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 __le32 tmp_le32; 88 struct timespec64 ts; 89 u8 hash[UBIFS_HASH_ARR_SZ]; 90 u8 hash_lpt[UBIFS_HASH_ARR_SZ]; 91 92 /* Some functions called from here depend on the @c->key_len filed */ 93 c->key_len = UBIFS_SK_LEN; 94 95 /* 96 * First of all, we have to calculate default file-system geometry - 97 * log size, journal size, etc. 98 */ 99 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT) 100 /* We can first multiply then divide and have no overflow */ 101 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100; 102 else 103 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT; 104 105 if (jnl_lebs < UBIFS_MIN_JNL_LEBS) 106 jnl_lebs = UBIFS_MIN_JNL_LEBS; 107 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL) 108 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size; 109 110 /* 111 * The log should be large enough to fit reference nodes for all bud 112 * LEBs. Because buds do not have to start from the beginning of LEBs 113 * (half of the LEB may contain committed data), the log should 114 * generally be larger, make it twice as large. 115 */ 116 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1; 117 log_lebs = tmp / c->leb_size; 118 /* Plus one LEB reserved for commit */ 119 log_lebs += 1; 120 if (c->leb_cnt - min_leb_cnt > 8) { 121 /* And some extra space to allow writes while committing */ 122 log_lebs += 1; 123 min_leb_cnt += 1; 124 } 125 126 max_buds = jnl_lebs - log_lebs; 127 if (max_buds < UBIFS_MIN_BUD_LEBS) 128 max_buds = UBIFS_MIN_BUD_LEBS; 129 130 /* 131 * Orphan nodes are stored in a separate area. One node can store a lot 132 * of orphan inode numbers, but when new orphan comes we just add a new 133 * orphan node. At some point the nodes are consolidated into one 134 * orphan node. 135 */ 136 orph_lebs = UBIFS_MIN_ORPH_LEBS; 137 if (c->leb_cnt - min_leb_cnt > 1) 138 /* 139 * For debugging purposes it is better to have at least 2 140 * orphan LEBs, because the orphan subsystem would need to do 141 * consolidations and would be stressed more. 142 */ 143 orph_lebs += 1; 144 145 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs; 146 main_lebs -= orph_lebs; 147 148 lpt_first = UBIFS_LOG_LNUM + log_lebs; 149 c->lsave_cnt = DEFAULT_LSAVE_CNT; 150 c->max_leb_cnt = c->leb_cnt; 151 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs, 152 &big_lpt, hash_lpt); 153 if (err) 154 return err; 155 156 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first, 157 lpt_first + lpt_lebs - 1); 158 159 main_first = c->leb_cnt - main_lebs; 160 161 sup = kzalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_KERNEL); 162 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); 163 idx_node_size = ubifs_idx_node_sz(c, 1); 164 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL); 165 ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL); 166 cs = kzalloc(ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size), GFP_KERNEL); 167 168 if (!sup || !mst || !idx || !ino || !cs) { 169 err = -ENOMEM; 170 goto out; 171 } 172 173 /* Create default superblock */ 174 175 tmp64 = (long long)max_buds * c->leb_size; 176 if (big_lpt) 177 sup_flags |= UBIFS_FLG_BIGLPT; 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 = 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_FORMAT_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_real_ts64(&ts); 295 ts = timespec64_trunc(ts, DEFAULT_TIME_GRAN); 296 tmp_le64 = cpu_to_le64(ts.tv_sec); 297 ino->atime_sec = tmp_le64; 298 ino->ctime_sec = tmp_le64; 299 ino->mtime_sec = tmp_le64; 300 tmp_le32 = cpu_to_le32(ts.tv_nsec); 301 ino->atime_nsec = tmp_le32; 302 ino->ctime_nsec = tmp_le32; 303 ino->mtime_nsec = tmp_le32; 304 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO); 305 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ); 306 307 /* Set compression enabled by default */ 308 ino->flags = cpu_to_le32(UBIFS_COMPR_FL); 309 310 dbg_gen("root inode created at LEB %d:0", 311 main_first + DEFAULT_DATA_LEB); 312 313 /* 314 * The first node in the log has to be the commit start node. This is 315 * always the case during normal file-system operation. Write a fake 316 * commit start node to the log. 317 */ 318 319 cs->ch.node_type = UBIFS_CS_NODE; 320 321 err = ubifs_write_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 0, 0, 322 offsetof(struct ubifs_sb_node, hmac)); 323 if (err) 324 goto out; 325 326 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ, 327 main_first + DEFAULT_DATA_LEB, 0); 328 if (err) 329 goto out; 330 331 ubifs_node_calc_hash(c, ino, hash); 332 ubifs_copy_hash(c, hash, ubifs_branch_hash(c, br)); 333 334 err = ubifs_write_node(c, idx, idx_node_size, main_first + DEFAULT_IDX_LEB, 0); 335 if (err) 336 goto out; 337 338 ubifs_node_calc_hash(c, idx, hash); 339 ubifs_copy_hash(c, hash, mst->hash_root_idx); 340 341 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0, 342 offsetof(struct ubifs_mst_node, hmac)); 343 if (err) 344 goto out; 345 346 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 347 0, offsetof(struct ubifs_mst_node, hmac)); 348 if (err) 349 goto out; 350 351 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0); 352 if (err) 353 goto out; 354 355 ubifs_msg(c, "default file-system created"); 356 357 err = 0; 358 out: 359 kfree(sup); 360 kfree(mst); 361 kfree(idx); 362 kfree(ino); 363 kfree(cs); 364 365 return err; 366 } 367 368 /** 369 * validate_sb - validate superblock node. 370 * @c: UBIFS file-system description object 371 * @sup: superblock node 372 * 373 * This function validates superblock node @sup. Since most of data was read 374 * from the superblock and stored in @c, the function validates fields in @c 375 * instead. Returns zero in case of success and %-EINVAL in case of validation 376 * failure. 377 */ 378 static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup) 379 { 380 long long max_bytes; 381 int err = 1, min_leb_cnt; 382 383 if (!c->key_hash) { 384 err = 2; 385 goto failed; 386 } 387 388 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) { 389 err = 3; 390 goto failed; 391 } 392 393 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) { 394 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real", 395 le32_to_cpu(sup->min_io_size), c->min_io_size); 396 goto failed; 397 } 398 399 if (le32_to_cpu(sup->leb_size) != c->leb_size) { 400 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real", 401 le32_to_cpu(sup->leb_size), c->leb_size); 402 goto failed; 403 } 404 405 if (c->log_lebs < UBIFS_MIN_LOG_LEBS || 406 c->lpt_lebs < UBIFS_MIN_LPT_LEBS || 407 c->orph_lebs < UBIFS_MIN_ORPH_LEBS || 408 c->main_lebs < UBIFS_MIN_MAIN_LEBS) { 409 err = 4; 410 goto failed; 411 } 412 413 /* 414 * Calculate minimum allowed amount of main area LEBs. This is very 415 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we 416 * have just read from the superblock. 417 */ 418 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs; 419 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6; 420 421 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) { 422 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required", 423 c->leb_cnt, c->vi.size, min_leb_cnt); 424 goto failed; 425 } 426 427 if (c->max_leb_cnt < c->leb_cnt) { 428 ubifs_err(c, "max. LEB count %d less than LEB count %d", 429 c->max_leb_cnt, c->leb_cnt); 430 goto failed; 431 } 432 433 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) { 434 ubifs_err(c, "too few main LEBs count %d, must be at least %d", 435 c->main_lebs, UBIFS_MIN_MAIN_LEBS); 436 goto failed; 437 } 438 439 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS; 440 if (c->max_bud_bytes < max_bytes) { 441 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes", 442 c->max_bud_bytes, max_bytes); 443 goto failed; 444 } 445 446 max_bytes = (long long)c->leb_size * c->main_lebs; 447 if (c->max_bud_bytes > max_bytes) { 448 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area", 449 c->max_bud_bytes, max_bytes); 450 goto failed; 451 } 452 453 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 || 454 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) { 455 err = 9; 456 goto failed; 457 } 458 459 if (c->fanout < UBIFS_MIN_FANOUT || 460 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) { 461 err = 10; 462 goto failed; 463 } 464 465 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT && 466 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - 467 c->log_lebs - c->lpt_lebs - c->orph_lebs)) { 468 err = 11; 469 goto failed; 470 } 471 472 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs + 473 c->orph_lebs + c->main_lebs != c->leb_cnt) { 474 err = 12; 475 goto failed; 476 } 477 478 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) { 479 err = 13; 480 goto failed; 481 } 482 483 if (c->rp_size < 0 || max_bytes < c->rp_size) { 484 err = 14; 485 goto failed; 486 } 487 488 if (le32_to_cpu(sup->time_gran) > 1000000000 || 489 le32_to_cpu(sup->time_gran) < 1) { 490 err = 15; 491 goto failed; 492 } 493 494 if (!c->double_hash && c->fmt_version >= 5) { 495 err = 16; 496 goto failed; 497 } 498 499 if (c->encrypted && c->fmt_version < 5) { 500 err = 17; 501 goto failed; 502 } 503 504 return 0; 505 506 failed: 507 ubifs_err(c, "bad superblock, error %d", err); 508 ubifs_dump_node(c, sup); 509 return -EINVAL; 510 } 511 512 /** 513 * ubifs_read_sb_node - read superblock node. 514 * @c: UBIFS file-system description object 515 * 516 * This function returns a pointer to the superblock node or a negative error 517 * code. Note, the user of this function is responsible of kfree()'ing the 518 * returned superblock buffer. 