct adfs_dir *dir)
+{
+	unsigned int i;
+
+	for (i = 0; i < dir->nr_buffers; i++)
+		brelse(dir->bhs[i]);
+
+	__adfs_dir_cleanup(dir);
+}
+
+static void adfs_dir_forget(struct adfs_dir *dir)
+{
+	unsigned int i;
+
+	for (i = 0; i < dir->nr_buffers; i++)
+		bforget(dir->bhs[i]);
+
+	__adfs_dir_cleanup(dir);
+}
+
+int adfs_dir_read_buffers(struct super_block *sb, u32 indaddr,
+			  unsigned int size, struct adfs_dir *dir)
+{
+	struct buffer_head **bhs;
+	unsigned int i, num;
+	int block;
+
+	num = ALIGN(size, sb->s_blocksize) >> sb->s_blocksize_bits;
+	if (num > ARRAY_SIZE(dir->bh)) {
+		/* We only allow one extension */
+		if (dir->bhs != dir->bh)
+			return -EINVAL;
+
+		bhs = kzalloc_objs(*bhs, num);
+		if (!bhs)
+			return -ENOMEM;
+
+		if (dir->nr_buffers)
+			memcpy(bhs, dir->bhs, dir->nr_buffers * sizeof(*bhs));
+
+		dir->bhs = bhs;
+	}
+
+	for (i = dir->nr_buffers; i < num; i++) {
+		block = __adfs_block_map(sb, indaddr, i);
+		if (!block) {
+			adfs_error(sb, "dir %06x has a hole at offset %u",
+				   indaddr, i);
+			goto error;
+		}
+
+		dir->bhs[i] = sb_bread(sb, block);
+		if (!dir->bhs[i]) {
+			adfs_error(sb,
+				   "dir %06x failed read at offset %u, mapped block 0x%08x",
+				   indaddr, i, block);
+			goto error;
+		}
+
+		dir->nr_buffers++;
+	}
+	return 0;
+
+error:
+	adfs_dir_relse(dir);
+
+	return -EIO;
+}
+
+static int adfs_dir_read(struct super_block *sb, u32 indaddr,
+			 unsigned int size, struct adfs_dir *dir)
+{
+	dir->sb = sb;
+	dir->bhs = dir->bh;
+	dir->nr_buffers = 0;
+
+	return ADFS_SB(sb)->s_dir->read(sb, indaddr, size, dir);
+}
+
+static int adfs_dir_read_inode(struct super_block *sb, struct inode *inode,
+			       struct adfs_dir *dir)
+{
+	int ret;
+
+	ret = adfs_dir_read(sb, ADFS_I(inode)->indaddr, inode->i_size, dir);
+	if (ret)
+		return ret;
+
+	if (ADFS_I(inode)->parent_id != dir->parent_id) {
+		adfs_error(sb,
+			   "parent directory id changed under me! (%06x but got %06x)\n",
+			   ADFS_I(inode)->parent_id, dir->parent_id);
+		adfs_dir_relse(dir);
+		ret = -EIO;
+	}
+
+	return ret;
+}
+
+static void adfs_dir_mark_dirty(struct adfs_dir *dir)
+{
+	unsigned int i;
+
+	/* Mark the buffers dirty */
+	for (i = 0; i < dir->nr_buffers; i++)
+		mark_buffer_dirty(dir->bhs[i]);
+}
+
+static int adfs_dir_sync(struct adfs_dir *dir)
+{
+	int err = 0;
+	int i;
+
+	for (i = dir->nr_buffers - 1; i >= 0; i--) {
+		struct buffer_head *bh = dir->bhs[i];
+		sync_dirty_buffer(bh);
+		if (buffer_req(bh) && !buffer_uptodate(bh))
+			err = -EIO;
+	}
+
+	return err;
+}
+
+void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj)
+{
+	unsigned int dots, i;
+
+	/*
+	 * RISC OS allows the use of '/' in directory entry names, so we need
+	 * to fix these up.  '/' is typically used for FAT compatibility to
+	 * represent '.', so do the same conversion here.  In any case, '.'
+	 * will never be in a RISC OS name since it is used as the pathname
+	 * separator.  Handle the case where we may generate a '.' or '..'
+	 * name, replacing the first character with '^' (the RISC OS "parent
+	 * directory" character.)
+	 */
+	for (i = dots = 0; i < obj->name_len; i++)
+		if (obj->name[i] == '/') {
+			obj->name[i] = '.';
+			dots++;
+		}
+
+	if (obj->name_len <= 2 && dots == obj->name_len)
+		obj->name[0] = '^';
+
+	/*
+	 * If the object is a file, and the user requested the ,xyz hex
+	 * filetype suffix to the name, check the filetype and append.
+	 */
+	if (!(obj->attr & ADFS_NDA_DIRECTORY) && ADFS_SB(dir->sb)->s_ftsuffix) {
+		u16 filetype = adfs_filetype(obj->loadaddr);
+
+		if (filetype != ADFS_FILETYPE_NONE) {
+			obj->name[obj->name_len++] = ',';
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 8);
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 4);
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 0);
+		}
+	}
+}
+
+static int adfs_iterate(struct file *file, struct dir_context *ctx)
+{
+	struct inode *inode = file_inode(file);
+	struct super_block *sb = inode->i_sb;
+	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
+	struct adfs_dir dir;
+	int ret;
+
+	down_read(&adfs_dir_rwsem);
+	ret = adfs_dir_read_inode(sb, inode, &dir);
+	if (ret)
+		goto unlock;
+
+	if (ctx->pos == 0) {
+		if (!dir_emit_dot(file, ctx))
+			goto unlock_relse;
+		ctx->pos = 1;
+	}
+	if (ctx->pos == 1) {
+		if (!dir_emit(ctx, "..", 2, dir.parent_id, DT_DIR))
+			goto unlock_relse;
+		ctx->pos = 2;
+	}
+
+	ret = ops->iterate(&dir, ctx);
+
+unlock_relse:
+	up_read(&adfs_dir_rwsem);
+	adfs_dir_relse(&dir);
+	return ret;
+
+unlock:
+	up_read(&adfs_dir_rwsem);
+	return ret;
+}
+
+int
+adfs_dir_update(struct super_block *sb, struct object_info *obj, int wait)
+{
+	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
+	struct adfs_dir dir;
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_ADFS_FS_RW))
+		return -EINVAL;
+
+	if (!ops->update)
+		return -EINVAL;
+
+	down_write(&adfs_dir_rwsem);
+	ret = adfs_dir_read(sb, obj->parent_id, 0, &dir);
+	if (ret)
+		goto unlock;
+
+	ret = ops->update(&dir, obj);
+	if (ret)
+		goto forget;
+
+	ret = ops->commit(&dir);
+	if (ret)
+		goto forget;
+	up_write(&adfs_dir_rwsem);
+
+	adfs_dir_mark_dirty(&dir);
+
+	if (wait)
+		ret = adfs_dir_sync(&dir);
+
+	adfs_dir_relse(&dir);
+	return ret;
+
+	/*
+	 * If the updated failed because the entry wasn't found, we can
+	 * just release the buffers. If it was any other error, forget
+	 * the dirtied buffers so they aren't written back to the media.
+	 */
+forget:
+	if (ret == -ENOENT)
+		adfs_dir_relse(&dir);
+	else
+		adfs_dir_forget(&dir);
+unlock:
+	up_write(&adfs_dir_rwsem);
+
+	return ret;
+}
+
+static unsigned char adfs_tolower(unsigned char c)
+{
+	if (c >= 'A' && c <= 'Z')
+		c += 'a' - 'A';
+	return c;
+}
+
+static int __adfs_compare(const unsigned char *qstr, u32 qlen,
+			  const char *str, u32 len)
+{
+	u32 i;
+
+	if (qlen != len)
+		return 1;
+
+	for (i = 0; i < qlen; i++)
+		if (adfs_tolower(qstr[i]) != adfs_tolower(str[i]))
+			return 1;
+
+	return 0;
+}
+
+static int adfs_dir_lookup_byname(struct inode *inode, const struct qstr *qstr,
+				  struct object_info *obj)
+{
+	struct super_block *sb = inode->i_sb;
+	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
+	const unsigned char *name;
+	struct adfs_dir dir;
+	u32 name_len;
+	int ret;
+
+	down_read(&adfs_dir_rwsem);
+	ret = adfs_dir_read_inode(sb, inode, &dir);
+	if (ret)
+		goto unlock;
+
+	ret = ops->setpos(&dir, 0);
+	if (ret)
+		goto unlock_relse;
+
+	ret = -ENOENT;
+	name = qstr->name;
+	name_len = qstr->len;
+	while (ops->getnext(&dir, obj) == 0) {
+		if (!__adfs_compare(name, name_len, obj->name, obj->name_len)) {
+			ret = 0;
+			break;
+		}
+	}
+	obj->parent_id = ADFS_I(inode)->indaddr;
+
+unlock_relse:
+	up_read(&adfs_dir_rwsem);
+	adfs_dir_relse(&dir);
+	return ret;
+
+unlock:
+	up_read(&adfs_dir_rwsem);
+	return ret;
+}
+
+const struct file_operations adfs_dir_operations = {
+	.read		= generic_read_dir,
+	.llseek		= generic_file_llseek,
+	.iterate_shared	= adfs_iterate,
+	.fsync		= simple_fsync,
+};
+
+static int
+adfs_hash(const struct dentry *parent, struct qstr *qstr)
+{
+	const unsigned char *name;
+	unsigned long hash;
+	u32 len;
+
+	if (qstr->len > ADFS_SB(parent->d_sb)->s_namelen)
+		return -ENAMETOOLONG;
+
+	len = qstr->len;
+	name = qstr->name;
+	hash = init_name_hash(parent);
+	while (len--)
+		hash = partial_name_hash(adfs_tolower(*name++), hash);
+	qstr->hash = end_name_hash(hash);
+
+	return 0;
+}
+
+/*
+ * Compare two names, taking note of the name length
+ * requirements of the underlying filesystem.
