fs/ntfs3: Add file operations and implementation

This adds file operations and implementation

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

fs/ntfs3/dir.c

@@ -0,0 +1,596 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
+ *
+ *  directory handling functions for ntfs-based filesystems
+ *
+ */
+#include <linux/blkdev.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/iversion.h>
+#include <linux/nls.h>
+
+#include "debug.h"
+#include "ntfs.h"
+#include "ntfs_fs.h"
+
+/*
+ * Convert little endian utf16 to nls string
+ */
+int ntfs_utf16_to_nls(struct ntfs_sb_info *sbi, const struct le_str *uni,
+		      u8 *buf, int buf_len)
+{
+	int ret, uni_len, warn;
+	const __le16 *ip;
+	u8 *op;
+	struct nls_table *nls = sbi->options.nls;
+
+	static_assert(sizeof(wchar_t) == sizeof(__le16));
+
+	if (!nls) {
+		/* utf16 -> utf8 */
+		ret = utf16s_to_utf8s((wchar_t *)uni->name, uni->len,
+				      UTF16_LITTLE_ENDIAN, buf, buf_len);
+		buf[ret] = '\0';
+		return ret;
+	}
+
+	ip = uni->name;
+	op = buf;
+	uni_len = uni->len;
+	warn = 0;
+
+	while (uni_len--) {
+		u16 ec;
+		int charlen;
+		char dump[5];
+
+		if (buf_len < NLS_MAX_CHARSET_SIZE) {
+			ntfs_warn(sbi->sb,
+				  "filename was truncated while converting.");
+			break;
+		}
+
+		ec = le16_to_cpu(*ip++);
+		charlen = nls->uni2char(ec, op, buf_len);
+
+		if (charlen > 0) {
+			op += charlen;
+			buf_len -= charlen;
+			continue;
+		}
+
+		*op++ = '_';
+		buf_len -= 1;
+		if (warn)
+			continue;
+
+		warn = 1;
+		hex_byte_pack(&dump[0], ec >> 8);
+		hex_byte_pack(&dump[2], ec);
+		dump[4] = 0;
+
+		ntfs_err(sbi->sb, "failed to convert \"%s\" to %s", dump,
+			 nls->charset);
+	}
+
+	*op = '\0';
+	return op - buf;
+}
+
+// clang-format off
+#define PLANE_SIZE	0x00010000
+
+#define SURROGATE_PAIR	0x0000d800
+#define SURROGATE_LOW	0x00000400
+#define SURROGATE_BITS	0x000003ff
+// clang-format on
+
+/*
+ * modified version of put_utf16 from fs/nls/nls_base.c
+ * is sparse warnings free
+ */
+static inline void put_utf16(wchar_t *s, unsigned int c,
+			     enum utf16_endian endian)
+{
+	static_assert(sizeof(wchar_t) == sizeof(__le16));
+	static_assert(sizeof(wchar_t) == sizeof(__be16));
+
+	switch (endian) {
+	default:
+		*s = (wchar_t)c;
+		break;
+	case UTF16_LITTLE_ENDIAN:
+		*(__le16 *)s = __cpu_to_le16(c);
+		break;
+	case UTF16_BIG_ENDIAN:
+		*(__be16 *)s = __cpu_to_be16(c);
+		break;
+	}
+}
+
+/*
+ * modified version of 'utf8s_to_utf16s' allows to
+ * detect -ENAMETOOLONG without writing out of expected maximum
+ */
+static int _utf8s_to_utf16s(const u8 *s, int inlen, enum utf16_endian endian,
+			    wchar_t *pwcs, int maxout)
+{
+	u16 *op;
+	int size;
+	unicode_t u;
+
+	op = pwcs;
+	while (inlen > 0 && *s) {
+		if (*s & 0x80) {
+			size = utf8_to_utf32(s, inlen, &u);
+			if (size < 0)
+				return -EINVAL;
+			s += size;
+			inlen -= size;
+
+			if (u >= PLANE_SIZE) {
+				if (maxout < 2)
+					return -ENAMETOOLONG;
+
+				u -= PLANE_SIZE;
+				put_utf16(op++,
+					  SURROGATE_PAIR |
+						  ((u >> 10) & SURROGATE_BITS),
+					  endian);
+				put_utf16(op++,
+					  SURROGATE_PAIR | SURROGATE_LOW |
+						  (u & SURROGATE_BITS),
+					  endian);
+				maxout -= 2;
+			} else {
+				if (maxout < 1)
+					return -ENAMETOOLONG;
+
+				put_utf16(op++, u, endian);
+				maxout--;
+			}
+		} else {
+			if (maxout < 1)
+				return -ENAMETOOLONG;
+
+			put_utf16(op++, *s++, endian);
+			inlen--;
+			maxout--;
+		}
+	}
+	return op - pwcs;
+}
+
+/*
+ * Convert input string to utf16
+ *
+ * name, name_len - input name
+ * uni, max_ulen - destination memory
+ * endian - endian of target utf16 string
+ *
+ * This function is called:
+ * - to create ntfs name
+ * - to create symlink
+ *
+ * returns utf16 string length or error (if negative)
+ */
+int ntfs_nls_to_utf16(struct ntfs_sb_info *sbi, const u8 *name, u32 name_len,
+		      struct cpu_str *uni, u32 max_ulen,
