fs/ntfs3/index.c

   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 = NTFS_INDEX_HDR_HAS_SUBNODES;
 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, ntfs3_bitmap_size(1), ATTR_BITMAP,
1460                                  in->name, 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,
1522                                     ntfs3_bitmap_size(bit + 1), NULL, true,
1523                                     NULL);
1524                 if (err)
1525                         goto out1;
1526         }
1527
1528         alloc = ni_find_attr(ni, NULL, NULL, ATTR_ALLOC, in->name, in->name_len,
1529                              NULL, &mi);
1530         if (!alloc) {
1531                 err = -EINVAL;
1532                 if (bmp)
1533                         goto out2;
1534                 goto out1;
1535         }
1536
1537         if (data_size <= le64_to_cpu(alloc->nres.data_size)) {
1538                 /* Reuse index. */
1539                 goto out;
1540         }
1541
1542         /* Increase allocation. */
1543         err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
1544                             &indx->alloc_run, data_size, &data_size, true,
1545                             NULL);
1546         if (err) {
1547                 if (bmp)
1548                         goto out2;
1549                 goto out1;
1550         }
1551
1552         if (in->name == I30_NAME)
1553                 i_size_write(&ni->vfs_inode, data_size);
1554
1555 out:
1556         *vbn = bit << indx->idx2vbn_bits;
1557
1558         return 0;
1559
1560 out2:
1561         /* Ops. No space? */
1562         attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
1563                       &indx->bitmap_run, bmp_size, &bmp_size_v, false, NULL);
1564
1565 out1:
1566         return err;
1567 }
1568
1569 /*
1570  * indx_insert_into_root - Attempt to insert an entry into the index root.
1571  *
1572  * @undo - True if we undoing previous remove.
1573  * If necessary, it will twiddle the index b-tree.
1574  */
1575 static int indx_insert_into_root(struct ntfs_index *indx, struct ntfs_inode *ni,
1576                                  const struct NTFS_DE *new_de,
1577                                  struct NTFS_DE *root_de, const void *ctx,
1578                                  struct ntfs_fnd *fnd, bool undo)
1579 {
1580         int err = 0;
1581         struct NTFS_DE *e, *e0, *re;
1582         struct mft_inode *mi;
1583         struct ATTRIB *attr;
1584         struct INDEX_HDR *hdr;
1585         struct indx_node *n;
1586         CLST new_vbn;
1587         __le64 *sub_vbn, t_vbn;
1588         u16 new_de_size;
1589         u32 hdr_used, hdr_total, asize, to_move;
1590         u32 root_size, new_root_size;
1591         struct ntfs_sb_info *sbi;
1592         int ds_root;
1593         struct INDEX_ROOT *root, *a_root;
1594
1595         /* Get the record this root placed in. */
1596         root = indx_get_root(indx, ni, &attr, &mi);
1597         if (!root)
1598                 return -EINVAL;
1599
1600         /*
1601          * Try easy case:
1602          * hdr_insert_de will succeed if there's
1603          * room the root for the new entry.
1604          */
1605         hdr = &root->ihdr;
1606         sbi = ni->mi.sbi;
1607         new_de_size = le16_to_cpu(new_de->size);
1608         hdr_used = le32_to_cpu(hdr->used);
1609         hdr_total = le32_to_cpu(hdr->total);
1610         asize = le32_to_cpu(attr->size);
1611         root_size = le32_to_cpu(attr->res.data_size);
1612
1613         ds_root = new_de_size + hdr_used - hdr_total;
1614
1615         /* If 'undo' is set then reduce requirements. */
1616         if ((undo || asize + ds_root < sbi->max_bytes_per_attr) &&
1617             mi_resize_attr(mi, attr, ds_root)) {
1618                 hdr->total = cpu_to_le32(hdr_total + ds_root);
1619                 e = hdr_insert_de(indx, hdr, new_de, root_de, ctx);
1620                 WARN_ON(!e);
1621                 fnd_clear(fnd);
1622                 fnd->root_de = e;
1623
1624                 return 0;
1625         }
1626
1627         /* Make a copy of root attribute to restore if error. */
1628         a_root = kmemdup(attr, asize, GFP_NOFS);
1629         if (!a_root)
1630                 return -ENOMEM;
1631
1632         /*
1633          * Copy all the non-end entries from
1634          * the index root to the new buffer.
