1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * This file is part of UBIFS. 4 * 5 * Copyright (C) 2006-2008 Nokia Corporation. 6 * 7 * Authors: Artem Bityutskiy (Битюцкий Артём) 8 * Adrian Hunter 9 */ 10 11 /* 12 * This file implements UBIFS superblock. The superblock is stored at the first 13 * LEB of the volume and is never changed by UBIFS. Only user-space tools may 14 * change it. The superblock node mostly contains geometry information. 15 */ 16 17 #include "ubifs.h" 18 #include <linux/slab.h> 19 #include <linux/math64.h> 20 #include <linux/uuid.h> 21 22 /* 23 * Default journal size in logical eraseblocks as a percent of total 24 * flash size. 25 */ 26 #define DEFAULT_JNL_PERCENT 5 27 28 /* Default maximum journal size in bytes */ 29 #define DEFAULT_MAX_JNL (32*1024*1024) 30 31 /* Default indexing tree fanout */ 32 #define DEFAULT_FANOUT 8 33 34 /* Default number of data journal heads */ 35 #define DEFAULT_JHEADS_CNT 1 36 37 /* Default positions of different LEBs in the main area */ 38 #define DEFAULT_IDX_LEB 0 39 #define DEFAULT_DATA_LEB 1 40 #define DEFAULT_GC_LEB 2 41 42 /* Default number of LEB numbers in LPT's save table */ 43 #define DEFAULT_LSAVE_CNT 256 44 45 /* Default reserved pool size as a percent of maximum free space */ 46 #define DEFAULT_RP_PERCENT 5 47 48 /* The default maximum size of reserved pool in bytes */ 49 #define DEFAULT_MAX_RP_SIZE (5*1024*1024) 50 51 /* Default time granularity in nanoseconds */ 52 #define DEFAULT_TIME_GRAN 1000000000 53 54 static int get_default_compressor(struct ubifs_info *c) 55 { 56 if (ubifs_compr_present(c, UBIFS_COMPR_LZO)) 57 return UBIFS_COMPR_LZO; 58 59 if (ubifs_compr_present(c, UBIFS_COMPR_ZLIB)) 60 return UBIFS_COMPR_ZLIB; 61 62 return UBIFS_COMPR_NONE; 63 } 64 65 /** 66 * create_default_filesystem - format empty UBI volume. 67 * @c: UBIFS file-system description object 68 * 69 * This function creates default empty file-system. Returns zero in case of 70 * success and a negative error code in case of failure. 71 */ 72 static int create_default_filesystem(struct ubifs_info *c) 73 { 74 struct ubifs_sb_node *sup; 75 struct ubifs_mst_node *mst; 76 struct ubifs_idx_node *idx; 77 struct ubifs_branch *br; 78 struct ubifs_ino_node *ino; 79 struct ubifs_cs_node *cs; 80 union ubifs_key key; 81 int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first; 82 int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0; 83 int min_leb_cnt = UBIFS_MIN_LEB_CNT; 84 int idx_node_size; 85 long long tmp64, main_bytes; 86 __le64 tmp_le64; 87 struct timespec64 ts; 88 u8 hash[UBIFS_HASH_ARR_SZ]; 89 u8 hash_lpt[UBIFS_HASH_ARR_SZ]; 90 91 /* Some functions called from here depend on the @c->key_len filed */ 92 c->key_len = UBIFS_SK_LEN; 93 94 /* 95 * First of all, we have to calculate default file-system geometry - 96 * log size, journal size, etc. 97 */ 98 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT) 99 /* We can first multiply then divide and have no overflow */ 100 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100; 101 else 102 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT; 103 104 if (jnl_lebs < UBIFS_MIN_JNL_LEBS) 105 jnl_lebs = UBIFS_MIN_JNL_LEBS; 106 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL) 107 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size; 108 109 /* 110 * The log should be large enough to fit reference nodes for all bud 111 * LEBs. Because buds do not have to start from the beginning of LEBs 112 * (half of the LEB may contain committed data), the log should 113 * generally be larger, make it twice as large. 