+ */
+static int adfs_compare(const struct dentry *dentry, unsigned int len,
+			const char *str, const struct qstr *qstr)
+{
+	return __adfs_compare(qstr->name, qstr->len, str, len);
+}
+
+const struct dentry_operations adfs_dentry_operations = {
+	.d_hash		= adfs_hash,
+	.d_compare	= adfs_compare,
+};
+
+static struct dentry *
+adfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+	struct inode *inode = NULL;
+	struct object_info obj;
+	int error;
+
+	error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
+	if (error == 0) {
+		/*
+		 * This only returns NULL if get_empty_inode
+		 * fails.
+		 */
+		inode = adfs_iget(dir->i_sb, &obj);
+		if (!inode)
+			inode = ERR_PTR(-EACCES);
+	} else if (error != -ENOENT) {
+		inode = ERR_PTR(error);
+	}
+	return d_splice_alias(inode, dentry);
+}
+
+/*
+ * directories can handle most operations...
+ */
+const struct inode_operations adfs_dir_inode_operations = {
+	.lookup		= adfs_lookup,
+	.setattr	= adfs_setattr,
+};
diff --git a/fs/adfs/dir_f.c b/fs/adfs/dir_f.c
new file mode 100644
index 000000000..05e963402
--- /dev/null
+++ b/fs/adfs/dir_f.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/adfs/dir_f.c
+ *
+ * Copyright (C) 1997-1999 Russell King
+ *
+ *  E and F format directory handling
+ */
+#include "adfs.h"
+#include "dir_f.h"
+
+/*
+ * Read an (unaligned) value of length 1..4 bytes
+ */
+static inline unsigned int adfs_readval(unsigned char *p, int len)
+{
+	unsigned int val = 0;
+
+	switch (len) {
+	case 4:		val |= p[3] << 24;
+		fallthrough;
+	case 3:		val |= p[2] << 16;
+		fallthrough;
+	case 2:		val |= p[1] << 8;
+		fallthrough;
+	default:	val |= p[0];
+	}
+	return val;
+}
+
+static inline void adfs_writeval(unsigned char *p, int len, unsigned int val)
+{
+	switch (len) {
+	case 4:		p[3] = val >> 24;
+		fallthrough;
+	case 3:		p[2] = val >> 16;
+		fallthrough;
+	case 2:		p[1] = val >> 8;
+		fallthrough;
+	default:	p[0] = val;
+	}
+}
+
+#define ror13(v) ((v >> 13) | (v << 19))
+
+#define dir_u8(idx)				\
+	({ int _buf = idx >> blocksize_bits;	\
+	   int _off = idx - (_buf << blocksize_bits);\
+	  *(u8 *)(bh[_buf]->b_data + _off);	\
+	})
+
+#define dir_u32(idx)				\
+	({ int _buf = idx >> blocksize_bits;	\
+	   int _off = idx - (_buf << blocksize_bits);\
+	  *(__le32 *)(bh[_buf]->b_data + _off);	\
+	})
+
+#define bufoff(_bh,_idx)			\
+	({ int _buf = _idx >> blocksize_bits;	\
+	   int _off = _idx - (_buf << blocksize_bits);\
+	  (void *)(_bh[_buf]->b_data + _off);	\
+	})
+
+/*
+ * There are some algorithms that are nice in
+ * assembler, but a bitch in C...  This is one
+ * of them.
+ */
+static u8
+adfs_dir_checkbyte(const struct adfs_dir *dir)
+{
+	struct buffer_head * const *bh = dir->bh;
+	const int blocksize_bits = dir->sb->s_blocksize_bits;
+	union { __le32 *ptr32; u8 *ptr8; } ptr, end;
+	u32 dircheck = 0;
+	int last = 5 - 26;
+	int i = 0;
+
+	/*
+	 * Accumulate each word up to the last whole
+	 * word of the last directory entry.  This
+	 * can spread across several buffer heads.
+	 */
+	do {
+		last += 26;
+		do {
+			dircheck = le32_to_cpu(dir_u32(i)) ^ ror13(dircheck);
+
+			i += sizeof(u32);
+		} while (i < (last & ~3));
+	} while (dir_u8(last) != 0);
+
+	/*
+	 * Accumulate the last few bytes.  These
+	 * bytes will be within the same bh.
+	 */
+	if (i != last) {
+		ptr.ptr8 = bufoff(bh, i);
+		end.ptr8 = ptr.ptr8 + last - i;
+
+		do {
+			dircheck = *ptr.ptr8++ ^ ror13(dircheck);
+		} while (ptr.ptr8 < end.ptr8);
+	}
+
+	/*
+	 * The directory tail is in the final bh
+	 * Note that contary to the RISC OS PRMs,
+	 * the first few bytes are NOT included
+	 * in the check.  All bytes are in the
+	 * same bh.
+	 */
+	ptr.ptr8 = bufoff(bh, 2008);
+	end.ptr8 = ptr.ptr8 + 36;
+
+	do {
+		__le32 v = *ptr.ptr32++;
+		dircheck = le32_to_cpu(v) ^ ror13(dircheck);
+	} while (ptr.ptr32 < end.ptr32);
+
+	return (dircheck ^ (dircheck >> 8) ^ (dircheck >> 16) ^ (dircheck >> 24)) & 0xff;
+}
+
+static int adfs_f_validate(struct adfs_dir *dir)
+{
+	struct adfs_dirheader *head = dir->dirhead;
+	struct adfs_newdirtail *tail = dir->newtail;
+
+	if (head->startmasseq != tail->endmasseq ||
+	    tail->dirlastmask || tail->reserved[0] || tail->reserved[1] ||
+	    (memcmp(&head->startname, "Nick", 4) &&
+	     memcmp(&head->startname, "Hugo", 4)) ||
+	    memcmp(&head->startname, &tail->endname, 4) ||
+	    adfs_dir_checkbyte(dir) != tail->dircheckbyte)
+		return -EIO;
+
+	return 0;
+}
+
+/* Read and check that a directory is valid */
+static int adfs_f_read(struct super_block *sb, u32 indaddr, unsigned int size,
+		       struct adfs_dir *dir)
+{
+	const unsigned int blocksize_bits = sb->s_blocksize_bits;
+	int ret;
+
+	if (size && size != ADFS_NEWDIR_SIZE)
+		return -EIO;
+
+	ret = adfs_dir_read_buffers(sb, indaddr, ADFS_NEWDIR_SIZE, dir);
+	if (ret)
+		return ret;
+
+	dir->dirhead = bufoff(dir->bh, 0);
+	dir->newtail = bufoff(dir->bh, 2007);
+
+	if (adfs_f_validate(dir))
+		goto bad_dir;
+
+	dir->parent_id = adfs_readval(dir->newtail->dirparent, 3);
+
+	return 0;
+
+bad_dir:
+	adfs_error(sb, "dir %06x is corrupted", indaddr);
+	adfs_dir_relse(dir);
+
+	return -EIO;
+}
+
+/*
+ * convert a disk-based directory entry to a Linux ADFS directory entry
+ */
+static inline void
+adfs_dir2obj(struct adfs_dir *dir, struct object_info *obj,
+	struct adfs_direntry *de)
+{
+	unsigned int name_len;
+
+	for (name_len = 0; name_len < ADFS_F_NAME_LEN; name_len++) {
+		if (de->dirobname[name_len] < ' ')
+			break;
+
+		obj->name[name_len] = de->dirobname[name_len];
+	}
+
+	obj->name_len =	name_len;
+	obj->indaddr  = adfs_readval(de->dirinddiscadd, 3);
+	obj->loadaddr = adfs_readval(de->dirload, 4);
+	obj->execaddr = adfs_readval(de->direxec, 4);
+	obj->size     = adfs_readval(de->dirlen,  4);
+	obj->attr     = de->newdiratts;
+
+	adfs_object_fixup(dir, obj);
+}
+
+/*
+ * convert a Linux ADFS directory entry to a disk-based directory entry
+ */
+static inline void
+adfs_obj2dir(struct adfs_direntry *de, struct object_info *obj)
+{
+	adfs_writeval(de->dirinddiscadd, 3, obj->indaddr);
+	adfs_writeval(de->dirload, 4, obj->loadaddr);
+	adfs_writeval(de->direxec, 4, obj->execaddr);
+	adfs_writeval(de->dirlen,  4, obj->size);
+	de->newdiratts = obj->attr;
+}
+
+/*
+ * get a directory entry.  Note that the caller is responsible
+ * for holding the relevant locks.
