fs/ntfs3: Add initialization of super block

This adds initialization of super block

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

1 files changed, 2647 insertions, 0 deletions

diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c
new file mode 100644
index 000000000000..6aa9540ece47
--- /dev/null
+++ b/fs/ntfs3/index.c
@@ -0,0 +1,2647 @@
+// 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 const struct INDEX_NAMES {
+	const __le16 *name;
+	u8 name_len;
+} s_index_names[INDEX_MUTEX_TOTAL] = {
+	{ I30_NAME, ARRAY_SIZE(I30_NAME) }, { SII_NAME, ARRAY_SIZE(SII_NAME) },
+	{ SDH_NAME, ARRAY_SIZE(SDH_NAME) }, { SO_NAME, ARRAY_SIZE(SO_NAME) },
+	{ SQ_NAME, ARRAY_SIZE(SQ_NAME) },   { SR_NAME, ARRAY_SIZE(SR_NAME) },
+};
+
+/*
+ * compare two names in index
+ * if l1 != 0
+ *   both names are little endian on-disk ATTR_FILE_NAME structs
+ * else
+ *   key1 - cpu_str, key2 - ATTR_FILE_NAME
+ */
+static int cmp_fnames(const void *key1, size_t l1, const void *key2, size_t l2,
+		      const void *data)
+{
+	const struct ATTR_FILE_NAME *f2 = key2;
+	const struct ntfs_sb_info *sbi = data;
+	const struct ATTR_FILE_NAME *f1;
+	u16 fsize2;
+	bool both_case;
+
+	if (l2 <= offsetof(struct ATTR_FILE_NAME, name))
+		return -1;
+
+	fsize2 = fname_full_size(f2);
+	if (l2 < fsize2)
+		return -1;
+
+	both_case = f2->type != FILE_NAME_DOS /*&& !sbi->options.nocase*/;
+	if (!l1) {
+		const struct le_str *s2 = (struct le_str *)&f2->name_len;
+
+		/*
+		 * If names are equal (case insensitive)
+		 * try to compare it case sensitive
+		 */
+		return ntfs_cmp_names_cpu(key1, s2, sbi->upcase, both_case);
+	}
+
+	f1 = key1;
+	return ntfs_cmp_names(f1->name, f1->name_len, f2->name, f2->name_len,
+			      sbi->upcase, both_case);
+}
+
+/* $SII of $Secure and $Q of Quota */
+static int cmp_uint(const void *key1, size_t l1, const void *key2, size_t l2,
+		    const void *data)
+{
+	const u32 *k1 = key1;
+	const u32 *k2 = key2;
+
+	if (l2 < sizeof(u32))
+		return -1;
+
+	if (*k1 < *k2)
+		return -1;
+	if (*k1 > *k2)
+		return 1;
+	return 0;
+}
+
+/* $SDH of $Secure */
+static int cmp_sdh(const void *key1, size_t l1, const void *key2, size_t l2,
+		   const void *data)
+{
+	const struct SECURITY_KEY *k1 = key1;
+	const struct SECURITY_KEY *k2 = key2;
+	u32 t1, t2;
+
+	if (l2 < sizeof(struct SECURITY_KEY))
+		return -1;
+
+	t1 = le32_to_cpu(k1->hash);
+	t2 = le32_to_cpu(k2->hash);
+
+	/* First value is a hash value itself */
+	if (t1 < t2)
+		return -1;
+	if (t1 > t2)
+		return 1;
+
+	/* Second value is security Id */
+	if (data) {
+		t1 = le32_to_cpu(k1->sec_id);
+		t2 = le32_to_cpu(k2->sec_id);
+		if (t1 < t2)
+			return -1;
+		if (t1 > t2)
+			return 1;
+	}
+
+	return 0;
+}
+
+/* $O of ObjId and "$R" for Reparse */
+static int cmp_uints(const void *key1, size_t l1, const void *key2, size_t l2,
+		     const void *data)
+{
+	const __le32 *k1 = key1;
+	const __le32 *k2 = key2;
+	size_t count;
+
+	if ((size_t)data == 1) {
+		/*
+		 * ni_delete_all -> ntfs_remove_reparse -> delete all with this reference
+		 * k1, k2 - pointers to REPARSE_KEY
+		 */
+
+		k1 += 1; // skip REPARSE_KEY.ReparseTag
+		k2 += 1; // skip REPARSE_KEY.ReparseTag
+		if (l2 <= sizeof(int))
+			return -1;
+		l2 -= sizeof(int);
+		if (l1 <= sizeof(int))
+			return 1;
+		l1 -= sizeof(int);
+	}
+
+	if (l2 < sizeof(int))
+		return -1;
+
+	for (count = min(l1, l2) >> 2; count > 0; --count, ++k1, ++k2) {
+		u32 t1 = le32_to_cpu(*k1);
+		u32 t2 = le32_to_cpu(*k2);
+
+		if (t1 > t2)
+			return 1;
+		if (t1 < t2)
+			return -1;
+	}
+
+	if (l1 > l2)
+		return 1;
+	if (l1 < l2)
+		return -1;
+
+	return 0;
+}
+
+static inline NTFS_CMP_FUNC get_cmp_func(const struct INDEX_ROOT *root)
+{
+	switch (root->type) {
+	case ATTR_NAME:
+		if (root->rule == NTFS_COLLATION_TYPE_FILENAME)
+			return &cmp_fnames;
+		break;
+	case ATTR_ZERO:
+		switch (root->rule) {
+		case NTFS_COLLATION_TYPE_UINT:
+			return &cmp_uint;
+		case NTFS_COLLATION_TYPE_SECURITY_HASH:
+			return &cmp_sdh;
+		case NTFS_COLLATION_TYPE_UINTS:
+			return &cmp_uints;
+		default:
+			break;
+		}
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+struct bmp_buf {
+	struct ATTRIB *b;
+	struct mft_inode *mi;
+	struct buffer_head *bh;
+	ulong *buf;
+	size_t bit;
+	u32 nbits;
+	u64 new_valid;
+};
+
+static int bmp_buf_get(struct ntfs_index *indx, struct ntfs_inode *ni,
+		       size_t bit, struct bmp_buf *bbuf)
+{
+	struct ATTRIB *b;
+	size_t data_size, valid_size, vbo, off = bit >> 3;
+	struct ntfs_sb_info *sbi = ni->mi.sbi;
+	CLST vcn = off >> sbi->cluster_bits;
+	struct ATTR_LIST_ENTRY *le = NULL;
+	struct buffer_head *bh;
+	struct super_block *sb;
+	u32 blocksize;
+	const struct INDEX_NAMES *in = &s_index_names[indx->type];
+
+	bbuf->bh = NULL;
+
+	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
+			 &vcn, &bbuf->mi);
+	bbuf->b = b;
+	if (!b)
+		return -EINVAL;
+
+	if (!b->non_res) {
+		data_size = le32_to_cpu(b->res.data_size);
+
+		if (off >= data_size)
+			return -EINVAL;
+
+		bbuf->buf = (ulong *)resident_data(b);
+		bbuf->bit = 0;
+		bbuf->nbits = data_size * 8;
+
+		return 0;
+	}
+
+	data_size = le64_to_cpu(b->nres.data_size);
+	if (WARN_ON(off >= data_size)) {
+		/* looks like filesystem error */
+		return -EINVAL;
+	}
+
+	valid_size = le64_to_cpu(b->nres.valid_size);
+
+	bh = ntfs_bread_run(sbi, &indx->bitmap_run, off);
+	if (!bh)
+		return -EIO;
+
+	if (IS_ERR(bh))
+		return PTR_ERR(bh);
+
+	bbuf->bh = bh;
+
+	if (buffer_locked(bh))
+		__wait_on_buffer(bh);
+
+	lock_buffer(bh);
+
+	sb = sbi->sb;
+	blocksize = sb->s_blocksize;
+
+	vbo = off & ~(size_t)sbi->block_mask;
+
+	bbuf->new_valid = vbo + blocksize;
+	if (bbuf->new_valid <= valid_size)
+		bbuf->new_valid = 0;
+	else if (bbuf->new_valid > data_size)
+		bbuf->new_valid = data_size;
+
+	if (vbo >= valid_size) {
+		memset(bh->b_data, 0, blocksize);
+	} else if (vbo + blocksize > valid_size) {
+		u32 voff = valid_size & sbi->block_mask;
+
+		memset(bh->b_data + voff, 0, blocksize - voff);
+	}
+
+	bbuf->buf = (ulong *)bh->b_data;
+	bbuf->bit = 8 * (off & ~(size_t)sbi->block_mask);
+	bbuf->nbits = 8 * blocksize;
+
+	return 0;
+}
+
+static void bmp_buf_put(struct bmp_buf *bbuf, bool dirty)
+{
+	struct buffer_head *bh = bbuf->bh;
+	struct ATTRIB *b = bbuf->b;
+
+	if (!bh) {
+		if (b && !b->non_res && dirty)
+			bbuf->mi->dirty = true;
+		return;
+	}
+
+	if (!dirty)
+		goto out;
+
+	if (bbuf->new_valid) {
+		b->nres.valid_size = cpu_to_le64(bbuf->new_valid);
+		bbuf->mi->dirty = true;
+	}
+
+	set_buffer_uptodate(bh);
+	mark_buffer_dirty(bh);
+
+out:
+	unlock_buffer(bh);
+	put_bh(bh);
+}
+
+/*
+ * indx_mark_used
+ *
+ * marks the bit 'bit' as used
+ */
+static int indx_mark_used(struct ntfs_index *indx, struct ntfs_inode *ni,
+			  size_t bit)
+{
+	int err;
+	struct bmp_buf bbuf;
+
+	err = bmp_buf_get(indx, ni, bit, &bbuf);
+	if (err)
+		return err;
+
+	__set_bit(bit - bbuf.bit, bbuf.buf);
+
+	bmp_buf_put(&bbuf, true);
+
+	return 0;
+}
+
+/*
+ * indx_mark_free
+ *
+ * the bit 'bit' as free
+ */
+static int indx_mark_free(struct ntfs_index *indx, struct ntfs_inode *ni,
+			  size_t bit)