1635          */
1636         to_move = 0;
1637         e0 = hdr_first_de(hdr);
1638
1639         /* Calculate the size to copy. */
1640         for (e = e0;; e = hdr_next_de(hdr, e)) {
1641                 if (!e) {
1642                         err = -EINVAL;
1643                         goto out_free_root;
1644                 }
1645
1646                 if (de_is_last(e))
1647                         break;
1648                 to_move += le16_to_cpu(e->size);
1649         }
1650
1651         if (!to_move) {
1652                 re = NULL;
1653         } else {
1654                 re = kmemdup(e0, to_move, GFP_NOFS);
1655                 if (!re) {
1656                         err = -ENOMEM;
1657                         goto out_free_root;
1658                 }
1659         }
1660
1661         sub_vbn = NULL;
1662         if (de_has_vcn(e)) {
1663                 t_vbn = de_get_vbn_le(e);
1664                 sub_vbn = &t_vbn;
1665         }
1666
1667         new_root_size = sizeof(struct INDEX_ROOT) + sizeof(struct NTFS_DE) +
1668                         sizeof(u64);
1669         ds_root = new_root_size - root_size;
1670
1671         if (ds_root > 0 && asize + ds_root > sbi->max_bytes_per_attr) {
1672                 /* Make root external. */
1673                 err = -EOPNOTSUPP;
1674                 goto out_free_re;
1675         }
1676
1677         if (ds_root)
1678                 mi_resize_attr(mi, attr, ds_root);
1679
1680         /* Fill first entry (vcn will be set later). */
1681         e = (struct NTFS_DE *)(root + 1);
1682         memset(e, 0, sizeof(struct NTFS_DE));
1683         e->size = cpu_to_le16(sizeof(struct NTFS_DE) + sizeof(u64));
1684         e->flags = NTFS_IE_HAS_SUBNODES | NTFS_IE_LAST;
1685
1686         hdr->flags = NTFS_INDEX_HDR_HAS_SUBNODES;
1687         hdr->used = hdr->total =
1688                 cpu_to_le32(new_root_size - offsetof(struct INDEX_ROOT, ihdr));
1689
1690         fnd->root_de = hdr_first_de(hdr);
1691         mi->dirty = true;
1692
1693         /* Create alloc and bitmap attributes (if not). */
1694         err = run_is_empty(&indx->alloc_run) ?
1695                       indx_create_allocate(indx, ni, &new_vbn) :
1696                       indx_add_allocate(indx, ni, &new_vbn);
1697
1698         /* Layout of record may be changed, so rescan root. */
1699         root = indx_get_root(indx, ni, &attr, &mi);
1700         if (!root) {
1701                 /* Bug? */
1702                 ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
1703                 err = -EINVAL;
1704                 goto out_free_re;
1705         }
1706
1707         if (err) {
1708                 /* Restore root. */
1709                 if (mi_resize_attr(mi, attr, -ds_root)) {
1710                         memcpy(attr, a_root, asize);
1711                 } else {
1712                         /* Bug? */
1713                         ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
1714                 }
1715                 goto out_free_re;
1716         }
1717
1718         e = (struct NTFS_DE *)(root + 1);
1719         *(__le64 *)(e + 1) = cpu_to_le64(new_vbn);
1720         mi->dirty = true;
1721
1722         /* Now we can create/format the new buffer and copy the entries into. */
1723         n = indx_new(indx, ni, new_vbn, sub_vbn);
1724         if (IS_ERR(n)) {
1725                 err = PTR_ERR(n);
1726                 goto out_free_re;
1727         }
1728
1729         hdr = &n->index->ihdr;
1730         hdr_used = le32_to_cpu(hdr->used);
1731         hdr_total = le32_to_cpu(hdr->total);
1732
1733         /* Copy root entries into new buffer. */
1734         hdr_insert_head(hdr, re, to_move);
1735
1736         /* Update bitmap attribute. */
1737         indx_mark_used(indx, ni, new_vbn >> indx->idx2vbn_bits);
1738
1739         /* Check if we can insert new entry new index buffer. */
1740         if (hdr_used + new_de_size > hdr_total) {
1741                 /*
1742                  * This occurs if MFT record is the same or bigger than index
1743                  * buffer. Move all root new index and have no space to add
1744                  * new entry classic case when MFT record is 1K and index
1745                  * buffer 4K the problem should not occurs.
1746                  */
1747                 kfree(re);
1748                 indx_write(indx, ni, n, 0);
1749
1750                 put_indx_node(n);
1751                 fnd_clear(fnd);
1752                 err = indx_insert_entry(indx, ni, new_de, ctx, fnd, undo);
1753                 goto out_free_root;
1754         }
1755
1756         /*
1757          * Now root is a parent for new index buffer.
1758          * Insert NewEntry a new buffer.
1759          */
1760         e = hdr_insert_de(indx, hdr, new_de, NULL, ctx);
1761         if (!e) {
1762                 err = -EINVAL;
1763                 goto out_put_n;
1764         }
1765         fnd_push(fnd, n, e);
1766
1767         /* Just write updates index into disk. */
1768         indx_write(indx, ni, n, 0);
1769
1770         n = NULL;
1771
1772 out_put_n:
1773         put_indx_node(n);
1774 out_free_re:
1775         kfree(re);
1776 out_free_root:
1777         kfree(a_root);
1778         return err;
1779 }
1780
1781 /*
1782  * indx_insert_into_buffer
1783  *
1784  * Attempt to insert an entry into an Index Allocation Buffer.
1785  * If necessary, it will split the buffer.
1786  */
1787 static int
1788 indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni,
1789                         struct INDEX_ROOT *root, const struct NTFS_DE *new_de,
1790                         const void *ctx, int level, struct ntfs_fnd *fnd)
1791 {
1792         int err;
1793         const struct NTFS_DE *sp;
1794         struct NTFS_DE *e, *de_t, *up_e;
1795         struct indx_node *n2;
1796         struct indx_node *n1 = fnd->nodes[level];
1797         struct INDEX_HDR *hdr1 = &n1->index->ihdr;
1798         struct INDEX_HDR *hdr2;
1799         u32 to_copy, used, used1;
1800         CLST new_vbn;
1801         __le64 t_vbn, *sub_vbn;
1802         u16 sp_size;
1803         void *hdr1_saved = NULL;
1804
1805         /* Try the most easy case. */
1806         e = fnd->level - 1 == level ? fnd->de[level] : NULL;
1807         e = hdr_insert_de(indx, hdr1, new_de, e, ctx);
1808         fnd->de[level] = e;
1809         if (e) {
1810                 /* Just write updated index into disk. */
1811                 indx_write(indx, ni, n1, 0);
1812                 return 0;
1813         }
1814
1815         /*
1816          * No space to insert into buffer. Split it.