+ */
+static int
+__adfs_dir_get(struct adfs_dir *dir, int pos, struct object_info *obj)
+{
+	struct adfs_direntry de;
+	int ret;
+
+	ret = adfs_dir_copyfrom(&de, dir, pos, 26);
+	if (ret)
+		return ret;
+
+	if (!de.dirobname[0])
+		return -ENOENT;
+
+	adfs_dir2obj(dir, obj, &de);
+
+	return 0;
+}
+
+static int
+adfs_f_setpos(struct adfs_dir *dir, unsigned int fpos)
+{
+	if (fpos >= ADFS_NUM_DIR_ENTRIES)
+		return -ENOENT;
+
+	dir->pos = 5 + fpos * 26;
+	return 0;
+}
+
+static int
+adfs_f_getnext(struct adfs_dir *dir, struct object_info *obj)
+{
+	unsigned int ret;
+
+	ret = __adfs_dir_get(dir, dir->pos, obj);
+	if (ret == 0)
+		dir->pos += 26;
+
+	return ret;
+}
+
+static int adfs_f_iterate(struct adfs_dir *dir, struct dir_context *ctx)
+{
+	struct object_info obj;
+	int pos = 5 + (ctx->pos - 2) * 26;
+
+	while (ctx->pos < 2 + ADFS_NUM_DIR_ENTRIES) {
+		if (__adfs_dir_get(dir, pos, &obj))
+			break;
+		if (!dir_emit(ctx, obj.name, obj.name_len,
+			      obj.indaddr, DT_UNKNOWN))
+			break;
+		pos += 26;
+		ctx->pos++;
+	}
+	return 0;
+}
+
+static int adfs_f_update(struct adfs_dir *dir, struct object_info *obj)
+{
+	struct adfs_direntry de;
+	int offset, ret;
+
+	offset = 5 - (int)sizeof(de);
+
+	do {
+		offset += sizeof(de);
+		ret = adfs_dir_copyfrom(&de, dir, offset, sizeof(de));
+		if (ret) {
+			adfs_error(dir->sb, "error reading directory entry");
+			return -ENOENT;
+		}
+		if (!de.dirobname[0]) {
+			adfs_error(dir->sb, "unable to locate entry to update");
+			return -ENOENT;
+		}
+	} while (adfs_readval(de.dirinddiscadd, 3) != obj->indaddr);
+
+	/* Update the directory entry with the new object state */
+	adfs_obj2dir(&de, obj);
+
+	/* Write the directory entry back to the directory */
+	return adfs_dir_copyto(dir, offset, &de, 26);
+}
+
+static int adfs_f_commit(struct adfs_dir *dir)
+{
+	int ret;
+
+	/* Increment directory sequence number */
+	dir->dirhead->startmasseq += 1;
+	dir->newtail->endmasseq += 1;
+
+	/* Update directory check byte */
+	dir->newtail->dircheckbyte = adfs_dir_checkbyte(dir);
+
+	/* Make sure the directory still validates correctly */
+	ret = adfs_f_validate(dir);
+	if (ret)
+		adfs_msg(dir->sb, KERN_ERR, "error: update broke directory");
+
+	return ret;
+}
+
+const struct adfs_dir_ops adfs_f_dir_ops = {
+	.read		= adfs_f_read,
+	.iterate	= adfs_f_iterate,
+	.setpos		= adfs_f_setpos,
+	.getnext	= adfs_f_getnext,
+	.update		= adfs_f_update,
+	.commit		= adfs_f_commit,
+};
diff --git a/fs/adfs/dir_f.h b/fs/adfs/dir_f.h
new file mode 100644
index 000000000..4e6c53d59
--- /dev/null
+++ b/fs/adfs/dir_f.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  linux/fs/adfs/dir_f.h
+ *
+ *  Copyright (C) 1999 Russell King
+ *
+ *  Structures of directories on the F format disk
+ */
+#ifndef ADFS_DIR_F_H
+#define ADFS_DIR_F_H
+
+/*
+ * Directory header
+ */
+struct adfs_dirheader {
+	__u8 startmasseq;
+	__u8 startname[4];
+} __attribute__((packed));
+
+#define ADFS_NEWDIR_SIZE	2048
+#define ADFS_NUM_DIR_ENTRIES	77
+
+/*
+ * Directory entries
+ */
+struct adfs_direntry {
+#define ADFS_F_NAME_LEN 10
+	char dirobname[ADFS_F_NAME_LEN];
+	__u8 dirload[4];
+	__u8 direxec[4];
+	__u8 dirlen[4];
+	__u8 dirinddiscadd[3];
+	__u8 newdiratts;
+} __attribute__((packed));
+
+/*
+ * Directory tail
+ */
+struct adfs_olddirtail {
+	__u8 dirlastmask;
+	char dirname[10];
+	__u8 dirparent[3];
+	char dirtitle[19];
+	__u8 reserved[14];
+	__u8 endmasseq;
+	__u8 endname[4];
+	__u8 dircheckbyte;
+} __attribute__((packed));
+
+struct adfs_newdirtail {
+	__u8 dirlastmask;
+	__u8 reserved[2];
+	__u8 dirparent[3];
+	char dirtitle[19];
+	char dirname[10];
+	__u8 endmasseq;
+	__u8 endname[4];
+	__u8 dircheckbyte;
+} __attribute__((packed));
+
+#endif
diff --git a/fs/adfs/dir_fplus.c b/fs/adfs/dir_fplus.c
new file mode 100644
index 000000000..4a1592401
--- /dev/null
+++ b/fs/adfs/dir_fplus.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/adfs/dir_fplus.c
+ *
+ *  Copyright (C) 1997-1999 Russell King
+ */
+#include "adfs.h"
+#include "dir_fplus.h"
+
+/* Return the byte offset to directory entry pos */
+static unsigned int adfs_fplus_offset(const struct adfs_bigdirheader *h,
+				      unsigned int pos)
+{
+	return offsetof(struct adfs_bigdirheader, bigdirname) +
+	       ALIGN(le32_to_cpu(h->bigdirnamelen), 4) +
+	       pos * sizeof(struct adfs_bigdirentry);
+}
+
+static int adfs_fplus_validate_header(const struct adfs_bigdirheader *h)
+{
+	unsigned int size = le32_to_cpu(h->bigdirsize);
+	unsigned int len;
+
+	if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
+	    h->bigdirversion[2] != 0 ||
+	    h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME) ||
+	    !size || size & 2047 || size > SZ_4M)
+		return -EIO;
+
+	size -= sizeof(struct adfs_bigdirtail) +
+		offsetof(struct adfs_bigdirheader, bigdirname);
+
+	/* Check that bigdirnamelen fits within the directory */
+	len = ALIGN(le32_to_cpu(h->bigdirnamelen), 4);
+	if (len > size)
+		return -EIO;
+
+	size -= len;
+
+	/* Check that bigdirnamesize fits within the directory */
+	len = le32_to_cpu(h->bigdirnamesize);
+	if (len > size)
+		return -EIO;
+
+	size -= len;
+
+	/*
+	 * Avoid division, we know that absolute maximum number of entries
+	 * can not be so large to cause overflow of the multiplication below.
+	 */
+	len = le32_to_cpu(h->bigdirentries);
+	if (len > SZ_4M / sizeof(struct adfs_bigdirentry) ||
+	    len * sizeof(struct adfs_bigdirentry) > size)
+		return -EIO;
+
+	return 0;
+}
+
+static int adfs_fplus_validate_tail(const struct adfs_bigdirheader *h,
+				    const struct adfs_bigdirtail *t)
+{
+	if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
+	    t->bigdirendmasseq != h->startmasseq ||
+	    t->reserved[0] != 0 || t->reserved[1] != 0)
+		return -EIO;
+
+	return 0;
+}
+
+static u8 adfs_fplus_checkbyte(struct adfs_dir *dir)
+{
+	struct adfs_bigdirheader *h = dir->bighead;
+	struct adfs_bigdirtail *t = dir->bigtail;
+	unsigned int end, bs, bi, i;
+	__le32 *bp;
+	u32 dircheck;
+
+	end = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries)) +
+		le32_to_cpu(h->bigdirnamesize);
+
+	/* Accumulate the contents of the header, entries and names */
+	for (dircheck = 0, bi = 0; end; bi++) {
+		bp = (void *)dir->bhs[bi]->b_data;
+		bs = dir->bhs[bi]->b_size;
+		if (bs > end)
+			bs = end;
+
+		for (i = 0; i < bs; i += sizeof(u32))
+			dircheck = ror32(dircheck, 13) ^ le32_to_cpup(bp++);
+
+		end -= bs;
+	}
+
+	/* Accumulate the contents of the tail except for the check byte */
+	dircheck = ror32(dircheck, 13) ^ le32_to_cpu(t->bigdirendname);
+	dircheck = ror32(dircheck, 13) ^ t->bigdirendmasseq;
+	dircheck = ror32(dircheck, 13) ^ t->reserved[0];
+	dircheck = ror32(dircheck, 13) ^ t->reserved[1];
+
+	return dircheck ^ dircheck >> 8 ^ dircheck >> 16 ^ dircheck >> 24;
+}
+
+static int adfs_fplus_read(struct super_block *sb, u32 indaddr,
+			   unsigned int size, struct adfs_dir *dir)
+{
+	struct adfs_bigdirheader *h;
+	struct adfs_bigdirtail *t;
+	unsigned int dirsize;
+	int ret;
+
+	/* Read first buffer */
+	ret = adfs_dir_read_buffers(sb, indaddr, sb->s_blocksize, dir);
+	if (ret)
+		return ret;
+
+	dir->bighead = h = (void *)dir->bhs[0]->b_data;
+	ret = adfs_fplus_validate_header(h);
+	if (ret) {
+		adfs_error(sb, "dir %06x has malformed header", indaddr);
+		goto out;
+	}
+
+	dirsize = le32_to_cpu(h->bigdirsize);
+	if (size && dirsize != size) {
+		adfs_msg(sb, KERN_WARNING,
+			 "dir %06x header size %X does not match directory size %X",
+			 indaddr, dirsize, size);
+	}
+
+	/* Read remaining buffers */
+	ret = adfs_dir_read_buffers(sb, indaddr, dirsize, dir);
+	if (ret)
+		return ret;
+
+	dir->bigtail = t = (struct adfs_bigdirtail *)
+		(dir->bhs[dir->nr_buffers - 1]->b_data + (sb->s_blocksize - 8));
+
+	ret = adfs_fplus_validate_tail(h, t);
+	if (ret) {
+		adfs_error(sb, "dir %06x has malformed tail", indaddr);
+		goto out;
+	}
+
