xref: /kernel/linux/linux-6.6/fs/ntfs3/fsntfs.c

// 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/kernel.h>
#include <linux/nls.h>

#include "debug.h"
#include "ntfs.h"
#include "ntfs_fs.h"

// clang-format off
const struct cpu_str NAME_MFT = {
	4, 0, { '$', 'M', 'F', 'T' },
};
const struct cpu_str NAME_MIRROR = {
	8, 0, { '$', 'M', 'F', 'T', 'M', 'i', 'r', 'r' },
};
const struct cpu_str NAME_LOGFILE = {
	8, 0, { '$', 'L', 'o', 'g', 'F', 'i', 'l', 'e' },
};
const struct cpu_str NAME_VOLUME = {
	7, 0, { '$', 'V', 'o', 'l', 'u', 'm', 'e' },
};
const struct cpu_str NAME_ATTRDEF = {
	8, 0, { '$', 'A', 't', 't', 'r', 'D', 'e', 'f' },
};
const struct cpu_str NAME_ROOT = {
	1, 0, { '.' },
};
const struct cpu_str NAME_BITMAP = {
	7, 0, { '$', 'B', 'i', 't', 'm', 'a', 'p' },
};
const struct cpu_str NAME_BOOT = {
	5, 0, { '$', 'B', 'o', 'o', 't' },
};
const struct cpu_str NAME_BADCLUS = {
	8, 0, { '$', 'B', 'a', 'd', 'C', 'l', 'u', 's' },
};
const struct cpu_str NAME_QUOTA = {
	6, 0, { '$', 'Q', 'u', 'o', 't', 'a' },
};
const struct cpu_str NAME_SECURE = {
	7, 0, { '$', 'S', 'e', 'c', 'u', 'r', 'e' },
};
const struct cpu_str NAME_UPCASE = {
	7, 0, { '$', 'U', 'p', 'C', 'a', 's', 'e' },
};
const struct cpu_str NAME_EXTEND = {
	7, 0, { '$', 'E', 'x', 't', 'e', 'n', 'd' },
};
const struct cpu_str NAME_OBJID = {
	6, 0, { '$', 'O', 'b', 'j', 'I', 'd' },
};
const struct cpu_str NAME_REPARSE = {
	8, 0, { '$', 'R', 'e', 'p', 'a', 'r', 's', 'e' },
};
const struct cpu_str NAME_USNJRNL = {
	8, 0, { '$', 'U', 's', 'n', 'J', 'r', 'n', 'l' },
};
const __le16 BAD_NAME[4] = {
	cpu_to_le16('$'), cpu_to_le16('B'), cpu_to_le16('a'), cpu_to_le16('d'),
};
const __le16 I30_NAME[4] = {
	cpu_to_le16('$'), cpu_to_le16('I'), cpu_to_le16('3'), cpu_to_le16('0'),
};
const __le16 SII_NAME[4] = {
	cpu_to_le16('$'), cpu_to_le16('S'), cpu_to_le16('I'), cpu_to_le16('I'),
};
const __le16 SDH_NAME[4] = {
	cpu_to_le16('$'), cpu_to_le16('S'), cpu_to_le16('D'), cpu_to_le16('H'),
};
const __le16 SDS_NAME[4] = {
	cpu_to_le16('$'), cpu_to_le16('S'), cpu_to_le16('D'), cpu_to_le16('S'),
};
const __le16 SO_NAME[2] = {
	cpu_to_le16('$'), cpu_to_le16('O'),
};
const __le16 SQ_NAME[2] = {
	cpu_to_le16('$'), cpu_to_le16('Q'),
};
const __le16 SR_NAME[2] = {
	cpu_to_le16('$'), cpu_to_le16('R'),
};

#ifdef CONFIG_NTFS3_LZX_XPRESS
const __le16 WOF_NAME[17] = {
	cpu_to_le16('W'), cpu_to_le16('o'), cpu_to_le16('f'), cpu_to_le16('C'),
	cpu_to_le16('o'), cpu_to_le16('m'), cpu_to_le16('p'), cpu_to_le16('r'),
	cpu_to_le16('e'), cpu_to_le16('s'), cpu_to_le16('s'), cpu_to_le16('e'),
	cpu_to_le16('d'), cpu_to_le16('D'), cpu_to_le16('a'), cpu_to_le16('t'),
	cpu_to_le16('a'),
};
#endif

static const __le16 CON_NAME[3] = {
	cpu_to_le16('C'), cpu_to_le16('O'), cpu_to_le16('N'),
};

static const __le16 NUL_NAME[3] = {
	cpu_to_le16('N'), cpu_to_le16('U'), cpu_to_le16('L'),
};

static const __le16 AUX_NAME[3] = {
	cpu_to_le16('A'), cpu_to_le16('U'), cpu_to_le16('X'),
};

static const __le16 PRN_NAME[3] = {
	cpu_to_le16('P'), cpu_to_le16('R'), cpu_to_le16('N'),
};

static const __le16 COM_NAME[3] = {
	cpu_to_le16('C'), cpu_to_le16('O'), cpu_to_le16('M'),
};

static const __le16 LPT_NAME[3] = {
	cpu_to_le16('L'), cpu_to_le16('P'), cpu_to_le16('T'),
};

// clang-format on

/*
 * ntfs_fix_pre_write - Insert fixups into @rhdr before writing to disk.
 */
bool ntfs_fix_pre_write(struct NTFS_RECORD_HEADER *rhdr, size_t bytes)
{
	u16 *fixup, *ptr;
	u16 sample;
	u16 fo = le16_to_cpu(rhdr->fix_off);
	u16 fn = le16_to_cpu(rhdr->fix_num);

	if ((fo & 1) || fo + fn * sizeof(short) > SECTOR_SIZE || !fn-- ||
	    fn * SECTOR_SIZE > bytes) {
		return false;
	}

	/* Get fixup pointer. */
	fixup = Add2Ptr(rhdr, fo);

	if (*fixup >= 0x7FFF)
		*fixup = 1;
	else
		*fixup += 1;

	sample = *fixup;

	ptr = Add2Ptr(rhdr, SECTOR_SIZE - sizeof(short));

	while (fn--) {
		*++fixup = *ptr;
		*ptr = sample;
		ptr += SECTOR_SIZE / sizeof(short);
	}
	return true;
}

/*
 * ntfs_fix_post_read - Remove fixups after reading from disk.
 *
 * Return: < 0 if error, 0 if ok, 1 if need to update fixups.
 */
int ntfs_fix_post_read(struct NTFS_RECORD_HEADER *rhdr, size_t bytes,
		       bool simple)
{
	int ret;
	u16 *fixup, *ptr;
	u16 sample, fo, fn;

	fo = le16_to_cpu(rhdr->fix_off);
	fn = simple ? ((bytes >> SECTOR_SHIFT) + 1) :
		      le16_to_cpu(rhdr->fix_num);

	/* Check errors. */
	if ((fo & 1) || fo + fn * sizeof(short) > SECTOR_SIZE || !fn-- ||
	    fn * SECTOR_SIZE > bytes) {
		return -E_NTFS_CORRUPT;
	}

	/* Get fixup pointer. */
	fixup = Add2Ptr(rhdr, fo);
	sample = *fixup;
	ptr = Add2Ptr(rhdr, SECTOR_SIZE - sizeof(short));
	ret = 0;

	while (fn--) {
		/* Test current word. */
		if (*ptr != sample) {
			/* Fixup does not match! Is it serious error? */
			ret = -E_NTFS_FIXUP;
		}

		/* Replace fixup. */
		*ptr = *++fixup;
		ptr += SECTOR_SIZE / sizeof(short);
	}

	return ret;
}

/*
 * ntfs_extend_init - Load $Extend file.
 */
int ntfs_extend_init(struct ntfs_sb_info *sbi)
{
	int err;
	struct super_block *sb = sbi->sb;
	struct inode *inode, *inode2;
	struct MFT_REF ref;

	if (sbi->volume.major_ver < 3) {
		ntfs_notice(sb, "Skip $Extend 'cause NTFS version");
		return 0;
	}

	ref.low = cpu_to_le32(MFT_REC_EXTEND);
	ref.high = 0;
	ref.seq = cpu_to_le16(MFT_REC_EXTEND);
	inode = ntfs_iget5(sb, &ref, &NAME_EXTEND);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		ntfs_err(sb, "Failed to load $Extend (%d).", err);
		inode = NULL;
		goto out;
	}

	/* If ntfs_iget5() reads from disk it never returns bad inode. */
	if (!S_ISDIR(inode->i_mode)) {
		err = -EINVAL;
		goto out;
	}

	/* Try to find $ObjId */
	inode2 = dir_search_u(inode, &NAME_OBJID, NULL);
	if (inode2 && !IS_ERR(inode2)) {
		if (is_bad_inode(inode2)) {
			iput(inode2);
		} else {
			sbi->objid.ni = ntfs_i(inode2);
			sbi->objid_no = inode2->i_ino;
		}
	}

	/* Try to find $Quota */
	inode2 = dir_search_u(inode, &NAME_QUOTA, NULL);
	if (inode2 && !IS_ERR(inode2)) {
		sbi->quota_no = inode2->i_ino;
		iput(inode2);
	}

	/* Try to find $Reparse */
	inode2 = dir_search_u(inode, &NAME_REPARSE, NULL);
	if (inode2 && !IS_ERR(inode2)) {
		sbi->reparse.ni = ntfs_i(inode2);
		sbi->reparse_no = inode2->i_ino;
	}

	/* Try to find $UsnJrnl */
	inode2 = dir_search_u(inode, &NAME_USNJRNL, NULL);
	if (inode2 && !IS_ERR(inode2)) {
		sbi->usn_jrnl_no = inode2->i_ino;
		iput(inode2);
	}

	err = 0;
out:
	iput(inode);
	return err;
}

int ntfs_loadlog_and_replay(struct ntfs_inode *ni, struct ntfs_sb_info *sbi)
{
	int err = 0;
	struct super_block *sb = sbi->sb;
	bool initialized = false;
	struct MFT_REF ref;
	struct inode *inode;

