[linux-block.git] / fs / ntfs3 / record.c

// SPDX-License-Identifier: GPL-2.0
/*
 *
 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
 *
 */

#include <linux/fs.h>

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

static inline int compare_attr(const struct ATTRIB *left, enum ATTR_TYPE type,
			       const __le16 *name, u8 name_len,
			       const u16 *upcase)
{
	/* First, compare the type codes. */
	int diff = le32_to_cpu(left->type) - le32_to_cpu(type);

	if (diff)
		return diff;

	/* They have the same type code, so we have to compare the names. */
	return ntfs_cmp_names(attr_name(left), left->name_len, name, name_len,
			      upcase, true);
}

/*
 * mi_new_attt_id
 *
 * Return: Unused attribute id that is less than mrec->next_attr_id.
 */
static __le16 mi_new_attt_id(struct mft_inode *mi)
{
	u16 free_id, max_id, t16;
	struct MFT_REC *rec = mi->mrec;
	struct ATTRIB *attr;
	__le16 id;

	id = rec->next_attr_id;
	free_id = le16_to_cpu(id);
	if (free_id < 0x7FFF) {
		rec->next_attr_id = cpu_to_le16(free_id + 1);
		return id;
	}

	/* One record can store up to 1024/24 ~= 42 attributes. */
	free_id = 0;
	max_id = 0;

	attr = NULL;

	for (;;) {
		attr = mi_enum_attr(mi, attr);
		if (!attr) {
			rec->next_attr_id = cpu_to_le16(max_id + 1);
			mi->dirty = true;
			return cpu_to_le16(free_id);
		}

		t16 = le16_to_cpu(attr->id);
		if (t16 == free_id) {
			free_id += 1;
			attr = NULL;
		} else if (max_id < t16)
			max_id = t16;
	}
}

int mi_get(struct ntfs_sb_info *sbi, CLST rno, struct mft_inode **mi)
{
	int err;
	struct mft_inode *m = kzalloc(sizeof(struct mft_inode), GFP_NOFS);

	if (!m)
		return -ENOMEM;

	err = mi_init(m, sbi, rno);
	if (err) {
		kfree(m);
		return err;
	}

	err = mi_read(m, false);
	if (err) {
		mi_put(m);
		return err;
	}

	*mi = m;
	return 0;
}

void mi_put(struct mft_inode *mi)
{
	mi_clear(mi);
	kfree(mi);
}

int mi_init(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno)
{
	mi->sbi = sbi;
	mi->rno = rno;
	mi->mrec = kmalloc(sbi->record_size, GFP_NOFS);
	if (!mi->mrec)
		return -ENOMEM;

	return 0;
}

/*
 * mi_read - Read MFT data.
 */
int mi_read(struct mft_inode *mi, bool is_mft)
{
	int err;
	struct MFT_REC *rec = mi->mrec;
	struct ntfs_sb_info *sbi = mi->sbi;
	u32 bpr = sbi->record_size;
	u64 vbo = (u64)mi->rno << sbi->record_bits;
	struct ntfs_inode *mft_ni = sbi->mft.ni;
	struct runs_tree *run = mft_ni ? &mft_ni->file.run : NULL;
	struct rw_semaphore *rw_lock = NULL;

	if (is_mounted(sbi)) {
		if (!is_mft) {
			rw_lock = &mft_ni->file.run_lock;
			down_read(rw_lock);
		}
	}

	err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
	if (rw_lock)
		up_read(rw_lock);
	if (!err)
		goto ok;

	if (err == -E_NTFS_FIXUP) {
		mi->dirty = true;
		goto ok;
	}

	if (err != -ENOENT)
		goto out;

	if (rw_lock) {
		ni_lock(mft_ni);
		down_write(rw_lock);
	}
	err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, &mft_ni->file.run,
				 vbo >> sbi->cluster_bits);
	if (rw_lock) {
		up_write(rw_lock);
		ni_unlock(mft_ni);
	}
	if (err)
		goto out;

	if (rw_lock)
		down_read(rw_lock);
	err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
	if (rw_lock)
		up_read(rw_lock);

	if (err == -E_NTFS_FIXUP) {
		mi->dirty = true;
		goto ok;
	}
	if (err)
		goto out;

ok:
	/* Check field 'total' only here. */
	if (le32_to_cpu(rec->total) != bpr) {
		err = -EINVAL;
		goto out;
	}

	return 0;

out:
	return err;
}

struct ATTRIB *mi_enum_attr(struct mft_inode *mi, struct ATTRIB *attr)
{
	const struct MFT_REC *rec = mi->mrec;
	u32 used = le32_to_cpu(rec->used);
	u32 t32, off, asize;
	u16 t16;

	if (!attr) {
		u32 total = le32_to_cpu(rec->total);

		off = le16_to_cpu(rec->attr_off);

		if (used > total)
			return NULL;

		if (off >= used || off < MFTRECORD_FIXUP_OFFSET_1 ||
		    !IS_ALIGNED(off, 4)) {
			return NULL;
		}