+	if (adfs_fplus_checkbyte(dir) != t->bigdircheckbyte) {
+		adfs_error(sb, "dir %06x checkbyte mismatch\n", indaddr);
+		goto out;
+	}
+
+	dir->parent_id = le32_to_cpu(h->bigdirparent);
+	return 0;
+
+out:
+	adfs_dir_relse(dir);
+
+	return ret;
+}
+
+static int
+adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
+{
+	int ret = -ENOENT;
+
+	if (fpos <= le32_to_cpu(dir->bighead->bigdirentries)) {
+		dir->pos = fpos;
+		ret = 0;
+	}
+
+	return ret;
+}
+
+static int
+adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
+{
+	struct adfs_bigdirheader *h = dir->bighead;
+	struct adfs_bigdirentry bde;
+	unsigned int offset;
+	int ret;
+
+	if (dir->pos >= le32_to_cpu(h->bigdirentries))
+		return -ENOENT;
+
+	offset = adfs_fplus_offset(h, dir->pos);
+
+	ret = adfs_dir_copyfrom(&bde, dir, offset,
+				sizeof(struct adfs_bigdirentry));
+	if (ret)
+		return ret;
+
+	obj->loadaddr = le32_to_cpu(bde.bigdirload);
+	obj->execaddr = le32_to_cpu(bde.bigdirexec);
+	obj->size     = le32_to_cpu(bde.bigdirlen);
+	obj->indaddr  = le32_to_cpu(bde.bigdirindaddr);
+	obj->attr     = le32_to_cpu(bde.bigdirattr);
+	obj->name_len = le32_to_cpu(bde.bigdirobnamelen);
+
+	offset = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries));
+	offset += le32_to_cpu(bde.bigdirobnameptr);
+
+	ret = adfs_dir_copyfrom(obj->name, dir, offset, obj->name_len);
+	if (ret)
+		return ret;
+
+	adfs_object_fixup(dir, obj);
+
+	dir->pos += 1;
+
+	return 0;
+}
+
+static int adfs_fplus_iterate(struct adfs_dir *dir, struct dir_context *ctx)
+{
+	struct object_info obj;
+
+	if ((ctx->pos - 2) >> 32)
+		return 0;
+
+	if (adfs_fplus_setpos(dir, ctx->pos - 2))
+		return 0;
+
+	while (!adfs_fplus_getnext(dir, &obj)) {
+		if (!dir_emit(ctx, obj.name, obj.name_len,
+			      obj.indaddr, DT_UNKNOWN))
+			break;
+		ctx->pos++;
+	}
+
+	return 0;
+}
+
+static int adfs_fplus_update(struct adfs_dir *dir, struct object_info *obj)
+{
+	struct adfs_bigdirheader *h = dir->bighead;
+	struct adfs_bigdirentry bde;
+	int offset, end, ret;
+
+	offset = adfs_fplus_offset(h, 0) - sizeof(bde);
+	end = adfs_fplus_offset(h, le32_to_cpu(h->bigdirentries));
+
+	do {
+		offset += sizeof(bde);
+		if (offset >= end) {
+			adfs_error(dir->sb, "unable to locate entry to update");
+			return -ENOENT;
+		}
+		ret = adfs_dir_copyfrom(&bde, dir, offset, sizeof(bde));
+		if (ret) {
+			adfs_error(dir->sb, "error reading directory entry");
+			return -ENOENT;
+		}
+	} while (le32_to_cpu(bde.bigdirindaddr) != obj->indaddr);
+
+	bde.bigdirload    = cpu_to_le32(obj->loadaddr);
+	bde.bigdirexec    = cpu_to_le32(obj->execaddr);
+	bde.bigdirlen     = cpu_to_le32(obj->size);
+	bde.bigdirindaddr = cpu_to_le32(obj->indaddr);
+	bde.bigdirattr    = cpu_to_le32(obj->attr);
+
+	return adfs_dir_copyto(dir, offset, &bde, sizeof(bde));
+}
+
+static int adfs_fplus_commit(struct adfs_dir *dir)
+{
+	int ret;
+
+	/* Increment directory sequence number */
+	dir->bighead->startmasseq += 1;
+	dir->bigtail->bigdirendmasseq += 1;
+
+	/* Update directory check byte */
+	dir->bigtail->bigdircheckbyte = adfs_fplus_checkbyte(dir);
+
+	/* Make sure the directory still validates correctly */
+	ret = adfs_fplus_validate_header(dir->bighead);
+	if (ret == 0)
+		ret = adfs_fplus_validate_tail(dir->bighead, dir->bigtail);
+
+	return ret;
+}
+
+const struct adfs_dir_ops adfs_fplus_dir_ops = {
+	.read		= adfs_fplus_read,
+	.iterate	= adfs_fplus_iterate,
+	.setpos		= adfs_fplus_setpos,
+	.getnext	= adfs_fplus_getnext,
+	.update		= adfs_fplus_update,
+	.commit		= adfs_fplus_commit,
+};
diff --git a/fs/adfs/dir_fplus.h b/fs/adfs/dir_fplus.h
new file mode 100644
index 000000000..d729b1591
--- /dev/null
+++ b/fs/adfs/dir_fplus.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  linux/fs/adfs/dir_fplus.h
+ *
+ *  Copyright (C) 1999 Russell King
+ *
+ *  Structures of directories on the F+ format disk
+ */
+
+#define ADFS_FPLUS_NAME_LEN	255
+
+#define BIGDIRSTARTNAME ('S' | 'B' << 8 | 'P' << 16 | 'r' << 24)
+#define BIGDIRENDNAME	('o' | 'v' << 8 | 'e' << 16 | 'n' << 24)
+
+struct adfs_bigdirheader {
+	__u8	startmasseq;
+	__u8	bigdirversion[3];
+	__le32	bigdirstartname;
+	__le32	bigdirnamelen;
+	__le32	bigdirsize;
+	__le32	bigdirentries;
+	__le32	bigdirnamesize;
+	__le32	bigdirparent;
+	char	bigdirname[1];
+} __attribute__((packed, aligned(4)));
+
+struct adfs_bigdirentry {
+	__le32	bigdirload;
+	__le32	bigdirexec;
+	__le32	bigdirlen;
+	__le32	bigdirindaddr;
+	__le32	bigdirattr;
+	__le32	bigdirobnamelen;
+	__le32	bigdirobnameptr;
+} __attribute__((packed, aligned(4)));
+
+struct adfs_bigdirtail {
+	__le32	bigdirendname;
+	__u8	bigdirendmasseq;
+	__u8	reserved[2];
+	__u8	bigdircheckbyte;
+} __attribute__((packed, aligned(4)));
diff --git a/fs/adfs/file.c b/fs/adfs/file.c
new file mode 100644
index 000000000..d056d48c6
--- /dev/null
+++ b/fs/adfs/file.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/adfs/file.c
+ *
+ * Copyright (C) 1997-1999 Russell King
+ * from:
+ *
+ *  linux/fs/ext2/file.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/file.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  adfs regular file handling primitives           
+ */
+#include "adfs.h"
+
+const struct file_operations adfs_file_operations = {
+	.llseek		= generic_file_llseek,
+	.read_iter	= generic_file_read_iter,
+	.mmap_prepare	= generic_file_mmap_prepare,
+	.fsync		= simple_fsync,
+	.write_iter	= generic_file_write_iter,
+	.splice_read	= filemap_splice_read,
+};
+
+const struct inode_operations adfs_file_inode_operations = {
+	.setattr	= adfs_setattr,
+};
diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c
new file mode 100644
index 000000000..4ac442d0a
--- /dev/null
+++ b/fs/adfs/inode.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/adfs/inode.c
+ *
+ *  Copyright (C) 1997-1999 Russell King
+ */
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include <linux/writeback.h>
+#include "adfs.h"
+
+/*
+ * Lookup/Create a block at offset 'block' into 'inode'.  We currently do
+ * not support creation of new blocks, so we return -EIO for this case.
+ */
+static int
+adfs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh,
+	       int create)
+{
+	if (!create) {
+		if (block >= inode->i_blocks)
+			goto abort_toobig;
+
+		block = __adfs_block_map(inode->i_sb, ADFS_I(inode)->indaddr,
+					 block);
+		if (block)
+			map_bh(bh, inode->i_sb, block);
+		return 0;
+	}
+	/* don't support allocation of blocks yet */
+	return -EIO;
+
+abort_toobig:
+	return 0;
+}
+
+static int adfs_writepages(struct address_space *mapping,
+		struct writeback_control *wbc)
+{
+	return mpage_writepages(mapping, wbc, adfs_get_block);
+}
+
+static int adfs_read_folio(struct file *file, struct folio *folio)
+{
+	return block_read_full_folio(folio, adfs_get_block);
+}
+
+static void adfs_write_failed(struct address_space *mapping, loff_t to)
+{
+	struct inode *inode = mapping->host;
+
+	if (to > inode->i_size)
+		truncate_pagecache(inode, inode->i_size);
+}
+
+static int adfs_write_begin(const struct kiocb *iocb,
+			    struct address_space *mapping,
+			    loff_t pos, unsigned len,
+			    struct folio **foliop, void **fsdata)
+{
+	int ret;
+
+	ret = cont_write_begin(iocb, mapping, pos, len, foliop, fsdata,
+				adfs_get_block,
+				&ADFS_I(mapping->host)->mmu_private);
+	if (unlikely(ret))
+		adfs_write_failed(mapping, pos + len);
+
+	return ret;
+}
+
+static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping, block, adfs_get_block);
+}
+
+static const struct address_space_operations adfs_aops = {
+	.dirty_folio	= block_dirty_folio,
+	.invalidate_folio = block_invalidate_folio,
+	.read_folio	= adfs_read_folio,
+	.writepages	= adfs_writepages,
+	.write_begin	= adfs_write_begin,
+	.write_end	= generic_write_end,
+	.migrate_folio	= buffer_migrate_folio,
+	.bmap		= _adfs_bmap,
+};
+
+/*
+ * Convert ADFS attributes and filetype to Linux permission.
