selftests/bpf: Add a test for objects stuck in free_by_rcu_ttracegrafted

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first
free_bulk() starts RCU tasks trace GP and the rest of the elements are
freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear
in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and
waiting_for_gp_ttrace lists are empty.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

23 files changed, 6542 insertions, 0 deletions

diff --git a/fs/hfs/.kunitconfig b/fs/hfs/.kunitconfig
new file mode 100644
index 000000000..5caa9af1e
--- /dev/null
+++ b/fs/hfs/.kunitconfig
@@ -0,0 +1,7 @@
+CONFIG_KUNIT=y
+CONFIG_HFS_FS=y
+CONFIG_HFS_KUNIT_TEST=y
+CONFIG_BLOCK=y
+CONFIG_BUFFER_HEAD=y
+CONFIG_NLS=y
+CONFIG_LEGACY_DIRECT_IO=y
diff --git a/fs/hfs/Kconfig b/fs/hfs/Kconfig
new file mode 100644
index 000000000..7f3cbe43b
--- /dev/null
+++ b/fs/hfs/Kconfig
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config HFS_FS
+	tristate "Apple Macintosh file system support"
+	depends on BLOCK
+	select BUFFER_HEAD
+	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.
+	  Please read <file:Documentation/filesystems/hfs.rst> to learn about
+	  the available mount options.
+
+	  To compile this file system support as a module, choose M here: the
+	  module will be called hfs.
+
+config HFS_KUNIT_TEST
+	tristate "KUnit tests for HFS filesystem" if !KUNIT_ALL_TESTS
+	depends on HFS_FS && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This builds KUnit tests for the HFS filesystem.
+
+	  KUnit tests run during boot and output the results to the debug
+	  log in TAP format (https://testanything.org/). Only useful for
+	  kernel devs running KUnit test harness and are not for inclusion
+	  into a production build.
+
+	  For more information on KUnit and unit tests in general please
+	  refer to the KUnit documentation in Documentation/dev-tools/kunit/.
diff --git a/fs/hfs/Makefile b/fs/hfs/Makefile
new file mode 100644
index 000000000..a7c9ce6b4
--- /dev/null
+++ b/fs/hfs/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the Linux hfs filesystem routines.
+#
+
+obj-$(CONFIG_HFS_FS) += hfs.o
+
+hfs-objs := bitmap.o bfind.o bnode.o brec.o btree.o \
+	    catalog.o dir.o extent.o inode.o attr.o mdb.o \
+            part_tbl.o string.o super.o sysdep.o trans.o
+
+# KUnit tests
+obj-$(CONFIG_HFS_KUNIT_TEST) += string_test.o
diff --git a/fs/hfs/attr.c b/fs/hfs/attr.c
new file mode 100644
index 000000000..f8395cdd1
--- /dev/null
+++ b/fs/hfs/attr.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hfs/attr.c
+ *
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Export hfs data via xattr
+ */
+
+
+#include <linux/fs.h>
+#include <linux/xattr.h>
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+enum hfs_xattr_type {
+	HFS_TYPE,
+	HFS_CREATOR,
+};
+
+static int __hfs_setxattr(struct inode *inode, enum hfs_xattr_type type,
+			  const void *value, size_t size, int flags)
+{
+	struct hfs_find_data fd;
+	hfs_cat_rec rec;
+	struct hfs_cat_file *file;
+	int res;
+
+	if (!S_ISREG(inode->i_mode) || HFS_IS_RSRC(inode))
+		return -EOPNOTSUPP;
+
+	res = hfs_find_init(HFS_SB(inode->i_sb)->cat_tree, &fd);
+	if (res)
+		return res;
+	fd.search_key->cat = HFS_I(inode)->cat_key;
+	res = hfs_brec_find(&fd);
+	if (res)
+		goto out;
+	hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
+			sizeof(struct hfs_cat_file));
+	file = &rec.file;
+
+	switch (type) {
+	case HFS_TYPE:
+		if (size == 4)
+			memcpy(&file->UsrWds.fdType, value, 4);
+		else
+			res = -ERANGE;
+		break;
+
+	case HFS_CREATOR:
+		if (size == 4)
+			memcpy(&file->UsrWds.fdCreator, value, 4);
+		else
+			res = -ERANGE;
+		break;
+	}
+
+	if (!res)
+		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
+				sizeof(struct hfs_cat_file));
+out:
+	hfs_find_exit(&fd);
+	return res;
+}
+
+static ssize_t __hfs_getxattr(struct inode *inode, enum hfs_xattr_type type,
+			      void *value, size_t size)
+{
+	struct hfs_find_data fd;
+	hfs_cat_rec rec;
+	struct hfs_cat_file *file;
+	ssize_t res = 0;
+
+	if (!S_ISREG(inode->i_mode) || HFS_IS_RSRC(inode))
+		return -EOPNOTSUPP;
+
+	if (size) {
+		res = hfs_find_init(HFS_SB(inode->i_sb)->cat_tree, &fd);
+		if (res)
+			return res;
+		fd.search_key->cat = HFS_I(inode)->cat_key;
+		res = hfs_brec_find(&fd);
+		if (res)
+			goto out;
+		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
+				sizeof(struct hfs_cat_file));
+	}
+	file = &rec.file;
+
+	switch (type) {
+	case HFS_TYPE:
+		if (size >= 4) {
+			memcpy(value, &file->UsrWds.fdType, 4);
+			res = 4;
+		} else
+			res = size ? -ERANGE : 4;
+		break;
+
+	case HFS_CREATOR:
+		if (size >= 4) {
+			memcpy(value, &file->UsrWds.fdCreator, 4);
+			res = 4;
+		} else
+			res = size ? -ERANGE : 4;
+		break;
+	}
+
+out:
+	if (size)
+		hfs_find_exit(&fd);
+	return res;
+}
+
+static int hfs_xattr_get(const struct xattr_handler *handler,
+			 struct dentry *unused, struct inode *inode,
+			 const char *name, void *value, size_t size)
+{
+	return __hfs_getxattr(inode, handler->flags, value, size);
+}
+
+static int hfs_xattr_set(const struct xattr_handler *handler,
+			 struct mnt_idmap *idmap,
+			 struct dentry *unused, struct inode *inode,
+			 const char *name, const void *value, size_t size,
+			 int flags)
+{
+	if (!value)
+		return -EOPNOTSUPP;
+
+	return __hfs_setxattr(inode, handler->flags, value, size, flags);
+}
+
+static const struct xattr_handler hfs_creator_handler = {
+	.name = "hfs.creator",
+	.flags = HFS_CREATOR,
+	.get = hfs_xattr_get,
+	.set = hfs_xattr_set,
+};
+
+static const struct xattr_handler hfs_type_handler = {
+	.name = "hfs.type",
+	.flags = HFS_TYPE,
+	.get = hfs_xattr_get,
+	.set = hfs_xattr_set,
+};
+
+const struct xattr_handler * const hfs_xattr_handlers[] = {
+	&hfs_creator_handler,
+	&hfs_type_handler,
+	NULL
+};
diff --git a/fs/hfs/bfind.c b/fs/hfs/bfind.c
new file mode 100644
index 000000000..d56e47bdc
--- /dev/null
+++ b/fs/hfs/bfind.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hfs/bfind.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Search routines for btrees
+ */
+
+#include <linux/slab.h>
+#include "btree.h"
+
+int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
+{
+	void *ptr;
+
+	if (!tree || !fd)
+		return -EINVAL;
+
+	fd->tree = tree;
+	fd->bnode = NULL;
+	ptr = kzalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+	fd->search_key = ptr;
+	fd->key = ptr + tree->max_key_len + 2;
+	hfs_dbg("cnid %d, caller %ps\n",
+		tree->cnid, __builtin_return_address(0));
+	switch (tree->cnid) {
+	case HFS_CAT_CNID:
+		mutex_lock_nested(&tree->tree_lock, CATALOG_BTREE_MUTEX);
+		break;
+	case HFS_EXT_CNID:
+		mutex_lock_nested(&tree->tree_lock, EXTENTS_BTREE_MUTEX);
+		break;
+	case HFS_ATTR_CNID:
+		mutex_lock_nested(&tree->tree_lock, ATTR_BTREE_MUTEX);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+void hfs_find_exit(struct hfs_find_data *fd)
+{
+	hfs_bnode_put(fd->bnode);
+	kfree(fd->search_key);
+	hfs_dbg("cnid %d, caller %ps\n",
+		fd->tree->cnid, __builtin_return_address(0));
+	mutex_unlock(&fd->tree->tree_lock);
+	fd->tree = NULL;
+}
+
+/* Find the record in bnode that best matches key (not greater than...)*/
+int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd)
+{
+	int cmpval;
+	u16 off, len, keylen;
+	int rec;
+	int b, e;
+	int res;
+
+	b = 0;
+	e = bnode->num_recs - 1;
+	res = -ENOENT;
+	do {
+		rec = (e + b) / 2;
+		len = hfs_brec_lenoff(bnode, rec, &off);
+		keylen = hfs_brec_keylen(bnode, rec);
+		if (keylen == 0) {
+			res = -EINVAL;
+			goto fail;
+		}
+		hfs_bnode_read(bnode, fd->key, off, keylen);
+		cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
+		if (!cmpval) {
+			e = rec;
+			res = 0;
+			goto done;
+		}
+		if (cmpval < 0)
+			b = rec + 1;
+		else
+			e = rec - 1;
+	} while (b <= e);
+	if (rec != e && e >= 0) {
+		len = hfs_brec_lenoff(bnode, e, &off);
+		keylen = hfs_brec_keylen(bnode, e);
+		if (keylen == 0) {
+			res = -EINVAL;
+			goto fail;
+		}
+		hfs_bnode_read(bnode, fd->key, off, keylen);
+	}
+done:
+	fd->record = e;
+	fd->keyoffset = off;
+	fd->keylength = keylen;
+	fd->entryoffset = off + keylen;
+	fd->entrylength = len - keylen;
+fail:
+	return res;
+}
+
+/* Traverse a B*Tree from the root to a leaf finding best fit to key */
+/* Return allocated copy of node found, set recnum to best record */
+int hfs_brec_find(struct hfs_find_data *fd)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *bnode;
+	u32 nidx, parent;
+	__be32 data;
+	int height, res;
+
+	fd->record = -1;
+	fd->keyoffset = -1;
+	fd->keylength = -1;
+	fd->entryoffset = -1;
+	fd->entrylength = -1;
+
+	tree = fd->tree;
+	if (fd->bnode)
+		hfs_bnode_put(fd->bnode);
+	fd->bnode = NULL;
+	nidx = tree->root;
+	if (!nidx)
+		return -ENOENT;
+	height = tree->depth;
+	res = 0;
+	parent = 0;
+	for (;;) {
+		bnode = hfs_bnode_find(tree, nidx);
+		if (IS_ERR(bnode)) {
+			res = PTR_ERR(bnode);
+			bnode = NULL;
+			break;
+		}
+		if (bnode->height != height)
+			goto invalid;
+		if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
+			goto invalid;
+		bnode->parent = parent;
+
+		res = __hfs_brec_find(bnode, fd);
+		if (!height)
+			break;
+		if (fd->record < 0)
+			goto release;
+
+		parent = nidx;
+		hfs_bnode_read(bnode, &data, fd->entryoffset, 4);
+		nidx = be32_to_cpu(data);
+		hfs_bnode_put(bnode);
+	}
+	fd->bnode = bnode;
+	return res;
+
+invalid:
+	pr_err("inconsistency in B*Tree (%d,%d,%d,%u,%u)\n",
+	       height, bnode->height, bnode->type, nidx, parent);
+	res = -EIO;
+release:
+	hfs_bnode_put(bnode);
+	return res;
+}
+
+int hfs_brec_read(struct hfs_find_data *fd, void *rec, u32 rec_len)
+{
+	int res;
+
+	res = hfs_brec_find(fd);
+	if (res)
+		return res;
+	if (fd->entrylength > rec_len)
+		return -EINVAL;
+	hfs_bnode_read(fd->bnode, rec, fd->entryoffset, fd->entrylength);
+	return 0;
+}
+
+int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *bnode;
+	int idx, res = 0;
+	u16 off, len, keylen;
+
+	bnode = fd->bnode;
+	tree = bnode->tree;
+
+	if (cnt < 0) {
+		cnt = -cnt;
+		while (cnt > fd->record) {
+			cnt -= fd->record + 1;
+			fd->record = bnode->num_recs - 1;
+			idx = bnode->prev;
+			if (!idx) {
+				res = -ENOENT;
+				goto out;
+			}
+			hfs_bnode_put(bnode);
+			bnode = hfs_bnode_find(tree, idx);
+			if (IS_ERR(bnode)) {
+				res = PTR_ERR(bnode);
+				bnode = NULL;
+				goto out;
+			}
+		}
+		fd->record -= cnt;
+	} else {
+		while (cnt >= bnode->num_recs - fd->record) {
+			cnt -= bnode->num_recs - fd->record;
+			fd->record = 0;
+			idx = bnode->next;
+			if (!idx) {
+				res = -ENOENT;
+				goto out;
+			}
+			hfs_bnode_put(bnode);
+			bnode = hfs_bnode_find(tree, idx);
+			if (IS_ERR(bnode)) {
+				res = PTR_ERR(bnode);
+				bnode = NULL;
+				goto out;
+			}
+		}
+		fd->record += cnt;
+	}
+
+	len = hfs_brec_lenoff(bnode, fd->record, &off);
+	keylen = hfs_brec_keylen(bnode, fd->record);
+	if (keylen == 0) {
+		res = -EINVAL;
+		goto out;
+	}
+	fd->keyoffset = off;
+	fd->keylength = keylen;
+	fd->entryoffset = off + keylen;
+	fd->entrylength = len - keylen;
+	hfs_bnode_read(bnode, fd->key, off, keylen);
+out:
+	fd->bnode = bnode;
+	return res;
+}
diff --git a/fs/hfs/bitmap.c b/fs/hfs/bitmap.c
new file mode 100644
index 000000000..5e84833a4
--- /dev/null
+++ b/fs/hfs/bitmap.c
@@ -0,0 +1,243 @@
+/*
+ *  linux/fs/hfs/bitmap.c
+ *
+ * Copyright (C) 1996-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * Based on GPLed code Copyright (C) 1995  Michael Dreher
+ *
+ * This file contains the code to modify the volume bitmap:
+ * search/set/clear bits.
+ */
+
+#include "hfs_fs.h"
+
+/*
+ * hfs_find_zero_bit()
+ *
+ * Description:
+ *  Given a block of memory, its length in bits, and a starting bit number,
+ *  determine the number of the first zero bits (in left-to-right ordering)
+ *  in that range.
+ *
+ *  Returns >= 'size' if no zero bits are found in the range.
+ *
+ *  Accesses memory in 32-bit aligned chunks of 32-bits and thus
+ *  may read beyond the 'size'th bit.
+ */
+static u32 hfs_find_set_zero_bits(__be32 *bitmap, u32 size, u32 offset, u32 *max)
+{
+	__be32 *curr, *end;
+	u32 mask, start, len, n;
+	__be32 val;
+	int i;
+
+	len = *max;
+	if (!len)
+		return size;
+
+	curr = bitmap + (offset / 32);
+	end = bitmap + ((size + 31) / 32);
+
+	/* scan the first partial u32 for zero bits */
+	val = *curr;
+	if (~val) {
+		n = be32_to_cpu(val);
+		i = offset % 32;
+		mask = (1U << 31) >> i;
+		for (; i < 32; mask >>= 1, i++) {
+			if (!(n & mask))
+				goto found;
+		}
+	}
+
+	/* scan complete u32s for the first zero bit */
+	while (++curr < end) {
+		val = *curr;
+		if (~val) {
+			n = be32_to_cpu(val);
+			mask = 1 << 31;
+			for (i = 0; i < 32; mask >>= 1, i++) {
+				if (!(n & mask))
+					goto found;
+			}
+		}
+	}
+	return size;
+
+found:
+	start = (curr - bitmap) * 32 + i;
+	if (start >= size)
+		return start;
+	/* do any partial u32 at the start */
+	len = min(size - start, len);
+	while (1) {
+		n |= mask;
+		if (++i >= 32)
+			break;
+		mask >>= 1;
+		if (!--len || n & mask)
+			goto done;
+	}
+	if (!--len)
+		goto done;
+	*curr++ = cpu_to_be32(n);
+	/* do full u32s */
+	while (1) {
+		n = be32_to_cpu(*curr);
+		if (len < 32)
+			break;
+		if (n) {
+			len = 32;
+			break;
+		}
+		*curr++ = cpu_to_be32(0xffffffff);
+		len -= 32;
+	}
+	/* do any partial u32 at end */
+	mask = 1U << 31;
+	for (i = 0; i < len; i++) {
+		if (n & mask)
+			break;
+		n |= mask;
+		mask >>= 1;
+	}
+done:
+	*curr = cpu_to_be32(n);
+	*max = (curr - bitmap) * 32 + i - start;
+	return start;
+}
+
+/*
+ * hfs_vbm_search_free()
+ *
+ * Description:
+ *   Search for 'num_bits' consecutive cleared bits in the bitmap blocks of
+ *   the hfs MDB. 'mdb' had better be locked or the returned range
+ *   may be no longer free, when this functions returns!
+ *   XXX Currently the search starts from bit 0, but it should start with
+ *   the bit number stored in 's_alloc_ptr' of the MDB.
+ * Input Variable(s):
+ *   struct hfs_mdb *mdb: Pointer to the hfs MDB
+ *   u16 *num_bits: Pointer to the number of cleared bits
+ *     to search for
+ * Output Variable(s):
+ *   u16 *num_bits: The number of consecutive clear bits of the
+ *     returned range. If the bitmap is fragmented, this will be less than
+ *     requested and it will be zero, when the disk is full.
+ * Returns:
+ *   The number of the first bit of the range of cleared bits which has been
+ *   found. When 'num_bits' is zero, this is invalid!
+ * Preconditions:
+ *   'mdb' points to a "valid" (struct hfs_mdb).
+ *   'num_bits' points to a variable of type (u16), which contains
+ *	the number of cleared bits to find.
+ * Postconditions:
+ *   'num_bits' is set to the length of the found sequence.
+ */
+u32 hfs_vbm_search_free(struct super_block *sb, u32 goal, u32 *num_bits)
+{
+	void *bitmap;
+	u32 pos;
+
+	/* make sure we have actual work to perform */
+	if (!*num_bits)
+		return 0;
+
+	mutex_lock(&HFS_SB(sb)->bitmap_lock);
+	bitmap = HFS_SB(sb)->bitmap;
+
+	pos = hfs_find_set_zero_bits(bitmap, HFS_SB(sb)->fs_ablocks, goal, num_bits);
+	if (pos >= HFS_SB(sb)->fs_ablocks) {
+		if (goal)
+			pos = hfs_find_set_zero_bits(bitmap, goal, 0, num_bits);
+		if (pos >= HFS_SB(sb)->fs_ablocks) {
+			*num_bits = pos = 0;
+			goto out;
+		}
+	}
+
+	hfs_dbg("pos %u, num_bits %u\n", pos, *num_bits);
+	HFS_SB(sb)->free_ablocks -= *num_bits;
+	hfs_bitmap_dirty(sb);
+out:
+	mutex_unlock(&HFS_SB(sb)->bitmap_lock);
+	return pos;
+}
+
+
+/*
+ * hfs_clear_vbm_bits()
+ *
+ * Description:
+ *   Clear the requested bits in the volume bitmap of the hfs filesystem
+ * Input Variable(s):
+ *   struct hfs_mdb *mdb: Pointer to the hfs MDB
+ *   u16 start: The offset of the first bit
+ *   u16 count: The number of bits
+ * Output Variable(s):
+ *   None
+ * Returns:
+ *    0: no error
+ *   -1: One of the bits was already clear.  This is a strange
+ *	 error and when it happens, the filesystem must be repaired!
+ *   -2: One or more of the bits are out of range of the bitmap.
+ * Preconditions:
+ *   'mdb' points to a "valid" (struct hfs_mdb).
+ * Postconditions:
+ *   Starting with bit number 'start', 'count' bits in the volume bitmap
+ *   are cleared. The affected bitmap blocks are marked "dirty", the free
+ *   block count of the MDB is updated and the MDB is marked dirty.
+ */
+int hfs_clear_vbm_bits(struct super_block *sb, u16 start, u16 count)
+{
+	__be32 *curr;
+	u32 mask;
+	int i, len;
+
+	/* is there any actual work to be done? */
+	if (!count)
+		return 0;
+
+	hfs_dbg("start %u, count %u\n", start, count);
+	/* are all of the bits in range? */
+	if ((start + count) > HFS_SB(sb)->fs_ablocks)
+		return -2;
+
+	mutex_lock(&HFS_SB(sb)->bitmap_lock);
+	/* bitmap is always on a 32-bit boundary */
+	curr = HFS_SB(sb)->bitmap + (start / 32);
+	len = count;
+
+	/* do any partial u32 at the start */
+	i = start % 32;
+	if (i) {
+		int j = 32 - i;
+		mask = 0xffffffffU << j;
+		if (j > count) {
+			mask |= 0xffffffffU >> (i + count);
+			*curr &= cpu_to_be32(mask);
+			goto out;
+		}
+		*curr++ &= cpu_to_be32(mask);
+		count -= j;
+	}
+
+	/* do full u32s */
+	while (count >= 32) {
+		*curr++ = 0;
+		count -= 32;
+	}
+	/* do any partial u32 at end */
+	if (count) {
+		mask = 0xffffffffU >> count;
+		*curr &= cpu_to_be32(mask);
+	}
+out:
+	HFS_SB(sb)->free_ablocks += len;
+	mutex_unlock(&HFS_SB(sb)->bitmap_lock);
+	hfs_bitmap_dirty(sb);
+
+	return 0;
+}
diff --git a/fs/hfs/bnode.c b/fs/hfs/bnode.c
new file mode 100644
index 000000000..fcb5b9cd1
--- /dev/null
+++ b/fs/hfs/bnode.c
@@ -0,0 +1,542 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hfs/bnode.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handle basic btree node operations
+ */
+
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+
+#include "btree.h"
+
+void hfs_bnode_read(struct hfs_bnode *node, void *buf, u32 off, u32 len)
+{
+	struct page *page;
+	u32 pagenum;
+	u32 bytes_read;
+	u32 bytes_to_read;
+
+	memset(buf, 0, len);
+
+	if (!is_bnode_offset_valid(node, off))
+		return;
+
+	if (len == 0) {
+		pr_err("requested zero length: "
+		       "NODE: id %u, type %#x, height %u, "
+		       "node_size %u, offset %u, len %u\n",
+		       node->this, node->type, node->height,
+		       node->tree->node_size, off, len);
+		return;
+	}
+
+	len = check_and_correct_requested_length(node, off, len);
+
+	off += node->page_offset;
+	pagenum = off >> PAGE_SHIFT;
+	off &= ~PAGE_MASK; /* compute page offset for the first page */
+
+	for (bytes_read = 0; bytes_read < len; bytes_read += bytes_to_read) {
+		if (pagenum >= node->tree->pages_per_bnode)
+			break;
+		page = node->page[pagenum];
+		bytes_to_read = min_t(u32, len - bytes_read, PAGE_SIZE - off);
+
+		memcpy_from_page(buf + bytes_read, page, off, bytes_to_read);
+
+		pagenum++;
+		off = 0; /* page offset only applies to the first page */
+	}
+}
+
+u16 hfs_bnode_read_u16(struct hfs_bnode *node, u32 off)
+{
+	__be16 data;
+	// optimize later...
+	hfs_bnode_read(node, &data, off, 2);
+	return be16_to_cpu(data);
+}
+
+u8 hfs_bnode_read_u8(struct hfs_bnode *node, u32 off)
+{
+	u8 data;
+	// optimize later...
+	hfs_bnode_read(node, &data, off, 1);
+	return data;
+}
+
+void hfs_bnode_read_key(struct hfs_bnode *node, void *key, u32 off)
+{
+	struct hfs_btree *tree;
+	u32 key_len;
+
+	tree = node->tree;
+	if (node->type == HFS_NODE_LEAF ||
+	    tree->attributes & HFS_TREE_VARIDXKEYS)
+		key_len = hfs_bnode_read_u8(node, off) + 1;
+	else
+		key_len = tree->max_key_len + 1;
+
+	if (key_len > sizeof(hfs_btree_key) || key_len < 1) {
+		memset(key, 0, sizeof(hfs_btree_key));
+		pr_err("hfs: Invalid key length: %u\n", key_len);
+		return;
+	}
+
+	hfs_bnode_read(node, key, off, key_len);
+}
+
+void hfs_bnode_write(struct hfs_bnode *node, void *buf, u32 off, u32 len)
+{
+	struct page *page;
+
+	if (!is_bnode_offset_valid(node, off))
+		return;
+
+	if (len == 0) {
+		pr_err("requested zero length: "
+		       "NODE: id %u, type %#x, height %u, "
+		       "node_size %u, offset %u, len %u\n",
+		       node->this, node->type, node->height,
+		       node->tree->node_size, off, len);
+		return;
+	}
+
+	len = check_and_correct_requested_length(node, off, len);
+
+	off += node->page_offset;
+	page = node->page[0];
+
+	memcpy_to_page(page, off, buf, len);
+	set_page_dirty(page);
+}
+
+void hfs_bnode_write_u16(struct hfs_bnode *node, u32 off, u16 data)
+{
+	__be16 v = cpu_to_be16(data);
+	// optimize later...
+	hfs_bnode_write(node, &v, off, 2);
+}
+
+void hfs_bnode_write_u8(struct hfs_bnode *node, u32 off, u8 data)
+{
+	// optimize later...