		/* Skip non-resident records. */
		if (!is_rec_inuse(rec))
			return NULL;

		attr = Add2Ptr(rec, off);
	} else {
		/* Check if input attr inside record. */
		off = PtrOffset(rec, attr);
		if (off >= used)
			return NULL;

		asize = le32_to_cpu(attr->size);
		if (asize < SIZEOF_RESIDENT) {
			/* Impossible 'cause we should not return such attribute. */
			return NULL;
		}

		if (off + asize < off) {
			/* Overflow check. */
			return NULL;
		}

		attr = Add2Ptr(attr, asize);
		off += asize;
	}

	asize = le32_to_cpu(attr->size);

	/* Can we use the first field (attr->type). */
	if (off + 8 > used) {
		static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
		return NULL;
	}

	if (attr->type == ATTR_END) {
		/* End of enumeration. */
		return NULL;
	}

	/* 0x100 is last known attribute for now. */
	t32 = le32_to_cpu(attr->type);
	if ((t32 & 0xf) || (t32 > 0x100))
		return NULL;

	/* Check overflow and boundary. */
	if (off + asize < off || off + asize > used)
		return NULL;

	/* Check size of attribute. */
	if (!attr->non_res) {
		if (asize < SIZEOF_RESIDENT)
			return NULL;

		t16 = le16_to_cpu(attr->res.data_off);

		if (t16 > asize)
			return NULL;

		t32 = le32_to_cpu(attr->res.data_size);
		if (t16 + t32 > asize)
			return NULL;

		t32 = sizeof(short) * attr->name_len;
		if (t32 && le16_to_cpu(attr->name_off) + t32 > t16)
			return NULL;

		return attr;
	}

	/* Check some nonresident fields. */
	if (attr->name_len &&
	    le16_to_cpu(attr->name_off) + sizeof(short) * attr->name_len >
		    le16_to_cpu(attr->nres.run_off)) {
		return NULL;
	}

	if (attr->nres.svcn || !is_attr_ext(attr)) {
		if (asize + 8 < SIZEOF_NONRESIDENT)
			return NULL;

		if (attr->nres.c_unit)
			return NULL;
	} else if (asize + 8 < SIZEOF_NONRESIDENT_EX)
		return NULL;

	return attr;
}

/*
 * mi_find_attr - Find the attribute by type and name and id.
 */
struct ATTRIB *mi_find_attr(struct mft_inode *mi, struct ATTRIB *attr,
			    enum ATTR_TYPE type, const __le16 *name,
			    size_t name_len, const __le16 *id)
{
	u32 type_in = le32_to_cpu(type);
	u32 atype;

next_attr:
	attr = mi_enum_attr(mi, attr);
	if (!attr)
		return NULL;

	atype = le32_to_cpu(attr->type);
	if (atype > type_in)
		return NULL;

	if (atype < type_in)
		goto next_attr;

	if (attr->name_len != name_len)
		goto next_attr;

	if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short)))
		goto next_attr;

	if (id && *id != attr->id)
		goto next_attr;

	return attr;
}

int mi_write(struct mft_inode *mi, int wait)
{
	struct MFT_REC *rec;
	int err;
	struct ntfs_sb_info *sbi;

	if (!mi->dirty)
		return 0;

	sbi = mi->sbi;
	rec = mi->mrec;

	err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait);
	if (err)
		return err;

	if (mi->rno < sbi->mft.recs_mirr)
		sbi->flags |= NTFS_FLAGS_MFTMIRR;

	mi->dirty = false;

	return 0;
}

int mi_format_new(struct mft_inode *mi, struct ntfs_sb_info *sbi, CLST rno,
		  __le16 flags, bool is_mft)
{
	int err;
	u16 seq = 1;
	struct MFT_REC *rec;
	u64 vbo = (u64)rno << sbi->record_bits;

	err = mi_init(mi, sbi, rno);
	if (err)
		return err;

	rec = mi->mrec;

	if (rno == MFT_REC_MFT) {
		;
	} else if (rno < MFT_REC_FREE) {
		seq = rno;
	} else if (rno >= sbi->mft.used) {
		;
	} else if (mi_read(mi, is_mft)) {
		;
	} else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) {
		/* Record is reused. Update its sequence number. */
		seq = le16_to_cpu(rec->seq) + 1;
		if (!seq)
			seq = 1;
	}