+		      enum utf16_endian endian)
+{
+	int ret, slen;
+	const u8 *end;
+	struct nls_table *nls = sbi->options.nls;
+	u16 *uname = uni->name;
+
+	static_assert(sizeof(wchar_t) == sizeof(u16));
+
+	if (!nls) {
+		/* utf8 -> utf16 */
+		ret = _utf8s_to_utf16s(name, name_len, endian, uname, max_ulen);
+		uni->len = ret;
+		return ret;
+	}
+
+	for (ret = 0, end = name + name_len; name < end; ret++, name += slen) {
+		if (ret >= max_ulen)
+			return -ENAMETOOLONG;
+
+		slen = nls->char2uni(name, end - name, uname + ret);
+		if (!slen)
+			return -EINVAL;
+		if (slen < 0)
+			return slen;
+	}
+
+#ifdef __BIG_ENDIAN
+	if (endian == UTF16_LITTLE_ENDIAN) {
+		int i = ret;
+
+		while (i--) {
+			__cpu_to_le16s(uname);
+			uname++;
+		}
+	}
+#else
+	if (endian == UTF16_BIG_ENDIAN) {
+		int i = ret;
+
+		while (i--) {
+			__cpu_to_be16s(uname);
+			uname++;
+		}
+	}
+#endif
+
+	uni->len = ret;
+	return ret;
+}
+
+/* helper function */
+struct inode *dir_search_u(struct inode *dir, const struct cpu_str *uni,
+			   struct ntfs_fnd *fnd)
+{
+	int err = 0;
+	struct super_block *sb = dir->i_sb;
+	struct ntfs_sb_info *sbi = sb->s_fs_info;
+	struct ntfs_inode *ni = ntfs_i(dir);
+	struct NTFS_DE *e;
+	int diff;
+	struct inode *inode = NULL;
+	struct ntfs_fnd *fnd_a = NULL;
+
+	if (!fnd) {
+		fnd_a = fnd_get();
+		if (!fnd_a) {
+			err = -ENOMEM;
+			goto out;
+		}
+		fnd = fnd_a;
+	}
+
+	err = indx_find(&ni->dir, ni, NULL, uni, 0, sbi, &diff, &e, fnd);
+
+	if (err)
+		goto out;
+
+	if (diff) {
+		err = -ENOENT;
+		goto out;
+	}
+
+	inode = ntfs_iget5(sb, &e->ref, uni);
+	if (!IS_ERR(inode) && is_bad_inode(inode)) {
+		iput(inode);
+		err = -EINVAL;
+	}
+out:
+	fnd_put(fnd_a);
+
+	return err == -ENOENT ? NULL : err ? ERR_PTR(err) : inode;
+}
+
+static inline int ntfs_filldir(struct ntfs_sb_info *sbi, struct ntfs_inode *ni,
+			       const struct NTFS_DE *e, u8 *name,
+			       struct dir_context *ctx)
+{
+	const struct ATTR_FILE_NAME *fname;
+	unsigned long ino;
+	int name_len;
+	u32 dt_type;
+
+	fname = Add2Ptr(e, sizeof(struct NTFS_DE));
+
+	if (fname->type == FILE_NAME_DOS)
+		return 0;
+
+	if (!mi_is_ref(&ni->mi, &fname->home))
+		return 0;
+
+	ino = ino_get(&e->ref);
+
+	if (ino == MFT_REC_ROOT)
+		return 0;
+
+	/* Skip meta files ( unless option to show metafiles is set ) */
+	if (!sbi->options.showmeta && ntfs_is_meta_file(sbi, ino))
+		return 0;
+
+	if (sbi->options.nohidden && (fname->dup.fa & FILE_ATTRIBUTE_HIDDEN))
+		return 0;
+
+	name_len = ntfs_utf16_to_nls(sbi, (struct le_str *)&fname->name_len,
+				     name, PATH_MAX);
+	if (name_len <= 0) {
+		ntfs_warn(sbi->sb, "failed to convert name for inode %lx.",
+			  ino);
+		return 0;
+	}
+
+	dt_type = (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY) ? DT_DIR : DT_REG;
+
+	return !dir_emit(ctx, (s8 *)name, name_len, ino, dt_type);
+}
+
+/*
+ * ntfs_read_hdr
+ *
+ * helper function 'ntfs_readdir'
+ */
+static int ntfs_read_hdr(struct ntfs_sb_info *sbi, struct ntfs_inode *ni,
+			 const struct INDEX_HDR *hdr, u64 vbo, u64 pos,
+			 u8 *name, struct dir_context *ctx)
+{
+	int err;
+	const struct NTFS_DE *e;
+	u32 e_size;
+	u32 end = le32_to_cpu(hdr->used);
+	u32 off = le32_to_cpu(hdr->de_off);
+
+	for (;; off += e_size) {
+		if (off + sizeof(struct NTFS_DE) > end)
+			return -1;
+
+		e = Add2Ptr(hdr, off);
+		e_size = le16_to_cpu(e->size);
+		if (e_size < sizeof(struct NTFS_DE) || off + e_size > end)
+			return -1;
+
+		if (de_is_last(e))
+			return 0;
+
+		/* Skip already enumerated*/
+		if (vbo + off < pos)
+			continue;
+
+		if (le16_to_cpu(e->key_size) < SIZEOF_ATTRIBUTE_FILENAME)
+			return -1;
+
+		ctx->pos = vbo + off;
+
+		/* Submit the name to the filldir callback. */
+		err = ntfs_filldir(sbi, ni, e, name, ctx);
+		if (err)
+			return err;
+	}
+}
+
+/*
+ * file_operations::iterate_shared
+ *
+ * Use non sorted enumeration.