+{
+	int err;
+	struct bmp_buf bbuf;
+
+	err = bmp_buf_get(indx, ni, bit, &bbuf);
+	if (err)
+		return err;
+
+	__clear_bit(bit - bbuf.bit, bbuf.buf);
+
+	bmp_buf_put(&bbuf, true);
+
+	return 0;
+}
+
+/*
+ * if ntfs_readdir calls this function (indx_used_bit -> scan_nres_bitmap),
+ * inode is shared locked and no ni_lock
+ * use rw_semaphore for read/write access to bitmap_run
+ */
+static int scan_nres_bitmap(struct ntfs_inode *ni, struct ATTRIB *bitmap,
+			    struct ntfs_index *indx, size_t from,
+			    bool (*fn)(const ulong *buf, u32 bit, u32 bits,
+				       size_t *ret),
+			    size_t *ret)
+{
+	struct ntfs_sb_info *sbi = ni->mi.sbi;
+	struct super_block *sb = sbi->sb;
+	struct runs_tree *run = &indx->bitmap_run;
+	struct rw_semaphore *lock = &indx->run_lock;
+	u32 nbits = sb->s_blocksize * 8;
+	u32 blocksize = sb->s_blocksize;
+	u64 valid_size = le64_to_cpu(bitmap->nres.valid_size);
+	u64 data_size = le64_to_cpu(bitmap->nres.data_size);
+	sector_t eblock = bytes_to_block(sb, data_size);
+	size_t vbo = from >> 3;
+	sector_t blk = (vbo & sbi->cluster_mask) >> sb->s_blocksize_bits;
+	sector_t vblock = vbo >> sb->s_blocksize_bits;
+	sector_t blen, block;
+	CLST lcn, clen, vcn, vcn_next;
+	size_t idx;
+	struct buffer_head *bh;
+	bool ok;
+
+	*ret = MINUS_ONE_T;
+
+	if (vblock >= eblock)
+		return 0;
+
+	from &= nbits - 1;
+	vcn = vbo >> sbi->cluster_bits;
+
+	down_read(lock);
+	ok = run_lookup_entry(run, vcn, &lcn, &clen, &idx);
+	up_read(lock);
+
+next_run:
+	if (!ok) {
+		int err;
+		const struct INDEX_NAMES *name = &s_index_names[indx->type];
+
+		down_write(lock);
+		err = attr_load_runs_vcn(ni, ATTR_BITMAP, name->name,
+					 name->name_len, run, vcn);
+		up_write(lock);
+		if (err)
+			return err;
+		down_read(lock);
+		ok = run_lookup_entry(run, vcn, &lcn, &clen, &idx);
+		up_read(lock);
+		if (!ok)
+			return -EINVAL;
+	}
+
+	blen = (sector_t)clen * sbi->blocks_per_cluster;
+	block = (sector_t)lcn * sbi->blocks_per_cluster;
+
+	for (; blk < blen; blk++, from = 0) {
+		bh = ntfs_bread(sb, block + blk);
+		if (!bh)
+			return -EIO;
+
+		vbo = (u64)vblock << sb->s_blocksize_bits;
+		if (vbo >= valid_size) {
+			memset(bh->b_data, 0, blocksize);
+		} else if (vbo + blocksize > valid_size) {
+			u32 voff = valid_size & sbi->block_mask;
+
+			memset(bh->b_data + voff, 0, blocksize - voff);
+		}
+
+		if (vbo + blocksize > data_size)
+			nbits = 8 * (data_size - vbo);
+
+		ok = nbits > from ? (*fn)((ulong *)bh->b_data, from, nbits, ret)
+				  : false;
+		put_bh(bh);
+
+		if (ok) {
+			*ret += 8 * vbo;
+			return 0;
+		}
+
+		if (++vblock >= eblock) {
+			*ret = MINUS_ONE_T;
+			return 0;
+		}
+	}
+	blk = 0;
+	vcn_next = vcn + clen;
+	down_read(lock);
+	ok = run_get_entry(run, ++idx, &vcn, &lcn, &clen) && vcn == vcn_next;
+	if (!ok)
+		vcn = vcn_next;
+	up_read(lock);
+	goto next_run;
+}
+
+static bool scan_for_free(const ulong *buf, u32 bit, u32 bits, size_t *ret)
+{
+	size_t pos = find_next_zero_bit(buf, bits, bit);
+
+	if (pos >= bits)
+		return false;
+	*ret = pos;
+	return true;
+}
+
+/*
+ * indx_find_free
+ *
+ * looks for free bit
+ * returns -1 if no free bits
+ */
+static int indx_find_free(struct ntfs_index *indx, struct ntfs_inode *ni,
+			  size_t *bit, struct ATTRIB **bitmap)
+{
+	struct ATTRIB *b;
+	struct ATTR_LIST_ENTRY *le = NULL;
+	const struct INDEX_NAMES *in = &s_index_names[indx->type];
+	int err;
+
+	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
+			 NULL, NULL);
+
+	if (!b)
+		return -ENOENT;
+
+	*bitmap = b;
+	*bit = MINUS_ONE_T;
+
+	if (!b->non_res) {
+		u32 nbits = 8 * le32_to_cpu(b->res.data_size);
+		size_t pos = find_next_zero_bit(resident_data(b), nbits, 0);
+
+		if (pos < nbits)
+			*bit = pos;
+	} else {
+		err = scan_nres_bitmap(ni, b, indx, 0, &scan_for_free, bit);
+
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static bool scan_for_used(const ulong *buf, u32 bit, u32 bits, size_t *ret)
+{
+	size_t pos = find_next_bit(buf, bits, bit);
+
+	if (pos >= bits)
+		return false;
+	*ret = pos;
+	return true;
+}
+
+/*
+ * indx_used_bit
+ *
+ * looks for used bit
+ * returns MINUS_ONE_T if no used bits
+ */
+int indx_used_bit(struct ntfs_index *indx, struct ntfs_inode *ni, size_t *bit)
+{
+	struct ATTRIB *b;
+	struct ATTR_LIST_ENTRY *le = NULL;
+	size_t from = *bit;
+	const struct INDEX_NAMES *in = &s_index_names[indx->type];
+	int err;
+
+	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
+			 NULL, NULL);
+
+	if (!b)
+		return -ENOENT;
+
+	*bit = MINUS_ONE_T;
+
+	if (!b->non_res) {
+		u32 nbits = le32_to_cpu(b->res.data_size) * 8;
+		size_t pos = find_next_bit(resident_data(b), nbits, from);
+
+		if (pos < nbits)
+			*bit = pos;
+	} else {
+		err = scan_nres_bitmap(ni, b, indx, from, &scan_for_used, bit);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+/*
+ * hdr_find_split
+ *
+ * finds a point at which the index allocation buffer would like to
+ * be split.
+ * NOTE: This function should never return 'END' entry NULL returns on error
+ */
+static const struct NTFS_DE *hdr_find_split(const struct INDEX_HDR *hdr)
+{
+	size_t o;
+	const struct NTFS_DE *e = hdr_first_de(hdr);
+	u32 used_2 = le32_to_cpu(hdr->used) >> 1;
+	u16 esize = le16_to_cpu(e->size);
+
+	if (!e || de_is_last(e))
+		return NULL;
+
+	for (o = le32_to_cpu(hdr->de_off) + esize; o < used_2; o += esize) {
+		const struct NTFS_DE *p = e;
+
+		e = Add2Ptr(hdr, o);
+
+		/* We must not return END entry */
+		if (de_is_last(e))
+			return p;
+
+		esize = le16_to_cpu(e->size);
+	}
+
+	return e;
+}
+
+/*
+ * hdr_insert_head
+ *
+ * inserts some entries at the beginning of the buffer.
+ * It is used to insert entries into a newly-created buffer.
+ */
+static const struct NTFS_DE *hdr_insert_head(struct INDEX_HDR *hdr,
+					     const void *ins, u32 ins_bytes)
+{
+	u32 to_move;
+	struct NTFS_DE *e = hdr_first_de(hdr);
+	u32 used = le32_to_cpu(hdr->used);
+
+	if (!e)
+		return NULL;
+
+	/* Now we just make room for the inserted entries and jam it in. */
+	to_move = used - le32_to_cpu(hdr->de_off);
+	memmove(Add2Ptr(e, ins_bytes), e, to_move);
+	memcpy(e, ins, ins_bytes);
+	hdr->used = cpu_to_le32(used + ins_bytes);
+
+	return e;
+}
+
+void fnd_clear(struct ntfs_fnd *fnd)
+{
+	int i;
+
+	for (i = 0; i < fnd->level; i++) {
+		struct indx_node *n = fnd->nodes[i];
+
+		if (!n)
+			continue;
+
+		put_indx_node(n);
+		fnd->nodes[i] = NULL;
+	}
+	fnd->level = 0;
+	fnd->root_de = NULL;
+}
+
+static int fnd_push(struct ntfs_fnd *fnd, struct indx_node *n,
+		    struct NTFS_DE *e)
+{
+	int i;
+
+	i = fnd->level;
+	if (i < 0 || i >= ARRAY_SIZE(fnd->nodes))
+		return -EINVAL;
+	fnd->nodes[i] = n;
+	fnd->de[i] = e;
+	fnd->level += 1;
+	return 0;
+}
+
+static struct indx_node *fnd_pop(struct ntfs_fnd *fnd)
+{
+	struct indx_node *n;
+	int i = fnd->level;
+
+	i -= 1;
+	n = fnd->nodes[i];
+	fnd->nodes[i] = NULL;
+	fnd->level = i;
+
+	return n;
+}
+
+static bool fnd_is_empty(struct ntfs_fnd *fnd)
+{
+	if (!fnd->level)
+		return !fnd->root_de;
+
+	return !fnd->de[fnd->level - 1];
+}
+
+/*
+ * hdr_find_e
+ *
+ * locates an entry the index buffer.
