xref: /openbmc/linux/fs/ntfs3/index.c (revision 2984f26a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *
4  * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
5  *
6  */
7 
8 #include <linux/blkdev.h>
9 #include <linux/buffer_head.h>
10 #include <linux/fs.h>
11 #include <linux/kernel.h>
12 
13 #include "debug.h"
14 #include "ntfs.h"
15 #include "ntfs_fs.h"
16 
17 static const struct INDEX_NAMES {
18 	const __le16 *name;
19 	u8 name_len;
20 } s_index_names[INDEX_MUTEX_TOTAL] = {
21 	{ I30_NAME, ARRAY_SIZE(I30_NAME) }, { SII_NAME, ARRAY_SIZE(SII_NAME) },
22 	{ SDH_NAME, ARRAY_SIZE(SDH_NAME) }, { SO_NAME, ARRAY_SIZE(SO_NAME) },
23 	{ SQ_NAME, ARRAY_SIZE(SQ_NAME) },   { SR_NAME, ARRAY_SIZE(SR_NAME) },
24 };
25 
26 /*
27  * cmp_fnames - Compare two names in index.
28  *
29  * if l1 != 0
30  *   Both names are little endian on-disk ATTR_FILE_NAME structs.
31  * else
32  *   key1 - cpu_str, key2 - ATTR_FILE_NAME
33  */
34 static int cmp_fnames(const void *key1, size_t l1, const void *key2, size_t l2,
35 		      const void *data)
36 {
37 	const struct ATTR_FILE_NAME *f2 = key2;
38 	const struct ntfs_sb_info *sbi = data;
39 	const struct ATTR_FILE_NAME *f1;
40 	u16 fsize2;
41 	bool both_case;
42 
43 	if (l2 <= offsetof(struct ATTR_FILE_NAME, name))
44 		return -1;
45 
46 	fsize2 = fname_full_size(f2);
47 	if (l2 < fsize2)
48 		return -1;
49 
50 	both_case = f2->type != FILE_NAME_DOS && !sbi->options->nocase;
51 	if (!l1) {
52 		const struct le_str *s2 = (struct le_str *)&f2->name_len;
53 
54 		/*
55 		 * If names are equal (case insensitive)
56 		 * try to compare it case sensitive.
57 		 */
58 		return ntfs_cmp_names_cpu(key1, s2, sbi->upcase, both_case);
59 	}
60 
61 	f1 = key1;
62 	return ntfs_cmp_names(f1->name, f1->name_len, f2->name, f2->name_len,
63 			      sbi->upcase, both_case);
64 }
65 
66 /*
67  * cmp_uint - $SII of $Secure and $Q of Quota
68  */
69 static int cmp_uint(const void *key1, size_t l1, const void *key2, size_t l2,
70 		    const void *data)
71 {
72 	const u32 *k1 = key1;
73 	const u32 *k2 = key2;
74 
75 	if (l2 < sizeof(u32))
76 		return -1;
77 
78 	if (*k1 < *k2)
79 		return -1;
80 	if (*k1 > *k2)
81 		return 1;
82 	return 0;
83 }
84 
85 /*
86  * cmp_sdh - $SDH of $Secure
87  */
88 static int cmp_sdh(const void *key1, size_t l1, const void *key2, size_t l2,
89 		   const void *data)
90 {
91 	const struct SECURITY_KEY *k1 = key1;
92 	const struct SECURITY_KEY *k2 = key2;
93 	u32 t1, t2;
94 
95 	if (l2 < sizeof(struct SECURITY_KEY))
96 		return -1;
97 
98 	t1 = le32_to_cpu(k1->hash);
99 	t2 = le32_to_cpu(k2->hash);
100 
101 	/* First value is a hash value itself. */
102 	if (t1 < t2)
103 		return -1;
104 	if (t1 > t2)
105 		return 1;
106 
107 	/* Second value is security Id. */
108 	if (data) {
109 		t1 = le32_to_cpu(k1->sec_id);
110 		t2 = le32_to_cpu(k2->sec_id);
111 		if (t1 < t2)
112 			return -1;
113 		if (t1 > t2)
114 			return 1;
115 	}
116 
117 	return 0;
118 }
119 
120 /*
121  * cmp_uints - $O of ObjId and "$R" for Reparse.
122  */
123 static int cmp_uints(const void *key1, size_t l1, const void *key2, size_t l2,
124 		     const void *data)
125 {
126 	const __le32 *k1 = key1;
127 	const __le32 *k2 = key2;
128 	size_t count;
129 
130 	if ((size_t)data == 1) {
131 		/*
132 		 * ni_delete_all -> ntfs_remove_reparse ->
133 		 * delete all with this reference.
134 		 * k1, k2 - pointers to REPARSE_KEY
135 		 */
136 
137 		k1 += 1; // Skip REPARSE_KEY.ReparseTag
138 		k2 += 1; // Skip REPARSE_KEY.ReparseTag
139 		if (l2 <= sizeof(int))
140 			return -1;
141 		l2 -= sizeof(int);
142 		if (l1 <= sizeof(int))
143 			return 1;
144 		l1 -= sizeof(int);
145 	}
146 
147 	if (l2 < sizeof(int))
148 		return -1;
149 
150 	for (count = min(l1, l2) >> 2; count > 0; --count, ++k1, ++k2) {
151 		u32 t1 = le32_to_cpu(*k1);
152 		u32 t2 = le32_to_cpu(*k2);
153 
154 		if (t1 > t2)
155 			return 1;
156 		if (t1 < t2)
157 			return -1;
158 	}
159 
160 	if (l1 > l2)
161 		return 1;
162 	if (l1 < l2)
163 		return -1;
164 
165 	return 0;
166 }
167 
168 static inline NTFS_CMP_FUNC get_cmp_func(const struct INDEX_ROOT *root)
169 {
170 	switch (root->type) {
171 	case ATTR_NAME:
172 		if (root->rule == NTFS_COLLATION_TYPE_FILENAME)
173 			return &cmp_fnames;
174 		break;
175 	case ATTR_ZERO:
176 		switch (root->rule) {
177 		case NTFS_COLLATION_TYPE_UINT:
178 			return &cmp_uint;
179 		case NTFS_COLLATION_TYPE_SECURITY_HASH:
180 			return &cmp_sdh;
181 		case NTFS_COLLATION_TYPE_UINTS:
182 			return &cmp_uints;
183 		default:
184 			break;
185 		}
186 		break;
187 	default:
188 		break;
189 	}
190 
191 	return NULL;
192 }
193 
194 struct bmp_buf {
195 	struct ATTRIB *b;
196 	struct mft_inode *mi;
197 	struct buffer_head *bh;
198 	ulong *buf;
199 	size_t bit;
200 	u32 nbits;
201 	u64 new_valid;
202 };
203 
204 static int bmp_buf_get(struct ntfs_index *indx, struct ntfs_inode *ni,
205 		       size_t bit, struct bmp_buf *bbuf)
206 {
207 	struct ATTRIB *b;
208 	size_t data_size, valid_size, vbo, off = bit >> 3;
209 	struct ntfs_sb_info *sbi = ni->mi.sbi;
210 	CLST vcn = off >> sbi->cluster_bits;
211 	struct ATTR_LIST_ENTRY *le = NULL;
212 	struct buffer_head *bh;
213 	struct super_block *sb;
214 	u32 blocksize;
215 	const struct INDEX_NAMES *in = &s_index_names[indx->type];
216 
217 	bbuf->bh = NULL;
218 
219 	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
220 			 &vcn, &bbuf->mi);
221 	bbuf->b = b;
222 	if (!b)
223 		return -EINVAL;
224 
225 	if (!b->non_res) {
226 		data_size = le32_to_cpu(b->res.data_size);
227 
228 		if (off >= data_size)
229 			return -EINVAL;
230 
231 		bbuf->buf = (ulong *)resident_data(b);
232 		bbuf->bit = 0;
233 		bbuf->nbits = data_size * 8;
234 
235 		return 0;
236 	}
237 
238 	data_size = le64_to_cpu(b->nres.data_size);
239 	if (WARN_ON(off >= data_size)) {
240 		/* Looks like filesystem error. */
241 		return -EINVAL;
242 	}
243 
244 	valid_size = le64_to_cpu(b->nres.valid_size);
245 
246 	bh = ntfs_bread_run(sbi, &indx->bitmap_run, off);
247 	if (!bh)
248 		return -EIO;
249 
250 	if (IS_ERR(bh))
251 		return PTR_ERR(bh);
252 
253 	bbuf->bh = bh;
254 
255 	if (buffer_locked(bh))
256 		__wait_on_buffer(bh);
257 
258 	lock_buffer(bh);
259 
260 	sb = sbi->sb;
261 	blocksize = sb->s_blocksize;
262 
263 	vbo = off & ~(size_t)sbi->block_mask;
264 
265 	bbuf->new_valid = vbo + blocksize;
266 	if (bbuf->new_valid <= valid_size)
267 		bbuf->new_valid = 0;
268 	else if (bbuf->new_valid > data_size)
269 		bbuf->new_valid = data_size;
270 
271 	if (vbo >= valid_size) {
272 		memset(bh->b_data, 0, blocksize);
273 	} else if (vbo + blocksize > valid_size) {
274 		u32 voff = valid_size & sbi->block_mask;
275 
276 		memset(bh->b_data + voff, 0, blocksize - voff);
277 	}
278 
279 	bbuf->buf = (ulong *)bh->b_data;
280 	bbuf->bit = 8 * (off & ~(size_t)sbi->block_mask);
281 	bbuf->nbits = 8 * blocksize;
282 
283 	return 0;
284 }
285 
286 static void bmp_buf_put(struct bmp_buf *bbuf, bool dirty)
287 {
288 	struct buffer_head *bh = bbuf->bh;
289 	struct ATTRIB *b = bbuf->b;
290 
291 	if (!bh) {
292 		if (b && !b->non_res && dirty)
293 			bbuf->mi->dirty = true;
294 		return;
295 	}
296 
297 	if (!dirty)
298 		goto out;
299 
300 	if (bbuf->new_valid) {
301 		b->nres.valid_size = cpu_to_le64(bbuf->new_valid);
302 		bbuf->mi->dirty = true;
303 	}
304 
305 	set_buffer_uptodate(bh);
306 	mark_buffer_dirty(bh);
307 
308 out:
309 	unlock_buffer(bh);
310 	put_bh(bh);
311 }
312 
313 /*
314  * indx_mark_used - Mark the bit @bit as used.
315  */
316 static int indx_mark_used(struct ntfs_index *indx, struct ntfs_inode *ni,
317 			  size_t bit)
318 {
319 	int err;
320 	struct bmp_buf bbuf;
321 
322 	err = bmp_buf_get(indx, ni, bit, &bbuf);
323 	if (err)
324 		return err;
325 
326 	__set_bit_le(bit - bbuf.bit, bbuf.buf);
327 
328 	bmp_buf_put(&bbuf, true);
329 
330 	return 0;
331 }
332 
333 /*
334  * indx_mark_free - Mark the bit @bit as free.
335  */
336 static int indx_mark_free(struct ntfs_index *indx, struct ntfs_inode *ni,
337 			  size_t bit)
338 {
339 	int err;
340 	struct bmp_buf bbuf;
341 
342 	err = bmp_buf_get(indx, ni, bit, &bbuf);
343 	if (err)
344 		return err;
345 
346 	__clear_bit_le(bit - bbuf.bit, bbuf.buf);
347 
348 	bmp_buf_put(&bbuf, true);
349 
350 	return 0;
351 }
352 
353 /*
354  * scan_nres_bitmap
355  *
356  * If ntfs_readdir calls this function (indx_used_bit -> scan_nres_bitmap),
357  * inode is shared locked and no ni_lock.
358  * Use rw_semaphore for read/write access to bitmap_run.