114 */ 115 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1; 116 log_lebs = tmp / c->leb_size; 117 /* Plus one LEB reserved for commit */ 118 log_lebs += 1; 119 if (c->leb_cnt - min_leb_cnt > 8) { 120 /* And some extra space to allow writes while committing */ 121 log_lebs += 1; 122 min_leb_cnt += 1; 123 } 124 125 max_buds = jnl_lebs - log_lebs; 126 if (max_buds < UBIFS_MIN_BUD_LEBS) 127 max_buds = UBIFS_MIN_BUD_LEBS; 128 129 /* 130 * Orphan nodes are stored in a separate area. One node can store a lot 131 * of orphan inode numbers, but when new orphan comes we just add a new 132 * orphan node. At some point the nodes are consolidated into one 133 * orphan node. 134 */ 135 orph_lebs = UBIFS_MIN_ORPH_LEBS; 136 if (c->leb_cnt - min_leb_cnt > 1) 137 /* 138 * For debugging purposes it is better to have at least 2 139 * orphan LEBs, because the orphan subsystem would need to do 140 * consolidations and would be stressed more. 141 */ 142 orph_lebs += 1; 143 144 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs; 145 main_lebs -= orph_lebs; 146 147 lpt_first = UBIFS_LOG_LNUM + log_lebs; 148 c->lsave_cnt = DEFAULT_LSAVE_CNT; 149 c->max_leb_cnt = c->leb_cnt; 150 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs, 151 &big_lpt, hash_lpt); 152 if (err) 153 return err; 154 155 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first, 156 lpt_first + lpt_lebs - 1); 157 158 main_first = c->leb_cnt - main_lebs; 159 160 sup = kzalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_KERNEL); 161 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); 162 idx_node_size = ubifs_idx_node_sz(c, 1); 163 idx = kzalloc(ALIGN(idx_node_size, c->min_io_size), GFP_KERNEL); 164 ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL); 165 cs = kzalloc(ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size), GFP_KERNEL); 166 167 if (!sup || !mst || !idx || !ino || !cs) { 168 err = -ENOMEM; 169 goto out; 170 } 171 172 /* Create default superblock */ 173 174 tmp64 = (long long)max_buds * c->leb_size; 175 if (big_lpt) 176 sup_flags |= UBIFS_FLG_BIGLPT; 177 if (ubifs_default_version > 4) 178 sup_flags |= UBIFS_FLG_DOUBLE_HASH; 179 180 if (ubifs_authenticated(c)) { 181 sup_flags |= UBIFS_FLG_AUTHENTICATION; 182 sup->hash_algo = cpu_to_le16(c->auth_hash_algo); 183 err = ubifs_hmac_wkm(c, sup->hmac_wkm); 184 if (err) 185 goto out; 186 } else { 187 sup->hash_algo = cpu_to_le16(0xffff); 188 } 189 190 sup->ch.node_type = UBIFS_SB_NODE; 191 sup->key_hash = UBIFS_KEY_HASH_R5; 192 sup->flags = cpu_to_le32(sup_flags); 193 sup->min_io_size = cpu_to_le32(c->min_io_size); 194 sup->leb_size = cpu_to_le32(c->leb_size); 195 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 196 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt); 197 sup->max_bud_bytes = cpu_to_le64(tmp64); 198 sup->log_lebs = cpu_to_le32(log_lebs); 199 sup->lpt_lebs = cpu_to_le32(lpt_lebs); 200 sup->orph_lebs = cpu_to_le32(orph_lebs); 201 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT); 202 sup->fanout = cpu_to_le32(DEFAULT_FANOUT); 203 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt); 204 sup->fmt_version = cpu_to_le32(ubifs_default_version); 205 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN); 206 if (c->mount_opts.override_compr) 207 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type); 208 else 209 sup->default_compr = cpu_to_le16(get_default_compressor(c)); 210 211 generate_random_uuid(sup->uuid); 212 213 main_bytes = (long long)main_lebs * c->leb_size; 214 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100); 215 if (tmp64 > DEFAULT_MAX_RP_SIZE) 216 tmp64 = DEFAULT_MAX_RP_SIZE; 217 sup->rp_size = cpu_to_le64(tmp64); 218 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION); 219 220 dbg_gen("default superblock created at LEB 0:0"); 221 222 /* Create default master node */ 223 224 mst->ch.node_type = UBIFS_MST_NODE; 225 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM); 226 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO); 227 mst->cmt_no = 0; 228 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); 229 mst->root_offs = 0; 230 tmp = ubifs_idx_node_sz(c, 1); 231 mst->root_len = cpu_to_le32(tmp); 232 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB); 233 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); 234 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size)); 235 mst->index_size = cpu_to_le64(ALIGN(tmp, 8)); 236 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum); 237 mst->lpt_offs = cpu_to_le32(c->lpt_offs); 238 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum); 239 mst->nhead_offs = cpu_to_le32(c->nhead_offs); 240 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum); 241 mst->ltab_offs = cpu_to_le32(c->ltab_offs); 242 