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