+	hfs_bnode_write(node, &data, off, 1);
+}
+
+void hfs_bnode_clear(struct hfs_bnode *node, u32 off, u32 len)
+{
+	struct page *page;
+
+	if (!is_bnode_offset_valid(node, off))
+		return;
+
+	if (len == 0) {
+		pr_err("requested zero length: "
+		       "NODE: id %u, type %#x, height %u, "
+		       "node_size %u, offset %u, len %u\n",
+		       node->this, node->type, node->height,
+		       node->tree->node_size, off, len);
+		return;
+	}
+
+	len = check_and_correct_requested_length(node, off, len);
+
+	off += node->page_offset;
+	page = node->page[0];
+
+	memzero_page(page, off, len);
+	set_page_dirty(page);
+}
+
+void hfs_bnode_copy(struct hfs_bnode *dst_node, u32 dst,
+		    struct hfs_bnode *src_node, u32 src, u32 len)
+{
+	struct page *src_page, *dst_page;
+
+	hfs_dbg("dst %u, src %u, len %u\n", dst, src, len);
+	if (!len)
+		return;
+
+	len = check_and_correct_requested_length(src_node, src, len);
+	len = check_and_correct_requested_length(dst_node, dst, len);
+
+	src += src_node->page_offset;
+	dst += dst_node->page_offset;
+	src_page = src_node->page[0];
+	dst_page = dst_node->page[0];
+
+	memcpy_page(dst_page, dst, src_page, src, len);
+	set_page_dirty(dst_page);
+}
+
+void hfs_bnode_move(struct hfs_bnode *node, u32 dst, u32 src, u32 len)
+{
+	struct page *page;
+	void *ptr;
+
+	hfs_dbg("dst %u, src %u, len %u\n", dst, src, len);
+	if (!len)
+		return;
+
+	len = check_and_correct_requested_length(node, src, len);
+	len = check_and_correct_requested_length(node, dst, len);
+
+	src += node->page_offset;
+	dst += node->page_offset;
+	page = node->page[0];
+	ptr = kmap_local_page(page);
+	memmove(ptr + dst, ptr + src, len);
+	kunmap_local(ptr);
+	set_page_dirty(page);
+}
+
+void hfs_bnode_dump(struct hfs_bnode *node)
+{
+	struct hfs_bnode_desc desc;
+	__be32 cnid;
+	int i, off, key_off;
+
+	hfs_dbg("node %d\n", node->this);
+	hfs_bnode_read(node, &desc, 0, sizeof(desc));
+	hfs_dbg("next %d, prev %d, type %d, height %d, num_recs %d\n",
+		be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
+		desc.type, desc.height, be16_to_cpu(desc.num_recs));
+
+	off = node->tree->node_size - 2;
+	for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
+		key_off = hfs_bnode_read_u16(node, off);
+		hfs_dbg(" key_off %d", key_off);
+		if (i && node->type == HFS_NODE_INDEX) {
+			int tmp;
+
+			if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
+				tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1;
+			else
+				tmp = node->tree->max_key_len + 1;
+			hfs_dbg(" (%d,%d",
+				tmp, hfs_bnode_read_u8(node, key_off));
+			hfs_bnode_read(node, &cnid, key_off + tmp, 4);
+			hfs_dbg(", cnid %d)", be32_to_cpu(cnid));
+		} else if (i && node->type == HFS_NODE_LEAF) {
+			int tmp;
+
+			tmp = hfs_bnode_read_u8(node, key_off);
+			hfs_dbg(" (%d)", tmp);
+		}
+	}
+	hfs_dbg("\n");
+}
+
+void hfs_bnode_unlink(struct hfs_bnode *node)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *tmp;
+	__be32 cnid;
+
+	tree = node->tree;
+	if (node->prev) {
+		tmp = hfs_bnode_find(tree, node->prev);
+		if (IS_ERR(tmp))
+			return;
+		tmp->next = node->next;
+		cnid = cpu_to_be32(tmp->next);
+		hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
+		hfs_bnode_put(tmp);
+	} else if (node->type == HFS_NODE_LEAF)
+		tree->leaf_head = node->next;
+
+	if (node->next) {
+		tmp = hfs_bnode_find(tree, node->next);
+		if (IS_ERR(tmp))
+			return;
+		tmp->prev = node->prev;
+		cnid = cpu_to_be32(tmp->prev);
+		hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
+		hfs_bnode_put(tmp);
+	} else if (node->type == HFS_NODE_LEAF)
+		tree->leaf_tail = node->prev;
+
+	// move down?
+	if (!node->prev && !node->next) {
+		printk(KERN_DEBUG "hfs_btree_del_level\n");
+	}
+	if (!node->parent) {
+		tree->root = 0;
+		tree->depth = 0;
+	}
+	set_bit(HFS_BNODE_DELETED, &node->flags);
+}
+
+static inline int hfs_bnode_hash(u32 num)
+{
+	num = (num >> 16) + num;
+	num += num >> 8;
+	return num & (NODE_HASH_SIZE - 1);
+}
+
+struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
+{
+	struct hfs_bnode *node;
+
+	if (cnid >= tree->node_count) {
+		pr_err("request for non-existent node %d in B*Tree\n", cnid);
+		return NULL;
+	}
+
+	for (node = tree->node_hash[hfs_bnode_hash(cnid)];
+	     node; node = node->next_hash) {
+		if (node->this == cnid) {
+			return node;
+		}
+	}
+	return NULL;
+}
+
+static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
+{
+	struct hfs_bnode *node, *node2;
+	struct address_space *mapping;
+	struct page *page;
+	int block, i, hash;
+	loff_t off;
+
+	if (cnid >= tree->node_count) {
+		pr_err("request for non-existent node %d in B*Tree\n", cnid);
+		return NULL;
+	}
+
+	node = kzalloc_flex(*node, page, tree->pages_per_bnode);
+	if (!node)
+		return NULL;
+	node->tree = tree;
+	node->this = cnid;
+	set_bit(HFS_BNODE_NEW, &node->flags);
+	atomic_set(&node->refcnt, 1);
+	hfs_dbg("cnid %d, node %d, refcnt 1\n",
+		node->tree->cnid, node->this);
+	init_waitqueue_head(&node->lock_wq);
+	spin_lock(&tree->hash_lock);
+	node2 = hfs_bnode_findhash(tree, cnid);
+	if (!node2) {
+		hash = hfs_bnode_hash(cnid);
+		node->next_hash = tree->node_hash[hash];
+		tree->node_hash[hash] = node;
+		tree->node_hash_cnt++;
+	} else {
+		hfs_bnode_get(node2);
+		spin_unlock(&tree->hash_lock);
+		kfree(node);
+		wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
+		return node2;
+	}
+	spin_unlock(&tree->hash_lock);
+
+	mapping = tree->inode->i_mapping;
+	off = (loff_t)cnid * tree->node_size;
+	block = off >> PAGE_SHIFT;
+	node->page_offset = off & ~PAGE_MASK;
+	for (i = 0; i < tree->pages_per_bnode; i++) {
+		page = read_mapping_page(mapping, block++, NULL);
+		if (IS_ERR(page))
+			goto fail;
+		node->page[i] = page;
+	}
+
+	return node;
+fail:
+	set_bit(HFS_BNODE_ERROR, &node->flags);
+	return node;
+}
+
+void hfs_bnode_unhash(struct hfs_bnode *node)
+{
+	struct hfs_bnode **p;
+
+	hfs_dbg("cnid %d, node %d, refcnt %d\n",
+		node->tree->cnid, node->this, atomic_read(&node->refcnt));
+	for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
+	     *p && *p != node; p = &(*p)->next_hash)
+		;
+	BUG_ON(!*p);
+	*p = node->next_hash;
+	node->tree->node_hash_cnt--;
+}
+
+/* Load a particular node out of a tree */
+struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
+{
+	struct hfs_bnode *node;
+	struct hfs_bnode_desc *desc;
+	int i, rec_off, off, next_off;
+	int entry_size, key_size;
+
+	spin_lock(&tree->hash_lock);
+	node = hfs_bnode_findhash(tree, num);
+	if (node) {
+		hfs_bnode_get(node);
+		spin_unlock(&tree->hash_lock);
+		wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
+		if (test_bit(HFS_BNODE_ERROR, &node->flags))
+			goto node_error;
+		return node;
+	}
+	spin_unlock(&tree->hash_lock);
+	node = __hfs_bnode_create(tree, num);
+	if (!node)
+		return ERR_PTR(-ENOMEM);
+	if (test_bit(HFS_BNODE_ERROR, &node->flags))
+		goto node_error;
+	if (!test_bit(HFS_BNODE_NEW, &node->flags))
+		return node;
+
+	desc = (struct hfs_bnode_desc *)(kmap_local_page(node->page[0]) +
+					 node->page_offset);
+	node->prev = be32_to_cpu(desc->prev);
+	node->next = be32_to_cpu(desc->next);
+	node->num_recs = be16_to_cpu(desc->num_recs);
+	node->type = desc->type;
+	node->height = desc->height;
+	kunmap_local(desc);
+
+	switch (node->type) {
+	case HFS_NODE_HEADER:
+	case HFS_NODE_MAP:
+		if (node->height != 0)
+			goto node_error;
+		break;
+	case HFS_NODE_LEAF:
+		if (node->height != 1)
+			goto node_error;
+		break;
+	case HFS_NODE_INDEX:
+		if (node->height <= 1 || node->height > tree->depth)
+			goto node_error;
+		break;
+	default:
+		goto node_error;
+	}
+
+	rec_off = tree->node_size - 2;
+	off = hfs_bnode_read_u16(node, rec_off);
+	if (off != sizeof(struct hfs_bnode_desc))
+		goto node_error;
+	for (i = 1; i <= node->num_recs; off = next_off, i++) {
+		rec_off -= 2;
+		next_off = hfs_bnode_read_u16(node, rec_off);
+		if (next_off <= off ||
+		    next_off > tree->node_size ||
+		    next_off & 1)
+			goto node_error;
+		entry_size = next_off - off;
+		if (node->type != HFS_NODE_INDEX &&
+		    node->type != HFS_NODE_LEAF)
+			continue;
+		key_size = hfs_bnode_read_u8(node, off) + 1;
+		if (key_size >= entry_size /*|| key_size & 1*/)
+			goto node_error;
+	}
+	clear_bit(HFS_BNODE_NEW, &node->flags);
+	wake_up(&node->lock_wq);
+	return node;
+
+node_error:
+	set_bit(HFS_BNODE_ERROR, &node->flags);
+	clear_bit(HFS_BNODE_NEW, &node->flags);
+	wake_up(&node->lock_wq);
+	hfs_bnode_put(node);
+	return ERR_PTR(-EIO);
+}
+
+void hfs_bnode_free(struct hfs_bnode *node)
+{
+	int i;
+
+	for (i = 0; i < node->tree->pages_per_bnode; i++)
+		if (node->page[i])
+			put_page(node->page[i]);
+	kfree(node);
+}
+
+struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
+{
+	struct hfs_bnode *node;
+	struct page **pagep;
+	int i;
+
+	spin_lock(&tree->hash_lock);
+	node = hfs_bnode_findhash(tree, num);
+	spin_unlock(&tree->hash_lock);
+	if (node) {
+		pr_crit("new node %u already hashed?\n", num);
+		WARN_ON(1);
+		return node;
+	}
+	node = __hfs_bnode_create(tree, num);
+	if (!node)
+		return ERR_PTR(-ENOMEM);
+	if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
+		hfs_bnode_put(node);
+		return ERR_PTR(-EIO);
+	}
+
+	pagep = node->page;
+	memzero_page(*pagep, node->page_offset,
+		     min((int)PAGE_SIZE, (int)tree->node_size));
+	set_page_dirty(*pagep);
+	for (i = 1; i < tree->pages_per_bnode; i++) {
+		memzero_page(*++pagep, 0, PAGE_SIZE);
+		set_page_dirty(*pagep);
+	}
+	clear_bit(HFS_BNODE_NEW, &node->flags);
+	wake_up(&node->lock_wq);
+
+	return node;
+}
+
+void hfs_bnode_get(struct hfs_bnode *node)
+{
+	if (node) {
+		atomic_inc(&node->refcnt);
+		hfs_dbg("cnid %d, node %d, refcnt %d\n",
+			node->tree->cnid, node->this,
+			atomic_read(&node->refcnt));
+	}
+}
+
+/* Dispose of resources used by a node */
+void hfs_bnode_put(struct hfs_bnode *node)
+{
+	if (node) {
+		struct hfs_btree *tree = node->tree;
+		int i;
+
+		hfs_dbg("cnid %d, node %d, refcnt %d\n",
+			node->tree->cnid, node->this,
+			atomic_read(&node->refcnt));
+		BUG_ON(!atomic_read(&node->refcnt));
+		if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
+			return;
+		for (i = 0; i < tree->pages_per_bnode; i++) {
+			if (!node->page[i])
+				continue;
+			mark_page_accessed(node->page[i]);
+		}
+
+		if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
+			hfs_bnode_unhash(node);
+			spin_unlock(&tree->hash_lock);
+			hfs_bnode_clear(node, 0, tree->node_size);
+			hfs_bmap_free(node);
+			hfs_bnode_free(node);
+			return;
+		}
+		spin_unlock(&tree->hash_lock);
+	}
+}
diff --git a/fs/hfs/brec.c b/fs/hfs/brec.c
new file mode 100644
index 000000000..5a2f740dd
--- /dev/null
+++ b/fs/hfs/brec.c
@@ -0,0 +1,548 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hfs/brec.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handle individual btree records
+ */
+
+#include "btree.h"
+
+static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd);
+static int hfs_brec_update_parent(struct hfs_find_data *fd);
+static int hfs_btree_inc_height(struct hfs_btree *tree);
+
+/* Get the length and offset of the given record in the given node */
+u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off)
+{
+	__be16 retval[2];
+	u16 dataoff;
+
+	dataoff = node->tree->node_size - (rec + 2) * 2;
+	hfs_bnode_read(node, retval, dataoff, 4);
+	*off = be16_to_cpu(retval[1]);
+	return be16_to_cpu(retval[0]) - *off;
+}
+
+/* Get the length of the key from a keyed record */
+u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
+{
+	u16 retval, recoff;
+
+	if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
+		return 0;
+
+	if ((node->type == HFS_NODE_INDEX) &&
+	   !(node->tree->attributes & HFS_TREE_VARIDXKEYS)) {
+		if (node->tree->attributes & HFS_TREE_BIGKEYS)
+			retval = node->tree->max_key_len + 2;
+		else
+			retval = node->tree->max_key_len + 1;
+	} else {
+		recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2);
+		if (!recoff)
+			return 0;
+		if (node->tree->attributes & HFS_TREE_BIGKEYS) {
+			retval = hfs_bnode_read_u16(node, recoff) + 2;
+			if (retval > node->tree->max_key_len + 2) {
+				pr_err("keylen %d too large\n", retval);
+				retval = 0;
+			}
+		} else {
+			retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
+			if (retval > node->tree->max_key_len + 1) {
+				pr_err("keylen %d too large\n", retval);
+				retval = 0;
+			}
+		}
+	}
+	return retval;
+}
+
+int hfs_brec_insert(struct hfs_find_data *fd, void *entry, u32 entry_len)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *node, *new_node;
+	int size, key_len, rec;
+	int data_off, end_off;
+	int idx_rec_off, data_rec_off, end_rec_off;
+	__be32 cnid;
+
+	tree = fd->tree;
+	if (!fd->bnode) {
+		if (!tree->root)
+			hfs_btree_inc_height(tree);
+		node = hfs_bnode_find(tree, tree->leaf_head);
+		if (IS_ERR(node))
+			return PTR_ERR(node);
+		fd->bnode = node;
+		fd->record = -1;
+	}
+	new_node = NULL;
+	key_len = (fd->search_key->key_len | 1) + 1;
+again:
+	/* new record idx and complete record size */
+	rec = fd->record + 1;
+	size = key_len + entry_len;
+
+	node = fd->bnode;
+	hfs_bnode_dump(node);
+	/* get last offset */
+	end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
+	end_off = hfs_bnode_read_u16(node, end_rec_off);
+	end_rec_off -= 2;
+	hfs_dbg("rec %d, size %d, end_off %d, end_rec_off %d\n",
+		rec, size, end_off, end_rec_off);
+	if (size > end_rec_off - end_off) {
+		if (new_node)
+			panic("not enough room!\n");
+		new_node = hfs_bnode_split(fd);
+		if (IS_ERR(new_node))
+			return PTR_ERR(new_node);
+		goto again;
+	}
+	if (node->type == HFS_NODE_LEAF) {
+		tree->leaf_count++;
+		mark_inode_dirty(tree->inode);
+	}
+	node->num_recs++;
+	/* write new last offset */
+	hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
+	hfs_bnode_write_u16(node, end_rec_off, end_off + size);
+	data_off = end_off;
+	data_rec_off = end_rec_off + 2;
+	idx_rec_off = tree->node_size - (rec + 1) * 2;
+	if (idx_rec_off == data_rec_off)
+		goto skip;
+	/* move all following entries */
+	do {
+		data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
+		hfs_bnode_write_u16(node, data_rec_off, data_off + size);
+		data_rec_off += 2;
+	} while (data_rec_off < idx_rec_off);
+
+	/* move data away */
+	hfs_bnode_move(node, data_off + size, data_off,
+		       end_off - data_off);
+
+skip:
+	hfs_bnode_write(node, fd->search_key, data_off, key_len);
+	hfs_bnode_write(node, entry, data_off + key_len, entry_len);
+	hfs_bnode_dump(node);
+
+	/*
+	 * update parent key if we inserted a key
+	 * at the start of the node and it is not the new node
+	 */
+	if (!rec && new_node != node) {
+		hfs_bnode_read_key(node, fd->search_key, data_off + size);
+		hfs_brec_update_parent(fd);
+	}
+
+	if (new_node) {
+		hfs_bnode_put(fd->bnode);
+		if (!new_node->parent) {
+			hfs_btree_inc_height(tree);
+			new_node->parent = tree->root;
+		}
+		fd->bnode = hfs_bnode_find(tree, new_node->parent);
+
+		/* create index data entry */
+		cnid = cpu_to_be32(new_node->this);
+		entry = &cnid;
+		entry_len = sizeof(cnid);
+
+		/* get index key */
+		hfs_bnode_read_key(new_node, fd->search_key, 14);
+		__hfs_brec_find(fd->bnode, fd);
+
+		hfs_bnode_put(new_node);
+		new_node = NULL;
+
+		if (tree->attributes & HFS_TREE_VARIDXKEYS)
+			key_len = fd->search_key->key_len + 1;
+		else {
+			fd->search_key->key_len = tree->max_key_len;
+			key_len = tree->max_key_len + 1;
+		}
+		goto again;
+	}
+
+	return 0;
+}
+
+int hfs_brec_remove(struct hfs_find_data *fd)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *node, *parent;
+	int end_off, rec_off, data_off, size;
+	int src, dst, len;
+
+	tree = fd->tree;
+	node = fd->bnode;
+again:
+	rec_off = tree->node_size - (fd->record + 2) * 2;
+	end_off = tree->node_size - (node->num_recs + 1) * 2;
+
+	if (node->type == HFS_NODE_LEAF) {
+		tree->leaf_count--;
+		mark_inode_dirty(tree->inode);
+	}
+	hfs_bnode_dump(node);
+	hfs_dbg("rec %d, len %d\n",
+		fd->record, fd->keylength + fd->entrylength);
+	if (!--node->num_recs) {
+		hfs_bnode_unlink(node);
+		if (!node->parent)
+			return 0;
+		parent = hfs_bnode_find(tree, node->parent);
+		if (IS_ERR(parent))
+			return PTR_ERR(parent);
+		hfs_bnode_put(node);
+		node = fd->bnode = parent;
+
+		__hfs_brec_find(node, fd);
+		goto again;
+	}
+	hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
+
+	size = fd->keylength + fd->entrylength;
+
+	if (rec_off == end_off) {
+		src = fd->keyoffset;
+		hfs_bnode_clear(node, src, size);
+		goto skip;
+	}
+
+	do {
+		data_off = hfs_bnode_read_u16(node, rec_off);
+		hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
+		rec_off -= 2;
+	} while (rec_off >= end_off);
+
+	/* fill hole */
+	dst = fd->keyoffset;
+	src = fd->keyoffset + size;
+	len = data_off - src;
+
+	hfs_bnode_move(node, dst, src, len);
+
+	src = dst + len;
+	len = data_off - src;
+
+	hfs_bnode_clear(node, src, len);
+
+skip:
+	/*
+	 * Remove the obsolete offset to free space.
+	 */
+	hfs_bnode_write_u16(node, end_off, 0);
+
+	hfs_bnode_dump(node);
+	if (!fd->record)
+		hfs_brec_update_parent(fd);
+	return 0;
+}
+
+static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *node, *new_node, *next_node;
+	struct hfs_bnode_desc node_desc;
+	int num_recs, new_rec_off, new_off, old_rec_off;
+	int data_start, data_end, size;
+
+	tree = fd->tree;
+	node = fd->bnode;
+	new_node = hfs_bmap_alloc(tree);
+	if (IS_ERR(new_node))
+		return new_node;
+	hfs_bnode_get(node);
+	hfs_dbg("this %d, new %d, next %d\n",
+		node->this, new_node->this, node->next);
+	new_node->next = node->next;
+	new_node->prev = node->this;
+	new_node->parent = node->parent;
+	new_node->type = node->type;
+	new_node->height = node->height;
+
+	if (node->next)
+		next_node = hfs_bnode_find(tree, node->next);
+	else
+		next_node = NULL;
+
+	if (IS_ERR(next_node)) {
+		hfs_bnode_put(node);
+		hfs_bnode_put(new_node);
+		return next_node;
+	}
+
+	size = tree->node_size / 2 - node->num_recs * 2 - 14;
+	old_rec_off = tree->node_size - 4;
+	num_recs = 1;
+	for (;;) {
+		data_start = hfs_bnode_read_u16(node, old_rec_off);
+		if (data_start > size)
+			break;
+		old_rec_off -= 2;
+		if (++num_recs < node->num_recs)
+			continue;
+		/* panic? */
+		hfs_bnode_put(node);
+		hfs_bnode_put(new_node);
+		if (next_node)
+			hfs_bnode_put(next_node);
+		return ERR_PTR(-ENOSPC);
+	}
+
+	if (fd->record + 1 < num_recs) {
+		/* new record is in the lower half,
+		 * so leave some more space there
+		 */
+		old_rec_off += 2;
+		num_recs--;
+		data_start = hfs_bnode_read_u16(node, old_rec_off);
+	} else {
+		hfs_bnode_put(node);
+		hfs_bnode_get(new_node);
+		fd->bnode = new_node;
+		fd->record -= num_recs;
+		fd->keyoffset -= data_start - 14;
+		fd->entryoffset -= data_start - 14;
+	}
+	new_node->num_recs = node->num_recs - num_recs;
+	node->num_recs = num_recs;
+
+	new_rec_off = tree->node_size - 2;
+	new_off = 14;
+	size = data_start - new_off;
+	num_recs = new_node->num_recs;
+	data_end = data_start;
+	while (num_recs) {
+		hfs_bnode_write_u16(new_node, new_rec_off, new_off);
+		old_rec_off -= 2;
+		new_rec_off -= 2;
+		data_end = hfs_bnode_read_u16(node, old_rec_off);
+		new_off = data_end - size;
+		num_recs--;
+	}
+	hfs_bnode_write_u16(new_node, new_rec_off, new_off);
+	hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
+
+	/* update new bnode header */
+	node_desc.next = cpu_to_be32(new_node->next);
+	node_desc.prev = cpu_to_be32(new_node->prev);
+	node_desc.type = new_node->type;
+	node_desc.height = new_node->height;
+	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
+	node_desc.reserved = 0;
+	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
+
+	/* update previous bnode header */
+	node->next = new_node->this;
+	hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
+	node_desc.next = cpu_to_be32(node->next);
+	node_desc.num_recs = cpu_to_be16(node->num_recs);
+	hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
+
+	/* update next bnode header */
+	if (next_node) {
+		next_node->prev = new_node->this;
+		hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
+		node_desc.prev = cpu_to_be32(next_node->prev);
+		hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
+		hfs_bnode_put(next_node);
+	} else if (node->this == tree->leaf_tail) {
+		/* if there is no next node, this might be the new tail */
+		tree->leaf_tail = new_node->this;
+		mark_inode_dirty(tree->inode);
+	}
+
+	hfs_bnode_dump(node);
+	hfs_bnode_dump(new_node);
+	hfs_bnode_put(node);
+
+	return new_node;
+}
+
+static int hfs_brec_update_parent(struct hfs_find_data *fd)
+{
+	struct hfs_btree *tree;
+	struct hfs_bnode *node, *new_node, *parent;
+	int newkeylen, diff;
+	int rec, rec_off, end_rec_off;
+	int start_off, end_off;
+
+	tree = fd->tree;
+	node = fd->bnode;
+	new_node = NULL;
+	if (!node->parent)
+		return 0;
+
+again:
+	parent = hfs_bnode_find(tree, node->parent);
+	if (IS_ERR(parent))
+		return PTR_ERR(parent);
+	__hfs_brec_find(parent, fd);
+	if (fd->record < 0)
+		return -ENOENT;
+	hfs_bnode_dump(parent);
+	rec = fd->record;
+
+	/* size difference between old and new key */
+	if (tree->attributes & HFS_TREE_VARIDXKEYS)
+		newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1;
+	else
+		fd->keylength = newkeylen = tree->max_key_len + 1;
+	hfs_dbg("rec %d, keylength %d, newkeylen %d\n",
+		rec, fd->keylength, newkeylen);
+
+	rec_off = tree->node_size - (rec + 2) * 2;
+	end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
+	diff = newkeylen - fd->keylength;
+	if (!diff)
+		goto skip;
+	if (diff > 0) {
+		end_off = hfs_bnode_read_u16(parent, end_rec_off);
+		if (end_rec_off - end_off < diff) {
+
+			printk(KERN_DEBUG "splitting index node...\n");
+			fd->bnode = parent;
+			new_node = hfs_bnode_split(fd);
+			if (IS_ERR(new_node))
+				return PTR_ERR(new_node);
+			parent = fd->bnode;
+			rec = fd->record;
+			rec_off = tree->node_size - (rec + 2) * 2;
+			end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
+		}
+	}
+
+	end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
+	hfs_bnode_write_u16(parent, rec_off, start_off + diff);
+	start_off -= 4;	/* move previous cnid too */
+
+	while (rec_off > end_rec_off) {
+		rec_off -= 2;
+		end_off = hfs_bnode_read_u16(parent, rec_off);
+		hfs_bnode_write_u16(parent, rec_off, end_off + diff);
+	}
+	hfs_bnode_move(parent, start_off + diff, start_off,
+		       end_off - start_off);
+skip:
+	hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
+	if (!(tree->attributes & HFS_TREE_VARIDXKEYS))
+		hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1);
+	hfs_bnode_dump(parent);
+
+	hfs_bnode_put(node);
+	node = parent;
+
+	if (new_node) {
+		__be32 cnid;
+
+		if (!new_node->parent) {
+			hfs_btree_inc_height(tree);
+			new_node->parent = tree->root;
+		}
+		fd->bnode = hfs_bnode_find(tree, new_node->parent);
+		/* create index key and entry */
+		hfs_bnode_read_key(new_node, fd->search_key, 14);
+		cnid = cpu_to_be32(new_node->this);
+
+		__hfs_brec_find(fd->bnode, fd);
+		hfs_brec_insert(fd, &cnid, sizeof(cnid));
+		hfs_bnode_put(fd->bnode);
+		hfs_bnode_put(new_node);
+
+		if (!rec) {
+			if (new_node == node)
+				goto out;
+			/* restore search_key */
+			hfs_bnode_read_key(node, fd->search_key, 14);
+		}
+		new_node = NULL;
+	}
+
+	if (!rec && node->parent)
+		goto again;
+out:
+	fd->bnode = node;
+	return 0;
+}
+
+static int hfs_btree_inc_height(struct hfs_btree *tree)
+{
+	struct hfs_bnode *node, *new_node;
+	struct hfs_bnode_desc node_desc;
+	int key_size, rec;
+	__be32 cnid;
+
+	node = NULL;
+	if (tree->root) {
+		node = hfs_bnode_find(tree, tree->root);
+		if (IS_ERR(node))
+			return PTR_ERR(node);
+	}
+	new_node = hfs_bmap_alloc(tree);
+	if (IS_ERR(new_node)) {
+		hfs_bnode_put(node);
+		return PTR_ERR(new_node);
+	}
+
+	tree->root = new_node->this;
+	if (!tree->depth) {
+		tree->leaf_head = tree->leaf_tail = new_node->this;
+		new_node->type = HFS_NODE_LEAF;
+		new_node->num_recs = 0;
+	} else {
+		new_node->type = HFS_NODE_INDEX;
+		new_node->num_recs = 1;
+	}
+	new_node->parent = 0;
+	new_node->next = 0;
+	new_node->prev = 0;
+	new_node->height = ++tree->depth;
+
+	node_desc.next = cpu_to_be32(new_node->next);
+	node_desc.prev = cpu_to_be32(new_node->prev);
+	node_desc.type = new_node->type;
+	node_desc.height = new_node->height;
+	node_desc.num_recs = cpu_to_be16(new_node->num_recs);
+	node_desc.reserved = 0;
+	hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
+
+	rec = tree->node_size - 2;
+	hfs_bnode_write_u16(new_node, rec, 14);
+
+	if (node) {
+		/* insert old root idx into new root */
+		node->parent = tree->root;
+		if (node->type == HFS_NODE_LEAF ||
+		    tree->attributes & HFS_TREE_VARIDXKEYS)
+			key_size = hfs_bnode_read_u8(node, 14) + 1;
+		else
+			key_size = tree->max_key_len + 1;
+		hfs_bnode_copy(new_node, 14, node, 14, key_size);
+
+		if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
+			key_size = tree->max_key_len + 1;
+			hfs_bnode_write_u8(new_node, 14, tree->max_key_len);
+		}
+		key_size = (key_size + 1) & -2;
+		cnid = cpu_to_be32(node->this);
+		hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
+
+		rec -= 2;
+		hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
+
+		hfs_bnode_put(node);
+	}
+	hfs_bnode_put(new_node);
+	mark_inode_dirty(tree->inode);
+
+	return 0;
+}
diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c
new file mode 100644
index 000000000..41b4e8fc9
--- /dev/null
+++ b/fs/hfs/btree.c
@@ -0,0 +1,544 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hfs/btree.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handle opening/closing btree
+ */
+
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/log2.h>
+
+#include "btree.h"
+
+/* Context for iterating b-tree map pages
+ * @page_idx: The index of the page within the b-node's page array
+ * @off: The byte offset within the mapped page
+ * @len: The remaining length of the map record
+ */
+struct hfs_bmap_ctx {
+	unsigned int page_idx;
+	unsigned int off;
+	u16 len;
+};
+
+/*
+ * Finds the specific page containing the requested byte offset within the map
+ * record. Automatically handles the difference between header and map nodes.