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum); 243 mst->lsave_offs = cpu_to_le32(c->lsave_offs); 244 mst->lscan_lnum = cpu_to_le32(main_first); 245 mst->empty_lebs = cpu_to_le32(main_lebs - 2); 246 mst->idx_lebs = cpu_to_le32(1); 247 mst->leb_cnt = cpu_to_le32(c->leb_cnt); 248 ubifs_copy_hash(c, hash_lpt, mst->hash_lpt); 249 250 /* Calculate lprops statistics */ 251 tmp64 = main_bytes; 252 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); 253 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); 254 mst->total_free = cpu_to_le64(tmp64); 255 256 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); 257 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) - 258 UBIFS_INO_NODE_SZ; 259 tmp64 += ino_waste; 260 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8); 261 mst->total_dirty = cpu_to_le64(tmp64); 262 263 /* The indexing LEB does not contribute to dark space */ 264 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm); 265 mst->total_dark = cpu_to_le64(tmp64); 266 267 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); 268 269 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM); 270 271 /* Create the root indexing node */ 272 273 c->key_fmt = UBIFS_SIMPLE_KEY_FMT; 274 c->key_hash = key_r5_hash; 275 276 idx->ch.node_type = UBIFS_IDX_NODE; 277 idx->child_cnt = cpu_to_le16(1); 278 ino_key_init(c, &key, UBIFS_ROOT_INO); 279 br = ubifs_idx_branch(c, idx, 0); 280 key_write_idx(c, &key, &br->key); 281 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB); 282 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ); 283 284 dbg_gen("default root indexing node created LEB %d:0", 285 main_first + DEFAULT_IDX_LEB); 286 287 /* Create default root inode */ 288 289 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO); 290 ino->ch.node_type = UBIFS_INO_NODE; 291 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); 292 ino->nlink = cpu_to_le32(2); 293 294 ktime_get_coarse_real_ts64(&ts); 295 tmp_le64 = cpu_to_le64(ts.tv_sec); 296 ino->atime_sec = tmp_le64; 297 ino->ctime_sec = tmp_le64; 298 ino->mtime_sec = tmp_le64; 299 ino->atime_nsec = 0; 300 ino->ctime_nsec = 0; 301 ino->mtime_nsec = 0; 302 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO); 303 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ); 304 305 /* Set compression enabled by default */ 306 ino->flags = cpu_to_le32(UBIFS_COMPR_FL); 307 308 dbg_gen("root inode created at LEB %d:0", 309 main_first + DEFAULT_DATA_LEB); 310 311 /* 312 * The first node in the log has to be the commit start node. This is 313 * always the case during normal file-system operation. Write a fake 314 * commit start node to the log. 315 */ 316 317 cs->ch.node_type = UBIFS_CS_NODE; 318 319 err = ubifs_write_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 0, 0, 320 offsetof(struct ubifs_sb_node, hmac)); 321 if (err) 322 goto out; 323 324 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ, 325 main_first + DEFAULT_DATA_LEB, 0); 326 if (err) 327 goto out; 328 329 ubifs_node_calc_hash(c, ino, hash); 330 ubifs_copy_hash(c, hash, ubifs_branch_hash(c, br)); 331 332 err = ubifs_write_node(c, idx, idx_node_size, main_first + DEFAULT_IDX_LEB, 0); 333 if (err) 334 goto out; 335 336 ubifs_node_calc_hash(c, idx, hash); 337 ubifs_copy_hash(c, hash, mst->hash_root_idx); 338 339 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0, 340 offsetof(struct ubifs_mst_node, hmac)); 341 if (err) 342 goto out; 343 344 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 345 0, offsetof(struct ubifs_mst_node, hmac)); 346 if (err) 347 goto out; 348 349 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0); 350 if (err) 351 goto out; 352 353 ubifs_msg(c, "default file-system created"); 354 355 err = 0; 356 out: 357 kfree(sup); 358 kfree(mst); 359 kfree(idx); 360 kfree(ino); 361 kfree(cs); 362 363 return err; 364 } 365 366 /** 367 * validate_sb - validate superblock node. 368 * @c: UBIFS file-system description object 369 * @sup: superblock node 370 * 371 * This function validates superblock node @sup. Since most of data was read 372 * from the superblock and stored in @c, the function validates fields in @c 373 * instead. Returns zero in case of success and %-EINVAL in case of validation 374 * failure. 