	/* Check for 4GB. */
	if (ni->vfs_inode.i_size >= 0x100000000ull) {
		ntfs_err(sb, "\x24LogFile is large than 4G.");
		err = -EINVAL;
		goto out;
	}

	sbi->flags |= NTFS_FLAGS_LOG_REPLAYING;

	ref.low = cpu_to_le32(MFT_REC_MFT);
	ref.high = 0;
	ref.seq = cpu_to_le16(1);

	inode = ntfs_iget5(sb, &ref, NULL);

	if (IS_ERR(inode))
		inode = NULL;

	if (!inode) {
		/* Try to use MFT copy. */
		u64 t64 = sbi->mft.lbo;

		sbi->mft.lbo = sbi->mft.lbo2;
		inode = ntfs_iget5(sb, &ref, NULL);
		sbi->mft.lbo = t64;
		if (IS_ERR(inode))
			inode = NULL;
	}

	if (!inode) {
		err = -EINVAL;
		ntfs_err(sb, "Failed to load $MFT.");
		goto out;
	}

	sbi->mft.ni = ntfs_i(inode);

	/* LogFile should not contains attribute list. */
	err = ni_load_all_mi(sbi->mft.ni);
	if (!err)
		err = log_replay(ni, &initialized);

	iput(inode);
	sbi->mft.ni = NULL;

	sync_blockdev(sb->s_bdev);
	invalidate_bdev(sb->s_bdev);

	if (sbi->flags & NTFS_FLAGS_NEED_REPLAY) {
		err = 0;
		goto out;
	}

	if (sb_rdonly(sb) || !initialized)
		goto out;

	/* Fill LogFile by '-1' if it is initialized. */
	err = ntfs_bio_fill_1(sbi, &ni->file.run);

out:
	sbi->flags &= ~NTFS_FLAGS_LOG_REPLAYING;

	return err;
}

/*
 * ntfs_look_for_free_space - Look for a free space in bitmap.
 */
int ntfs_look_for_free_space(struct ntfs_sb_info *sbi, CLST lcn, CLST len,
			     CLST *new_lcn, CLST *new_len,
			     enum ALLOCATE_OPT opt)
{
	int err;
	CLST alen;
	struct super_block *sb = sbi->sb;
	size_t alcn, zlen, zeroes, zlcn, zlen2, ztrim, new_zlen;
	struct wnd_bitmap *wnd = &sbi->used.bitmap;

	down_write_nested(&wnd->rw_lock, BITMAP_MUTEX_CLUSTERS);
	if (opt & ALLOCATE_MFT) {
		zlen = wnd_zone_len(wnd);

		if (!zlen) {
			err = ntfs_refresh_zone(sbi);
			if (err)
				goto up_write;

			zlen = wnd_zone_len(wnd);
		}

		if (!zlen) {
			ntfs_err(sbi->sb, "no free space to extend mft");
			err = -ENOSPC;
			goto up_write;
		}

		lcn = wnd_zone_bit(wnd);
		alen = min_t(CLST, len, zlen);

		wnd_zone_set(wnd, lcn + alen, zlen - alen);

		err = wnd_set_used(wnd, lcn, alen);
		if (err)
			goto up_write;

		alcn = lcn;
		goto space_found;
	}
	/*
	 * 'Cause cluster 0 is always used this value means that we should use
	 * cached value of 'next_free_lcn' to improve performance.
	 */
	if (!lcn)
		lcn = sbi->used.next_free_lcn;

	if (lcn >= wnd->nbits)
		lcn = 0;

	alen = wnd_find(wnd, len, lcn, BITMAP_FIND_MARK_AS_USED, &alcn);
	if (alen)
		goto space_found;

	/* Try to use clusters from MftZone. */
	zlen = wnd_zone_len(wnd);
	zeroes = wnd_zeroes(wnd);

	/* Check too big request */
	if (len > zeroes + zlen || zlen <= NTFS_MIN_MFT_ZONE) {
		err = -ENOSPC;
		goto up_write;
	}

	/* How many clusters to cat from zone. */
	zlcn = wnd_zone_bit(wnd);
	zlen2 = zlen >> 1;
	ztrim = clamp_val(len, zlen2, zlen);
	new_zlen = max_t(size_t, zlen - ztrim, NTFS_MIN_MFT_ZONE);

	wnd_zone_set(wnd, zlcn, new_zlen);

	/* Allocate continues clusters. */
	alen = wnd_find(wnd, len, 0,
			BITMAP_FIND_MARK_AS_USED | BITMAP_FIND_FULL, &alcn);
	if (!alen) {
		err = -ENOSPC;
		goto up_write;
	}

space_found:
	err = 0;
	*new_len = alen;
	*new_lcn = alcn;

	ntfs_unmap_meta(sb, alcn, alen);

	/* Set hint for next requests. */
	if (!(opt & ALLOCATE_MFT))
		sbi->used.next_free_lcn = alcn + alen;
up_write:
	up_write(&wnd->rw_lock);
	return err;
}

/*
 * ntfs_check_for_free_space
 *
 * Check if it is possible to allocate 'clen' clusters and 'mlen' Mft records
 */
bool ntfs_check_for_free_space(struct ntfs_sb_info *sbi, CLST clen, CLST mlen)
{
	size_t free, zlen, avail;
	struct wnd_bitmap *wnd;

	wnd = &sbi->used.bitmap;
	down_read_nested(&wnd->rw_lock, BITMAP_MUTEX_CLUSTERS);
	free = wnd_zeroes(wnd);
	zlen = min_t(size_t, NTFS_MIN_MFT_ZONE, wnd_zone_len(wnd));
	up_read(&wnd->rw_lock);

	if (free < zlen + clen)
		return false;

	avail = free - (zlen + clen);

	wnd = &sbi->mft.bitmap;
	down_read_nested(&wnd->rw_lock, BITMAP_MUTEX_MFT);
	free = wnd_zeroes(wnd);
	zlen = wnd_zone_len(wnd);
	up_read(&wnd->rw_lock);

	if (free >= zlen + mlen)
		return true;

	return avail >= bytes_to_cluster(sbi, mlen << sbi->record_bits);
}

/*
 * ntfs_extend_mft - Allocate additional MFT records.
 *
 * sbi->mft.bitmap is locked for write.
 *
 * NOTE: recursive:
 *	ntfs_look_free_mft ->
 *	ntfs_extend_mft ->
 *	attr_set_size ->
 *	ni_insert_nonresident ->
 *	ni_insert_attr ->
 *	ni_ins_attr_ext ->
 *	ntfs_look_free_mft ->
 *	ntfs_extend_mft
 *
 * To avoid recursive always allocate space for two new MFT records
 * see attrib.c: "at least two MFT to avoid recursive loop".
 */
static int ntfs_extend_mft(struct ntfs_sb_info *sbi)
{
	int err;
	struct ntfs_inode *ni = sbi->mft.ni;
	size_t new_mft_total;
	u64 new_mft_bytes, new_bitmap_bytes;
	struct ATTRIB *attr;
	struct wnd_bitmap *wnd = &sbi->mft.bitmap;

	new_mft_total = ALIGN(wnd->nbits + NTFS_MFT_INCREASE_STEP, 128);
	new_mft_bytes = (u64)new_mft_total << sbi->record_bits;

	/* Step 1: Resize $MFT::DATA. */
	down_write(&ni->file.run_lock);
	err = attr_set_size(ni, ATTR_DATA, NULL, 0, &ni->file.run,
			    new_mft_bytes, NULL, false, &attr);

	if (err) {
		up_write(&ni->file.run_lock);
		goto out;
	}

	attr->nres.valid_size = attr->nres.data_size;
	new_mft_total = le64_to_cpu(attr->nres.alloc_size) >> sbi->record_bits;
	ni->mi.dirty = true;

	/* Step 2: Resize $MFT::BITMAP. */
	new_bitmap_bytes = bitmap_size(new_mft_total);

	err = attr_set_size(ni, ATTR_BITMAP, NULL, 0, &sbi->mft.bitmap.run,
			    new_bitmap_bytes, &new_bitmap_bytes, true, NULL);

	/* Refresh MFT Zone if necessary. */
	down_write_nested(&sbi->used.bitmap.rw_lock, BITMAP_MUTEX_CLUSTERS);

	ntfs_refresh_zone(sbi);

	up_write(&sbi->used.bitmap.rw_lock);
	up_write(&ni->file.run_lock);

	if (err)
		goto out;

	err = wnd_extend(wnd, new_mft_total);

	if (err)
		goto out;

	ntfs_clear_mft_tail(sbi, sbi->mft.used, new_mft_total);

	err = _ni_write_inode(&ni->vfs_inode, 0);
out:
	return err;
}

/*
 * ntfs_look_free_mft - Look for a free MFT record.
 */
int ntfs_look_free_mft(struct ntfs_sb_info *sbi, CLST *rno, bool mft,
		       struct ntfs_inode *ni, struct mft_inode **mi)
{
	int err = 0;
	size_t zbit, zlen, from, to, fr;
	size_t mft_total;
	struct MFT_REF ref;
	struct super_block *sb = sbi->sb;
	struct wnd_bitmap *wnd = &sbi->mft.bitmap;
	u32 ir;

	static_assert(sizeof(sbi->mft.reserved_bitmap) * 8 >=
		      MFT_REC_FREE - MFT_REC_RESERVED);

	if (!mft)
		down_write_nested(&wnd->rw_lock, BITMAP_MUTEX_MFT);

	zlen = wnd_zone_len(wnd);

	/* Always reserve space for MFT. */
	if (zlen) {
		if (mft) {
			zbit = wnd_zone_bit(wnd);
			*rno = zbit;
			wnd_zone_set(wnd, zbit + 1, zlen - 1);
		}
		goto found;
	}

	/* No MFT zone. Find the nearest to '0' free MFT. */
	if (!wnd_find(wnd, 1, MFT_REC_FREE, 0, &zbit)) {
		/* Resize MFT */
		mft_total = wnd->nbits;

		err = ntfs_extend_mft(sbi);
		if (!err) {
			zbit = mft_total;
			goto reserve_mft;
		}

		if (!mft || MFT_REC_FREE == sbi->mft.next_reserved)
			goto out;

		err = 0;

		/*
		 * Look for free record reserved area [11-16) ==
		 * [MFT_REC_RESERVED, MFT_REC_FREE ) MFT bitmap always
		 * marks it as used.
		 */
		if (!sbi->mft.reserved_bitmap) {
			/* Once per session create internal bitmap for 5 bits. */
			sbi->mft.reserved_bitmap = 0xFF;

			ref.high = 0;
			for (ir = MFT_REC_RESERVED; ir < MFT_REC_FREE; ir++) {
				struct inode *i;
				struct ntfs_inode *ni;
				struct MFT_REC *mrec;

				ref.low = cpu_to_le32(ir);
				ref.seq = cpu_to_le16(ir);

				i = ntfs_iget5(sb, &ref, NULL);
				if (IS_ERR(i)) {
next:
					ntfs_notice(
						sb,
						"Invalid reserved record %x",
						ref.low);
					continue;
				}
				if (is_bad_inode(i)) {
					iput(i);
					goto next;
				}

				ni = ntfs_i(i);

				mrec = ni->mi.mrec;

				if (!is_rec_base(mrec))
					goto next;

				if (mrec->hard_links)
					goto next;

				if (!ni_std(ni))
					goto next;

				if (ni_find_attr(ni, NULL, NULL, ATTR_NAME,
						 NULL, 0, NULL, NULL))
					goto next;