+ * Returns the struct page pointer, or an ERR_PTR on failure.
+ * Note: The caller is responsible for mapping/unmapping the returned page.
+ */
+static struct page *hfs_bmap_get_map_page(struct hfs_bnode *node,
+					  struct hfs_bmap_ctx *ctx,
+					  u32 byte_offset)
+{
+	u16 rec_idx, off16;
+	unsigned int page_off;
+
+	if (node->this == HFS_TREE_HEAD) {
+		if (node->type != HFS_NODE_HEADER) {
+			pr_err("hfs: invalid btree header node\n");
+			return ERR_PTR(-EIO);
+		}
+		rec_idx = HFS_BTREE_HDR_MAP_REC_INDEX;
+	} else {
+		if (node->type != HFS_NODE_MAP) {
+			pr_err("hfs: invalid btree map node\n");
+			return ERR_PTR(-EIO);
+		}
+		rec_idx = HFS_BTREE_MAP_NODE_REC_INDEX;
+	}
+
+	ctx->len = hfs_brec_lenoff(node, rec_idx, &off16);
+	if (!ctx->len)
+		return ERR_PTR(-ENOENT);
+
+	if (!is_bnode_offset_valid(node, off16))
+		return ERR_PTR(-EIO);
+
+	ctx->len = check_and_correct_requested_length(node, off16, ctx->len);
+
+	if (byte_offset >= ctx->len)
+		return ERR_PTR(-EINVAL);
+
+	page_off = (u32)off16 + node->page_offset + byte_offset;
+	ctx->page_idx = page_off >> PAGE_SHIFT;
+	ctx->off = page_off & ~PAGE_MASK;
+
+	return node->page[ctx->page_idx];
+}
+
+/**
+ * hfs_bmap_test_bit - test a bit in the b-tree map
+ * @node: the b-tree node containing the map record
+ * @node_bit_idx: the relative bit index within the node's map record
+ *
+ * Returns true if set, false if clear or on failure.
+ */
+static bool hfs_bmap_test_bit(struct hfs_bnode *node, u32 node_bit_idx)
+{
+	struct hfs_bmap_ctx ctx;
+	struct page *page;
+	u8 *bmap, byte, mask;
+
+	page = hfs_bmap_get_map_page(node, &ctx, node_bit_idx / BITS_PER_BYTE);
+	if (IS_ERR(page))
+		return false;
+
+	bmap = kmap_local_page(page);
+	byte = bmap[ctx.off];
+	kunmap_local(bmap);
+
+	mask = 1 << (7 - (node_bit_idx % BITS_PER_BYTE));
+	return (byte & mask) != 0;
+}
+
+/**
+ * hfs_bmap_clear_bit - clear a bit in the b-tree map
+ * @node: the b-tree node containing the map record
+ * @node_bit_idx: the relative bit index within the node's map record
+ *
+ * Returns 0 on success, -EINVAL if already clear, or negative error code.
+ */
+static int hfs_bmap_clear_bit(struct hfs_bnode *node, u32 node_bit_idx)
+{
+	struct hfs_bmap_ctx ctx;
+	struct page *page;
+	u8 *bmap, mask;
+
+	page = hfs_bmap_get_map_page(node, &ctx, node_bit_idx / BITS_PER_BYTE);
+	if (IS_ERR(page))
+		return PTR_ERR(page);
+
+	bmap = kmap_local_page(page);
+
+	mask = 1 << (7 - (node_bit_idx % BITS_PER_BYTE));
+
+	if (!(bmap[ctx.off] & mask)) {
+		kunmap_local(bmap);
+		return -EINVAL;
+	}
+
+	bmap[ctx.off] &= ~mask;
+	set_page_dirty(page);
+	kunmap_local(bmap);
+
+	return 0;
+}
+
+/* Get a reference to a B*Tree and do some initial checks */
+struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp keycmp)
+{
+	struct hfs_btree *tree;
+	struct hfs_btree_header_rec *head;
+	struct address_space *mapping;
+	struct folio *folio;
+	struct buffer_head *bh;
+	struct hfs_bnode *node;
+	unsigned int size;
+	u16 dblock;
+	sector_t start_block;
+	loff_t offset;
+
+	tree = kzalloc_obj(*tree);
+	if (!tree)
+		return NULL;
+
+	mutex_init(&tree->tree_lock);
+	spin_lock_init(&tree->hash_lock);
+	/* Set the correct compare function */
+	tree->sb = sb;
+	tree->cnid = id;
+	tree->keycmp = keycmp;
+
+	tree->inode = iget_locked(sb, id);
+	if (!tree->inode)
+		goto free_tree;
+	BUG_ON(!(inode_state_read_once(tree->inode) & I_NEW));
+	{
+	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
+	HFS_I(tree->inode)->flags = 0;
+	mutex_init(&HFS_I(tree->inode)->extents_lock);
+	switch (id) {
+	case HFS_EXT_CNID:
+		hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize,
+				    mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz));
+		if (HFS_I(tree->inode)->alloc_blocks >
+					HFS_I(tree->inode)->first_blocks) {
+			pr_err("invalid btree extent records\n");
+			unlock_new_inode(tree->inode);
+			goto free_inode;
+		}
+
+		tree->inode->i_mapping->a_ops = &hfs_btree_aops;
+		break;
+	case HFS_CAT_CNID:
+		hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize,
+				    mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz));
+
+		if (!HFS_I(tree->inode)->first_blocks) {
+			pr_err("invalid btree extent records (0 size)\n");
+			unlock_new_inode(tree->inode);
+			goto free_inode;
+		}
+
+		tree->inode->i_mapping->a_ops = &hfs_btree_aops;
+		break;
+	default:
+		BUG();
+	}
+	}
+	unlock_new_inode(tree->inode);
+
+	mapping = tree->inode->i_mapping;
+	folio = filemap_grab_folio(mapping, 0);
+	if (IS_ERR(folio))
+		goto free_inode;
+
+	folio_zero_range(folio, 0, folio_size(folio));
+
+	dblock = hfs_ext_find_block(HFS_I(tree->inode)->first_extents, 0);
+	start_block = HFS_SB(sb)->fs_start + (dblock * HFS_SB(sb)->fs_div);
+
+	size = folio_size(folio);
+	offset = 0;
+	while (size > 0) {
+		size_t len;
+
+		bh = sb_bread(sb, start_block);
+		if (!bh) {
+			pr_err("unable to read tree header\n");
+			goto put_folio;
+		}
+
+		len = min_t(size_t, folio_size(folio), sb->s_blocksize);
+		memcpy_to_folio(folio, offset, bh->b_data, sb->s_blocksize);
+
+		brelse(bh);
+
+		start_block++;
+		offset += len;
+		size -= len;
+	}
+
+	folio_mark_uptodate(folio);
+
+	/* Load the header */
+	head = (struct hfs_btree_header_rec *)(kmap_local_folio(folio, 0) +
+					       sizeof(struct hfs_bnode_desc));
+	tree->root = be32_to_cpu(head->root);
+	tree->leaf_count = be32_to_cpu(head->leaf_count);
+	tree->leaf_head = be32_to_cpu(head->leaf_head);
+	tree->leaf_tail = be32_to_cpu(head->leaf_tail);
+	tree->node_count = be32_to_cpu(head->node_count);
+	tree->free_nodes = be32_to_cpu(head->free_nodes);
+	tree->attributes = be32_to_cpu(head->attributes);
+	tree->node_size = be16_to_cpu(head->node_size);
+	tree->max_key_len = be16_to_cpu(head->max_key_len);
+	tree->depth = be16_to_cpu(head->depth);
+
+	size = tree->node_size;
+	if (!is_power_of_2(size))
+		goto fail_folio;
+	if (!tree->node_count)
+		goto fail_folio;
+	switch (id) {
+	case HFS_EXT_CNID:
+		if (tree->max_key_len != HFS_MAX_EXT_KEYLEN) {
+			pr_err("invalid extent max_key_len %d\n",
+			       tree->max_key_len);
+			goto fail_folio;
+		}
+		break;
+	case HFS_CAT_CNID:
+		if (tree->max_key_len != HFS_MAX_CAT_KEYLEN) {
+			pr_err("invalid catalog max_key_len %d\n",
+			       tree->max_key_len);
+			goto fail_folio;
+		}
+		break;
+	default:
+		BUG();
+	}
+
+	tree->node_size_shift = ffs(size) - 1;
+	tree->pages_per_bnode = (tree->node_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+	kunmap_local(head);
+	folio_unlock(folio);
+	folio_put(folio);
+
+	node = hfs_bnode_find(tree, HFS_TREE_HEAD);
+	if (IS_ERR(node))
+		goto free_inode;
+
+	if (!hfs_bmap_test_bit(node, HFS_TREE_HEAD)) {
+		pr_warn("(%s): %s (cnid 0x%x) bitmap corrupted, forcing rdonly\n",
+			sb->s_id, id == HFS_EXT_CNID ? "extents" : "catalog", id);
+		pr_warn("Run fsck.hfs to repair.\n");
+		sb->s_flags |= SB_RDONLY;
+	}
+
+	hfs_bnode_put(node);
+
+	return tree;
+
+fail_folio:
+	kunmap_local(head);
+put_folio:
+	folio_unlock(folio);
+	folio_put(folio);
+free_inode:
+	tree->inode->i_mapping->a_ops = &hfs_aops;
+	iput(tree->inode);
+free_tree:
+	kfree(tree);
+	return NULL;
+}
+
+/* Release resources used by a btree */
+void hfs_btree_close(struct hfs_btree *tree)
+{
+	struct hfs_bnode *node;
+	int i;
+
+	if (!tree)
+		return;
+
+	for (i = 0; i < NODE_HASH_SIZE; i++) {
+		while ((node = tree->node_hash[i])) {
+			tree->node_hash[i] = node->next_hash;
+			if (atomic_read(&node->refcnt))
+				pr_err("node %d:%d still has %d user(s)!\n",
+				       node->tree->cnid, node->this,
+				       atomic_read(&node->refcnt));
+			hfs_bnode_free(node);
+			tree->node_hash_cnt--;
+		}
+	}
+	iput(tree->inode);
+	kfree(tree);
+}
+
+void hfs_btree_write(struct hfs_btree *tree)
+{
+	struct hfs_btree_header_rec *head;
+	struct hfs_bnode *node;
+	struct page *page;
+
+	node = hfs_bnode_find(tree, 0);
+	if (IS_ERR(node))
+		/* panic? */
+		return;
+	/* Load the header */
+	page = node->page[0];
+	head = (struct hfs_btree_header_rec *)(kmap_local_page(page) +
+					       sizeof(struct hfs_bnode_desc));
+
+	head->root = cpu_to_be32(tree->root);
+	head->leaf_count = cpu_to_be32(tree->leaf_count);
+	head->leaf_head = cpu_to_be32(tree->leaf_head);
+	head->leaf_tail = cpu_to_be32(tree->leaf_tail);
+	head->node_count = cpu_to_be32(tree->node_count);
+	head->free_nodes = cpu_to_be32(tree->free_nodes);
+	head->attributes = cpu_to_be32(tree->attributes);
+	head->depth = cpu_to_be16(tree->depth);
+
+	kunmap_local(head);
+	set_page_dirty(page);
+	hfs_bnode_put(node);
+}
+
+static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx)
+{
+	struct hfs_btree *tree = prev->tree;
+	struct hfs_bnode *node;
+	struct hfs_bnode_desc desc;
+	__be32 cnid;
+
+	node = hfs_bnode_create(tree, idx);
+	if (IS_ERR(node))
+		return node;
+
+	if (!tree->free_nodes)
+		panic("FIXME!!!");
+	tree->free_nodes--;
+	prev->next = idx;
+	cnid = cpu_to_be32(idx);
+	hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
+
+	node->type = HFS_NODE_MAP;
+	node->num_recs = 1;
+	hfs_bnode_clear(node, 0, tree->node_size);
+	desc.next = 0;
+	desc.prev = 0;
+	desc.type = HFS_NODE_MAP;
+	desc.height = 0;
+	desc.num_recs = cpu_to_be16(1);
+	desc.reserved = 0;
+	hfs_bnode_write(node, &desc, 0, sizeof(desc));
+	hfs_bnode_write_u16(node, 14, 0x8000);
+	hfs_bnode_write_u16(node, tree->node_size - 2, 14);
+	hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6);
+
+	return node;
+}
+
+/* Make sure @tree has enough space for the @rsvd_nodes */
+int hfs_bmap_reserve(struct hfs_btree *tree, u32 rsvd_nodes)
+{
+	struct inode *inode = tree->inode;
+	u32 count;
+	int res;
+
+	while (tree->free_nodes < rsvd_nodes) {
+		res = hfs_extend_file(inode);
+		if (res)
+			return res;
+		HFS_I(inode)->phys_size = inode->i_size =
+				(loff_t)HFS_I(inode)->alloc_blocks *
+				HFS_SB(tree->sb)->alloc_blksz;
+		HFS_I(inode)->fs_blocks = inode->i_size >>
+					  tree->sb->s_blocksize_bits;
+		inode_set_bytes(inode, inode->i_size);
+		count = inode->i_size >> tree->node_size_shift;
+		tree->free_nodes += count - tree->node_count;
+		tree->node_count = count;
+	}
+	return 0;
+}
+
+struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree)
+{
+	struct hfs_bnode *node, *next_node;
+	struct hfs_bmap_ctx ctx;
+	struct page *page;
+	u32 nidx, idx;
+	u8 *data, byte, m;
+	int i, res;
+
+	res = hfs_bmap_reserve(tree, 1);
+	if (res)
+		return ERR_PTR(res);
+
+	nidx = 0;
+	node = hfs_bnode_find(tree, nidx);
+	if (IS_ERR(node))
+		return node;
+
+	page = hfs_bmap_get_map_page(node, &ctx, 0);
+	if (IS_ERR(page)) {
+		res = PTR_ERR(page);
+		hfs_bnode_put(node);
+		return ERR_PTR(res);
+	}
+
+	data = kmap_local_page(page);
+	idx = 0;
+
+	for (;;) {
+		while (ctx.len) {
+			byte = data[ctx.off];
+			if (byte != 0xff) {
+				for (m = 0x80, i = 0; i < 8; m >>= 1, i++) {
+					if (!(byte & m)) {
+						idx += i;
+						data[ctx.off] |= m;
+						set_page_dirty(page);
+						kunmap_local(data);
+						tree->free_nodes--;
+						mark_inode_dirty(tree->inode);
+						hfs_bnode_put(node);
+						return hfs_bnode_create(tree, idx);
+					}
+				}
+			}
+			if (++ctx.off >= PAGE_SIZE) {
+				kunmap_local(data);
+				page = node->page[++ctx.page_idx];
+				data = kmap_local_page(page);
+				ctx.off = 0;
+			}
+			idx += 8;
+			ctx.len--;
+		}
+		kunmap_local(data);
+		nidx = node->next;
+		if (!nidx) {
+			printk(KERN_DEBUG "create new bmap node...\n");
+			next_node = hfs_bmap_new_bmap(node, idx);
+		} else
+			next_node = hfs_bnode_find(tree, nidx);
+		hfs_bnode_put(node);
+		if (IS_ERR(next_node))
+			return next_node;
+		node = next_node;
+
+		page = hfs_bmap_get_map_page(node, &ctx, 0);
+		if (IS_ERR(page)) {
+			res = PTR_ERR(page);
+			hfs_bnode_put(node);
+			return ERR_PTR(res);
+		}
+		data = kmap_local_page(page);
+	}
+}
+
+void hfs_bmap_free(struct hfs_bnode *node)
+{
+	struct hfs_btree *tree;
+	u16 off, len;
+	u32 nidx;
+	int res;
+
+	hfs_dbg("node %u\n", node->this);
+	tree = node->tree;
+	nidx = node->this;
+	node = hfs_bnode_find(tree, 0);
+	if (IS_ERR(node))
+		return;
+	len = hfs_brec_lenoff(node, 2, &off);
+	while (nidx >= len * 8) {
+		u32 i;
+
+		nidx -= len * 8;
+		i = node->next;
+		if (!i) {
+			/* panic */;
+			pr_crit("unable to free bnode %u. bmap not found!\n",
+				node->this);
+			hfs_bnode_put(node);
+			return;
+		}
+		hfs_bnode_put(node);
+		node = hfs_bnode_find(tree, i);
+		if (IS_ERR(node))
+			return;
+		if (node->type != HFS_NODE_MAP) {
+			/* panic */;
+			pr_crit("invalid bmap found! (%u,%d)\n",
+				node->this, node->type);
+			hfs_bnode_put(node);
+			return;
+		}
+		len = hfs_brec_lenoff(node, 0, &off);
+	}
+
+	res = hfs_bmap_clear_bit(node, nidx);
+	if (res == -EINVAL) {
+		pr_crit("trying to free free bnode %u(%d)\n",
+			nidx, node->type);
+	} else if (res) {
+		pr_crit("fail to free bnode %u(%d)\n",
+			nidx, node->type);
+	} else {
+		tree->free_nodes++;
+		mark_inode_dirty(tree->inode);
+	}
+
+	hfs_bnode_put(node);
+}
diff --git a/fs/hfs/btree.h b/fs/hfs/btree.h
new file mode 100644
index 000000000..b4c3f2a31
--- /dev/null
+++ b/fs/hfs/btree.h
@@ -0,0 +1,171 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  linux/fs/hfs/btree.h
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ */
+
+#include "hfs_fs.h"
+
+typedef int (*btree_keycmp)(const btree_key *, const btree_key *);
+
+#define NODE_HASH_SIZE  256
+
+/* B-tree mutex nested subclasses */
+enum hfs_btree_mutex_classes {
+	CATALOG_BTREE_MUTEX,
+	EXTENTS_BTREE_MUTEX,
+	ATTR_BTREE_MUTEX,
+};
+
+/* A HFS BTree held in memory */
+struct hfs_btree {
+	struct super_block *sb;
+	struct inode *inode;
+	btree_keycmp keycmp;
+
+	u32 cnid;
+	u32 root;
+	u32 leaf_count;
+	u32 leaf_head;
+	u32 leaf_tail;
+	u32 node_count;
+	u32 free_nodes;
+	u32 attributes;
+
+	unsigned int node_size;
+	unsigned int node_size_shift;
+	unsigned int max_key_len;
+	unsigned int depth;
+
+	//unsigned int map1_size, map_size;
+	struct mutex tree_lock;
+
+	unsigned int pages_per_bnode;
+	spinlock_t hash_lock;
+	struct hfs_bnode *node_hash[NODE_HASH_SIZE];
+	int node_hash_cnt;
+};
+
+/* A HFS BTree node in memory */
+struct hfs_bnode {
+	struct hfs_btree *tree;
+
+	u32 prev;
+	u32 this;
+	u32 next;
+	u32 parent;
+
+	u16 num_recs;
+	u8 type;
+	u8 height;
+
+	struct hfs_bnode *next_hash;
+	unsigned long flags;
+	wait_queue_head_t lock_wq;
+	atomic_t refcnt;
+	unsigned int page_offset;
+	struct page *page[];
+};
+
+#define HFS_BNODE_ERROR		0
+#define HFS_BNODE_NEW		1
+#define HFS_BNODE_DELETED	2
+
+struct hfs_find_data {
+	btree_key *key;
+	btree_key *search_key;
+	struct hfs_btree *tree;
+	struct hfs_bnode *bnode;
+	int record;
+	int keyoffset, keylength;
+	int entryoffset, entrylength;
+};
+
+
+/* btree.c */
+extern struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id,
+					btree_keycmp keycmp);
+extern void hfs_btree_close(struct hfs_btree *tree);
+extern void hfs_btree_write(struct hfs_btree *tree);
+extern int hfs_bmap_reserve(struct hfs_btree *tree, u32 rsvd_nodes);
+extern struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree);
+extern void hfs_bmap_free(struct hfs_bnode *node);
+
+/* bnode.c */
+extern void hfs_bnode_read(struct hfs_bnode *node, void *buf, u32 off, u32 len);
+extern u16 hfs_bnode_read_u16(struct hfs_bnode *node, u32 off);
+extern u8 hfs_bnode_read_u8(struct hfs_bnode *node, u32 off);
+extern void hfs_bnode_read_key(struct hfs_bnode *node, void *key, u32 off);
+extern void hfs_bnode_write(struct hfs_bnode *node, void *buf, u32 off, u32 len);
+extern void hfs_bnode_write_u16(struct hfs_bnode *node, u32 off, u16 data);
+extern void hfs_bnode_write_u8(struct hfs_bnode *node, u32 off, u8 data);
+extern void hfs_bnode_clear(struct hfs_bnode *node, u32 off, u32 len);
+extern void hfs_bnode_copy(struct hfs_bnode *dst_node, u32 dst,
+			   struct hfs_bnode *src_node, u32 src, u32 len);
+extern void hfs_bnode_move(struct hfs_bnode *node, u32 dst, u32 src, u32 len);
+extern void hfs_bnode_dump(struct hfs_bnode *node);
+extern void hfs_bnode_unlink(struct hfs_bnode *node);
+extern struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid);
+extern struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num);
+extern void hfs_bnode_unhash(struct hfs_bnode *node);
+extern void hfs_bnode_free(struct hfs_bnode *node);
+extern struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num);
+extern void hfs_bnode_get(struct hfs_bnode *node);
+extern void hfs_bnode_put(struct hfs_bnode *node);
+
+/* brec.c */
+extern u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off);
+extern u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec);
+extern int hfs_brec_insert(struct hfs_find_data *fd, void *entry, u32 entry_len);
+extern int hfs_brec_remove(struct hfs_find_data *fd);
+
+/* bfind.c */
+extern int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd);
+extern void hfs_find_exit(struct hfs_find_data *fd);
+extern int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd);
+extern int hfs_brec_find(struct hfs_find_data *fd);
+extern int hfs_brec_read(struct hfs_find_data *fd, void *rec, u32 rec_len);
+extern int hfs_brec_goto(struct hfs_find_data *fd, int cnt);
+
+static inline bool is_bnode_offset_valid(struct hfs_bnode *node, u32 off)
+{
+	bool is_valid;
+
+	if (!node || !node->tree)
+		return false;
+
+	is_valid = off < node->tree->node_size;
+
+	if (!is_valid) {
+		pr_err("invalid offset: id %u, type %#x, h %u, sz %u, off %u\n",
+		       node->this, node->type, node->height,
+		       node->tree->node_size, off);
+	}
+
+	return is_valid;
+}
+
+static inline u32 check_and_correct_requested_length(struct hfs_bnode *node, u32 off, u32 len)
+{
+	unsigned int node_size;
+
+	if (!is_bnode_offset_valid(node, off))
+		return 0;
+
+	node_size = node->tree->node_size;
+
+	if ((u64)off + len > node_size) {
+		u32 new_len = node_size - off;
+
+		pr_err("corrected len: id %u, type %#x, h %u, sz %u, off %u, len %u->%u\n",
+		       node->this, node->type, node->height,
+		       node_size, off, len, new_len);
+
+		return new_len;
+	}
+
+	return len;
+}
diff --git a/fs/hfs/catalog.c b/fs/hfs/catalog.c
new file mode 100644
index 000000000..490c5e130
--- /dev/null
+++ b/fs/hfs/catalog.c
@@ -0,0 +1,536 @@
+/*
+ *  linux/fs/hfs/catalog.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains the functions related to the catalog B-tree.
+ *
+ * Cache code shamelessly stolen from
+ *     linux/fs/inode.c Copyright (C) 1991, 1992  Linus Torvalds
+ *     re-shamelessly stolen Copyright (C) 1997 Linus Torvalds
+ */
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+/*
+ * hfs_cat_build_key()
+ *
+ * Given the ID of the parent and the name build a search key.