+ * We have an example of broken volume where sorted enumeration
+ * counts each name twice
+ */
+static int ntfs_readdir(struct file *file, struct dir_context *ctx)
+{
+	const struct INDEX_ROOT *root;
+	u64 vbo;
+	size_t bit;
+	loff_t eod;
+	int err = 0;
+	struct inode *dir = file_inode(file);
+	struct ntfs_inode *ni = ntfs_i(dir);
+	struct super_block *sb = dir->i_sb;
+	struct ntfs_sb_info *sbi = sb->s_fs_info;
+	loff_t i_size = i_size_read(dir);
+	u32 pos = ctx->pos;
+	u8 *name = NULL;
+	struct indx_node *node = NULL;
+	u8 index_bits = ni->dir.index_bits;
+
+	/* name is a buffer of PATH_MAX length */
+	static_assert(NTFS_NAME_LEN * 4 < PATH_MAX);
+
+	eod = i_size + sbi->record_size;
+
+	if (pos >= eod)
+		return 0;
+
+	if (!dir_emit_dots(file, ctx))
+		return 0;
+
+	/* allocate PATH_MAX bytes */
+	name = __getname();
+	if (!name)
+		return -ENOMEM;
+
+	if (!ni->mi_loaded && ni->attr_list.size) {
+		/*
+		 * directory inode is locked for read
+		 * load all subrecords to avoid 'write' access to 'ni' during
+		 * directory reading
+		 */
+		ni_lock(ni);
+		if (!ni->mi_loaded && ni->attr_list.size) {
+			err = ni_load_all_mi(ni);
+			if (!err)
+				ni->mi_loaded = true;
+		}
+		ni_unlock(ni);
+		if (err)
+			goto out;
+	}
+
+	root = indx_get_root(&ni->dir, ni, NULL, NULL);
+	if (!root) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (pos >= sbi->record_size) {
+		bit = (pos - sbi->record_size) >> index_bits;
+	} else {
+		err = ntfs_read_hdr(sbi, ni, &root->ihdr, 0, pos, name, ctx);
+		if (err)
+			goto out;
+		bit = 0;
+	}
+
+	if (!i_size) {
+		ctx->pos = eod;
+		goto out;
+	}
+
+	for (;;) {
+		vbo = (u64)bit << index_bits;
+		if (vbo >= i_size) {
+			ctx->pos = eod;
+			goto out;
+		}
+
+		err = indx_used_bit(&ni->dir, ni, &bit);
+		if (err)
+			goto out;
+
+		if (bit == MINUS_ONE_T) {
+			ctx->pos = eod;
+			goto out;
+		}
+
+		vbo = (u64)bit << index_bits;
+		if (vbo >= i_size) {
+			ntfs_inode_err(dir, "Looks like your dir is corrupt");
+			err = -EINVAL;
+			goto out;
+		}
+
+		err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits,
+				&node);
+		if (err)
+			goto out;
+
+		err = ntfs_read_hdr(sbi, ni, &node->index->ihdr,
+				    vbo + sbi->record_size, pos, name, ctx);
+		if (err)
+			goto out;
+
+		bit += 1;
+	}
+
+out:
+
+	__putname(name);
+	put_indx_node(node);
+
+	if (err == -ENOENT) {
+		err = 0;
+		ctx->pos = pos;
+	}
+
+	return err;
+}
+
+static int ntfs_dir_count(struct inode *dir, bool *is_empty, size_t *dirs,
+			  size_t *files)
+{
+	int err = 0;
+	struct ntfs_inode *ni = ntfs_i(dir);
+	struct NTFS_DE *e = NULL;
+	struct INDEX_ROOT *root;
+	struct INDEX_HDR *hdr;
+	const struct ATTR_FILE_NAME *fname;
+	u32 e_size, off, end;
+	u64 vbo = 0;
+	size_t drs = 0, fles = 0, bit = 0;
+	loff_t i_size = ni->vfs_inode.i_size;
+	struct indx_node *node = NULL;
+	u8 index_bits = ni->dir.index_bits;
+
+	if (is_empty)
+		*is_empty = true;
+
+	root = indx_get_root(&ni->dir, ni, NULL, NULL);
+	if (!root)
+		return -EINVAL;
+
+	hdr = &root->ihdr;
+
+	for (;;) {
+		end = le32_to_cpu(hdr->used);
+		off = le32_to_cpu(hdr->de_off);
+
+		for (; off + sizeof(struct NTFS_DE) <= end; off += e_size) {
+			e = Add2Ptr(hdr, off);
+			e_size = le16_to_cpu(e->size);
+			if (e_size < sizeof(struct NTFS_DE) ||
+			    off + e_size > end)
+				break;
+
+			if (de_is_last(e))
+				break;
+
+			fname = de_get_fname(e);
+			if (!fname)
+				continue;
+
+			if (fname->type == FILE_NAME_DOS)
+				continue;
+
+			if (is_empty) {
+				*is_empty = false;
+				if (!dirs && !files)
+					goto out;
+			}
+
+			if (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY)
+				drs += 1;
+			else
+				fles += 1;
+		}
+
+		if (vbo >= i_size)
+			goto out;
+
+		err = indx_used_bit(&ni->dir, ni, &bit);
+		if (err)
+			goto out;
+
+		if (bit == MINUS_ONE_T)
+			goto out;
+
+		vbo = (u64)bit << index_bits;
+		if (vbo >= i_size)
+			goto out;
+
+		err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits,
+				&node);
+		if (err)
+			goto out;
+
+		hdr = &node->index->ihdr;
+		bit += 1;
+		vbo = (u64)bit << ni->dir.idx2vbn_bits;
+	}
+
+out:
+	put_indx_node(node);
+	if (dirs)
+		*dirs = drs;
+	if (files)
+		*files = fles;
+
+	return err;
+}
+
+bool dir_is_empty(struct inode *dir)
+{
+	bool is_empty = false;
+
+	ntfs_dir_count(dir, &is_empty, NULL, NULL);
+
+	return is_empty;
+}
+
+// clang-format off
+const struct file_operations ntfs_dir_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= generic_read_dir,
+	.iterate_shared	= ntfs_readdir,
+	.fsync		= generic_file_fsync,
+	.open		= ntfs_file_open,
+};
+// clang-format on

fs/ntfs3/namei.c

@@ -0,0 +1,539 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
+ *
+ */
+
+#include <linux/blkdev.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/iversion.h>
+#include <linux/namei.h>
+#include <linux/nls.h>
+
+#include "debug.h"
+#include "ntfs.h"
+#include "ntfs_fs.h"
+
+/*
+ * fill_name_de
+ *
+ * formats NTFS_DE in 'buf'
+ */
+int fill_name_de(struct ntfs_sb_info *sbi, void *buf, const struct qstr *name,
+		 const struct cpu_str *uni)
+{
+	int err;
+	struct NTFS_DE *e = buf;
+	u16 data_size;