				__clear_bit(ir - MFT_REC_RESERVED,
					    &sbi->mft.reserved_bitmap);
			}
		}

		/* Scan 5 bits for zero. Bit 0 == MFT_REC_RESERVED */
		zbit = find_next_zero_bit(&sbi->mft.reserved_bitmap,
					  MFT_REC_FREE, MFT_REC_RESERVED);
		if (zbit >= MFT_REC_FREE) {
			sbi->mft.next_reserved = MFT_REC_FREE;
			goto out;
		}

		zlen = 1;
		sbi->mft.next_reserved = zbit;
	} else {
reserve_mft:
		zlen = zbit == MFT_REC_FREE ? (MFT_REC_USER - MFT_REC_FREE) : 4;
		if (zbit + zlen > wnd->nbits)
			zlen = wnd->nbits - zbit;

		while (zlen > 1 && !wnd_is_free(wnd, zbit, zlen))
			zlen -= 1;

		/* [zbit, zbit + zlen) will be used for MFT itself. */
		from = sbi->mft.used;
		if (from < zbit)
			from = zbit;
		to = zbit + zlen;
		if (from < to) {
			ntfs_clear_mft_tail(sbi, from, to);
			sbi->mft.used = to;
		}
	}

	if (mft) {
		*rno = zbit;
		zbit += 1;
		zlen -= 1;
	}

	wnd_zone_set(wnd, zbit, zlen);

found:
	if (!mft) {
		/* The request to get record for general purpose. */
		if (sbi->mft.next_free < MFT_REC_USER)
			sbi->mft.next_free = MFT_REC_USER;

		for (;;) {
			if (sbi->mft.next_free >= sbi->mft.bitmap.nbits) {
			} else if (!wnd_find(wnd, 1, MFT_REC_USER, 0, &fr)) {
				sbi->mft.next_free = sbi->mft.bitmap.nbits;
			} else {
				*rno = fr;
				sbi->mft.next_free = *rno + 1;
				break;
			}

			err = ntfs_extend_mft(sbi);
			if (err)
				goto out;
		}
	}

	if (ni && !ni_add_subrecord(ni, *rno, mi)) {
		err = -ENOMEM;
		goto out;
	}

	/* We have found a record that are not reserved for next MFT. */
	if (*rno >= MFT_REC_FREE)
		wnd_set_used(wnd, *rno, 1);
	else if (*rno >= MFT_REC_RESERVED && sbi->mft.reserved_bitmap_inited)
		__set_bit(*rno - MFT_REC_RESERVED, &sbi->mft.reserved_bitmap);

out:
	if (!mft)
		up_write(&wnd->rw_lock);

	return err;
}

/*
 * ntfs_mark_rec_free - Mark record as free.
 * is_mft - true if we are changing MFT
 */
void ntfs_mark_rec_free(struct ntfs_sb_info *sbi, CLST rno, bool is_mft)
{
	struct wnd_bitmap *wnd = &sbi->mft.bitmap;

	if (!is_mft)
		down_write_nested(&wnd->rw_lock, BITMAP_MUTEX_MFT);
	if (rno >= wnd->nbits)
		goto out;

	if (rno >= MFT_REC_FREE) {
		if (!wnd_is_used(wnd, rno, 1))
			ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
		else
			wnd_set_free(wnd, rno, 1);
	} else if (rno >= MFT_REC_RESERVED && sbi->mft.reserved_bitmap_inited) {
		__clear_bit(rno - MFT_REC_RESERVED, &sbi->mft.reserved_bitmap);
	}

	if (rno < wnd_zone_bit(wnd))
		wnd_zone_set(wnd, rno, 1);
	else if (rno < sbi->mft.next_free && rno >= MFT_REC_USER)
		sbi->mft.next_free = rno;

out:
	if (!is_mft)
		up_write(&wnd->rw_lock);
}

/*
 * ntfs_clear_mft_tail - Format empty records [from, to).
 *
 * sbi->mft.bitmap is locked for write.
 */
int ntfs_clear_mft_tail(struct ntfs_sb_info *sbi, size_t from, size_t to)
{
	int err;
	u32 rs;
	u64 vbo;
	struct runs_tree *run;
	struct ntfs_inode *ni;

	if (from >= to)
		return 0;

	rs = sbi->record_size;
	ni = sbi->mft.ni;
	run = &ni->file.run;

	down_read(&ni->file.run_lock);
	vbo = (u64)from * rs;
	for (; from < to; from++, vbo += rs) {
		struct ntfs_buffers nb;

		err = ntfs_get_bh(sbi, run, vbo, rs, &nb);
		if (err)
			goto out;

		err = ntfs_write_bh(sbi, &sbi->new_rec->rhdr, &nb, 0);
		nb_put(&nb);
		if (err)
			goto out;
	}

out:
	sbi->mft.used = from;
	up_read(&ni->file.run_lock);
	return err;
}

/*
 * ntfs_refresh_zone - Refresh MFT zone.
 *
 * sbi->used.bitmap is locked for rw.
 * sbi->mft.bitmap is locked for write.
 * sbi->mft.ni->file.run_lock for write.
 */
int ntfs_refresh_zone(struct ntfs_sb_info *sbi)
{
	CLST lcn, vcn, len;
	size_t lcn_s, zlen;
	struct wnd_bitmap *wnd = &sbi->used.bitmap;
	struct ntfs_inode *ni = sbi->mft.ni;

	/* Do not change anything unless we have non empty MFT zone. */
	if (wnd_zone_len(wnd))
		return 0;

	vcn = bytes_to_cluster(sbi,
			       (u64)sbi->mft.bitmap.nbits << sbi->record_bits);

	if (!run_lookup_entry(&ni->file.run, vcn - 1, &lcn, &len, NULL))
		lcn = SPARSE_LCN;

	/* We should always find Last Lcn for MFT. */
	if (lcn == SPARSE_LCN)
		return -EINVAL;

	lcn_s = lcn + 1;

	/* Try to allocate clusters after last MFT run. */
	zlen = wnd_find(wnd, sbi->zone_max, lcn_s, 0, &lcn_s);
	wnd_zone_set(wnd, lcn_s, zlen);

	return 0;
}

/*
 * ntfs_update_mftmirr - Update $MFTMirr data.
 */
void ntfs_update_mftmirr(struct ntfs_sb_info *sbi, int wait)
{
	int err;
	struct super_block *sb = sbi->sb;
	u32 blocksize, bytes;
	sector_t block1, block2;

	/*
	 * sb can be NULL here. In this case sbi->flags should be 0 too.
	 */
	if (!sb || !(sbi->flags & NTFS_FLAGS_MFTMIRR) ||
	    unlikely(ntfs3_forced_shutdown(sb)))
		return;

	blocksize = sb->s_blocksize;
	bytes = sbi->mft.recs_mirr << sbi->record_bits;
	block1 = sbi->mft.lbo >> sb->s_blocksize_bits;
	block2 = sbi->mft.lbo2 >> sb->s_blocksize_bits;

	for (; bytes >= blocksize; bytes -= blocksize) {
		struct buffer_head *bh1, *bh2;

		bh1 = sb_bread(sb, block1++);
		if (!bh1)
			return;

		bh2 = sb_getblk(sb, block2++);
		if (!bh2) {
			put_bh(bh1);
			return;
		}

		if (buffer_locked(bh2))
			__wait_on_buffer(bh2);

		lock_buffer(bh2);
		memcpy(bh2->b_data, bh1->b_data, blocksize);
		set_buffer_uptodate(bh2);
		mark_buffer_dirty(bh2);
		unlock_buffer(bh2);

		put_bh(bh1);
		bh1 = NULL;

		err = wait ? sync_dirty_buffer(bh2) : 0;

		put_bh(bh2);
		if (err)
			return;
	}

	sbi->flags &= ~NTFS_FLAGS_MFTMIRR;
}

/*
 * ntfs_bad_inode
 *
 * Marks inode as bad and marks fs as 'dirty'
 */
void ntfs_bad_inode(struct inode *inode, const char *hint)
{
	struct ntfs_sb_info *sbi = inode->i_sb->s_fs_info;

	ntfs_inode_err(inode, "%s", hint);
	make_bad_inode(inode);
	ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
}

/*
 * ntfs_set_state
 *
 * Mount: ntfs_set_state(NTFS_DIRTY_DIRTY)
 * Umount: ntfs_set_state(NTFS_DIRTY_CLEAR)
 * NTFS error: ntfs_set_state(NTFS_DIRTY_ERROR)
 */
int ntfs_set_state(struct ntfs_sb_info *sbi, enum NTFS_DIRTY_FLAGS dirty)
{
	int err;
	struct ATTRIB *attr;
	struct VOLUME_INFO *info;
	struct mft_inode *mi;
	struct ntfs_inode *ni;
	__le16 info_flags;

	/*
	 * Do not change state if fs was real_dirty.
	 * Do not change state if fs already dirty(clear).
	 * Do not change any thing if mounted read only.
	 */
	if (sbi->volume.real_dirty || sb_rdonly(sbi->sb))
		return 0;