359  */
360 static int scan_nres_bitmap(struct ntfs_inode *ni, struct ATTRIB *bitmap,
361 			    struct ntfs_index *indx, size_t from,
362 			    bool (*fn)(const ulong *buf, u32 bit, u32 bits,
363 				       size_t *ret),
364 			    size_t *ret)
365 {
366 	struct ntfs_sb_info *sbi = ni->mi.sbi;
367 	struct super_block *sb = sbi->sb;
368 	struct runs_tree *run = &indx->bitmap_run;
369 	struct rw_semaphore *lock = &indx->run_lock;
370 	u32 nbits = sb->s_blocksize * 8;
371 	u32 blocksize = sb->s_blocksize;
372 	u64 valid_size = le64_to_cpu(bitmap->nres.valid_size);
373 	u64 data_size = le64_to_cpu(bitmap->nres.data_size);
374 	sector_t eblock = bytes_to_block(sb, data_size);
375 	size_t vbo = from >> 3;
376 	sector_t blk = (vbo & sbi->cluster_mask) >> sb->s_blocksize_bits;
377 	sector_t vblock = vbo >> sb->s_blocksize_bits;
378 	sector_t blen, block;
379 	CLST lcn, clen, vcn, vcn_next;
380 	size_t idx;
381 	struct buffer_head *bh;
382 	bool ok;
383 
384 	*ret = MINUS_ONE_T;
385 
386 	if (vblock >= eblock)
387 		return 0;
388 
389 	from &= nbits - 1;
390 	vcn = vbo >> sbi->cluster_bits;
391 
392 	down_read(lock);
393 	ok = run_lookup_entry(run, vcn, &lcn, &clen, &idx);
394 	up_read(lock);
395 
396 next_run:
397 	if (!ok) {
398 		int err;
399 		const struct INDEX_NAMES *name = &s_index_names[indx->type];
400 
401 		down_write(lock);
402 		err = attr_load_runs_vcn(ni, ATTR_BITMAP, name->name,
403 					 name->name_len, run, vcn);
404 		up_write(lock);
405 		if (err)
406 			return err;
407 		down_read(lock);
408 		ok = run_lookup_entry(run, vcn, &lcn, &clen, &idx);
409 		up_read(lock);
410 		if (!ok)
411 			return -EINVAL;
412 	}
413 
414 	blen = (sector_t)clen * sbi->blocks_per_cluster;
415 	block = (sector_t)lcn * sbi->blocks_per_cluster;
416 
417 	for (; blk < blen; blk++, from = 0) {
418 		bh = ntfs_bread(sb, block + blk);
419 		if (!bh)
420 			return -EIO;
421 
422 		vbo = (u64)vblock << sb->s_blocksize_bits;
423 		if (vbo >= valid_size) {
424 			memset(bh->b_data, 0, blocksize);
425 		} else if (vbo + blocksize > valid_size) {
426 			u32 voff = valid_size & sbi->block_mask;
427 
428 			memset(bh->b_data + voff, 0, blocksize - voff);
429 		}
430 
431 		if (vbo + blocksize > data_size)
432 			nbits = 8 * (data_size - vbo);
433 
434 		ok = nbits > from ?
435 			     (*fn)((ulong *)bh->b_data, from, nbits, ret) :
436 			     false;
437 		put_bh(bh);
438 
439 		if (ok) {
440 			*ret += 8 * vbo;
441 			return 0;
442 		}
443 
444 		if (++vblock >= eblock) {
445 			*ret = MINUS_ONE_T;
446 			return 0;
447 		}
448 	}
449 	blk = 0;
450 	vcn_next = vcn + clen;
451 	down_read(lock);
452 	ok = run_get_entry(run, ++idx, &vcn, &lcn, &clen) && vcn == vcn_next;
453 	if (!ok)
454 		vcn = vcn_next;
455 	up_read(lock);
456 	goto next_run;
457 }
458 
459 static bool scan_for_free(const ulong *buf, u32 bit, u32 bits, size_t *ret)
460 {
461 	size_t pos = find_next_zero_bit_le(buf, bits, bit);
462 
463 	if (pos >= bits)
464 		return false;
465 	*ret = pos;
466 	return true;
467 }
468 
469 /*
470  * indx_find_free - Look for free bit.
471  *
472  * Return: -1 if no free bits.
473  */
474 static int indx_find_free(struct ntfs_index *indx, struct ntfs_inode *ni,
475 			  size_t *bit, struct ATTRIB **bitmap)
476 {
477 	struct ATTRIB *b;
478 	struct ATTR_LIST_ENTRY *le = NULL;
479 	const struct INDEX_NAMES *in = &s_index_names[indx->type];
480 	int err;
481 
482 	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
483 			 NULL, NULL);
484 
485 	if (!b)
486 		return -ENOENT;
487 
488 	*bitmap = b;
489 	*bit = MINUS_ONE_T;
490 
491 	if (!b->non_res) {
492 		u32 nbits = 8 * le32_to_cpu(b->res.data_size);
493 		size_t pos = find_next_zero_bit_le(resident_data(b), nbits, 0);
494 
495 		if (pos < nbits)
496 			*bit = pos;
497 	} else {
498 		err = scan_nres_bitmap(ni, b, indx, 0, &scan_for_free, bit);
499 
500 		if (err)
501 			return err;
502 	}
503 
504 	return 0;
505 }
506 
507 static bool scan_for_used(const ulong *buf, u32 bit, u32 bits, size_t *ret)
508 {
509 	size_t pos = find_next_bit_le(buf, bits, bit);
510 
511 	if (pos >= bits)
512 		return false;
513 	*ret = pos;
514 	return true;
515 }
516 
517 /*
518  * indx_used_bit - Look for used bit.
519  *
520  * Return: MINUS_ONE_T if no used bits.
521  */
522 int indx_used_bit(struct ntfs_index *indx, struct ntfs_inode *ni, size_t *bit)
523 {
524 	struct ATTRIB *b;
525 	struct ATTR_LIST_ENTRY *le = NULL;
526 	size_t from = *bit;
527 	const struct INDEX_NAMES *in = &s_index_names[indx->type];
528 	int err;
529 
530 	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
531 			 NULL, NULL);
532 
533 	if (!b)
534 		return -ENOENT;
535 
536 	*bit = MINUS_ONE_T;
537 
538 	if (!b->non_res) {
539 		u32 nbits = le32_to_cpu(b->res.data_size) * 8;
540 		size_t pos = find_next_bit_le(resident_data(b), nbits, from);
541 
542 		if (pos < nbits)
543 			*bit = pos;
544 	} else {
545 		err = scan_nres_bitmap(ni, b, indx, from, &scan_for_used, bit);
546 		if (err)
547 			return err;
548 	}
549 
550 	return 0;
551 }
552 
553 /*
554  * hdr_find_split
555  *
556  * Find a point at which the index allocation buffer would like to be split.
557  * NOTE: This function should never return 'END' entry NULL returns on error.
558  */
559 static const struct NTFS_DE *hdr_find_split(const struct INDEX_HDR *hdr)
560 {
561 	size_t o;
562 	const struct NTFS_DE *e = hdr_first_de(hdr);
563 	u32 used_2 = le32_to_cpu(hdr->used) >> 1;
564 	u16 esize;
565 
566 	if (!e || de_is_last(e))
567 		return NULL;
568 
569 	esize = le16_to_cpu(e->size);
570 	for (o = le32_to_cpu(hdr->de_off) + esize; o < used_2; o += esize) {
571 		const struct NTFS_DE *p = e;
572 
573 		e = Add2Ptr(hdr, o);
574 
575 		/* We must not return END entry. */
576 		if (de_is_last(e))
577 			return p;
578 
579 		esize = le16_to_cpu(e->size);
580 	}
581 
582 	return e;
583 }
584 
585 /*
586  * hdr_insert_head - Insert some entries at the beginning of the buffer.
587  *
588  * It is used to insert entries into a newly-created buffer.
589  */
590 static const struct NTFS_DE *hdr_insert_head(struct INDEX_HDR *hdr,
591 					     const void *ins, u32 ins_bytes)
592 {
593 	u32 to_move;
594 	struct NTFS_DE *e = hdr_first_de(hdr);
595 	u32 used = le32_to_cpu(hdr->used);
596 
597 	if (!e)
598 		return NULL;
599 
600 	/* Now we just make room for the inserted entries and jam it in. */
601 	to_move = used - le32_to_cpu(hdr->de_off);
602 	memmove(Add2Ptr(e, ins_bytes), e, to_move);
603 	memcpy(e, ins, ins_bytes);
604 	hdr->used = cpu_to_le32(used + ins_bytes);
605 
606 	return e;
607 }
608 
609 /*
610  * index_hdr_check
611  *
612  * return true if INDEX_HDR is valid
613  */
614 static bool index_hdr_check(const struct INDEX_HDR *hdr, u32 bytes)
615 {
616 	u32 end = le32_to_cpu(hdr->used);
617 	u32 tot = le32_to_cpu(hdr->total);
618 	u32 off = le32_to_cpu(hdr->de_off);
619 
620 	if (!IS_ALIGNED(off, 8) || tot > bytes || end > tot ||
621 	    off + sizeof(struct NTFS_DE) > end) {
622 		/* incorrect index buffer. */
623 		return false;
624 	}
625 
626 	return true;
627 }
628 
629 /*
630  * index_buf_check
631  *
632  * return true if INDEX_BUFFER seems is valid
633  */
634 static bool index_buf_check(const struct INDEX_BUFFER *ib, u32 bytes,
635 			    const CLST *vbn)
636 {
637 	const struct NTFS_RECORD_HEADER *rhdr = &ib->rhdr;
638 	u16 fo = le16_to_cpu(rhdr->fix_off);
639 	u16 fn = le16_to_cpu(rhdr->fix_num);
640 
641 	if (bytes <= offsetof(struct INDEX_BUFFER, ihdr) ||
642 	    rhdr->sign != NTFS_INDX_SIGNATURE ||
643 	    fo < sizeof(struct INDEX_BUFFER)
644 	    /* Check index buffer vbn. */
645 	    || (vbn && *vbn != le64_to_cpu(ib->vbn)) || (fo % sizeof(short)) ||
646 	    fo + fn * sizeof(short) >= bytes ||
647 	    fn != ((bytes >> SECTOR_SHIFT) + 1)) {
648 		/* incorrect index buffer. */
649 		return false;
650 	}
651 
652 	return index_hdr_check(&ib->ihdr,
653 			       bytes - offsetof(struct INDEX_BUFFER, ihdr));
654 }
655 
656 void fnd_clear(struct ntfs_fnd *fnd)
657 {
658 	int i;
659 
660 	for (i = fnd->level - 1; i >= 0; i--) {
661 		struct indx_node *n = fnd->nodes[i];
662 
663 		if (!n)
664 			continue;
665 
666 		put_indx_node(n);
667 		fnd->nodes[i] = NULL;
668 	}
669 	fnd->level = 0;
670 	fnd->root_de = NULL;
671 }
672 
673 static int fnd_push(struct ntfs_fnd *fnd, struct indx_node *n,
674 		    struct NTFS_DE *e)
675 {
676 	int i = fnd->level;
677 
678 	if (i < 0 || i >= ARRAY_SIZE(fnd->nodes))
679 		return -EINVAL;
680 	fnd->nodes[i] = n;
681 	fnd->de[i] = e;
682 	fnd->level += 1;
683 	return 0;
684 }
685 
686 static struct indx_node *fnd_pop(struct ntfs_fnd *fnd)
687 {
688 	struct indx_node *n;
689 	int i = fnd->level;
690 
691 	i -= 1;
692 	n = fnd->nodes[i];
693 	fnd->nodes[i] = NULL;
694 	fnd->level = i;
695 
696 	return n;
697 }
698 
699 static bool fnd_is_empty(struct ntfs_fnd *fnd)
700 {
701 	if (!fnd->level)
702 		return !fnd->root_de;
703 
704 	return !fnd->de[fnd->level - 1];
705 }
706 
707 /*
708  * hdr_find_e - Locate an entry the index buffer.