+	struct ATTR_FILE_NAME *fname = (struct ATTR_FILE_NAME *)(e + 1);
+
+#ifndef CONFIG_NTFS3_64BIT_CLUSTER
+	e->ref.high = fname->home.high = 0;
+#endif
+	if (uni) {
+#ifdef __BIG_ENDIAN
+		int ulen = uni->len;
+		__le16 *uname = fname->name;
+		const u16 *name_cpu = uni->name;
+
+		while (ulen--)
+			*uname++ = cpu_to_le16(*name_cpu++);
+#else
+		memcpy(fname->name, uni->name, uni->len * sizeof(u16));
+#endif
+		fname->name_len = uni->len;
+
+	} else {
+		/* Convert input string to unicode */
+		err = ntfs_nls_to_utf16(sbi, name->name, name->len,
+					(struct cpu_str *)&fname->name_len,
+					NTFS_NAME_LEN, UTF16_LITTLE_ENDIAN);
+		if (err < 0)
+			return err;
+	}
+
+	fname->type = FILE_NAME_POSIX;
+	data_size = fname_full_size(fname);
+
+	e->size = cpu_to_le16(QuadAlign(data_size) + sizeof(struct NTFS_DE));
+	e->key_size = cpu_to_le16(data_size);
+	e->flags = 0;
+	e->res = 0;
+
+	return 0;
+}
+
+/*
+ * ntfs_lookup
+ *
+ * inode_operations::lookup
+ */
+static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
+				  u32 flags)
+{
+	struct ntfs_inode *ni = ntfs_i(dir);
+	struct cpu_str *uni = __getname();
+	struct inode *inode;
+	int err;
+
+	if (!uni)
+		inode = ERR_PTR(-ENOMEM);
+	else {
+		err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,
+					dentry->d_name.len, uni, NTFS_NAME_LEN,
+					UTF16_HOST_ENDIAN);
+		if (err < 0)
+			inode = ERR_PTR(err);
+		else {
+			ni_lock(ni);
+			inode = dir_search_u(dir, uni, NULL);
+			ni_unlock(ni);
+		}
+		__putname(uni);
+	}
+
+	return d_splice_alias(inode, dentry);
+}
+
+/*
+ * ntfs_create
+ *
+ * inode_operations::create
+ */
+static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
+		       struct dentry *dentry, umode_t mode, bool excl)
+{
+	struct ntfs_inode *ni = ntfs_i(dir);
+	struct inode *inode;
+
+	ni_lock_dir(ni);
+
+	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFREG | mode,
+				  0, NULL, 0, NULL);
+
+	ni_unlock(ni);
+
+	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
+}
+
+/*
+ * ntfs_mknod
+ *
+ * inode_operations::mknod
+ */
+static int ntfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
+		      struct dentry *dentry, umode_t mode, dev_t rdev)
+{
+	struct ntfs_inode *ni = ntfs_i(dir);
+	struct inode *inode;
+
+	ni_lock_dir(ni);
+
+	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, mode, rdev,
+				  NULL, 0, NULL);
+
+	ni_unlock(ni);
+
+	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
+}
+
+/*
+ * ntfs_link
+ *
+ * inode_operations::link
+ */
+static int ntfs_link(struct dentry *ode, struct inode *dir, struct dentry *de)
+{
+	int err;
+	struct inode *inode = d_inode(ode);
+	struct ntfs_inode *ni = ntfs_i(inode);
+
+	if (S_ISDIR(inode->i_mode))
+		return -EPERM;
+
+	if (inode->i_nlink >= NTFS_LINK_MAX)
+		return -EMLINK;
+
+	ni_lock_dir(ntfs_i(dir));
+	if (inode != dir)
+		ni_lock(ni);
+
+	dir->i_ctime = dir->i_mtime = inode->i_ctime = current_time(inode);
+	inc_nlink(inode);
+	ihold(inode);
+
+	err = ntfs_link_inode(inode, de);
+	if (!err) {
+		mark_inode_dirty(inode);
+		mark_inode_dirty(dir);
+		d_instantiate(de, inode);
+	} else {
+		drop_nlink(inode);
+		iput(inode);
+	}
+
+	if (inode != dir)
+		ni_unlock(ni);
+	ni_unlock(ntfs_i(dir));
+
+	return err;
+}
+
+/*
+ * ntfs_unlink
+ *
+ * inode_operations::unlink
+ */
+static int ntfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct ntfs_inode *ni = ntfs_i(dir);
+	int err;
+
+	ni_lock_dir(ni);
+
+	err = ntfs_unlink_inode(dir, dentry);
+
+	ni_unlock(ni);
+
+	return err;
+}
+
+/*
+ * ntfs_symlink
+ *
+ * inode_operations::symlink
+ */
+static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
+			struct dentry *dentry, const char *symname)
+{
+	u32 size = strlen(symname);
+	struct inode *inode;
+	struct ntfs_inode *ni = ntfs_i(dir);
+
+	ni_lock_dir(ni);
+
+	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFLNK | 0777,
+				  0, symname, size, NULL);
+
+	ni_unlock(ni);
+
+	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
+}
+
+/*
+ * ntfs_mkdir
+ *
+ * inode_operations::mkdir
+ */
+static int ntfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
+		      struct dentry *dentry, umode_t mode)
+{
+	struct inode *inode;
+	struct ntfs_inode *ni = ntfs_i(dir);
+
+	ni_lock_dir(ni);
+
+	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFDIR | mode,
+				  0, NULL, 0, NULL);
+
+	ni_unlock(ni);
+
+	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
+}
+
+/*
+ * ntfs_rmdir
+ *
+ * inode_operations::rm_dir
+ */
+static int ntfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct ntfs_inode *ni = ntfs_i(dir);
+	int err;
+
+	ni_lock_dir(ni);
+
+	err = ntfs_unlink_inode(dir, dentry);
+
+	ni_unlock(ni);
+
+	return err;
+}
+
+/*
+ * ntfs_rename
+ *
+ * inode_operations::rename
+ */
+static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
+		       struct dentry *old_dentry, struct inode *new_dir,
+		       struct dentry *new_dentry, u32 flags)
+{
+	int err;
+	struct super_block *sb = old_dir->i_sb;
+	struct ntfs_sb_info *sbi = sb->s_fs_info;
+	struct ntfs_inode *old_dir_ni = ntfs_i(old_dir);
+	struct ntfs_inode *new_dir_ni = ntfs_i(new_dir);