519 */ 520 static struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c) 521 { 522 struct ubifs_sb_node *sup; 523 int err; 524 525 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS); 526 if (!sup) 527 return ERR_PTR(-ENOMEM); 528 529 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ, 530 UBIFS_SB_LNUM, 0); 531 if (err) { 532 kfree(sup); 533 return ERR_PTR(err); 534 } 535 536 return sup; 537 } 538 539 static int authenticate_sb_node(struct ubifs_info *c, 540 const struct ubifs_sb_node *sup) 541 { 542 unsigned int sup_flags = le32_to_cpu(sup->flags); 543 u8 hmac_wkm[UBIFS_HMAC_ARR_SZ]; 544 int authenticated = !!(sup_flags & UBIFS_FLG_AUTHENTICATION); 545 int hash_algo; 546 int err; 547 548 if (c->authenticated && !authenticated) { 549 ubifs_err(c, "authenticated FS forced, but found FS without authentication"); 550 return -EINVAL; 551 } 552 553 if (!c->authenticated && authenticated) { 554 ubifs_err(c, "authenticated FS found, but no key given"); 555 return -EINVAL; 556 } 557 558 ubifs_msg(c, "Mounting in %sauthenticated mode", 559 c->authenticated ? "" : "un"); 560 561 if (!c->authenticated) 562 return 0; 563 564 if (!IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) 565 return -EOPNOTSUPP; 566 567 hash_algo = le16_to_cpu(sup->hash_algo); 568 if (hash_algo >= HASH_ALGO__LAST) { 569 ubifs_err(c, "superblock uses unknown hash algo %d", 570 hash_algo); 571 return -EINVAL; 572 } 573 574 if (strcmp(hash_algo_name[hash_algo], c->auth_hash_name)) { 575 ubifs_err(c, "This filesystem uses %s for hashing," 576 " but %s is specified", hash_algo_name[hash_algo], 577 c->auth_hash_name); 578 return -EINVAL; 579 } 580 581 /* 582 * The super block node can either be authenticated by a HMAC or 583 * by a signature in a ubifs_sig_node directly following the 584 * super block node to support offline image creation. 585 */ 586 if (ubifs_hmac_zero(c, sup->hmac)) { 587 err = ubifs_sb_verify_signature(c, sup); 588 } else { 589 err = ubifs_hmac_wkm(c, hmac_wkm); 590 if (err) 591 return err; 592 if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) { 593 ubifs_err(c, "provided key does not fit"); 594 return -ENOKEY; 595 } 596 err = ubifs_node_verify_hmac(c, sup, sizeof(*sup), 597 offsetof(struct ubifs_sb_node, 598 hmac)); 599 } 600 601 if (err) 602 ubifs_err(c, "Failed to authenticate superblock: %d", err); 603 604 return err; 605 } 606 607 /** 608 * ubifs_write_sb_node - write superblock node. 609 * @c: UBIFS file-system description object 610 * @sup: superblock node read with 'ubifs_read_sb_node()' 611 * 612 * This function returns %0 on success and a negative error code on failure. 613 */ 614 int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) 615 { 616 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); 617 int err; 618 619 err = ubifs_prepare_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 620 offsetof(struct ubifs_sb_node, hmac), 1); 621 if (err) 622 return err; 623 624 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len); 625 } 626 627 /** 628 * ubifs_read_superblock - read superblock. 629 * @c: UBIFS file-system description object 630 * 631 * This function finds, reads and checks the superblock. If an empty UBI volume 632 * is being mounted, this function creates default superblock. Returns zero in 633 * case of success, and a negative error code in case of failure. 634 */ 635 int ubifs_read_superblock(struct ubifs_info *c) 636 { 637 int err, sup_flags; 638 struct ubifs_sb_node *sup; 639 640 if (c->empty) { 641 err = create_default_filesystem(c); 642 if (err) 643 return err; 644 } 645 646 sup = ubifs_read_sb_node(c); 647 if (IS_ERR(sup)) 648 return PTR_ERR(sup); 649 650 c->sup_node = sup; 651 652 c->fmt_version = le32_to_cpu(sup->fmt_version); 653 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); 654 655 /* 656 * The software supports all previous versions but not future versions, 657 * due to the unavailability of time-travelling equipment. 