709  *
710  * If no matching entry is found, it returns the first entry which is greater
711  * than the desired entry If the search key is greater than all the entries the
712  * buffer, it returns the 'end' entry. This function does a binary search of the
713  * current index buffer, for the first entry that is <= to the search value.
714  *
715  * Return: NULL if error.
716  */
717 static struct NTFS_DE *hdr_find_e(const struct ntfs_index *indx,
718 				  const struct INDEX_HDR *hdr, const void *key,
719 				  size_t key_len, const void *ctx, int *diff)
720 {
721 	struct NTFS_DE *e, *found = NULL;
722 	NTFS_CMP_FUNC cmp = indx->cmp;
723 	int min_idx = 0, mid_idx, max_idx = 0;
724 	int diff2;
725 	int table_size = 8;
726 	u32 e_size, e_key_len;
727 	u32 end = le32_to_cpu(hdr->used);
728 	u32 off = le32_to_cpu(hdr->de_off);
729 	u32 total = le32_to_cpu(hdr->total);
730 	u16 offs[128];
731 
732 	if (unlikely(!cmp))
733 		return NULL;
734 
735 fill_table:
736 	if (end > total)
737 		return NULL;
738 
739 	if (off + sizeof(struct NTFS_DE) > end)
740 		return NULL;
741 
742 	e = Add2Ptr(hdr, off);
743 	e_size = le16_to_cpu(e->size);
744 
745 	if (e_size < sizeof(struct NTFS_DE) || off + e_size > end)
746 		return NULL;
747 
748 	if (!de_is_last(e)) {
749 		offs[max_idx] = off;
750 		off += e_size;
751 
752 		max_idx++;
753 		if (max_idx < table_size)
754 			goto fill_table;
755 
756 		max_idx--;
757 	}
758 
759 binary_search:
760 	e_key_len = le16_to_cpu(e->key_size);
761 
762 	diff2 = (*cmp)(key, key_len, e + 1, e_key_len, ctx);
763 	if (diff2 > 0) {
764 		if (found) {
765 			min_idx = mid_idx + 1;
766 		} else {
767 			if (de_is_last(e))
768 				return NULL;
769 
770 			max_idx = 0;
771 			table_size = min(table_size * 2, (int)ARRAY_SIZE(offs));
772 			goto fill_table;
773 		}
774 	} else if (diff2 < 0) {
775 		if (found)
776 			max_idx = mid_idx - 1;
777 		else
778 			max_idx--;
779 
780 		found = e;
781 	} else {
782 		*diff = 0;
783 		return e;
784 	}
785 
786 	if (min_idx > max_idx) {
787 		*diff = -1;
788 		return found;
789 	}
790 
791 	mid_idx = (min_idx + max_idx) >> 1;
792 	e = Add2Ptr(hdr, offs[mid_idx]);
793 
794 	goto binary_search;
795 }
796 
797 /*
798  * hdr_insert_de - Insert an index entry into the buffer.
799  *
800  * 'before' should be a pointer previously returned from hdr_find_e.
801  */
802 static struct NTFS_DE *hdr_insert_de(const struct ntfs_index *indx,
803 				     struct INDEX_HDR *hdr,
804 				     const struct NTFS_DE *de,
805 				     struct NTFS_DE *before, const void *ctx)
806 {
807 	int diff;
808 	size_t off = PtrOffset(hdr, before);
809 	u32 used = le32_to_cpu(hdr->used);
810 	u32 total = le32_to_cpu(hdr->total);
811 	u16 de_size = le16_to_cpu(de->size);
812 
813 	/* First, check to see if there's enough room. */
814 	if (used + de_size > total)
815 		return NULL;
816 
817 	/* We know there's enough space, so we know we'll succeed. */
818 	if (before) {
819 		/* Check that before is inside Index. */
820 		if (off >= used || off < le32_to_cpu(hdr->de_off) ||
821 		    off + le16_to_cpu(before->size) > total) {
822 			return NULL;
823 		}
824 		goto ok;
825 	}
826 	/* No insert point is applied. Get it manually. */
827 	before = hdr_find_e(indx, hdr, de + 1, le16_to_cpu(de->key_size), ctx,
828 			    &diff);
829 	if (!before)
830 		return NULL;
831 	off = PtrOffset(hdr, before);
832 
833 ok:
834 	/* Now we just make room for the entry and jam it in. */
835 	memmove(Add2Ptr(before, de_size), before, used - off);
836 
837 	hdr->used = cpu_to_le32(used + de_size);
838 	memcpy(before, de, de_size);
839 
840 	return before;
841 }
842 
843 /*
844  * hdr_delete_de - Remove an entry from the index buffer.
845  */
846 static inline struct NTFS_DE *hdr_delete_de(struct INDEX_HDR *hdr,
847 					    struct NTFS_DE *re)
848 {
849 	u32 used = le32_to_cpu(hdr->used);
850 	u16 esize = le16_to_cpu(re->size);
851 	u32 off = PtrOffset(hdr, re);
852 	int bytes = used - (off + esize);
853 
854 	/* check INDEX_HDR valid before using INDEX_HDR */
855 	if (!check_index_header(hdr, le32_to_cpu(hdr->total)))
856 		return NULL;
857 
858 	if (off >= used || esize < sizeof(struct NTFS_DE) ||
859 	    bytes < sizeof(struct NTFS_DE))
860 		return NULL;
861 
862 	hdr->used = cpu_to_le32(used - esize);
863 	memmove(re, Add2Ptr(re, esize), bytes);
864 
865 	return re;
866 }
867 
868 void indx_clear(struct ntfs_index *indx)
869 {
870 	run_close(&indx->alloc_run);
871 	run_close(&indx->bitmap_run);
872 }
873 
874 int indx_init(struct ntfs_index *indx, struct ntfs_sb_info *sbi,
875 	      const struct ATTRIB *attr, enum index_mutex_classed type)
876 {
877 	u32 t32;
878 	const struct INDEX_ROOT *root = resident_data(attr);
879 
880 	t32 = le32_to_cpu(attr->res.data_size);
881 	if (t32 <= offsetof(struct INDEX_ROOT, ihdr) ||
882 	    !index_hdr_check(&root->ihdr,
883 			     t32 - offsetof(struct INDEX_ROOT, ihdr))) {
884 		goto out;
885 	}
886 
887 	/* Check root fields. */
888 	if (!root->index_block_clst)
889 		goto out;
890 
891 	indx->type = type;
892 	indx->idx2vbn_bits = __ffs(root->index_block_clst);
893 
894 	t32 = le32_to_cpu(root->index_block_size);
895 	indx->index_bits = blksize_bits(t32);
896 
897 	/* Check index record size. */
898 	if (t32 < sbi->cluster_size) {
899 		/* Index record is smaller than a cluster, use 512 blocks. */
900 		if (t32 != root->index_block_clst * SECTOR_SIZE)
901 			goto out;
902 
903 		/* Check alignment to a cluster. */
904 		if ((sbi->cluster_size >> SECTOR_SHIFT) &
905 		    (root->index_block_clst - 1)) {
906 			goto out;
907 		}
908 
909 		indx->vbn2vbo_bits = SECTOR_SHIFT;
910 	} else {
911 		/* Index record must be a multiple of cluster size. */
912 		if (t32 != root->index_block_clst << sbi->cluster_bits)
913 			goto out;
914 
915 		indx->vbn2vbo_bits = sbi->cluster_bits;
916 	}
917 
918 	init_rwsem(&indx->run_lock);
919 
920 	indx->cmp = get_cmp_func(root);
921 	if (!indx->cmp)
922 		goto out;
923 
924 	return 0;
925 
926 out:
927 	ntfs_set_state(sbi, NTFS_DIRTY_DIRTY);
928 	return -EINVAL;
929 }
930 
931 static struct indx_node *indx_new(struct ntfs_index *indx,
932 				  struct ntfs_inode *ni, CLST vbn,
933 				  const __le64 *sub_vbn)
934 {
935 	int err;
936 	struct NTFS_DE *e;
937 	struct indx_node *r;
938 	struct INDEX_HDR *hdr;
939 	struct INDEX_BUFFER *index;
940 	u64 vbo = (u64)vbn << indx->vbn2vbo_bits;
941 	u32 bytes = 1u << indx->index_bits;
942 	u16 fn;
943 	u32 eo;
944 
945 	r = kzalloc(sizeof(struct indx_node), GFP_NOFS);
946 	if (!r)
947 		return ERR_PTR(-ENOMEM);
948 
949 	index = kzalloc(bytes, GFP_NOFS);
950 	if (!index) {
951 		kfree(r);
952 		return ERR_PTR(-ENOMEM);
953 	}
954 
955 	err = ntfs_get_bh(ni->mi.sbi, &indx->alloc_run, vbo, bytes, &r->nb);
956 
957 	if (err) {
958 		kfree(index);
959 		kfree(r);
960 		return ERR_PTR(err);
961 	}
962 
963 	/* Create header. */
964 	index->rhdr.sign = NTFS_INDX_SIGNATURE;
965 	index->rhdr.fix_off = cpu_to_le16(sizeof(struct INDEX_BUFFER)); // 0x28
966 	fn = (bytes >> SECTOR_SHIFT) + 1; // 9
967 	index->rhdr.fix_num = cpu_to_le16(fn);
968 	index->vbn = cpu_to_le64(vbn);
969 	hdr = &index->ihdr;
970 	eo = ALIGN(sizeof(struct INDEX_BUFFER) + fn * sizeof(short), 8);
971 	hdr->de_off = cpu_to_le32(eo);
972 
973 	e = Add2Ptr(hdr, eo);
974 
975 	if (sub_vbn) {
976 		e->flags = NTFS_IE_LAST | NTFS_IE_HAS_SUBNODES;
977 		e->size = cpu_to_le16(sizeof(struct NTFS_DE) + sizeof(u64));
978 		hdr->used =
979 			cpu_to_le32(eo + sizeof(struct NTFS_DE) + sizeof(u64));
980 		de_set_vbn_le(e, *sub_vbn);
981 		hdr->flags = 1;
982 	} else {
983 		e->size = cpu_to_le16(sizeof(struct NTFS_DE));
984 		hdr->used = cpu_to_le32(eo + sizeof(struct NTFS_DE));
985 		e->flags = NTFS_IE_LAST;
986 	}
987 
988 	hdr->total = cpu_to_le32(bytes - offsetof(struct INDEX_BUFFER, ihdr));
989 
990 	r->index = index;
991 	return r;
992 }
993 
994 struct INDEX_ROOT *indx_get_root(struct ntfs_index *indx, struct ntfs_inode *ni,
995 				 struct ATTRIB **attr, struct mft_inode **mi)
996 {
997 	struct ATTR_LIST_ENTRY *le = NULL;
998 	struct ATTRIB *a;
999 	const struct INDEX_NAMES *in = &s_index_names[indx->type];
1000 	struct INDEX_ROOT *root;
1001 
1002 	a = ni_find_attr(ni, NULL, &le, ATTR_ROOT, in->name, in->name_len, NULL,
1003 			 mi);
1004 	if (!a)
1005 		return NULL;
1006 
1007 	if (attr)
1008 		*attr = a;
1009 
1010 	root = resident_data_ex(a, sizeof(struct INDEX_ROOT));
1011 
1012 	/* length check */
1013 	if (root &&
1014 	    offsetof(struct INDEX_ROOT, ihdr) + le32_to_cpu(root->ihdr.used) >
1015 		    le32_to_cpu(a->res.data_size)) {
1016 		return NULL;
1017 	}
1018 
1019 	return root;
1020 }
1021 
1022 static int indx_write(struct ntfs_index *indx, struct ntfs_inode *ni,
1023 		      struct indx_node *node, int sync)
1024 {
1025 	struct INDEX_BUFFER *ib = node->index;
1026 
1027 	return ntfs_write_bh(ni->mi.sbi, &ib->rhdr, &node->nb, sync);
1028 }
1029 
1030 /*
1031  * indx_read
1032  *
1033  * If ntfs_readdir calls this function
1034  * inode is shared locked and no ni_lock.