+ */
+static umode_t
+adfs_atts2mode(struct super_block *sb, struct inode *inode)
+{
+	unsigned int attr = ADFS_I(inode)->attr;
+	umode_t mode, rmask;
+	struct adfs_sb_info *asb = ADFS_SB(sb);
+
+	if (attr & ADFS_NDA_DIRECTORY) {
+		mode = S_IRUGO & asb->s_owner_mask;
+		return S_IFDIR | S_IXUGO | mode;
+	}
+
+	switch (adfs_filetype(ADFS_I(inode)->loadaddr)) {
+	case 0xfc0:	/* LinkFS */
+		return S_IFLNK|S_IRWXUGO;
+
+	case 0xfe6:	/* UnixExec */
+		rmask = S_IRUGO | S_IXUGO;
+		break;
+
+	default:
+		rmask = S_IRUGO;
+	}
+
+	mode = S_IFREG;
+
+	if (attr & ADFS_NDA_OWNER_READ)
+		mode |= rmask & asb->s_owner_mask;
+
+	if (attr & ADFS_NDA_OWNER_WRITE)
+		mode |= S_IWUGO & asb->s_owner_mask;
+
+	if (attr & ADFS_NDA_PUBLIC_READ)
+		mode |= rmask & asb->s_other_mask;
+
+	if (attr & ADFS_NDA_PUBLIC_WRITE)
+		mode |= S_IWUGO & asb->s_other_mask;
+	return mode;
+}
+
+/*
+ * Convert Linux permission to ADFS attribute.  We try to do the reverse
+ * of atts2mode, but there is not a 1:1 translation.
+ */
+static int adfs_mode2atts(struct super_block *sb, struct inode *inode,
+			  umode_t ia_mode)
+{
+	struct adfs_sb_info *asb = ADFS_SB(sb);
+	umode_t mode;
+	int attr;
+
+	/* FIXME: should we be able to alter a link? */
+	if (S_ISLNK(inode->i_mode))
+		return ADFS_I(inode)->attr;
+
+	/* Directories do not have read/write permissions on the media */
+	if (S_ISDIR(inode->i_mode))
+		return ADFS_NDA_DIRECTORY;
+
+	attr = 0;
+	mode = ia_mode & asb->s_owner_mask;
+	if (mode & S_IRUGO)
+		attr |= ADFS_NDA_OWNER_READ;
+	if (mode & S_IWUGO)
+		attr |= ADFS_NDA_OWNER_WRITE;
+
+	mode = ia_mode & asb->s_other_mask;
+	mode &= ~asb->s_owner_mask;
+	if (mode & S_IRUGO)
+		attr |= ADFS_NDA_PUBLIC_READ;
+	if (mode & S_IWUGO)
+		attr |= ADFS_NDA_PUBLIC_WRITE;
+
+	return attr;
+}
+
+static const s64 nsec_unix_epoch_diff_risc_os_epoch = 2208988800000000000LL;
+
+/*
+ * Convert an ADFS time to Unix time.  ADFS has a 40-bit centi-second time
+ * referenced to 1 Jan 1900 (til 2248) so we need to discard 2208988800 seconds
+ * of time to convert from RISC OS epoch to Unix epoch.
+ */
+static void
+adfs_adfs2unix_time(struct timespec64 *tv, struct inode *inode)
+{
+	unsigned int high, low;
+	/* 01 Jan 1970 00:00:00 (Unix epoch) as nanoseconds since
+	 * 01 Jan 1900 00:00:00 (RISC OS epoch)
+	 */
+	s64 nsec;
+
+	if (!adfs_inode_is_stamped(inode))
+		goto cur_time;
+
+	high = ADFS_I(inode)->loadaddr & 0xFF; /* top 8 bits of timestamp */
+	low  = ADFS_I(inode)->execaddr;    /* bottom 32 bits of timestamp */
+
+	/* convert 40-bit centi-seconds to 32-bit seconds
+	 * going via nanoseconds to retain precision
+	 */
+	nsec = (((s64) high << 32) | (s64) low) * 10000000; /* cs to ns */
+
+	/* Files dated pre  01 Jan 1970 00:00:00. */
+	if (nsec < nsec_unix_epoch_diff_risc_os_epoch)
+		goto too_early;
+
+	/* convert from RISC OS to Unix epoch */
+	nsec -= nsec_unix_epoch_diff_risc_os_epoch;
+
+	*tv = ns_to_timespec64(nsec);
+	return;
+
+ cur_time:
+	*tv = current_time(inode);
+	return;
+
+ too_early:
+	tv->tv_sec = tv->tv_nsec = 0;
+	return;
+}
+
+/* Convert an Unix time to ADFS time for an entry that is already stamped. */
+static void adfs_unix2adfs_time(struct inode *inode,
+				const struct timespec64 *ts)
+{
+	s64 cs, nsec = timespec64_to_ns(ts);
+
+	/* convert from Unix to RISC OS epoch */
+	nsec += nsec_unix_epoch_diff_risc_os_epoch;
+
+	/* convert from nanoseconds to centiseconds */
+	cs = div_s64(nsec, 10000000);
+
+	cs = clamp_t(s64, cs, 0, 0xffffffffff);
+
+	ADFS_I(inode)->loadaddr &= ~0xff;
+	ADFS_I(inode)->loadaddr |= (cs >> 32) & 0xff;
+	ADFS_I(inode)->execaddr = cs;
+}
+
+/*
+ * Fill in the inode information from the object information.
+ *
+ * Note that this is an inode-less filesystem, so we can't use the inode
+ * number to reference the metadata on the media.  Instead, we use the
+ * inode number to hold the object ID, which in turn will tell us where
+ * the data is held.  We also save the parent object ID, and with these
+ * two, we can locate the metadata.
+ *
+ * This does mean that we rely on an objects parent remaining the same at
+ * all times - we cannot cope with a cross-directory rename (yet).
+ */
+struct inode *
+adfs_iget(struct super_block *sb, struct object_info *obj)
+{
+	struct inode *inode;
+	struct timespec64 ts;
+
+	inode = new_inode(sb);
+	if (!inode)
+		goto out;
+
+	inode->i_uid	 = ADFS_SB(sb)->s_uid;
+	inode->i_gid	 = ADFS_SB(sb)->s_gid;
+	inode->i_ino	 = obj->indaddr;
+	inode->i_size	 = obj->size;
+	set_nlink(inode, 2);
+	inode->i_blocks	 = (inode->i_size + sb->s_blocksize - 1) >>
+			    sb->s_blocksize_bits;
+
+	/*
+	 * we need to save the parent directory ID so that
+	 * write_inode can update the directory information
+	 * for this file.  This will need special handling
+	 * for cross-directory renames.
+	 */
+	ADFS_I(inode)->parent_id = obj->parent_id;
+	ADFS_I(inode)->indaddr   = obj->indaddr;
+	ADFS_I(inode)->loadaddr  = obj->loadaddr;
+	ADFS_I(inode)->execaddr  = obj->execaddr;
+	ADFS_I(inode)->attr      = obj->attr;
+
+	inode->i_mode	 = adfs_atts2mode(sb, inode);
+	adfs_adfs2unix_time(&ts, inode);
+	inode_set_atime_to_ts(inode, ts);
+	inode_set_mtime_to_ts(inode, ts);
+	inode_set_ctime_to_ts(inode, ts);
+
+	if (S_ISDIR(inode->i_mode)) {
+		inode->i_op	= &adfs_dir_inode_operations;
+		inode->i_fop	= &adfs_dir_operations;
+	} else if (S_ISREG(inode->i_mode)) {
+		inode->i_op	= &adfs_file_inode_operations;
+		inode->i_fop	= &adfs_file_operations;
+		inode->i_mapping->a_ops = &adfs_aops;
+		ADFS_I(inode)->mmu_private = inode->i_size;
+	}
+
+	inode_fake_hash(inode);
+
+out:
+	return inode;
+}
+
+/*
+ * Validate and convert a changed access mode/time to their ADFS equivalents.
+ * adfs_write_inode will actually write the information back to the directory
+ * later.
+ */
+int
+adfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *attr)
+{
+	struct inode *inode = d_inode(dentry);
+	struct super_block *sb = inode->i_sb;
+	unsigned int ia_valid = attr->ia_valid;
+	int error;
+	
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
+
+	/*
+	 * we can't change the UID or GID of any file -
+	 * we have a global UID/GID in the superblock
+	 */
+	if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, ADFS_SB(sb)->s_uid)) ||
+	    (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, ADFS_SB(sb)->s_gid)))
+		error = -EPERM;
+
+	if (error)
+		goto out;
+
+	/* XXX: this is missing some actual on-disk truncation.. */
+	if (ia_valid & ATTR_SIZE)
+		truncate_setsize(inode, attr->ia_size);
+
+	if (ia_valid & ATTR_MTIME && adfs_inode_is_stamped(inode)) {
+		adfs_unix2adfs_time(inode, &attr->ia_mtime);
+		adfs_adfs2unix_time(&attr->ia_mtime, inode);
+		inode_set_mtime_to_ts(inode, attr->ia_mtime);
+	}
+
+	/*
+	 * FIXME: should we make these == to i_mtime since we don't
+	 * have the ability to represent them in our filesystem?