+ */
+void hfs_cat_build_key(struct super_block *sb, btree_key *key, u32 parent, const struct qstr *name)
+{
+	key->cat.reserved = 0;
+	key->cat.ParID = cpu_to_be32(parent);
+	if (name) {
+		hfs_asc2mac(sb, &key->cat.CName, name);
+		key->key_len = 6 + key->cat.CName.len;
+	} else {
+		memset(&key->cat.CName, 0, sizeof(struct hfs_name));
+		key->key_len = 6;
+	}
+}
+
+static int hfs_cat_build_record(hfs_cat_rec *rec, u32 cnid, struct inode *inode)
+{
+	__be32 mtime = hfs_mtime();
+
+	memset(rec, 0, sizeof(*rec));
+	if (S_ISDIR(inode->i_mode)) {
+		rec->type = HFS_CDR_DIR;
+		rec->dir.DirID = cpu_to_be32(cnid);
+		rec->dir.CrDat = mtime;
+		rec->dir.MdDat = mtime;
+		rec->dir.BkDat = 0;
+		rec->dir.UsrInfo.frView = cpu_to_be16(0xff);
+		return sizeof(struct hfs_cat_dir);
+	} else {
+		/* init some fields for the file record */
+		rec->type = HFS_CDR_FIL;
+		rec->file.Flags = HFS_FIL_USED | HFS_FIL_THD;
+		if (!(inode->i_mode & S_IWUSR))
+			rec->file.Flags |= HFS_FIL_LOCK;
+		rec->file.FlNum = cpu_to_be32(cnid);
+		rec->file.CrDat = mtime;
+		rec->file.MdDat = mtime;
+		rec->file.BkDat = 0;
+		rec->file.UsrWds.fdType = HFS_SB(inode->i_sb)->s_type;
+		rec->file.UsrWds.fdCreator = HFS_SB(inode->i_sb)->s_creator;
+		return sizeof(struct hfs_cat_file);
+	}
+}
+
+static int hfs_cat_build_thread(struct super_block *sb,
+				hfs_cat_rec *rec, int type,
+				u32 parentid, const struct qstr *name)
+{
+	rec->type = type;
+	memset(rec->thread.reserved, 0, sizeof(rec->thread.reserved));
+	rec->thread.ParID = cpu_to_be32(parentid);
+	hfs_asc2mac(sb, &rec->thread.CName, name);
+	return sizeof(struct hfs_cat_thread);
+}
+
+/*
+ * create_entry()
+ *
+ * Add a new file or directory to the catalog B-tree and
+ * return a (struct hfs_cat_entry) for it in '*result'.
+ */
+int hfs_cat_create(u32 cnid, struct inode *dir, const struct qstr *str, struct inode *inode)
+{
+	struct hfs_find_data fd;
+	struct super_block *sb;
+	union hfs_cat_rec entry;
+	int entry_size;
+	int err;
+
+	hfs_dbg("name %s, cnid %u, i_nlink %d\n",
+		str->name, cnid, inode->i_nlink);
+	if (dir->i_size >= HFS_MAX_VALENCE)
+		return -ENOSPC;
+
+	sb = dir->i_sb;
+	err = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
+	if (err)
+		return err;
+
+	/*
+	 * Fail early and avoid ENOSPC during the btree operations. We may
+	 * have to split the root node at most once.
+	 */
+	err = hfs_bmap_reserve(fd.tree, 2 * fd.tree->depth);
+	if (err)
+		goto err2;
+
+	hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
+	entry_size = hfs_cat_build_thread(sb, &entry, S_ISDIR(inode->i_mode) ?
+			HFS_CDR_THD : HFS_CDR_FTH,
+			dir->i_ino, str);
+	err = hfs_brec_find(&fd);
+	if (err != -ENOENT) {
+		if (!err)
+			err = -EEXIST;
+		goto err2;
+	}
+	err = hfs_brec_insert(&fd, &entry, entry_size);
+	if (err)
+		goto err2;
+
+	hfs_cat_build_key(sb, fd.search_key, dir->i_ino, str);
+	entry_size = hfs_cat_build_record(&entry, cnid, inode);
+	err = hfs_brec_find(&fd);
+	if (err != -ENOENT) {
+		/* panic? */
+		if (!err)
+			err = -EEXIST;
+		goto err1;
+	}
+	err = hfs_brec_insert(&fd, &entry, entry_size);
+	if (err)
+		goto err1;
+
+	dir->i_size++;
+	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+	mark_inode_dirty(dir);
+	hfs_find_exit(&fd);
+	return 0;
+
+err1:
+	hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
+	if (!hfs_brec_find(&fd))
+		hfs_brec_remove(&fd);
+err2:
+	hfs_find_exit(&fd);
+	return err;
+}
+
+/*
+ * hfs_cat_compare()
+ *
+ * Description:
+ *   This is the comparison function used for the catalog B-tree.  In
+ *   comparing catalog B-tree entries, the parent id is the most
+ *   significant field (compared as unsigned ints).  The name field is
+ *   the least significant (compared in "Macintosh lexical order",
+ *   see hfs_strcmp() in string.c)
+ * Input Variable(s):
+ *   struct hfs_cat_key *key1: pointer to the first key to compare
+ *   struct hfs_cat_key *key2: pointer to the second key to compare
+ * Output Variable(s):
+ *   NONE
+ * Returns:
+ *   int: negative if key1<key2, positive if key1>key2, and 0 if key1==key2
+ * Preconditions:
+ *   key1 and key2 point to "valid" (struct hfs_cat_key)s.
+ * Postconditions:
+ *   This function has no side-effects
+ */
+int hfs_cat_keycmp(const btree_key *key1, const btree_key *key2)
+{
+	__be32 k1p, k2p;
+
+	k1p = key1->cat.ParID;
+	k2p = key2->cat.ParID;
+
+	if (k1p != k2p)
+		return be32_to_cpu(k1p) < be32_to_cpu(k2p) ? -1 : 1;
+
+	return hfs_strcmp(key1->cat.CName.name, key1->cat.CName.len,
+			  key2->cat.CName.name, key2->cat.CName.len);
+}
+
+static int hfs_cat_validate_found_cnid(struct hfs_find_data *fd, u32 cnid)
+{
+	hfs_cat_rec rec;
+	u32 found_cnid;
+	int rec_len;
+
+	rec_len = fd->entrylength;
+	if (rec_len <= 0 || (size_t)rec_len > sizeof(rec))
+		return -EIO;
+
+	memset(&rec, 0, sizeof(rec));
+	hfs_bnode_read(fd->bnode, &rec, fd->entryoffset, rec_len);
+
+	switch (rec.type) {
+	case HFS_CDR_FIL:
+		if ((size_t)rec_len != sizeof(struct hfs_cat_file))
+			return -EIO;
+		found_cnid = be32_to_cpu(rec.file.FlNum);
+		break;
+	case HFS_CDR_DIR:
+		if ((size_t)rec_len != sizeof(struct hfs_cat_dir))
+			return -EIO;
+		found_cnid = be32_to_cpu(rec.dir.DirID);
+		break;
+	default:
+		return -EIO;
+	}
+
+	if (found_cnid != cnid)
+		return -EIO;
+
+	return 0;
+}
+
+/* Try to get a catalog entry for given catalog id */
+// move to read_super???
+int hfs_cat_find_brec(struct super_block *sb, u32 cnid,
+		      struct hfs_find_data *fd)
+{
+	hfs_cat_rec rec;
+	int res, len, type;
+
+	hfs_cat_build_key(sb, fd->search_key, cnid, NULL);
+	res = hfs_brec_read(fd, &rec, sizeof(rec));
+	if (res)
+		return res;
+
+	type = rec.type;
+	if (type != HFS_CDR_THD && type != HFS_CDR_FTH) {
+		pr_err("found bad thread record in catalog\n");
+		return -EIO;
+	}
+
+	fd->search_key->cat.ParID = rec.thread.ParID;
+	len = fd->search_key->cat.CName.len = rec.thread.CName.len;
+	if (len > HFS_NAMELEN) {
+		pr_err("bad catalog namelength\n");
+		return -EIO;
+	}
+	memcpy(fd->search_key->cat.CName.name, rec.thread.CName.name, len);
+
+	res = hfs_brec_find(fd);
+	if (res)
+		return res;
+
+	return hfs_cat_validate_found_cnid(fd, cnid);
+}
+
+static inline
+void hfs_set_next_unused_CNID(struct super_block *sb,
+				u32 deleted_cnid, u32 found_cnid)
+{
+	if (found_cnid < HFS_FIRSTUSER_CNID) {
+		atomic64_cmpxchg(&HFS_SB(sb)->next_id,
+				 deleted_cnid + 1, HFS_FIRSTUSER_CNID);
+	} else {
+		atomic64_cmpxchg(&HFS_SB(sb)->next_id,
+				 deleted_cnid + 1, found_cnid + 1);
+	}
+}
+
+/*
+ * hfs_correct_next_unused_CNID()
+ *
+ * Correct the next unused CNID of Catalog Tree.
+ */
+static
+int hfs_correct_next_unused_CNID(struct super_block *sb, u32 cnid)
+{
+	struct hfs_btree *cat_tree;
+	struct hfs_bnode *node;
+	s64 leaf_head;
+	s64 leaf_tail;
+	s64 node_id;
+
+	hfs_dbg("cnid %u, next_id %lld\n",
+		cnid, atomic64_read(&HFS_SB(sb)->next_id));
+
+	if ((cnid + 1) < atomic64_read(&HFS_SB(sb)->next_id)) {
+		/* next ID should be unchanged */
+		return 0;
+	}
+
+	cat_tree = HFS_SB(sb)->cat_tree;
+	leaf_head = cat_tree->leaf_head;
+	leaf_tail = cat_tree->leaf_tail;
+
+	if (leaf_head > leaf_tail) {
+		pr_err("node is corrupted: leaf_head %lld, leaf_tail %lld\n",
+			leaf_head, leaf_tail);
+		return -ERANGE;
+	}
+
+	node = hfs_bnode_find(cat_tree, leaf_tail);
+	if (IS_ERR(node)) {
+		pr_err("fail to find leaf node: node ID %lld\n",
+			leaf_tail);
+		return -ENOENT;
+	}
+
+	node_id = leaf_tail;
+
+	do {
+		int i;
+
+		if (node_id != leaf_tail) {
+			node = hfs_bnode_find(cat_tree, node_id);
+			if (IS_ERR(node))
+				return -ENOENT;
+		}
+
+		hfs_dbg("node %lld, leaf_tail %lld, leaf_head %lld\n",
+			node_id, leaf_tail, leaf_head);
+
+		hfs_bnode_dump(node);
+
+		for (i = node->num_recs - 1; i >= 0; i--) {
+			hfs_cat_rec rec;
+			u16 off, len, keylen;
+			int entryoffset;
+			int entrylength;
+			u32 found_cnid;
+
+			len = hfs_brec_lenoff(node, i, &off);
+			keylen = hfs_brec_keylen(node, i);
+			if (keylen == 0) {
+				pr_err("fail to get the keylen: "
+					"node_id %lld, record index %d\n",
+					node_id, i);
+				return -EINVAL;
+			}
+
+			entryoffset = off + keylen;
+			entrylength = len - keylen;
+
+			if (entrylength > sizeof(rec)) {
+				pr_err("unexpected record length: "
+					"entrylength %d\n",
+					entrylength);
+				return -EINVAL;
+			}
+
+			hfs_bnode_read(node, &rec, entryoffset, entrylength);
+
+			if (rec.type == HFS_CDR_DIR) {
+				found_cnid = be32_to_cpu(rec.dir.DirID);
+				hfs_dbg("found_cnid %u\n", found_cnid);
+				hfs_set_next_unused_CNID(sb, cnid, found_cnid);
+				hfs_bnode_put(node);
+				return 0;
+			} else if (rec.type == HFS_CDR_FIL) {
+				found_cnid = be32_to_cpu(rec.file.FlNum);
+				hfs_dbg("found_cnid %u\n", found_cnid);
+				hfs_set_next_unused_CNID(sb, cnid, found_cnid);
+				hfs_bnode_put(node);
+				return 0;
+			}
+		}
+
+		node_id = node->prev;
+		hfs_bnode_put(node);
+
+	} while (node_id >= leaf_head);
+
+	return -ENOENT;
+}
+
+/*
+ * hfs_cat_delete()
+ *
+ * Delete the indicated file or directory.
+ * The associated thread is also removed unless ('with_thread'==0).
+ */
+int hfs_cat_delete(u32 cnid, struct inode *dir, const struct qstr *str)
+{
+	struct super_block *sb;
+	struct hfs_find_data fd;
+	int res, type;
+
+	hfs_dbg("name %s, cnid %u\n", str ? str->name : NULL, cnid);
+	sb = dir->i_sb;
+	res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
+	if (res)
+		return res;
+
+	hfs_cat_build_key(sb, fd.search_key, dir->i_ino, str);
+	res = hfs_brec_find(&fd);
+	if (res)
+		goto out;
+
+	type = hfs_bnode_read_u8(fd.bnode, fd.entryoffset);
+	if (type == HFS_CDR_FIL) {
+		struct hfs_cat_file file;
+		hfs_bnode_read(fd.bnode, &file, fd.entryoffset, sizeof(file));
+		if (be32_to_cpu(file.FlNum) == cnid) {
+#if 0
+			hfs_free_fork(sb, &file, HFS_FK_DATA);
+#endif
+			hfs_free_fork(sb, &file, HFS_FK_RSRC);
+		}
+	}
+
+	res = hfs_brec_remove(&fd);
+	if (res)
+		goto out;
+
+	hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
+	res = hfs_brec_find(&fd);
+	if (!res) {
+		res = hfs_brec_remove(&fd);
+		if (res)
+			goto out;
+	}
+
+	dir->i_size--;
+	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+	mark_inode_dirty(dir);
+
+	res = hfs_correct_next_unused_CNID(sb, cnid);
+	if (res)
+		goto out;
+
+	res = 0;
+out:
+	hfs_find_exit(&fd);
+
+	return res;
+}
+
+/*
+ * hfs_cat_move()
+ *
+ * Rename a file or directory, possibly to a new directory.
+ * If the destination exists it is removed and a
+ * (struct hfs_cat_entry) for it is returned in '*result'.
+ */
+int hfs_cat_move(u32 cnid, struct inode *src_dir, const struct qstr *src_name,
+		 struct inode *dst_dir, const struct qstr *dst_name)
+{
+	struct super_block *sb;
+	struct hfs_find_data src_fd, dst_fd;
+	union hfs_cat_rec entry;
+	int entry_size, type;
+	int err;
+
+	hfs_dbg("cnid %u - (ino %llu, name %s) - (ino %llu, name %s)\n",
+		cnid, src_dir->i_ino, src_name->name,
+		dst_dir->i_ino, dst_name->name);
+	sb = src_dir->i_sb;
+	err = hfs_find_init(HFS_SB(sb)->cat_tree, &src_fd);
+	if (err)
+		return err;
+	dst_fd = src_fd;
+
+	/*
+	 * Fail early and avoid ENOSPC during the btree operations. We may
+	 * have to split the root node at most once.
+	 */
+	err = hfs_bmap_reserve(src_fd.tree, 2 * src_fd.tree->depth);
+	if (err)
+		goto out;
+
+	/* find the old dir entry and read the data */
+	hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
+	err = hfs_brec_find(&src_fd);
+	if (err)
+		goto out;
+	if (src_fd.entrylength > sizeof(entry) || src_fd.entrylength < 0) {
+		err = -EIO;
+		goto out;
+	}
+
+	hfs_bnode_read(src_fd.bnode, &entry, src_fd.entryoffset,
+			    src_fd.entrylength);
+
+	/* create new dir entry with the data from the old entry */
+	hfs_cat_build_key(sb, dst_fd.search_key, dst_dir->i_ino, dst_name);
+	err = hfs_brec_find(&dst_fd);
+	if (err != -ENOENT) {
+		if (!err)
+			err = -EEXIST;
+		goto out;
+	}
+
+	err = hfs_brec_insert(&dst_fd, &entry, src_fd.entrylength);
+	if (err)
+		goto out;
+	dst_dir->i_size++;
+	inode_set_mtime_to_ts(dst_dir, inode_set_ctime_current(dst_dir));
+	mark_inode_dirty(dst_dir);
+
+	/* finally remove the old entry */
+	hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
+	err = hfs_brec_find(&src_fd);
+	if (err)
+		goto out;
+	err = hfs_brec_remove(&src_fd);
+	if (err)
+		goto out;
+	src_dir->i_size--;
+	inode_set_mtime_to_ts(src_dir, inode_set_ctime_current(src_dir));
+	mark_inode_dirty(src_dir);
+
+	type = entry.type;
+	if (type == HFS_CDR_FIL && !(entry.file.Flags & HFS_FIL_THD))
+		goto out;
+
+	/* remove old thread entry */
+	hfs_cat_build_key(sb, src_fd.search_key, cnid, NULL);
+	err = hfs_brec_find(&src_fd);
+	if (err)
+		goto out;
+	err = hfs_brec_remove(&src_fd);
+	if (err)
+		goto out;
+
+	/* create new thread entry */
+	hfs_cat_build_key(sb, dst_fd.search_key, cnid, NULL);
+	entry_size = hfs_cat_build_thread(sb, &entry, type == HFS_CDR_FIL ? HFS_CDR_FTH : HFS_CDR_THD,
+					dst_dir->i_ino, dst_name);
+	err = hfs_brec_find(&dst_fd);
+	if (err != -ENOENT) {
+		if (!err)
+			err = -EEXIST;
+		goto out;
+	}
+	err = hfs_brec_insert(&dst_fd, &entry, entry_size);
+out:
+	hfs_bnode_put(dst_fd.bnode);
+	hfs_find_exit(&src_fd);
+	return err;
+}
diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c
new file mode 100644
index 000000000..e1f1fb351
--- /dev/null
+++ b/fs/hfs/dir.c
@@ -0,0 +1,331 @@
+/*
+ *  linux/fs/hfs/dir.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains directory-related functions independent of which
+ * scheme is being used to represent forks.
+ *
+ * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
+ */
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+/*
+ * hfs_lookup()
+ */
+static struct dentry *hfs_lookup(struct inode *dir, struct dentry *dentry,
+				 unsigned int flags)
+{
+	hfs_cat_rec rec;
+	struct hfs_find_data fd;
+	struct inode *inode = NULL;
+	int res;
+
+	res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
+	if (res)
+		return ERR_PTR(res);
+	hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name);
+	res = hfs_brec_read(&fd, &rec, sizeof(rec));
+	if (res) {
+		if (res != -ENOENT)
+			inode = ERR_PTR(res);
+	} else {
+		inode = hfs_iget(dir->i_sb, &fd.search_key->cat, &rec);
+		if (!inode)
+			inode = ERR_PTR(-EACCES);
+	}
+	hfs_find_exit(&fd);
+	return d_splice_alias(inode, dentry);
+}
+
+/*
+ * hfs_readdir
+ */
+static int hfs_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct inode *inode = file_inode(file);
+	struct super_block *sb = inode->i_sb;
+	int len, err;
+	char strbuf[HFS_MAX_NAMELEN];
+	union hfs_cat_rec entry;
+	struct hfs_find_data fd;
+	struct hfs_readdir_data *rd;
+	u16 type;
+
+	if (ctx->pos >= inode->i_size)
+		return 0;
+
+	err = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
+	if (err)
+		return err;
+	hfs_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
+	err = hfs_brec_find(&fd);
+	if (err)
+		goto out;
+
+	if (ctx->pos == 0) {
+		/* This is completely artificial... */
+		if (!dir_emit_dot(file, ctx))
+			goto out;
+		ctx->pos = 1;
+	}
+	if (ctx->pos == 1) {
+		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
+			err = -EIO;
+			goto out;
+		}
+
+		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
+		if (entry.type != HFS_CDR_THD) {
+			pr_err("bad catalog folder thread\n");
+			err = -EIO;
+			goto out;
+		}
+		//if (fd.entrylength < HFS_MIN_THREAD_SZ) {
+		//	pr_err("truncated catalog thread\n");
+		//	err = -EIO;
+		//	goto out;
+		//}
+		if (!dir_emit(ctx, "..", 2,
+			    be32_to_cpu(entry.thread.ParID), DT_DIR))
+			goto out;
+		ctx->pos = 2;
+	}
+	if (ctx->pos >= inode->i_size)
+		goto out;
+	rd = file->private_data;
+	if (rd && rd->pos == ctx->pos) {
+		memcpy(fd.search_key, &rd->key, sizeof(struct hfs_cat_key));
+		err = hfs_brec_find(&fd);
+		if (err == -ENOENT)
+			err = hfs_brec_goto(&fd, 1);
+	} else {
+		err = hfs_brec_goto(&fd, ctx->pos - 1);
+	}
+	if (err)
+		goto out;
+
+	for (;;) {
+		if (be32_to_cpu(fd.key->cat.ParID) != inode->i_ino) {
+			pr_err("walked past end of dir\n");
+			err = -EIO;
+			goto out;
+		}
+
+		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
+			err = -EIO;
+			goto out;
+		}
+
+		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
+		type = entry.type;
+		len = hfs_mac2asc(sb, strbuf, &fd.key->cat.CName);
+		if (type == HFS_CDR_DIR) {
+			if (fd.entrylength < sizeof(struct hfs_cat_dir)) {
+				pr_err("small dir entry\n");
+				err = -EIO;
+				goto out;
+			}
+			if (!dir_emit(ctx, strbuf, len,
+				    be32_to_cpu(entry.dir.DirID), DT_DIR))
+				break;
+		} else if (type == HFS_CDR_FIL) {
+			if (fd.entrylength < sizeof(struct hfs_cat_file)) {
+				pr_err("small file entry\n");
+				err = -EIO;
+				goto out;
+			}
+			if (!dir_emit(ctx, strbuf, len,
+				    be32_to_cpu(entry.file.FlNum), DT_REG))
+				break;
+		} else {
+			pr_err("bad catalog entry type %d\n", type);
+			err = -EIO;
+			goto out;
+		}
+		ctx->pos++;
+		if (ctx->pos >= inode->i_size)
+			goto out;
+		err = hfs_brec_goto(&fd, 1);
+		if (err)
+			goto out;
+	}
+	if (!rd) {
+		rd = kmalloc_obj(struct hfs_readdir_data);
+		if (!rd) {
+			err = -ENOMEM;
+			goto out;
+		}
+		file->private_data = rd;
+	}
+	rd->pos = ctx->pos;
+	memcpy(&rd->key, &fd.key->cat, sizeof(struct hfs_cat_key));
+out:
+	hfs_find_exit(&fd);
+	return err;
+}
+
+static int hfs_dir_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	return 0;
+}
+
+/*
+ * hfs_create()
+ *
+ * This is the create() entry in the inode_operations structure for
+ * regular HFS directories.  The purpose is to create a new file in
+ * a directory and return a corresponding inode, given the inode for
+ * the directory and the name (and its length) of the new file.
+ */
+static int hfs_create(struct mnt_idmap *idmap, struct inode *dir,
+		      struct dentry *dentry, umode_t mode)
+{
+	struct inode *inode;
+	int res;
+
+	inode = hfs_new_inode(dir, &dentry->d_name, mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
+	if (res) {
+		clear_nlink(inode);
+		hfs_delete_inode(inode);
+		iput(inode);
+		return res;
+	}
+	d_instantiate(dentry, inode);
+	mark_inode_dirty(inode);
+	return 0;
+}
+
+/*
+ * hfs_mkdir()
+ *
+ * This is the mkdir() entry in the inode_operations structure for
+ * regular HFS directories.  The purpose is to create a new directory
+ * in a directory, given the inode for the parent directory and the
+ * name (and its length) of the new directory.
+ */
+static struct dentry *hfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+				struct dentry *dentry, umode_t mode)
+{
+	struct inode *inode;
+	int res;
+
+	inode = hfs_new_inode(dir, &dentry->d_name, mode);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+
+	res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
+	if (res) {
+		clear_nlink(inode);
+		hfs_delete_inode(inode);
+		iput(inode);
+		return ERR_PTR(res);
+	}
+	d_instantiate(dentry, inode);
+	mark_inode_dirty(inode);
+	return NULL;
+}
+
+/*
+ * hfs_remove()
+ *
+ * This serves as both unlink() and rmdir() in the inode_operations
+ * structure for regular HFS directories.  The purpose is to delete
+ * an existing child, given the inode for the parent directory and
+ * the name (and its length) of the existing directory.
+ *
+ * HFS does not have hardlinks, so both rmdir and unlink set the
+ * link count to 0.  The only difference is the emptiness check.
+ */
+static int hfs_remove(struct inode *dir, struct dentry *dentry)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode = d_inode(dentry);
+	int res;
+
+	if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
+		return -ENOTEMPTY;
+
+	if (unlikely(!is_hfs_cnid_counts_valid(sb))) {
+	    pr_err("cannot remove file/folder\n");
+	    return -ERANGE;
+	}
+
+	res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
+	if (res)
+		return res;
+	clear_nlink(inode);
+	inode_set_ctime_current(inode);
+	hfs_delete_inode(inode);
+	mark_inode_dirty(inode);
+	return 0;
+}
+
+/*
+ * hfs_rename()
+ *
+ * This is the rename() entry in the inode_operations structure for
+ * regular HFS directories.  The purpose is to rename an existing
+ * file or directory, given the inode for the current directory and
+ * the name (and its length) of the existing file/directory and the
+ * inode for the new directory and the name (and its length) of the
+ * new file/directory.
+ * XXX: how do you handle must_be dir?
+ */
+static int hfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
+		      struct dentry *old_dentry, struct inode *new_dir,
+		      struct dentry *new_dentry, unsigned int flags)
+{
+	int res;
+
+	if (flags & ~RENAME_NOREPLACE)
+		return -EINVAL;
+
+	/* Unlink destination if it already exists */
+	if (d_really_is_positive(new_dentry)) {
+		res = hfs_remove(new_dir, new_dentry);
+		if (res)
+			return res;
+	}
+
+	res = hfs_cat_move(d_inode(old_dentry)->i_ino,
+			   old_dir, &old_dentry->d_name,
+			   new_dir, &new_dentry->d_name);
+	if (!res) {
+		struct inode *inode = d_inode(old_dentry);
+
+		hfs_cat_build_key(old_dir->i_sb,
+				  (btree_key *)&HFS_I(inode)->cat_key,
+				  new_dir->i_ino, &new_dentry->d_name);
+		inode_set_ctime_current(inode);
+		mark_inode_dirty(inode);
+	}
+	return res;
+}
+
+const struct file_operations hfs_dir_operations = {
+	.read		= generic_read_dir,
+	.iterate_shared	= hfs_readdir,
+	.llseek		= generic_file_llseek,
+	.release	= hfs_dir_release,
+};
+
+const struct inode_operations hfs_dir_inode_operations = {
+	.create		= hfs_create,
+	.lookup		= hfs_lookup,
+	.unlink		= hfs_remove,
+	.mkdir		= hfs_mkdir,
+	.rmdir		= hfs_remove,
+	.rename		= hfs_rename,
+	.setattr	= hfs_inode_setattr,
+	.fileattr_get	= hfs_fileattr_get,
+};
diff --git a/fs/hfs/extent.c b/fs/hfs/extent.c
new file mode 100644
index 000000000..f066a99a8
--- /dev/null
+++ b/fs/hfs/extent.c
@@ -0,0 +1,552 @@
+/*
+ *  linux/fs/hfs/extent.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains the functions related to the extents B-tree.
+ */
+
+#include <linux/pagemap.h>
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+/*================ File-local functions ================*/
+
+/*
+ * build_key
+ */
+static void hfs_ext_build_key(hfs_btree_key *key, u32 cnid, u16 block, u8 type)
+{
+	key->key_len = 7;
+	key->ext.FkType = type;
+	key->ext.FNum = cpu_to_be32(cnid);
+	key->ext.FABN = cpu_to_be16(block);
+}
+
+/*
+ * hfs_ext_compare()
+ *
+ * Description:
+ *   This is the comparison function used for the extents B-tree.  In
+ *   comparing extent B-tree entries, the file id is the most
+ *   significant field (compared as unsigned ints); the fork type is
+ *   the second most significant field (compared as unsigned chars);
+ *   and the allocation block number field is the least significant
+ *   (compared as unsigned ints).