1035  * Use rw_semaphore for read/write access to alloc_run.
1036  */
1037 int indx_read(struct ntfs_index *indx, struct ntfs_inode *ni, CLST vbn,
1038 	      struct indx_node **node)
1039 {
1040 	int err;
1041 	struct INDEX_BUFFER *ib;
1042 	struct runs_tree *run = &indx->alloc_run;
1043 	struct rw_semaphore *lock = &indx->run_lock;
1044 	u64 vbo = (u64)vbn << indx->vbn2vbo_bits;
1045 	u32 bytes = 1u << indx->index_bits;
1046 	struct indx_node *in = *node;
1047 	const struct INDEX_NAMES *name;
1048 
1049 	if (!in) {
1050 		in = kzalloc(sizeof(struct indx_node), GFP_NOFS);
1051 		if (!in)
1052 			return -ENOMEM;
1053 	} else {
1054 		nb_put(&in->nb);
1055 	}
1056 
1057 	ib = in->index;
1058 	if (!ib) {
1059 		ib = kmalloc(bytes, GFP_NOFS);
1060 		if (!ib) {
1061 			err = -ENOMEM;
1062 			goto out;
1063 		}
1064 	}
1065 
1066 	down_read(lock);
1067 	err = ntfs_read_bh(ni->mi.sbi, run, vbo, &ib->rhdr, bytes, &in->nb);
1068 	up_read(lock);
1069 	if (!err)
1070 		goto ok;
1071 
1072 	if (err == -E_NTFS_FIXUP)
1073 		goto ok;
1074 
1075 	if (err != -ENOENT)
1076 		goto out;
1077 
1078 	name = &s_index_names[indx->type];
1079 	down_write(lock);
1080 	err = attr_load_runs_range(ni, ATTR_ALLOC, name->name, name->name_len,
1081 				   run, vbo, vbo + bytes);
1082 	up_write(lock);
1083 	if (err)
1084 		goto out;
1085 
1086 	down_read(lock);
1087 	err = ntfs_read_bh(ni->mi.sbi, run, vbo, &ib->rhdr, bytes, &in->nb);
1088 	up_read(lock);
1089 	if (err == -E_NTFS_FIXUP)
1090 		goto ok;
1091 
1092 	if (err)
1093 		goto out;
1094 
1095 ok:
1096 	if (!index_buf_check(ib, bytes, &vbn)) {
1097 		ntfs_inode_err(&ni->vfs_inode, "directory corrupted");
1098 		ntfs_set_state(ni->mi.sbi, NTFS_DIRTY_ERROR);
1099 		err = -EINVAL;
1100 		goto out;
1101 	}
1102 
1103 	if (err == -E_NTFS_FIXUP) {
1104 		ntfs_write_bh(ni->mi.sbi, &ib->rhdr, &in->nb, 0);
1105 		err = 0;
1106 	}
1107 
1108 	/* check for index header length */
1109 	if (offsetof(struct INDEX_BUFFER, ihdr) + le32_to_cpu(ib->ihdr.used) >
1110 	    bytes) {
1111 		err = -EINVAL;
1112 		goto out;
1113 	}
1114 
1115 	in->index = ib;
1116 	*node = in;
1117 
1118 out:
1119 	if (err == -E_NTFS_CORRUPT) {
1120 		ntfs_inode_err(&ni->vfs_inode, "directory corrupted");
1121 		ntfs_set_state(ni->mi.sbi, NTFS_DIRTY_ERROR);
1122 		err = -EINVAL;
1123 	}
1124 
1125 	if (ib != in->index)
1126 		kfree(ib);
1127 
1128 	if (*node != in) {
1129 		nb_put(&in->nb);
1130 		kfree(in);
1131 	}
1132 
1133 	return err;
1134 }
1135 
1136 /*
1137  * indx_find - Scan NTFS directory for given entry.
1138  */
1139 int indx_find(struct ntfs_index *indx, struct ntfs_inode *ni,
1140 	      const struct INDEX_ROOT *root, const void *key, size_t key_len,
1141 	      const void *ctx, int *diff, struct NTFS_DE **entry,
1142 	      struct ntfs_fnd *fnd)
1143 {
1144 	int err;
1145 	struct NTFS_DE *e;
1146 	struct indx_node *node;
1147 
1148 	if (!root)
1149 		root = indx_get_root(&ni->dir, ni, NULL, NULL);
1150 
1151 	if (!root) {
1152 		/* Should not happen. */
1153 		return -EINVAL;
1154 	}
1155 
1156 	/* Check cache. */
1157 	e = fnd->level ? fnd->de[fnd->level - 1] : fnd->root_de;
1158 	if (e && !de_is_last(e) &&
1159 	    !(*indx->cmp)(key, key_len, e + 1, le16_to_cpu(e->key_size), ctx)) {
1160 		*entry = e;
1161 		*diff = 0;
1162 		return 0;
1163 	}
1164 
1165 	/* Soft finder reset. */
1166 	fnd_clear(fnd);
1167 
1168 	/* Lookup entry that is <= to the search value. */
1169 	e = hdr_find_e(indx, &root->ihdr, key, key_len, ctx, diff);
1170 	if (!e)
1171 		return -EINVAL;
1172 
1173 	fnd->root_de = e;
1174 
1175 	for (;;) {
1176 		node = NULL;
1177 		if (*diff >= 0 || !de_has_vcn_ex(e))
1178 			break;
1179 
1180 		/* Read next level. */
1181 		err = indx_read(indx, ni, de_get_vbn(e), &node);
1182 		if (err) {
1183 			/* io error? */
1184 			return err;
1185 		}
1186 
1187 		/* Lookup entry that is <= to the search value. */
1188 		e = hdr_find_e(indx, &node->index->ihdr, key, key_len, ctx,
1189 			       diff);
1190 		if (!e) {
1191 			put_indx_node(node);
1192 			return -EINVAL;
1193 		}
1194 
1195 		fnd_push(fnd, node, e);
1196 	}
1197 
1198 	*entry = e;
1199 	return 0;
1200 }
1201 
1202 int indx_find_sort(struct ntfs_index *indx, struct ntfs_inode *ni,
1203 		   const struct INDEX_ROOT *root, struct NTFS_DE **entry,
1204 		   struct ntfs_fnd *fnd)
1205 {
1206 	int err;
1207 	struct indx_node *n = NULL;
1208 	struct NTFS_DE *e;
1209 	size_t iter = 0;
1210 	int level = fnd->level;
1211 
1212 	if (!*entry) {
1213 		/* Start find. */
1214 		e = hdr_first_de(&root->ihdr);
1215 		if (!e)
1216 			return 0;
1217 		fnd_clear(fnd);
1218 		fnd->root_de = e;
1219 	} else if (!level) {
1220 		if (de_is_last(fnd->root_de)) {
1221 			*entry = NULL;
1222 			return 0;
1223 		}
1224 
1225 		e = hdr_next_de(&root->ihdr, fnd->root_de);
1226 		if (!e)
1227 			return -EINVAL;
1228 		fnd->root_de = e;
1229 	} else {
1230 		n = fnd->nodes[level - 1];
1231 		e = fnd->de[level - 1];
1232 
1233 		if (de_is_last(e))
1234 			goto pop_level;
1235 
1236 		e = hdr_next_de(&n->index->ihdr, e);
1237 		if (!e)
1238 			return -EINVAL;
1239 
1240 		fnd->de[level - 1] = e;
1241 	}
1242 
1243 	/* Just to avoid tree cycle. */
1244 next_iter:
1245 	if (iter++ >= 1000)
1246 		return -EINVAL;
1247 
1248 	while (de_has_vcn_ex(e)) {
1249 		if (le16_to_cpu(e->size) <
1250 		    sizeof(struct NTFS_DE) + sizeof(u64)) {
1251 			if (n) {
1252 				fnd_pop(fnd);
1253 				kfree(n);
1254 			}
1255 			return -EINVAL;
1256 		}
1257 
1258 		/* Read next level. */
1259 		err = indx_read(indx, ni, de_get_vbn(e), &n);
1260 		if (err)
1261 			return err;
1262 
1263 		/* Try next level. */
1264 		e = hdr_first_de(&n->index->ihdr);
1265 		if (!e) {
1266 			kfree(n);
1267 			return -EINVAL;
1268 		}
1269 
1270 		fnd_push(fnd, n, e);
1271 	}
1272 
1273 	if (le16_to_cpu(e->size) > sizeof(struct NTFS_DE)) {
1274 		*entry = e;
1275 		return 0;
1276 	}
1277 
1278 pop_level:
1279 	for (;;) {
1280 		if (!de_is_last(e))
1281 			goto next_iter;
1282 
1283 		/* Pop one level. */
1284 		if (n) {
1285 			fnd_pop(fnd);
1286 			kfree(n);
1287 		}
1288 
1289 		level = fnd->level;
1290 
1291 		if (level) {
1292 			n = fnd->nodes[level - 1];
1293 			e = fnd->de[level - 1];
1294 		} else if (fnd->root_de) {
1295 			n = NULL;
1296 			e = fnd->root_de;
1297 			fnd->root_de = NULL;
1298 		} else {
1299 			*entry = NULL;
1300 			return 0;
1301 		}
1302 
1303 		if (le16_to_cpu(e->size) > sizeof(struct NTFS_DE)) {
1304 			*entry = e;
1305 			if (!fnd->root_de)
1306 				fnd->root_de = e;
1307 			return 0;
1308 		}
1309 	}
1310 }
1311 
1312 int indx_find_raw(struct ntfs_index *indx, struct ntfs_inode *ni,
1313 		  const struct INDEX_ROOT *root, struct NTFS_DE **entry,
1314 		  size_t *off, struct ntfs_fnd *fnd)
1315 {
1316 	int err;
1317 	struct indx_node *n = NULL;
1318 	struct NTFS_DE *e = NULL;
1319 	struct NTFS_DE *e2;
1320 	size_t bit;
1321 	CLST next_used_vbn;
1322 	CLST next_vbn;
1323 	u32 record_size = ni->mi.sbi->record_size;
1324 
1325 	/* Use non sorted algorithm. */
1326 	if (!*entry) {
1327 		/* This is the first call. */
1328 		e = hdr_first_de(&root->ihdr);
1329 		if (!e)
1330 			return 0;
1331 		fnd_clear(fnd);
1332 		fnd->root_de = e;
1333 
1334 		/* The first call with setup of initial element. */
1335 		if (*off >= record_size) {
1336 			next_vbn = (((*off - record_size) >> indx->index_bits))
1337 				   << indx->idx2vbn_bits;
1338 			/* Jump inside cycle 'for'. */
1339 			goto next;
1340 		}
1341 
1342 		/* Start enumeration from root. */
1343 		*off = 0;
1344 	} else if (!fnd->root_de)
1345 		return -EINVAL;
1346 
1347 	for (;;) {
1348 		/* Check if current entry can be used. */
1349 		if (e && le16_to_cpu(e->size) > sizeof(struct NTFS_DE))
1350 			goto ok;
1351 
1352 		if (!fnd->level) {
1353 			/* Continue to enumerate root. */
1354 			if (!de_is_last(fnd->root_de)) {
1355 				e = hdr_next_de(&root->ihdr, fnd->root_de);
1356 				if (!e)
1357 					return -EINVAL;
1358 				fnd->root_de = e;
1359 				continue;
1360 			}
1361 
1362 			/* Start to enumerate indexes from 0. */
1363 			next_vbn = 0;
1364 		} else {
1365 			/* Continue to enumerate indexes. */
1366 			e2 = fnd->de[fnd->level - 1];
1367 
1368 			n = fnd->nodes[fnd->level - 1];
1369 
1370 			if (!de_is_last(e2)) {
1371 				e = hdr_next_de(&n->index->ihdr, e2);
1372 				if (!e)
1373 					return -EINVAL;
1374 				fnd->de[fnd->level - 1] = e;
1375 				continue;
1376 			}
1377 
1378 			/* Continue with next index. */
1379 			next_vbn = le64_to_cpu(n->index->vbn) +
1380 				   root->index_block_clst;
1381 		}
1382 
1383 next:
1384 		/* Release current index. */
1385 		if (n) {
1386 			fnd_pop(fnd);
1387 			put_indx_node(n);
1388 			n = NULL;
1389 		}
1390 
1391 		/* Skip all free indexes. */
1392 		bit = next_vbn >> indx->idx2vbn_bits;
1393 		err = indx_used_bit(indx, ni, &bit);
1394 		if (err == -ENOENT || bit == MINUS_ONE_T) {
1395 			/* No used indexes. */
1396 			*entry = NULL;
1397 			return 0;
1398 		}
1399 
1400 		next_used_vbn = bit << indx->idx2vbn_bits;
1401 
1402 		/* Read buffer into memory. */
1403 		err = indx_read(indx, ni, next_used_vbn, &n);
1404 		if (err)
1405 			return err;
1406 
1407 		e = hdr_first_de(&n->index->ihdr);
1408 		fnd_push(fnd, n, e);
1409 		if (!e)
1410 			return -EINVAL;
1411 	}
1412 
1413 ok:
1414 	/* Return offset to restore enumerator if necessary. */
1415 	if (!n) {
1416 		/* 'e' points in root, */
1417 		*off = PtrOffset(&root->ihdr, e);
1418 	} else {
1419 		/* 'e' points in index, */
1420 		*off = (le64_to_cpu(n->index->vbn) << indx->vbn2vbo_bits) +
1421 		       record_size + PtrOffset(&n->index->ihdr, e);
1422 	}
1423 
1424 	*entry = e;
1425 	return 0;
1426 }
1427 
1428 /*
1429  * indx_create_allocate - Create "Allocation + Bitmap" attributes.