1817          * To split we:
1818          *  - Save split point ('cause index buffers will be changed)
1819          * - Allocate NewBuffer and copy all entries <= sp into new buffer
1820          * - Remove all entries (sp including) from TargetBuffer
1821          * - Insert NewEntry into left or right buffer (depending on sp <=>
1822          *     NewEntry)
1823          * - Insert sp into parent buffer (or root)
1824          * - Make sp a parent for new buffer
1825          */
1826         sp = hdr_find_split(hdr1);
1827         if (!sp)
1828                 return -EINVAL;
1829
1830         sp_size = le16_to_cpu(sp->size);
1831         up_e = kmalloc(sp_size + sizeof(u64), GFP_NOFS);
1832         if (!up_e)
1833                 return -ENOMEM;
1834         memcpy(up_e, sp, sp_size);
1835
1836         used1 = le32_to_cpu(hdr1->used);
1837         hdr1_saved = kmemdup(hdr1, used1, GFP_NOFS);
1838         if (!hdr1_saved) {
1839                 err = -ENOMEM;
1840                 goto out;
1841         }
1842
1843         if (!hdr1->flags) {
1844                 up_e->flags |= NTFS_IE_HAS_SUBNODES;
1845                 up_e->size = cpu_to_le16(sp_size + sizeof(u64));
1846                 sub_vbn = NULL;
1847         } else {
1848                 t_vbn = de_get_vbn_le(up_e);
1849                 sub_vbn = &t_vbn;
1850         }
1851
1852         /* Allocate on disk a new index allocation buffer. */
1853         err = indx_add_allocate(indx, ni, &new_vbn);
1854         if (err)
1855                 goto out;
1856
1857         /* Allocate and format memory a new index buffer. */
1858         n2 = indx_new(indx, ni, new_vbn, sub_vbn);
1859         if (IS_ERR(n2)) {
1860                 err = PTR_ERR(n2);
1861                 goto out;
1862         }
1863
1864         hdr2 = &n2->index->ihdr;
1865
1866         /* Make sp a parent for new buffer. */
1867         de_set_vbn(up_e, new_vbn);
1868
1869         /* Copy all the entries <= sp into the new buffer. */
1870         de_t = hdr_first_de(hdr1);
1871         to_copy = PtrOffset(de_t, sp);
1872         hdr_insert_head(hdr2, de_t, to_copy);
1873
1874         /* Remove all entries (sp including) from hdr1. */
1875         used = used1 - to_copy - sp_size;
1876         memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off));
1877         hdr1->used = cpu_to_le32(used);
1878
1879         /*
1880          * Insert new entry into left or right buffer
1881          * (depending on sp <=> new_de).
1882          */
1883         hdr_insert_de(indx,
1884                       (*indx->cmp)(new_de + 1, le16_to_cpu(new_de->key_size),
1885                                    up_e + 1, le16_to_cpu(up_e->key_size),
1886                                    ctx) < 0 ?
1887                               hdr2 :
1888                               hdr1,
1889                       new_de, NULL, ctx);
1890
1891         indx_mark_used(indx, ni, new_vbn >> indx->idx2vbn_bits);
1892
1893         indx_write(indx, ni, n1, 0);
1894         indx_write(indx, ni, n2, 0);
1895
1896         put_indx_node(n2);
1897
1898         /*
1899          * We've finished splitting everybody, so we are ready to
1900          * insert the promoted entry into the parent.
1901          */
1902         if (!level) {
1903                 /* Insert in root. */
1904                 err = indx_insert_into_root(indx, ni, up_e, NULL, ctx, fnd, 0);
1905         } else {
1906                 /*
1907                  * The target buffer's parent is another index buffer.
1908                  * TODO: Remove recursion.
1909                  */
1910                 err = indx_insert_into_buffer(indx, ni, root, up_e, ctx,
1911                                               level - 1, fnd);
1912         }
1913
1914         if (err) {
1915                 /*
1916                  * Undo critical operations.
1917                  */
1918                 indx_mark_free(indx, ni, new_vbn >> indx->idx2vbn_bits);
1919                 memcpy(hdr1, hdr1_saved, used1);
1920                 indx_write(indx, ni, n1, 0);
1921         }
1922
1923 out:
1924         kfree(up_e);
1925         kfree(hdr1_saved);
1926
1927         return err;
1928 }
1929
1930 /*
1931  * indx_insert_entry - Insert new entry into index.
1932  *
1933  * @undo - True if we undoing previous remove.