+ * If no matching entry is found, it returns the first entry which is greater
+ * than the desired entry If the search key is greater than all the entries the
+ * buffer, it returns the 'end' entry. This function does a binary search of the
+ * current index buffer, for the first entry that is <= to the search value
+ * Returns NULL if error
+ */
+static struct NTFS_DE *hdr_find_e(const struct ntfs_index *indx,
+				  const struct INDEX_HDR *hdr, const void *key,
+				  size_t key_len, const void *ctx, int *diff)
+{
+	struct NTFS_DE *e;
+	NTFS_CMP_FUNC cmp = indx->cmp;
+	u32 e_size, e_key_len;
+	u32 end = le32_to_cpu(hdr->used);
+	u32 off = le32_to_cpu(hdr->de_off);
+
+#ifdef NTFS3_INDEX_BINARY_SEARCH
+	int max_idx = 0, fnd, min_idx;
+	int nslots = 64;
+	u16 *offs;
+
+	if (end > 0x10000)
+		goto next;
+
+	offs = ntfs_malloc(sizeof(u16) * nslots);
+	if (!offs)
+		goto next;
+
+	/* use binary search algorithm */
+next1:
+	if (off + sizeof(struct NTFS_DE) > end) {
+		e = NULL;
+		goto out1;
+	}
+	e = Add2Ptr(hdr, off);
+	e_size = le16_to_cpu(e->size);
+
+	if (e_size < sizeof(struct NTFS_DE) || off + e_size > end) {
+		e = NULL;
+		goto out1;
+	}
+
+	if (max_idx >= nslots) {
+		u16 *ptr;
+		int new_slots = QuadAlign(2 * nslots);
+
+		ptr = ntfs_malloc(sizeof(u16) * new_slots);
+		if (ptr)
+			memcpy(ptr, offs, sizeof(u16) * max_idx);
+		ntfs_free(offs);
+		offs = ptr;
+		nslots = new_slots;
+		if (!ptr)
+			goto next;
+	}
+
+	/* Store entry table */
+	offs[max_idx] = off;
+
+	if (!de_is_last(e)) {
+		off += e_size;
+		max_idx += 1;
+		goto next1;
+	}
+
+	/*
+	 * Table of pointers is created
+	 * Use binary search to find entry that is <= to the search value
+	 */
+	fnd = -1;
+	min_idx = 0;
+
+	while (min_idx <= max_idx) {
+		int mid_idx = min_idx + ((max_idx - min_idx) >> 1);
+		int diff2;
+
+		e = Add2Ptr(hdr, offs[mid_idx]);
+
+		e_key_len = le16_to_cpu(e->key_size);
+
+		diff2 = (*cmp)(key, key_len, e + 1, e_key_len, ctx);
+
+		if (!diff2) {
+			*diff = 0;
+			goto out1;
+		}
+
+		if (diff2 < 0) {
+			max_idx = mid_idx - 1;
+			fnd = mid_idx;
+			if (!fnd)
+				break;
+		} else {
+			min_idx = mid_idx + 1;
+		}
+	}
+
+	if (fnd == -1) {
+		e = NULL;
+		goto out1;
+	}
+
+	*diff = -1;
+	e = Add2Ptr(hdr, offs[fnd]);
+
+out1:
+	ntfs_free(offs);
+
+	return e;
+#endif
+
+next:
+	/*
+	 * Entries index are sorted
+	 * Enumerate all entries until we find entry that is <= to the search value
+	 */
+	if (off + sizeof(struct NTFS_DE) > end)
+		return NULL;
+
+	e = Add2Ptr(hdr, off);
+	e_size = le16_to_cpu(e->size);
+
+	if (e_size < sizeof(struct NTFS_DE) || off + e_size > end)
+		return NULL;
+
+	off += e_size;
+
+	e_key_len = le16_to_cpu(e->key_size);
+
+	*diff = (*cmp)(key, key_len, e + 1, e_key_len, ctx);
+	if (!*diff)
+		return e;
+
+	if (*diff <= 0)
+		return e;
+
+	if (de_is_last(e)) {
+		*diff = 1;
+		return e;
+	}
+	goto next;
+}
+
+/*
+ * hdr_insert_de
+ *
+ * inserts an index entry into the buffer.
+ * 'before' should be a pointer previously returned from hdr_find_e
+ */
+static struct NTFS_DE *hdr_insert_de(const struct ntfs_index *indx,
+				     struct INDEX_HDR *hdr,
+				     const struct NTFS_DE *de,
+				     struct NTFS_DE *before, const void *ctx)
+{
+	int diff;
+	size_t off = PtrOffset(hdr, before);
+	u32 used = le32_to_cpu(hdr->used);
+	u32 total = le32_to_cpu(hdr->total);
+	u16 de_size = le16_to_cpu(de->size);
+
+	/* First, check to see if there's enough room */
+	if (used + de_size > total)
+		return NULL;
+
+	/* We know there's enough space, so we know we'll succeed. */
+	if (before) {
+		/* Check that before is inside Index */
+		if (off >= used || off < le32_to_cpu(hdr->de_off) ||
+		    off + le16_to_cpu(before->size) > total) {
+			return NULL;
+		}
+		goto ok;
+	}
+	/* No insert point is applied. Get it manually */
+	before = hdr_find_e(indx, hdr, de + 1, le16_to_cpu(de->key_size), ctx,
+			    &diff);
+	if (!before)
+		return NULL;
+	off = PtrOffset(hdr, before);
+
+ok:
+	/* Now we just make room for the entry and jam it in. */
+	memmove(Add2Ptr(before, de_size), before, used - off);
+
+	hdr->used = cpu_to_le32(used + de_size);
+	memcpy(before, de, de_size);
+
+	return before;
+}
+
+/*
+ * hdr_delete_de
+ *
+ * removes an entry from the index buffer
+ */
+static inline struct NTFS_DE *hdr_delete_de(struct INDEX_HDR *hdr,
+					    struct NTFS_DE *re)
+{
+	u32 used = le32_to_cpu(hdr->used);
+	u16 esize = le16_to_cpu(re->size);
+	u32 off = PtrOffset(hdr, re);
+	int bytes = used - (off + esize);
+
+	if (off >= used || esize < sizeof(struct NTFS_DE) ||
+	    bytes < sizeof(struct NTFS_DE))
+		return NULL;
+
+	hdr->used = cpu_to_le32(used - esize);
+	memmove(re, Add2Ptr(re, esize), bytes);
+
+	return re;
+}
+
+void indx_clear(struct ntfs_index *indx)
+{
+	run_close(&indx->alloc_run);
+	run_close(&indx->bitmap_run);
+}
+
+int indx_init(struct ntfs_index *indx, struct ntfs_sb_info *sbi,
+	      const struct ATTRIB *attr, enum index_mutex_classed type)
+{
+	u32 t32;
+	const struct INDEX_ROOT *root = resident_data(attr);
+
+	/* Check root fields */
+	if (!root->index_block_clst)
+		return -EINVAL;
+
+	indx->type = type;
+	indx->idx2vbn_bits = __ffs(root->index_block_clst);
+
+	t32 = le32_to_cpu(root->index_block_size);
+	indx->index_bits = blksize_bits(t32);
+
+	/* Check index record size */
+	if (t32 < sbi->cluster_size) {
+		/* index record is smaller than a cluster, use 512 blocks */
+		if (t32 != root->index_block_clst * SECTOR_SIZE)
+			return -EINVAL;
+
+		/* Check alignment to a cluster */
+		if ((sbi->cluster_size >> SECTOR_SHIFT) &
+		    (root->index_block_clst - 1)) {
+			return -EINVAL;
+		}
+
+		indx->vbn2vbo_bits = SECTOR_SHIFT;
+	} else {
+		/* index record must be a multiple of cluster size */
+		if (t32 != root->index_block_clst << sbi->cluster_bits)
+			return -EINVAL;
+
+		indx->vbn2vbo_bits = sbi->cluster_bits;
+	}
+
+	init_rwsem(&indx->run_lock);
+
+	indx->cmp = get_cmp_func(root);
+	return indx->cmp ? 0 : -EINVAL;
+}
+
+static struct indx_node *indx_new(struct ntfs_index *indx,
+				  struct ntfs_inode *ni, CLST vbn,
+				  const __le64 *sub_vbn)
+{
+	int err;
+	struct NTFS_DE *e;
+	struct indx_node *r;
+	struct INDEX_HDR *hdr;
+	struct INDEX_BUFFER *index;
+	u64 vbo = (u64)vbn << indx->vbn2vbo_bits;
+	u32 bytes = 1u << indx->index_bits;
+	u16 fn;
+	u32 eo;
+
+	r = ntfs_zalloc(sizeof(struct indx_node));
+	if (!r)
+		return ERR_PTR(-ENOMEM);
+
+	index = ntfs_zalloc(bytes);
+	if (!index) {
+		ntfs_free(r);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	err = ntfs_get_bh(ni->mi.sbi, &indx->alloc_run, vbo, bytes, &r->nb);
+
+	if (err) {
+		ntfs_free(index);