658 */ 659 if (c->fmt_version > UBIFS_FORMAT_VERSION) { 660 ubifs_assert(c, !c->ro_media || c->ro_mount); 661 if (!c->ro_mount || 662 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { 663 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d", 664 c->fmt_version, c->ro_compat_version, 665 UBIFS_FORMAT_VERSION, 666 UBIFS_RO_COMPAT_VERSION); 667 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { 668 ubifs_msg(c, "only R/O mounting is possible"); 669 err = -EROFS; 670 } else 671 err = -EINVAL; 672 goto out; 673 } 674 675 /* 676 * The FS is mounted R/O, and the media format is 677 * R/O-compatible with the UBIFS implementation, so we can 678 * mount. 679 */ 680 c->rw_incompat = 1; 681 } 682 683 if (c->fmt_version < 3) { 684 ubifs_err(c, "on-flash format version %d is not supported", 685 c->fmt_version); 686 err = -EINVAL; 687 goto out; 688 } 689 690 switch (sup->key_hash) { 691 case UBIFS_KEY_HASH_R5: 692 c->key_hash = key_r5_hash; 693 c->key_hash_type = UBIFS_KEY_HASH_R5; 694 break; 695 696 case UBIFS_KEY_HASH_TEST: 697 c->key_hash = key_test_hash; 698 c->key_hash_type = UBIFS_KEY_HASH_TEST; 699 break; 700 } 701 702 c->key_fmt = sup->key_fmt; 703 704 switch (c->key_fmt) { 705 case UBIFS_SIMPLE_KEY_FMT: 706 c->key_len = UBIFS_SK_LEN; 707 break; 708 default: 709 ubifs_err(c, "unsupported key format"); 710 err = -EINVAL; 711 goto out; 712 } 713 714 c->leb_cnt = le32_to_cpu(sup->leb_cnt); 715 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); 716 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); 717 c->log_lebs = le32_to_cpu(sup->log_lebs); 718 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); 719 c->orph_lebs = le32_to_cpu(sup->orph_lebs); 720 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; 721 c->fanout = le32_to_cpu(sup->fanout); 722 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); 723 c->rp_size = le64_to_cpu(sup->rp_size); 724 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid)); 725 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid)); 726 sup_flags = le32_to_cpu(sup->flags); 727 if (!c->mount_opts.override_compr) 728 c->default_compr = le16_to_cpu(sup->default_compr); 729 730 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); 731 memcpy(&c->uuid, &sup->uuid, 16); 732 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); 733 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); 734 c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); 735 c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); 736 737 err = authenticate_sb_node(c, sup); 738 if (err) 739 goto out; 740 741 if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { 742 ubifs_err(c, "Unknown feature flags found: %#x", 743 sup_flags & ~UBIFS_FLG_MASK); 744 err = -EINVAL; 745 goto out; 746 } 747 748 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) { 749 ubifs_err(c, "file system contains encrypted files but UBIFS" 750 " was built without crypto support."); 751 err = -EINVAL; 752 goto out; 753 } 754 755 /* Automatically increase file system size to the maximum size */ 756 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { 757 int old_leb_cnt = c->leb_cnt; 758 759 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); 760 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 761 762 c->superblock_need_write = 1; 763 764 dbg_mnt("Auto resizing from %d LEBs to %d LEBs", 765 old_leb_cnt, c->leb_cnt); 766 } 767 768 c->log_bytes = (long long)c->log_lebs * c->leb_size; 769 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; 770 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; 771 c->lpt_last = c->lpt_first + c->lpt_lebs - 1; 772 c->orph_first = c->lpt_last + 1; 773 c->orph_last = c->orph_first + c->orph_lebs - 1; 774 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; 775 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; 776 c->main_first = c->leb_cnt - c->main_lebs; 777 778 err = validate_sb(c, sup); 779 out: 780 return err; 781 } 782 783 /** 784 * fixup_leb - fixup/unmap an LEB containing free space. 785 * @c: UBIFS file-system description object 786 * @lnum: the LEB number to fix up 787 * @len: number of used bytes in LEB (starting at offset 0) 788 * 789 * This function reads the contents of the given LEB number @lnum, then fixes 790 * it up, so that empty min. I/O units in the end of LEB are actually erased on 791 * flash (rather than being just all-0xff real data). If the LEB is completely 792 * empty, it is simply unmapped. 