1934  */
1935 int indx_insert_entry(struct ntfs_index *indx, struct ntfs_inode *ni,
1936                       const struct NTFS_DE *new_de, const void *ctx,
1937                       struct ntfs_fnd *fnd, bool undo)
1938 {
1939         int err;
1940         int diff;
1941         struct NTFS_DE *e;
1942         struct ntfs_fnd *fnd_a = NULL;
1943         struct INDEX_ROOT *root;
1944
1945         if (!fnd) {
1946                 fnd_a = fnd_get();
1947                 if (!fnd_a) {
1948                         err = -ENOMEM;
1949                         goto out1;
1950                 }
1951                 fnd = fnd_a;
1952         }
1953
1954         root = indx_get_root(indx, ni, NULL, NULL);
1955         if (!root) {
1956                 err = -EINVAL;
1957                 goto out;
1958         }
1959
1960         if (fnd_is_empty(fnd)) {
1961                 /*
1962                  * Find the spot the tree where we want to
1963                  * insert the new entry.
1964                  */
1965                 err = indx_find(indx, ni, root, new_de + 1,
1966                                 le16_to_cpu(new_de->key_size), ctx, &diff, &e,
1967                                 fnd);
1968                 if (err)
1969                         goto out;
1970
1971                 if (!diff) {
1972                         err = -EEXIST;
1973                         goto out;
1974                 }
1975         }
1976
1977         if (!fnd->level) {
1978                 /*
1979                  * The root is also a leaf, so we'll insert the
1980                  * new entry into it.
1981                  */
1982                 err = indx_insert_into_root(indx, ni, new_de, fnd->root_de, ctx,
1983                                             fnd, undo);
1984         } else {
1985                 /*
1986                  * Found a leaf buffer, so we'll insert the new entry into it.
1987                  */
1988                 err = indx_insert_into_buffer(indx, ni, root, new_de, ctx,
1989                                               fnd->level - 1, fnd);
1990         }
1991
1992 out:
1993         fnd_put(fnd_a);
1994 out1:
1995         return err;
1996 }
1997
1998 /*
1999  * indx_find_buffer - Locate a buffer from the tree.
2000  */
2001 static struct indx_node *indx_find_buffer(struct ntfs_index *indx,
2002                                           struct ntfs_inode *ni,
2003                                           const struct INDEX_ROOT *root,
2004                                           __le64 vbn, struct indx_node *n)
2005 {
2006         int err;
2007         const struct NTFS_DE *e;
2008         struct indx_node *r;
2009         const struct INDEX_HDR *hdr = n ? &n->index->ihdr : &root->ihdr;
2010
2011         /* Step 1: Scan one level. */
2012         for (e = hdr_first_de(hdr);; e = hdr_next_de(hdr, e)) {
2013                 if (!e)
2014                         return ERR_PTR(-EINVAL);
2015
2016                 if (de_has_vcn(e) && vbn == de_get_vbn_le(e))
2017                         return n;
2018
2019                 if (de_is_last(e))
2020                         break;
2021         }
2022
2023         /* Step2: Do recursion. */
2024         e = Add2Ptr(hdr, le32_to_cpu(hdr->de_off));
2025         for (;;) {
2026                 if (de_has_vcn_ex(e)) {
2027                         err = indx_read(indx, ni, de_get_vbn(e), &n);
2028                         if (err)
2029                                 return ERR_PTR(err);
2030
2031                         r = indx_find_buffer(indx, ni, root, vbn, n);
2032                         if (r)
2033                                 return r;
2034                 }
2035
2036                 if (de_is_last(e))
2037                         break;
2038
2039                 e = Add2Ptr(e, le16_to_cpu(e->size));
2040         }
2041
2042         return NULL;
2043 }
2044
2045 /*
2046  * indx_shrink - Deallocate unused tail indexes.
2047  */
2048 static int indx_shrink(struct ntfs_index *indx, struct ntfs_inode *ni,
2049                        size_t bit)
2050 {
2051         int err = 0;
2052         u64 bpb, new_data;
2053         size_t nbits;
2054         struct ATTRIB *b;
2055         struct ATTR_LIST_ENTRY *le = NULL;
2056         const struct INDEX_NAMES *in = &s_index_names[indx->type];
2057
2058         b = ni_find_attr(ni, NULL, &le, ATTR_BITMAP, in->name, in->name_len,
2059                          NULL, NULL);
2060
2061         if (!b)
2062                 return -ENOENT;
2063
2064         if (!b->non_res) {
2065                 unsigned long pos;
2066                 const unsigned long *bm = resident_data(b);
2067
2068                 nbits = (size_t)le32_to_cpu(b->res.data_size) * 8;
2069
2070                 if (bit >= nbits)
2071                         return 0;
2072
2073                 pos = find_next_bit_le(bm, nbits, bit);
2074                 if (pos < nbits)
2075                         return 0;
2076         } else {
2077                 size_t used = MINUS_ONE_T;
2078
2079                 nbits = le64_to_cpu(b->nres.data_size) * 8;
2080
2081                 if (bit >= nbits)
2082                         return 0;
2083
2084                 err = scan_nres_bitmap(ni, b, indx, bit, &scan_for_used, &used);
2085                 if (err)
2086                         return err;
2087
2088                 if (used != MINUS_ONE_T)
2089                         return 0;
2090         }
2091
2092         new_data = (u64)bit << indx->index_bits;
2093
2094         err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
2095                             &indx->alloc_run, new_data, &new_data, false, NULL);
2096         if (err)
2097                 return err;
2098
2099         if (in->name == I30_NAME)
2100                 i_size_write(&ni->vfs_inode, new_data);
2101
2102         bpb = ntfs3_bitmap_size(bit);
2103         if (bpb * 8 == nbits)
2104                 return 0;
2105
2106         err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
2107                             &indx->bitmap_run, bpb, &bpb, false, NULL);
2108
2109         return err;
2110 }
2111
2112 static int indx_free_children(struct ntfs_index *indx, struct ntfs_inode *ni,
2113                               const struct NTFS_DE *e, bool trim)
2114 {
2115         int err;
2116         struct indx_node *n = NULL;
2117         struct INDEX_HDR *hdr;
2118         CLST vbn = de_get_vbn(e);
2119         size_t i;
2120
2121         err = indx_read(indx, ni, vbn, &n);
2122         if (err)
2123                 return err;
2124
2125         hdr = &n->index->ihdr;
2126         /* First, recurse into the children, if any. */
2127         if (hdr_has_subnode(hdr)) {
2128                 for (e = hdr_first_de(hdr); e; e = hdr_next_de(hdr, e)) {
2129                         indx_free_children(indx, ni, e, false);
2130                         if (de_is_last(e))
2131                                 break;
2132                 }
2133         }
2134
2135         put_indx_node(n);
2136
2137         i = vbn >> indx->idx2vbn_bits;
2138         /*
2139          * We've gotten rid of the children; add this buffer to the free list.