	memcpy(rec, sbi->new_rec, sbi->record_size);

	rec->seq = cpu_to_le16(seq);
	rec->flags = RECORD_FLAG_IN_USE | flags;

	mi->dirty = true;

	if (!mi->nb.nbufs) {
		struct ntfs_inode *ni = sbi->mft.ni;
		bool lock = false;

		if (is_mounted(sbi) && !is_mft) {
			down_read(&ni->file.run_lock);
			lock = true;
		}

		err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size,
				  &mi->nb);
		if (lock)
			up_read(&ni->file.run_lock);
	}

	return err;
}

/*
 * mi_insert_attr - Reserve space for new attribute.
 *
 * Return: Not full constructed attribute or NULL if not possible to create.
 */
struct ATTRIB *mi_insert_attr(struct mft_inode *mi, enum ATTR_TYPE type,
			      const __le16 *name, u8 name_len, u32 asize,
			      u16 name_off)
{
	size_t tail;
	struct ATTRIB *attr;
	__le16 id;
	struct MFT_REC *rec = mi->mrec;
	struct ntfs_sb_info *sbi = mi->sbi;
	u32 used = le32_to_cpu(rec->used);
	const u16 *upcase = sbi->upcase;

	/* Can we insert mi attribute? */
	if (used + asize > sbi->record_size)
		return NULL;

	/*
	 * Scan through the list of attributes to find the point
	 * at which we should insert it.
	 */
	attr = NULL;
	while ((attr = mi_enum_attr(mi, attr))) {
		int diff = compare_attr(attr, type, name, name_len, upcase);

		if (diff < 0)
			continue;

		if (!diff && !is_attr_indexed(attr))
			return NULL;
		break;
	}

	if (!attr) {
		/* Append. */
		tail = 8;
		attr = Add2Ptr(rec, used - 8);
	} else {
		/* Insert before 'attr'. */
		tail = used - PtrOffset(rec, attr);
	}

	id = mi_new_attt_id(mi);

	memmove(Add2Ptr(attr, asize), attr, tail);
	memset(attr, 0, asize);

	attr->type = type;
	attr->size = cpu_to_le32(asize);
	attr->name_len = name_len;
	attr->name_off = cpu_to_le16(name_off);
	attr->id = id;

	memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short));
	rec->used = cpu_to_le32(used + asize);

	mi->dirty = true;

	return attr;
}

/*
 * mi_remove_attr - Remove the attribute from record.
 *
 * NOTE: The source attr will point to next attribute.
 */
bool mi_remove_attr(struct ntfs_inode *ni, struct mft_inode *mi,
		    struct ATTRIB *attr)
{
	struct MFT_REC *rec = mi->mrec;
	u32 aoff = PtrOffset(rec, attr);
	u32 used = le32_to_cpu(rec->used);
	u32 asize = le32_to_cpu(attr->size);

	if (aoff + asize > used)
		return false;

	if (ni && is_attr_indexed(attr)) {
		le16_add_cpu(&ni->mi.mrec->hard_links, -1);
		ni->mi.dirty = true;
	}

	used -= asize;
	memmove(attr, Add2Ptr(attr, asize), used - aoff);
	rec->used = cpu_to_le32(used);
	mi->dirty = true;

	return true;
}

/* bytes = "new attribute size" - "old attribute size" */
bool mi_resize_attr(struct mft_inode *mi, struct ATTRIB *attr, int bytes)
{
	struct MFT_REC *rec = mi->mrec;
	u32 aoff = PtrOffset(rec, attr);
	u32 total, used = le32_to_cpu(rec->used);
	u32 nsize, asize = le32_to_cpu(attr->size);
	u32 rsize = le32_to_cpu(attr->res.data_size);
	int tail = (int)(used - aoff - asize);
	int dsize;
	char *next;

	if (tail < 0 || aoff >= used)
		return false;

	if (!bytes)
		return true;

	total = le32_to_cpu(rec->total);
	next = Add2Ptr(attr, asize);

	if (bytes > 0) {
		dsize = ALIGN(bytes, 8);
		if (used + dsize > total)
			return false;
		nsize = asize + dsize;
		/* Move tail */
		memmove(next + dsize, next, tail);
		memset(next, 0, dsize);
		used += dsize;
		rsize += dsize;
	} else {
		dsize = ALIGN(-bytes, 8);
		if (dsize > asize)
			return false;
		nsize = asize - dsize;
		memmove(next - dsize, next, tail);
		used -= dsize;
		rsize -= dsize;
	}