375 */ 376 static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup) 377 { 378 long long max_bytes; 379 int err = 1, min_leb_cnt; 380 381 if (!c->key_hash) { 382 err = 2; 383 goto failed; 384 } 385 386 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) { 387 err = 3; 388 goto failed; 389 } 390 391 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) { 392 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real", 393 le32_to_cpu(sup->min_io_size), c->min_io_size); 394 goto failed; 395 } 396 397 if (le32_to_cpu(sup->leb_size) != c->leb_size) { 398 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real", 399 le32_to_cpu(sup->leb_size), c->leb_size); 400 goto failed; 401 } 402 403 if (c->log_lebs < UBIFS_MIN_LOG_LEBS || 404 c->lpt_lebs < UBIFS_MIN_LPT_LEBS || 405 c->orph_lebs < UBIFS_MIN_ORPH_LEBS || 406 c->main_lebs < UBIFS_MIN_MAIN_LEBS) { 407 err = 4; 408 goto failed; 409 } 410 411 /* 412 * Calculate minimum allowed amount of main area LEBs. This is very 413 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we 414 * have just read from the superblock. 415 */ 416 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs; 417 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6; 418 419 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) { 420 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required", 421 c->leb_cnt, c->vi.size, min_leb_cnt); 422 goto failed; 423 } 424 425 if (c->max_leb_cnt < c->leb_cnt) { 426 ubifs_err(c, "max. LEB count %d less than LEB count %d", 427 c->max_leb_cnt, c->leb_cnt); 428 goto failed; 429 } 430 431 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) { 432 ubifs_err(c, "too few main LEBs count %d, must be at least %d", 433 c->main_lebs, UBIFS_MIN_MAIN_LEBS); 434 goto failed; 435 } 436 437 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS; 438 if (c->max_bud_bytes < max_bytes) { 439 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes", 440 c->max_bud_bytes, max_bytes); 441 goto failed; 442 } 443 444 max_bytes = (long long)c->leb_size * c->main_lebs; 445 if (c->max_bud_bytes > max_bytes) { 446 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area", 447 c->max_bud_bytes, max_bytes); 448 goto failed; 449 } 450 451 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 || 452 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) { 453 err = 9; 454 goto failed; 455 } 456 457 if (c->fanout < UBIFS_MIN_FANOUT || 458 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) { 459 err = 10; 460 goto failed; 461 } 462 463 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT && 464 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - 465 c->log_lebs - c->lpt_lebs - c->orph_lebs)) { 466 err = 11; 467 goto failed; 468 } 469 470 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs + 471 c->orph_lebs + c->main_lebs != c->leb_cnt) { 472 err = 12; 473 goto failed; 474 } 475 476 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) { 477 err = 13; 478 goto failed; 479 } 480 481 if (c->rp_size < 0 || max_bytes < c->rp_size) { 482 err = 14; 483 goto failed; 484 } 485 486 if (le32_to_cpu(sup->time_gran) > 1000000000 || 487 le32_to_cpu(sup->time_gran) < 1) { 488 err = 15; 489 goto failed; 490 } 491 492 if (!c->double_hash && c->fmt_version >= 5) { 493 err = 16; 494 goto failed; 495 } 496 497 if (c->encrypted && c->fmt_version < 5) { 498 err = 17; 499 goto failed; 500 } 501 502 return 0; 503 504 failed: 505 ubifs_err(c, "bad superblock, error %d", err); 506 ubifs_dump_node(c, sup); 507 return -EINVAL; 508 } 509 510 /** 511 * ubifs_read_sb_node - read superblock node. 512 * @c: UBIFS file-system description object 513 * 514 * This function returns a pointer to the superblock node or a negative error 515 * code. Note, the user of this function is responsible of kfree()'ing the 516 * returned superblock buffer. 