+	 */
+	if (ia_valid & ATTR_ATIME)
+		inode_set_atime_to_ts(inode, attr->ia_atime);
+	if (ia_valid & ATTR_CTIME)
+		inode_set_ctime_to_ts(inode, attr->ia_ctime);
+	if (ia_valid & ATTR_MODE) {
+		ADFS_I(inode)->attr = adfs_mode2atts(sb, inode, attr->ia_mode);
+		inode->i_mode = adfs_atts2mode(sb, inode);
+	}
+
+	/*
+	 * FIXME: should we be marking this inode dirty even if
+	 * we don't have any metadata to write back?
+	 */
+	if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE))
+		mark_inode_dirty(inode);
+out:
+	return error;
+}
+
+/*
+ * write an existing inode back to the directory, and therefore the disk.
+ * The adfs-specific inode data has already been updated by * adfs_setattr().
+ */
+int adfs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	struct super_block *sb = inode->i_sb;
+	struct object_info obj;
+
+	obj.indaddr	= ADFS_I(inode)->indaddr;
+	obj.name_len	= 0;
+	obj.parent_id	= ADFS_I(inode)->parent_id;
+	obj.loadaddr	= ADFS_I(inode)->loadaddr;
+	obj.execaddr	= ADFS_I(inode)->execaddr;
+	obj.attr	= ADFS_I(inode)->attr;
+	obj.size	= inode->i_size;
+
+	return adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL);
+}
diff --git a/fs/adfs/map.c b/fs/adfs/map.c
new file mode 100644
index 000000000..9d535a2ca
--- /dev/null
+++ b/fs/adfs/map.c
@@ -0,0 +1,407 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/adfs/map.c
+ *
+ *  Copyright (C) 1997-2002 Russell King
+ */
+#include <linux/slab.h>
+#include <linux/statfs.h>
+#include <linux/unaligned.h>
+#include "adfs.h"
+
+/*
+ * The ADFS map is basically a set of sectors.  Each sector is called a
+ * zone which contains a bitstream made up of variable sized fragments.
+ * Each bit refers to a set of bytes in the filesystem, defined by
+ * log2bpmb.  This may be larger or smaller than the sector size, but
+ * the overall size it describes will always be a round number of
+ * sectors.  A fragment id is always idlen bits long.
+ *
+ *  < idlen > <       n        > <1>
+ * +---------+-------//---------+---+
+ * | frag id |  0000....000000  | 1 |
+ * +---------+-------//---------+---+
+ *
+ * The physical disk space used by a fragment is taken from the start of
+ * the fragment id up to and including the '1' bit - ie, idlen + n + 1
+ * bits.
+ *
+ * A fragment id can be repeated multiple times in the whole map for
+ * large or fragmented files.  The first map zone a fragment starts in
+ * is given by fragment id / ids_per_zone - this allows objects to start
+ * from any zone on the disk.
+ *
+ * Free space is described by a linked list of fragments.  Each free
+ * fragment describes free space in the same way as the other fragments,
+ * however, the frag id specifies an offset (in map bits) from the end
+ * of this fragment to the start of the next free fragment.
+ *
+ * Objects stored on the disk are allocated object ids (we use these as
+ * our inode numbers.)  Object ids contain a fragment id and an optional
+ * offset.  This allows a directory fragment to contain small files
+ * associated with that directory.
+ */
+
+/*
+ * For the future...
+ */
+static DEFINE_RWLOCK(adfs_map_lock);
+
+/*
+ * This is fun.  We need to load up to 19 bits from the map at an
+ * arbitrary bit alignment.  (We're limited to 19 bits by F+ version 2).
+ */
+#define GET_FRAG_ID(_map,_start,_idmask)				\
+	({								\
+		unsigned char *_m = _map + (_start >> 3);		\
+		u32 _frag = get_unaligned_le32(_m);			\
+		_frag >>= (_start & 7);					\
+		_frag & _idmask;					\
+	})
+
+/*
+ * return the map bit offset of the fragment frag_id in the zone dm.
+ * Note that the loop is optimised for best asm code - look at the
+ * output of:
+ *  gcc -D__KERNEL__ -O2 -I../../include -o - -S map.c
+ */
+static int lookup_zone(const struct adfs_discmap *dm, const unsigned int idlen,
+		       const u32 frag_id, unsigned int *offset)
+{
+	const unsigned int endbit = dm->dm_endbit;
+	const u32 idmask = (1 << idlen) - 1;
+	unsigned char *map = dm->dm_bh->b_data;
+	unsigned int start = dm->dm_startbit;
+	unsigned int freelink, fragend;
+	u32 frag;
+
+	frag = GET_FRAG_ID(map, 8, idmask & 0x7fff);
+	freelink = frag ? 8 + frag : 0;
+
+	do {
+		frag = GET_FRAG_ID(map, start, idmask);
+
+		fragend = find_next_bit_le(map, endbit, start + idlen);
+		if (fragend >= endbit)
+			goto error;
+
+		if (start == freelink) {
+			freelink += frag & 0x7fff;
+		} else if (frag == frag_id) {
+			unsigned int length = fragend + 1 - start;
+
+			if (*offset < length)
+				return start + *offset;
+			*offset -= length;
+		}
+
+		start = fragend + 1;
+	} while (start < endbit);
+	return -1;
+
+error:
+	printk(KERN_ERR "adfs: oversized fragment 0x%x at 0x%x-0x%x\n",
+		frag, start, fragend);
+	return -1;
+}
+
+/*
+ * Scan the free space map, for this zone, calculating the total
+ * number of map bits in each free space fragment.
+ *
+ * Note: idmask is limited to 15 bits [3.2]
+ */
+static unsigned int
+scan_free_map(struct adfs_sb_info *asb, struct adfs_discmap *dm)
+{
+	const unsigned int endbit = dm->dm_endbit;
+	const unsigned int idlen  = asb->s_idlen;
+	const unsigned int frag_idlen = idlen <= 15 ? idlen : 15;
+	const u32 idmask = (1 << frag_idlen) - 1;
+	unsigned char *map = dm->dm_bh->b_data;
+	unsigned int start = 8, fragend;
+	u32 frag;
+	unsigned long total = 0;
+
+	/*
+	 * get fragment id
+	 */
+	frag = GET_FRAG_ID(map, start, idmask);
+
+	/*
+	 * If the freelink is null, then no free fragments
+	 * exist in this zone.
+	 */
+	if (frag == 0)
+		return 0;
+
+	do {
+		start += frag;
+
+		frag = GET_FRAG_ID(map, start, idmask);
+
+		fragend = find_next_bit_le(map, endbit, start + idlen);
+		if (fragend >= endbit)
+			goto error;
+
+		total += fragend + 1 - start;
+	} while (frag >= idlen + 1);
+
+	if (frag != 0)
+		printk(KERN_ERR "adfs: undersized free fragment\n");
+
+	return total;
+error:
+	printk(KERN_ERR "adfs: oversized free fragment\n");
+	return 0;
+}
+
+static int scan_map(struct adfs_sb_info *asb, unsigned int zone,
+		    const u32 frag_id, unsigned int mapoff)
+{
+	const unsigned int idlen = asb->s_idlen;
+	struct adfs_discmap *dm, *dm_end;
+	int result;
+
+	dm	= asb->s_map + zone;
+	zone	= asb->s_map_size;
+	dm_end	= asb->s_map + zone;
+
+	do {
+		result = lookup_zone(dm, idlen, frag_id, &mapoff);
+
+		if (result != -1)
+			goto found;
+
+		dm ++;
+		if (dm == dm_end)
+			dm = asb->s_map;
+	} while (--zone > 0);
+
+	return -1;
+found:
+	result -= dm->dm_startbit;
+	result += dm->dm_startblk;
+
+	return result;
+}
+
+/*
+ * calculate the amount of free blocks in the map.