2140          */
2141         indx_mark_free(indx, ni, i);
2142
2143         if (!trim)
2144                 return 0;
2145
2146         /*
2147          * If there are no used indexes after current free index
2148          * then we can truncate allocation and bitmap.
2149          * Use bitmap to estimate the case.
2150          */
2151         indx_shrink(indx, ni, i + 1);
2152         return 0;
2153 }
2154
2155 /*
2156  * indx_get_entry_to_replace
2157  *
2158  * Find a replacement entry for a deleted entry.
2159  * Always returns a node entry:
2160  * NTFS_IE_HAS_SUBNODES is set the flags and the size includes the sub_vcn.
2161  */
2162 static int indx_get_entry_to_replace(struct ntfs_index *indx,
2163                                      struct ntfs_inode *ni,
2164                                      const struct NTFS_DE *de_next,
2165                                      struct NTFS_DE **de_to_replace,
2166                                      struct ntfs_fnd *fnd)
2167 {
2168         int err;
2169         int level = -1;
2170         CLST vbn;
2171         struct NTFS_DE *e, *te, *re;
2172         struct indx_node *n;
2173         struct INDEX_BUFFER *ib;
2174
2175         *de_to_replace = NULL;
2176
2177         /* Find first leaf entry down from de_next. */
2178         vbn = de_get_vbn(de_next);
2179         for (;;) {
2180                 n = NULL;
2181                 err = indx_read(indx, ni, vbn, &n);
2182                 if (err)
2183                         goto out;
2184
2185                 e = hdr_first_de(&n->index->ihdr);
2186                 fnd_push(fnd, n, e);
2187
2188                 if (!de_is_last(e)) {
2189                         /*
2190                          * This buffer is non-empty, so its first entry
2191                          * could be used as the replacement entry.
2192                          */
2193                         level = fnd->level - 1;
2194                 }
2195
2196                 if (!de_has_vcn(e))
2197                         break;
2198
2199                 /* This buffer is a node. Continue to go down. */
2200                 vbn = de_get_vbn(e);
2201         }
2202
2203         if (level == -1)
2204                 goto out;
2205
2206         n = fnd->nodes[level];
2207         te = hdr_first_de(&n->index->ihdr);
2208         /* Copy the candidate entry into the replacement entry buffer. */
2209         re = kmalloc(le16_to_cpu(te->size) + sizeof(u64), GFP_NOFS);
2210         if (!re) {
2211                 err = -ENOMEM;
2212                 goto out;
2213         }
2214
2215         *de_to_replace = re;
2216         memcpy(re, te, le16_to_cpu(te->size));
2217
2218         if (!de_has_vcn(re)) {
2219                 /*
2220                  * The replacement entry we found doesn't have a sub_vcn.
2221                  * increase its size to hold one.
2222                  */
2223                 le16_add_cpu(&re->size, sizeof(u64));
2224                 re->flags |= NTFS_IE_HAS_SUBNODES;
2225         } else {
2226                 /*
2227                  * The replacement entry we found was a node entry, which
2228                  * means that all its child buffers are empty. Return them
2229                  * to the free pool.
2230                  */
2231                 indx_free_children(indx, ni, te, true);
2232         }
2233
2234         /*
2235          * Expunge the replacement entry from its former location,
2236          * and then write that buffer.
2237          */
2238         ib = n->index;
2239         e = hdr_delete_de(&ib->ihdr, te);
2240
2241         fnd->de[level] = e;
2242         indx_write(indx, ni, n, 0);
2243
2244         if (ib_is_leaf(ib) && ib_is_empty(ib)) {
2245                 /* An empty leaf. */
2246                 return 0;
2247         }
2248
2249 out:
2250         fnd_clear(fnd);
2251         return err;
2252 }
2253
2254 /*
2255  * indx_delete_entry - Delete an entry from the index.