517 */ 518 static struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c) 519 { 520 struct ubifs_sb_node *sup; 521 int err; 522 523 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS); 524 if (!sup) 525 return ERR_PTR(-ENOMEM); 526 527 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ, 528 UBIFS_SB_LNUM, 0); 529 if (err) { 530 kfree(sup); 531 return ERR_PTR(err); 532 } 533 534 return sup; 535 } 536 537 static int authenticate_sb_node(struct ubifs_info *c, 538 const struct ubifs_sb_node *sup) 539 { 540 unsigned int sup_flags = le32_to_cpu(sup->flags); 541 u8 hmac_wkm[UBIFS_HMAC_ARR_SZ]; 542 int authenticated = !!(sup_flags & UBIFS_FLG_AUTHENTICATION); 543 int hash_algo; 544 int err; 545 546 if (c->authenticated && !authenticated) { 547 ubifs_err(c, "authenticated FS forced, but found FS without authentication"); 548 return -EINVAL; 549 } 550 551 if (!c->authenticated && authenticated) { 552 ubifs_err(c, "authenticated FS found, but no key given"); 553 return -EINVAL; 554 } 555 556 ubifs_msg(c, "Mounting in %sauthenticated mode", 557 c->authenticated ? "" : "un"); 558 559 if (!c->authenticated) 560 return 0; 561 562 if (!IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) 563 return -EOPNOTSUPP; 564 565 hash_algo = le16_to_cpu(sup->hash_algo); 566 if (hash_algo >= HASH_ALGO__LAST) { 567 ubifs_err(c, "superblock uses unknown hash algo %d", 568 hash_algo); 569 return -EINVAL; 570 } 571 572 if (strcmp(hash_algo_name[hash_algo], c->auth_hash_name)) { 573 ubifs_err(c, "This filesystem uses %s for hashing," 574 " but %s is specified", hash_algo_name[hash_algo], 575 c->auth_hash_name); 576 return -EINVAL; 577 } 578 579 /* 580 * The super block node can either be authenticated by a HMAC or 581 * by a signature in a ubifs_sig_node directly following the 582 * super block node to support offline image creation. 583 */ 584 if (ubifs_hmac_zero(c, sup->hmac)) { 585 err = ubifs_sb_verify_signature(c, sup); 586 } else { 587 err = ubifs_hmac_wkm(c, hmac_wkm); 588 if (err) 589 return err; 590 if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) { 591 ubifs_err(c, "provided key does not fit"); 592 return -ENOKEY; 593 } 594 err = ubifs_node_verify_hmac(c, sup, sizeof(*sup), 595 offsetof(struct ubifs_sb_node, 596 hmac)); 597 } 598 599 if (err) 600 ubifs_err(c, "Failed to authenticate superblock: %d", err); 601 602 return err; 603 } 604 605 /** 606 * ubifs_write_sb_node - write superblock node. 607 * @c: UBIFS file-system description object 608 * @sup: superblock node read with 'ubifs_read_sb_node()' 609 * 610 * This function returns %0 on success and a negative error code on failure. 611 */ 612 int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) 613 { 614 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); 615 int err; 616 617 err = ubifs_prepare_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 618 offsetof(struct ubifs_sb_node, hmac), 1); 619 if (err) 620 return err; 621 622 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len); 623 } 624 625 /** 626 * ubifs_read_superblock - read superblock. 627 * @c: UBIFS file-system description object 628 * 629 * This function finds, reads and checks the superblock. If an empty UBI volume 630 * is being mounted, this function creates default superblock. Returns zero in 631 * case of success, and a negative error code in case of failure. 632 */ 633 int ubifs_read_superblock(struct ubifs_info *c) 634 { 635 int err, sup_flags; 636 struct ubifs_sb_node *sup; 637 638 if (c->empty) { 639 err = create_default_filesystem(c); 640 if (err) 641 return err; 642 } 643 644 sup = ubifs_read_sb_node(c); 645 if (IS_ERR(sup)) 646 return PTR_ERR(sup); 647 648 c->sup_node = sup; 649 650 c->fmt_version = le32_to_cpu(sup->fmt_version); 651 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); 652 653 /* 654 * The software supports all previous versions but not future versions, 655 * due to the unavailability of time-travelling equipment. 656 */ 657 if (c->fmt_version > UBIFS_FORMAT_VERSION) { 658 ubifs_assert(c, !c->ro_media || c->ro_mount); 659 if (!c->ro_mount || 660 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { 661 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d", 662 c->fmt_version, c->ro_compat_version, 663 UBIFS_FORMAT_VERSION, 664 UBIFS_RO_COMPAT_VERSION); 665 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { 666 ubifs_msg(c, "only R/O mounting is possible"); 667 err = -EROFS; 668 } else 669 err = -EINVAL; 670 goto out; 671 } 672 673 /* 674 * The FS is mounted R/O, and the media format is 675 * R/O-compatible with the UBIFS implementation, so we can 676 * mount. 