+	struct ntfs_inode *old_ni;
+	struct ATTR_FILE_NAME *old_name, *new_name, *fname;
+	u8 name_type;
+	bool is_same;
+	struct inode *old_inode, *new_inode;
+	struct NTFS_DE *old_de, *new_de;
+	struct ATTRIB *attr;
+	struct ATTR_LIST_ENTRY *le;
+	u16 new_de_key_size;
+
+	static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + SIZEOF_RESIDENT < 1024);
+	static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + sizeof(struct NTFS_DE) <
+		      1024);
+	static_assert(PATH_MAX >= 4 * 1024);
+
+	if (flags & ~RENAME_NOREPLACE)
+		return -EINVAL;
+
+	old_inode = d_inode(old_dentry);
+	new_inode = d_inode(new_dentry);
+
+	old_ni = ntfs_i(old_inode);
+
+	is_same = old_dentry->d_name.len == new_dentry->d_name.len &&
+		  !memcmp(old_dentry->d_name.name, new_dentry->d_name.name,
+			  old_dentry->d_name.len);
+
+	if (is_same && old_dir == new_dir) {
+		/* Nothing to do */
+		err = 0;
+		goto out;
+	}
+
+	if (ntfs_is_meta_file(sbi, old_inode->i_ino)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (new_inode) {
+		/*target name exists. unlink it*/
+		dget(new_dentry);
+		ni_lock_dir(new_dir_ni);
+		err = ntfs_unlink_inode(new_dir, new_dentry);
+		ni_unlock(new_dir_ni);
+		dput(new_dentry);
+		if (err)
+			goto out;
+	}
+
+	/* allocate PATH_MAX bytes */
+	old_de = __getname();
+	if (!old_de) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = fill_name_de(sbi, old_de, &old_dentry->d_name, NULL);
+	if (err < 0)
+		goto out1;
+
+	old_name = (struct ATTR_FILE_NAME *)(old_de + 1);
+
+	if (is_same) {
+		new_de = old_de;
+	} else {
+		new_de = Add2Ptr(old_de, 1024);
+		err = fill_name_de(sbi, new_de, &new_dentry->d_name, NULL);
+		if (err < 0)
+			goto out1;
+	}
+
+	ni_lock_dir(old_dir_ni);
+	ni_lock(old_ni);
+
+	mi_get_ref(&old_dir_ni->mi, &old_name->home);
+
+	/*get pointer to file_name in mft*/
+	fname = ni_fname_name(old_ni, (struct cpu_str *)&old_name->name_len,
+			      &old_name->home, &le);
+	if (!fname) {
+		err = -EINVAL;
+		goto out2;
+	}
+
+	/* Copy fname info from record into new fname */
+	new_name = (struct ATTR_FILE_NAME *)(new_de + 1);
+	memcpy(&new_name->dup, &fname->dup, sizeof(fname->dup));
+
+	name_type = paired_name(fname->type);
+
+	/* remove first name from directory */
+	err = indx_delete_entry(&old_dir_ni->dir, old_dir_ni, old_de + 1,
+				le16_to_cpu(old_de->key_size), sbi);
+	if (err)
+		goto out3;
+
+	/* remove first name from mft */
+	err = ni_remove_attr_le(old_ni, attr_from_name(fname), le);
+	if (err)
+		goto out4;
+
+	le16_add_cpu(&old_ni->mi.mrec->hard_links, -1);
+	old_ni->mi.dirty = true;
+
+	if (name_type != FILE_NAME_POSIX) {
+		/* get paired name */
+		fname = ni_fname_type(old_ni, name_type, &le);
+		if (fname) {
+			/* remove second name from directory */
+			err = indx_delete_entry(&old_dir_ni->dir, old_dir_ni,
+						fname, fname_full_size(fname),
+						sbi);
+			if (err)
+				goto out5;
+
+			/* remove second name from mft */
+			err = ni_remove_attr_le(old_ni, attr_from_name(fname),
+						le);
+			if (err)
+				goto out6;
+
+			le16_add_cpu(&old_ni->mi.mrec->hard_links, -1);
+			old_ni->mi.dirty = true;
+		}
+	}
+
+	/* Add new name */
+	mi_get_ref(&old_ni->mi, &new_de->ref);
+	mi_get_ref(&ntfs_i(new_dir)->mi, &new_name->home);
+
+	new_de_key_size = le16_to_cpu(new_de->key_size);
+
+	/* insert new name in mft */
+	err = ni_insert_resident(old_ni, new_de_key_size, ATTR_NAME, NULL, 0,
+				 &attr, NULL);
+	if (err)
+		goto out7;
+
+	attr->res.flags = RESIDENT_FLAG_INDEXED;
+
+	memcpy(Add2Ptr(attr, SIZEOF_RESIDENT), new_name, new_de_key_size);
+
+	le16_add_cpu(&old_ni->mi.mrec->hard_links, 1);
+	old_ni->mi.dirty = true;
+
+	/* insert new name in directory */
+	err = indx_insert_entry(&new_dir_ni->dir, new_dir_ni, new_de, sbi,
+				NULL);
+	if (err)
+		goto out8;
+
+	if (IS_DIRSYNC(new_dir))
+		err = ntfs_sync_inode(old_inode);
+	else
+		mark_inode_dirty(old_inode);
+
+	old_dir->i_ctime = old_dir->i_mtime = current_time(old_dir);
+	if (IS_DIRSYNC(old_dir))
+		(void)ntfs_sync_inode(old_dir);
+	else
+		mark_inode_dirty(old_dir);
+
+	if (old_dir != new_dir) {
+		new_dir->i_mtime = new_dir->i_ctime = old_dir->i_ctime;
+		mark_inode_dirty(new_dir);
+	}
+
+	if (old_inode) {
+		old_inode->i_ctime = old_dir->i_ctime;
+		mark_inode_dirty(old_inode);
+	}
+
+	err = 0;
+	/* normal way */
+	goto out2;
+
+out8:
+	/* undo
+	 * ni_insert_resident(old_ni, new_de_key_size, ATTR_NAME, NULL, 0,
+	 *			 &attr, NULL);
+	 */
+	mi_remove_attr(&old_ni->mi, attr);
+out7:
+	/* undo
+	 * ni_remove_attr_le(old_ni, attr_from_name(fname), le);
+	 */
+out6:
+	/* undo
+	 * indx_delete_entry(&old_dir_ni->dir, old_dir_ni,
+	 *					fname, fname_full_size(fname),
+	 *					sbi);
+	 */
+out5:
+	/* undo
+	 * ni_remove_attr_le(old_ni, attr_from_name(fname), le);
+	 */
+out4:
+	/* undo:
+	 * indx_delete_entry(&old_dir_ni->dir, old_dir_ni, old_de + 1,
+	 *			old_de->key_size, NULL);
+	 */
+out3:
+out2:
+	ni_unlock(old_ni);
+	ni_unlock(old_dir_ni);
+out1:
+	__putname(old_de);
+out:
+	return err;
+}
+
+struct dentry *ntfs3_get_parent(struct dentry *child)
+{
+	struct inode *inode = d_inode(child);
+	struct ntfs_inode *ni = ntfs_i(inode);