	/* Check cached value. */
	if ((dirty == NTFS_DIRTY_CLEAR ? 0 : VOLUME_FLAG_DIRTY) ==
	    (sbi->volume.flags & VOLUME_FLAG_DIRTY))
		return 0;

	ni = sbi->volume.ni;
	if (!ni)
		return -EINVAL;

	mutex_lock_nested(&ni->ni_lock, NTFS_INODE_MUTEX_DIRTY);

	attr = ni_find_attr(ni, NULL, NULL, ATTR_VOL_INFO, NULL, 0, NULL, &mi);
	if (!attr) {
		err = -EINVAL;
		goto out;
	}

	info = resident_data_ex(attr, SIZEOF_ATTRIBUTE_VOLUME_INFO);
	if (!info) {
		err = -EINVAL;
		goto out;
	}

	info_flags = info->flags;

	switch (dirty) {
	case NTFS_DIRTY_ERROR:
		ntfs_notice(sbi->sb, "Mark volume as dirty due to NTFS errors");
		sbi->volume.real_dirty = true;
		fallthrough;
	case NTFS_DIRTY_DIRTY:
		info->flags |= VOLUME_FLAG_DIRTY;
		break;
	case NTFS_DIRTY_CLEAR:
		info->flags &= ~VOLUME_FLAG_DIRTY;
		break;
	}
	/* Cache current volume flags. */
	if (info_flags != info->flags) {
		sbi->volume.flags = info->flags;
		mi->dirty = true;
	}
	err = 0;

out:
	ni_unlock(ni);
	if (err)
		return err;

	mark_inode_dirty_sync(&ni->vfs_inode);
	/* verify(!ntfs_update_mftmirr()); */

	/* write mft record on disk. */
	err = _ni_write_inode(&ni->vfs_inode, 1);

	return err;
}

/*
 * security_hash - Calculates a hash of security descriptor.
 */
static inline __le32 security_hash(const void *sd, size_t bytes)
{
	u32 hash = 0;
	const __le32 *ptr = sd;

	bytes >>= 2;
	while (bytes--)
		hash = ((hash >> 0x1D) | (hash << 3)) + le32_to_cpu(*ptr++);
	return cpu_to_le32(hash);
}

/*
 * simple wrapper for sb_bread_unmovable.
 */
struct buffer_head *ntfs_bread(struct super_block *sb, sector_t block)
{
	struct ntfs_sb_info *sbi = sb->s_fs_info;
	struct buffer_head *bh;

	if (unlikely(block >= sbi->volume.blocks)) {
		/* prevent generic message "attempt to access beyond end of device" */
		ntfs_err(sb, "try to read out of volume at offset 0x%llx",
			 (u64)block << sb->s_blocksize_bits);
		return NULL;
	}

	bh = sb_bread_unmovable(sb, block);
	if (bh)
		return bh;

	ntfs_err(sb, "failed to read volume at offset 0x%llx",
		 (u64)block << sb->s_blocksize_bits);
	return NULL;
}

int ntfs_sb_read(struct super_block *sb, u64 lbo, size_t bytes, void *buffer)
{
	struct block_device *bdev = sb->s_bdev;
	u32 blocksize = sb->s_blocksize;
	u64 block = lbo >> sb->s_blocksize_bits;
	u32 off = lbo & (blocksize - 1);
	u32 op = blocksize - off;

	for (; bytes; block += 1, off = 0, op = blocksize) {
		struct buffer_head *bh = __bread(bdev, block, blocksize);

		if (!bh)
			return -EIO;

		if (op > bytes)
			op = bytes;

		memcpy(buffer, bh->b_data + off, op);

		put_bh(bh);

		bytes -= op;
		buffer = Add2Ptr(buffer, op);
	}

	return 0;
}

int ntfs_sb_write(struct super_block *sb, u64 lbo, size_t bytes,
		  const void *buf, int wait)
{
	u32 blocksize = sb->s_blocksize;
	struct block_device *bdev = sb->s_bdev;
	sector_t block = lbo >> sb->s_blocksize_bits;
	u32 off = lbo & (blocksize - 1);
	u32 op = blocksize - off;
	struct buffer_head *bh;

	if (!wait && (sb->s_flags & SB_SYNCHRONOUS))
		wait = 1;

	for (; bytes; block += 1, off = 0, op = blocksize) {
		if (op > bytes)
			op = bytes;

		if (op < blocksize) {
			bh = __bread(bdev, block, blocksize);
			if (!bh) {
				ntfs_err(sb, "failed to read block %llx",
					 (u64)block);
				return -EIO;
			}
		} else {
			bh = __getblk(bdev, block, blocksize);
			if (!bh)
				return -ENOMEM;
		}

		if (buffer_locked(bh))
			__wait_on_buffer(bh);

		lock_buffer(bh);
		if (buf) {
			memcpy(bh->b_data + off, buf, op);
			buf = Add2Ptr(buf, op);
		} else {
			memset(bh->b_data + off, -1, op);
		}

		set_buffer_uptodate(bh);
		mark_buffer_dirty(bh);
		unlock_buffer(bh);

		if (wait) {
			int err = sync_dirty_buffer(bh);

			if (err) {
				ntfs_err(
					sb,
					"failed to sync buffer at block %llx, error %d",
					(u64)block, err);
				put_bh(bh);
				return err;
			}
		}

		put_bh(bh);

		bytes -= op;
	}
	return 0;
}

int ntfs_sb_write_run(struct ntfs_sb_info *sbi, const struct runs_tree *run,
		      u64 vbo, const void *buf, size_t bytes, int sync)
{
	struct super_block *sb = sbi->sb;
	u8 cluster_bits = sbi->cluster_bits;
	u32 off = vbo & sbi->cluster_mask;
	CLST lcn, clen, vcn = vbo >> cluster_bits, vcn_next;
	u64 lbo, len;
	size_t idx;

	if (!run_lookup_entry(run, vcn, &lcn, &clen, &idx))
		return -ENOENT;

	if (lcn == SPARSE_LCN)
		return -EINVAL;

	lbo = ((u64)lcn << cluster_bits) + off;
	len = ((u64)clen << cluster_bits) - off;

	for (;;) {
		u32 op = min_t(u64, len, bytes);
		int err = ntfs_sb_write(sb, lbo, op, buf, sync);

		if (err)
			return err;

		bytes -= op;
		if (!bytes)
			break;

		vcn_next = vcn + clen;
		if (!run_get_entry(run, ++idx, &vcn, &lcn, &clen) ||
		    vcn != vcn_next)
			return -ENOENT;

		if (lcn == SPARSE_LCN)
			return -EINVAL;

		if (buf)
			buf = Add2Ptr(buf, op);

		lbo = ((u64)lcn << cluster_bits);
		len = ((u64)clen << cluster_bits);
	}

	return 0;
}

struct buffer_head *ntfs_bread_run(struct ntfs_sb_info *sbi,
				   const struct runs_tree *run, u64 vbo)
{
	struct super_block *sb = sbi->sb;
	u8 cluster_bits = sbi->cluster_bits;
	CLST lcn;
	u64 lbo;

	if (!run_lookup_entry(run, vbo >> cluster_bits, &lcn, NULL, NULL))
		return ERR_PTR(-ENOENT);

	lbo = ((u64)lcn << cluster_bits) + (vbo & sbi->cluster_mask);

	return ntfs_bread(sb, lbo >> sb->s_blocksize_bits);
}

int ntfs_read_run_nb(struct ntfs_sb_info *sbi, const struct runs_tree *run,
		     u64 vbo, void *buf, u32 bytes, struct ntfs_buffers *nb)
{
	int err;
	struct super_block *sb = sbi->sb;
	u32 blocksize = sb->s_blocksize;
	u8 cluster_bits = sbi->cluster_bits;
	u32 off = vbo & sbi->cluster_mask;
	u32 nbh = 0;
	CLST vcn_next, vcn = vbo >> cluster_bits;
	CLST lcn, clen;
	u64 lbo, len;
	size_t idx;
	struct buffer_head *bh;

	if (!run) {
		/* First reading of $Volume + $MFTMirr + $LogFile goes here. */
		if (vbo > MFT_REC_VOL * sbi->record_size) {
			err = -ENOENT;
			goto out;
		}

		/* Use absolute boot's 'MFTCluster' to read record. */
		lbo = vbo + sbi->mft.lbo;
		len = sbi->record_size;
	} else if (!run_lookup_entry(run, vcn, &lcn, &clen, &idx)) {
		err = -ENOENT;
		goto out;
	} else {
		if (lcn == SPARSE_LCN) {
			err = -EINVAL;
			goto out;
		}

		lbo = ((u64)lcn << cluster_bits) + off;
		len = ((u64)clen << cluster_bits) - off;
	}

	off = lbo & (blocksize - 1);
	if (nb) {
		nb->off = off;
		nb->bytes = bytes;
	}

	for (;;) {
		u32 len32 = len >= bytes ? bytes : len;
		sector_t block = lbo >> sb->s_blocksize_bits;

		do {
			u32 op = blocksize - off;

			if (op > len32)
				op = len32;

			bh = ntfs_bread(sb, block);
			if (!bh) {
				err = -EIO;
				goto out;
			}

			if (buf) {
				memcpy(buf, bh->b_data + off, op);
				buf = Add2Ptr(buf, op);
			}

			if (!nb) {
				put_bh(bh);
			} else if (nbh >= ARRAY_SIZE(nb->bh)) {
				err = -EINVAL;
				goto out;
			} else {
				nb->bh[nbh++] = bh;
				nb->nbufs = nbh;
			}

			bytes -= op;
			if (!bytes)
				return 0;
			len32 -= op;
			block += 1;
			off = 0;

		} while (len32);

		vcn_next = vcn + clen;
		if (!run_get_entry(run, ++idx, &vcn, &lcn, &clen) ||
		    vcn != vcn_next) {
			err = -ENOENT;
			goto out;
		}

		if (lcn == SPARSE_LCN) {
			err = -EINVAL;
			goto out;
		}

		lbo = ((u64)lcn << cluster_bits);
		len = ((u64)clen << cluster_bits);
	}

out:
	if (!nbh)
		return err;

	while (nbh) {
		put_bh(nb->bh[--nbh]);
		nb->bh[nbh] = NULL;
	}

	nb->nbufs = 0;
	return err;
}

/*
 * ntfs_read_bh
 *
 * Return: < 0 if error, 0 if ok, -E_NTFS_FIXUP if need to update fixups.
 */
int ntfs_read_bh(struct ntfs_sb_info *sbi, const struct runs_tree *run, u64 vbo,
		 struct NTFS_RECORD_HEADER *rhdr, u32 bytes,
		 struct ntfs_buffers *nb)
{
	int err = ntfs_read_run_nb(sbi, run, vbo, rhdr, bytes, nb);

	if (err)
		return err;
	return ntfs_fix_post_read(rhdr, nb->bytes, true);
}

int ntfs_get_bh(struct ntfs_sb_info *sbi, const struct runs_tree *run, u64 vbo,
		u32 bytes, struct ntfs_buffers *nb)
{
	int err = 0;
	struct super_block *sb = sbi->sb;
	u32 blocksize = sb->s_blocksize;
	u8 cluster_bits = sbi->cluster_bits;
	CLST vcn_next, vcn = vbo >> cluster_bits;
	u32 off;
	u32 nbh = 0;
	CLST lcn, clen;
	u64 lbo, len;
	size_t idx;

	nb->bytes = bytes;

	if (!run_lookup_entry(run, vcn, &lcn, &clen, &idx)) {
		err = -ENOENT;
		goto out;
	}