1430  */
1431 static int indx_create_allocate(struct ntfs_index *indx, struct ntfs_inode *ni,
1432 				CLST *vbn)
1433 {
1434 	int err;
1435 	struct ntfs_sb_info *sbi = ni->mi.sbi;
1436 	struct ATTRIB *bitmap;
1437 	struct ATTRIB *alloc;
1438 	u32 data_size = 1u << indx->index_bits;
1439 	u32 alloc_size = ntfs_up_cluster(sbi, data_size);
1440 	CLST len = alloc_size >> sbi->cluster_bits;
1441 	const struct INDEX_NAMES *in = &s_index_names[indx->type];
1442 	CLST alen;
1443 	struct runs_tree run;
1444 
1445 	run_init(&run);
1446 
1447 	err = attr_allocate_clusters(sbi, &run, 0, 0, len, NULL, ALLOCATE_DEF,
1448 				     &alen, 0, NULL, NULL);
1449 	if (err)
1450 		goto out;
1451 
1452 	err = ni_insert_nonresident(ni, ATTR_ALLOC, in->name, in->name_len,
1453 				    &run, 0, len, 0, &alloc, NULL, NULL);
1454 	if (err)
1455 		goto out1;
1456 
1457 	alloc->nres.valid_size = alloc->nres.data_size = cpu_to_le64(data_size);
1458 
1459 	err = ni_insert_resident(ni, bitmap_size(1), ATTR_BITMAP, in->name,
1460 				 in->name_len, &bitmap, NULL, NULL);
1461 	if (err)
1462 		goto out2;
1463 
1464 	if (in->name == I30_NAME) {
1465 		i_size_write(&ni->vfs_inode, data_size);
1466 		inode_set_bytes(&ni->vfs_inode, alloc_size);
1467 	}
1468 
1469 	memcpy(&indx->alloc_run, &run, sizeof(run));
1470 
1471 	*vbn = 0;
1472 
1473 	return 0;
1474 
1475 out2:
1476 	mi_remove_attr(NULL, &ni->mi, alloc);
1477 
1478 out1:
1479 	run_deallocate(sbi, &run, false);
1480 
1481 out:
1482 	return err;
1483 }
1484 
1485 /*
1486  * indx_add_allocate - Add clusters to index.
1487  */
1488 static int indx_add_allocate(struct ntfs_index *indx, struct ntfs_inode *ni,
1489 			     CLST *vbn)
1490 {
1491 	int err;
1492 	size_t bit;
1493 	u64 data_size;
1494 	u64 bmp_size, bmp_size_v;
1495 	struct ATTRIB *bmp, *alloc;
1496 	struct mft_inode *mi;
1497 	const struct INDEX_NAMES *in = &s_index_names[indx->type];
1498 
1499 	err = indx_find_free(indx, ni, &bit, &bmp);
1500 	if (err)
1501 		goto out1;
1502 
1503 	if (bit != MINUS_ONE_T) {
1504 		bmp = NULL;
1505 	} else {
1506 		if (bmp->non_res) {
1507 			bmp_size = le64_to_cpu(bmp->nres.data_size);
1508 			bmp_size_v = le64_to_cpu(bmp->nres.valid_size);
1509 		} else {
1510 			bmp_size = bmp_size_v = le32_to_cpu(bmp->res.data_size);
1511 		}
1512 
1513 		bit = bmp_size << 3;
1514 	}
1515 
1516 	data_size = (u64)(bit + 1) << indx->index_bits;
1517 
1518 	if (bmp) {
1519 		/* Increase bitmap. */
1520 		err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
1521 				    &indx->bitmap_run, bitmap_size(bit + 1),
1522 				    NULL, true, NULL);
1523 		if (err)
1524 			goto out1;
1525 	}
1526 
1527 	alloc = ni_find_attr(ni, NULL, NULL, ATTR_ALLOC, in->name, in->name_len,
1528 			     NULL, &mi);
1529 	if (!alloc) {
1530 		err = -EINVAL;
1531 		if (bmp)
1532 			goto out2;
1533 		goto out1;
1534 	}
1535 
1536 	/* Increase allocation. */
1537 	err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
1538 			    &indx->alloc_run, data_size, &data_size, true,
1539 			    NULL);
1540 	if (err) {
1541 		if (bmp)
1542 			goto out2;
1543 		goto out1;
1544 	}
1545 
1546 	if (in->name == I30_NAME)
1547 		i_size_write(&ni->vfs_inode, data_size);
1548 
1549 	*vbn = bit << indx->idx2vbn_bits;
1550 
1551 	return 0;
1552 
1553 out2:
1554 	/* Ops. No space? */
1555 	attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
1556 		      &indx->bitmap_run, bmp_size, &bmp_size_v, false, NULL);
1557 
1558 out1:
1559 	return err;
1560 }
1561 
1562 /*
1563  * indx_insert_into_root - Attempt to insert an entry into the index root.
1564  *
1565  * @undo - True if we undoing previous remove.
1566  * If necessary, it will twiddle the index b-tree.
1567  */
1568 static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
1569 				 const struct NTFS_DE *new_de,
1570 				 struct NTFS_DE *root_de, const void *ctx,
1571 				 struct ntfs_fnd *fnd, bool undo)
1572 {
1573 	int err = 0;
1574 	struct NTFS_DE *e, *e0, *re;
1575 	struct mft_inode *mi;
1576 	struct ATTRIB *attr;
1577 	struct INDEX_HDR *hdr;
1578 	struct indx_node *n;
1579 	CLST new_vbn;
1580 	__le64 *sub_vbn, t_vbn;
1581 	u16 new_de_size;
1582 	u32 hdr_used, hdr_total, asize, to_move;
1583 	u32 root_size, new_root_size;
1584 	struct ntfs_sb_info *sbi;
1585 	int ds_root;
1586 	struct INDEX_ROOT *root, *a_root;
1587 
1588 	/* Get the record this root placed in. */
1589 	root = indx_get_root(indx, ni, &attr, &mi);
1590 	if (!root)
1591 		return -EINVAL;
1592 
1593 	/*
1594 	 * Try easy case:
1595 	 * hdr_insert_de will succeed if there's
1596 	 * room the root for the new entry.
1597 	 */
1598 	hdr = &root->ihdr;
1599 	sbi = ni->mi.sbi;
1600 	new_de_size = le16_to_cpu(new_de->size);
1601 	hdr_used = le32_to_cpu(hdr->used);
1602 	hdr_total = le32_to_cpu(hdr->total);
1603 	asize = le32_to_cpu(attr->size);
1604 	root_size = le32_to_cpu(attr->res.data_size);
1605 
1606 	ds_root = new_de_size + hdr_used - hdr_total;
1607 
1608 	/* If 'undo' is set then reduce requirements. */
1609 	if ((undo || asize + ds_root < sbi->max_bytes_per_attr) &&
1610 	    mi_resize_attr(mi, attr, ds_root)) {
1611 		hdr->total = cpu_to_le32(hdr_total + ds_root);
1612 		e = hdr_insert_de(indx, hdr, new_de, root_de, ctx);
1613 		WARN_ON(!e);
1614 		fnd_clear(fnd);
1615 		fnd->root_de = e;
1616 
1617 		return 0;
1618 	}
1619 
1620 	/* Make a copy of root attribute to restore if error. */
1621 	a_root = kmemdup(attr, asize, GFP_NOFS);
1622 	if (!a_root)
1623 		return -ENOMEM;
1624 
1625 	/*
1626 	 * Copy all the non-end entries from
1627 	 * the index root to the new buffer.
1628 	 */
1629 	to_move = 0;
1630 	e0 = hdr_first_de(hdr);
1631 
1632 	/* Calculate the size to copy. */
1633 	for (e = e0;; e = hdr_next_de(hdr, e)) {
1634 		if (!e) {
1635 			err = -EINVAL;
1636 			goto out_free_root;
1637 		}
1638 
1639 		if (de_is_last(e))
1640 			break;
1641 		to_move += le16_to_cpu(e->size);
1642 	}
1643 
1644 	if (!to_move) {
1645 		re = NULL;
1646 	} else {
1647 		re = kmemdup(e0, to_move, GFP_NOFS);
1648 		if (!re) {
1649 			err = -ENOMEM;
1650 			goto out_free_root;
1651 		}
1652 	}
1653 
1654 	sub_vbn = NULL;
1655 	if (de_has_vcn(e)) {
1656 		t_vbn = de_get_vbn_le(e);
1657 		sub_vbn = &t_vbn;
1658 	}
1659 
1660 	new_root_size = sizeof(struct INDEX_ROOT) + sizeof(struct NTFS_DE) +
1661 			sizeof(u64);
1662 	ds_root = new_root_size - root_size;
1663 
1664 	if (ds_root > 0 && asize + ds_root > sbi->max_bytes_per_attr) {
1665 		/* Make root external. */
1666 		err = -EOPNOTSUPP;
1667 		goto out_free_re;
1668 	}
1669 
1670 	if (ds_root)
1671 		mi_resize_attr(mi, attr, ds_root);
1672 
1673 	/* Fill first entry (vcn will be set later). */
1674 	e = (struct NTFS_DE *)(root + 1);
1675 	memset(e, 0, sizeof(struct NTFS_DE));
1676 	e->size = cpu_to_le16(sizeof(struct NTFS_DE) + sizeof(u64));
1677 	e->flags = NTFS_IE_HAS_SUBNODES | NTFS_IE_LAST;
1678 
1679 	hdr->flags = 1;
1680 	hdr->used = hdr->total =
1681 		cpu_to_le32(new_root_size - offsetof(struct INDEX_ROOT, ihdr));
1682 
1683 	fnd->root_de = hdr_first_de(hdr);
1684 	mi->dirty = true;
1685 
1686 	/* Create alloc and bitmap attributes (if not). */
1687 	err = run_is_empty(&indx->alloc_run) ?