+
+	struct ATTR_LIST_ENTRY *le = NULL;
+	struct ATTRIB *attr = NULL;
+	struct ATTR_FILE_NAME *fname;
+
+	while ((attr = ni_find_attr(ni, attr, &le, ATTR_NAME, NULL, 0, NULL,
+				    NULL))) {
+		fname = resident_data_ex(attr, SIZEOF_ATTRIBUTE_FILENAME);
+		if (!fname)
+			continue;
+
+		return d_obtain_alias(
+			ntfs_iget5(inode->i_sb, &fname->home, NULL));
+	}
+
+	return ERR_PTR(-ENOENT);
+}
+
+// clang-format off
+const struct inode_operations ntfs_dir_inode_operations = {
+	.lookup		= ntfs_lookup,
+	.create		= ntfs_create,
+	.link		= ntfs_link,
+	.unlink		= ntfs_unlink,
+	.symlink	= ntfs_symlink,
+	.mkdir		= ntfs_mkdir,
+	.rmdir		= ntfs_rmdir,
+	.mknod		= ntfs_mknod,
+	.rename		= ntfs_rename,
+	.permission	= ntfs_permission,
+	.get_acl	= ntfs_get_acl,
+	.set_acl	= ntfs_set_acl,
+	.setattr	= ntfs3_setattr,
+	.getattr	= ntfs_getattr,
+	.listxattr	= ntfs_listxattr,
+	.fiemap		= ntfs_fiemap,
+};
+
+const struct inode_operations ntfs_special_inode_operations = {
+	.setattr	= ntfs3_setattr,
+	.getattr	= ntfs_getattr,
+	.listxattr	= ntfs_listxattr,
+	.get_acl	= ntfs_get_acl,
+	.set_acl	= ntfs_set_acl,
+};
+// clang-format on

fs/ntfs3/record.c

@@ -0,0 +1,609 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
+ *
+ */
+
+#include <linux/blkdev.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/nls.h>
+
+#include "debug.h"
+#include "ntfs.h"
+#include "ntfs_fs.h"
+
+static inline int compare_attr(const struct ATTRIB *left, enum ATTR_TYPE type,
+			       const __le16 *name, u8 name_len,
+			       const u16 *upcase)
+{
+	/* First, compare the type codes: */
+	int diff = le32_to_cpu(left->type) - le32_to_cpu(type);
+
+	if (diff)
+		return diff;
+
+	/*
+	 * They have the same type code, so we have to compare the names.
+	 */
+	return ntfs_cmp_names(attr_name(left), left->name_len, name, name_len,
+			      upcase, true);
+}
+
+/*
+ * mi_new_attt_id
+ *
+ * returns unused attribute id that is less than mrec->next_attr_id
+ */
+static __le16 mi_new_attt_id(struct mft_inode *mi)
+{
+	u16 free_id, max_id, t16;
+	struct MFT_REC *rec = mi->mrec;
+	struct ATTRIB *attr;
+	__le16 id;
+
+	id = rec->next_attr_id;
+	free_id = le16_to_cpu(id);
+	if (free_id < 0x7FFF) {
+		rec->next_attr_id = cpu_to_le16(free_id + 1);
+		return id;
+	}
+
+	/* One record can store up to 1024/24 ~= 42 attributes */
+	free_id = 0;
+	max_id = 0;
+
+	attr = NULL;
+
+	for (;;) {
+		attr = mi_enum_attr(mi, attr);
+		if (!attr) {
+			rec->next_attr_id = cpu_to_le16(max_id + 1);
+			mi->dirty = true;
+			return cpu_to_le16(free_id);
+		}
+
+		t16 = le16_to_cpu(attr->id);
+		if (t16 == free_id) {
+			free_id += 1;
+			attr = NULL;
+		} else if (max_id < t16)
+			max_id = t16;
+	}
+}
+
+int mi_get(struct ntfs_sb_info *sbi, CLST rno, struct mft_inode **mi)
+{
+	int err;
+	struct mft_inode *m = ntfs_zalloc(sizeof(struct mft_inode));
+
+	if (!m)
+		return -ENOMEM;
+
+	err = mi_init(m, sbi, rno);
+	if (err) {
+		ntfs_free(m);
+		return err;
+	}
+
+	err = mi_read(m, false);
+	if (err) {
+		mi_put(m);
+		return err;
+	}
+
+	*mi = m;
+	return 0;
+}
+
+void mi_put(struct mft_inode *mi)
+{
+	mi_clear(mi);
+	ntfs_free(mi);
+}
+
+int mi_init(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno)
+{
+	mi->sbi = sbi;
+	mi->rno = rno;
+	mi->mrec = ntfs_malloc(sbi->record_size);
+	if (!mi->mrec)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/*
+ * mi_read
+ *
+ * reads MFT data
+ */
+int mi_read(struct mft_inode *mi, bool is_mft)
+{
+	int err;
+	struct MFT_REC *rec = mi->mrec;
+	struct ntfs_sb_info *sbi = mi->sbi;
+	u32 bpr = sbi->record_size;
+	u64 vbo = (u64)mi->rno << sbi->record_bits;
+	struct ntfs_inode *mft_ni = sbi->mft.ni;
+	struct runs_tree *run = mft_ni ? &mft_ni->file.run : NULL;
+	struct rw_semaphore *rw_lock = NULL;
+
+	if (is_mounted(sbi)) {
+		if (!is_mft) {
+			rw_lock = &mft_ni->file.run_lock;
+			down_read(rw_lock);
+		}
+	}
+
+	err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
+	if (rw_lock)
+		up_read(rw_lock);
+	if (!err)
+		goto ok;
+
+	if (err == -E_NTFS_FIXUP) {
+		mi->dirty = true;
+		goto ok;
+	}
+
+	if (err != -ENOENT)
+		goto out;
+
+	if (rw_lock) {
+		ni_lock(mft_ni);
+		down_write(rw_lock);
+	}
+	err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, &mft_ni->file.run,
+				 vbo >> sbi->cluster_bits);
+	if (rw_lock) {
+		up_write(rw_lock);
+		ni_unlock(mft_ni);
+	}
+	if (err)
+		goto out;
+
+	if (rw_lock)
+		down_read(rw_lock);
+	err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
+	if (rw_lock)
+		up_read(rw_lock);
+
+	if (err == -E_NTFS_FIXUP) {
+		mi->dirty = true;
+		goto ok;
+	}
+	if (err)
+		goto out;
+
+ok:
+	/* check field 'total' only here */
+	if (le32_to_cpu(rec->total) != bpr) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	return 0;
+
+out:
+	return err;
+}
+
+struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
+{
+	const struct MFT_REC *rec = mi->mrec;
+	u32 used = le32_to_cpu(rec->used);
+	u32 t32, off, asize;
+	u16 t16;
+
+	if (!attr) {
+		u32 total = le32_to_cpu(rec->total);
+
+		off = le16_to_cpu(rec->attr_off);
+
+		if (used > total)
+			return NULL;
+