	off = vbo & sbi->cluster_mask;
	lbo = ((u64)lcn << cluster_bits) + off;
	len = ((u64)clen << cluster_bits) - off;

	nb->off = off = lbo & (blocksize - 1);

	for (;;) {
		u32 len32 = min_t(u64, len, bytes);
		sector_t block = lbo >> sb->s_blocksize_bits;

		do {
			u32 op;
			struct buffer_head *bh;

			if (nbh >= ARRAY_SIZE(nb->bh)) {
				err = -EINVAL;
				goto out;
			}

			op = blocksize - off;
			if (op > len32)
				op = len32;

			if (op == blocksize) {
				bh = sb_getblk(sb, block);
				if (!bh) {
					err = -ENOMEM;
					goto out;
				}
				if (buffer_locked(bh))
					__wait_on_buffer(bh);
				set_buffer_uptodate(bh);
			} else {
				bh = ntfs_bread(sb, block);
				if (!bh) {
					err = -EIO;
					goto out;
				}
			}

			nb->bh[nbh++] = bh;
			bytes -= op;
			if (!bytes) {
				nb->nbufs = nbh;
				return 0;
			}

			block += 1;
			len32 -= op;
			off = 0;
		} while (len32);

		vcn_next = vcn + clen;
		if (!run_get_entry(run, ++idx, &vcn, &lcn, &clen) ||
		    vcn != vcn_next) {
			err = -ENOENT;
			goto out;
		}

		lbo = ((u64)lcn << cluster_bits);
		len = ((u64)clen << cluster_bits);
	}

out:
	while (nbh) {
		put_bh(nb->bh[--nbh]);
		nb->bh[nbh] = NULL;
	}

	nb->nbufs = 0;

	return err;
}

int ntfs_write_bh(struct ntfs_sb_info *sbi, struct NTFS_RECORD_HEADER *rhdr,
		  struct ntfs_buffers *nb, int sync)
{
	int err = 0;
	struct super_block *sb = sbi->sb;
	u32 block_size = sb->s_blocksize;
	u32 bytes = nb->bytes;
	u32 off = nb->off;
	u16 fo = le16_to_cpu(rhdr->fix_off);
	u16 fn = le16_to_cpu(rhdr->fix_num);
	u32 idx;
	__le16 *fixup;
	__le16 sample;

	if ((fo & 1) || fo + fn * sizeof(short) > SECTOR_SIZE || !fn-- ||
	    fn * SECTOR_SIZE > bytes) {
		return -EINVAL;
	}

	for (idx = 0; bytes && idx < nb->nbufs; idx += 1, off = 0) {
		u32 op = block_size - off;
		char *bh_data;
		struct buffer_head *bh = nb->bh[idx];
		__le16 *ptr, *end_data;

		if (op > bytes)
			op = bytes;

		if (buffer_locked(bh))
			__wait_on_buffer(bh);

		lock_buffer(bh);

		bh_data = bh->b_data + off;
		end_data = Add2Ptr(bh_data, op);
		memcpy(bh_data, rhdr, op);

		if (!idx) {
			u16 t16;

			fixup = Add2Ptr(bh_data, fo);
			sample = *fixup;
			t16 = le16_to_cpu(sample);
			if (t16 >= 0x7FFF) {
				sample = *fixup = cpu_to_le16(1);
			} else {
				sample = cpu_to_le16(t16 + 1);
				*fixup = sample;
			}

			*(__le16 *)Add2Ptr(rhdr, fo) = sample;
		}

		ptr = Add2Ptr(bh_data, SECTOR_SIZE - sizeof(short));

		do {
			*++fixup = *ptr;
			*ptr = sample;
			ptr += SECTOR_SIZE / sizeof(short);
		} while (ptr < end_data);

		set_buffer_uptodate(bh);
		mark_buffer_dirty(bh);
		unlock_buffer(bh);

		if (sync) {
			int err2 = sync_dirty_buffer(bh);

			if (!err && err2)
				err = err2;
		}

		bytes -= op;
		rhdr = Add2Ptr(rhdr, op);
	}

	return err;
}

/*
 * ntfs_bio_pages - Read/write pages from/to disk.
 */
int ntfs_bio_pages(struct ntfs_sb_info *sbi, const struct runs_tree *run,
		   struct page **pages, u32 nr_pages, u64 vbo, u32 bytes,
		   enum req_op op)
{
	int err = 0;
	struct bio *new, *bio = NULL;
	struct super_block *sb = sbi->sb;
	struct block_device *bdev = sb->s_bdev;
	struct page *page;
	u8 cluster_bits = sbi->cluster_bits;
	CLST lcn, clen, vcn, vcn_next;
	u32 add, off, page_idx;
	u64 lbo, len;
	size_t run_idx;
	struct blk_plug plug;

	if (!bytes)
		return 0;

	blk_start_plug(&plug);

	/* Align vbo and bytes to be 512 bytes aligned. */
	lbo = (vbo + bytes + 511) & ~511ull;
	vbo = vbo & ~511ull;
	bytes = lbo - vbo;

	vcn = vbo >> cluster_bits;
	if (!run_lookup_entry(run, vcn, &lcn, &clen, &run_idx)) {
		err = -ENOENT;
		goto out;
	}
	off = vbo & sbi->cluster_mask;
	page_idx = 0;
	page = pages[0];

	for (;;) {
		lbo = ((u64)lcn << cluster_bits) + off;
		len = ((u64)clen << cluster_bits) - off;
new_bio:
		new = bio_alloc(bdev, nr_pages - page_idx, op, GFP_NOFS);
		if (bio) {
			bio_chain(bio, new);
			submit_bio(bio);
		}
		bio = new;
		bio->bi_iter.bi_sector = lbo >> 9;

		while (len) {
			off = vbo & (PAGE_SIZE - 1);
			add = off + len > PAGE_SIZE ? (PAGE_SIZE - off) : len;

			if (bio_add_page(bio, page, add, off) < add)
				goto new_bio;

			if (bytes <= add)
				goto out;
			bytes -= add;
			vbo += add;

			if (add + off == PAGE_SIZE) {
				page_idx += 1;
				if (WARN_ON(page_idx >= nr_pages)) {
					err = -EINVAL;
					goto out;
				}
				page = pages[page_idx];
			}

			if (len <= add)
				break;
			len -= add;
			lbo += add;
		}

		vcn_next = vcn + clen;
		if (!run_get_entry(run, ++run_idx, &vcn, &lcn, &clen) ||
		    vcn != vcn_next) {
			err = -ENOENT;
			goto out;
		}
		off = 0;
	}
out:
	if (bio) {
		if (!err)
			err = submit_bio_wait(bio);
		bio_put(bio);
	}
	blk_finish_plug(&plug);

	return err;
}

/*
 * ntfs_bio_fill_1 - Helper for ntfs_loadlog_and_replay().
 *
 * Fill on-disk logfile range by (-1)
 * this means empty logfile.
 */
int ntfs_bio_fill_1(struct ntfs_sb_info *sbi, const struct runs_tree *run)
{
	int err = 0;
	struct super_block *sb = sbi->sb;
	struct block_device *bdev = sb->s_bdev;
	u8 cluster_bits = sbi->cluster_bits;
	struct bio *new, *bio = NULL;
	CLST lcn, clen;
	u64 lbo, len;
	size_t run_idx;
	struct page *fill;
	void *kaddr;
	struct blk_plug plug;

	fill = alloc_page(GFP_KERNEL);
	if (!fill)
		return -ENOMEM;

	kaddr = kmap_atomic(fill);
	memset(kaddr, -1, PAGE_SIZE);
	kunmap_atomic(kaddr);
	flush_dcache_page(fill);
	lock_page(fill);

	if (!run_lookup_entry(run, 0, &lcn, &clen, &run_idx)) {
		err = -ENOENT;
		goto out;
	}

	/*
	 * TODO: Try blkdev_issue_write_same.
	 */
	blk_start_plug(&plug);
	do {
		lbo = (u64)lcn << cluster_bits;
		len = (u64)clen << cluster_bits;
new_bio:
		new = bio_alloc(bdev, BIO_MAX_VECS, REQ_OP_WRITE, GFP_NOFS);
		if (bio) {
			bio_chain(bio, new);
			submit_bio(bio);
		}
		bio = new;
		bio->bi_iter.bi_sector = lbo >> 9;

		for (;;) {
			u32 add = len > PAGE_SIZE ? PAGE_SIZE : len;

			if (bio_add_page(bio, fill, add, 0) < add)
				goto new_bio;

			lbo += add;
			if (len <= add)
				break;
			len -= add;
		}
	} while (run_get_entry(run, ++run_idx, NULL, &lcn, &clen));

	if (!err)
		err = submit_bio_wait(bio);
	bio_put(bio);

	blk_finish_plug(&plug);
out:
	unlock_page(fill);
	put_page(fill);

	return err;
}

int ntfs_vbo_to_lbo(struct ntfs_sb_info *sbi, const struct runs_tree *run,
		    u64 vbo, u64 *lbo, u64 *bytes)
{
	u32 off;
	CLST lcn, len;
	u8 cluster_bits = sbi->cluster_bits;

	if (!run_lookup_entry(run, vbo >> cluster_bits, &lcn, &len, NULL))
		return -ENOENT;

	off = vbo & sbi->cluster_mask;
	*lbo = lcn == SPARSE_LCN ? -1 : (((u64)lcn << cluster_bits) + off);
	*bytes = ((u64)len << cluster_bits) - off;

	return 0;
}

struct ntfs_inode *ntfs_new_inode(struct ntfs_sb_info *sbi, CLST rno,
				  enum RECORD_FLAG flag)
{
	int err = 0;
	struct super_block *sb = sbi->sb;
	struct inode *inode = new_inode(sb);
	struct ntfs_inode *ni;

	if (!inode)
		return ERR_PTR(-ENOMEM);

	ni = ntfs_i(inode);

	err = mi_format_new(&ni->mi, sbi, rno, flag, false);
	if (err)
		goto out;

	inode->i_ino = rno;
	if (insert_inode_locked(inode) < 0) {
		err = -EIO;
		goto out;
	}

out:
	if (err) {
		make_bad_inode(inode);
		iput(inode);
		ni = ERR_PTR(err);
	}
	return ni;
}