677 */ 678 c->rw_incompat = 1; 679 } 680 681 if (c->fmt_version < 3) { 682 ubifs_err(c, "on-flash format version %d is not supported", 683 c->fmt_version); 684 err = -EINVAL; 685 goto out; 686 } 687 688 switch (sup->key_hash) { 689 case UBIFS_KEY_HASH_R5: 690 c->key_hash = key_r5_hash; 691 c->key_hash_type = UBIFS_KEY_HASH_R5; 692 break; 693 694 case UBIFS_KEY_HASH_TEST: 695 c->key_hash = key_test_hash; 696 c->key_hash_type = UBIFS_KEY_HASH_TEST; 697 break; 698 } 699 700 c->key_fmt = sup->key_fmt; 701 702 switch (c->key_fmt) { 703 case UBIFS_SIMPLE_KEY_FMT: 704 c->key_len = UBIFS_SK_LEN; 705 break; 706 default: 707 ubifs_err(c, "unsupported key format"); 708 err = -EINVAL; 709 goto out; 710 } 711 712 c->leb_cnt = le32_to_cpu(sup->leb_cnt); 713 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); 714 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); 715 c->log_lebs = le32_to_cpu(sup->log_lebs); 716 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); 717 c->orph_lebs = le32_to_cpu(sup->orph_lebs); 718 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; 719 c->fanout = le32_to_cpu(sup->fanout); 720 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); 721 c->rp_size = le64_to_cpu(sup->rp_size); 722 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid)); 723 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid)); 724 sup_flags = le32_to_cpu(sup->flags); 725 if (!c->mount_opts.override_compr) 726 c->default_compr = le16_to_cpu(sup->default_compr); 727 728 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); 729 memcpy(&c->uuid, &sup->uuid, 16); 730 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); 731 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); 732 c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); 733 c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); 734 735 err = authenticate_sb_node(c, sup); 736 if (err) 737 goto out; 738 739 if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { 740 ubifs_err(c, "Unknown feature flags found: %#x", 741 sup_flags & ~UBIFS_FLG_MASK); 742 err = -EINVAL; 743 goto out; 744 } 745 746 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) { 747 ubifs_err(c, "file system contains encrypted files but UBIFS" 748 " was built without crypto support."); 749 err = -EINVAL; 750 goto out; 751 } 752 753 /* Automatically increase file system size to the maximum size */ 754 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { 755 int old_leb_cnt = c->leb_cnt; 756 757 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); 758 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 759 760 c->superblock_need_write = 1; 761 762 dbg_mnt("Auto resizing from %d LEBs to %d LEBs", 763 old_leb_cnt, c->leb_cnt); 764 } 765 766 c->log_bytes = (long long)c->log_lebs * c->leb_size; 767 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; 768 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; 769 c->lpt_last = c->lpt_first + c->lpt_lebs - 1; 770 c->orph_first = c->lpt_last + 1; 771 c->orph_last = c->orph_first + c->orph_lebs - 1; 772 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; 773 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; 774 c->main_first = c->leb_cnt - c->main_lebs; 775 776 err = validate_sb(c, sup); 777 out: 778 return err; 779 } 780 781 /** 782 * fixup_leb - fixup/unmap an LEB containing free space. 783 * @c: UBIFS file-system description object 784 * @lnum: the LEB number to fix up 785 * @len: number of used bytes in LEB (starting at offset 0) 786 * 787 * This function reads the contents of the given LEB number @lnum, then fixes 788 * it up, so that empty min. I/O units in the end of LEB are actually erased on 789 * flash (rather than being just all-0xff real data). If the LEB is completely 790 * empty, it is simply unmapped. 