+ * Input Variable(s):
+ *   struct hfs_ext_key *key1: pointer to the first key to compare
+ *   struct hfs_ext_key *key2: pointer to the second key to compare
+ * Output Variable(s):
+ *   NONE
+ * Returns:
+ *   int: negative if key1<key2, positive if key1>key2, and 0 if key1==key2
+ * Preconditions:
+ *   key1 and key2 point to "valid" (struct hfs_ext_key)s.
+ * Postconditions:
+ *   This function has no side-effects */
+int hfs_ext_keycmp(const btree_key *key1, const btree_key *key2)
+{
+	__be32 fnum1, fnum2;
+	__be16 block1, block2;
+
+	fnum1 = key1->ext.FNum;
+	fnum2 = key2->ext.FNum;
+	if (fnum1 != fnum2)
+		return be32_to_cpu(fnum1) < be32_to_cpu(fnum2) ? -1 : 1;
+	if (key1->ext.FkType != key2->ext.FkType)
+		return key1->ext.FkType < key2->ext.FkType ? -1 : 1;
+
+	block1 = key1->ext.FABN;
+	block2 = key2->ext.FABN;
+	if (block1 == block2)
+		return 0;
+	return be16_to_cpu(block1) < be16_to_cpu(block2) ? -1 : 1;
+}
+
+/*
+ * hfs_ext_find_block
+ *
+ * Find a block within an extent record
+ */
+u16 hfs_ext_find_block(struct hfs_extent *ext, u16 off)
+{
+	int i;
+	u16 count;
+
+	for (i = 0; i < 3; ext++, i++) {
+		count = be16_to_cpu(ext->count);
+		if (off < count)
+			return be16_to_cpu(ext->block) + off;
+		off -= count;
+	}
+	/* panic? */
+	return 0;
+}
+
+static int hfs_ext_block_count(struct hfs_extent *ext)
+{
+	int i;
+	u16 count = 0;
+
+	for (i = 0; i < 3; ext++, i++)
+		count += be16_to_cpu(ext->count);
+	return count;
+}
+
+static u16 hfs_ext_lastblock(struct hfs_extent *ext)
+{
+	int i;
+
+	ext += 2;
+	for (i = 0; i < 2; ext--, i++)
+		if (ext->count)
+			break;
+	return be16_to_cpu(ext->block) + be16_to_cpu(ext->count);
+}
+
+static int __hfs_ext_write_extent(struct inode *inode, struct hfs_find_data *fd)
+{
+	int res;
+
+	hfs_ext_build_key(fd->search_key, inode->i_ino, HFS_I(inode)->cached_start,
+			  HFS_IS_RSRC(inode) ?  HFS_FK_RSRC : HFS_FK_DATA);
+	res = hfs_brec_find(fd);
+	if (HFS_I(inode)->flags & HFS_FLG_EXT_NEW) {
+		if (res != -ENOENT)
+			return res;
+		/* Fail early and avoid ENOSPC during the btree operation */
+		res = hfs_bmap_reserve(fd->tree, fd->tree->depth + 1);
+		if (res)
+			return res;
+		hfs_brec_insert(fd, HFS_I(inode)->cached_extents, sizeof(hfs_extent_rec));
+		HFS_I(inode)->flags &= ~(HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW);
+	} else {
+		if (res)
+			return res;
+		hfs_bnode_write(fd->bnode, HFS_I(inode)->cached_extents, fd->entryoffset, fd->entrylength);
+		HFS_I(inode)->flags &= ~HFS_FLG_EXT_DIRTY;
+	}
+	return 0;
+}
+
+int hfs_ext_write_extent(struct inode *inode)
+{
+	struct hfs_find_data fd;
+	int res = 0;
+
+	if (HFS_I(inode)->flags & HFS_FLG_EXT_DIRTY) {
+		res = hfs_find_init(HFS_SB(inode->i_sb)->ext_tree, &fd);
+		if (res)
+			return res;
+		res = __hfs_ext_write_extent(inode, &fd);
+		hfs_find_exit(&fd);
+	}
+	return res;
+}
+
+static inline int __hfs_ext_read_extent(struct hfs_find_data *fd, struct hfs_extent *extent,
+					u32 cnid, u32 block, u8 type)
+{
+	int res;
+
+	hfs_ext_build_key(fd->search_key, cnid, block, type);
+	fd->key->ext.FNum = 0;
+	res = hfs_brec_find(fd);
+	if (res && res != -ENOENT)
+		return res;
+	if (fd->key->ext.FNum != fd->search_key->ext.FNum ||
+	    fd->key->ext.FkType != fd->search_key->ext.FkType)
+		return -ENOENT;
+	if (fd->entrylength != sizeof(hfs_extent_rec))
+		return -EIO;
+	hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfs_extent_rec));
+	return 0;
+}
+
+static inline int __hfs_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block)
+{
+	int res;
+
+	if (HFS_I(inode)->flags & HFS_FLG_EXT_DIRTY) {
+		res = __hfs_ext_write_extent(inode, fd);
+		if (res)
+			return res;
+	}
+
+	res = __hfs_ext_read_extent(fd, HFS_I(inode)->cached_extents, inode->i_ino,
+				    block, HFS_IS_RSRC(inode) ? HFS_FK_RSRC : HFS_FK_DATA);
+	if (!res) {
+		HFS_I(inode)->cached_start = be16_to_cpu(fd->key->ext.FABN);
+		HFS_I(inode)->cached_blocks = hfs_ext_block_count(HFS_I(inode)->cached_extents);
+	} else {
+		HFS_I(inode)->cached_start = HFS_I(inode)->cached_blocks = 0;
+		HFS_I(inode)->flags &= ~(HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW);
+	}
+	return res;
+}
+
+static int hfs_ext_read_extent(struct inode *inode, u16 block)
+{
+	struct hfs_find_data fd;
+	int res;
+
+	if (block >= HFS_I(inode)->cached_start &&
+	    block < HFS_I(inode)->cached_start + HFS_I(inode)->cached_blocks)
+		return 0;
+
+	res = hfs_find_init(HFS_SB(inode->i_sb)->ext_tree, &fd);
+	if (!res) {
+		res = __hfs_ext_cache_extent(&fd, inode, block);
+		hfs_find_exit(&fd);
+	}
+	return res;
+}
+
+static void hfs_dump_extent(struct hfs_extent *extent)
+{
+	int i;
+
+	hfs_dbg("extent:   ");
+	for (i = 0; i < 3; i++)
+		hfs_dbg(" block %u, count %u",
+			be16_to_cpu(extent[i].block),
+			be16_to_cpu(extent[i].count));
+	hfs_dbg("\n");
+}
+
+static int hfs_add_extent(struct hfs_extent *extent, u16 offset,
+			  u16 alloc_block, u16 block_count)
+{
+	u16 count, start;
+	int i;
+
+	hfs_dump_extent(extent);
+	for (i = 0; i < 3; extent++, i++) {
+		count = be16_to_cpu(extent->count);
+		if (offset == count) {
+			start = be16_to_cpu(extent->block);
+			if (alloc_block != start + count) {
+				if (++i >= 3)
+					return -ENOSPC;
+				extent++;
+				extent->block = cpu_to_be16(alloc_block);
+			} else
+				block_count += count;
+			extent->count = cpu_to_be16(block_count);
+			return 0;
+		} else if (offset < count)
+			break;
+		offset -= count;
+	}
+	/* panic? */
+	return -EIO;
+}
+
+static int hfs_free_extents(struct super_block *sb, struct hfs_extent *extent,
+			    u16 offset, u16 block_nr)
+{
+	u16 count, start;
+	int i;
+
+	hfs_dump_extent(extent);
+	for (i = 0; i < 3; extent++, i++) {
+		count = be16_to_cpu(extent->count);
+		if (offset == count)
+			goto found;
+		else if (offset < count)
+			break;
+		offset -= count;
+	}
+	/* panic? */
+	return -EIO;
+found:
+	for (;;) {
+		start = be16_to_cpu(extent->block);
+		if (count <= block_nr) {
+			hfs_clear_vbm_bits(sb, start, count);
+			extent->block = 0;
+			extent->count = 0;
+			block_nr -= count;
+		} else {
+			count -= block_nr;
+			hfs_clear_vbm_bits(sb, start + count, block_nr);
+			extent->count = cpu_to_be16(count);
+			block_nr = 0;
+		}
+		if (!block_nr || !i)
+			return 0;
+		i--;
+		extent--;
+		count = be16_to_cpu(extent->count);
+	}
+}
+
+int hfs_free_fork(struct super_block *sb, struct hfs_cat_file *file, int type)
+{
+	struct hfs_find_data fd;
+	u32 total_blocks, blocks, start;
+	u32 cnid = be32_to_cpu(file->FlNum);
+	struct hfs_extent *extent;
+	int res, i;
+
+	if (type == HFS_FK_DATA) {
+		total_blocks = be32_to_cpu(file->PyLen);
+		extent = file->ExtRec;
+	} else {
+		total_blocks = be32_to_cpu(file->RPyLen);
+		extent = file->RExtRec;
+	}
+	total_blocks /= HFS_SB(sb)->alloc_blksz;
+	if (!total_blocks)
+		return 0;
+
+	blocks = 0;
+	for (i = 0; i < 3; i++)
+		blocks += be16_to_cpu(extent[i].count);
+
+	res = hfs_free_extents(sb, extent, blocks, blocks);
+	if (res)
+		return res;
+	if (total_blocks == blocks)
+		return 0;
+
+	res = hfs_find_init(HFS_SB(sb)->ext_tree, &fd);
+	if (res)
+		return res;
+	do {
+		res = __hfs_ext_read_extent(&fd, extent, cnid, total_blocks, type);
+		if (res)
+			break;
+		start = be16_to_cpu(fd.key->ext.FABN);
+		hfs_free_extents(sb, extent, total_blocks - start, total_blocks);
+		hfs_brec_remove(&fd);
+		total_blocks = start;
+	} while (total_blocks > blocks);
+	hfs_find_exit(&fd);
+
+	return res;
+}
+
+/*
+ * hfs_get_block
+ */
+int hfs_get_block(struct inode *inode, sector_t block,
+		  struct buffer_head *bh_result, int create)
+{
+	struct super_block *sb;
+	u16 dblock, ablock;
+	int res;
+
+	sb = inode->i_sb;
+	/* Convert inode block to disk allocation block */
+	ablock = (u32)block / HFS_SB(sb)->fs_div;
+
+	if (block >= HFS_I(inode)->fs_blocks) {
+		if (!create)
+			return 0;
+		if (block > HFS_I(inode)->fs_blocks)
+			return -EIO;
+		if (ablock >= HFS_I(inode)->alloc_blocks) {
+			res = hfs_extend_file(inode);
+			if (res)
+				return res;
+		}
+	} else
+		create = 0;
+
+	if (ablock < HFS_I(inode)->first_blocks) {
+		dblock = hfs_ext_find_block(HFS_I(inode)->first_extents, ablock);
+		goto done;
+	}
+
+	mutex_lock(&HFS_I(inode)->extents_lock);
+	res = hfs_ext_read_extent(inode, ablock);
+	if (!res)
+		dblock = hfs_ext_find_block(HFS_I(inode)->cached_extents,
+					    ablock - HFS_I(inode)->cached_start);
+	else {
+		mutex_unlock(&HFS_I(inode)->extents_lock);
+		return -EIO;
+	}
+	mutex_unlock(&HFS_I(inode)->extents_lock);
+
+done:
+	map_bh(bh_result, sb, HFS_SB(sb)->fs_start +
+	       dblock * HFS_SB(sb)->fs_div +
+	       (u32)block % HFS_SB(sb)->fs_div);
+
+	if (create) {
+		set_buffer_new(bh_result);
+		HFS_I(inode)->phys_size += sb->s_blocksize;
+		HFS_I(inode)->fs_blocks++;
+		inode_add_bytes(inode, sb->s_blocksize);
+		mark_inode_dirty(inode);
+	}
+	return 0;
+}
+
+int hfs_extend_file(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	u32 start, len, goal;
+	int res;
+
+	mutex_lock(&HFS_I(inode)->extents_lock);
+	if (HFS_I(inode)->alloc_blocks == HFS_I(inode)->first_blocks)
+		goal = hfs_ext_lastblock(HFS_I(inode)->first_extents);
+	else {
+		res = hfs_ext_read_extent(inode, HFS_I(inode)->alloc_blocks);
+		if (res)
+			goto out;
+		goal = hfs_ext_lastblock(HFS_I(inode)->cached_extents);
+	}
+
+	len = HFS_I(inode)->clump_blocks;
+	start = hfs_vbm_search_free(sb, goal, &len);
+	if (!len) {
+		res = -ENOSPC;
+		goto out;
+	}
+
+	hfs_dbg("ino %llu, start %u, len %u\n", inode->i_ino, start, len);
+	if (HFS_I(inode)->alloc_blocks == HFS_I(inode)->first_blocks) {
+		if (!HFS_I(inode)->first_blocks) {
+			hfs_dbg("first_extent: start %u, len %u\n",
+				start, len);
+			/* no extents yet */
+			HFS_I(inode)->first_extents[0].block = cpu_to_be16(start);
+			HFS_I(inode)->first_extents[0].count = cpu_to_be16(len);
+			res = 0;
+		} else {
+			/* try to append to extents in inode */
+			res = hfs_add_extent(HFS_I(inode)->first_extents,
+					     HFS_I(inode)->alloc_blocks,
+					     start, len);
+			if (res == -ENOSPC)
+				goto insert_extent;
+		}
+		if (!res) {
+			hfs_dump_extent(HFS_I(inode)->first_extents);
+			HFS_I(inode)->first_blocks += len;
+		}
+	} else {
+		res = hfs_add_extent(HFS_I(inode)->cached_extents,
+				     HFS_I(inode)->alloc_blocks -
+				     HFS_I(inode)->cached_start,
+				     start, len);
+		if (!res) {
+			hfs_dump_extent(HFS_I(inode)->cached_extents);
+			HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY;
+			HFS_I(inode)->cached_blocks += len;
+		} else if (res == -ENOSPC)
+			goto insert_extent;
+	}
+out:
+	mutex_unlock(&HFS_I(inode)->extents_lock);
+	if (!res) {
+		HFS_I(inode)->alloc_blocks += len;
+		mark_inode_dirty(inode);
+		if (inode->i_ino < HFS_FIRSTUSER_CNID)
+			set_bit(HFS_FLG_ALT_MDB_DIRTY, &HFS_SB(sb)->flags);
+		set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
+		hfs_mark_mdb_dirty(sb);
+	}
+	return res;
+
+insert_extent:
+	hfs_dbg("insert new extent\n");
+	res = hfs_ext_write_extent(inode);
+	if (res)
+		goto out;
+
+	memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
+	HFS_I(inode)->cached_extents[0].block = cpu_to_be16(start);
+	HFS_I(inode)->cached_extents[0].count = cpu_to_be16(len);
+	hfs_dump_extent(HFS_I(inode)->cached_extents);
+	HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW;
+	HFS_I(inode)->cached_start = HFS_I(inode)->alloc_blocks;
+	HFS_I(inode)->cached_blocks = len;
+
+	res = 0;
+	goto out;
+}
+
+void hfs_file_truncate(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct hfs_find_data fd;
+	u16 blk_cnt, alloc_cnt, start;
+	u32 size;
+	int res;
+
+	hfs_dbg("ino %llu, phys_size %llu -> i_size %llu\n",
+		inode->i_ino, (long long)HFS_I(inode)->phys_size,
+		inode->i_size);
+	if (inode->i_size > HFS_I(inode)->phys_size) {
+		struct address_space *mapping = inode->i_mapping;
+		void *fsdata = NULL;
+		struct folio *folio;
+
+		/* XXX: Can use generic_cont_expand? */
+		size = inode->i_size - 1;
+		res = hfs_write_begin(NULL, mapping, size + 1, 0, &folio,
+				&fsdata);
+		if (!res) {
+			res = generic_write_end(NULL, mapping, size + 1, 0, 0,
+					folio, fsdata);
+		}
+		if (res)
+			inode->i_size = HFS_I(inode)->phys_size;
+		return;
+	} else if (inode->i_size == HFS_I(inode)->phys_size)
+		return;
+	size = inode->i_size + HFS_SB(sb)->alloc_blksz - 1;
+	blk_cnt = size / HFS_SB(sb)->alloc_blksz;
+	alloc_cnt = HFS_I(inode)->alloc_blocks;
+	if (blk_cnt == alloc_cnt)
+		goto out;
+
+	mutex_lock(&HFS_I(inode)->extents_lock);
+	res = hfs_find_init(HFS_SB(sb)->ext_tree, &fd);
+	if (res) {
+		mutex_unlock(&HFS_I(inode)->extents_lock);
+		/* XXX: We lack error handling of hfs_file_truncate() */
+		return;
+	}
+	while (1) {
+		if (alloc_cnt == HFS_I(inode)->first_blocks) {
+			hfs_free_extents(sb, HFS_I(inode)->first_extents,
+					 alloc_cnt, alloc_cnt - blk_cnt);
+			hfs_dump_extent(HFS_I(inode)->first_extents);
+			HFS_I(inode)->first_blocks = blk_cnt;
+			break;
+		}
+		res = __hfs_ext_cache_extent(&fd, inode, alloc_cnt);
+		if (res)
+			break;
+		start = HFS_I(inode)->cached_start;
+		hfs_free_extents(sb, HFS_I(inode)->cached_extents,
+				 alloc_cnt - start, alloc_cnt - blk_cnt);
+		hfs_dump_extent(HFS_I(inode)->cached_extents);
+		if (blk_cnt > start) {
+			HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY;
+			break;
+		}
+		alloc_cnt = start;
+		HFS_I(inode)->cached_start = HFS_I(inode)->cached_blocks = 0;
+		HFS_I(inode)->flags &= ~(HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW);
+		hfs_brec_remove(&fd);
+	}
+	hfs_find_exit(&fd);
+	mutex_unlock(&HFS_I(inode)->extents_lock);
+
+	HFS_I(inode)->alloc_blocks = blk_cnt;
+out:
+	HFS_I(inode)->phys_size = inode->i_size;
+	HFS_I(inode)->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+	inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
+	mark_inode_dirty(inode);
+}
diff --git a/fs/hfs/hfs.h b/fs/hfs/hfs.h
new file mode 100644
index 000000000..2e958c46b
--- /dev/null
+++ b/fs/hfs/hfs.h
@@ -0,0 +1,21 @@
+/*
+ *  linux/fs/hfs/hfs.h
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ */
+
+#ifndef _HFS_H
+#define _HFS_H
+
+#include <linux/hfs_common.h>
+
+/*======== Data structures kept in memory ========*/
+
+struct hfs_readdir_data {
+	loff_t pos;
+	struct hfs_cat_key key;
+};
+
+#endif
diff --git a/fs/hfs/hfs_fs.h b/fs/hfs/hfs_fs.h
new file mode 100644
index 000000000..e250f87a5
--- /dev/null
+++ b/fs/hfs/hfs_fs.h
@@ -0,0 +1,319 @@
+/*
+ *  linux/fs/hfs/hfs_fs.h
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ */
+
+#ifndef _LINUX_HFS_FS_H
+#define _LINUX_HFS_FS_H
+
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/mutex.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/workqueue.h>
+
+#include <asm/byteorder.h>
+#include <linux/uaccess.h>
+
+#include "hfs.h"
+
+/*
+ * struct hfs_inode_info
+ *
+ * The HFS-specific part of a Linux (struct inode)
+ */
+struct hfs_inode_info {
+	atomic_t opencnt;
+
+	unsigned int flags;
+
+	/* to deal with localtime ugliness */
+	int tz_secondswest;
+
+	struct hfs_cat_key cat_key;
+
+	struct inode *rsrc_inode;
+
+	struct mutex extents_lock;
+
+	u16 alloc_blocks, clump_blocks;
+	sector_t fs_blocks;
+	/* Allocation extents from catlog record or volume header */
+	hfs_extent_rec first_extents;
+	u16 first_blocks;
+	hfs_extent_rec cached_extents;
+	u16 cached_start, cached_blocks;
+
+	loff_t phys_size;
+	struct inode vfs_inode;
+};
+
+#define HFS_FLG_RSRC		0x0001
+#define HFS_FLG_EXT_DIRTY	0x0002
+#define HFS_FLG_EXT_NEW		0x0004
+
+#define HFS_IS_RSRC(inode)	(HFS_I(inode)->flags & HFS_FLG_RSRC)
+
+/*
+ * struct hfs_sb_info
+ *
+ * The HFS-specific part of a Linux (struct super_block)
+ */
+struct hfs_sb_info {
+	struct mutex mdb_lock;			/* MDB operations lock */
+	struct buffer_head *mdb_bh;		/* The hfs_buffer
+						   holding the real
+						   superblock (aka VIB
+						   or MDB) */
+	unsigned int mdb_offset;		/* byte offset of the MDB
+						   sector within mdb_bh's
+						   data */
+	struct hfs_mdb *mdb;			/* in-memory copy of the MDB */
+	struct buffer_head *alt_mdb_bh;		/* The hfs_buffer holding
+						   the alternate superblock */
+	unsigned int alt_mdb_offset;		/* byte offset of the alternate
+						   MDB sector within
+						   alt_mdb_bh's data */
+	struct hfs_mdb *alt_mdb;		/* in-memory copy of the
+						   alternate MDB */
+	__be32 *bitmap;				/* The page holding the
+						   allocation bitmap */
+	struct hfs_btree *ext_tree;			/* Information about
+						   the extents b-tree */
+	struct hfs_btree *cat_tree;			/* Information about
+						   the catalog b-tree */
+	atomic64_t file_count;			/* The number of
+						   regular files in
+						   the filesystem */
+	atomic64_t folder_count;		/* The number of
+						   directories in the
+						   filesystem */
+	atomic64_t next_id;			/* The next available
+						   file id number */
+	u32 clumpablks;				/* The number of allocation
+						   blocks to try to add when
+						   extending a file */
+	u32 fs_start;				/* The first 512-byte
+						   block represented
+						   in the bitmap */
+	u32 part_start;
+	u16 root_files;				/* The number of
+						   regular
+						   (non-directory)
+						   files in the root
+						   directory */
+	u16 root_dirs;				/* The number of
+						   directories in the
+						   root directory */
+	u16 fs_ablocks;				/* The number of
+						   allocation blocks
+						   in the filesystem */
+	u16 free_ablocks;			/* the number of unused
+						   allocation blocks
+						   in the filesystem */
+	u32 alloc_blksz;			/* The size of an
+						   "allocation block" */
+	int s_quiet;				/* Silent failure when
+						   changing owner or mode? */
+	__be32 s_type;				/* Type for new files */
+	__be32 s_creator;			/* Creator for new files */
+	umode_t s_file_umask;			/* The umask applied to the
+						   permissions on all files */
+	umode_t s_dir_umask;			/* The umask applied to the
+						   permissions on all dirs */
+	kuid_t s_uid;				/* The uid of all files */
+	kgid_t s_gid;				/* The gid of all files */
+
+	int session, part;
+	struct nls_table *nls_io, *nls_disk;
+	struct mutex bitmap_lock;
+	unsigned long flags;
+	u16 blockoffset;
+	int fs_div;
+	struct super_block *sb;
+	int work_queued;		/* non-zero delayed work is queued */
+	struct delayed_work mdb_work;	/* MDB flush delayed work */
+	spinlock_t work_lock;		/* protects mdb_work and work_queued */
+};
+
+#define HFS_FLG_BITMAP_DIRTY	0
+#define HFS_FLG_MDB_DIRTY	1
+#define HFS_FLG_ALT_MDB_DIRTY	2
+
+/* bitmap.c */
+extern u32 hfs_vbm_search_free(struct super_block *sb, u32 goal, u32 *num_bits);
+extern int hfs_clear_vbm_bits(struct super_block *sb, u16 start, u16 count);
+
+/* catalog.c */
+extern int hfs_cat_keycmp(const btree_key *key1, const btree_key *key2);
+struct hfs_find_data;
+extern int hfs_cat_find_brec(struct super_block *sb, u32 cnid,
+			     struct hfs_find_data *fd);
+extern int hfs_cat_create(u32 cnid, struct inode *dir,
+			  const struct qstr *str, struct inode *inode);
+extern int hfs_cat_delete(u32 cnid, struct inode *dir, const struct qstr *str);
+extern int hfs_cat_move(u32 cnid, struct inode *src_dir,
+			const struct qstr *src_name,
+			struct inode *dst_dir,
+			const struct qstr *dst_name);
+extern void hfs_cat_build_key(struct super_block *sb, btree_key *key,
+			      u32 parent, const struct qstr *name);
+
+/*
+ * Validate the CNID of a catalog record.
+ */
+static inline bool hfs_is_valid_cnid(u32 cnid, u8 type)
+{
+	if (likely(cnid >= HFS_FIRSTUSER_CNID))
+		return true;
+
+	switch (cnid) {
+	case HFS_ROOT_CNID:
+		return type == HFS_CDR_DIR;
+	case HFS_EXT_CNID:
+	case HFS_CAT_CNID:
+		return type == HFS_CDR_FIL;
+	default:
+		return false;
+	}
+}
+
+/* dir.c */
+extern const struct file_operations hfs_dir_operations;
+extern const struct inode_operations hfs_dir_inode_operations;
+
+/* extent.c */
+extern int hfs_ext_keycmp(const btree_key *key1, const btree_key *key2);
+extern u16 hfs_ext_find_block(struct hfs_extent *ext, u16 off);
+extern int hfs_free_fork(struct super_block *sb,
+			 struct hfs_cat_file *file, int type);
+extern int hfs_ext_write_extent(struct inode *inode);
+extern int hfs_extend_file(struct inode *inode);
+extern void hfs_file_truncate(struct inode *inode);
+
+extern int hfs_get_block(struct inode *inode, sector_t block,
+			 struct buffer_head *bh_result, int create);
+
+/* inode.c */
+extern const struct address_space_operations hfs_aops;
+extern const struct address_space_operations hfs_btree_aops;
+
+struct file_kattr;
+int hfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
+int hfs_write_begin(const struct kiocb *iocb, struct address_space *mapping,
+		    loff_t pos, unsigned int len, struct folio **foliop,
+		    void **fsdata);
+extern struct inode *hfs_new_inode(struct inode *dir, const struct qstr *name,
+				   umode_t mode);
+extern void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
+				 __be32 *log_size, __be32 *phys_size);
+extern int hfs_write_inode(struct inode *inode, struct writeback_control *wbc);
+extern int hfs_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+			     struct iattr *attr);
+extern void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
+				__be32 __log_size, __be32 phys_size,
+				u32 clump_size);
+extern struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key,
+				hfs_cat_rec *rec);
+extern void hfs_evict_inode(struct inode *inode);
+extern void hfs_delete_inode(struct inode *inode);
+
+/* attr.c */
+extern const struct xattr_handler * const hfs_xattr_handlers[];
+
+/* mdb.c */
+extern bool is_hfs_cnid_counts_valid(struct super_block *sb);
+extern int hfs_mdb_get(struct super_block *sb);
+extern int hfs_mdb_commit(struct super_block *sb);
+extern void hfs_mdb_close(struct super_block *sb);
+extern void hfs_mdb_put(struct super_block *sb);
+
+/* part_tbl.c */
+extern int hfs_part_find(struct super_block *sb,
+			 sector_t *part_start, sector_t *part_size);
+
+/* string.c */
+extern const struct dentry_operations hfs_dentry_operations;
+
+extern int hfs_hash_dentry(const struct dentry *dentry, struct qstr *this);
+extern int hfs_strcmp(const unsigned char *s1, unsigned int len1,
+		      const unsigned char *s2, unsigned int len2);
+extern int hfs_compare_dentry(const struct dentry *dentry,
+				unsigned int len, const char *str,
+				const struct qstr *name);
+
+/* trans.c */
+extern void hfs_asc2mac(struct super_block *sb,
+			struct hfs_name *out, const struct qstr *in);
+extern int hfs_mac2asc(struct super_block *sb,
+			char *out, const struct hfs_name *in);
+
+/* super.c */
+extern void hfs_mark_mdb_dirty(struct super_block *sb);
+
+/*
+ * There are two time systems.  Both are based on seconds since
+ * a particular time/date.