/*
 * O:BAG:BAD:(A;OICI;FA;;;WD)
 * Owner S-1-5-32-544 (Administrators)
 * Group S-1-5-32-544 (Administrators)
 * ACE: allow S-1-1-0 (Everyone) with FILE_ALL_ACCESS
 */
const u8 s_default_security[] __aligned(8) = {
	0x01, 0x00, 0x04, 0x80, 0x30, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00, 0x14, 0x00, 0x00, 0x00, 0x02, 0x00, 0x1C, 0x00,
	0x01, 0x00, 0x00, 0x00, 0x00, 0x03, 0x14, 0x00, 0xFF, 0x01, 0x1F, 0x00,
	0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
	0x01, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0x20, 0x00, 0x00, 0x00,
	0x20, 0x02, 0x00, 0x00, 0x01, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05,
	0x20, 0x00, 0x00, 0x00, 0x20, 0x02, 0x00, 0x00,
};

static_assert(sizeof(s_default_security) == 0x50);

static inline u32 sid_length(const struct SID *sid)
{
	return struct_size(sid, SubAuthority, sid->SubAuthorityCount);
}

/*
 * is_acl_valid
 *
 * Thanks Mark Harmstone for idea.
 */
static bool is_acl_valid(const struct ACL *acl, u32 len)
{
	const struct ACE_HEADER *ace;
	u32 i;
	u16 ace_count, ace_size;

	if (acl->AclRevision != ACL_REVISION &&
	    acl->AclRevision != ACL_REVISION_DS) {
		/*
		 * This value should be ACL_REVISION, unless the ACL contains an
		 * object-specific ACE, in which case this value must be ACL_REVISION_DS.
		 * All ACEs in an ACL must be at the same revision level.
		 */
		return false;
	}

	if (acl->Sbz1)
		return false;

	if (le16_to_cpu(acl->AclSize) > len)
		return false;

	if (acl->Sbz2)
		return false;

	len -= sizeof(struct ACL);
	ace = (struct ACE_HEADER *)&acl[1];
	ace_count = le16_to_cpu(acl->AceCount);

	for (i = 0; i < ace_count; i++) {
		if (len < sizeof(struct ACE_HEADER))
			return false;

		ace_size = le16_to_cpu(ace->AceSize);
		if (len < ace_size)
			return false;

		len -= ace_size;
		ace = Add2Ptr(ace, ace_size);
	}

	return true;
}

bool is_sd_valid(const struct SECURITY_DESCRIPTOR_RELATIVE *sd, u32 len)
{
	u32 sd_owner, sd_group, sd_sacl, sd_dacl;

	if (len < sizeof(struct SECURITY_DESCRIPTOR_RELATIVE))
		return false;

	if (sd->Revision != 1)
		return false;

	if (sd->Sbz1)
		return false;

	if (!(sd->Control & SE_SELF_RELATIVE))
		return false;

	sd_owner = le32_to_cpu(sd->Owner);
	if (sd_owner) {
		const struct SID *owner = Add2Ptr(sd, sd_owner);

		if (sd_owner + offsetof(struct SID, SubAuthority) > len)
			return false;

		if (owner->Revision != 1)
			return false;

		if (sd_owner + sid_length(owner) > len)
			return false;
	}

	sd_group = le32_to_cpu(sd->Group);
	if (sd_group) {
		const struct SID *group = Add2Ptr(sd, sd_group);

		if (sd_group + offsetof(struct SID, SubAuthority) > len)
			return false;

		if (group->Revision != 1)
			return false;

		if (sd_group + sid_length(group) > len)
			return false;
	}

	sd_sacl = le32_to_cpu(sd->Sacl);
	if (sd_sacl) {
		const struct ACL *sacl = Add2Ptr(sd, sd_sacl);

		if (sd_sacl + sizeof(struct ACL) > len)
			return false;

		if (!is_acl_valid(sacl, len - sd_sacl))
			return false;
	}

	sd_dacl = le32_to_cpu(sd->Dacl);
	if (sd_dacl) {
		const struct ACL *dacl = Add2Ptr(sd, sd_dacl);

		if (sd_dacl + sizeof(struct ACL) > len)
			return false;

		if (!is_acl_valid(dacl, len - sd_dacl))
			return false;
	}

	return true;
}

/*
 * ntfs_security_init - Load and parse $Secure.
 */
int ntfs_security_init(struct ntfs_sb_info *sbi)
{
	int err;
	struct super_block *sb = sbi->sb;
	struct inode *inode;
	struct ntfs_inode *ni;
	struct MFT_REF ref;
	struct ATTRIB *attr;
	struct ATTR_LIST_ENTRY *le;
	u64 sds_size;
	size_t off;
	struct NTFS_DE *ne;
	struct NTFS_DE_SII *sii_e;
	struct ntfs_fnd *fnd_sii = NULL;
	const struct INDEX_ROOT *root_sii;
	const struct INDEX_ROOT *root_sdh;
	struct ntfs_index *indx_sdh = &sbi->security.index_sdh;
	struct ntfs_index *indx_sii = &sbi->security.index_sii;

	ref.low = cpu_to_le32(MFT_REC_SECURE);
	ref.high = 0;
	ref.seq = cpu_to_le16(MFT_REC_SECURE);

	inode = ntfs_iget5(sb, &ref, &NAME_SECURE);
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		ntfs_err(sb, "Failed to load $Secure (%d).", err);
		inode = NULL;
		goto out;
	}

	ni = ntfs_i(inode);

	le = NULL;

	attr = ni_find_attr(ni, NULL, &le, ATTR_ROOT, SDH_NAME,
			    ARRAY_SIZE(SDH_NAME), NULL, NULL);
	if (!attr ||
	    !(root_sdh = resident_data_ex(attr, sizeof(struct INDEX_ROOT))) ||
	    root_sdh->type != ATTR_ZERO ||
	    root_sdh->rule != NTFS_COLLATION_TYPE_SECURITY_HASH ||
	    offsetof(struct INDEX_ROOT, ihdr) +
			    le32_to_cpu(root_sdh->ihdr.used) >
		    le32_to_cpu(attr->res.data_size)) {
		ntfs_err(sb, "$Secure::$SDH is corrupted.");
		err = -EINVAL;
		goto out;
	}

	err = indx_init(indx_sdh, sbi, attr, INDEX_MUTEX_SDH);
	if (err) {
		ntfs_err(sb, "Failed to initialize $Secure::$SDH (%d).", err);
		goto out;
	}

	attr = ni_find_attr(ni, attr, &le, ATTR_ROOT, SII_NAME,
			    ARRAY_SIZE(SII_NAME), NULL, NULL);
	if (!attr ||
	    !(root_sii = resident_data_ex(attr, sizeof(struct INDEX_ROOT))) ||
	    root_sii->type != ATTR_ZERO ||
	    root_sii->rule != NTFS_COLLATION_TYPE_UINT ||
	    offsetof(struct INDEX_ROOT, ihdr) +
			    le32_to_cpu(root_sii->ihdr.used) >
		    le32_to_cpu(attr->res.data_size)) {
		ntfs_err(sb, "$Secure::$SII is corrupted.");
		err = -EINVAL;
		goto out;
	}

	err = indx_init(indx_sii, sbi, attr, INDEX_MUTEX_SII);
	if (err) {
		ntfs_err(sb, "Failed to initialize $Secure::$SII (%d).", err);
		goto out;
	}

	fnd_sii = fnd_get();
	if (!fnd_sii) {
		err = -ENOMEM;
		goto out;
	}

	sds_size = inode->i_size;

	/* Find the last valid Id. */
	sbi->security.next_id = SECURITY_ID_FIRST;
	/* Always write new security at the end of bucket. */
	sbi->security.next_off =
		ALIGN(sds_size - SecurityDescriptorsBlockSize, 16);

	off = 0;
	ne = NULL;

	for (;;) {
		u32 next_id;

		err = indx_find_raw(indx_sii, ni, root_sii, &ne, &off, fnd_sii);
		if (err || !ne)
			break;

		sii_e = (struct NTFS_DE_SII *)ne;
		if (le16_to_cpu(ne->view.data_size) < sizeof(sii_e->sec_hdr))
			continue;

		next_id = le32_to_cpu(sii_e->sec_id) + 1;
		if (next_id >= sbi->security.next_id)
			sbi->security.next_id = next_id;
	}

	sbi->security.ni = ni;
	inode = NULL;
out:
	iput(inode);
	fnd_put(fnd_sii);

	return err;
}

/*
 * ntfs_get_security_by_id - Read security descriptor by id.
 */
int ntfs_get_security_by_id(struct ntfs_sb_info *sbi, __le32 security_id,
			    struct SECURITY_DESCRIPTOR_RELATIVE **sd,
			    size_t *size)
{
	int err;
	int diff;
	struct ntfs_inode *ni = sbi->security.ni;
	struct ntfs_index *indx = &sbi->security.index_sii;
	void *p = NULL;
	struct NTFS_DE_SII *sii_e;
	struct ntfs_fnd *fnd_sii;
	struct SECURITY_HDR d_security;
	const struct INDEX_ROOT *root_sii;
	u32 t32;

	*sd = NULL;

	mutex_lock_nested(&ni->ni_lock, NTFS_INODE_MUTEX_SECURITY);

	fnd_sii = fnd_get();
	if (!fnd_sii) {
		err = -ENOMEM;
		goto out;
	}

	root_sii = indx_get_root(indx, ni, NULL, NULL);
	if (!root_sii) {
		err = -EINVAL;
		goto out;
	}

	/* Try to find this SECURITY descriptor in SII indexes. */
	err = indx_find(indx, ni, root_sii, &security_id, sizeof(security_id),
			NULL, &diff, (struct NTFS_DE **)&sii_e, fnd_sii);
	if (err)
		goto out;

	if (diff)
		goto out;

	t32 = le32_to_cpu(sii_e->sec_hdr.size);
	if (t32 < sizeof(struct SECURITY_HDR)) {
		err = -EINVAL;
		goto out;
	}

	if (t32 > sizeof(struct SECURITY_HDR) + 0x10000) {
		/* Looks like too big security. 0x10000 - is arbitrary big number. */
		err = -EFBIG;
		goto out;
	}

	*size = t32 - sizeof(struct SECURITY_HDR);

	p = kmalloc(*size, GFP_NOFS);
	if (!p) {
		err = -ENOMEM;
		goto out;
	}

	err = ntfs_read_run_nb(sbi, &ni->file.run,
			       le64_to_cpu(sii_e->sec_hdr.off), &d_security,
			       sizeof(d_security), NULL);
	if (err)
		goto out;

	if (memcmp(&d_security, &sii_e->sec_hdr, sizeof(d_security))) {
		err = -EINVAL;
		goto out;
	}

	err = ntfs_read_run_nb(sbi, &ni->file.run,
			       le64_to_cpu(sii_e->sec_hdr.off) +
				       sizeof(struct SECURITY_HDR),
			       p, *size, NULL);
	if (err)
		goto out;