791 */ 792 static int fixup_leb(struct ubifs_info *c, int lnum, int len) 793 { 794 int err; 795 796 ubifs_assert(c, len >= 0); 797 ubifs_assert(c, len % c->min_io_size == 0); 798 ubifs_assert(c, len < c->leb_size); 799 800 if (len == 0) { 801 dbg_mnt("unmap empty LEB %d", lnum); 802 return ubifs_leb_unmap(c, lnum); 803 } 804 805 dbg_mnt("fixup LEB %d, data len %d", lnum, len); 806 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1); 807 if (err) 808 return err; 809 810 return ubifs_leb_change(c, lnum, c->sbuf, len); 811 } 812 813 /** 814 * fixup_free_space - find & remap all LEBs containing free space. 815 * @c: UBIFS file-system description object 816 * 817 * This function walks through all LEBs in the filesystem and fiexes up those 818 * containing free/empty space. 819 */ 820 static int fixup_free_space(struct ubifs_info *c) 821 { 822 int lnum, err = 0; 823 struct ubifs_lprops *lprops; 824 825 ubifs_get_lprops(c); 826 827 /* Fixup LEBs in the master area */ 828 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) { 829 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz); 830 if (err) 831 goto out; 832 } 833 834 /* Unmap unused log LEBs */ 835 lnum = ubifs_next_log_lnum(c, c->lhead_lnum); 836 while (lnum != c->ltail_lnum) { 837 err = fixup_leb(c, lnum, 0); 838 if (err) 839 goto out; 840 lnum = ubifs_next_log_lnum(c, lnum); 841 } 842 843 /* 844 * Fixup the log head which contains the only a CS node at the 845 * beginning. 846 */ 847 err = fixup_leb(c, c->lhead_lnum, 848 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size)); 849 if (err) 850 goto out; 851 852 /* Fixup LEBs in the LPT area */ 853 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { 854 int free = c->ltab[lnum - c->lpt_first].free; 855 856 if (free > 0) { 857 err = fixup_leb(c, lnum, c->leb_size - free); 858 if (err) 859 goto out; 860 } 861 } 862 863 /* Unmap LEBs in the orphans area */ 864 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { 865 err = fixup_leb(c, lnum, 0); 866 if (err) 867 goto out; 868 } 869 870 /* Fixup LEBs in the main area */ 871 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { 872 lprops = ubifs_lpt_lookup(c, lnum); 873 if (IS_ERR(lprops)) { 874 err = PTR_ERR(lprops); 875 goto out; 876 } 877 878 if (lprops->free > 0) { 879 err = fixup_leb(c, lnum, c->leb_size - lprops->free); 880 if (err) 881 goto out; 882 } 883 } 884 885 out: 886 ubifs_release_lprops(c); 887 return err; 888 } 889 890 /** 891 * ubifs_fixup_free_space - find & fix all LEBs with free space. 892 * @c: UBIFS file-system description object 893 * 894 * This function fixes up LEBs containing free space on first mount, if the 895 * appropriate flag was set when the FS was created. Each LEB with one or more 896 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure 897 * the free space is actually erased. E.g., this is necessary for some NAND 898 * chips, since the free space may have been programmed like real "0xff" data 899 * (generating a non-0xff ECC), causing future writes to the not-really-erased 900 * NAND pages to behave badly. After the space is fixed up, the superblock flag 901 * is cleared, so that this is skipped for all future mounts. 902 */ 903 int ubifs_fixup_free_space(struct ubifs_info *c) 904 { 905 int err; 906 struct ubifs_sb_node *sup = c->sup_node; 907 908 ubifs_assert(c, c->space_fixup); 909 ubifs_assert(c, !c->ro_mount); 910 911 ubifs_msg(c, "start fixing up free space"); 912 913 err = fixup_free_space(c); 914 if (err) 915 return err; 916 917 /* Free-space fixup is no longer required */ 918 c->space_fixup = 0; 919 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); 920 921 c->superblock_need_write = 1; 922 923 ubifs_msg(c, "free space fixup complete"); 924 return err; 925 } 926 927 int ubifs_enable_encryption(struct ubifs_info *c) 928 { 929 int err; 930 struct ubifs_sb_node *sup = c->sup_node; 931 932 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) 933 return -EOPNOTSUPP; 934 935 if (c->encrypted) 936 return 0; 937 938 if (c->ro_mount || c->ro_media) 939 return -EROFS; 940 941 if (c->fmt_version < 5) { 942 ubifs_err(c, "on-flash format version 5 is needed for encryption"); 943 return -EINVAL; 944 } 945 946 sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION); 947 948 err = ubifs_write_sb_node(c, sup); 949 if (!err) 950 c->encrypted = 1; 951 952 return err; 953 } 954