+ *	Unix:	signed little-endian since 00:00 GMT, Jan. 1, 1970
+ *	mac:	unsigned big-endian since 00:00 GMT, Jan. 1, 1904
+ *
+ * HFS implementations are highly inconsistent, this one matches the
+ * traditional behavior of 64-bit Linux, giving the most useful
+ * time range between 1970 and 2106, by treating any on-disk timestamp
+ * under HFS_UTC_OFFSET (Jan 1 1970) as a time between 2040 and 2106.
+ */
+#define HFS_UTC_OFFSET 2082844800U
+
+static inline time64_t __hfs_m_to_utime(__be32 mt)
+{
+	time64_t ut = (u32)(be32_to_cpu(mt) - HFS_UTC_OFFSET);
+
+	return ut + sys_tz.tz_minuteswest * 60;
+}
+
+static inline __be32 __hfs_u_to_mtime(time64_t ut)
+{
+	ut -= sys_tz.tz_minuteswest * 60;
+
+	return cpu_to_be32(lower_32_bits(ut) + HFS_UTC_OFFSET);
+}
+#define HFS_I(inode)	(container_of(inode, struct hfs_inode_info, vfs_inode))
+#define HFS_SB(sb)	((struct hfs_sb_info *)(sb)->s_fs_info)
+
+#define hfs_m_to_utime(time)   (struct timespec64){ .tv_sec = __hfs_m_to_utime(time) }
+#define hfs_u_to_mtime(time)   __hfs_u_to_mtime((time).tv_sec)
+#define hfs_mtime()		__hfs_u_to_mtime(ktime_get_real_seconds())
+
+static inline const char *hfs_mdb_name(struct super_block *sb)
+{
+	return sb->s_id;
+}
+
+static inline void hfs_bitmap_dirty(struct super_block *sb)
+{
+	set_bit(HFS_FLG_BITMAP_DIRTY, &HFS_SB(sb)->flags);
+	hfs_mark_mdb_dirty(sb);
+}
+
+#define sb_bread512(sb, sec, data) ({			\
+	struct buffer_head *__bh;			\
+	sector_t __block;				\
+	loff_t __start;					\
+	int __offset;					\
+							\
+	__start = (loff_t)(sec) << HFS_SECTOR_SIZE_BITS;\
+	__block = __start >> (sb)->s_blocksize_bits;	\
+	__offset = __start & ((sb)->s_blocksize - 1);	\
+	__bh = sb_bread((sb), __block);			\
+	if (likely(__bh != NULL))			\
+		data = (void *)(__bh->b_data + __offset);\
+	else						\
+		data = NULL;				\
+	__bh;						\
+})
+
+#endif
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
new file mode 100644
index 000000000..2aef3c36a
--- /dev/null
+++ b/fs/hfs/inode.c
@@ -0,0 +1,752 @@
+/*
+ *  linux/fs/hfs/inode.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains inode-related functions which do not depend on
+ * which scheme is being used to represent forks.
+ *
+ * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
+ */
+
+#include <linux/pagemap.h>
+#include <linux/mpage.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/uio.h>
+#include <linux/xattr.h>
+#include <linux/blkdev.h>
+#include <linux/fileattr.h>
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+static const struct file_operations hfs_file_operations;
+static const struct inode_operations hfs_file_inode_operations;
+
+/*================ Variable-like macros ================*/
+
+#define HFS_VALID_MODE_BITS  (S_IFREG | S_IFDIR | S_IRWXUGO)
+
+static int hfs_read_folio(struct file *file, struct folio *folio)
+{
+	return block_read_full_folio(folio, hfs_get_block);
+}
+
+static void hfs_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);
+		hfs_file_truncate(inode);
+	}
+}
+
+int hfs_write_begin(const struct kiocb *iocb, struct address_space *mapping,
+		    loff_t pos, unsigned int len, struct folio **foliop,
+		    void **fsdata)
+{
+	struct inode *inode = mapping->host;
+	struct hfs_sb_info *sbi = HFS_SB(inode->i_sb);
+	loff_t total_capacity;
+	int ret;
+
+	total_capacity = (loff_t)sbi->fs_ablocks * sbi->alloc_blksz;
+
+	if (pos >= total_capacity)
+		return -EFBIG;
+
+	ret = cont_write_begin(iocb, mapping, pos, len, foliop, fsdata,
+				hfs_get_block,
+				&HFS_I(inode)->phys_size);
+	if (unlikely(ret))
+		hfs_write_failed(mapping, pos + len);
+
+	return ret;
+}
+
+static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
+{
+	return generic_block_bmap(mapping, block, hfs_get_block);
+}
+
+static bool hfs_release_folio(struct folio *folio, gfp_t mask)
+{
+	struct inode *inode = folio->mapping->host;
+	struct super_block *sb = inode->i_sb;
+	struct hfs_btree *tree;
+	struct hfs_bnode *node;
+	u32 nidx;
+	int i;
+	bool res = true;
+
+	switch (inode->i_ino) {
+	case HFS_EXT_CNID:
+		tree = HFS_SB(sb)->ext_tree;
+		break;
+	case HFS_CAT_CNID:
+		tree = HFS_SB(sb)->cat_tree;
+		break;
+	default:
+		BUG();
+		return false;
+	}
+
+	if (!tree)
+		return false;
+
+	if (tree->node_size >= PAGE_SIZE) {
+		nidx = folio->index >> (tree->node_size_shift - PAGE_SHIFT);
+		spin_lock(&tree->hash_lock);
+		node = hfs_bnode_findhash(tree, nidx);
+		if (!node)
+			;
+		else if (atomic_read(&node->refcnt))
+			res = false;
+		if (res && node) {
+			hfs_bnode_unhash(node);
+			hfs_bnode_free(node);
+		}
+		spin_unlock(&tree->hash_lock);
+	} else {
+		nidx = folio->index << (PAGE_SHIFT - tree->node_size_shift);
+		i = 1 << (PAGE_SHIFT - tree->node_size_shift);
+		spin_lock(&tree->hash_lock);
+		do {
+			node = hfs_bnode_findhash(tree, nidx++);
+			if (!node)
+				continue;
+			if (atomic_read(&node->refcnt)) {
+				res = false;
+				break;
+			}
+			hfs_bnode_unhash(node);
+			hfs_bnode_free(node);
+		} while (--i && nidx < tree->node_count);
+		spin_unlock(&tree->hash_lock);
+	}
+	return res ? try_to_free_buffers(folio) : false;
+}
+
+static ssize_t hfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	size_t count = iov_iter_count(iter);
+	ssize_t ret;
+
+	ret = blockdev_direct_IO(iocb, inode, iter, hfs_get_block);
+
+	/*
+	 * In case of error extending write may have instantiated a few
+	 * blocks outside i_size. Trim these off again.
+	 */
+	if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
+		loff_t isize = i_size_read(inode);
+		loff_t end = iocb->ki_pos + count;
+
+		if (end > isize)
+			hfs_write_failed(mapping, end);
+	}
+
+	return ret;
+}
+
+static int hfs_writepages(struct address_space *mapping,
+			  struct writeback_control *wbc)
+{
+	return mpage_writepages(mapping, wbc, hfs_get_block);
+}
+
+const struct address_space_operations hfs_btree_aops = {
+	.dirty_folio	= block_dirty_folio,
+	.invalidate_folio = block_invalidate_folio,
+	.read_folio	= hfs_read_folio,
+	.writepages	= hfs_writepages,
+	.write_begin	= hfs_write_begin,
+	.write_end	= generic_write_end,
+	.migrate_folio	= buffer_migrate_folio,
+	.bmap		= hfs_bmap,
+	.release_folio	= hfs_release_folio,
+};
+
+const struct address_space_operations hfs_aops = {
+	.dirty_folio	= block_dirty_folio,
+	.invalidate_folio = block_invalidate_folio,
+	.read_folio	= hfs_read_folio,
+	.write_begin	= hfs_write_begin,
+	.write_end	= generic_write_end,
+	.bmap		= hfs_bmap,
+	.direct_IO	= hfs_direct_IO,
+	.writepages	= hfs_writepages,
+	.migrate_folio	= buffer_migrate_folio,
+};
+
+/*
+ * hfs_new_inode
+ */
+struct inode *hfs_new_inode(struct inode *dir, const struct qstr *name, umode_t mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode = new_inode(sb);
+	s64 next_id;
+	s64 file_count;
+	s64 folder_count;
+	int err = -ENOMEM;
+
+	if (!inode)
+		goto out_err;
+
+	err = -ERANGE;
+
+	mutex_init(&HFS_I(inode)->extents_lock);
+	hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
+	next_id = atomic64_inc_return(&HFS_SB(sb)->next_id);
+	if (next_id > U32_MAX) {
+		atomic64_dec(&HFS_SB(sb)->next_id);
+		pr_err("cannot create new inode: next CNID exceeds limit\n");
+		goto out_discard;
+	}
+	inode->i_ino = (u32)next_id - 1;
+	inode->i_mode = mode;
+	inode->i_uid = current_fsuid();
+	inode->i_gid = current_fsgid();
+	set_nlink(inode, 1);
+	simple_inode_init_ts(inode);
+	HFS_I(inode)->flags = 0;
+	HFS_I(inode)->rsrc_inode = NULL;
+	HFS_I(inode)->fs_blocks = 0;
+	HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
+	if (S_ISDIR(mode)) {
+		inode->i_size = 2;
+		folder_count = atomic64_inc_return(&HFS_SB(sb)->folder_count);
+		if (folder_count> U32_MAX) {
+			atomic64_dec(&HFS_SB(sb)->folder_count);
+			pr_err("cannot create new inode: folder count exceeds limit\n");
+			goto out_discard;
+		}
+		if (dir->i_ino == HFS_ROOT_CNID)
+			HFS_SB(sb)->root_dirs++;
+		inode->i_op = &hfs_dir_inode_operations;
+		inode->i_fop = &hfs_dir_operations;
+		inode->i_mode |= S_IRWXUGO;
+		inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
+	} else if (S_ISREG(mode)) {
+		HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
+		file_count = atomic64_inc_return(&HFS_SB(sb)->file_count);
+		if (file_count > U32_MAX) {
+			atomic64_dec(&HFS_SB(sb)->file_count);
+			pr_err("cannot create new inode: file count exceeds limit\n");
+			goto out_discard;
+		}
+		if (dir->i_ino == HFS_ROOT_CNID)
+			HFS_SB(sb)->root_files++;
+		inode->i_op = &hfs_file_inode_operations;
+		inode->i_fop = &hfs_file_operations;
+		inode->i_mapping->a_ops = &hfs_aops;
+		inode->i_mode |= S_IRUGO|S_IXUGO;
+		if (mode & S_IWUSR)
+			inode->i_mode |= S_IWUGO;
+		inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
+		HFS_I(inode)->phys_size = 0;
+		HFS_I(inode)->alloc_blocks = 0;
+		HFS_I(inode)->first_blocks = 0;
+		HFS_I(inode)->cached_start = 0;
+		HFS_I(inode)->cached_blocks = 0;
+		memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
+		memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
+	}
+	insert_inode_hash(inode);
+	mark_inode_dirty(inode);
+	set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
+	hfs_mark_mdb_dirty(sb);
+
+	return inode;
+
+	out_discard:
+		iput(inode);
+	out_err:
+		return ERR_PTR(err);
+}
+
+void hfs_delete_inode(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+
+	hfs_dbg("ino %llu\n", inode->i_ino);
+	if (S_ISDIR(inode->i_mode)) {
+		atomic64_dec(&HFS_SB(sb)->folder_count);
+		if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
+			HFS_SB(sb)->root_dirs--;
+		set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
+		hfs_mark_mdb_dirty(sb);
+		return;
+	}
+
+	atomic64_dec(&HFS_SB(sb)->file_count);
+	if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
+		HFS_SB(sb)->root_files--;
+	if (S_ISREG(inode->i_mode)) {
+		if (!inode->i_nlink) {
+			inode->i_size = 0;
+			hfs_file_truncate(inode);
+		}
+	}
+	set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
+	hfs_mark_mdb_dirty(sb);
+}
+
+void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
+			 __be32 __log_size, __be32 phys_size, u32 clump_size)
+{
+	struct super_block *sb = inode->i_sb;
+	u32 log_size = be32_to_cpu(__log_size);
+	u16 count;
+	int i;
+
+	memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
+	for (count = 0, i = 0; i < 3; i++)
+		count += be16_to_cpu(ext[i].count);
+	HFS_I(inode)->first_blocks = count;
+	HFS_I(inode)->cached_start = 0;
+	HFS_I(inode)->cached_blocks = 0;
+
+	inode->i_size = HFS_I(inode)->phys_size = log_size;
+	HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+	inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
+	HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
+				     HFS_SB(sb)->alloc_blksz;
+	HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
+	if (!HFS_I(inode)->clump_blocks)
+		HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
+}
+
+struct hfs_iget_data {
+	struct hfs_cat_key *key;
+	hfs_cat_rec *rec;
+};
+
+static int hfs_test_inode(struct inode *inode, void *data)
+{
+	struct hfs_iget_data *idata = data;
+	hfs_cat_rec *rec;
+
+	rec = idata->rec;
+	switch (rec->type) {
+	case HFS_CDR_DIR:
+		return inode->i_ino == be32_to_cpu(rec->dir.DirID);
+	case HFS_CDR_FIL:
+		return inode->i_ino == be32_to_cpu(rec->file.FlNum);
+	default:
+		BUG();
+		return 1;
+	}
+}
+
+/*
+ * hfs_read_inode
+ */
+static int hfs_read_inode(struct inode *inode, void *data)
+{
+	struct hfs_iget_data *idata = data;
+	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
+	hfs_cat_rec *rec;
+	struct timespec64 mtime;
+
+	HFS_I(inode)->flags = 0;
+	HFS_I(inode)->rsrc_inode = NULL;
+	mutex_init(&HFS_I(inode)->extents_lock);
+
+	/* Initialize the inode */
+	inode->i_uid = hsb->s_uid;
+	inode->i_gid = hsb->s_gid;
+	set_nlink(inode, 1);
+
+	if (idata->key)
+		HFS_I(inode)->cat_key = *idata->key;
+	else
+		HFS_I(inode)->flags |= HFS_FLG_RSRC;
+	HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
+
+	rec = idata->rec;
+	switch (rec->type) {
+	case HFS_CDR_FIL:
+		if (!hfs_is_valid_cnid(be32_to_cpu(rec->file.FlNum), rec->type))
+			return -EIO;
+
+		if (!HFS_IS_RSRC(inode)) {
+			hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
+					    rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
+		} else {
+			hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
+					    rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
+		}
+
+		inode->i_ino = be32_to_cpu(rec->file.FlNum);
+		inode->i_mode = S_IRUGO | S_IXUGO;
+		if (!(rec->file.Flags & HFS_FIL_LOCK))
+			inode->i_mode |= S_IWUGO;
+		inode->i_mode &= ~hsb->s_file_umask;
+		inode->i_mode |= S_IFREG;
+		mtime = hfs_m_to_utime(rec->file.MdDat);
+		inode_set_ctime_to_ts(inode, mtime);
+		inode_set_atime_to_ts(inode, mtime);
+		inode_set_mtime_to_ts(inode, mtime);
+		inode->i_op = &hfs_file_inode_operations;
+		inode->i_fop = &hfs_file_operations;
+		inode->i_mapping->a_ops = &hfs_aops;
+		break;
+	case HFS_CDR_DIR:
+		if (!hfs_is_valid_cnid(be32_to_cpu(rec->dir.DirID), rec->type))
+			return -EIO;
+
+		inode->i_ino = be32_to_cpu(rec->dir.DirID);
+		inode->i_size = be16_to_cpu(rec->dir.Val) + 2;
+		HFS_I(inode)->fs_blocks = 0;
+		inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask);
+		mtime = hfs_m_to_utime(rec->dir.MdDat);
+		inode_set_ctime_to_ts(inode, mtime);
+		inode_set_atime_to_ts(inode, mtime);
+		inode_set_mtime_to_ts(inode, mtime);
+		inode->i_op = &hfs_dir_inode_operations;
+		inode->i_fop = &hfs_dir_operations;
+		break;
+	default:
+		make_bad_inode(inode);
+	}
+	return 0;
+}
+
+/*
+ * __hfs_iget()
+ *
+ * Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
+ * the catalog B-tree and the 'type' of the desired file return the
+ * inode for that file/directory or NULL.  Note that 'type' indicates
+ * whether we want the actual file or directory, or the corresponding
+ * metadata (AppleDouble header file or CAP metadata file).
+ */
+struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key, hfs_cat_rec *rec)
+{
+	struct hfs_iget_data data = { key, rec };
+	struct inode *inode;
+	u32 cnid;
+
+	switch (rec->type) {
+	case HFS_CDR_DIR:
+		cnid = be32_to_cpu(rec->dir.DirID);
+		break;
+	case HFS_CDR_FIL:
+		cnid = be32_to_cpu(rec->file.FlNum);
+		break;
+	default:
+		return NULL;
+	}
+	inode = iget5_locked(sb, cnid, hfs_test_inode, hfs_read_inode, &data);
+	if (inode && (inode_state_read_once(inode) & I_NEW))
+		unlock_new_inode(inode);
+	return inode;
+}
+
+void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
+			  __be32 *log_size, __be32 *phys_size)
+{
+	memcpy(ext, HFS_I(inode)->first_extents, sizeof(hfs_extent_rec));
+
+	if (log_size)
+		*log_size = cpu_to_be32(inode->i_size);
+	if (phys_size)
+		*phys_size = cpu_to_be32(HFS_I(inode)->alloc_blocks *
+					 HFS_SB(inode->i_sb)->alloc_blksz);
+}
+
+int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+	struct inode *main_inode = inode;
+	struct hfs_find_data fd;
+	hfs_cat_rec rec;
+	int res;
+
+	hfs_dbg("ino %llu\n", inode->i_ino);
+	res = hfs_ext_write_extent(inode);
+	if (res)
+		return res;
+
+	if (inode->i_ino < HFS_FIRSTUSER_CNID) {
+		switch (inode->i_ino) {
+		case HFS_ROOT_CNID:
+			break;
+		case HFS_EXT_CNID:
+			hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
+			return 0;
+		case HFS_CAT_CNID:
+			hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree);
+			return 0;
+		default:
+			BUG();
+			return -EIO;
+		}
+	}
+
+	if (HFS_IS_RSRC(inode))
+		main_inode = HFS_I(inode)->rsrc_inode;
+
+	if (!main_inode->i_nlink)
+		return 0;
+
+	if (hfs_find_init(HFS_SB(main_inode->i_sb)->cat_tree, &fd))
+		/* panic? */
+		return -EIO;
+
+	res = -EIO;
+	if (HFS_I(main_inode)->cat_key.CName.len > HFS_NAMELEN)
+		goto out;
+	fd.search_key->cat = HFS_I(main_inode)->cat_key;
+	if (hfs_brec_find(&fd))
+		goto out;
+
+	if (S_ISDIR(main_inode->i_mode)) {
+		if (fd.entrylength < sizeof(struct hfs_cat_dir))
+			goto out;
+		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
+			   sizeof(struct hfs_cat_dir));
+		if (rec.type != HFS_CDR_DIR ||
+		    be32_to_cpu(rec.dir.DirID) != inode->i_ino) {
+		}
+
+		rec.dir.MdDat = hfs_u_to_mtime(inode_get_mtime(inode));
+		rec.dir.Val = cpu_to_be16(inode->i_size - 2);
+
+		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
+			    sizeof(struct hfs_cat_dir));
+	} else if (HFS_IS_RSRC(inode)) {
+		if (fd.entrylength < sizeof(struct hfs_cat_file))
+			goto out;
+		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
+			       sizeof(struct hfs_cat_file));
+		hfs_inode_write_fork(inode, rec.file.RExtRec,
+				     &rec.file.RLgLen, &rec.file.RPyLen);
+		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
+				sizeof(struct hfs_cat_file));
+	} else {
+		if (fd.entrylength < sizeof(struct hfs_cat_file))
+			goto out;
+		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
+			   sizeof(struct hfs_cat_file));
+		if (rec.type != HFS_CDR_FIL ||
+		    be32_to_cpu(rec.file.FlNum) != inode->i_ino) {
+		}
+
+		if (inode->i_mode & S_IWUSR)
+			rec.file.Flags &= ~HFS_FIL_LOCK;
+		else
+			rec.file.Flags |= HFS_FIL_LOCK;
+		hfs_inode_write_fork(inode, rec.file.ExtRec, &rec.file.LgLen, &rec.file.PyLen);
+		rec.file.MdDat = hfs_u_to_mtime(inode_get_mtime(inode));
+
+		hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
+			    sizeof(struct hfs_cat_file));
+	}
+	res = 0;
+out:
+	hfs_find_exit(&fd);
+	return res;
+}
+
+static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
+				      unsigned int flags)
+{
+	struct inode *inode = NULL;
+	hfs_cat_rec rec;
+	struct hfs_find_data fd;
+	int res;
+
+	if (HFS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
+		goto out;
+
+	inode = HFS_I(dir)->rsrc_inode;
+	if (inode)
+		goto out;
+
+	inode = new_inode(dir->i_sb);
+	if (!inode)
+		return ERR_PTR(-ENOMEM);
+
+	res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
+	if (res) {
+		iput(inode);
+		return ERR_PTR(res);
+	}
+	fd.search_key->cat = HFS_I(dir)->cat_key;
+	res = hfs_brec_read(&fd, &rec, sizeof(rec));
+	if (!res) {
+		struct hfs_iget_data idata = { NULL, &rec };
+		res = hfs_read_inode(inode, &idata);
+	}
+	hfs_find_exit(&fd);
+	if (res) {
+		iput(inode);
+		return ERR_PTR(res);
+	}
+
+	if (is_bad_inode(inode)) {
+		iput(inode);
+		return ERR_PTR(-EIO);
+	}
+	HFS_I(inode)->rsrc_inode = dir;
+	HFS_I(dir)->rsrc_inode = inode;
+	igrab(dir);
+	inode_fake_hash(inode);
+	mark_inode_dirty(inode);
+	dont_mount(dentry);
+out:
+	return d_splice_alias(inode, dentry);
+}
+
+void hfs_evict_inode(struct inode *inode)
+{
+	truncate_inode_pages_final(&inode->i_data);
+	clear_inode(inode);
+	if (HFS_IS_RSRC(inode) && HFS_I(inode)->rsrc_inode) {
+		HFS_I(HFS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
+		iput(HFS_I(inode)->rsrc_inode);
+	}
+}
+
+static int hfs_file_open(struct inode *inode, struct file *file)
+{
+	if (HFS_IS_RSRC(inode))
+		inode = HFS_I(inode)->rsrc_inode;
+	atomic_inc(&HFS_I(inode)->opencnt);
+	return 0;
+}
+
+static int hfs_file_release(struct inode *inode, struct file *file)
+{
+	//struct super_block *sb = inode->i_sb;
+
+	if (HFS_IS_RSRC(inode))
+		inode = HFS_I(inode)->rsrc_inode;
+	if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
+		inode_lock(inode);
+		hfs_file_truncate(inode);
+		//if (inode->i_flags & S_DEAD) {
+		//	hfs_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
+		//	hfs_delete_inode(inode);
+		//}
+		inode_unlock(inode);
+	}
+	return 0;
+}
+
+int hfs_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+		      struct iattr *attr)
+{
+	struct inode *inode = d_inode(dentry);
+	struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
+	int error;
+
+	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
+	if (error)
+		return error;
+
+	/* no uig/gid changes and limit which mode bits can be set */
+	if (((attr->ia_valid & ATTR_UID) &&
+	     (!uid_eq(attr->ia_uid, hsb->s_uid))) ||
+	    ((attr->ia_valid & ATTR_GID) &&
+	     (!gid_eq(attr->ia_gid, hsb->s_gid))) ||
+	    ((attr->ia_valid & ATTR_MODE) &&
+	     ((S_ISDIR(inode->i_mode) &&
+	       (attr->ia_mode != inode->i_mode)) ||
+	      (attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
+		return hsb->s_quiet ? 0 : error;
+	}
+
+	/* map file permissions to the closest allowable permissions in HFS */
+	if (attr->ia_valid & ATTR_MODE) {
+		/* Only the 'w' bits can ever change and only all together. */
+		if (attr->ia_mode & S_IWUSR)
+			attr->ia_mode = inode->i_mode | S_IWUGO;
+		else
+			attr->ia_mode = inode->i_mode & ~S_IWUGO;
+		attr->ia_mode &= S_ISDIR(inode->i_mode) ? ~hsb->s_dir_umask: ~hsb->s_file_umask;
+	}
+
+	if ((attr->ia_valid & ATTR_SIZE) &&
+	    attr->ia_size != i_size_read(inode)) {
+		inode_dio_wait(inode);
+
+		error = inode_newsize_ok(inode, attr->ia_size);
+		if (error)
+			return error;
+
+		truncate_setsize(inode, attr->ia_size);
+		hfs_file_truncate(inode);
+		inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+	}
+
+	setattr_copy(&nop_mnt_idmap, inode, attr);
+	mark_inode_dirty(inode);
+	return 0;
+}
+
+static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
+			  int datasync)
+{
+	struct inode *inode = filp->f_mapping->host;
+	struct super_block * sb;
+	int ret, err;
+
+	ret = file_write_and_wait_range(filp, start, end);
+	if (ret)
+		return ret;
+	inode_lock(inode);
+
+	/* sync the inode to buffers */
+	ret = write_inode_now(inode, 0);
+
+	/* sync the superblock to buffers */
+	sb = inode->i_sb;
+	flush_delayed_work(&HFS_SB(sb)->mdb_work);
+	/* .. finally sync the buffers to disk */
+	err = sync_blockdev(sb->s_bdev);
+	if (!ret)
+		ret = err;
+	inode_unlock(inode);
+	return ret;
+}
+
+int hfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	/*
+	 * HFS compares filenames using Mac OS Roman case folding, so
+	 * lookup is always case-insensitive. Names are stored on disk
+	 * with case intact; CASENONPRESERVING stays clear.