	*sd = p;
	p = NULL;

out:
	kfree(p);
	fnd_put(fnd_sii);
	ni_unlock(ni);

	return err;
}

/*
 * ntfs_insert_security - Insert security descriptor into $Secure::SDS.
 *
 * SECURITY Descriptor Stream data is organized into chunks of 256K bytes
 * and it contains a mirror copy of each security descriptor.  When writing
 * to a security descriptor at location X, another copy will be written at
 * location (X+256K).
 * When writing a security descriptor that will cross the 256K boundary,
 * the pointer will be advanced by 256K to skip
 * over the mirror portion.
 */
int ntfs_insert_security(struct ntfs_sb_info *sbi,
			 const struct SECURITY_DESCRIPTOR_RELATIVE *sd,
			 u32 size_sd, __le32 *security_id, bool *inserted)
{
	int err, diff;
	struct ntfs_inode *ni = sbi->security.ni;
	struct ntfs_index *indx_sdh = &sbi->security.index_sdh;
	struct ntfs_index *indx_sii = &sbi->security.index_sii;
	struct NTFS_DE_SDH *e;
	struct NTFS_DE_SDH sdh_e;
	struct NTFS_DE_SII sii_e;
	struct SECURITY_HDR *d_security;
	u32 new_sec_size = size_sd + sizeof(struct SECURITY_HDR);
	u32 aligned_sec_size = ALIGN(new_sec_size, 16);
	struct SECURITY_KEY hash_key;
	struct ntfs_fnd *fnd_sdh = NULL;
	const struct INDEX_ROOT *root_sdh;
	const struct INDEX_ROOT *root_sii;
	u64 mirr_off, new_sds_size;
	u32 next, left;

	static_assert((1 << Log2OfSecurityDescriptorsBlockSize) ==
		      SecurityDescriptorsBlockSize);

	hash_key.hash = security_hash(sd, size_sd);
	hash_key.sec_id = SECURITY_ID_INVALID;

	if (inserted)
		*inserted = false;
	*security_id = SECURITY_ID_INVALID;

	/* Allocate a temporal buffer. */
	d_security = kzalloc(aligned_sec_size, GFP_NOFS);
	if (!d_security)
		return -ENOMEM;

	mutex_lock_nested(&ni->ni_lock, NTFS_INODE_MUTEX_SECURITY);

	fnd_sdh = fnd_get();
	if (!fnd_sdh) {
		err = -ENOMEM;
		goto out;
	}

	root_sdh = indx_get_root(indx_sdh, ni, NULL, NULL);
	if (!root_sdh) {
		err = -EINVAL;
		goto out;
	}

	root_sii = indx_get_root(indx_sii, ni, NULL, NULL);
	if (!root_sii) {
		err = -EINVAL;
		goto out;
	}

	/*
	 * Check if such security already exists.
	 * Use "SDH" and hash -> to get the offset in "SDS".
	 */
	err = indx_find(indx_sdh, ni, root_sdh, &hash_key, sizeof(hash_key),
			&d_security->key.sec_id, &diff, (struct NTFS_DE **)&e,
			fnd_sdh);
	if (err)
		goto out;

	while (e) {
		if (le32_to_cpu(e->sec_hdr.size) == new_sec_size) {
			err = ntfs_read_run_nb(sbi, &ni->file.run,
					       le64_to_cpu(e->sec_hdr.off),
					       d_security, new_sec_size, NULL);
			if (err)
				goto out;

			if (le32_to_cpu(d_security->size) == new_sec_size &&
			    d_security->key.hash == hash_key.hash &&
			    !memcmp(d_security + 1, sd, size_sd)) {
				*security_id = d_security->key.sec_id;
				/* Such security already exists. */
				err = 0;
				goto out;
			}
		}

		err = indx_find_sort(indx_sdh, ni, root_sdh,
				     (struct NTFS_DE **)&e, fnd_sdh);
		if (err)
			goto out;

		if (!e || e->key.hash != hash_key.hash)
			break;
	}

	/* Zero unused space. */
	next = sbi->security.next_off & (SecurityDescriptorsBlockSize - 1);
	left = SecurityDescriptorsBlockSize - next;

	/* Zero gap until SecurityDescriptorsBlockSize. */
	if (left < new_sec_size) {
		/* Zero "left" bytes from sbi->security.next_off. */
		sbi->security.next_off += SecurityDescriptorsBlockSize + left;
	}

	/* Zero tail of previous security. */
	//used = ni->vfs_inode.i_size & (SecurityDescriptorsBlockSize - 1);

	/*
	 * Example:
	 * 0x40438 == ni->vfs_inode.i_size
	 * 0x00440 == sbi->security.next_off
	 * need to zero [0x438-0x440)
	 * if (next > used) {
	 *  u32 tozero = next - used;
	 *  zero "tozero" bytes from sbi->security.next_off - tozero
	 */

	/* Format new security descriptor. */
	d_security->key.hash = hash_key.hash;
	d_security->key.sec_id = cpu_to_le32(sbi->security.next_id);
	d_security->off = cpu_to_le64(sbi->security.next_off);
	d_security->size = cpu_to_le32(new_sec_size);
	memcpy(d_security + 1, sd, size_sd);

	/* Write main SDS bucket. */
	err = ntfs_sb_write_run(sbi, &ni->file.run, sbi->security.next_off,
				d_security, aligned_sec_size, 0);

	if (err)
		goto out;

	mirr_off = sbi->security.next_off + SecurityDescriptorsBlockSize;
	new_sds_size = mirr_off + aligned_sec_size;

	if (new_sds_size > ni->vfs_inode.i_size) {
		err = attr_set_size(ni, ATTR_DATA, SDS_NAME,
				    ARRAY_SIZE(SDS_NAME), &ni->file.run,
				    new_sds_size, &new_sds_size, false, NULL);
		if (err)
			goto out;
	}

	/* Write copy SDS bucket. */
	err = ntfs_sb_write_run(sbi, &ni->file.run, mirr_off, d_security,
				aligned_sec_size, 0);
	if (err)
		goto out;

	/* Fill SII entry. */
	sii_e.de.view.data_off =
		cpu_to_le16(offsetof(struct NTFS_DE_SII, sec_hdr));
	sii_e.de.view.data_size = cpu_to_le16(sizeof(struct SECURITY_HDR));
	sii_e.de.view.res = 0;
	sii_e.de.size = cpu_to_le16(sizeof(struct NTFS_DE_SII));
	sii_e.de.key_size = cpu_to_le16(sizeof(d_security->key.sec_id));
	sii_e.de.flags = 0;
	sii_e.de.res = 0;
	sii_e.sec_id = d_security->key.sec_id;
	memcpy(&sii_e.sec_hdr, d_security, sizeof(struct SECURITY_HDR));

	err = indx_insert_entry(indx_sii, ni, &sii_e.de, NULL, NULL, 0);
	if (err)
		goto out;

	/* Fill SDH entry. */
	sdh_e.de.view.data_off =
		cpu_to_le16(offsetof(struct NTFS_DE_SDH, sec_hdr));
	sdh_e.de.view.data_size = cpu_to_le16(sizeof(struct SECURITY_HDR));
	sdh_e.de.view.res = 0;
	sdh_e.de.size = cpu_to_le16(SIZEOF_SDH_DIRENTRY);
	sdh_e.de.key_size = cpu_to_le16(sizeof(sdh_e.key));
	sdh_e.de.flags = 0;
	sdh_e.de.res = 0;
	sdh_e.key.hash = d_security->key.hash;
	sdh_e.key.sec_id = d_security->key.sec_id;
	memcpy(&sdh_e.sec_hdr, d_security, sizeof(struct SECURITY_HDR));
	sdh_e.magic[0] = cpu_to_le16('I');
	sdh_e.magic[1] = cpu_to_le16('I');

	fnd_clear(fnd_sdh);
	err = indx_insert_entry(indx_sdh, ni, &sdh_e.de, (void *)(size_t)1,
				fnd_sdh, 0);
	if (err)
		goto out;

	*security_id = d_security->key.sec_id;
	if (inserted)
		*inserted = true;

	/* Update Id and offset for next descriptor. */
	sbi->security.next_id += 1;
	sbi->security.next_off += aligned_sec_size;

out:
	fnd_put(fnd_sdh);
	mark_inode_dirty(&ni->vfs_inode);
	ni_unlock(ni);
	kfree(d_security);

	return err;
}

/*
 * ntfs_reparse_init - Load and parse $Extend/$Reparse.
 */
int ntfs_reparse_init(struct ntfs_sb_info *sbi)
{
	int err;
	struct ntfs_inode *ni = sbi->reparse.ni;
	struct ntfs_index *indx = &sbi->reparse.index_r;
	struct ATTRIB *attr;
	struct ATTR_LIST_ENTRY *le;
	const struct INDEX_ROOT *root_r;

	if (!ni)
		return 0;

	le = NULL;
	attr = ni_find_attr(ni, NULL, &le, ATTR_ROOT, SR_NAME,
			    ARRAY_SIZE(SR_NAME), NULL, NULL);
	if (!attr) {
		err = -EINVAL;
		goto out;
	}

	root_r = resident_data(attr);
	if (root_r->type != ATTR_ZERO ||
	    root_r->rule != NTFS_COLLATION_TYPE_UINTS) {
		err = -EINVAL;
		goto out;
	}

	err = indx_init(indx, sbi, attr, INDEX_MUTEX_SR);
	if (err)
		goto out;

out:
	return err;
}

/*
 * ntfs_objid_init - Load and parse $Extend/$ObjId.
 */
int ntfs_objid_init(struct ntfs_sb_info *sbi)
{
	int err;
	struct ntfs_inode *ni = sbi->objid.ni;
	struct ntfs_index *indx = &sbi->objid.index_o;
	struct ATTRIB *attr;
	struct ATTR_LIST_ENTRY *le;
	const struct INDEX_ROOT *root;

	if (!ni)
		return 0;

	le = NULL;
	attr = ni_find_attr(ni, NULL, &le, ATTR_ROOT, SO_NAME,
			    ARRAY_SIZE(SO_NAME), NULL, NULL);
	if (!attr) {
		err = -EINVAL;
		goto out;
	}

	root = resident_data(attr);
	if (root->type != ATTR_ZERO ||
	    root->rule != NTFS_COLLATION_TYPE_UINTS) {
		err = -EINVAL;
		goto out;
	}