1688 		      indx_create_allocate(indx, ni, &new_vbn) :
1689 		      indx_add_allocate(indx, ni, &new_vbn);
1690 
1691 	/* Layout of record may be changed, so rescan root. */
1692 	root = indx_get_root(indx, ni, &attr, &mi);
1693 	if (!root) {
1694 		/* Bug? */
1695 		ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
1696 		err = -EINVAL;
1697 		goto out_free_re;
1698 	}
1699 
1700 	if (err) {
1701 		/* Restore root. */
1702 		if (mi_resize_attr(mi, attr, -ds_root)) {
1703 			memcpy(attr, a_root, asize);
1704 		} else {
1705 			/* Bug? */
1706 			ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
1707 		}
1708 		goto out_free_re;
1709 	}
1710 
1711 	e = (struct NTFS_DE *)(root + 1);
1712 	*(__le64 *)(e + 1) = cpu_to_le64(new_vbn);
1713 	mi->dirty = true;
1714 
1715 	/* Now we can create/format the new buffer and copy the entries into. */
1716 	n = indx_new(indx, ni, new_vbn, sub_vbn);
1717 	if (IS_ERR(n)) {
1718 		err = PTR_ERR(n);
1719 		goto out_free_re;
1720 	}
1721 
1722 	hdr = &n->index->ihdr;
1723 	hdr_used = le32_to_cpu(hdr->used);
1724 	hdr_total = le32_to_cpu(hdr->total);
1725 
1726 	/* Copy root entries into new buffer. */
1727 	hdr_insert_head(hdr, re, to_move);
1728 
1729 	/* Update bitmap attribute. */
1730 	indx_mark_used(indx, ni, new_vbn >> indx->idx2vbn_bits);
1731 
1732 	/* Check if we can insert new entry new index buffer. */
1733 	if (hdr_used + new_de_size > hdr_total) {
1734 		/*
1735 		 * This occurs if MFT record is the same or bigger than index
1736 		 * buffer. Move all root new index and have no space to add
1737 		 * new entry classic case when MFT record is 1K and index
1738 		 * buffer 4K the problem should not occurs.
1739 		 */
1740 		kfree(re);
1741 		indx_write(indx, ni, n, 0);
1742 
1743 		put_indx_node(n);
1744 		fnd_clear(fnd);
1745 		err = indx_insert_entry(indx, ni, new_de, ctx, fnd, undo);
1746 		goto out_free_root;
1747 	}
1748 
1749 	/*
1750 	 * Now root is a parent for new index buffer.
1751 	 * Insert NewEntry a new buffer.
1752 	 */
1753 	e = hdr_insert_de(indx, hdr, new_de, NULL, ctx);
1754 	if (!e) {
1755 		err = -EINVAL;
1756 		goto out_put_n;
1757 	}
1758 	fnd_push(fnd, n, e);
1759 
1760 	/* Just write updates index into disk. */
1761 	indx_write(indx, ni, n, 0);
1762 
1763 	n = NULL;
1764 
1765 out_put_n:
1766 	put_indx_node(n);
1767 out_free_re:
1768 	kfree(re);
1769 out_free_root:
1770 	kfree(a_root);
1771 	return err;
1772 }
1773 
1774 /*
1775  * indx_insert_into_buffer
1776  *
1777  * Attempt to insert an entry into an Index Allocation Buffer.
1778  * If necessary, it will split the buffer.
1779  */
1780 static int
1781 indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
1782 			struct INDEX_ROOT *root, const struct NTFS_DE *new_de,
1783 			const void *ctx, int level, struct ntfs_fnd *fnd)
1784 {
1785 	int err;
1786 	const struct NTFS_DE *sp;
1787 	struct NTFS_DE *e, *de_t, *up_e;
1788 	struct indx_node *n2;
1789 	struct indx_node *n1 = fnd->nodes[level];
1790 	struct INDEX_HDR *hdr1 = &n1->index->ihdr;
1791 	struct INDEX_HDR *hdr2;
1792 	u32 to_copy, used, used1;
1793 	CLST new_vbn;
1794 	__le64 t_vbn, *sub_vbn;
1795 	u16 sp_size;
1796 	void *hdr1_saved = NULL;
1797 
1798 	/* Try the most easy case. */
1799 	e = fnd->level - 1 == level ? fnd->de[level] : NULL;
1800 	e = hdr_insert_de(indx, hdr1, new_de, e, ctx);
1801 	fnd->de[level] = e;
1802 	if (e) {
1803 		/* Just write updated index into disk. */
1804 		indx_write(indx, ni, n1, 0);
1805 		return 0;
1806 	}
1807 
1808 	/*
1809 	 * No space to insert into buffer. Split it.
1810 	 * To split we:
1811 	 *  - Save split point ('cause index buffers will be changed)
1812 	 * - Allocate NewBuffer and copy all entries <= sp into new buffer
1813 	 * - Remove all entries (sp including) from TargetBuffer
1814 	 * - Insert NewEntry into left or right buffer (depending on sp <=>
1815 	 *     NewEntry)
1816 	 * - Insert sp into parent buffer (or root)
1817 	 * - Make sp a parent for new buffer
1818 	 */
1819 	sp = hdr_find_split(hdr1);
1820 	if (!sp)
1821 		return -EINVAL;
1822 
1823 	sp_size = le16_to_cpu(sp->size);
1824 	up_e = kmalloc(sp_size + sizeof(u64), GFP_NOFS);
1825 	if (!up_e)
1826 		return -ENOMEM;
1827 	memcpy(up_e, sp, sp_size);
1828 
1829 	used1 = le32_to_cpu(hdr1->used);
1830 	hdr1_saved = kmemdup(hdr1, used1, GFP_NOFS);
1831 	if (!hdr1_saved) {
1832 		err = -ENOMEM;
1833 		goto out;
1834 	}
1835 
1836 	if (!hdr1->flags) {
1837 		up_e->flags |= NTFS_IE_HAS_SUBNODES;
1838 		up_e->size = cpu_to_le16(sp_size + sizeof(u64));
1839 		sub_vbn = NULL;
1840 	} else {
1841 		t_vbn = de_get_vbn_le(up_e);
1842 		sub_vbn = &t_vbn;
1843 	}
1844 
1845 	/* Allocate on disk a new index allocation buffer. */
1846 	err = indx_add_allocate(indx, ni, &new_vbn);
1847 	if (err)
1848 		goto out;
1849 
1850 	/* Allocate and format memory a new index buffer. */
1851 	n2 = indx_new(indx, ni, new_vbn, sub_vbn);
1852 	if (IS_ERR(n2)) {
1853 		err = PTR_ERR(n2);
1854 		goto out;
1855 	}
1856 
1857 	hdr2 = &n2->index->ihdr;
1858 
1859 	/* Make sp a parent for new buffer. */
1860 	de_set_vbn(up_e, new_vbn);
1861 
1862 	/* Copy all the entries <= sp into the new buffer. */
1863 	de_t = hdr_first_de(hdr1);
1864 	to_copy = PtrOffset(de_t, sp);
1865 	hdr_insert_head(hdr2, de_t, to_copy);
1866 
1867 	/* Remove all entries (sp including) from hdr1. */
1868 	used = used1 - to_copy - sp_size;
1869 	memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off));
1870 	hdr1->used = cpu_to_le32(used);
1871 
1872 	/*
1873 	 * Insert new entry into left or right buffer
1874 	 * (depending on sp <=> new_de).
1875 	 */
1876 	hdr_insert_de(indx,
1877 		      (*indx->cmp)(new_de + 1, le16_to_cpu(new_de->key_size),
1878 				   up_e + 1, le16_to_cpu(up_e->key_size),
1879 				   ctx) < 0 ?
1880 			      hdr2 :
1881 			      hdr1,
1882 		      new_de, NULL, ctx);
1883 
1884 	indx_mark_used(indx, ni, new_vbn >> indx->idx2vbn_bits);
1885 
1886 	indx_write(indx, ni, n1, 0);
1887 	indx_write(indx, ni, n2, 0);
1888 
1889 	put_indx_node(n2);
1890 
1891 	/*
1892 	 * We've finished splitting everybody, so we are ready to
1893 	 * insert the promoted entry into the parent.
1894 	 */
1895 	if (!level) {
1896 		/* Insert in root. */
1897 		err = indx_insert_into_root(indx, ni, up_e, NULL, ctx, fnd, 0);
1898 	} else {
1899 		/*
1900 		 * The target buffer's parent is another index buffer.
1901 		 * TODO: Remove recursion.
1902 		 */
1903 		err = indx_insert_into_buffer(indx, ni, root, up_e, ctx,
1904 					      level - 1, fnd);
1905 	}
1906 
1907 	if (err) {
1908 		/*
1909 		 * Undo critical operations.
1910 		 */
1911 		indx_mark_free(indx, ni, new_vbn >> indx->idx2vbn_bits);
1912 		memcpy(hdr1, hdr1_saved, used1);
1913 		indx_write(indx, ni, n1, 0);
1914 	}
1915 
1916 out:
1917 	kfree(up_e);
1918 	kfree(hdr1_saved);
1919 
1920 	return err;
1921 }
1922 
1923 /*
1924  * indx_insert_entry - Insert new entry into index.
1925  *
1926  * @undo - True if we undoing previous remove.
1927  */
1928 int indx_insert_entry(struct ntfs_index *indx, struct ntfs_inode *ni,
1929 		      const struct NTFS_DE *new_de, const void *ctx,
1930 		      struct ntfs_fnd *fnd, bool undo)
1931 {
1932 	int err;
1933 	int diff;
1934 	struct NTFS_DE *e;
1935 	struct ntfs_fnd *fnd_a = NULL;
1936 	struct INDEX_ROOT *root;
1937 
1938 	if (!fnd) {
1939 		fnd_a = fnd_get();
1940 		if (!fnd_a) {
1941 			err = -ENOMEM;
1942 			goto out1;
1943 		}
1944 		fnd = fnd_a;
1945 	}
1946 
1947 	root = indx_get_root(indx, ni, NULL, NULL);
1948 	if (!root) {
1949 		err = -EINVAL;
1950 		goto out;
1951 	}
1952 
1953 	if (fnd_is_empty(fnd)) {
1954 		/*
1955 		 * Find the spot the tree where we want to
1956 		 * insert the new entry.
1957 		 */
1958 		err = indx_find(indx, ni, root, new_de + 1,
1959 				le16_to_cpu(new_de->key_size), ctx, &diff, &e,
1960 				fnd);
1961 		if (err)
1962 			goto out;
1963 
1964 		if (!diff) {
1965 			err = -EEXIST;
1966 			goto out;
1967 		}
1968 	}
1969 
1970 	if (!fnd->level) {
1971 		/*
1972 		 * The root is also a leaf, so we'll insert the
1973 		 * new entry into it.
1974 		 */
1975 		err = indx_insert_into_root(indx, ni, new_de, fnd->root_de, ctx,
1976 					    fnd, undo);
1977 	} else {
1978 		/*
1979 		 * Found a leaf buffer, so we'll insert the new entry into it.
1980 		 */
1981 		err = indx_insert_into_buffer(indx, ni, root, new_de, ctx,
1982 					      fnd->level - 1, fnd);
1983 	}
1984 
1985 out:
1986 	fnd_put(fnd_a);
1987 out1:
1988 	return err;
1989 }
1990 
1991 /*
1992  * indx_find_buffer - Locate a buffer from the tree.