	rec->used = cpu_to_le32(used);
	attr->size = cpu_to_le32(nsize);
	if (!attr->non_res)
		attr->res.data_size = cpu_to_le32(rsize);
	mi->dirty = true;

	return true;
}

/*
 * Pack runs in MFT record.
 * If failed record is not changed.
 */
int mi_pack_runs(struct mft_inode *mi, struct ATTRIB *attr,
		 struct runs_tree *run, CLST len)
{
	int err = 0;
	struct ntfs_sb_info *sbi = mi->sbi;
	u32 new_run_size;
	CLST plen;
	struct MFT_REC *rec = mi->mrec;
	CLST svcn = le64_to_cpu(attr->nres.svcn);
	u32 used = le32_to_cpu(rec->used);
	u32 aoff = PtrOffset(rec, attr);
	u32 asize = le32_to_cpu(attr->size);
	char *next = Add2Ptr(attr, asize);
	u16 run_off = le16_to_cpu(attr->nres.run_off);
	u32 run_size = asize - run_off;
	u32 tail = used - aoff - asize;
	u32 dsize = sbi->record_size - used;

	/* Make a maximum gap in current record. */
	memmove(next + dsize, next, tail);

	/* Pack as much as possible. */
	err = run_pack(run, svcn, len, Add2Ptr(attr, run_off), run_size + dsize,
		       &plen);
	if (err < 0) {
		memmove(next, next + dsize, tail);
		return err;
	}

	new_run_size = ALIGN(err, 8);

	memmove(next + new_run_size - run_size, next + dsize, tail);

	attr->size = cpu_to_le32(asize + new_run_size - run_size);
	attr->nres.evcn = cpu_to_le64(svcn + plen - 1);
	rec->used = cpu_to_le32(used + new_run_size - run_size);
	mi->dirty = true;