+		ntfs_free(r);
+		return ERR_PTR(err);
+	}
+
+	/* Create header */
+	index->rhdr.sign = NTFS_INDX_SIGNATURE;
+	index->rhdr.fix_off = cpu_to_le16(sizeof(struct INDEX_BUFFER)); // 0x28
+	fn = (bytes >> SECTOR_SHIFT) + 1; // 9
+	index->rhdr.fix_num = cpu_to_le16(fn);
+	index->vbn = cpu_to_le64(vbn);
+	hdr = &index->ihdr;
+	eo = QuadAlign(sizeof(struct INDEX_BUFFER) + fn * sizeof(short));
+	hdr->de_off = cpu_to_le32(eo);
+
+	e = Add2Ptr(hdr, eo);
+
+	if (sub_vbn) {
+		e->flags = NTFS_IE_LAST | NTFS_IE_HAS_SUBNODES;
+		e->size = cpu_to_le16(sizeof(struct NTFS_DE) + sizeof(u64));
+		hdr->used =
+			cpu_to_le32(eo + sizeof(struct NTFS_DE) + sizeof(u64));
+		de_set_vbn_le(e, *sub_vbn);
+		hdr->flags = 1;
+	} else {
+		e->size = cpu_to_le16(sizeof(struct NTFS_DE));
+		hdr->used = cpu_to_le32(eo + sizeof(struct NTFS_DE));
+		e->flags = NTFS_IE_LAST;
+	}
+
+	hdr->total = cpu_to_le32(bytes - offsetof(struct INDEX_BUFFER, ihdr));
+
+	r->index = index;
+	return r;
+}
+
+struct INDEX_ROOT *indx_get_root(struct ntfs_index *indx, struct ntfs_inode *ni,
+				 struct ATTRIB **attr, struct mft_inode **mi)
+{
+	struct ATTR_LIST_ENTRY *le = NULL;
+	struct ATTRIB *a;
+	const struct INDEX_NAMES *in = &s_index_names[indx->type];
+
+	a = ni_find_attr(ni, NULL, &le, ATTR_ROOT, in->name, in->name_len, NULL,
+			 mi);
+	if (!a)
+		return NULL;
+
+	if (attr)
+		*attr = a;
+
+	return resident_data_ex(a, sizeof(struct INDEX_ROOT));
+}
+
+static int indx_write(struct ntfs_index *indx, struct ntfs_inode *ni,
+		      struct indx_node *node, int sync)
+{
+	struct INDEX_BUFFER *ib = node->index;
+
+	return ntfs_write_bh(ni->mi.sbi, &ib->rhdr, &node->nb, sync);
+}
+
+/*
+ * if ntfs_readdir calls this function
+ * inode is shared locked and no ni_lock
+ * use rw_semaphore for read/write access to alloc_run
+ */
+int indx_read(struct ntfs_index *indx, struct ntfs_inode *ni, CLST vbn,
+	      struct indx_node **node)
+{
+	int err;
+	struct INDEX_BUFFER *ib;
+	struct runs_tree *run = &indx->alloc_run;
+	struct rw_semaphore *lock = &indx->run_lock;
+	u64 vbo = (u64)vbn << indx->vbn2vbo_bits;
+	u32 bytes = 1u << indx->index_bits;
+	struct indx_node *in = *node;
+	const struct INDEX_NAMES *name;
+
+	if (!in) {
+		in = ntfs_zalloc(sizeof(struct indx_node));
+		if (!in)
+			return -ENOMEM;
+	} else {
+		nb_put(&in->nb);
+	}
+
+	ib = in->index;
+	if (!ib) {
+		ib = ntfs_malloc(bytes);
+		if (!ib) {
+			err = -ENOMEM;
+			goto out;
+		}
+	}
+
+	down_read(lock);
+	err = ntfs_read_bh(ni->mi.sbi, run, vbo, &ib->rhdr, bytes, &in->nb);
+	up_read(lock);
+	if (!err)
+		goto ok;
+
+	if (err == -E_NTFS_FIXUP)
+		goto ok;
+
+	if (err != -ENOENT)
+		goto out;
+
+	name = &s_index_names[indx->type];
+	down_write(lock);
+	err = attr_load_runs_range(ni, ATTR_ALLOC, name->name, name->name_len,
+				   run, vbo, vbo + bytes);
+	up_write(lock);
+	if (err)
+		goto out;
+
+	down_read(lock);
+	err = ntfs_read_bh(ni->mi.sbi, run, vbo, &ib->rhdr, bytes, &in->nb);
+	up_read(lock);
+	if (err == -E_NTFS_FIXUP)
+		goto ok;
+
+	if (err)
+		goto out;
+
+ok:
+	if (err == -E_NTFS_FIXUP) {
+		ntfs_write_bh(ni->mi.sbi, &ib->rhdr, &in->nb, 0);
+		err = 0;
+	}
+
+	in->index = ib;
+	*node = in;
+
+out:
+	if (ib != in->index)
+		ntfs_free(ib);
+
+	if (*node != in) {
+		nb_put(&in->nb);
+		ntfs_free(in);
+	}
+
+	return err;
+}
+
+/*
+ * indx_find
+ *
+ * scans NTFS directory for given entry
+ */
+int indx_find(struct ntfs_index *indx, struct ntfs_inode *ni,
+	      const struct INDEX_ROOT *root, const void *key, size_t key_len,
+	      const void *ctx, int *diff, struct NTFS_DE **entry,
+	      struct ntfs_fnd *fnd)
+{
+	int err;
+	struct NTFS_DE *e;
+	const struct INDEX_HDR *hdr;
+	struct indx_node *node;
+
+	if (!root)
+		root = indx_get_root(&ni->dir, ni, NULL, NULL);
+
+	if (!root) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	hdr = &root->ihdr;
+
+	/* Check cache */
+	e = fnd->level ? fnd->de[fnd->level - 1] : fnd->root_de;
+	if (e && !de_is_last(e) &&
+	    !(*indx->cmp)(key, key_len, e + 1, le16_to_cpu(e->key_size), ctx)) {
+		*entry = e;
+		*diff = 0;
+		return 0;
+	}
+
+	/* Soft finder reset */
+	fnd_clear(fnd);
+
+	/* Lookup entry that is <= to the search value */
+	e = hdr_find_e(indx, hdr, key, key_len, ctx, diff);
+	if (!e)
+		return -EINVAL;
+
+	if (fnd)
+		fnd->root_de = e;
+
+	err = 0;
+
+	for (;;) {
+		node = NULL;
+		if (*diff >= 0 || !de_has_vcn_ex(e)) {
+			*entry = e;
+			goto out;
+		}
+
+		/* Read next level. */
+		err = indx_read(indx, ni, de_get_vbn(e), &node);
+		if (err)
+			goto out;
+
+		/* Lookup entry that is <= to the search value */
+		e = hdr_find_e(indx, &node->index->ihdr, key, key_len, ctx,
+			       diff);
+		if (!e) {
+			err = -EINVAL;
+			put_indx_node(node);
+			goto out;
+		}
+
+		fnd_push(fnd, node, e);
+	}
+
+out:
+	return err;
+}
+
+int indx_find_sort(struct ntfs_index *indx, struct ntfs_inode *ni,
+		   const struct INDEX_ROOT *root, struct NTFS_DE **entry,
+		   struct ntfs_fnd *fnd)
+{
+	int err;
+	struct indx_node *n = NULL;
+	struct NTFS_DE *e;
+	size_t iter = 0;
+	int level = fnd->level;
+
+	if (!*entry) {
+		/* Start find */
+		e = hdr_first_de(&root->ihdr);
+		if (!e)
+			return 0;
+		fnd_clear(fnd);
+		fnd->root_de = e;
+	} else if (!level) {
+		if (de_is_last(fnd->root_de)) {
+			*entry = NULL;
+			return 0;
+		}
+
+		e = hdr_next_de(&root->ihdr, fnd->root_de);
+		if (!e)
+			return -EINVAL;
+		fnd->root_de = e;
+	} else {
+		n = fnd->nodes[level - 1];
+		e = fnd->de[level - 1];
+
+		if (de_is_last(e))
+			goto pop_level;
+
+		e = hdr_next_de(&n->index->ihdr, e);
+		if (!e)
+			return -EINVAL;
+
+		fnd->de[level - 1] = e;
+	}
+
+	/* Just to avoid tree cycle */
+next_iter:
+	if (iter++ >= 1000)
+		return -EINVAL;
+
+	while (de_has_vcn_ex(e)) {
+		if (le16_to_cpu(e->size) <
+		    sizeof(struct NTFS_DE) + sizeof(u64)) {
+			if (n) {
+				fnd_pop(fnd);
+				ntfs_free(n);
+			}
+			return -EINVAL;
+		}
+
+		/* Read next level */
+		err = indx_read(indx, ni, de_get_vbn(e), &n);
+		if (err)
+			return err;
+
+		/* Try next level */
+		e = hdr_first_de(&n->index->ihdr);
+		if (!e) {
+			ntfs_free(n);
+			return -EINVAL;
+		}
+
+		fnd_push(fnd, n, e);
+	}
+
+	if (le16_to_cpu(e->size) > sizeof(struct NTFS_DE)) {
+		*entry = e;
+		return 0;
+	}
+
+pop_level:
+	for (;;) {
+		if (!de_is_last(e))
+			goto next_iter;
+
+		/* Pop one level */
+		if (n) {
+			fnd_pop(fnd);
+			ntfs_free(n);
+		}
+
+		level = fnd->level;
+
+		if (level) {
+			n = fnd->nodes[level - 1];
+			e = fnd->de[level - 1];
+		} else if (fnd->root_de) {
+			n = NULL;
+			e = fnd->root_de;
+			fnd->root_de = NULL;
+		} else {
+			*entry = NULL;
+			return 0;