+		if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 ||
+		    !IsDwordAligned(off)) {
+			return NULL;
+		}
+
+		/* Skip non-resident records */
+		if (!is_rec_inuse(rec))
+			return NULL;
+
+		attr = Add2Ptr(rec, off);
+	} else {
+		/* Check if input attr inside record */
+		off = PtrOffset(rec, attr);
+		if (off >= used)
+			return NULL;
+
+		asize = le32_to_cpu(attr->size);
+		if (asize < SIZEOF_RESIDENT) {
+			/* Impossible 'cause we should not return such attribute */
+			return NULL;
+		}
+
+		attr = Add2Ptr(attr, asize);
+		off += asize;
+	}
+
+	asize = le32_to_cpu(attr->size);
+
+	/* Can we use the first field (attr->type) */
+	if (off + 8 > used) {
+		static_assert(QuadAlign(sizeof(enum ATTR_TYPE)) == 8);
+		return NULL;
+	}
+
+	if (attr->type == ATTR_END) {
+		/* end of enumeration */
+		return NULL;
+	}
+
+	/* 0x100 is last known attribute for now*/
+	t32 = le32_to_cpu(attr->type);
+	if ((t32 & 0xf) || (t32 > 0x100))
+		return NULL;
+
+	/* Check boundary */
+	if (off + asize > used)
+		return NULL;
+
+	/* Check size of attribute */
+	if (!attr->non_res) {
+		if (asize < SIZEOF_RESIDENT)
+			return NULL;
+
+		t16 = le16_to_cpu(attr->res.data_off);
+
+		if (t16 > asize)
+			return NULL;
+
+		t32 = le32_to_cpu(attr->res.data_size);
+		if (t16 + t32 > asize)
+			return NULL;
+
+		return attr;
+	}
+
+	/* Check some nonresident fields */
+	if (attr->name_len &&
+	    le16_to_cpu(attr->name_off) + sizeof(short) * attr->name_len >
+		    le16_to_cpu(attr->nres.run_off)) {
+		return NULL;
+	}
+
+	if (attr->nres.svcn || !is_attr_ext(attr)) {
+		if (asize + 8 < SIZEOF_NONRESIDENT)
+			return NULL;
+
+		if (attr->nres.c_unit)
+			return NULL;
+	} else if (asize + 8 < SIZEOF_NONRESIDENT_EX)
+		return NULL;
+
+	return attr;
+}
+
+/*
+ * mi_find_attr
+ *
+ * finds the attribute by type and name and id
+ */
+struct ATTRIB *mi_find_attr(struct mft_inode *mi, struct ATTRIB *attr,
+			    enum ATTR_TYPE type, const __le16 *name,
+			    size_t name_len, const __le16 *id)
+{
+	u32 type_in = le32_to_cpu(type);
+	u32 atype;
+
+next_attr:
+	attr = mi_enum_attr(mi, attr);
+	if (!attr)
+		return NULL;
+
+	atype = le32_to_cpu(attr->type);
+	if (atype > type_in)
+		return NULL;
+
+	if (atype < type_in)
+		goto next_attr;
+
+	if (attr->name_len != name_len)
+		goto next_attr;
+
+	if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short)))
+		goto next_attr;
+
+	if (id && *id != attr->id)
+		goto next_attr;
+
+	return attr;
+}
+
+int mi_write(struct mft_inode *mi, int wait)
+{
+	struct MFT_REC *rec;
+	int err;
+	struct ntfs_sb_info *sbi;
+
+	if (!mi->dirty)
+		return 0;
+
+	sbi = mi->sbi;
+	rec = mi->mrec;
+
+	err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait);
+	if (err)
+		return err;
+
+	if (mi->rno < sbi->mft.recs_mirr)
+		sbi->flags |= NTFS_FLAGS_MFTMIRR;
+
+	mi->dirty = false;
+
+	return 0;
+}
+
+int mi_format_new(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno,
+		  __le16 flags, bool is_mft)
+{
+	int err;
+	u16 seq = 1;
+	struct MFT_REC *rec;
+	u64 vbo = (u64)rno << sbi->record_bits;
+
+	err = mi_init(mi, sbi, rno);
+	if (err)
+		return err;
+
+	rec = mi->mrec;
+
+	if (rno == MFT_REC_MFT) {
+		;
+	} else if (rno < MFT_REC_FREE) {
+		seq = rno;
+	} else if (rno >= sbi->mft.used) {
+		;
+	} else if (mi_read(mi, is_mft)) {
+		;
+	} else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) {
+		/* Record is reused. Update its sequence number */
+		seq = le16_to_cpu(rec->seq) + 1;
+		if (!seq)
+			seq = 1;
+	}
+
+	memcpy(rec, sbi->new_rec, sbi->record_size);
+
+	rec->seq = cpu_to_le16(seq);
+	rec->flags = RECORD_FLAG_IN_USE | flags;
+
+	mi->dirty = true;
+
+	if (!mi->nb.nbufs) {
+		struct ntfs_inode *ni = sbi->mft.ni;
+		bool lock = false;
+
+		if (is_mounted(sbi) && !is_mft) {
+			down_read(&ni->file.run_lock);
+			lock = true;
+		}
+
+		err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size,
+				  &mi->nb);
+		if (lock)
+			up_read(&ni->file.run_lock);
+	}
+
+	return err;
+}
+
+/*
+ * mi_mark_free
+ *
+ * marks record as unused and marks it as free in bitmap
+ */
+void mi_mark_free(struct mft_inode *mi)
+{
+	CLST rno = mi->rno;
+	struct ntfs_sb_info *sbi = mi->sbi;
+
+	if (rno >= MFT_REC_RESERVED && rno < MFT_REC_FREE) {
+		ntfs_clear_mft_tail(sbi, rno, rno + 1);
+		mi->dirty = false;
+		return;
+	}
+
+	if (mi->mrec) {
+		clear_rec_inuse(mi->mrec);
+		mi->dirty = true;
+		mi_write(mi, 0);
+	}
+	ntfs_mark_rec_free(sbi, rno);
+}
+
+/*
+ * mi_insert_attr
+ *
+ * reserves space for new attribute
+ * returns not full constructed attribute or NULL if not possible to create
+ */
+struct ATTRIB *mi_insert_attr(struct mft_inode *mi, enum ATTR_TYPE type,
+			      const __le16 *name, u8 name_len, u32 asize,
+			      u16 name_off)
+{
+	size_t tail;
+	struct ATTRIB *attr;
+	__le16 id;
+	struct MFT_REC *rec = mi->mrec;
+	struct ntfs_sb_info *sbi = mi->sbi;
+	u32 used = le32_to_cpu(rec->used);
+	const u16 *upcase = sbi->upcase;
+	int diff;
+
+	/* Can we insert mi attribute? */
+	if (used + asize > mi->sbi->record_size)
+		return NULL;
+
+	/*
+	 * Scan through the list of attributes to find the point
+	 * at which we should insert it.