	return 0;
}
Commit	Line	Data
4342306f KK	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	*
	4	* Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
	5	*
	6	*/
	7
4342306f	8	#include <linux/fs.h>
4342306f KK	9
	10	#include "debug.h"
	11	#include "ntfs.h"
	12	#include "ntfs_fs.h"
	13
	14	static inline int compare_attr(const struct ATTRIB *left, enum ATTR_TYPE type,
	15	const __le16 *name, u8 name_len,
	16	const u16 *upcase)
	17	{
e8b8e97f	18	/* First, compare the type codes. */
4342306f KK	19	int diff = le32_to_cpu(left->type) - le32_to_cpu(type);
	20
	21	if (diff)
	22	return diff;
	23
e8b8e97f	24	/* They have the same type code, so we have to compare the names. */
4342306f KK	25	return ntfs_cmp_names(attr_name(left), left->name_len, name, name_len,
	26	upcase, true);
	27	}
	28
	29	/*
	30	* mi_new_attt_id
	31	*
e8b8e97f	32	* Return: Unused attribute id that is less than mrec->next_attr_id.
4342306f KK	33	*/
	34	static __le16 mi_new_attt_id(struct mft_inode *mi)
	35	{
	36	u16 free_id, max_id, t16;
	37	struct MFT_REC *rec = mi->mrec;
	38	struct ATTRIB *attr;
	39	__le16 id;
	40
	41	id = rec->next_attr_id;
	42	free_id = le16_to_cpu(id);
	43	if (free_id < 0x7FFF) {
	44	rec->next_attr_id = cpu_to_le16(free_id + 1);
	45	return id;
	46	}
	47
e8b8e97f	48	/* One record can store up to 1024/24 ~= 42 attributes. */
4342306f KK	49	free_id = 0;
	50	max_id = 0;
	51
	52	attr = NULL;
	53
	54	for (;;) {
	55	attr = mi_enum_attr(mi, attr);
	56	if (!attr) {
	57	rec->next_attr_id = cpu_to_le16(max_id + 1);
	58	mi->dirty = true;
	59	return cpu_to_le16(free_id);
	60	}
	61
	62	t16 = le16_to_cpu(attr->id);
	63	if (t16 == free_id) {
	64	free_id += 1;
	65	attr = NULL;
	66	} else if (max_id < t16)
	67	max_id = t16;
	68	}
	69	}
	70
	71	int mi_get(struct ntfs_sb_info sbi, CLST rno, struct mft_inode *mi)
	72	{
	73	int err;
195c52bd	74	struct mft_inode *m = kzalloc(sizeof(struct mft_inode), GFP_NOFS);
4342306f KK	75
	76	if (!m)
	77	return -ENOMEM;
	78
	79	err = mi_init(m, sbi, rno);
	80	if (err) {
195c52bd	81	kfree(m);
4342306f KK	82	return err;
	83	}
	84
	85	err = mi_read(m, false);
	86	if (err) {
	87	mi_put(m);
	88	return err;
	89	}
	90
	91	*mi = m;
	92	return 0;
	93	}
	94
	95	void mi_put(struct mft_inode *mi)
	96	{
	97	mi_clear(mi);
195c52bd	98	kfree(mi);
4342306f KK	99	}
	100
	101	int mi_init(struct mft_inode mi, struct ntfs_sb_info sbi, CLST rno)
	102	{
	103	mi->sbi = sbi;
	104	mi->rno = rno;
195c52bd	105	mi->mrec = kmalloc(sbi->record_size, GFP_NOFS);
4342306f KK	106	if (!mi->mrec)
	107	return -ENOMEM;
	108
	109	return 0;
	110	}
	111
	112	/*
e8b8e97f	113	* mi_read - Read MFT data.
4342306f KK	114	*/
	115	int mi_read(struct mft_inode *mi, bool is_mft)
	116	{
	117	int err;
	118	struct MFT_REC *rec = mi->mrec;
	119	struct ntfs_sb_info *sbi = mi->sbi;
	120	u32 bpr = sbi->record_size;
	121	u64 vbo = (u64)mi->rno << sbi->record_bits;
	122	struct ntfs_inode *mft_ni = sbi->mft.ni;
	123	struct runs_tree *run = mft_ni ? &mft_ni->file.run : NULL;
	124	struct rw_semaphore *rw_lock = NULL;
	125
	126	if (is_mounted(sbi)) {
	127	if (!is_mft) {
	128	rw_lock = &mft_ni->file.run_lock;
	129	down_read(rw_lock);
	130	}
	131	}
	132
	133	err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
	134	if (rw_lock)
	135	up_read(rw_lock);
	136	if (!err)
	137	goto ok;
	138
	139	if (err == -E_NTFS_FIXUP) {
	140	mi->dirty = true;
	141	goto ok;
	142	}
	143
	144	if (err != -ENOENT)
	145	goto out;
	146
	147	if (rw_lock) {
	148	ni_lock(mft_ni);
	149	down_write(rw_lock);
	150	}
	151	err = attr_load_runs_vcn(mft_ni, ATTR_DATA, NULL, 0, &mft_ni->file.run,
	152	vbo >> sbi->cluster_bits);
	153	if (rw_lock) {
	154	up_write(rw_lock);
	155	ni_unlock(mft_ni);
	156	}
	157	if (err)
	158	goto out;
	159
	160	if (rw_lock)
	161	down_read(rw_lock);