+		}
+
+		if (le16_to_cpu(e->size) > sizeof(struct NTFS_DE)) {
+			*entry = e;
+			if (!fnd->root_de)
+				fnd->root_de = e;
+			return 0;
+		}
+	}
+}
+
+int indx_find_raw(struct ntfs_index *indx, struct ntfs_inode *ni,
+		  const struct INDEX_ROOT *root, struct NTFS_DE **entry,
+		  size_t *off, struct ntfs_fnd *fnd)
+{
+	int err;
+	struct indx_node *n = NULL;
+	struct NTFS_DE *e = NULL;
+	struct NTFS_DE *e2;
+	size_t bit;
+	CLST next_used_vbn;
+	CLST next_vbn;
+	u32 record_size = ni->mi.sbi->record_size;
+
+	/* Use non sorted algorithm */
+	if (!*entry) {
+		/* This is the first call */
+		e = hdr_first_de(&root->ihdr);
+		if (!e)
+			return 0;
+		fnd_clear(fnd);
+		fnd->root_de = e;
+
+		/* The first call with setup of initial element */
+		if (*off >= record_size) {
+			next_vbn = (((*off - record_size) >> indx->index_bits))
+				   << indx->idx2vbn_bits;
+			/* jump inside cycle 'for'*/
+			goto next;
+		}
+
+		/* Start enumeration from root */
+		*off = 0;
+	} else if (!fnd->root_de)
+		return -EINVAL;
+
+	for (;;) {
+		/* Check if current entry can be used */
+		if (e && le16_to_cpu(e->size) > sizeof(struct NTFS_DE))
+			goto ok;
+
+		if (!fnd->level) {
+			/* Continue to enumerate root */
+			if (!de_is_last(fnd->root_de)) {
+				e = hdr_next_de(&root->ihdr, fnd->root_de);
+				if (!e)
+					return -EINVAL;
+				fnd->root_de = e;
+				continue;
+			}
+
+			/* Start to enumerate indexes from 0 */
+			next_vbn = 0;
+		} else {
+			/* Continue to enumerate indexes */
+			e2 = fnd->de[fnd->level - 1];
+
+			n = fnd->nodes[fnd->level - 1];
+
+			if (!de_is_last(e2)) {
+				e = hdr_next_de(&n->index->ihdr, e2);
+				if (!e)
+					return -EINVAL;
+				fnd->de[fnd->level - 1] = e;
+				continue;
+			}
+
+			/* Continue with next index */
+			next_vbn = le64_to_cpu(n->index->vbn) +
+				   root->index_block_clst;
+		}
+
+next:
+		/* Release current index */
+		if (n) {
+			fnd_pop(fnd);
+			put_indx_node(n);
+			n = NULL;
+		}
+
+		/* Skip all free indexes */
+		bit = next_vbn >> indx->idx2vbn_bits;
+		err = indx_used_bit(indx, ni, &bit);
+		if (err == -ENOENT || bit == MINUS_ONE_T) {
+			/* No used indexes */
+			*entry = NULL;
+			return 0;
+		}
+
+		next_used_vbn = bit << indx->idx2vbn_bits;
+
+		/* Read buffer into memory */
+		err = indx_read(indx, ni, next_used_vbn, &n);
+		if (err)
+			return err;
+
+		e = hdr_first_de(&n->index->ihdr);
+		fnd_push(fnd, n, e);
+		if (!e)
+			return -EINVAL;
+	}
+
+ok:
+	/* return offset to restore enumerator if necessary */
+	if (!n) {
+		/* 'e' points in root */
+		*off = PtrOffset(&root->ihdr, e);
+	} else {
+		/* 'e' points in index */
+		*off = (le64_to_cpu(n->index->vbn) << indx->vbn2vbo_bits) +
+		       record_size + PtrOffset(&n->index->ihdr, e);
+	}
+
+	*entry = e;
+	return 0;
+}
+
+/*
+ * indx_create_allocate
+ *
+ * create "Allocation + Bitmap" attributes
+ */
+static int indx_create_allocate(struct ntfs_index *indx, struct ntfs_inode *ni,
+				CLST *vbn)
+{
+	int err = -ENOMEM;
+	struct ntfs_sb_info *sbi = ni->mi.sbi;
+	struct ATTRIB *bitmap;
+	struct ATTRIB *alloc;
+	u32 data_size = 1u << indx->index_bits;
+	u32 alloc_size = ntfs_up_cluster(sbi, data_size);
+	CLST len = alloc_size >> sbi->cluster_bits;
+	const struct INDEX_NAMES *in = &s_index_names[indx->type];
+	CLST alen;
+	struct runs_tree run;
+
+	run_init(&run);
+
+	err = attr_allocate_clusters(sbi, &run, 0, 0, len, NULL, 0, &alen, 0,
+				     NULL);
+	if (err)
+		goto out;
+
+	err = ni_insert_nonresident(ni, ATTR_ALLOC, in->name, in->name_len,
+				    &run, 0, len, 0, &alloc, NULL);
+	if (err)
+		goto out1;
+
+	alloc->nres.valid_size = alloc->nres.data_size = cpu_to_le64(data_size);
+
+	err = ni_insert_resident(ni, bitmap_size(1), ATTR_BITMAP, in->name,
+				 in->name_len, &bitmap, NULL);
+	if (err)
+		goto out2;
+
+	if (in->name == I30_NAME) {
+		ni->vfs_inode.i_size = data_size;
+		inode_set_bytes(&ni->vfs_inode, alloc_size);
+	}
+
+	memcpy(&indx->alloc_run, &run, sizeof(run));
+
+	*vbn = 0;
+
+	return 0;
+
+out2:
+	mi_remove_attr(&ni->mi, alloc);
+
+out1:
+	run_deallocate(sbi, &run, false);
+
+out:
+	return err;
+}
+
+/*
+ * indx_add_allocate
+ *
+ * add clusters to index
+ */
+static int indx_add_allocate(struct ntfs_index *indx, struct ntfs_inode *ni,
+			     CLST *vbn)
+{
+	int err;
+	size_t bit;
+	u64 data_size;
+	u64 bmp_size, bmp_size_v;
+	struct ATTRIB *bmp, *alloc;
+	struct mft_inode *mi;
+	const struct INDEX_NAMES *in = &s_index_names[indx->type];
+
+	err = indx_find_free(indx, ni, &bit, &bmp);
+	if (err)
+		goto out1;
+
+	if (bit != MINUS_ONE_T) {
+		bmp = NULL;
+	} else {
+		if (bmp->non_res) {
+			bmp_size = le64_to_cpu(bmp->nres.data_size);
+			bmp_size_v = le64_to_cpu(bmp->nres.valid_size);
+		} else {
+			bmp_size = bmp_size_v = le32_to_cpu(bmp->res.data_size);
+		}
+
+		bit = bmp_size << 3;
+	}
+
+	data_size = (u64)(bit + 1) << indx->index_bits;
+
+	if (bmp) {
+		/* Increase bitmap */
+		err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
+				    &indx->bitmap_run, bitmap_size(bit + 1),
+				    NULL, true, NULL);
+		if (err)
+			goto out1;
+	}
+
+	alloc = ni_find_attr(ni, NULL, NULL, ATTR_ALLOC, in->name, in->name_len,
+			     NULL, &mi);
+	if (!alloc) {
+		if (bmp)
+			goto out2;
+		goto out1;
+	}
+
+	/* Increase allocation */
+	err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
+			    &indx->alloc_run, data_size, &data_size, true,
+			    NULL);
+	if (err) {
+		if (bmp)
+			goto out2;
+		goto out1;
+	}
+
+	*vbn = bit << indx->idx2vbn_bits;
+
+	return 0;
+
+out2:
+	/* Ops (no space?) */
+	attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
+		      &indx->bitmap_run, bmp_size, &bmp_size_v, false, NULL);
+
+out1:
+	return err;
+}
+
+/*
+ * indx_insert_into_root
+ *
+ * attempts to insert an entry into the index root
+ * If necessary, it will twiddle the index b-tree.
+ */
+static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
+				 const struct NTFS_DE *new_de,
+				 struct NTFS_DE *root_de, const void *ctx,
+				 struct ntfs_fnd *fnd)
+{
+	int err = 0;
+	struct NTFS_DE *e, *e0, *re;
+	struct mft_inode *mi;
+	struct ATTRIB *attr;
+	struct MFT_REC *rec;
+	struct INDEX_HDR *hdr;
+	struct indx_node *n;
+	CLST new_vbn;
+	__le64 *sub_vbn, t_vbn;
+	u16 new_de_size;
+	u32 hdr_used, hdr_total, asize, used, to_move;
+	u32 root_size, new_root_size;
+	struct ntfs_sb_info *sbi;
+	int ds_root;
+	struct INDEX_ROOT *root, *a_root = NULL;
+
+	/* Get the record this root placed in */
+	root = indx_get_root(indx, ni, &attr, &mi);
+	if (!root)
+		goto out;
+
+	/*
+	 * Try easy case:
+	 * hdr_insert_de will succeed if there's room the root for the new entry.