+ *
+ *              n=1
+ *  total_free = E(free_in_zone_n)
+ *              nzones
+ */
+void adfs_map_statfs(struct super_block *sb, struct kstatfs *buf)
+{
+	struct adfs_sb_info *asb = ADFS_SB(sb);
+	struct adfs_discrecord *dr = adfs_map_discrecord(asb->s_map);
+	struct adfs_discmap *dm;
+	unsigned int total = 0;
+	unsigned int zone;
+
+	dm   = asb->s_map;
+	zone = asb->s_map_size;
+
+	do {
+		total += scan_free_map(asb, dm++);
+	} while (--zone > 0);
+
+	buf->f_blocks  = adfs_disc_size(dr) >> sb->s_blocksize_bits;
+	buf->f_files   = asb->s_ids_per_zone * asb->s_map_size;
+	buf->f_bavail  =
+	buf->f_bfree   = signed_asl(total, asb->s_map2blk);
+}
+
+int adfs_map_lookup(struct super_block *sb, u32 frag_id, unsigned int offset)
+{
+	struct adfs_sb_info *asb = ADFS_SB(sb);
+	unsigned int zone, mapoff;
+	int result;
+
+	/*
+	 * map & root fragment is special - it starts in the center of the
+	 * disk.  The other fragments start at zone (frag / ids_per_zone)
+	 */
+	if (frag_id == ADFS_ROOT_FRAG)
+		zone = asb->s_map_size >> 1;
+	else
+		zone = frag_id / asb->s_ids_per_zone;
+
+	if (zone >= asb->s_map_size)
+		goto bad_fragment;
+
+	/* Convert sector offset to map offset */
+	mapoff = signed_asl(offset, -asb->s_map2blk);
+
+	read_lock(&adfs_map_lock);
+	result = scan_map(asb, zone, frag_id, mapoff);
+	read_unlock(&adfs_map_lock);
+
+	if (result > 0) {
+		unsigned int secoff;
+
+		/* Calculate sector offset into map block */
+		secoff = offset - signed_asl(mapoff, asb->s_map2blk);
+		return secoff + signed_asl(result, asb->s_map2blk);
+	}
+
+	adfs_error(sb, "fragment 0x%04x at offset %d not found in map",
+		   frag_id, offset);
+	return 0;
+
+bad_fragment:
+	adfs_error(sb, "invalid fragment 0x%04x (zone = %d, max = %d)",
+		   frag_id, zone, asb->s_map_size);
+	return 0;
+}
+
+static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
+{
+	unsigned int v0, v1, v2, v3;
+	int i;
+
+	v0 = v1 = v2 = v3 = 0;
+	for (i = sb->s_blocksize - 4; i; i -= 4) {
+		v0 += map[i]     + (v3 >> 8);
+		v3 &= 0xff;
+		v1 += map[i + 1] + (v0 >> 8);
+		v0 &= 0xff;
+		v2 += map[i + 2] + (v1 >> 8);
+		v1 &= 0xff;
+		v3 += map[i + 3] + (v2 >> 8);
+		v2 &= 0xff;
+	}
+	v0 +=           v3 >> 8;
+	v1 += map[1] + (v0 >> 8);
+	v2 += map[2] + (v1 >> 8);
+	v3 += map[3] + (v2 >> 8);
+
+	return v0 ^ v1 ^ v2 ^ v3;
+}
+
+static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
+{
+	unsigned char crosscheck = 0, zonecheck = 1;
+	int i;
+
+	for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
+		unsigned char *map;
+
+		map = dm[i].dm_bh->b_data;
+
+		if (adfs_calczonecheck(sb, map) != map[0]) {
+			adfs_error(sb, "zone %d fails zonecheck", i);
+			zonecheck = 0;
+		}
+		crosscheck ^= map[3];
+	}
+	if (crosscheck != 0xff)
+		adfs_error(sb, "crosscheck != 0xff");
+	return crosscheck == 0xff && zonecheck;
+}
+
+/*
+ * Layout the map - the first zone contains a copy of the disc record,
+ * and the last zone must be limited to the size of the filesystem.
+ */
+static void adfs_map_layout(struct adfs_discmap *dm, unsigned int nzones,
+			    struct adfs_discrecord *dr)
+{
+	unsigned int zone, zone_size;
+	u64 size;
+
+	zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
+
+	dm[0].dm_bh       = NULL;
+	dm[0].dm_startblk = 0;
+	dm[0].dm_startbit = 32 + ADFS_DR_SIZE_BITS;
+	dm[0].dm_endbit   = 32 + zone_size;
+
+	for (zone = 1; zone < nzones; zone++) {
+		dm[zone].dm_bh       = NULL;
+		dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
+		dm[zone].dm_startbit = 32;
+		dm[zone].dm_endbit   = 32 + zone_size;
+	}
+
+	size = adfs_disc_size(dr) >> dr->log2bpmb;
+	size -= (nzones - 1) * zone_size - ADFS_DR_SIZE_BITS;
+	dm[nzones - 1].dm_endbit = 32 + size;
+}
+
+static int adfs_map_read(struct adfs_discmap *dm, struct super_block *sb,
+			 unsigned int map_addr, unsigned int nzones)
+{
+	unsigned int zone;
+
+	for (zone = 0; zone < nzones; zone++) {
+		dm[zone].dm_bh = sb_bread(sb, map_addr + zone);
+		if (!dm[zone].dm_bh)
+			return -EIO;
+	}
+
+	return 0;
+}
+
+static void adfs_map_relse(struct adfs_discmap *dm, unsigned int nzones)
+{
+	unsigned int zone;
+
+	for (zone = 0; zone < nzones; zone++)
+		brelse(dm[zone].dm_bh);
+}
+
+struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
+{
+	struct adfs_sb_info *asb = ADFS_SB(sb);
+	struct adfs_discmap *dm;
+	unsigned int map_addr, zone_size, nzones;
+	int ret;
+
+	nzones    = dr->nzones | dr->nzones_high << 8;
+	zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
+
+	asb->s_idlen = dr->idlen;
+	asb->s_map_size = nzones;
+	asb->s_map2blk = dr->log2bpmb - dr->log2secsize;
+	asb->s_log2sharesize = dr->log2sharesize;
+	asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
+
+	map_addr = (nzones >> 1) * zone_size -
+		     ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
+	map_addr = signed_asl(map_addr, asb->s_map2blk);
+
+	dm = kmalloc_objs(*dm, nzones);
+	if (dm == NULL) {
+		adfs_error(sb, "not enough memory");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	adfs_map_layout(dm, nzones, dr);
+
+	ret = adfs_map_read(dm, sb, map_addr, nzones);
+	if (ret) {
+		adfs_error(sb, "unable to read map");
+		goto error_free;
+	}
+
+	if (adfs_checkmap(sb, dm))
+		return dm;
+
+	adfs_error(sb, "map corrupted");
+
+error_free:
+	adfs_map_relse(dm, nzones);
+	kfree(dm);
+	return ERR_PTR(-EIO);
+}
+
+void adfs_free_map(struct super_block *sb)
+{
+	struct adfs_sb_info *asb = ADFS_SB(sb);
+
+	adfs_map_relse(asb->s_map, asb->s_map_size);
+	kfree(asb->s_map);
+}
diff --git a/fs/adfs/super.c b/fs/adfs/super.c
new file mode 100644
index 000000000..a4cd0a515
--- /dev/null
+++ b/fs/adfs/super.c
@@ -0,0 +1,502 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/adfs/super.c
+ *
+ *  Copyright (C) 1997-1999 Russell King
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs_parser.h>
+#include <linux/fs_context.h>
+#include <linux/mount.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/statfs.h>
+#include <linux/user_namespace.h>
+#include <linux/blkdev.h>
+#include "adfs.h"
+#include "dir_f.h"
+#include "dir_fplus.h"
+
+#define ADFS_SB_FLAGS SB_NOATIME
+
+#define ADFS_DEFAULT_OWNER_MASK S_IRWXU
+#define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
+
+void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n",
+		sb->s_id, function ? ": " : "",
+		function ? function : "", &vaf);
+
+	va_end(args);
+}
+
+void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf);
+	va_end(args);
+}
+
+static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
+{
+	unsigned int max_idlen;
+	int i;
+
+	/* sector size must be 256, 512 or 1024 bytes */
+	if (dr->log2secsize != 8 &&
+	    dr->log2secsize != 9 &&
+	    dr->log2secsize != 10)
+		return 1;
+
+	/* idlen must be at least log2secsize + 3 */
+	if (dr->idlen < dr->log2secsize + 3)
+		return 1;
+
+	/* we cannot have such a large disc that we
+	 * are unable to represent sector offsets in
+	 * 32 bits.  This works out at 2.0 TB.