+	 */
+	attr = NULL;
+	while ((attr = mi_enum_attr(mi, attr))) {
+		diff = compare_attr(attr, type, name, name_len, upcase);
+		if (diff > 0)
+			break;
+		if (diff < 0)
+			continue;
+
+		if (!is_attr_indexed(attr))
+			return NULL;
+		break;
+	}
+
+	if (!attr) {
+		tail = 8; /* not used, just to suppress warning */
+		attr = Add2Ptr(rec, used - 8);
+	} else {
+		tail = used - PtrOffset(rec, attr);
+	}
+
+	id = mi_new_attt_id(mi);
+
+	memmove(Add2Ptr(attr, asize), attr, tail);
+	memset(attr, 0, asize);
+
+	attr->type = type;
+	attr->size = cpu_to_le32(asize);
+	attr->name_len = name_len;
+	attr->name_off = cpu_to_le16(name_off);
+	attr->id = id;
+
+	memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short));
+	rec->used = cpu_to_le32(used + asize);
+
+	mi->dirty = true;
+
+	return attr;
+}
+
+/*
+ * mi_remove_attr
+ *
+ * removes the attribute from record
+ * NOTE: The source attr will point to next attribute
+ */
+bool mi_remove_attr(struct mft_inode *mi, struct ATTRIB *attr)
+{
+	struct MFT_REC *rec = mi->mrec;
+	u32 aoff = PtrOffset(rec, attr);
+	u32 used = le32_to_cpu(rec->used);
+	u32 asize = le32_to_cpu(attr->size);
+
+	if (aoff + asize > used)
+		return false;
+
+	used -= asize;
+	memmove(attr, Add2Ptr(attr, asize), used - aoff);
+	rec->used = cpu_to_le32(used);
+	mi->dirty = true;
+
+	return true;
+}
+
+/* bytes = "new attribute size" - "old attribute size" */
+bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes)
+{
+	struct MFT_REC *rec = mi->mrec;
+	u32 aoff = PtrOffset(rec, attr);
+	u32 total, used = le32_to_cpu(rec->used);
+	u32 nsize, asize = le32_to_cpu(attr->size);
+	u32 rsize = le32_to_cpu(attr->res.data_size);
+	int tail = (int)(used - aoff - asize);
+	int dsize;
+	char *next;
+
+	if (tail < 0 || aoff >= used)
+		return false;
+
+	if (!bytes)
+		return true;
+
+	total = le32_to_cpu(rec->total);
+	next = Add2Ptr(attr, asize);
+
+	if (bytes > 0) {
+		dsize = QuadAlign(bytes);
+		if (used + dsize > total)
+			return false;
+		nsize = asize + dsize;
+		// move tail
+		memmove(next + dsize, next, tail);
+		memset(next, 0, dsize);
+		used += dsize;
+		rsize += dsize;
+	} else {
+		dsize = QuadAlign(-bytes);
+		if (dsize > asize)
+			return false;
+		nsize = asize - dsize;
+		memmove(next - dsize, next, tail);
+		used -= dsize;
+		rsize -= dsize;
+	}
+
+	rec->used = cpu_to_le32(used);
+	attr->size = cpu_to_le32(nsize);
+	if (!attr->non_res)
+		attr->res.data_size = cpu_to_le32(rsize);
+	mi->dirty = true;
+
+	return true;
+}
+
+int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr,
+		 struct runs_tree *run, CLST len)
+{
+	int err = 0;
+	struct ntfs_sb_info *sbi = mi->sbi;
+	u32 new_run_size;
+	CLST plen;
+	struct MFT_REC *rec = mi->mrec;
+	CLST svcn = le64_to_cpu(attr->nres.svcn);
+	u32 used = le32_to_cpu(rec->used);
+	u32 aoff = PtrOffset(rec, attr);
+	u32 asize = le32_to_cpu(attr->size);
+	char *next = Add2Ptr(attr, asize);
+	u16 run_off = le16_to_cpu(attr->nres.run_off);
+	u32 run_size = asize - run_off;
+	u32 tail = used - aoff - asize;
+	u32 dsize = sbi->record_size - used;
+
+	/* Make a maximum gap in current record */
+	memmove(next + dsize, next, tail);
+
+	/* Pack as much as possible */
+	err = run_pack(run, svcn, len, Add2Ptr(attr, run_off), run_size + dsize,
+		       &plen);
+	if (err < 0) {
+		memmove(next, next + dsize, tail);
+		return err;
+	}
+
+	new_run_size = QuadAlign(err);
+
+	memmove(next + new_run_size - run_size, next + dsize, tail);
+
+	attr->size = cpu_to_le32(asize + new_run_size - run_size);
+	attr->nres.evcn = cpu_to_le64(svcn + plen - 1);
+	rec->used = cpu_to_le32(used + new_run_size - run_size);
+	mi->dirty = true;
+
+	return 0;
+}