+	 */
+	hdr = &root->ihdr;
+	sbi = ni->mi.sbi;
+	rec = mi->mrec;
+	used = le32_to_cpu(rec->used);
+	new_de_size = le16_to_cpu(new_de->size);
+	hdr_used = le32_to_cpu(hdr->used);
+	hdr_total = le32_to_cpu(hdr->total);
+	asize = le32_to_cpu(attr->size);
+	root_size = le32_to_cpu(attr->res.data_size);
+
+	ds_root = new_de_size + hdr_used - hdr_total;
+
+	if (used + ds_root < sbi->max_bytes_per_attr) {
+		/* make a room for new elements */
+		mi_resize_attr(mi, attr, ds_root);
+		hdr->total = cpu_to_le32(hdr_total + ds_root);
+		e = hdr_insert_de(indx, hdr, new_de, root_de, ctx);
+		WARN_ON(!e);
+		fnd_clear(fnd);
+		fnd->root_de = e;
+
+		return 0;
+	}
+
+	/* Make a copy of root attribute to restore if error */
+	a_root = ntfs_memdup(attr, asize);
+	if (!a_root) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	/* copy all the non-end entries from the index root to the new buffer.*/
+	to_move = 0;
+	e0 = hdr_first_de(hdr);
+
+	/* Calculate the size to copy */
+	for (e = e0;; e = hdr_next_de(hdr, e)) {
+		if (!e) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (de_is_last(e))
+			break;
+		to_move += le16_to_cpu(e->size);
+	}
+
+	n = NULL;
+	if (!to_move) {
+		re = NULL;
+	} else {
+		re = ntfs_memdup(e0, to_move);
+		if (!re) {
+			err = -ENOMEM;
+			goto out;
+		}
+	}
+
+	sub_vbn = NULL;
+	if (de_has_vcn(e)) {
+		t_vbn = de_get_vbn_le(e);
+		sub_vbn = &t_vbn;
+	}
+
+	new_root_size = sizeof(struct INDEX_ROOT) + sizeof(struct NTFS_DE) +
+			sizeof(u64);
+	ds_root = new_root_size - root_size;
+
+	if (ds_root > 0 && used + ds_root > sbi->max_bytes_per_attr) {
+		/* make root external */
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
+	if (ds_root)
+		mi_resize_attr(mi, attr, ds_root);
+
+	/* Fill first entry (vcn will be set later) */
+	e = (struct NTFS_DE *)(root + 1);
+	memset(e, 0, sizeof(struct NTFS_DE));
+	e->size = cpu_to_le16(sizeof(struct NTFS_DE) + sizeof(u64));
+	e->flags = NTFS_IE_HAS_SUBNODES | NTFS_IE_LAST;
+
+	hdr->flags = 1;
+	hdr->used = hdr->total =
+		cpu_to_le32(new_root_size - offsetof(struct INDEX_ROOT, ihdr));
+
+	fnd->root_de = hdr_first_de(hdr);
+	mi->dirty = true;
+
+	/* Create alloc and bitmap attributes (if not) */
+	err = run_is_empty(&indx->alloc_run)
+		      ? indx_create_allocate(indx, ni, &new_vbn)
+		      : indx_add_allocate(indx, ni, &new_vbn);
+
+	/* layout of record may be changed, so rescan root */
+	root = indx_get_root(indx, ni, &attr, &mi);
+	if (!root) {
+		/* bug? */
+		ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
+		err = -EINVAL;
+		goto out1;
+	}
+
+	if (err) {
+		/* restore root */
+		if (mi_resize_attr(mi, attr, -ds_root))
+			memcpy(attr, a_root, asize);
+		else {
+			/* bug? */
+			ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
+		}
+		goto out1;
+	}
+
+	e = (struct NTFS_DE *)(root + 1);
+	*(__le64 *)(e + 1) = cpu_to_le64(new_vbn);
+	mi->dirty = true;
+
+	/* now we can create/format the new buffer and copy the entries into */
+	n = indx_new(indx, ni, new_vbn, sub_vbn);
+	if (IS_ERR(n)) {
+		err = PTR_ERR(n);
+		goto out1;
+	}
+
+	hdr = &n->index->ihdr;
+	hdr_used = le32_to_cpu(hdr->used);
+	hdr_total = le32_to_cpu(hdr->total);
+
+	/* Copy root entries into new buffer */
+	hdr_insert_head(hdr, re, to_move);
+
+	/* Update bitmap attribute */
+	indx_mark_used(indx, ni, new_vbn >> indx->idx2vbn_bits);
+
+	/* Check if we can insert new entry new index buffer */
+	if (hdr_used + new_de_size > hdr_total) {
+		/*
+		 * This occurs if mft record is the same or bigger than index
+		 * buffer. Move all root new index and have no space to add
+		 * new entry classic case when mft record is 1K and index
+		 * buffer 4K the problem should not occurs
+		 */
+		ntfs_free(re);
+		indx_write(indx, ni, n, 0);
+
+		put_indx_node(n);
+		fnd_clear(fnd);
+		err = indx_insert_entry(indx, ni, new_de, ctx, fnd);
+		goto out;
+	}
+
+	/*
+	 * Now root is a parent for new index buffer
+	 * Insert NewEntry a new buffer
+	 */
+	e = hdr_insert_de(indx, hdr, new_de, NULL, ctx);
+	if (!e) {
+		err = -EINVAL;
+		goto out1;
+	}
+	fnd_push(fnd, n, e);
+
+	/* Just write updates index into disk */
+	indx_write(indx, ni, n, 0);
+
+	n = NULL;
+
+out1:
+	ntfs_free(re);
+	if (n)
+		put_indx_node(n);
+
+out:
+	ntfs_free(a_root);
+	return err;
+}
+
+/*
+ * indx_insert_into_buffer
+ *
+ * attempts to insert an entry into an Index Allocation Buffer.
+ * If necessary, it will split the buffer.
+ */
+static int
+indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
+			struct INDEX_ROOT *root, const struct NTFS_DE *new_de,
+			const void *ctx, int level, struct ntfs_fnd *fnd)
+{
+	int err;
+	const struct NTFS_DE *sp;
+	struct NTFS_DE *e, *de_t, *up_e = NULL;
+	struct indx_node *n2 = NULL;
+	struct indx_node *n1 = fnd->nodes[level];
+	struct INDEX_HDR *hdr1 = &n1->index->ihdr;
+	struct INDEX_HDR *hdr2;
+	u32 to_copy, used;
+	CLST new_vbn;
+	__le64 t_vbn, *sub_vbn;
+	u16 sp_size;
+
+	/* Try the most easy case */
+	e = fnd->level - 1 == level ? fnd->de[level] : NULL;
+	e = hdr_insert_de(indx, hdr1, new_de, e, ctx);
+	fnd->de[level] = e;
+	if (e) {
+		/* Just write updated index into disk */
+		indx_write(indx, ni, n1, 0);
+		return 0;
+	}
+
+	/*
+	 * No space to insert into buffer. Split it.
+	 * To split we:
+	 *  - Save split point ('cause index buffers will be changed)
+	 * - Allocate NewBuffer and copy all entries <= sp into new buffer
+	 * - Remove all entries (sp including) from TargetBuffer
+	 * - Insert NewEntry into left or right buffer (depending on sp <=>
+	 *     NewEntry)
+	 * - Insert sp into parent buffer (or root)
+	 * - Make sp a parent for new buffer
+	 */
+	sp = hdr_find_split(hdr1);
+	if (!sp)
+		return -EINVAL;
+
+	sp_size = le16_to_cpu(sp->size);
+	up_e = ntfs_malloc(sp_size + sizeof(u64));
+	if (!up_e)
+		return -ENOMEM;
+	memcpy(up_e, sp, sp_size);
+
+	if (!hdr1->flags) {
+		up_e->flags |= NTFS_IE_HAS_SUBNODES;
+		up_e->size = cpu_to_le16(sp_size + sizeof(u64));
+		sub_vbn = NULL;
+	} else {
+		t_vbn = de_get_vbn_le(up_e);
+		sub_vbn = &t_vbn;
+	}
+
+	/* Allocate on disk a new index allocation buffer. */
+	err = indx_add_allocate(indx, ni, &new_vbn);
+	if (err)
+		goto out;
+
+	/* Allocate and format memory a new index buffer */
+	n2 = indx_new(indx, ni, new_vbn, sub_vbn);
+	if (IS_ERR(n2)) {
+		err = PTR_ERR(n2);
+		goto out;
+	}
+
+	hdr2 = &n2->index->ihdr;
+
+	/* Make sp a parent for new buffer */
+	de_set_vbn(up_e, new_vbn);
+
+	/* copy all the entries <= sp into the new buffer. */
+	de_t = hdr_first_de(hdr1);
+	to_copy = PtrOffset(de_t, sp);
+	hdr_insert_head(hdr2, de_t, to_copy);
+
+	/* remove all entries (sp including) from hdr1 */
+	used = le32_to_cpu(hdr1->used) - to_copy - sp_size;
+	memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off));
+	hdr1->used = cpu_to_le32(used);
+
+	/* Insert new entry into left or right buffer (depending on sp <=> new_de) */
+	hdr_insert_de(indx,
+		      (*indx->cmp)(new_de + 1, le16_to_cpu(new_de->key_size),
+				   up_e + 1, le16_to_cpu(up_e->key_size),
+				   ctx) < 0
+			      ? hdr2
+			      : hdr1,
+		      new_de, NULL, ctx);
+
+	indx_mark_used(indx, ni, new_vbn >> indx->idx2vbn_bits);
+
+	indx_write(indx, ni, n1, 0);
+	indx_write(indx, ni, n2, 0);
+
+	put_indx_node(n2);
+
+	/*
+	 * we've finished splitting everybody, so we are ready to
+	 * insert the promoted entry into the parent.
+	 */
+	if (!level) {
+		/* Insert in root */
+		err = indx_insert_into_root(indx, ni, up_e, NULL, ctx, fnd);
+		if (err)
+			goto out;
+	} else {
+		/*
+		 * The target buffer's parent is another index buffer
+		 * TODO: Remove recursion
+		 */
+		err = indx_insert_into_buffer(indx, ni, root, up_e, ctx,
+					      level - 1, fnd);
+		if (err)
+			goto out;
+	}
+
+out:
+	ntfs_free(up_e);
+
+	return err;
+}
+
+/*
+ * indx_insert_entry
+ *
+ * inserts new entry into index
+ */
+int indx_insert_entry(struct ntfs_index *indx, struct ntfs_inode *ni,
+		      const struct NTFS_DE *new_de, const void *ctx,
+		      struct ntfs_fnd *fnd)
+{
+	int err;
+	int diff;
+	struct NTFS_DE *e;
+	struct ntfs_fnd *fnd_a = NULL;
+	struct INDEX_ROOT *root;
+
+	if (!fnd) {
+		fnd_a = fnd_get();
+		if (!fnd_a) {
+			err = -ENOMEM;
+			goto out1;
+		}
+		fnd = fnd_a;
+	}
+
+	root = indx_get_root(indx, ni, NULL, NULL);
+	if (!root) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (fnd_is_empty(fnd)) {
+		/* Find the spot the tree where we want to insert the new entry. */
+		err = indx_find(indx, ni, root, new_de + 1,
+				le16_to_cpu(new_de->key_size), ctx, &diff, &e,
+				fnd);
+		if (err)
+			goto out;
+
+		if (!diff) {
+			err = -EEXIST;
+			goto out;
+		}
+	}
+
+	if (!fnd->level) {
+		/* The root is also a leaf, so we'll insert the new entry into it. */
+		err = indx_insert_into_root(indx, ni, new_de, fnd->root_de, ctx,
+					    fnd);
+		if (err)
+			goto out;
+	} else {
+		/* found a leaf buffer, so we'll insert the new entry into it.*/
+		err = indx_insert_into_buffer(indx, ni, root, new_de, ctx,
+					      fnd->level - 1, fnd);
+		if (err)
+			goto out;
+	}
+
+out:
+	fnd_put(fnd_a);
+out1:
+	return err;
+}
+
+/*
+ * indx_find_buffer
+ *
+ * locates a buffer the tree.