+	 */
+	if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
+		return 1;
+
+	/*
+	 * Maximum idlen is limited to 16 bits for new directories by
+	 * the three-byte storage of an indirect disc address.  For
+	 * big directories, idlen must be no greater than 19 v2 [1.0]
+	 */
+	max_idlen = dr->format_version ? 19 : 16;
+	if (dr->idlen > max_idlen)
+		return 1;
+
+	/* reserved bytes should be zero */
+	for (i = 0; i < sizeof(dr->unused52); i++)
+		if (dr->unused52[i] != 0)
+			return 1;
+
+	return 0;
+}
+
+static void adfs_put_super(struct super_block *sb)
+{
+	struct adfs_sb_info *asb = ADFS_SB(sb);
+
+	adfs_free_map(sb);
+	kfree_rcu(asb, rcu);
+}
+
+static int adfs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
+
+	if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID))
+		seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
+	if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
+		seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
+	if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
+		seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
+	if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
+		seq_printf(seq, ",othmask=%o", asb->s_other_mask);
+	if (asb->s_ftsuffix != 0)
+		seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
+
+	return 0;
+}
+
+enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix};
+
+static const struct fs_parameter_spec adfs_param_spec[] = {
+	fsparam_uid	("uid",		Opt_uid),
+	fsparam_gid	("gid",		Opt_gid),
+	fsparam_u32oct	("ownmask",	Opt_ownmask),
+	fsparam_u32oct	("othmask",	Opt_othmask),
+	fsparam_u32	("ftsuffix",	Opt_ftsuffix),
+	{}
+};
+
+static int adfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct adfs_sb_info *asb = fc->s_fs_info;
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, adfs_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_uid:
+		asb->s_uid = result.uid;
+		break;
+	case Opt_gid:
+		asb->s_gid = result.gid;
+		break;
+	case Opt_ownmask:
+		asb->s_owner_mask = result.uint_32;
+		break;
+	case Opt_othmask:
+		asb->s_other_mask = result.uint_32;
+		break;
+	case Opt_ftsuffix:
+		asb->s_ftsuffix = result.uint_32;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int adfs_reconfigure(struct fs_context *fc)
+{
+	struct adfs_sb_info *new_asb = fc->s_fs_info;
+	struct adfs_sb_info *asb = ADFS_SB(fc->root->d_sb);
+
+	sync_filesystem(fc->root->d_sb);
+	fc->sb_flags |= ADFS_SB_FLAGS;
+
+	/* Structure copy newly parsed options */
+	*asb = *new_asb;
+
+	return 0;
+}
+
+static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct adfs_sb_info *sbi = ADFS_SB(sb);
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+	adfs_map_statfs(sb, buf);
+
+	buf->f_type    = ADFS_SUPER_MAGIC;
+	buf->f_namelen = sbi->s_namelen;
+	buf->f_bsize   = sb->s_blocksize;
+	buf->f_ffree   = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
+	buf->f_fsid    = u64_to_fsid(id);
+
+	return 0;
+}
+
+static struct kmem_cache *adfs_inode_cachep;
+
+static struct inode *adfs_alloc_inode(struct super_block *sb)
+{
+	struct adfs_inode_info *ei;
+	ei = alloc_inode_sb(sb, adfs_inode_cachep, GFP_KERNEL);
+	if (!ei)
+		return NULL;
+	return &ei->vfs_inode;
+}
+
+static void adfs_free_inode(struct inode *inode)
+{
+	kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
+}
+
+static int adfs_drop_inode(struct inode *inode)
+{
+	/* always drop inodes if we are read-only */
+	return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode);
+}
+
+static void init_once(void *foo)
+{
+	struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
+
+	inode_init_once(&ei->vfs_inode);
+}
+
+static int __init init_inodecache(void)
+{
+	adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
+					     sizeof(struct adfs_inode_info),
+					     0, (SLAB_RECLAIM_ACCOUNT|
+						SLAB_ACCOUNT),
+					     init_once);
+	if (adfs_inode_cachep == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
+static void destroy_inodecache(void)
+{
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(adfs_inode_cachep);
+}
+
+static const struct super_operations adfs_sops = {
+	.alloc_inode	= adfs_alloc_inode,
+	.free_inode	= adfs_free_inode,
+	.drop_inode	= adfs_drop_inode,
+	.write_inode	= adfs_write_inode,
+	.put_super	= adfs_put_super,
+	.statfs		= adfs_statfs,
+	.show_options	= adfs_show_options,
+};
+
+static int adfs_probe(struct super_block *sb, unsigned int offset, int silent,
+		      int (*validate)(struct super_block *sb,
+				      struct buffer_head *bh,
+				      struct adfs_discrecord **bhp))
+{
+	struct adfs_sb_info *asb = ADFS_SB(sb);
+	struct adfs_discrecord *dr;
+	struct buffer_head *bh;
+	unsigned int blocksize = BLOCK_SIZE;
+	int ret, try;
+
+	for (try = 0; try < 2; try++) {
+		/* try to set the requested block size */
+		if (sb->s_blocksize != blocksize &&
+		    !sb_set_blocksize(sb, blocksize)) {
+			if (!silent)
+				adfs_msg(sb, KERN_ERR,
+					 "error: unsupported blocksize");
+			return -EINVAL;
+		}
+
+		/* read the buffer */
+		bh = sb_bread(sb, offset >> sb->s_blocksize_bits);
+		if (!bh) {
+			adfs_msg(sb, KERN_ERR,
+				 "error: unable to read block %u, try %d",
+				 offset >> sb->s_blocksize_bits, try);
+			return -EIO;
+		}
+
+		/* validate it */
+		ret = validate(sb, bh, &dr);
+		if (ret) {
+			brelse(bh);
+			return ret;
+		}
+
+		/* does the block size match the filesystem block size? */
+		blocksize = 1 << dr->log2secsize;
+		if (sb->s_blocksize == blocksize) {
+			asb->s_map = adfs_read_map(sb, dr);
+			brelse(bh);
+			return PTR_ERR_OR_ZERO(asb->s_map);
+		}
+
+		brelse(bh);
+	}
+
+	return -EIO;
+}
+
+static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh,
+			      struct adfs_discrecord **drp)
+{
+	struct adfs_discrecord *dr;
+	unsigned char *b_data;
+
+	b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
+	if (adfs_checkbblk(b_data))
+		return -EILSEQ;
+
+	/* Do some sanity checks on the ADFS disc record */
+	dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
+	if (adfs_checkdiscrecord(dr))
+		return -EILSEQ;
+
+	if ((dr->nzones | dr->nzones_high << 8) == 0)
+		return -EILSEQ;
+
+	*drp = dr;
+	return 0;
+}
+
+static int adfs_validate_dr0(struct super_block *sb, struct buffer_head *bh,
+			      struct adfs_discrecord **drp)
+{
+	struct adfs_discrecord *dr;
+
+	/* Do some sanity checks on the ADFS disc record */
+	dr = (struct adfs_discrecord *)(bh->b_data + 4);
+	if (adfs_checkdiscrecord(dr) || dr->nzones_high || dr->nzones != 1)
+		return -EILSEQ;
+
+	*drp = dr;
+	return 0;
+}
+
+static int adfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct adfs_discrecord *dr;
+	struct object_info root_obj;
+	struct adfs_sb_info *asb = sb->s_fs_info;
+	struct inode *root;
+	int ret = -EINVAL;
+	int silent = fc->sb_flags & SB_SILENT;
+
+	sb->s_flags |= ADFS_SB_FLAGS;
+
+	sb->s_fs_info = asb;
+	sb->s_magic = ADFS_SUPER_MAGIC;
+	sb->s_time_gran = 10000000;
+
+	/* Try to probe the filesystem boot block */
+	ret = adfs_probe(sb, ADFS_DISCRECORD, 1, adfs_validate_bblk);
+	if (ret == -EILSEQ)
+		ret = adfs_probe(sb, 0, silent, adfs_validate_dr0);
+	if (ret == -EILSEQ) {
+		if (!silent)
+			adfs_msg(sb, KERN_ERR,
+				 "error: can't find an ADFS filesystem on dev %s.",
+				 sb->s_id);
+		ret = -EINVAL;
+	}
+	if (ret)
+		goto error;
+
+	/* set up enough so that we can read an inode */
+	sb->s_op = &adfs_sops;
+
+	dr = adfs_map_discrecord(asb->s_map);
+
+	root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root);
+	root_obj.name_len  = 0;
+	/* Set root object date as 01 Jan 1987 00:00:00 */
+	root_obj.loadaddr  = 0xfff0003f;
+	root_obj.execaddr  = 0xec22c000;
+	root_obj.size	   = ADFS_NEWDIR_SIZE;
+	root_obj.attr	   = ADFS_NDA_DIRECTORY   | ADFS_NDA_OWNER_READ |
+			     ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
+
+	/*
+	 * If this is a F+ disk with variable length directories,
+	 * get the root_size from the disc record.
+	 */
+	if (dr->format_version) {
+		root_obj.size = le32_to_cpu(dr->root_size);
+		asb->s_dir     = &adfs_fplus_dir_ops;
+		asb->s_namelen = ADFS_FPLUS_NAME_LEN;
+	} else {
+		asb->s_dir     = &adfs_f_dir_ops;
+		asb->s_namelen = ADFS_F_NAME_LEN;
+	}
+	/*
+	 * ,xyz hex filetype suffix may be added by driver
+	 * to files that have valid RISC OS filetype
+	 */
+	if (asb->s_ftsuffix)
+		asb->s_namelen += 4;
+
+	set_default_d_op(sb, &adfs_dentry_operations);
+	root = adfs_iget(sb, &root_obj);
+	sb->s_root = d_make_root(root);
+	if (!sb->s_root) {
+		adfs_free_map(sb);
+		adfs_error(sb, "get root inode failed\n");
+		ret = -EIO;
+		goto error;
+	}
+	return 0;
+
+error:
+	sb->s_fs_info = NULL;
+	kfree(asb);
+	return ret;
+}
+
+static int adfs_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, adfs_fill_super);
+}
+
+static void adfs_free_fc(struct fs_context *fc)
+{
+	struct adfs_context *asb = fc->s_fs_info;
+
+	kfree(asb);
+}
+
+static const struct fs_context_operations adfs_context_ops = {
+	.parse_param	= adfs_parse_param,
+	.get_tree	= adfs_get_tree,
+	.reconfigure	= adfs_reconfigure,
+	.free		= adfs_free_fc,
+};
+
+static int adfs_init_fs_context(struct fs_context *fc)
+{
+	struct adfs_sb_info *asb;
+
+	asb = kzalloc_obj(struct adfs_sb_info);
+	if (!asb)
+		return -ENOMEM;
+
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
+		struct super_block *sb = fc->root->d_sb;
+		struct adfs_sb_info *old_asb = ADFS_SB(sb);
+
+		/* structure copy existing options before parsing */
+		*asb = *old_asb;
+	} else {
+		/* set default options */
+		asb->s_uid = GLOBAL_ROOT_UID;
+		asb->s_gid = GLOBAL_ROOT_GID;
+		asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
+		asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
+		asb->s_ftsuffix = 0;
+	}
+
+	fc->ops = &adfs_context_ops;
+	fc->s_fs_info = asb;
+
+	return 0;
+}
+
+static struct file_system_type adfs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "adfs",
+	.kill_sb	= kill_block_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+	.init_fs_context = adfs_init_fs_context,
+	.parameters	= adfs_param_spec,
+};
+MODULE_ALIAS_FS("adfs");
+
+static int __init init_adfs_fs(void)
+{
+	int err = init_inodecache();
+	if (err)
+		goto out1;
+	err = register_filesystem(&adfs_fs_type);
+	if (err)
+		goto out;
+	return 0;
+out:
+	destroy_inodecache();
+out1:
+	return err;
+}
+
+static void __exit exit_adfs_fs(void)
+{
+	unregister_filesystem(&adfs_fs_type);
+	destroy_inodecache();
+}
+
+module_init(init_adfs_fs)
+module_exit(exit_adfs_fs)
+MODULE_DESCRIPTION("Acorn Disc Filing System");
+MODULE_LICENSE("GPL");