	162	err = ntfs_read_bh(sbi, run, vbo, &rec->rhdr, bpr, &mi->nb);
	163	if (rw_lock)
	164	up_read(rw_lock);
	165
	166	if (err == -E_NTFS_FIXUP) {
	167	mi->dirty = true;
	168	goto ok;
	169	}
	170	if (err)
	171	goto out;
	172
	173	ok:
e8b8e97f	174	/* Check field 'total' only here. */
4342306f KK	175	if (le32_to_cpu(rec->total) != bpr) {
	176	err = -EINVAL;
	177	goto out;
	178	}
	179
	180	return 0;
	181
	182	out:
	183	return err;
	184	}
	185
	186	struct ATTRIB mi_enum_attr(struct mft_inode mi, struct ATTRIB *attr)
	187	{
	188	const struct MFT_REC *rec = mi->mrec;
	189	u32 used = le32_to_cpu(rec->used);
	190	u32 t32, off, asize;
	191	u16 t16;
	192
	193	if (!attr) {
	194	u32 total = le32_to_cpu(rec->total);
	195
	196	off = le16_to_cpu(rec->attr_off);
	197
	198	if (used > total)
	199	return NULL;
	200
	201	if (off >= used \|\| off < MFTRECORD_FIXUP_OFFSET_1 \|\|
fa3cacf5	202	!IS_ALIGNED(off, 4)) {
4342306f KK	203	return NULL;
	204	}
	205
e8b8e97f	206	/* Skip non-resident records. */
4342306f KK	207	if (!is_rec_inuse(rec))
	208	return NULL;
	209
	210	attr = Add2Ptr(rec, off);
	211	} else {
e8b8e97f	212	/* Check if input attr inside record. */
4342306f KK	213	off = PtrOffset(rec, attr);
	214	if (off >= used)
	215	return NULL;
	216
	217	asize = le32_to_cpu(attr->size);
	218	if (asize < SIZEOF_RESIDENT) {
d3624466	219	/* Impossible 'cause we should not return such attribute. */
4342306f KK	220	return NULL;
	221	}
	222
30200ef8 KK	223	if (off + asize < off) {
	224	/* Overflow check. */
	225	return NULL;
	226	}
	227
4342306f KK	228	attr = Add2Ptr(attr, asize);
	229	off += asize;
	230	}
	231
	232	asize = le32_to_cpu(attr->size);
	233
e8b8e97f	234	/* Can we use the first field (attr->type). */
4342306f	235	if (off + 8 > used) {
fa3cacf5	236	static_assert(ALIGN(sizeof(enum ATTR_TYPE), 8) == 8);
4342306f KK	237	return NULL;
	238	}
	239
	240	if (attr->type == ATTR_END) {
e8b8e97f	241	/* End of enumeration. */
4342306f KK	242	return NULL;
	243	}
	244
e8b8e97f	245	/* 0x100 is last known attribute for now. */
4342306f KK	246	t32 = le32_to_cpu(attr->type);
	247	if ((t32 & 0xf) \|\| (t32 > 0x100))
	248	return NULL;
	249
4f082a75 EL	250	/* Check overflow and boundary. */
4f082a75 EL	251	if (off + asize < off \|\| off + asize > used)
4342306f KK	252	return NULL;
4342306f KK	253
e8b8e97f	254	/* Check size of attribute. */
4342306f KK	255	if (!attr->non_res) {
	256	if (asize < SIZEOF_RESIDENT)
	257	return NULL;
	258
	259	t16 = le16_to_cpu(attr->res.data_off);
	260
	261	if (t16 > asize)
	262	return NULL;
	263
	264	t32 = le32_to_cpu(attr->res.data_size);
	265	if (t16 + t32 > asize)
	266	return NULL;
	267
36963cf2 KK	268	t32 = sizeof(short) * attr->name_len;
36963cf2 KK	269	if (t32 && le16_to_cpu(attr->name_off) + t32 > t16)
54e45702	270	return NULL;
54e45702	271
4342306f KK	272	return attr;
	273	}
	274
e8b8e97f	275	/* Check some nonresident fields. */
4342306f KK	276	if (attr->name_len &&
	277	le16_to_cpu(attr->name_off) + sizeof(short) * attr->name_len >
	278	le16_to_cpu(attr->nres.run_off)) {
	279	return NULL;
	280	}
	281
	282	if (attr->nres.svcn \|\| !is_attr_ext(attr)) {
	283	if (asize + 8 < SIZEOF_NONRESIDENT)
	284	return NULL;
	285
	286	if (attr->nres.c_unit)
	287	return NULL;
	288	} else if (asize + 8 < SIZEOF_NONRESIDENT_EX)
	289	return NULL;
	290
	291	return attr;
	292	}
	293
	294	/*
e8b8e97f	295	* mi_find_attr - Find the attribute by type and name and id.
4342306f KK	296	*/
	297	struct ATTRIB mi_find_attr(struct mft_inode mi, struct ATTRIB *attr,
	298	enum ATTR_TYPE type, const __le16 *name,
	299	size_t name_len, const __le16 *id)
	300	{
	301	u32 type_in = le32_to_cpu(type);
	302	u32 atype;
	303
	304	next_attr:
	305	attr = mi_enum_attr(mi, attr);
	306	if (!attr)
	307	return NULL;
	308
	309	atype = le32_to_cpu(attr->type);
	310	if (atype > type_in)