+	 */
+	fa->fsx_xflags |= FS_XFLAG_CASEFOLD;
+	fa->flags |= FS_CASEFOLD_FL;
+	return 0;
+}
+
+static const struct file_operations hfs_file_operations = {
+	.llseek		= generic_file_llseek,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
+	.mmap_prepare	= generic_file_mmap_prepare,
+	.splice_read	= filemap_splice_read,
+	.splice_write	= iter_file_splice_write,
+	.fsync		= hfs_file_fsync,
+	.open		= hfs_file_open,
+	.release	= hfs_file_release,
+};
+
+static const struct inode_operations hfs_file_inode_operations = {
+	.lookup		= hfs_file_lookup,
+	.setattr	= hfs_inode_setattr,
+	.listxattr	= generic_listxattr,
+	.fileattr_get	= hfs_fileattr_get,
+};
diff --git a/fs/hfs/mdb.c b/fs/hfs/mdb.c
new file mode 100644
index 000000000..277de712f
--- /dev/null
+++ b/fs/hfs/mdb.c
@@ -0,0 +1,462 @@
+/*
+ *  linux/fs/hfs/mdb.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains functions for reading/writing the MDB.
+ */
+
+#include <linux/cdrom.h>
+#include <linux/blkdev.h>
+#include <linux/nls.h>
+#include <linux/slab.h>
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+/*================ File-local data types ================*/
+
+/*
+ * The HFS Master Directory Block (MDB).
+ *
+ * Also known as the Volume Information Block (VIB), this structure is
+ * the HFS equivalent of a superblock.
+ *
+ * Reference: _Inside Macintosh: Files_ pages 2-59 through 2-62
+ *
+ * modified for HFS Extended
+ */
+
+static int hfs_get_last_session(struct super_block *sb,
+				sector_t *start, sector_t *size)
+{
+	struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
+
+	/* default values */
+	*start = 0;
+	*size = bdev_nr_sectors(sb->s_bdev);
+
+	if (HFS_SB(sb)->session >= 0) {
+		struct cdrom_tocentry te;
+	
+		if (!cdi)
+			return -EINVAL;
+
+		te.cdte_track = HFS_SB(sb)->session;
+		te.cdte_format = CDROM_LBA;
+		if (cdrom_read_tocentry(cdi, &te) ||
+		    (te.cdte_ctrl & CDROM_DATA_TRACK) != 4) {
+			pr_err("invalid session number or type of track\n");
+			return -EINVAL;
+		}
+
+		*start = (sector_t)te.cdte_addr.lba << 2;
+	} else if (cdi) {
+		struct cdrom_multisession ms_info;
+
+		ms_info.addr_format = CDROM_LBA;
+		if (cdrom_multisession(cdi, &ms_info) == 0 && ms_info.xa_flag)
+			*start = (sector_t)ms_info.addr.lba << 2;
+	}
+
+	return 0;
+}
+
+bool is_hfs_cnid_counts_valid(struct super_block *sb)
+{
+	struct hfs_sb_info *sbi = HFS_SB(sb);
+	bool corrupted = false;
+
+	if (unlikely(atomic64_read(&sbi->next_id) > U32_MAX)) {
+		pr_warn("next CNID exceeds limit\n");
+		corrupted = true;
+	}
+	if (unlikely(atomic64_read(&sbi->file_count) > U32_MAX)) {
+		pr_warn("file count exceeds limit\n");
+		corrupted = true;
+	}
+	if (unlikely(atomic64_read(&sbi->folder_count) > U32_MAX)) {
+		pr_warn("folder count exceeds limit\n");
+		corrupted = true;
+	}
+
+	return !corrupted;
+}
+
+/*
+ * hfs_sect_offset() - get byte offset within the buffer_head.
+ */
+static unsigned int hfs_sect_offset(struct super_block *sb, sector_t sec)
+{
+	loff_t start = (loff_t)sec << HFS_SECTOR_SIZE_BITS;
+
+	return start & (sb->s_blocksize - 1);
+}
+
+/*
+ * hfs_mdb_publish() - copy the in-memory primary MDB to the on-disk buffer.
+ */
+static void hfs_mdb_publish(struct hfs_sb_info *sbi)
+{
+	lock_buffer(sbi->mdb_bh);
+	memcpy(sbi->mdb_bh->b_data + sbi->mdb_offset, sbi->mdb, HFS_SECTOR_SIZE);
+	mark_buffer_dirty(sbi->mdb_bh);
+	unlock_buffer(sbi->mdb_bh);
+}
+
+/*
+ * hfs_alt_mdb_publish() - copy the in-memory alternate MDB to its buffer.
+ */
+static void hfs_alt_mdb_publish(struct hfs_sb_info *sbi)
+{
+	lock_buffer(sbi->alt_mdb_bh);
+	memcpy(sbi->alt_mdb_bh->b_data + sbi->alt_mdb_offset, sbi->alt_mdb,
+	       HFS_SECTOR_SIZE);
+	mark_buffer_dirty(sbi->alt_mdb_bh);
+	unlock_buffer(sbi->alt_mdb_bh);
+}
+
+/*
+ * hfs_mdb_get()
+ *
+ * Build the in-core MDB for a filesystem, including
+ * the B-trees and the volume bitmap.
+ */
+int hfs_mdb_get(struct super_block *sb)
+{
+	struct buffer_head *bh;
+	struct hfs_mdb *mdb, *alt_mdb;
+	unsigned int block;
+	char *ptr;
+	int off2, len, size, sect;
+	sector_t part_start, part_size;
+	loff_t off;
+	__be16 attrib;
+
+	/* set the device driver to 512-byte blocks */
+	size = sb_min_blocksize(sb, HFS_SECTOR_SIZE);
+	if (!size)
+		return -EINVAL;
+
+	if (hfs_get_last_session(sb, &part_start, &part_size))
+		return -EINVAL;
+	while (1) {
+		/* See if this is an HFS filesystem */
+		bh = sb_bread512(sb, part_start + HFS_MDB_BLK, mdb);
+		if (!bh)
+			return -EIO;
+
+		if (mdb->drSigWord == cpu_to_be16(HFS_SUPER_MAGIC))
+			break;
+		brelse(bh);
+
+		/* check for a partition block
+		 * (should do this only for cdrom/loop though)
+		 */
+		if (hfs_part_find(sb, &part_start, &part_size))
+			return -EIO;
+	}
+
+	HFS_SB(sb)->alloc_blksz = size = be32_to_cpu(mdb->drAlBlkSiz);
+	if (!size || (size & (HFS_SECTOR_SIZE - 1))) {
+		pr_err("bad allocation block size %d\n", size);
+		brelse(bh);
+		return -EIO;
+	}
+
+	size = min(HFS_SB(sb)->alloc_blksz, (u32)PAGE_SIZE);
+	/* size must be a multiple of 512 */
+	while (size & (size - 1))
+		size -= HFS_SECTOR_SIZE;
+	sect = be16_to_cpu(mdb->drAlBlSt) + part_start;
+	/* align block size to first sector */
+	while (sect & ((size - 1) >> HFS_SECTOR_SIZE_BITS))
+		size >>= 1;
+	/* align block size to weird alloc size */
+	while (HFS_SB(sb)->alloc_blksz & (size - 1))
+		size >>= 1;
+	brelse(bh);
+	if (!sb_set_blocksize(sb, size)) {
+		pr_err("unable to set blocksize to %u\n", size);
+		return -EIO;
+	}
+
+	bh = sb_bread512(sb, part_start + HFS_MDB_BLK, mdb);
+	if (!bh)
+		return -EIO;
+	if (mdb->drSigWord != cpu_to_be16(HFS_SUPER_MAGIC)) {
+		brelse(bh);
+		return -EIO;
+	}
+
+	mdb = kmemdup(mdb, HFS_SECTOR_SIZE, GFP_KERNEL);
+	if (!mdb) {
+		brelse(bh);
+		return -ENOMEM;
+	}
+
+	HFS_SB(sb)->mdb_bh = bh;
+	HFS_SB(sb)->mdb_offset = hfs_sect_offset(sb, part_start + HFS_MDB_BLK);
+	HFS_SB(sb)->mdb = mdb;
+
+	/* These parameters are read from the MDB, and never written */
+	HFS_SB(sb)->part_start = part_start;
+	HFS_SB(sb)->fs_ablocks = be16_to_cpu(mdb->drNmAlBlks);
+	HFS_SB(sb)->fs_div = HFS_SB(sb)->alloc_blksz >> sb->s_blocksize_bits;
+	HFS_SB(sb)->clumpablks = be32_to_cpu(mdb->drClpSiz) /
+				 HFS_SB(sb)->alloc_blksz;
+	if (!HFS_SB(sb)->clumpablks)
+		HFS_SB(sb)->clumpablks = 1;
+	HFS_SB(sb)->fs_start = (be16_to_cpu(mdb->drAlBlSt) + part_start) >>
+			       (sb->s_blocksize_bits - HFS_SECTOR_SIZE_BITS);
+
+	/* These parameters are read from and written to the MDB */
+	HFS_SB(sb)->free_ablocks = be16_to_cpu(mdb->drFreeBks);
+	atomic64_set(&HFS_SB(sb)->next_id, be32_to_cpu(mdb->drNxtCNID));
+	HFS_SB(sb)->root_files = be16_to_cpu(mdb->drNmFls);
+	HFS_SB(sb)->root_dirs = be16_to_cpu(mdb->drNmRtDirs);
+	atomic64_set(&HFS_SB(sb)->file_count, be32_to_cpu(mdb->drFilCnt));
+	atomic64_set(&HFS_SB(sb)->folder_count, be32_to_cpu(mdb->drDirCnt));
+
+	if (!is_hfs_cnid_counts_valid(sb)) {
+		pr_warn("filesystem possibly corrupted, running fsck.hfs is recommended. Mounting read-only.\n");
+		sb->s_flags |= SB_RDONLY;
+	}
+
+	/* TRY to get the alternate (backup) MDB. */
+	sect = part_start + part_size - 2;
+	bh = sb_bread512(sb, sect, alt_mdb);
+	if (bh) {
+		if (alt_mdb->drSigWord == cpu_to_be16(HFS_SUPER_MAGIC)) {
+			alt_mdb = kmemdup(alt_mdb, HFS_SECTOR_SIZE, GFP_KERNEL);
+			if (alt_mdb) {
+				HFS_SB(sb)->alt_mdb_bh = bh;
+				HFS_SB(sb)->alt_mdb_offset =
+					hfs_sect_offset(sb, sect);
+				HFS_SB(sb)->alt_mdb = alt_mdb;
+			} else {
+				brelse(bh);
+			}
+		} else
+			brelse(bh);
+	}
+
+	if (!HFS_SB(sb)->alt_mdb) {
+		pr_warn("unable to locate alternate MDB\n");
+		pr_warn("continuing without an alternate MDB\n");
+	}
+
+	HFS_SB(sb)->bitmap = kzalloc(8192, GFP_KERNEL);
+	if (!HFS_SB(sb)->bitmap)
+		return -EIO;
+
+	/* read in the bitmap */
+	block = be16_to_cpu(mdb->drVBMSt) + part_start;
+	off = (loff_t)block << HFS_SECTOR_SIZE_BITS;
+	size = (HFS_SB(sb)->fs_ablocks + 8) / 8;
+	ptr = (u8 *)HFS_SB(sb)->bitmap;
+	while (size) {
+		bh = sb_bread(sb, off >> sb->s_blocksize_bits);
+		if (!bh) {
+			pr_err("unable to read volume bitmap\n");
+			return -EIO;
+		}
+		off2 = off & (sb->s_blocksize - 1);
+		len = min((int)sb->s_blocksize - off2, size);
+		memcpy(ptr, bh->b_data + off2, len);
+		brelse(bh);
+		ptr += len;
+		off += len;
+		size -= len;
+	}
+
+	HFS_SB(sb)->ext_tree = hfs_btree_open(sb, HFS_EXT_CNID, hfs_ext_keycmp);
+	if (!HFS_SB(sb)->ext_tree) {
+		pr_err("unable to open extent tree\n");
+		return -EIO;
+	}
+	HFS_SB(sb)->cat_tree = hfs_btree_open(sb, HFS_CAT_CNID, hfs_cat_keycmp);
+	if (!HFS_SB(sb)->cat_tree) {
+		pr_err("unable to open catalog tree\n");
+		return -EIO;
+	}
+
+	attrib = mdb->drAtrb;
+	if (!(attrib & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
+		pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.	Mounting read-only.\n");
+		sb->s_flags |= SB_RDONLY;
+	}
+	if ((attrib & cpu_to_be16(HFS_SB_ATTRIB_SLOCK))) {
+		pr_warn("filesystem is marked locked, mounting read-only.\n");
+		sb->s_flags |= SB_RDONLY;
+	}
+	if (!sb_rdonly(sb)) {
+		/* Mark the volume uncleanly unmounted in case we crash */
+		attrib &= cpu_to_be16(~HFS_SB_ATTRIB_UNMNT);
+		attrib |= cpu_to_be16(HFS_SB_ATTRIB_INCNSTNT);
+		mdb->drAtrb = attrib;
+		be32_add_cpu(&mdb->drWrCnt, 1);
+		mdb->drLsMod = hfs_mtime();
+
+		hfs_mdb_publish(HFS_SB(sb));
+		sync_dirty_buffer(HFS_SB(sb)->mdb_bh);
+	}
+
+	return 0;
+}
+
+/*
+ * hfs_mdb_commit()
+ *
+ * Description:
+ *   This updates the MDB on disk.
+ *   It does not check, if the superblock has been modified, or
+ *   if the filesystem has been mounted read-only. It is mainly
+ *   called by hfs_sync_fs() and flush_mdb().
+ * Input Variable(s):
+ *   struct hfs_mdb *mdb: Pointer to the hfs MDB
+ *   int backup;
+ * Output Variable(s):
+ *   NONE
+ * Returns:
+ *   0 on success, -EIO if the MDB or alternate MDB buffer is no longer
+ *   valid (e.g. after a prior write error), in which case the volume is
+ *   remounted read-only.
+ * Preconditions:
+ *   'mdb' points to a "valid" (struct hfs_mdb).
+ * Postconditions:
+ *   The HFS MDB and on disk will be updated, by copying the possibly
+ *   modified fields from the in memory MDB (in native byte order) to
+ *   the disk block buffer.
+ *   If 'backup' is non-zero then the alternate MDB is also written
+ *   and the function doesn't return until it is actually on disk.
+ */
+int hfs_mdb_commit(struct super_block *sb)
+{
+	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
+	int ret = 0;
+
+	if (sb_rdonly(sb))
+		return 0;
+
+	if (!buffer_uptodate(HFS_SB(sb)->mdb_bh)) {
+		pr_err("primary MDB is corrupt, mounting read-only\n");
+		sb->s_flags |= SB_RDONLY;
+		return -EIO;
+	}
+
+	if (test_and_clear_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags)) {
+		/* These parameters may have been modified, so write them back */
+		mdb->drLsMod = hfs_mtime();
+		mdb->drFreeBks = cpu_to_be16(HFS_SB(sb)->free_ablocks);
+		mdb->drNxtCNID =
+			cpu_to_be32((u32)atomic64_read(&HFS_SB(sb)->next_id));
+		mdb->drNmFls = cpu_to_be16(HFS_SB(sb)->root_files);
+		mdb->drNmRtDirs = cpu_to_be16(HFS_SB(sb)->root_dirs);
+		mdb->drFilCnt =
+			cpu_to_be32((u32)atomic64_read(&HFS_SB(sb)->file_count));
+		mdb->drDirCnt =
+			cpu_to_be32((u32)atomic64_read(&HFS_SB(sb)->folder_count));
+
+		hfs_inode_write_fork(HFS_SB(sb)->ext_tree->inode, mdb->drXTExtRec,
+				     &mdb->drXTFlSize, NULL);
+		hfs_inode_write_fork(HFS_SB(sb)->cat_tree->inode, mdb->drCTExtRec,
+				     &mdb->drCTFlSize, NULL);
+
+		/* write MDB to disk */
+		hfs_mdb_publish(HFS_SB(sb));
+		sync_dirty_buffer(HFS_SB(sb)->mdb_bh);
+	}
+
+	/* write the backup MDB, not returning until it is written.
+	 * we only do this when either the catalog or extents overflow
+	 * files grow. */
+	if (test_and_clear_bit(HFS_FLG_ALT_MDB_DIRTY, &HFS_SB(sb)->flags) &&
+	    HFS_SB(sb)->alt_mdb) {
+		if (!buffer_uptodate(HFS_SB(sb)->alt_mdb_bh)) {
+			pr_err("alternate MDB is corrupt, mounting read-only\n");
+			sb->s_flags |= SB_RDONLY;
+			ret = -EIO;
+			goto out;
+		}
+
+		memcpy(HFS_SB(sb)->alt_mdb, mdb, HFS_SECTOR_SIZE);
+		HFS_SB(sb)->alt_mdb->drAtrb |= cpu_to_be16(HFS_SB_ATTRIB_UNMNT);
+		HFS_SB(sb)->alt_mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT);
+
+		hfs_alt_mdb_publish(HFS_SB(sb));
+		sync_dirty_buffer(HFS_SB(sb)->alt_mdb_bh);
+	}
+
+	if (test_and_clear_bit(HFS_FLG_BITMAP_DIRTY, &HFS_SB(sb)->flags)) {
+		struct buffer_head *bh;
+		sector_t block;
+		char *ptr;
+		int off, size, len;
+
+		block = be16_to_cpu(HFS_SB(sb)->mdb->drVBMSt) + HFS_SB(sb)->part_start;
+		off = (block << HFS_SECTOR_SIZE_BITS) & (sb->s_blocksize - 1);
+		block >>= sb->s_blocksize_bits - HFS_SECTOR_SIZE_BITS;
+		size = (HFS_SB(sb)->fs_ablocks + 7) / 8;
+		ptr = (u8 *)HFS_SB(sb)->bitmap;
+		while (size) {
+			bh = sb_bread(sb, block);
+			if (!bh) {
+				pr_err("unable to read volume bitmap\n");
+				break;
+			}
+			len = min((int)sb->s_blocksize - off, size);
+
+			lock_buffer(bh);
+			memcpy(bh->b_data + off, ptr, len);
+			unlock_buffer(bh);
+
+			mark_buffer_dirty(bh);
+			brelse(bh);
+			block++;
+			off = 0;
+			ptr += len;
+			size -= len;
+		}
+	}
+out:
+	return ret;
+}
+
+void hfs_mdb_close(struct super_block *sb)
+{
+	/* update volume attributes */
+	if (sb_rdonly(sb))
+		return;
+
+	if (!buffer_uptodate(HFS_SB(sb)->mdb_bh))
+		return;
+
+	HFS_SB(sb)->mdb->drAtrb |= cpu_to_be16(HFS_SB_ATTRIB_UNMNT);
+	HFS_SB(sb)->mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT);
+	hfs_mdb_publish(HFS_SB(sb));
+}
+
+/*
+ * hfs_mdb_put()
+ *
+ * Release the resources associated with the in-core MDB.  */
+void hfs_mdb_put(struct super_block *sb)
+{
+	/* free the B-trees */
+	hfs_btree_close(HFS_SB(sb)->ext_tree);
+	hfs_btree_close(HFS_SB(sb)->cat_tree);
+
+	/* free the buffers holding the primary and alternate MDBs */
+	brelse(HFS_SB(sb)->mdb_bh);
+	brelse(HFS_SB(sb)->alt_mdb_bh);
+	kfree(HFS_SB(sb)->mdb);
+	kfree(HFS_SB(sb)->alt_mdb);
+
+	unload_nls(HFS_SB(sb)->nls_io);
+	unload_nls(HFS_SB(sb)->nls_disk);
+
+	kfree(HFS_SB(sb)->bitmap);
+}
diff --git a/fs/hfs/part_tbl.c b/fs/hfs/part_tbl.c
new file mode 100644
index 000000000..36add537d
--- /dev/null
+++ b/fs/hfs/part_tbl.c
@@ -0,0 +1,117 @@
+/*
+ *  linux/fs/hfs/part_tbl.c
+ *
+ * Copyright (C) 1996-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * Original code to handle the new style Mac partition table based on
+ * a patch contributed by Holger Schemel (aeglos@valinor.owl.de).
+ */
+
+#include "hfs_fs.h"
+
+/*
+ * The new style Mac partition map
+ *
+ * For each partition on the media there is a physical block (512-byte
+ * block) containing one of these structures.  These blocks are
+ * contiguous starting at block 1.
+ */
+struct new_pmap {
+	__be16	pmSig;		/* signature */
+	__be16	reSigPad;	/* padding */
+	__be32	pmMapBlkCnt;	/* partition blocks count */
+	__be32	pmPyPartStart;	/* physical block start of partition */
+	__be32	pmPartBlkCnt;	/* physical block count of partition */
+	u8	pmPartName[32];	/* (null terminated?) string
+				   giving the name of this
+				   partition */
+	u8	pmPartType[32];	/* (null terminated?) string
+				   giving the type of this
+				   partition */
+	/* a bunch more stuff we don't need */
+} __packed;
+
+/*
+ * The old style Mac partition map
+ *
+ * The partition map consists for a 2-byte signature followed by an
+ * array of these structures.  The map is terminated with an all-zero
+ * one of these.
+ */
+struct old_pmap {
+	__be16		pdSig;	/* Signature bytes */
+	struct 	old_pmap_entry {
+		__be32	pdStart;
+		__be32	pdSize;
+		__be32	pdFSID;
+	}	pdEntry[42];
+} __packed;
+
+/*
+ * hfs_part_find()
+ *
+ * Parse the partition map looking for the
+ * start and length of the 'part'th HFS partition.
+ */
+int hfs_part_find(struct super_block *sb,
+		  sector_t *part_start, sector_t *part_size)
+{
+	struct buffer_head *bh;
+	__be16 *data;
+	int i, size, res;
+
+	res = -ENOENT;
+	bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK, data);
+	if (!bh)
+		return -EIO;
+
+	switch (be16_to_cpu(*data)) {
+	case HFS_OLD_PMAP_MAGIC:
+	  {
+		struct old_pmap *pm;
+		struct old_pmap_entry *p;
+
+		pm = (struct old_pmap *)bh->b_data;
+		p = pm->pdEntry;
+		size = 42;
+		for (i = 0; i < size; p++, i++) {
+			if (p->pdStart && p->pdSize &&
+			    p->pdFSID == cpu_to_be32(0x54465331)/*"TFS1"*/ &&
+			    (HFS_SB(sb)->part < 0 || HFS_SB(sb)->part == i)) {
+				*part_start += be32_to_cpu(p->pdStart);
+				*part_size = be32_to_cpu(p->pdSize);
+				res = 0;
+			}
+		}
+		break;
+	  }
+	case HFS_NEW_PMAP_MAGIC:
+	  {
+		struct new_pmap *pm;
+
+		pm = (struct new_pmap *)bh->b_data;
+		size = be32_to_cpu(pm->pmMapBlkCnt);
+		for (i = 0; i < size;) {
+			if (!memcmp(pm->pmPartType,"Apple_HFS", 9) &&
+			    (HFS_SB(sb)->part < 0 || HFS_SB(sb)->part == i)) {
+				*part_start += be32_to_cpu(pm->pmPyPartStart);
+				*part_size = be32_to_cpu(pm->pmPartBlkCnt);
+				res = 0;
+				break;
+			}
+			brelse(bh);
+			bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK + ++i, pm);
+			if (!bh)
+				return -EIO;
+			if (pm->pmSig != cpu_to_be16(HFS_NEW_PMAP_MAGIC))
+				break;
+		}
+		break;
+	  }
+	}
+	brelse(bh);
+
+	return res;
+}
diff --git a/fs/hfs/string.c b/fs/hfs/string.c
new file mode 100644
index 000000000..0cfa35e82
--- /dev/null
+++ b/fs/hfs/string.c
@@ -0,0 +1,119 @@
+/*
+ *  linux/fs/hfs/string.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains the string comparison function for the
+ * Macintosh character set.
+ *
+ * The code in this file is derived from code which is copyright
+ * 1986, 1989, 1990 by Abacus Research and Development, Inc. (ARDI)
+ * It is used here by the permission of ARDI's president Cliff Matthews.
+ */
+
+#include "hfs_fs.h"
+#include <linux/dcache.h>
+
+#include <kunit/visibility.h>
+
+/*================ File-local variables ================*/
+
+/*
+ * unsigned char caseorder[]
+ *
+ * Defines the lexical ordering of characters on the Macintosh
+ *
+ * Composition of the 'casefold' and 'order' tables from ARDI's code
+ * with the entry for 0x20 changed to match that for 0xCA to remove
+ * special case for those two characters.
+ */
+static unsigned char caseorder[256] = {
+	0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
+	0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
+	0x20,0x22,0x23,0x28,0x29,0x2A,0x2B,0x2C,0x2F,0x30,0x31,0x32,0x33,0x34,0x35,0x36,
+	0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,0x40,0x41,0x42,0x43,0x44,0x45,0x46,
+	0x47,0x48,0x57,0x59,0x5D,0x5F,0x66,0x68,0x6A,0x6C,0x72,0x74,0x76,0x78,0x7A,0x7E,
+	0x8C,0x8E,0x90,0x92,0x95,0x97,0x9E,0xA0,0xA2,0xA4,0xA7,0xA9,0xAA,0xAB,0xAC,0xAD,
+	0x4E,0x48,0x57,0x59,0x5D,0x5F,0x66,0x68,0x6A,0x6C,0x72,0x74,0x76,0x78,0x7A,0x7E,
+	0x8C,0x8E,0x90,0x92,0x95,0x97,0x9E,0xA0,0xA2,0xA4,0xA7,0xAF,0xB0,0xB1,0xB2,0xB3,
+	0x4A,0x4C,0x5A,0x60,0x7B,0x7F,0x98,0x4F,0x49,0x51,0x4A,0x4B,0x4C,0x5A,0x60,0x63,
+	0x64,0x65,0x6E,0x6F,0x70,0x71,0x7B,0x84,0x85,0x86,0x7F,0x80,0x9A,0x9B,0x9C,0x98,
+	0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0x94,0xBB,0xBC,0xBD,0xBE,0xBF,0xC0,0x4D,0x81,
+	0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xCB,0x55,0x8A,0xCC,0x4D,0x81,
+	0xCD,0xCE,0xCF,0xD0,0xD1,0xD2,0xD3,0x26,0x27,0xD4,0x20,0x49,0x4B,0x80,0x82,0x82,
+	0xD5,0xD6,0x24,0x25,0x2D,0x2E,0xD7,0xD8,0xA6,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
+	0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
+	0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF
+};
+
+/*================ Global functions ================*/
+
+/*
+ * Hash a string to an integer in a case-independent way
+ */
+int hfs_hash_dentry(const struct dentry *dentry, struct qstr *this)
+{
+	const unsigned char *name = this->name;
+	unsigned int hash, len = this->len;
+
+	if (len > HFS_NAMELEN)
+		len = HFS_NAMELEN;
+
+	hash = init_name_hash(dentry);
+	for (; len; len--)
+		hash = partial_name_hash(caseorder[*name++], hash);
+	this->hash = end_name_hash(hash);
+	return 0;
+}
+EXPORT_SYMBOL_IF_KUNIT(hfs_hash_dentry);
+
+/*
+ * Compare two strings in the HFS filename character ordering
+ * Returns positive, negative, or zero, not just 0 or (+/-)1
+ *
+ * Equivalent to ARDI's call:
+ *	ROMlib_RelString(s1+1, s2+1, true, false, (s1[0]<<16) | s2[0])
+ */
+int hfs_strcmp(const unsigned char *s1, unsigned int len1,
+	       const unsigned char *s2, unsigned int len2)
+{
+	int len, tmp;
+
+	len = (len1 > len2) ? len2 : len1;
+
+	while (len--) {
+		tmp = (int)caseorder[*(s1++)] - (int)caseorder[*(s2++)];
+		if (tmp)
+			return tmp;
+	}
+	return len1 - len2;
+}
+EXPORT_SYMBOL_IF_KUNIT(hfs_strcmp);
+
+/*
+ * Test for equality of two strings in the HFS filename character ordering.