1993  */
1994 static struct indx_node *indx_find_buffer(struct ntfs_index *indx,
1995 					  struct ntfs_inode *ni,
1996 					  const struct INDEX_ROOT *root,
1997 					  __le64 vbn, struct indx_node *n)
1998 {
1999 	int err;
2000 	const struct NTFS_DE *e;
2001 	struct indx_node *r;
2002 	const struct INDEX_HDR *hdr = n ? &n->index->ihdr : &root->ihdr;
2003 
2004 	/* Step 1: Scan one level. */
2005 	for (e = hdr_first_de(hdr);; e = hdr_next_de(hdr, e)) {
2006 		if (!e)
2007 			return ERR_PTR(-EINVAL);
2008 
2009 		if (de_has_vcn(e) && vbn == de_get_vbn_le(e))
2010 			return n;
2011 
2012 		if (de_is_last(e))
2013 			break;
2014 	}
2015 
2016 	/* Step2: Do recursion. */
2017 	e = Add2Ptr(hdr, le32_to_cpu(hdr->de_off));
2018 	for (;;) {
2019 		if (de_has_vcn_ex(e)) {
2020 			err = indx_read(indx, ni, de_get_vbn(e), &n);
2021 			if (err)
2022 				return ERR_PTR(err);
2023 
2024 			r = indx_find_buffer(indx, ni, root, vbn, n);
2025 			if (r)
2026 				return r;
2027 		}
2028 
2029 		if (de_is_last(e))
2030 			break;
2031 
2032 		e = Add2Ptr(e, le16_to_cpu(e->size));
2033 	}
2034 
2035 	return NULL;
2036 }
2037 
2038 /*
2039  * indx_shrink - Deallocate unused tail indexes.
2040  */
2041 static int indx_shrink(struct ntfs_index *indx, struct ntfs_inode *ni,
2042 		       size_t bit)
2043 {
2044 	int err = 0;
2045 	u64 bpb, new_data;
2046 	size_t nbits;
2047 	struct ATTRIB *b;
2048 	struct ATTR_LIST_ENTRY *le = NULL;
2049 	const struct INDEX_NAMES *in = &s_index_names[indx->type];
2050 
2051 	b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
2052 			 NULL, NULL);
2053 
2054 	if (!b)
2055 		return -ENOENT;
2056 
2057 	if (!b->non_res) {
2058 		unsigned long pos;
2059 		const unsigned long *bm = resident_data(b);
2060 
2061 		nbits = (size_t)le32_to_cpu(b->res.data_size) * 8;
2062 
2063 		if (bit >= nbits)
2064 			return 0;
2065 
2066 		pos = find_next_bit_le(bm, nbits, bit);
2067 		if (pos < nbits)
2068 			return 0;
2069 	} else {
2070 		size_t used = MINUS_ONE_T;
2071 
2072 		nbits = le64_to_cpu(b->nres.data_size) * 8;
2073 
2074 		if (bit >= nbits)
2075 			return 0;
2076 
2077 		err = scan_nres_bitmap(ni, b, indx, bit, &scan_for_used, &used);
2078 		if (err)
2079 			return err;
2080 
2081 		if (used != MINUS_ONE_T)
2082 			return 0;
2083 	}
2084 
2085 	new_data = (u64)bit << indx->index_bits;
2086 
2087 	err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
2088 			    &indx->alloc_run, new_data, &new_data, false, NULL);
2089 	if (err)
2090 		return err;
2091 
2092 	if (in->name == I30_NAME)
2093 		i_size_write(&ni->vfs_inode, new_data);
2094 
2095 	bpb = bitmap_size(bit);
2096 	if (bpb * 8 == nbits)
2097 		return 0;
2098 
2099 	err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
2100 			    &indx->bitmap_run, bpb, &bpb, false, NULL);
2101 
2102 	return err;
2103 }
2104 
2105 static int indx_free_children(struct ntfs_index *indx, struct ntfs_inode *ni,
2106 			      const struct NTFS_DE *e, bool trim)
2107 {
2108 	int err;
2109 	struct indx_node *n = NULL;
2110 	struct INDEX_HDR *hdr;
2111 	CLST vbn = de_get_vbn(e);
2112 	size_t i;
2113 
2114 	err = indx_read(indx, ni, vbn, &n);
2115 	if (err)
2116 		return err;
2117 
2118 	hdr = &n->index->ihdr;
2119 	/* First, recurse into the children, if any. */
2120 	if (hdr_has_subnode(hdr)) {
2121 		for (e = hdr_first_de(hdr); e; e = hdr_next_de(hdr, e)) {
2122 			indx_free_children(indx, ni, e, false);
2123 			if (de_is_last(e))
2124 				break;
2125 		}
2126 	}
2127 
2128 	put_indx_node(n);
2129 
2130 	i = vbn >> indx->idx2vbn_bits;
2131 	/*
2132 	 * We've gotten rid of the children; add this buffer to the free list.
2133 	 */
2134 	indx_mark_free(indx, ni, i);
2135 
2136 	if (!trim)
2137 		return 0;
2138 
2139 	/*
2140 	 * If there are no used indexes after current free index
2141 	 * then we can truncate allocation and bitmap.
2142 	 * Use bitmap to estimate the case.
2143 	 */
2144 	indx_shrink(indx, ni, i + 1);
2145 	return 0;
2146 }
2147 
2148 /*
2149  * indx_get_entry_to_replace
2150  *
2151  * Find a replacement entry for a deleted entry.
2152  * Always returns a node entry:
2153  * NTFS_IE_HAS_SUBNODES is set the flags and the size includes the sub_vcn.
2154  */
2155 static int indx_get_entry_to_replace(struct ntfs_index *indx,
2156 				     struct ntfs_inode *ni,
2157 				     const struct NTFS_DE *de_next,
2158 				     struct NTFS_DE **de_to_replace,
2159 				     struct ntfs_fnd *fnd)
2160 {
2161 	int err;
2162 	int level = -1;
2163 	CLST vbn;
2164 	struct NTFS_DE *e, *te, *re;
2165 	struct indx_node *n;
2166 	struct INDEX_BUFFER *ib;
2167 
2168 	*de_to_replace = NULL;
2169 
2170 	/* Find first leaf entry down from de_next. */
2171 	vbn = de_get_vbn(de_next);
2172 	for (;;) {
2173 		n = NULL;
2174 		err = indx_read(indx, ni, vbn, &n);
2175 		if (err)
2176 			goto out;
2177 
2178 		e = hdr_first_de(&n->index->ihdr);
2179 		fnd_push(fnd, n, e);
2180 
2181 		if (!de_is_last(e)) {
2182 			/*
2183 			 * This buffer is non-empty, so its first entry
2184 			 * could be used as the replacement entry.
2185 			 */
2186 			level = fnd->level - 1;
2187 		}
2188 
2189 		if (!de_has_vcn(e))
2190 			break;
2191 
2192 		/* This buffer is a node. Continue to go down. */
2193 		vbn = de_get_vbn(e);
2194 	}
2195 
2196 	if (level == -1)
2197 		goto out;
2198 
2199 	n = fnd->nodes[level];
2200 	te = hdr_first_de(&n->index->ihdr);
2201 	/* Copy the candidate entry into the replacement entry buffer. */
2202 	re = kmalloc(le16_to_cpu(te->size) + sizeof(u64), GFP_NOFS);
2203 	if (!re) {
2204 		err = -ENOMEM;
2205 		goto out;
2206 	}
2207 
2208 	*de_to_replace = re;
2209 	memcpy(re, te, le16_to_cpu(te->size));
2210 
2211 	if (!de_has_vcn(re)) {
2212 		/*
2213 		 * The replacement entry we found doesn't have a sub_vcn.
2214 		 * increase its size to hold one.
2215 		 */
2216 		le16_add_cpu(&re->size, sizeof(u64));
2217 		re->flags |= NTFS_IE_HAS_SUBNODES;
2218 	} else {
2219 		/*
2220 		 * The replacement entry we found was a node entry, which
2221 		 * means that all its child buffers are empty. Return them
2222 		 * to the free pool.
2223 		 */
2224 		indx_free_children(indx, ni, te, true);
2225 	}
2226 
2227 	/*
2228 	 * Expunge the replacement entry from its former location,
2229 	 * and then write that buffer.
2230 	 */
2231 	ib = n->index;
2232 	e = hdr_delete_de(&ib->ihdr, te);
2233 
2234 	fnd->de[level] = e;
2235 	indx_write(indx, ni, n, 0);
2236 
2237 	if (ib_is_leaf(ib) && ib_is_empty(ib)) {
2238 		/* An empty leaf. */
2239 		return 0;
2240 	}
2241 
2242 out:
2243 	fnd_clear(fnd);
2244 	return err;
2245 }
2246 
2247 /*
2248  * indx_delete_entry - Delete an entry from the index.
2249  */
2250 int indx_delete_entry(struct ntfs_index *indx, struct ntfs_inode *ni,
2251 		      const void *key, u32 key_len, const void *ctx)
2252 {
2253 	int err, diff;
2254 	struct INDEX_ROOT *root;
2255 	struct INDEX_HDR *hdr;
2256 	struct ntfs_fnd *fnd, *fnd2;
2257 	struct INDEX_BUFFER *ib;
2258 	struct NTFS_DE *e, *re, *next, *prev, *me;
2259 	struct indx_node *n, *n2d = NULL;
2260 	__le64 sub_vbn;
2261 	int level, level2;
2262 	struct ATTRIB *attr;
2263 	struct mft_inode *mi;
2264 	u32 e_size, root_size, new_root_size;
2265 	size_t trim_bit;
2266 	const struct INDEX_NAMES *in;
2267 
2268 	fnd = fnd_get();
2269 	if (!fnd) {
2270 		err = -ENOMEM;
2271 		goto out2;
2272 	}
2273 
2274 	fnd2 = fnd_get();
2275 	if (!fnd2) {
2276 		err = -ENOMEM;
2277 		goto out1;
2278 	}
2279 
2280 	root = indx_get_root(indx, ni, &attr, &mi);
2281 	if (!root) {
2282 		err = -EINVAL;
2283 		goto out;
2284 	}
2285 
2286 	/* Locate the entry to remove. */
2287 	err = indx_find(indx, ni, root, key, key_len, ctx, &diff, &e, fnd);
2288 	if (err)
2289 		goto out;
2290 
2291 	if (!e || diff) {
2292 		err = -ENOENT;
2293 		goto out;
2294 	}
2295 
2296 	level = fnd->level;
2297 
2298 	if (level) {
2299 		n = fnd->nodes[level - 1];
2300 		e = fnd->de[level - 1];
2301 		ib = n->index;
2302 		hdr = &ib->ihdr;
2303 	} else {
2304 		hdr = &root->ihdr;
2305 		e = fnd->root_de;
2306 		n = NULL;
2307 	}
2308 
2309 	e_size = le16_to_cpu(e->size);
2310 
2311 	if (!de_has_vcn_ex(e)) {
2312 		/* The entry to delete is a leaf, so we can just rip it out. */
2313 		hdr_delete_de(hdr, e);
2314 
2315 		if (!level) {
2316 			hdr->total = hdr->used;
2317 
2318 			/* Shrink resident root attribute. */
2319 			mi_resize_attr(mi, attr, 0 - e_size);
2320 			goto out;
2321 		}
2322 
2323 		indx_write(indx, ni, n, 0);
2324 
2325 		/*
2326 		 * Check to see if removing that entry made
2327 		 * the leaf empty.
2328 		 */
2329 		if (ib_is_leaf(ib) && ib_is_empty(ib)) {
2330 			fnd_pop(fnd);
2331 			fnd_push(fnd2, n, e);
2332 		}
2333 	} else {
2334 		/*
2335 		 * The entry we wish to delete is a node buffer, so we
2336 		 * have to find a replacement for it.
2337 		 */
2338 		next = de_get_next(e);
2339 
2340 		err = indx_get_entry_to_replace(indx, ni, next, &re, fnd2);
2341 		if (err)
2342 			goto out;
2343 
2344 		if (re) {
2345 			de_set_vbn_le(re, de_get_vbn_le(e));
2346 			hdr_delete_de(hdr, e);
2347 
2348 			err = level ? indx_insert_into_buffer(indx, ni, root,
2349 							      re, ctx,
2350 							      fnd->level - 1,
2351 							      fnd) :
2352 				      indx_insert_into_root(indx, ni, re, e,
2353 							    ctx, fnd, 0);
2354 			kfree(re);
2355 
2356 			if (err)
2357 				goto out;
2358 		} else {
2359 			/*
2360 			 * There is no replacement for the current entry.