	311	return NULL;
	312
	313	if (atype < type_in)
	314	goto next_attr;
	315
	316	if (attr->name_len != name_len)
	317	goto next_attr;
	318
	319	if (name_len && memcmp(attr_name(attr), name, name_len * sizeof(short)))
	320	goto next_attr;
	321
	322	if (id && *id != attr->id)
	323	goto next_attr;
	324
	325	return attr;
	326	}
	327
	328	int mi_write(struct mft_inode *mi, int wait)
	329	{
	330	struct MFT_REC *rec;
	331	int err;
	332	struct ntfs_sb_info *sbi;
	333
	334	if (!mi->dirty)
	335	return 0;
	336
	337	sbi = mi->sbi;
	338	rec = mi->mrec;
	339
	340	err = ntfs_write_bh(sbi, &rec->rhdr, &mi->nb, wait);
	341	if (err)
	342	return err;
	343
	344	if (mi->rno < sbi->mft.recs_mirr)
	345	sbi->flags \|= NTFS_FLAGS_MFTMIRR;
	346
	347	mi->dirty = false;
	348
	349	return 0;
	350	}
	351
	352	int mi_format_new(struct mft_inode mi, struct ntfs_sb_info sbi, CLST rno,
	353	__le16 flags, bool is_mft)
	354	{
	355	int err;
	356	u16 seq = 1;
	357	struct MFT_REC *rec;
	358	u64 vbo = (u64)rno << sbi->record_bits;
	359
360	err = mi_init(mi, sbi, rno);
361	if (err)
362	return err;
363
364	rec = mi->mrec;
365
366	if (rno == MFT_REC_MFT) {
367	;
368	} else if (rno < MFT_REC_FREE) {
369	seq = rno;
370	} else if (rno >= sbi->mft.used) {
371	;
372	} else if (mi_read(mi, is_mft)) {
373	;
374	} else if (rec->rhdr.sign == NTFS_FILE_SIGNATURE) {
e8b8e97f	375	/* Record is reused. Update its sequence number. */
4342306f KK	376	seq = le16_to_cpu(rec->seq) + 1;
	377	if (!seq)
	378	seq = 1;
	379	}
	380
	381	memcpy(rec, sbi->new_rec, sbi->record_size);
	382
	383	rec->seq = cpu_to_le16(seq);
	384	rec->flags = RECORD_FLAG_IN_USE \| flags;
	385
	386	mi->dirty = true;
	387
	388	if (!mi->nb.nbufs) {
	389	struct ntfs_inode *ni = sbi->mft.ni;
	390	bool lock = false;
	391
	392	if (is_mounted(sbi) && !is_mft) {
	393	down_read(&ni->file.run_lock);
	394	lock = true;
	395	}
	396
	397	err = ntfs_get_bh(sbi, &ni->file.run, vbo, sbi->record_size,
	398	&mi->nb);
	399	if (lock)
	400	up_read(&ni->file.run_lock);
	401	}
	402
	403	return err;
	404	}
	405
4342306f	406	/*
e8b8e97f	407	* mi_insert_attr - Reserve space for new attribute.
4342306f	408	*
e8b8e97f	409	* Return: Not full constructed attribute or NULL if not possible to create.
4342306f KK	410	*/
	411	struct ATTRIB mi_insert_attr(struct mft_inode mi, enum ATTR_TYPE type,
	412	const __le16 *name, u8 name_len, u32 asize,
	413	u16 name_off)
	414	{
	415	size_t tail;
	416	struct ATTRIB *attr;
	417	__le16 id;
	418	struct MFT_REC *rec = mi->mrec;
	419	struct ntfs_sb_info *sbi = mi->sbi;
	420	u32 used = le32_to_cpu(rec->used);
	421	const u16 *upcase = sbi->upcase;
4342306f KK	422
4342306f KK	423	/* Can we insert mi attribute? */
96de65a9	424	if (used + asize > sbi->record_size)
4342306f KK	425	return NULL;
	426
	427	/*
	428	* Scan through the list of attributes to find the point
	429	* at which we should insert it.
	430	*/
	431	attr = NULL;
	432	while ((attr = mi_enum_attr(mi, attr))) {
96de65a9	433	int diff = compare_attr(attr, type, name, name_len, upcase);
19d1b787	434
4342306f KK	435	if (diff < 0)
	436	continue;
	437
19d1b787	438	if (!diff && !is_attr_indexed(attr))
4342306f KK	439	return NULL;
	440	break;
	441	}
	442
	443	if (!attr) {
96de65a9 KK	444	/* Append. */
96de65a9 KK	445	tail = 8;
4342306f KK	446	attr = Add2Ptr(rec, used - 8);
4342306f KK	447	} else {
96de65a9	448	/* Insert before 'attr'. */
4342306f KK	449	tail = used - PtrOffset(rec, attr);
	450	}
	451
	452	id = mi_new_attt_id(mi);
	453
	454	memmove(Add2Ptr(attr, asize), attr, tail);
	455	memset(attr, 0, asize);
	456
	457	attr->type = type;
	458	attr->size = cpu_to_le32(asize);
	459	attr->name_len = name_len;
	460	attr->name_off = cpu_to_le16(name_off);
	461	attr->id = id;
	462
	463	memmove(Add2Ptr(attr, name_off), name, name_len * sizeof(short));