+ * return 1 on failure and 0 on success
+ */
+int hfs_compare_dentry(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name)
+{
+	const unsigned char *n1, *n2;
+
+	if (len >= HFS_NAMELEN) {
+		if (name->len < HFS_NAMELEN)
+			return 1;
+		len = HFS_NAMELEN;
+	} else if (len != name->len)
+		return 1;
+
+	n1 = str;
+	n2 = name->name;
+	while (len--) {
+		if (caseorder[*n1++] != caseorder[*n2++])
+			return 1;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_IF_KUNIT(hfs_compare_dentry);
diff --git a/fs/hfs/string_test.c b/fs/hfs/string_test.c
new file mode 100644
index 000000000..e1bf6f954
--- /dev/null
+++ b/fs/hfs/string_test.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for HFS string operations
+ *
+ * Copyright (C) 2025 Viacheslav Dubeyko <slava@dubeyko.com>
+ */
+
+#include <kunit/test.h>
+#include <linux/dcache.h>
+#include "hfs_fs.h"
+
+/* Test hfs_strcmp function */
+static void hfs_strcmp_test(struct kunit *test)
+{
+	/* Test equal strings */
+	KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("hello", 5, "hello", 5));
+	KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("test", 4, "test", 4));
+	KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("", 0, "", 0));
+
+	/* Test unequal strings */
+	KUNIT_EXPECT_NE(test, 0, hfs_strcmp("hello", 5, "world", 5));
+	KUNIT_EXPECT_NE(test, 0, hfs_strcmp("test", 4, "testing", 7));
+
+	/* Test different lengths */
+	KUNIT_EXPECT_LT(test, hfs_strcmp("test", 4, "testing", 7), 0);
+	KUNIT_EXPECT_GT(test, hfs_strcmp("testing", 7, "test", 4), 0);
+
+	/* Test case insensitive comparison (HFS should handle case) */
+	KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("Test", 4, "TEST", 4));
+	KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("hello", 5, "HELLO", 5));
+
+	/* Test with special characters */
+	KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("file.txt", 8, "file.txt", 8));
+	KUNIT_EXPECT_NE(test, 0, hfs_strcmp("file.txt", 8, "file.dat", 8));
+
+	/* Test boundary cases */
+	KUNIT_EXPECT_EQ(test, 0, hfs_strcmp("a", 1, "a", 1));
+	KUNIT_EXPECT_NE(test, 0, hfs_strcmp("a", 1, "b", 1));
+}
+
+/* Test hfs_hash_dentry function */
+static void hfs_hash_dentry_test(struct kunit *test)
+{
+	struct qstr test_name1, test_name2, test_name3;
+	struct dentry dentry = {};
+	char name1[] = "testfile";
+	char name2[] = "TestFile";
+	char name3[] = "different";
+
+	/* Initialize test strings */
+	test_name1.name = name1;
+	test_name1.len = strlen(name1);
+	test_name1.hash = 0;
+
+	test_name2.name = name2;
+	test_name2.len = strlen(name2);
+	test_name2.hash = 0;
+
+	test_name3.name = name3;
+	test_name3.len = strlen(name3);
+	test_name3.hash = 0;
+
+	/* Test hashing */
+	KUNIT_EXPECT_EQ(test, 0, hfs_hash_dentry(&dentry, &test_name1));
+	KUNIT_EXPECT_EQ(test, 0, hfs_hash_dentry(&dentry, &test_name2));
+	KUNIT_EXPECT_EQ(test, 0, hfs_hash_dentry(&dentry, &test_name3));
+
+	/* Case insensitive names should hash the same */
+	KUNIT_EXPECT_EQ(test, test_name1.hash, test_name2.hash);
+
+	/* Different names should have different hashes */
+	KUNIT_EXPECT_NE(test, test_name1.hash, test_name3.hash);
+}
+
+/* Test hfs_compare_dentry function */
+static void hfs_compare_dentry_test(struct kunit *test)
+{
+	struct qstr test_name;
+	struct dentry dentry = {};
+	char name[] = "TestFile";
+
+	test_name.name = name;
+	test_name.len = strlen(name);
+
+	/* Test exact match */
+	KUNIT_EXPECT_EQ(test, 0, hfs_compare_dentry(&dentry, 8,
+						    "TestFile", &test_name));
+
+	/* Test case insensitive match */
+	KUNIT_EXPECT_EQ(test, 0, hfs_compare_dentry(&dentry, 8,
+						    "testfile", &test_name));
+	KUNIT_EXPECT_EQ(test, 0, hfs_compare_dentry(&dentry, 8,
+						    "TESTFILE", &test_name));
+
+	/* Test different names */
+	KUNIT_EXPECT_EQ(test, 1, hfs_compare_dentry(&dentry, 8,
+						    "DiffFile", &test_name));
+
+	/* Test different lengths */
+	KUNIT_EXPECT_EQ(test, 1, hfs_compare_dentry(&dentry, 7,
+						    "TestFil", &test_name));
+	KUNIT_EXPECT_EQ(test, 1, hfs_compare_dentry(&dentry, 9,
+						    "TestFiles", &test_name));
+
+	/* Test empty string */
+	test_name.name = "";
+	test_name.len = 0;
+	KUNIT_EXPECT_EQ(test, 0, hfs_compare_dentry(&dentry, 0, "", &test_name));
+
+	/* Test HFS_NAMELEN boundary */
+	test_name.name = "This_is_a_very_long_filename_that_exceeds_normal_limits";
+	test_name.len = strlen(test_name.name);
+	KUNIT_EXPECT_EQ(test, 0, hfs_compare_dentry(&dentry, HFS_NAMELEN,
+			"This_is_a_very_long_filename_th", &test_name));
+}
+
+static struct kunit_case hfs_string_test_cases[] = {
+	KUNIT_CASE(hfs_strcmp_test),
+	KUNIT_CASE(hfs_hash_dentry_test),
+	KUNIT_CASE(hfs_compare_dentry_test),
+	{}
+};
+
+static struct kunit_suite hfs_string_test_suite = {
+	.name = "hfs_string",
+	.test_cases = hfs_string_test_cases,
+};
+
+kunit_test_suite(hfs_string_test_suite);
+
+MODULE_DESCRIPTION("KUnit tests for HFS string operations");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
new file mode 100644
index 000000000..5e6d66ff4
--- /dev/null
+++ b/fs/hfs/super.c
@@ -0,0 +1,503 @@
+/*
+ *  linux/fs/hfs/super.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains hfs_read_super(), some of the super_ops and
+ * init_hfs_fs() and exit_hfs_fs().  The remaining super_ops are in
+ * inode.c since they deal with inodes.
+ *
+ * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
+ */
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/mount.h>
+#include <linux/init.h>
+#include <linux/nls.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/vfs.h>
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+static struct kmem_cache *hfs_inode_cachep;
+
+MODULE_DESCRIPTION("Apple Macintosh file system support");
+MODULE_LICENSE("GPL");
+
+static int hfs_sync_fs(struct super_block *sb, int wait)
+{
+	int ret;
+
+	mutex_lock(&HFS_SB(sb)->mdb_lock);
+	is_hfs_cnid_counts_valid(sb);
+	ret = hfs_mdb_commit(sb);
+	mutex_unlock(&HFS_SB(sb)->mdb_lock);
+
+	return ret;
+}
+
+/*
+ * hfs_put_super()
+ *
+ * This is the put_super() entry in the super_operations structure for
+ * HFS filesystems.  The purpose is to release the resources
+ * associated with the superblock sb.
+ */
+static void hfs_put_super(struct super_block *sb)
+{
+	cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
+	hfs_mdb_close(sb);
+	/* release the MDB's resources */
+	hfs_mdb_put(sb);
+}
+
+static void flush_mdb(struct work_struct *work)
+{
+	struct hfs_sb_info *sbi;
+	struct super_block *sb;
+
+	sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
+	sb = sbi->sb;
+
+	spin_lock(&sbi->work_lock);
+	sbi->work_queued = 0;
+	spin_unlock(&sbi->work_lock);
+
+	mutex_lock(&sbi->mdb_lock);
+	is_hfs_cnid_counts_valid(sb);
+	hfs_mdb_commit(sb);
+	mutex_unlock(&sbi->mdb_lock);
+}
+
+void hfs_mark_mdb_dirty(struct super_block *sb)
+{
+	struct hfs_sb_info *sbi = HFS_SB(sb);
+	unsigned long delay;
+
+	if (sb_rdonly(sb))
+		return;
+
+	spin_lock(&sbi->work_lock);
+	if (!sbi->work_queued) {
+		delay = msecs_to_jiffies(dirty_writeback_interval * 10);
+		queue_delayed_work(system_dfl_long_wq, &sbi->mdb_work, delay);
+		sbi->work_queued = 1;
+	}
+	spin_unlock(&sbi->work_lock);
+}
+
+/*
+ * hfs_statfs()
+ *
+ * This is the statfs() entry in the super_operations structure for
+ * HFS filesystems.  The purpose is to return various data about the
+ * filesystem.
+ *
+ * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
+ */
+static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+	buf->f_type = HFS_SUPER_MAGIC;
+	buf->f_bsize = sb->s_blocksize;
+	buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
+	buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
+	buf->f_bavail = buf->f_bfree;
+	buf->f_files = HFS_SB(sb)->fs_ablocks;
+	buf->f_ffree = HFS_SB(sb)->free_ablocks;
+	buf->f_fsid = u64_to_fsid(id);
+	buf->f_namelen = HFS_NAMELEN;
+
+	return 0;
+}
+
+static int hfs_reconfigure(struct fs_context *fc)
+{
+	struct super_block *sb = fc->root->d_sb;
+
+	sync_filesystem(sb);
+	fc->sb_flags |= SB_NODIRATIME;
+	if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
+		return 0;
+
+	if (!(fc->sb_flags & SB_RDONLY)) {
+		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
+			pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
+			sb->s_flags |= SB_RDONLY;
+			fc->sb_flags |= SB_RDONLY;
+		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
+			pr_warn("filesystem is marked locked, leaving read-only.\n");
+			sb->s_flags |= SB_RDONLY;
+			fc->sb_flags |= SB_RDONLY;
+		}
+	}
+	return 0;
+}
+
+static int hfs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
+
+	if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
+		seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
+	if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
+		seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
+	seq_printf(seq, ",uid=%u,gid=%u",
+			from_kuid_munged(&init_user_ns, sbi->s_uid),
+			from_kgid_munged(&init_user_ns, sbi->s_gid));
+	if (sbi->s_file_umask != 0133)
+		seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
+	if (sbi->s_dir_umask != 0022)
+		seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
+	if (sbi->part >= 0)
+		seq_printf(seq, ",part=%u", sbi->part);
+	if (sbi->session >= 0)
+		seq_printf(seq, ",session=%u", sbi->session);
+	if (sbi->nls_disk)
+		seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
+	if (sbi->nls_io)
+		seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
+	if (sbi->s_quiet)
+		seq_printf(seq, ",quiet");
+	return 0;
+}
+
+static struct inode *hfs_alloc_inode(struct super_block *sb)
+{
+	struct hfs_inode_info *i;
+
+	i = alloc_inode_sb(sb, hfs_inode_cachep, GFP_KERNEL);
+	return i ? &i->vfs_inode : NULL;
+}
+
+static void hfs_free_inode(struct inode *inode)
+{
+	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
+}
+
+static const struct super_operations hfs_super_operations = {
+	.alloc_inode	= hfs_alloc_inode,
+	.free_inode	= hfs_free_inode,
+	.write_inode	= hfs_write_inode,
+	.evict_inode	= hfs_evict_inode,
+	.put_super	= hfs_put_super,
+	.sync_fs	= hfs_sync_fs,
+	.statfs		= hfs_statfs,
+	.show_options	= hfs_show_options,
+};
+
+enum {
+	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
+	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
+	opt_codepage, opt_iocharset,
+};
+
+static const struct fs_parameter_spec hfs_param_spec[] = {
+	fsparam_u32	("uid",		opt_uid),
+	fsparam_u32	("gid",		opt_gid),
+	fsparam_u32oct	("umask",	opt_umask),
+	fsparam_u32oct	("file_umask",	opt_file_umask),
+	fsparam_u32oct	("dir_umask",	opt_dir_umask),
+	fsparam_u32	("part",	opt_part),
+	fsparam_u32	("session",	opt_session),
+	fsparam_string	("type",	opt_type),
+	fsparam_string	("creator",	opt_creator),
+	fsparam_flag	("quiet",	opt_quiet),
+	fsparam_string	("codepage",	opt_codepage),
+	fsparam_string	("iocharset",	opt_iocharset),
+	{}
+};
+
+/*
+ * hfs_parse_param()
+ *
+ * This function is called by the vfs to parse the mount options.
+ */
+static int hfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct hfs_sb_info *hsb = fc->s_fs_info;
+	struct fs_parse_result result;
+	int opt;
+
+	/* hfs does not honor any fs-specific options on remount */
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
+		return 0;
+
+	opt = fs_parse(fc, hfs_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case opt_uid:
+		hsb->s_uid = result.uid;
+		break;
+	case opt_gid:
+		hsb->s_gid = result.gid;
+		break;
+	case opt_umask:
+		hsb->s_file_umask = (umode_t)result.uint_32;
+		hsb->s_dir_umask = (umode_t)result.uint_32;
+		break;
+	case opt_file_umask:
+		hsb->s_file_umask = (umode_t)result.uint_32;
+		break;
+	case opt_dir_umask:
+		hsb->s_dir_umask = (umode_t)result.uint_32;
+		break;
+	case opt_part:
+		hsb->part = result.uint_32;
+		break;
+	case opt_session:
+		hsb->session = result.uint_32;
+		break;
+	case opt_type:
+		if (strlen(param->string) != 4) {
+			pr_err("type requires a 4 character value\n");
+			return -EINVAL;
+		}
+		memcpy(&hsb->s_type, param->string, 4);
+		break;
+	case opt_creator:
+		if (strlen(param->string) != 4) {
+			pr_err("creator requires a 4 character value\n");
+			return -EINVAL;
+		}
+		memcpy(&hsb->s_creator, param->string, 4);
+		break;
+	case opt_quiet:
+		hsb->s_quiet = 1;
+		break;
+	case opt_codepage:
+		if (hsb->nls_disk) {
+			pr_err("unable to change codepage\n");
+			return -EINVAL;
+		}
+		hsb->nls_disk = load_nls(param->string);
+		if (!hsb->nls_disk) {
+			pr_err("unable to load codepage \"%s\"\n",
+					param->string);
+			return -EINVAL;
+		}
+		break;
+	case opt_iocharset:
+		if (hsb->nls_io) {
+			pr_err("unable to change iocharset\n");
+			return -EINVAL;
+		}
+		hsb->nls_io = load_nls(param->string);
+		if (!hsb->nls_io) {
+			pr_err("unable to load iocharset \"%s\"\n",
+					param->string);
+			return -EINVAL;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * hfs_read_super()
+ *
+ * This is the function that is responsible for mounting an HFS
+ * filesystem.	It performs all the tasks necessary to get enough data
+ * from the disk to read the root inode.  This includes parsing the
+ * mount options, dealing with Macintosh partitions, reading the
+ * superblock and the allocation bitmap blocks, calling
+ * hfs_btree_init() to get the necessary data about the extents and
+ * catalog B-trees and, finally, reading the root inode into memory.
+ */
+static int hfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct hfs_sb_info *sbi = HFS_SB(sb);
+	struct hfs_find_data fd;
+	hfs_cat_rec rec;
+	struct inode *root_inode;
+	int silent = fc->sb_flags & SB_SILENT;
+	int res;
+
+	atomic64_set(&sbi->file_count, 0);
+	atomic64_set(&sbi->folder_count, 0);
+	atomic64_set(&sbi->next_id, 0);
+
+	/* load_nls_default does not fail */
+	if (sbi->nls_disk && !sbi->nls_io)
+		sbi->nls_io = load_nls_default();
+	sbi->s_dir_umask &= 0777;
+	sbi->s_file_umask &= 0577;
+
+	spin_lock_init(&sbi->work_lock);
+	INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
+
+	sbi->sb = sb;
+	sb->s_op = &hfs_super_operations;
+	sb->s_xattr = hfs_xattr_handlers;
+	sb->s_flags |= SB_NOATIME | SB_NODIRATIME;
+	mutex_init(&sbi->mdb_lock);
+	mutex_init(&sbi->bitmap_lock);
+
+	mutex_lock(&sbi->mdb_lock);
+	res = hfs_mdb_get(sb);
+	mutex_unlock(&sbi->mdb_lock);
+	if (res) {
+		if (!silent)
+			pr_warn("can't find a HFS filesystem on dev %s\n",
+				hfs_mdb_name(sb));
+		res = -EINVAL;
+		goto bail;
+	}
+
+	/* try to get the root inode */
+	res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
+	if (res)
+		goto bail_no_root;
+	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
+	if (!res) {
+		if (fd.entrylength != sizeof(rec.dir)) {
+			res =  -EIO;
+			goto bail_hfs_find;
+		}
+		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
+		if (rec.type != HFS_CDR_DIR)
+			res = -EIO;
+	}
+	if (res)
+		goto bail_hfs_find;
+	res = -EINVAL;
+	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
+	hfs_find_exit(&fd);
+	if (!root_inode)
+		goto bail_no_root;
+
+	if (is_bad_inode(root_inode)) {
+		iput(root_inode);
+		goto bail_no_root;
+	}
+
+	set_default_d_op(sb, &hfs_dentry_operations);
+	res = -ENOMEM;
+	sb->s_root = d_make_root(root_inode);
+	if (!sb->s_root)
+		goto bail_no_root;
+
+	/* everything's okay */
+	return 0;
+
+bail_hfs_find:
+	hfs_find_exit(&fd);
+bail_no_root:
+	pr_err("get root inode failed\n");
+bail:
+	hfs_mdb_put(sb);
+	return res;
+}
+
+static int hfs_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, hfs_fill_super);
+}
+
+static void hfs_free_fc(struct fs_context *fc)
+{
+	kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations hfs_context_ops = {
+	.parse_param	= hfs_parse_param,
+	.get_tree	= hfs_get_tree,
+	.reconfigure	= hfs_reconfigure,
+	.free		= hfs_free_fc,
+};
+
+static int hfs_init_fs_context(struct fs_context *fc)
+{
+	struct hfs_sb_info *hsb;
+
+	hsb = kzalloc_obj(struct hfs_sb_info);
+	if (!hsb)
+		return -ENOMEM;
+
+	fc->s_fs_info = hsb;
+	fc->ops = &hfs_context_ops;
+
+	if (fc->purpose != FS_CONTEXT_FOR_RECONFIGURE) {
+		/* initialize options with defaults */
+		hsb->s_uid = current_uid();
+		hsb->s_gid = current_gid();
+		hsb->s_file_umask = 0133;
+		hsb->s_dir_umask = 0022;
+		hsb->s_type = cpu_to_be32(0x3f3f3f3f); /* == '????' */
+		hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
+		hsb->s_quiet = 0;
+		hsb->part = -1;
+		hsb->session = -1;
+	}
+
+	return 0;
+}
+
+static void hfs_kill_super(struct super_block *sb)
+{
+	struct hfs_sb_info *hsb = HFS_SB(sb);
+
+	kill_block_super(sb);
+	kfree(hsb);
+}
+
+static struct file_system_type hfs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "hfs",
+	.kill_sb	= hfs_kill_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+	.init_fs_context = hfs_init_fs_context,
+};
+MODULE_ALIAS_FS("hfs");
+
+static void hfs_init_once(void *p)
+{
+	struct hfs_inode_info *i = p;
+
+	inode_init_once(&i->vfs_inode);
+}
+
+static int __init init_hfs_fs(void)
+{
+	int err;
+
+	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
+		sizeof(struct hfs_inode_info), 0,
+		SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
+	if (!hfs_inode_cachep)
+		return -ENOMEM;
+	err = register_filesystem(&hfs_fs_type);
+	if (err)
+		kmem_cache_destroy(hfs_inode_cachep);
+	return err;
+}
+
+static void __exit exit_hfs_fs(void)
+{
+	unregister_filesystem(&hfs_fs_type);
+
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(hfs_inode_cachep);
+}
+
+module_init(init_hfs_fs)
+module_exit(exit_hfs_fs)
diff --git a/fs/hfs/sysdep.c b/fs/hfs/sysdep.c
new file mode 100644
index 000000000..ef54fc809
--- /dev/null
+++ b/fs/hfs/sysdep.c
@@ -0,0 +1,50 @@
+/*
+ *  linux/fs/hfs/sysdep.c
+ *
+ * Copyright (C) 1996  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains the code to do various system dependent things.
+ */
+
+#include <linux/namei.h>
+#include "hfs_fs.h"
+
+/* dentry case-handling: just lowercase everything */
+
+static int hfs_revalidate_dentry(struct inode *dir, const struct qstr *name,
+				 struct dentry *dentry, unsigned int flags)
+{
+	struct inode *inode;
+	int diff;
+
+	if (flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	inode = d_inode(dentry);
+	if(!inode)
+		return 1;
+
+	/* fix up inode on a timezone change */
+	diff = sys_tz.tz_minuteswest * 60 - HFS_I(inode)->tz_secondswest;
+	if (diff) {
+		struct timespec64 ts = inode_get_ctime(inode);
+
+		inode_set_ctime(inode, ts.tv_sec + diff, ts.tv_nsec);
+		ts = inode_get_atime(inode);
+		inode_set_atime(inode, ts.tv_sec + diff, ts.tv_nsec);
+		ts = inode_get_mtime(inode);
+		inode_set_mtime(inode, ts.tv_sec + diff, ts.tv_nsec);
+		HFS_I(inode)->tz_secondswest += diff;
+	}
+	return 1;
+}
+
+const struct dentry_operations hfs_dentry_operations =
+{
+	.d_revalidate	= hfs_revalidate_dentry,
+	.d_hash		= hfs_hash_dentry,
+	.d_compare	= hfs_compare_dentry,
+};
+
diff --git a/fs/hfs/trans.c b/fs/hfs/trans.c
new file mode 100644
index 000000000..fdb0edb8a
--- /dev/null
+++ b/fs/hfs/trans.c
@@ -0,0 +1,150 @@
+/*
+ *  linux/fs/hfs/trans.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains routines for converting between the Macintosh
+ * character set and various other encodings.  This includes dealing
+ * with ':' vs. '/' as the path-element separator.
+ */
+
+#include <linux/types.h>
+#include <linux/nls.h>
+
+#include "hfs_fs.h"
+
+/*================ Global functions ================*/
+
+/*
+ * hfs_mac2asc()
+ *
+ * Given a 'Pascal String' (a string preceded by a length byte) in
+ * the Macintosh character set produce the corresponding filename using
+ * the 'trivial' name-mangling scheme, returning the length of the
+ * mangled filename.  Note that the output string is not NULL
+ * terminated.
+ *
+ * The name-mangling works as follows:
+ * The character '/', which is illegal in Linux filenames is replaced
+ * by ':' which never appears in HFS filenames.	 All other characters
+ * are passed unchanged from input to output.
+ */
+int hfs_mac2asc(struct super_block *sb, char *out, const struct hfs_name *in)
+{
+	struct nls_table *nls_disk = HFS_SB(sb)->nls_disk;
+	struct nls_table *nls_io = HFS_SB(sb)->nls_io;
+	const char *src;
+	char *dst;
+	int srclen, dstlen, size;
+
+	src = in->name;
+	srclen = in->len;
+	if (srclen > HFS_NAMELEN)
+		srclen = HFS_NAMELEN;
+	dst = out;
+	dstlen = HFS_MAX_NAMELEN;
+	if (nls_io) {
+		wchar_t ch;
+
+		while (srclen > 0) {
+			if (nls_disk) {
+				size = nls_disk->char2uni(src, srclen, &ch);
+				if (size <= 0) {
+					ch = '?';
+					size = 1;
+				}
+				src += size;
+				srclen -= size;
+			} else {
+				ch = *src++;
+				srclen--;
+			}
+			if (ch == '/')
+				ch = ':';
+			size = nls_io->uni2char(ch, dst, dstlen);
+			if (size < 0) {
+				if (size == -ENAMETOOLONG)
+					goto out;
+				*dst = '?';
+				size = 1;
+			}
+			dst += size;
+			dstlen -= size;
+		}
+	} else {
+		char ch;
+
+		while (--srclen >= 0)
+			*dst++ = (ch = *src++) == '/' ? ':' : ch;
+	}
+out:
+	return dst - out;
+}
+
+/*
+ * hfs_asc2mac()
+ *
+ * Given an ASCII string (not null-terminated) and its length,
+ * generate the corresponding filename in the Macintosh character set
+ * using the 'trivial' name-mangling scheme, returning the length of
+ * the mangled filename.  Note that the output string is not NULL
+ * terminated.
+ *
+ * This routine is a inverse to hfs_mac2triv().
+ * A ':' is replaced by a '/'.
+ */
+void hfs_asc2mac(struct super_block *sb, struct hfs_name *out, const struct qstr *in)
+{
+	struct nls_table *nls_disk = HFS_SB(sb)->nls_disk;
+	struct nls_table *nls_io = HFS_SB(sb)->nls_io;
+	const char *src;
+	char *dst;
+	int srclen, dstlen, size;
+
+	src = in->name;
+	srclen = in->len;
+	dst = out->name;
+	dstlen = HFS_NAMELEN;
+	if (nls_io) {
+		wchar_t ch;
+
+		while (srclen > 0 && dstlen > 0) {
+			size = nls_io->char2uni(src, srclen, &ch);
+			if (size < 0) {
+				ch = '?';
+				size = 1;
+			}
+			src += size;
+			srclen -= size;
+			if (ch == ':')
+				ch = '/';
+			if (nls_disk) {
+				size = nls_disk->uni2char(ch, dst, dstlen);
+				if (size < 0) {
+					if (size == -ENAMETOOLONG)
+						goto out;
+					*dst = '?';
+					size = 1;
+				}
+				dst += size;
+				dstlen -= size;
+			} else {
+				*dst++ = ch > 0xff ? '?' : ch;
+				dstlen--;
+			}
+		}
+	} else {
+		char ch;
+
+		if (dstlen > srclen)
+			dstlen = srclen;
+		while (--dstlen >= 0)
+			*dst++ = (ch = *src++) == ':' ? '/' : ch;
+	}
+out:
+	out->len = dst - (char *)out->name;
+	dstlen = HFS_NAMELEN - out->len;
+	while (--dstlen >= 0)
+		*dst++ = 0;
+}