2256  */
2257 int indx_delete_entry(struct ntfs_index *indx, struct ntfs_inode *ni,
2258                       const void *key, u32 key_len, const void *ctx)
2259 {
2260         int err, diff;
2261         struct INDEX_ROOT *root;
2262         struct INDEX_HDR *hdr;
2263         struct ntfs_fnd *fnd, *fnd2;
2264         struct INDEX_BUFFER *ib;
2265         struct NTFS_DE *e, *re, *next, *prev, *me;
2266         struct indx_node *n, *n2d = NULL;
2267         __le64 sub_vbn;
2268         int level, level2;
2269         struct ATTRIB *attr;
2270         struct mft_inode *mi;
2271         u32 e_size, root_size, new_root_size;
2272         size_t trim_bit;
2273         const struct INDEX_NAMES *in;
2274
2275         fnd = fnd_get();
2276         if (!fnd) {
2277                 err = -ENOMEM;
2278                 goto out2;
2279         }
2280
2281         fnd2 = fnd_get();
2282         if (!fnd2) {
2283                 err = -ENOMEM;
2284                 goto out1;
2285         }
2286
2287         root = indx_get_root(indx, ni, &attr, &mi);
2288         if (!root) {
2289                 err = -EINVAL;
2290                 goto out;
2291         }
2292
2293         /* Locate the entry to remove. */
2294         err = indx_find(indx, ni, root, key, key_len, ctx, &diff, &e, fnd);
2295         if (err)
2296                 goto out;
2297
2298         if (!e || diff) {
2299                 err = -ENOENT;
2300                 goto out;
2301         }
2302
2303         level = fnd->level;
2304
2305         if (level) {
2306                 n = fnd->nodes[level - 1];
2307                 e = fnd->de[level - 1];
2308                 ib = n->index;
2309                 hdr = &ib->ihdr;
2310         } else {
2311                 hdr = &root->ihdr;
2312                 e = fnd->root_de;
2313                 n = NULL;
2314         }
2315
2316         e_size = le16_to_cpu(e->size);
2317
2318         if (!de_has_vcn_ex(e)) {
2319                 /* The entry to delete is a leaf, so we can just rip it out. */
2320                 hdr_delete_de(hdr, e);
2321
2322                 if (!level) {
2323                         hdr->total = hdr->used;
2324
2325                         /* Shrink resident root attribute. */
2326                         mi_resize_attr(mi, attr, 0 - e_size);
2327                         goto out;
2328                 }
2329
2330                 indx_write(indx, ni, n, 0);
2331
2332                 /*
2333                  * Check to see if removing that entry made
2334                  * the leaf empty.
2335                  */
2336                 if (ib_is_leaf(ib) && ib_is_empty(ib)) {
2337                         fnd_pop(fnd);
2338                         fnd_push(fnd2, n, e);
2339                 }
2340         } else {
2341                 /*
2342                  * The entry we wish to delete is a node buffer, so we
2343                  * have to find a replacement for it.
2344                  */
2345                 next = de_get_next(e);
2346
2347                 err = indx_get_entry_to_replace(indx, ni, next, &re, fnd2);
2348                 if (err)
2349                         goto out;
2350
2351                 if (re) {
2352                         de_set_vbn_le(re, de_get_vbn_le(e));
2353                         hdr_delete_de(hdr, e);
2354
2355                         err = level ? indx_insert_into_buffer(indx, ni, root,
2356                                                               re, ctx,
2357                                                               fnd->level - 1,
2358                                                               fnd) :
2359                                       indx_insert_into_root(indx, ni, re, e,
2360                                                             ctx, fnd, 0);
2361                         kfree(re);
2362
2363                         if (err)
2364                                 goto out;
2365                 } else {
2366                         /*
2367                          * There is no replacement for the current entry.
2368                          * This means that the subtree rooted at its node
2369                          * is empty, and can be deleted, which turn means
2370                          * that the node can just inherit the deleted
2371                          * entry sub_vcn.