	464	rec->used = cpu_to_le32(used + asize);
	465
	466	mi->dirty = true;
	467
	468	return attr;
	469	}
	470
	471	/*
e8b8e97f	472	* mi_remove_attr - Remove the attribute from record.
4342306f	473	*
e8b8e97f	474	* NOTE: The source attr will point to next attribute.
4342306f	475	*/
78ab59fe KK	476	bool mi_remove_attr(struct ntfs_inode ni, struct mft_inode mi,
78ab59fe KK	477	struct ATTRIB *attr)
4342306f KK	478	{
	479	struct MFT_REC *rec = mi->mrec;
	480	u32 aoff = PtrOffset(rec, attr);
	481	u32 used = le32_to_cpu(rec->used);
	482	u32 asize = le32_to_cpu(attr->size);
	483
	484	if (aoff + asize > used)
	485	return false;
	486
78ab59fe KK	487	if (ni && is_attr_indexed(attr)) {
	488	le16_add_cpu(&ni->mi.mrec->hard_links, -1);
	489	ni->mi.dirty = true;
	490	}
	491
4342306f KK	492	used -= asize;
	493	memmove(attr, Add2Ptr(attr, asize), used - aoff);
	494	rec->used = cpu_to_le32(used);
	495	mi->dirty = true;
	496
	497	return true;
	498	}
	499
	500	/* bytes = "new attribute size" - "old attribute size" */
	501	bool mi_resize_attr(struct mft_inode mi, struct ATTRIB attr, int bytes)
	502	{
	503	struct MFT_REC *rec = mi->mrec;
	504	u32 aoff = PtrOffset(rec, attr);
	505	u32 total, used = le32_to_cpu(rec->used);
	506	u32 nsize, asize = le32_to_cpu(attr->size);
	507	u32 rsize = le32_to_cpu(attr->res.data_size);
	508	int tail = (int)(used - aoff - asize);
	509	int dsize;
	510	char *next;
	511
	512	if (tail < 0 \|\| aoff >= used)
	513	return false;
	514
	515	if (!bytes)
	516	return true;
	517
	518	total = le32_to_cpu(rec->total);
	519	next = Add2Ptr(attr, asize);
	520
	521	if (bytes > 0) {
fa3cacf5	522	dsize = ALIGN(bytes, 8);
4342306f KK	523	if (used + dsize > total)
	524	return false;
	525	nsize = asize + dsize;
e8b8e97f	526	/* Move tail */
4342306f KK	527	memmove(next + dsize, next, tail);
	528	memset(next, 0, dsize);
	529	used += dsize;
	530	rsize += dsize;
	531	} else {
fa3cacf5	532	dsize = ALIGN(-bytes, 8);
4342306f KK	533	if (dsize > asize)
	534	return false;
	535	nsize = asize - dsize;
	536	memmove(next - dsize, next, tail);
	537	used -= dsize;
	538	rsize -= dsize;
	539	}
	540
	541	rec->used = cpu_to_le32(used);
	542	attr->size = cpu_to_le32(nsize);
	543	if (!attr->non_res)
	544	attr->res.data_size = cpu_to_le32(rsize);
	545	mi->dirty = true;
	546
	547	return true;
	548	}
	549
bd6ae049 KK	550	/*
	551	* Pack runs in MFT record.
	552	* If failed record is not changed.
	553	*/
4342306f KK	554	int mi_pack_runs(struct mft_inode mi, struct ATTRIB attr,
	555	struct runs_tree *run, CLST len)
	556	{
	557	int err = 0;
	558	struct ntfs_sb_info *sbi = mi->sbi;
	559	u32 new_run_size;
	560	CLST plen;
	561	struct MFT_REC *rec = mi->mrec;
	562	CLST svcn = le64_to_cpu(attr->nres.svcn);
	563	u32 used = le32_to_cpu(rec->used);
	564	u32 aoff = PtrOffset(rec, attr);
	565	u32 asize = le32_to_cpu(attr->size);
	566	char *next = Add2Ptr(attr, asize);
	567	u16 run_off = le16_to_cpu(attr->nres.run_off);
	568	u32 run_size = asize - run_off;
	569	u32 tail = used - aoff - asize;
	570	u32 dsize = sbi->record_size - used;
	571
e8b8e97f	572	/* Make a maximum gap in current record. */
4342306f KK	573	memmove(next + dsize, next, tail);
4342306f KK	574
e8b8e97f	575	/* Pack as much as possible. */
4342306f KK	576	err = run_pack(run, svcn, len, Add2Ptr(attr, run_off), run_size + dsize,
	577	&plen);
	578	if (err < 0) {
	579	memmove(next, next + dsize, tail);
	580	return err;
	581	}
	582
fa3cacf5	583	new_run_size = ALIGN(err, 8);
4342306f KK	584
	585	memmove(next + new_run_size - run_size, next + dsize, tail);
	586
	587	attr->size = cpu_to_le32(asize + new_run_size - run_size);
	588	attr->nres.evcn = cpu_to_le64(svcn + plen - 1);
	589	rec->used = cpu_to_le32(used + new_run_size - run_size);
	590	mi->dirty = true;
	591
	592	return 0;
	593	}