+ */
+static struct indx_node *indx_find_buffer(struct ntfs_index *indx,
+					  struct ntfs_inode *ni,
+					  const struct INDEX_ROOT *root,
+					  __le64 vbn, struct indx_node *n)
+{
+	int err;
+	const struct NTFS_DE *e;
+	struct indx_node *r;
+	const struct INDEX_HDR *hdr = n ? &n->index->ihdr : &root->ihdr;
+
+	/* Step 1: Scan one level */
+	for (e = hdr_first_de(hdr);; e = hdr_next_de(hdr, e)) {
+		if (!e)
+			return ERR_PTR(-EINVAL);
+
+		if (de_has_vcn(e) && vbn == de_get_vbn_le(e))
+			return n;
+
+		if (de_is_last(e))
+			break;
+	}
+
+	/* Step2: Do recursion */
+	e = Add2Ptr(hdr, le32_to_cpu(hdr->de_off));
+	for (;;) {
+		if (de_has_vcn_ex(e)) {
+			err = indx_read(indx, ni, de_get_vbn(e), &n);
+			if (err)
+				return ERR_PTR(err);
+
+			r = indx_find_buffer(indx, ni, root, vbn, n);
+			if (r)
+				return r;
+		}
+
+		if (de_is_last(e))
+			break;
+
+		e = Add2Ptr(e, le16_to_cpu(e->size));
+	}
+
+	return NULL;
+}
+
+/*
+ * indx_shrink
+ *
+ * deallocates unused tail indexes
+ */
+static int indx_shrink(struct ntfs_index *indx, struct ntfs_inode *ni,
+		       size_t bit)
+{
+	int err = 0;
+	u64 bpb, new_data;
+	size_t nbits;
+	struct ATTRIB *b;
+	struct ATTR_LIST_ENTRY *le = NULL;
+	const struct INDEX_NAMES *in = &s_index_names[indx->type];
+
+	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
+			 NULL, NULL);
+
+	if (!b)
+		return -ENOENT;
+
+	if (!b->non_res) {
+		unsigned long pos;
+		const unsigned long *bm = resident_data(b);
+
+		nbits = le32_to_cpu(b->res.data_size) * 8;
+
+		if (bit >= nbits)
+			return 0;
+
+		pos = find_next_bit(bm, nbits, bit);
+		if (pos < nbits)
+			return 0;
+	} else {
+		size_t used = MINUS_ONE_T;
+
+		nbits = le64_to_cpu(b->nres.data_size) * 8;
+
+		if (bit >= nbits)
+			return 0;
+
+		err = scan_nres_bitmap(ni, b, indx, bit, &scan_for_used, &used);
+		if (err)
+			return err;
+
+		if (used != MINUS_ONE_T)
+			return 0;
+	}
+
+	new_data = (u64)bit << indx->index_bits;
+
+	err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
+			    &indx->alloc_run, new_data, &new_data, false, NULL);
+	if (err)
+		return err;
+
+	bpb = bitmap_size(bit);
+	if (bpb * 8 == nbits)
+		return 0;
+
+	err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
+			    &indx->bitmap_run, bpb, &bpb, false, NULL);
+
+	return err;
+}
+
+static int indx_free_children(struct ntfs_index *indx, struct ntfs_inode *ni,
+			      const struct NTFS_DE *e, bool trim)
+{
+	int err;
+	struct indx_node *n;
+	struct INDEX_HDR *hdr;
+	CLST vbn = de_get_vbn(e);
+	size_t i;
+
+	err = indx_read(indx, ni, vbn, &n);
+	if (err)
+		return err;
+
+	hdr = &n->index->ihdr;
+	/* First, recurse into the children, if any.*/
+	if (hdr_has_subnode(hdr)) {
+		for (e = hdr_first_de(hdr); e; e = hdr_next_de(hdr, e)) {
+			indx_free_children(indx, ni, e, false);
+			if (de_is_last(e))
+				break;
+		}
+	}
+
+	put_indx_node(n);
+
+	i = vbn >> indx->idx2vbn_bits;
+	/* We've gotten rid of the children; add this buffer to the free list. */
+	indx_mark_free(indx, ni, i);
+
+	if (!trim)
+		return 0;
+
+	/*
+	 * If there are no used indexes after current free index
+	 * then we can truncate allocation and bitmap
+	 * Use bitmap to estimate the case
+	 */
+	indx_shrink(indx, ni, i + 1);
+	return 0;
+}
+
+/*
+ * indx_get_entry_to_replace
+ *
+ * finds a replacement entry for a deleted entry
+ * always returns a node entry:
+ * NTFS_IE_HAS_SUBNODES is set the flags and the size includes the sub_vcn
+ */
+static int indx_get_entry_to_replace(struct ntfs_index *indx,
+				     struct ntfs_inode *ni,
+				     const struct NTFS_DE *de_next,
+				     struct NTFS_DE **de_to_replace,
+				     struct ntfs_fnd *fnd)
+{
+	int err;
+	int level = -1;
+	CLST vbn;
+	struct NTFS_DE *e, *te, *re;
+	struct indx_node *n;
+	struct INDEX_BUFFER *ib;
+
+	*de_to_replace = NULL;
+
+	/* Find first leaf entry down from de_next */
+	vbn = de_get_vbn(de_next);
+	for (;;) {
+		n = NULL;
+		err = indx_read(indx, ni, vbn, &n);
+		if (err)
+			goto out;
+
+		e = hdr_first_de(&n->index->ihdr);
+		fnd_push(fnd, n, e);
+
+		if (!de_is_last(e)) {
+			/*
+			 * This buffer is non-empty, so its first entry could be used as the
+			 * replacement entry.
+			 */
+			level = fnd->level - 1;
+		}
+
+		if (!de_has_vcn(e))
+			break;
+
+		/* This buffer is a node. Continue to go down */
+		vbn = de_get_vbn(e);
+	}
+
+	if (level == -1)
+		goto out;
+
+	n = fnd->nodes[level];
+	te = hdr_first_de(&n->index->ihdr);
+	/* Copy the candidate entry into the replacement entry buffer. */
+	re = ntfs_malloc(le16_to_cpu(te->size) + sizeof(u64));
+	if (!re) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	*de_to_replace = re;
+	memcpy(re, te, le16_to_cpu(te->size));
+
+	if (!de_has_vcn(re)) {
+		/*
+		 * The replacement entry we found doesn't have a sub_vcn. increase its size
+		 * to hold one.
+		 */
+		le16_add_cpu(&re->size, sizeof(u64));
+		re->flags |= NTFS_IE_HAS_SUBNODES;
+	} else {
+		/*
+		 * The replacement entry we found was a node entry, which means that all
+		 * its child buffers are empty. Return them to the free pool.
+		 */
+		indx_free_children(indx, ni, te, true);
+	}
+
+	/*
+	 * Expunge the replacement entry from its former location,
+	 * and then write that buffer.
+	 */
+	ib = n->index;
+	e = hdr_delete_de(&ib->ihdr, te);
+
+	fnd->de[level] = e;
+	indx_write(indx, ni, n, 0);
+
+	/* Check to see if this action created an empty leaf. */
+	if (ib_is_leaf(ib) && ib_is_empty(ib))
+		return 0;
+
+out:
+	fnd_clear(fnd);
+	return err;
+}
+
+/*
+ * indx_delete_entry
+ *
+ * deletes an entry from the index.
+ */
+int indx_delete_entry(struct ntfs_index *indx, struct ntfs_inode *ni,
+		      const void *key, u32 key_len, const void *ctx)
+{
+	int err, diff;
+	struct INDEX_ROOT *root;
+	struct INDEX_HDR *hdr;
+	struct ntfs_fnd *fnd, *fnd2;
+	struct INDEX_BUFFER *ib;
+	struct NTFS_DE *e, *re, *next, *prev, *me;
+	struct indx_node *n, *n2d = NULL;
+	__le64 sub_vbn;
+	int level, level2;
+	struct ATTRIB *attr;
+	struct mft_inode *mi;
+	u32 e_size, root_size, new_root_size;
+	size_t trim_bit;
+	const struct INDEX_NAMES *in;
+
+	fnd = fnd_get();
+	if (!fnd) {
+		err = -ENOMEM;
+		goto out2;
+	}
+
+	fnd2 = fnd_get();
+	if (!fnd2) {
+		err = -ENOMEM;
+		goto out1;
+	}
+
+	root = indx_get_root(indx, ni, &attr, &mi);
+	if (!root) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	/* Locate the entry to remove. */
+	err = indx_find(indx, ni, root, key, key_len, ctx, &diff, &e, fnd);
+	if (err)
+		goto out;
+
+	if (!e || diff) {
+		err = -ENOENT;
+		goto out;
+	}
+
+	level = fnd->level;
+
+	if (level) {
+		n = fnd->nodes[level - 1];
+		e = fnd->de[level - 1];
+		ib = n->index;
+		hdr = &ib->ihdr;
+	} else {
+		hdr = &root->ihdr;
+		e = fnd->root_de;
+		n = NULL;
+	}
+
+	e_size = le16_to_cpu(e->size);
+
+	if (!de_has_vcn_ex(e)) {
+		/* The entry to delete is a leaf, so we can just rip it out */
+		hdr_delete_de(hdr, e);
+
+		if (!level) {
+			hdr->total = hdr->used;
+
+			/* Shrink resident root attribute */
+			mi_resize_attr(mi, attr, 0 - e_size);
+			goto out;
+		}
+
+		indx_write(indx, ni, n, 0);
+
+		/*
+		 * Check to see if removing that entry made
+		 * the leaf empty.
+		 */
+		if (ib_is_leaf(ib) && ib_is_empty(ib)) {
+			fnd_pop(fnd);
+			fnd_push(fnd2, n, e);
+		}
+	} else {
+		/*
+		 * The entry we wish to delete is a node buffer, so we
+		 * have to find a replacement for it.