2372                          */
2373                         indx_free_children(indx, ni, next, true);
2374
2375                         de_set_vbn_le(next, de_get_vbn_le(e));
2376                         hdr_delete_de(hdr, e);
2377                         if (level) {
2378                                 indx_write(indx, ni, n, 0);
2379                         } else {
2380                                 hdr->total = hdr->used;
2381
2382                                 /* Shrink resident root attribute. */
2383                                 mi_resize_attr(mi, attr, 0 - e_size);
2384                         }
2385                 }
2386         }
2387
2388         /* Delete a branch of tree. */
2389         if (!fnd2 || !fnd2->level)
2390                 goto out;
2391
2392         /* Reinit root 'cause it can be changed. */
2393         root = indx_get_root(indx, ni, &attr, &mi);
2394         if (!root) {
2395                 err = -EINVAL;
2396                 goto out;
2397         }
2398
2399         n2d = NULL;
2400         sub_vbn = fnd2->nodes[0]->index->vbn;
2401         level2 = 0;
2402         level = fnd->level;
2403
2404         hdr = level ? &fnd->nodes[level - 1]->index->ihdr : &root->ihdr;
2405
2406         /* Scan current level. */
2407         for (e = hdr_first_de(hdr);; e = hdr_next_de(hdr, e)) {
2408                 if (!e) {
2409                         err = -EINVAL;
2410                         goto out;
2411                 }
2412
2413                 if (de_has_vcn(e) && sub_vbn == de_get_vbn_le(e))
2414                         break;
2415
2416                 if (de_is_last(e)) {
2417                         e = NULL;
2418                         break;
2419                 }
2420         }
2421
2422         if (!e) {
2423                 /* Do slow search from root. */
2424                 struct indx_node *in;
2425
2426                 fnd_clear(fnd);
2427
2428                 in = indx_find_buffer(indx, ni, root, sub_vbn, NULL);
2429                 if (IS_ERR(in)) {
2430                         err = PTR_ERR(in);
2431                         goto out;
2432                 }
2433
2434                 if (in)
2435                         fnd_push(fnd, in, NULL);
2436         }
2437
2438         /* Merge fnd2 -> fnd. */
2439         for (level = 0; level < fnd2->level; level++) {
2440                 fnd_push(fnd, fnd2->nodes[level], fnd2->de[level]);
2441                 fnd2->nodes[level] = NULL;
2442         }
2443         fnd2->level = 0;
2444
2445         hdr = NULL;
2446         for (level = fnd->level; level; level--) {
2447                 struct indx_node *in = fnd->nodes[level - 1];
2448
2449                 ib = in->index;
2450                 if (ib_is_empty(ib)) {
2451                         sub_vbn = ib->vbn;
2452                 } else {
2453                         hdr = &ib->ihdr;
2454                         n2d = in;
2455                         level2 = level;
2456                         break;
2457                 }
2458         }
2459
2460         if (!hdr)
2461                 hdr = &root->ihdr;
2462
2463         e = hdr_first_de(hdr);
2464         if (!e) {
2465                 err = -EINVAL;
2466                 goto out;
2467         }
2468
2469         if (hdr != &root->ihdr || !de_is_last(e)) {
2470                 prev = NULL;
2471                 while (!de_is_last(e)) {
2472                         if (de_has_vcn(e) && sub_vbn == de_get_vbn_le(e))
2473                                 break;
2474                         prev = e;
2475                         e = hdr_next_de(hdr, e);
2476                         if (!e) {
2477                                 err = -EINVAL;
2478                                 goto out;
2479                         }
2480                 }
2481
2482                 if (sub_vbn != de_get_vbn_le(e)) {
2483                         /*
2484                          * Didn't find the parent entry, although this buffer
2485                          * is the parent trail. Something is corrupt.
2486                          */
2487                         err = -EINVAL;
2488                         goto out;
2489                 }
2490
2491                 if (de_is_last(e)) {
2492                         /*
2493                          * Since we can't remove the end entry, we'll remove
2494                          * its predecessor instead. This means we have to
2495                          * transfer the predecessor's sub_vcn to the end entry.
2496                          * Note: This index block is not empty, so the
2497                          * predecessor must exist.
2498                          */
2499                         if (!prev) {
2500                                 err = -EINVAL;
2501                                 goto out;
2502                         }
2503
2504                         if (de_has_vcn(prev)) {
2505                                 de_set_vbn_le(e, de_get_vbn_le(prev));
2506                         } else if (de_has_vcn(e)) {
2507                                 le16_sub_cpu(&e->size, sizeof(u64));
2508                                 e->flags &= ~NTFS_IE_HAS_SUBNODES;
2509                                 le32_sub_cpu(&hdr->used, sizeof(u64));
2510                         }
2511                         e = prev;
2512                 }
2513
2514                 /*
2515                  * Copy the current entry into a temporary buffer (stripping
2516                  * off its down-pointer, if any) and delete it from the current
2517                  * buffer or root, as appropriate.
2518                  */
2519                 e_size = le16_to_cpu(e->size);
2520                 me = kmemdup(e, e_size, GFP_NOFS);
2521                 if (!me) {
2522                         err = -ENOMEM;
2523                         goto out;
2524                 }
2525
2526                 if (de_has_vcn(me)) {
2527                         me->flags &= ~NTFS_IE_HAS_SUBNODES;
2528                         le16_sub_cpu(&me->size, sizeof(u64));
2529                 }
2530
2531                 hdr_delete_de(hdr, e);
2532
2533                 if (hdr == &root->ihdr) {
2534                         level = 0;
2535                         hdr->total = hdr->used;
2536
2537                         /* Shrink resident root attribute. */
2538                         mi_resize_attr(mi, attr, 0 - e_size);
2539                 } else {
2540                         indx_write(indx, ni, n2d, 0);
2541                         level = level2;
2542                 }
2543
2544                 /* Mark unused buffers as free. */
2545                 trim_bit = -1;
2546                 for (; level < fnd->level; level++) {
2547                         ib = fnd->nodes[level]->index;
2548                         if (ib_is_empty(ib)) {
2549                                 size_t k = le64_to_cpu(ib->vbn) >>
2550                                            indx->idx2vbn_bits;
2551
2552                                 indx_mark_free(indx, ni, k);
2553                                 if (k < trim_bit)
2554                                         trim_bit = k;
2555                         }
2556                 }
2557
2558                 fnd_clear(fnd);
2559                 /*fnd->root_de = NULL;*/
2560
2561                 /*
2562                  * Re-insert the entry into the tree.