2361 			 * This means that the subtree rooted at its node
2362 			 * is empty, and can be deleted, which turn means
2363 			 * that the node can just inherit the deleted
2364 			 * entry sub_vcn.
2365 			 */
2366 			indx_free_children(indx, ni, next, true);
2367 
2368 			de_set_vbn_le(next, de_get_vbn_le(e));
2369 			hdr_delete_de(hdr, e);
2370 			if (level) {
2371 				indx_write(indx, ni, n, 0);
2372 			} else {
2373 				hdr->total = hdr->used;
2374 
2375 				/* Shrink resident root attribute. */
2376 				mi_resize_attr(mi, attr, 0 - e_size);
2377 			}
2378 		}
2379 	}
2380 
2381 	/* Delete a branch of tree. */
2382 	if (!fnd2 || !fnd2->level)
2383 		goto out;
2384 
2385 	/* Reinit root 'cause it can be changed. */
2386 	root = indx_get_root(indx, ni, &attr, &mi);
2387 	if (!root) {
2388 		err = -EINVAL;
2389 		goto out;
2390 	}
2391 
2392 	n2d = NULL;
2393 	sub_vbn = fnd2->nodes[0]->index->vbn;
2394 	level2 = 0;
2395 	level = fnd->level;
2396 
2397 	hdr = level ? &fnd->nodes[level - 1]->index->ihdr : &root->ihdr;
2398 
2399 	/* Scan current level. */
2400 	for (e = hdr_first_de(hdr);; e = hdr_next_de(hdr, e)) {
2401 		if (!e) {
2402 			err = -EINVAL;
2403 			goto out;
2404 		}
2405 
2406 		if (de_has_vcn(e) && sub_vbn == de_get_vbn_le(e))
2407 			break;
2408 
2409 		if (de_is_last(e)) {
2410 			e = NULL;
2411 			break;
2412 		}
2413 	}
2414 
2415 	if (!e) {
2416 		/* Do slow search from root. */
2417 		struct indx_node *in;
2418 
2419 		fnd_clear(fnd);
2420 
2421 		in = indx_find_buffer(indx, ni, root, sub_vbn, NULL);
2422 		if (IS_ERR(in)) {
2423 			err = PTR_ERR(in);
2424 			goto out;
2425 		}
2426 
2427 		if (in)
2428 			fnd_push(fnd, in, NULL);
2429 	}
2430 
2431 	/* Merge fnd2 -> fnd. */
2432 	for (level = 0; level < fnd2->level; level++) {
2433 		fnd_push(fnd, fnd2->nodes[level], fnd2->de[level]);
2434 		fnd2->nodes[level] = NULL;
2435 	}
2436 	fnd2->level = 0;
2437 
2438 	hdr = NULL;
2439 	for (level = fnd->level; level; level--) {
2440 		struct indx_node *in = fnd->nodes[level - 1];
2441 
2442 		ib = in->index;
2443 		if (ib_is_empty(ib)) {
2444 			sub_vbn = ib->vbn;
2445 		} else {
2446 			hdr = &ib->ihdr;
2447 			n2d = in;
2448 			level2 = level;
2449 			break;
2450 		}
2451 	}
2452 
2453 	if (!hdr)
2454 		hdr = &root->ihdr;
2455 
2456 	e = hdr_first_de(hdr);
2457 	if (!e) {
2458 		err = -EINVAL;
2459 		goto out;
2460 	}
2461 
2462 	if (hdr != &root->ihdr || !de_is_last(e)) {
2463 		prev = NULL;
2464 		while (!de_is_last(e)) {
2465 			if (de_has_vcn(e) && sub_vbn == de_get_vbn_le(e))
2466 				break;
2467 			prev = e;
2468 			e = hdr_next_de(hdr, e);
2469 			if (!e) {
2470 				err = -EINVAL;
2471 				goto out;
2472 			}
2473 		}
2474 
2475 		if (sub_vbn != de_get_vbn_le(e)) {
2476 			/*
2477 			 * Didn't find the parent entry, although this buffer
2478 			 * is the parent trail. Something is corrupt.
2479 			 */
2480 			err = -EINVAL;
2481 			goto out;
2482 		}
2483 
2484 		if (de_is_last(e)) {
2485 			/*
2486 			 * Since we can't remove the end entry, we'll remove
2487 			 * its predecessor instead. This means we have to
2488 			 * transfer the predecessor's sub_vcn to the end entry.
2489 			 * Note: This index block is not empty, so the
2490 			 * predecessor must exist.
2491 			 */
2492 			if (!prev) {
2493 				err = -EINVAL;
2494 				goto out;
2495 			}
2496 
2497 			if (de_has_vcn(prev)) {
2498 				de_set_vbn_le(e, de_get_vbn_le(prev));
2499 			} else if (de_has_vcn(e)) {
2500 				le16_sub_cpu(&e->size, sizeof(u64));
2501 				e->flags &= ~NTFS_IE_HAS_SUBNODES;
2502 				le32_sub_cpu(&hdr->used, sizeof(u64));
2503 			}
2504 			e = prev;
2505 		}
2506 
2507 		/*
2508 		 * Copy the current entry into a temporary buffer (stripping
2509 		 * off its down-pointer, if any) and delete it from the current
2510 		 * buffer or root, as appropriate.
2511 		 */
2512 		e_size = le16_to_cpu(e->size);
2513 		me = kmemdup(e, e_size, GFP_NOFS);
2514 		if (!me) {
2515 			err = -ENOMEM;
2516 			goto out;
2517 		}
2518 
2519 		if (de_has_vcn(me)) {
2520 			me->flags &= ~NTFS_IE_HAS_SUBNODES;
2521 			le16_sub_cpu(&me->size, sizeof(u64));
2522 		}
2523 
2524 		hdr_delete_de(hdr, e);
2525 
2526 		if (hdr == &root->ihdr) {
2527 			level = 0;
2528 			hdr->total = hdr->used;
2529 
2530 			/* Shrink resident root attribute. */
2531 			mi_resize_attr(mi, attr, 0 - e_size);
2532 		} else {
2533 			indx_write(indx, ni, n2d, 0);
2534 			level = level2;
2535 		}
2536 
2537 		/* Mark unused buffers as free. */
2538 		trim_bit = -1;
2539 		for (; level < fnd->level; level++) {
2540 			ib = fnd->nodes[level]->index;
2541 			if (ib_is_empty(ib)) {
2542 				size_t k = le64_to_cpu(ib->vbn) >>
2543 					   indx->idx2vbn_bits;
2544 
2545 				indx_mark_free(indx, ni, k);
2546 				if (k < trim_bit)
2547 					trim_bit = k;
2548 			}
2549 		}
2550 
2551 		fnd_clear(fnd);
2552 		/*fnd->root_de = NULL;*/
2553 
2554 		/*
2555 		 * Re-insert the entry into the tree.
2556 		 * Find the spot the tree where we want to insert the new entry.
2557 		 */
2558 		err = indx_insert_entry(indx, ni, me, ctx, fnd, 0);
2559 		kfree(me);
2560 		if (err)
2561 			goto out;
2562 
2563 		if (trim_bit != -1)
2564 			indx_shrink(indx, ni, trim_bit);
2565 	} else {
2566 		/*
2567 		 * This tree needs to be collapsed down to an empty root.
2568 		 * Recreate the index root as an empty leaf and free all
2569 		 * the bits the index allocation bitmap.
2570 		 */
2571 		fnd_clear(fnd);
2572 		fnd_clear(fnd2);
2573 
2574 		in = &s_index_names[indx->type];
2575 
2576 		err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
2577 				    &indx->alloc_run, 0, NULL, false, NULL);
2578 		if (in->name == I30_NAME)
2579 			i_size_write(&ni->vfs_inode, 0);
2580 
2581 		err = ni_remove_attr(ni, ATTR_ALLOC, in->name, in->name_len,
2582 				     false, NULL);
2583 		run_close(&indx->alloc_run);
2584 
2585 		err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
2586 				    &indx->bitmap_run, 0, NULL, false, NULL);
2587 		err = ni_remove_attr(ni, ATTR_BITMAP, in->name, in->name_len,
2588 				     false, NULL);
2589 		run_close(&indx->bitmap_run);
2590 
2591 		root = indx_get_root(indx, ni, &attr, &mi);
2592 		if (!root) {
2593 			err = -EINVAL;
2594 			goto out;
2595 		}
2596 
2597 		root_size = le32_to_cpu(attr->res.data_size);
2598 		new_root_size =
2599 			sizeof(struct INDEX_ROOT) + sizeof(struct NTFS_DE);
2600 
2601 		if (new_root_size != root_size &&
2602 		    !mi_resize_attr(mi, attr, new_root_size - root_size)) {
2603 			err = -EINVAL;
2604 			goto out;
2605 		}
2606 
2607 		/* Fill first entry. */
2608 		e = (struct NTFS_DE *)(root + 1);
2609 		e->ref.low = 0;
2610 		e->ref.high = 0;
2611 		e->ref.seq = 0;
2612 		e->size = cpu_to_le16(sizeof(struct NTFS_DE));
2613 		e->flags = NTFS_IE_LAST; // 0x02
2614 		e->key_size = 0;
2615 		e->res = 0;
2616 
2617 		hdr = &root->ihdr;
2618 		hdr->flags = 0;
2619 		hdr->used = hdr->total = cpu_to_le32(
2620 			new_root_size - offsetof(struct INDEX_ROOT, ihdr));
2621 		mi->dirty = true;
2622 	}
2623 
2624 out:
2625 	fnd_put(fnd2);
2626 out1:
2627 	fnd_put(fnd);
2628 out2:
2629 	return err;
2630 }
2631 
2632 /*
2633  * Update duplicated information in directory entry
2634  * 'dup' - info from MFT record
2635  */
2636 int indx_update_dup(struct ntfs_inode *ni, struct ntfs_sb_info *sbi,
2637 		    const struct ATTR_FILE_NAME *fname,
2638 		    const struct NTFS_DUP_INFO *dup, int sync)
2639 {
2640 	int err, diff;
2641 	struct NTFS_DE *e = NULL;
2642 	struct ATTR_FILE_NAME *e_fname;
2643 	struct ntfs_fnd *fnd;
2644 	struct INDEX_ROOT *root;
2645 	struct mft_inode *mi;
2646 	struct ntfs_index *indx = &ni->dir;
2647 
2648 	fnd = fnd_get();
2649 	if (!fnd)
2650 		return -ENOMEM;
2651 
2652 	root = indx_get_root(indx, ni, NULL, &mi);
2653 	if (!root) {
2654 		err = -EINVAL;
2655 		goto out;
2656 	}
2657 
2658 	/* Find entry in directory. */
2659 	err = indx_find(indx, ni, root, fname, fname_full_size(fname), sbi,
2660 			&diff, &e, fnd);
2661 	if (err)
2662 		goto out;
2663 
2664 	if (!e) {
2665 		err = -EINVAL;
2666 		goto out;
2667 	}
2668 
2669 	if (diff) {
2670 		err = -EINVAL;
2671 		goto out;
2672 	}
2673 
2674 	e_fname = (struct ATTR_FILE_NAME *)(e + 1);
2675 
2676 	if (!memcmp(&e_fname->dup, dup, sizeof(*dup))) {
2677 		/*
2678 		 * Nothing to update in index! Try to avoid this call.
2679 		 */
2680 		goto out;
2681 	}
2682 
2683 	memcpy(&e_fname->dup, dup, sizeof(*dup));
2684 
2685 	if (fnd->level) {
2686 		/* Directory entry in index. */
2687 		err = indx_write(indx, ni, fnd->nodes[fnd->level - 1], sync);
2688 	} else {
2689 		/* Directory entry in directory MFT record. */
2690 		mi->dirty = true;
2691 		if (sync)
2692 			err = mi_write(mi, 1);
2693 		else
2694 			mark_inode_dirty(&ni->vfs_inode);
2695 	}
2696 
2697 out:
2698 	fnd_put(fnd);
2699 	return err;
2700 }
2701