+		 */
+		next = de_get_next(e);
+
+		err = indx_get_entry_to_replace(indx, ni, next, &re, fnd2);
+		if (err)
+			goto out;
+
+		if (re) {
+			de_set_vbn_le(re, de_get_vbn_le(e));
+			hdr_delete_de(hdr, e);
+
+			err = level ? indx_insert_into_buffer(indx, ni, root,
+							      re, ctx,
+							      fnd->level - 1,
+							      fnd)
+				    : indx_insert_into_root(indx, ni, re, e,
+							    ctx, fnd);
+			ntfs_free(re);
+
+			if (err)
+				goto out;
+		} else {
+			/*
+			 * There is no replacement for the current entry.
+			 * This means that the subtree rooted at its node is empty,
+			 * and can be deleted, which turn means that the node can
+			 * just inherit the deleted entry sub_vcn
+			 */
+			indx_free_children(indx, ni, next, true);
+
+			de_set_vbn_le(next, de_get_vbn_le(e));
+			hdr_delete_de(hdr, e);
+			if (level) {
+				indx_write(indx, ni, n, 0);
+			} else {
+				hdr->total = hdr->used;
+
+				/* Shrink resident root attribute */
+				mi_resize_attr(mi, attr, 0 - e_size);
+			}
+		}
+	}
+
+	/* Delete a branch of tree */
+	if (!fnd2 || !fnd2->level)
+		goto out;
+
+	/* Reinit root 'cause it can be changed */
+	root = indx_get_root(indx, ni, &attr, &mi);
+	if (!root) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	n2d = NULL;
+	sub_vbn = fnd2->nodes[0]->index->vbn;
+	level2 = 0;
+	level = fnd->level;
+
+	hdr = level ? &fnd->nodes[level - 1]->index->ihdr : &root->ihdr;
+
+	/* Scan current level */
+	for (e = hdr_first_de(hdr);; e = hdr_next_de(hdr, e)) {
+		if (!e) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (de_has_vcn(e) && sub_vbn == de_get_vbn_le(e))
+			break;
+
+		if (de_is_last(e)) {
+			e = NULL;
+			break;
+		}
+	}
+
+	if (!e) {
+		/* Do slow search from root */
+		struct indx_node *in;
+
+		fnd_clear(fnd);
+
+		in = indx_find_buffer(indx, ni, root, sub_vbn, NULL);
+		if (IS_ERR(in)) {
+			err = PTR_ERR(in);
+			goto out;
+		}
+
+		if (in)
+			fnd_push(fnd, in, NULL);
+	}
+
+	/* Merge fnd2 -> fnd */
+	for (level = 0; level < fnd2->level; level++) {
+		fnd_push(fnd, fnd2->nodes[level], fnd2->de[level]);
+		fnd2->nodes[level] = NULL;
+	}
+	fnd2->level = 0;
+
+	hdr = NULL;
+	for (level = fnd->level; level; level--) {
+		struct indx_node *in = fnd->nodes[level - 1];
+
+		ib = in->index;
+		if (ib_is_empty(ib)) {
+			sub_vbn = ib->vbn;
+		} else {
+			hdr = &ib->ihdr;
+			n2d = in;
+			level2 = level;
+			break;
+		}
+	}
+
+	if (!hdr)
+		hdr = &root->ihdr;
+
+	e = hdr_first_de(hdr);
+	if (!e) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (hdr != &root->ihdr || !de_is_last(e)) {
+		prev = NULL;
+		while (!de_is_last(e)) {
+			if (de_has_vcn(e) && sub_vbn == de_get_vbn_le(e))
+				break;
+			prev = e;
+			e = hdr_next_de(hdr, e);
+			if (!e) {
+				err = -EINVAL;
+				goto out;
+			}
+		}
+
+		if (sub_vbn != de_get_vbn_le(e)) {
+			/*
+			 * Didn't find the parent entry, although this buffer is the parent trail.
+			 * Something is corrupt.
+			 */
+			err = -EINVAL;
+			goto out;
+		}
+
+		if (de_is_last(e)) {
+			/*
+			 * Since we can't remove the end entry, we'll remove its
+			 * predecessor instead. This means we have to transfer the
+			 * predecessor's sub_vcn to the end entry.
+			 * Note: that this index block is not empty, so the
+			 * predecessor must exist
+			 */
+			if (!prev) {
+				err = -EINVAL;
+				goto out;
+			}
+
+			if (de_has_vcn(prev)) {
+				de_set_vbn_le(e, de_get_vbn_le(prev));
+			} else if (de_has_vcn(e)) {
+				le16_sub_cpu(&e->size, sizeof(u64));
+				e->flags &= ~NTFS_IE_HAS_SUBNODES;
+				le32_sub_cpu(&hdr->used, sizeof(u64));
+			}
+			e = prev;
+		}
+
+		/*
+		 * Copy the current entry into a temporary buffer (stripping off its
+		 * down-pointer, if any) and delete it from the current buffer or root,
+		 * as appropriate.
+		 */
+		e_size = le16_to_cpu(e->size);
+		me = ntfs_memdup(e, e_size);
+		if (!me) {
+			err = -ENOMEM;
+			goto out;
+		}
+
+		if (de_has_vcn(me)) {
+			me->flags &= ~NTFS_IE_HAS_SUBNODES;
+			le16_sub_cpu(&me->size, sizeof(u64));
+		}
+
+		hdr_delete_de(hdr, e);
+
+		if (hdr == &root->ihdr) {
+			level = 0;
+			hdr->total = hdr->used;
+
+			/* Shrink resident root attribute */
+			mi_resize_attr(mi, attr, 0 - e_size);
+		} else {
+			indx_write(indx, ni, n2d, 0);
+			level = level2;
+		}
+
+		/* Mark unused buffers as free */
+		trim_bit = -1;
+		for (; level < fnd->level; level++) {
+			ib = fnd->nodes[level]->index;
+			if (ib_is_empty(ib)) {
+				size_t k = le64_to_cpu(ib->vbn) >>
+					   indx->idx2vbn_bits;
+
+				indx_mark_free(indx, ni, k);
+				if (k < trim_bit)
+					trim_bit = k;
+			}
+		}
+
+		fnd_clear(fnd);
+		/*fnd->root_de = NULL;*/
+
+		/*
+		 * Re-insert the entry into the tree.
+		 * Find the spot the tree where we want to insert the new entry.
+		 */
+		err = indx_insert_entry(indx, ni, me, ctx, fnd);
+		ntfs_free(me);
+		if (err)
+			goto out;
+
+		if (trim_bit != -1)
+			indx_shrink(indx, ni, trim_bit);
+	} else {
+		/*
+		 * This tree needs to be collapsed down to an empty root.
+		 * Recreate the index root as an empty leaf and free all the bits the
+		 * index allocation bitmap.
+		 */
+		fnd_clear(fnd);
+		fnd_clear(fnd2);
+
+		in = &s_index_names[indx->type];
+
+		err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
+				    &indx->alloc_run, 0, NULL, false, NULL);
+		err = ni_remove_attr(ni, ATTR_ALLOC, in->name, in->name_len,
+				     false, NULL);
+		run_close(&indx->alloc_run);
+
+		err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
+				    &indx->bitmap_run, 0, NULL, false, NULL);
+		err = ni_remove_attr(ni, ATTR_BITMAP, in->name, in->name_len,
+				     false, NULL);
+		run_close(&indx->bitmap_run);
+
+		root = indx_get_root(indx, ni, &attr, &mi);
+		if (!root) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		root_size = le32_to_cpu(attr->res.data_size);
+		new_root_size =
+			sizeof(struct INDEX_ROOT) + sizeof(struct NTFS_DE);
+
+		if (new_root_size != root_size &&
+		    !mi_resize_attr(mi, attr, new_root_size - root_size)) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		/* Fill first entry */
+		e = (struct NTFS_DE *)(root + 1);
+		e->ref.low = 0;
+		e->ref.high = 0;
+		e->ref.seq = 0;
+		e->size = cpu_to_le16(sizeof(struct NTFS_DE));
+		e->flags = NTFS_IE_LAST; // 0x02
+		e->key_size = 0;
+		e->res = 0;
+
+		hdr = &root->ihdr;
+		hdr->flags = 0;
+		hdr->used = hdr->total = cpu_to_le32(
+			new_root_size - offsetof(struct INDEX_ROOT, ihdr));
+		mi->dirty = true;
+	}
+
+out:
+	fnd_put(fnd2);
+out1:
+	fnd_put(fnd);
+out2:
+	return err;
+}
+
+/*
+ * Update duplicated information in directory entry
+ * 'dup' - info from MFT record
+ */
+int indx_update_dup(struct ntfs_inode *ni, struct ntfs_sb_info *sbi,
+		    const struct ATTR_FILE_NAME *fname,
+		    const struct NTFS_DUP_INFO *dup, int sync)
+{
+	int err, diff;
+	struct NTFS_DE *e = NULL;
+	struct ATTR_FILE_NAME *e_fname;
+	struct ntfs_fnd *fnd;
+	struct INDEX_ROOT *root;
+	struct mft_inode *mi;
+	struct ntfs_index *indx = &ni->dir;
+
+	fnd = fnd_get();
+	if (!fnd) {
+		err = -ENOMEM;
+		goto out1;
+	}
+
+	root = indx_get_root(indx, ni, NULL, &mi);
+	if (!root) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	/* Find entry in directory */
+	err = indx_find(indx, ni, root, fname, fname_full_size(fname), sbi,
+			&diff, &e, fnd);
+	if (err)
+		goto out;
+
+	if (!e) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (diff) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	e_fname = (struct ATTR_FILE_NAME *)(e + 1);
+
+	if (!memcmp(&e_fname->dup, dup, sizeof(*dup))) {
+		/* nothing to update in index! Try to avoid this call */
+		goto out;
+	}
+
+	memcpy(&e_fname->dup, dup, sizeof(*dup));
+
+	if (fnd->level) {
+		/* directory entry in index */
+		err = indx_write(indx, ni, fnd->nodes[fnd->level - 1], sync);
+	} else {
+		/* directory entry in directory MFT record */
+		mi->dirty = true;
+		if (sync)
+			err = mi_write(mi, 1);
+		else
+			mark_inode_dirty(&ni->vfs_inode);
+	}
+
+out:
+	fnd_put(fnd);
+
+out1:
+	return err;
+}