2563                  * Find the spot the tree where we want to insert the new entry.
2564                  */
2565                 err = indx_insert_entry(indx, ni, me, ctx, fnd, 0);
2566                 kfree(me);
2567                 if (err)
2568                         goto out;
2569
2570                 if (trim_bit != -1)
2571                         indx_shrink(indx, ni, trim_bit);
2572         } else {
2573                 /*
2574                  * This tree needs to be collapsed down to an empty root.
2575                  * Recreate the index root as an empty leaf and free all
2576                  * the bits the index allocation bitmap.
2577                  */
2578                 fnd_clear(fnd);
2579                 fnd_clear(fnd2);
2580
2581                 in = &s_index_names[indx->type];
2582
2583                 err = attr_set_size(ni, ATTR_ALLOC, in->name, in->name_len,
2584                                     &indx->alloc_run, 0, NULL, false, NULL);
2585                 if (in->name == I30_NAME)
2586                         i_size_write(&ni->vfs_inode, 0);
2587
2588                 err = ni_remove_attr(ni, ATTR_ALLOC, in->name, in->name_len,
2589                                      false, NULL);
2590                 run_close(&indx->alloc_run);
2591
2592                 err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
2593                                     &indx->bitmap_run, 0, NULL, false, NULL);
2594                 err = ni_remove_attr(ni, ATTR_BITMAP, in->name, in->name_len,
2595                                      false, NULL);
2596                 run_close(&indx->bitmap_run);
2597
2598                 root = indx_get_root(indx, ni, &attr, &mi);
2599                 if (!root) {
2600                         err = -EINVAL;
2601                         goto out;
2602                 }
2603
2604                 root_size = le32_to_cpu(attr->res.data_size);
2605                 new_root_size =
2606                         sizeof(struct INDEX_ROOT) + sizeof(struct NTFS_DE);
2607
2608                 if (new_root_size != root_size &&
2609                     !mi_resize_attr(mi, attr, new_root_size - root_size)) {
2610                         err = -EINVAL;
2611                         goto out;
2612                 }
2613
2614                 /* Fill first entry. */
2615                 e = (struct NTFS_DE *)(root + 1);
2616                 e->ref.low = 0;
2617                 e->ref.high = 0;
2618                 e->ref.seq = 0;
2619                 e->size = cpu_to_le16(sizeof(struct NTFS_DE));
2620                 e->flags = NTFS_IE_LAST; // 0x02
2621                 e->key_size = 0;
2622                 e->res = 0;
2623
2624                 hdr = &root->ihdr;
2625                 hdr->flags = 0;
2626                 hdr->used = hdr->total = cpu_to_le32(
2627                         new_root_size - offsetof(struct INDEX_ROOT, ihdr));
2628                 mi->dirty = true;
2629         }
2630
2631 out:
2632         fnd_put(fnd2);
2633 out1:
2634         fnd_put(fnd);
2635 out2:
2636         return err;
2637 }
2638
2639 /*
2640  * Update duplicated information in directory entry
2641  * 'dup' - info from MFT record
2642  */
2643 int indx_update_dup(struct ntfs_inode *ni, struct ntfs_sb_info *sbi,
2644                     const struct ATTR_FILE_NAME *fname,
2645                     const struct NTFS_DUP_INFO *dup, int sync)
2646 {
2647         int err, diff;
2648         struct NTFS_DE *e = NULL;
2649         struct ATTR_FILE_NAME *e_fname;
2650         struct ntfs_fnd *fnd;
2651         struct INDEX_ROOT *root;
2652         struct mft_inode *mi;
2653         struct ntfs_index *indx = &ni->dir;
2654
2655         fnd = fnd_get();
2656         if (!fnd)
2657                 return -ENOMEM;
2658
2659         root = indx_get_root(indx, ni, NULL, &mi);
2660         if (!root) {
2661                 err = -EINVAL;
2662                 goto out;
2663         }
2664
2665         /* Find entry in directory. */
2666         err = indx_find(indx, ni, root, fname, fname_full_size(fname), sbi,
2667                         &diff, &e, fnd);
2668         if (err)
2669                 goto out;
2670
2671         if (!e) {
2672                 err = -EINVAL;
2673                 goto out;
2674         }
2675
2676         if (diff) {
2677                 err = -EINVAL;
2678                 goto out;
2679         }
2680
2681         e_fname = (struct ATTR_FILE_NAME *)(e + 1);
2682
2683         if (!memcmp(&e_fname->dup, dup, sizeof(*dup))) {
2684                 /*
2685                  * Nothing to update in index! Try to avoid this call.
2686                  */
2687                 goto out;
2688         }
2689
2690         memcpy(&e_fname->dup, dup, sizeof(*dup));
2691
2692         if (fnd->level) {
2693                 /* Directory entry in index. */
2694                 err = indx_write(indx, ni, fnd->nodes[fnd->level - 1], sync);
2695         } else {
2696                 /* Directory entry in directory MFT record. */
2697                 mi->dirty = true;
2698                 if (sync)
2699                         err = mi_write(mi, 1);
2700                 else
2701                         mark_inode_dirty(&ni->vfs_inode);
2702         }
2703
2704 out:
2705         fnd_put(fnd);
2706         return err;
2707 }