793 */ 794 static int fixup_leb(struct ubifs_info *c, int lnum, int len) 795 { 796 int err; 797 798 ubifs_assert(c, len >= 0); 799 ubifs_assert(c, len % c->min_io_size == 0); 800 ubifs_assert(c, len < c->leb_size); 801 802 if (len == 0) { 803 dbg_mnt("unmap empty LEB %d", lnum); 804 return ubifs_leb_unmap(c, lnum); 805 } 806 807 dbg_mnt("fixup LEB %d, data len %d", lnum, len); 808 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1); 809 if (err) 810 return err; 811 812 return ubifs_leb_change(c, lnum, c->sbuf, len); 813 } 814 815 /** 816 * fixup_free_space - find & remap all LEBs containing free space. 817 * @c: UBIFS file-system description object 818 * 819 * This function walks through all LEBs in the filesystem and fiexes up those 820 * containing free/empty space. 821 */ 822 static int fixup_free_space(struct ubifs_info *c) 823 { 824 int lnum, err = 0; 825 struct ubifs_lprops *lprops; 826 827 ubifs_get_lprops(c); 828 829 /* Fixup LEBs in the master area */ 830 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) { 831 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz); 832 if (err) 833 goto out; 834 } 835 836 /* Unmap unused log LEBs */ 837 lnum = ubifs_next_log_lnum(c, c->lhead_lnum); 838 while (lnum != c->ltail_lnum) { 839 err = fixup_leb(c, lnum, 0); 840 if (err) 841 goto out; 842 lnum = ubifs_next_log_lnum(c, lnum); 843 } 844 845 /* 846 * Fixup the log head which contains the only a CS node at the 847 * beginning. 848 */ 849 err = fixup_leb(c, c->lhead_lnum, 850 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size)); 851 if (err) 852 goto out; 853 854 /* Fixup LEBs in the LPT area */ 855 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { 856 int free = c->ltab[lnum - c->lpt_first].free; 857 858 if (free > 0) { 859 err = fixup_leb(c, lnum, c->leb_size - free); 860 if (err) 861 goto out; 862 } 863 } 864 865 /* Unmap LEBs in the orphans area */ 866 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { 867 err = fixup_leb(c, lnum, 0); 868 if (err) 869 goto out; 870 } 871 872 /* Fixup LEBs in the main area */ 873 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { 874 lprops = ubifs_lpt_lookup(c, lnum); 875 if (IS_ERR(lprops)) { 876 err = PTR_ERR(lprops); 877 goto out; 878 } 879 880 if (lprops->free > 0) { 881 err = fixup_leb(c, lnum, c->leb_size - lprops->free); 882 if (err) 883 goto out; 884 } 885 } 886 887 out: 888 ubifs_release_lprops(c); 889 return err; 890 } 891 892 /** 893 * ubifs_fixup_free_space - find & fix all LEBs with free space. 894 * @c: UBIFS file-system description object 895 * 896 * This function fixes up LEBs containing free space on first mount, if the 897 * appropriate flag was set when the FS was created. Each LEB with one or more 898 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure 899 * the free space is actually erased. E.g., this is necessary for some NAND 900 * chips, since the free space may have been programmed like real "0xff" data 901 * (generating a non-0xff ECC), causing future writes to the not-really-erased 902 * NAND pages to behave badly. After the space is fixed up, the superblock flag 903 * is cleared, so that this is skipped for all future mounts. 904 */ 905 int ubifs_fixup_free_space(struct ubifs_info *c) 906 { 907 int err; 908 struct ubifs_sb_node *sup = c->sup_node; 909 910 ubifs_assert(c, c->space_fixup); 911 ubifs_assert(c, !c->ro_mount); 912 913 ubifs_msg(c, "start fixing up free space"); 914 915 err = fixup_free_space(c); 916 if (err) 917 return err; 918 919 /* Free-space fixup is no longer required */ 920 c->space_fixup = 0; 921 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); 922 923 c->superblock_need_write = 1; 924 925 ubifs_msg(c, "free space fixup complete"); 926 return err; 927 } 928 929 int ubifs_enable_encryption(struct ubifs_info *c) 930 { 931 int err; 932 struct ubifs_sb_node *sup = c->sup_node; 933 934 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) 935 return -EOPNOTSUPP; 936 937 if (c->encrypted) 938 return 0; 939 940 if (c->ro_mount || c->ro_media) 941 return -EROFS; 942 943 if (c->fmt_version < 5) { 944 ubifs_err(c, "on-flash format version 5 is needed for encryption"); 945 return -EINVAL; 946 } 947 948 sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION); 949 950 err = ubifs_write_sb_node(c, sup); 951 if (!err) 952 c->encrypted = 1; 953 954 return err; 955 } 956