	err = indx_init(indx, sbi, attr, INDEX_MUTEX_SO);
	if (err)
		goto out;

out:
	return err;
}

int ntfs_objid_remove(struct ntfs_sb_info *sbi, struct GUID *guid)
{
	int err;
	struct ntfs_inode *ni = sbi->objid.ni;
	struct ntfs_index *indx = &sbi->objid.index_o;

	if (!ni)
		return -EINVAL;

	mutex_lock_nested(&ni->ni_lock, NTFS_INODE_MUTEX_OBJID);

	err = indx_delete_entry(indx, ni, guid, sizeof(*guid), NULL);

	mark_inode_dirty(&ni->vfs_inode);
	ni_unlock(ni);

	return err;
}

int ntfs_insert_reparse(struct ntfs_sb_info *sbi, __le32 rtag,
			const struct MFT_REF *ref)
{
	int err;
	struct ntfs_inode *ni = sbi->reparse.ni;
	struct ntfs_index *indx = &sbi->reparse.index_r;
	struct NTFS_DE_R re;

	if (!ni)
		return -EINVAL;

	memset(&re, 0, sizeof(re));

	re.de.view.data_off = cpu_to_le16(offsetof(struct NTFS_DE_R, zero));
	re.de.size = cpu_to_le16(sizeof(struct NTFS_DE_R));
	re.de.key_size = cpu_to_le16(sizeof(re.key));

	re.key.ReparseTag = rtag;
	memcpy(&re.key.ref, ref, sizeof(*ref));

	mutex_lock_nested(&ni->ni_lock, NTFS_INODE_MUTEX_REPARSE);

	err = indx_insert_entry(indx, ni, &re.de, NULL, NULL, 0);

	mark_inode_dirty(&ni->vfs_inode);
	ni_unlock(ni);

	return err;
}

int ntfs_remove_reparse(struct ntfs_sb_info *sbi, __le32 rtag,
			const struct MFT_REF *ref)
{
	int err, diff;
	struct ntfs_inode *ni = sbi->reparse.ni;
	struct ntfs_index *indx = &sbi->reparse.index_r;
	struct ntfs_fnd *fnd = NULL;
	struct REPARSE_KEY rkey;
	struct NTFS_DE_R *re;
	struct INDEX_ROOT *root_r;

	if (!ni)
		return -EINVAL;

	rkey.ReparseTag = rtag;
	rkey.ref = *ref;

	mutex_lock_nested(&ni->ni_lock, NTFS_INODE_MUTEX_REPARSE);

	if (rtag) {
		err = indx_delete_entry(indx, ni, &rkey, sizeof(rkey), NULL);
		goto out1;
	}

	fnd = fnd_get();
	if (!fnd) {
		err = -ENOMEM;
		goto out1;
	}

	root_r = indx_get_root(indx, ni, NULL, NULL);
	if (!root_r) {
		err = -EINVAL;
		goto out;
	}

	/* 1 - forces to ignore rkey.ReparseTag when comparing keys. */
	err = indx_find(indx, ni, root_r, &rkey, sizeof(rkey), (void *)1, &diff,
			(struct NTFS_DE **)&re, fnd);
	if (err)
		goto out;

	if (memcmp(&re->key.ref, ref, sizeof(*ref))) {
		/* Impossible. Looks like volume corrupt? */
		goto out;
	}

	memcpy(&rkey, &re->key, sizeof(rkey));

	fnd_put(fnd);
	fnd = NULL;

	err = indx_delete_entry(indx, ni, &rkey, sizeof(rkey), NULL);
	if (err)
		goto out;

out:
	fnd_put(fnd);

out1:
	mark_inode_dirty(&ni->vfs_inode);
	ni_unlock(ni);

	return err;
}

static inline void ntfs_unmap_and_discard(struct ntfs_sb_info *sbi, CLST lcn,
					  CLST len)
{
	ntfs_unmap_meta(sbi->sb, lcn, len);
	ntfs_discard(sbi, lcn, len);
}

void mark_as_free_ex(struct ntfs_sb_info *sbi, CLST lcn, CLST len, bool trim)
{
	CLST end, i, zone_len, zlen;
	struct wnd_bitmap *wnd = &sbi->used.bitmap;
	bool dirty = false;

	down_write_nested(&wnd->rw_lock, BITMAP_MUTEX_CLUSTERS);
	if (!wnd_is_used(wnd, lcn, len)) {
		/* mark volume as dirty out of wnd->rw_lock */
		dirty = true;

		end = lcn + len;
		len = 0;
		for (i = lcn; i < end; i++) {
			if (wnd_is_used(wnd, i, 1)) {
				if (!len)
					lcn = i;
				len += 1;
				continue;
			}

			if (!len)
				continue;

			if (trim)
				ntfs_unmap_and_discard(sbi, lcn, len);

			wnd_set_free(wnd, lcn, len);
			len = 0;
		}

		if (!len)
			goto out;
	}

	if (trim)
		ntfs_unmap_and_discard(sbi, lcn, len);
	wnd_set_free(wnd, lcn, len);

	/* append to MFT zone, if possible. */
	zone_len = wnd_zone_len(wnd);
	zlen = min(zone_len + len, sbi->zone_max);

	if (zlen == zone_len) {
		/* MFT zone already has maximum size. */
	} else if (!zone_len) {
		/* Create MFT zone only if 'zlen' is large enough. */
		if (zlen == sbi->zone_max)
			wnd_zone_set(wnd, lcn, zlen);
	} else {
		CLST zone_lcn = wnd_zone_bit(wnd);

		if (lcn + len == zone_lcn) {
			/* Append into head MFT zone. */
			wnd_zone_set(wnd, lcn, zlen);
		} else if (zone_lcn + zone_len == lcn) {
			/* Append into tail MFT zone. */
			wnd_zone_set(wnd, zone_lcn, zlen);
		}
	}

out:
	up_write(&wnd->rw_lock);
	if (dirty)
		ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
}

/*
 * run_deallocate - Deallocate clusters.
 */
int run_deallocate(struct ntfs_sb_info *sbi, const struct runs_tree *run,
		   bool trim)
{
	CLST lcn, len;
	size_t idx = 0;

	while (run_get_entry(run, idx++, NULL, &lcn, &len)) {
		if (lcn == SPARSE_LCN)
			continue;

		mark_as_free_ex(sbi, lcn, len, trim);
	}

	return 0;
}

static inline bool name_has_forbidden_chars(const struct le_str *fname)
{
	int i, ch;

	/* check for forbidden chars */
	for (i = 0; i < fname->len; ++i) {
		ch = le16_to_cpu(fname->name[i]);

		/* control chars */
		if (ch < 0x20)
			return true;

		switch (ch) {
		/* disallowed by Windows */
		case '\\':
		case '/':
		case ':':
		case '*':
		case '?':
		case '<':
		case '>':
		case '|':
		case '\"':
			return true;

		default:
			/* allowed char */
			break;
		}
	}

	/* file names cannot end with space or . */
	if (fname->len > 0) {
		ch = le16_to_cpu(fname->name[fname->len - 1]);
		if (ch == ' ' || ch == '.')
			return true;
	}

	return false;
}

static inline bool is_reserved_name(const struct ntfs_sb_info *sbi,
				    const struct le_str *fname)
{
	int port_digit;
	const __le16 *name = fname->name;
	int len = fname->len;
	const u16 *upcase = sbi->upcase;

	/* check for 3 chars reserved names (device names) */
	/* name by itself or with any extension is forbidden */
	if (len == 3 || (len > 3 && le16_to_cpu(name[3]) == '.'))
		if (!ntfs_cmp_names(name, 3, CON_NAME, 3, upcase, false) ||
		    !ntfs_cmp_names(name, 3, NUL_NAME, 3, upcase, false) ||
		    !ntfs_cmp_names(name, 3, AUX_NAME, 3, upcase, false) ||
		    !ntfs_cmp_names(name, 3, PRN_NAME, 3, upcase, false))
			return true;

	/* check for 4 chars reserved names (port name followed by 1..9) */
	/* name by itself or with any extension is forbidden */
	if (len == 4 || (len > 4 && le16_to_cpu(name[4]) == '.')) {
		port_digit = le16_to_cpu(name[3]);
		if (port_digit >= '1' && port_digit <= '9')
			if (!ntfs_cmp_names(name, 3, COM_NAME, 3, upcase,
					    false) ||
			    !ntfs_cmp_names(name, 3, LPT_NAME, 3, upcase,
					    false))
				return true;
	}

	return false;
}

/*
 * valid_windows_name - Check if a file name is valid in Windows.
 */
bool valid_windows_name(struct ntfs_sb_info *sbi, const struct le_str *fname)
{
	return !name_has_forbidden_chars(fname) &&
	       !is_reserved_name(sbi, fname);
}

/*
 * ntfs_set_label - updates current ntfs label.
 */
int ntfs_set_label(struct ntfs_sb_info *sbi, u8 *label, int len)
{
	int err;
	struct ATTRIB *attr;
	struct ntfs_inode *ni = sbi->volume.ni;
	const u8 max_ulen = 0x80; /* TODO: use attrdef to get maximum length */
	/* Allocate PATH_MAX bytes. */
	struct cpu_str *uni = __getname();

	if (!uni)
		return -ENOMEM;

	err = ntfs_nls_to_utf16(sbi, label, len, uni, (PATH_MAX - 2) / 2,
				UTF16_LITTLE_ENDIAN);
	if (err < 0)
		goto out;

	if (uni->len > max_ulen) {
		ntfs_warn(sbi->sb, "new label is too long");
		err = -EFBIG;
		goto out;
	}

	ni_lock(ni);

	/* Ignore any errors. */
	ni_remove_attr(ni, ATTR_LABEL, NULL, 0, false, NULL);

	err = ni_insert_resident(ni, uni->len * sizeof(u16), ATTR_LABEL, NULL,
				 0, &attr, NULL, NULL);
	if (err < 0)
		goto unlock_out;

	/* write new label in on-disk struct. */
	memcpy(resident_data(attr), uni->name, uni->len * sizeof(u16));

	/* update cached value of current label. */
	if (len >= ARRAY_SIZE(sbi->volume.label))
		len = ARRAY_SIZE(sbi->volume.label) - 1;
	memcpy(sbi->volume.label, label, len);
	sbi->volume.label[len] = 0;
	mark_inode_dirty_sync(&ni->vfs_inode);

unlock_out:
	ni_unlock(ni);

	if (!err)
		err = _ni_write_inode(&ni->vfs_inode, 0);

out:
	__putname(uni);
	return err;
}