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 err = ubifs_hmac_wkm(c, hmac_wkm); 582 if (err) 583 return err; 584 585 if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) { 586 ubifs_err(c, "provided key does not fit"); 587 return -ENOKEY; 588 } 589 590 err = ubifs_node_verify_hmac(c, sup, sizeof(*sup), 591 offsetof(struct ubifs_sb_node, hmac)); 592 if (err) 593 ubifs_err(c, "Failed to authenticate superblock: %d", err); 594 595 return err; 596 } 597 598 /** 599 * ubifs_write_sb_node - write superblock node. 600 * @c: UBIFS file-system description object 601 * @sup: superblock node read with 'ubifs_read_sb_node()' 602 * 603 * This function returns %0 on success and a negative error code on failure. 604 */ 605 int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) 606 { 607 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); 608 int err; 609 610 err = ubifs_prepare_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 611 offsetof(struct ubifs_sb_node, hmac), 1); 612 if (err) 613 return err; 614 615 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len); 616 } 617 618 /** 619 * ubifs_read_superblock - read superblock. 620 * @c: UBIFS file-system description object 621 * 622 * This function finds, reads and checks the superblock. If an empty UBI volume 623 * is being mounted, this function creates default superblock. Returns zero in 624 * case of success, and a negative error code in case of failure. 625 */ 626 int ubifs_read_superblock(struct ubifs_info *c) 627 { 628 int err, sup_flags; 629 struct ubifs_sb_node *sup; 630 631 if (c->empty) { 632 err = create_default_filesystem(c); 633 if (err) 634 return err; 635 } 636 637 sup = ubifs_read_sb_node(c); 638 if (IS_ERR(sup)) 639 return PTR_ERR(sup); 640 641 c->sup_node = sup; 642 643 c->fmt_version = le32_to_cpu(sup->fmt_version); 644 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); 645 646 /* 647 * The software supports all previous versions but not future versions, 648 * due to the unavailability of time-travelling equipment. 649 */ 650 if (c->fmt_version > UBIFS_FORMAT_VERSION) { 651 ubifs_assert(c, !c->ro_media || c->ro_mount); 652 if (!c->ro_mount || 653 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { 654 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d", 655 c->fmt_version, c->ro_compat_version, 656 UBIFS_FORMAT_VERSION, 657 UBIFS_RO_COMPAT_VERSION); 658 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { 659 ubifs_msg(c, "only R/O mounting is possible"); 660 err = -EROFS; 661 } else 662 err = -EINVAL; 663 goto out; 664 } 665 666 /* 667 * The FS is mounted R/O, and the media format is 668 * R/O-compatible with the UBIFS implementation, so we can 669 * mount. 670 */ 671 c->rw_incompat = 1; 672 } 673 674 if (c->fmt_version < 3) { 675 ubifs_err(c, "on-flash format version %d is not supported", 676 c->fmt_version); 677 err = -EINVAL; 678 goto out; 679 } 680 681 switch (sup->key_hash) { 682 case UBIFS_KEY_HASH_R5: 683 c->key_hash = key_r5_hash; 684 c->key_hash_type = UBIFS_KEY_HASH_R5; 685 break; 686 687 case UBIFS_KEY_HASH_TEST: 688 c->key_hash = key_test_hash; 689 c->key_hash_type = UBIFS_KEY_HASH_TEST; 690 break; 691 } 692 693 c->key_fmt = sup->key_fmt; 694 695 switch (c->key_fmt) { 696 case UBIFS_SIMPLE_KEY_FMT: 697 c->key_len = UBIFS_SK_LEN; 698 break; 699 default: 700 ubifs_err(c, "unsupported key format"); 701 err = -EINVAL; 702 goto out; 703 } 704 705 c->leb_cnt = le32_to_cpu(sup->leb_cnt); 706 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); 707 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); 708 c->log_lebs = le32_to_cpu(sup->log_lebs); 709 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); 710 c->orph_lebs = le32_to_cpu(sup->orph_lebs); 711 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; 712 c->fanout = le32_to_cpu(sup->fanout); 713 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); 714 c->rp_size = le64_to_cpu(sup->rp_size); 715 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid)); 716 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid)); 717 sup_flags = le32_to_cpu(sup->flags); 718 if (!c->mount_opts.override_compr) 719 c->default_compr = le16_to_cpu(sup->default_compr); 720 721 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); 722 memcpy(&c->uuid, &sup->uuid, 16); 723 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); 724 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); 725 c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); 726 c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); 727 728 err = authenticate_sb_node(c, sup); 729 if (err) 730 goto out; 731 732 if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { 733 ubifs_err(c, "Unknown feature flags found: %#x", 734 sup_flags & ~UBIFS_FLG_MASK); 735 err = -EINVAL; 736 goto out; 737 } 738 739 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) { 740 ubifs_err(c, "file system contains encrypted files but UBIFS" 741 " was built without crypto support."); 742 err = -EINVAL; 743 goto out; 744 } 745 746 /* Automatically increase file system size to the maximum size */ 747 c->old_leb_cnt = c->leb_cnt; 748 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { 749 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); 750 if (c->ro_mount) 751 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs", 752 c->old_leb_cnt, c->leb_cnt); 753 else { 754 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs", 755 c->old_leb_cnt, c->leb_cnt); 756 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 757 err = ubifs_write_sb_node(c, sup); 758 if (err) 759 goto out; 760 c->old_leb_cnt = c->leb_cnt; 761 } 762 } 763 764 c->log_bytes = (long long)c->log_lebs * c->leb_size; 765 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; 766 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; 767 c->lpt_last = c->lpt_first + c->lpt_lebs - 1; 768 c->orph_first = c->lpt_last + 1; 769 c->orph_last = c->orph_first + c->orph_lebs - 1; 770 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; 771 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; 772 c->main_first = c->leb_cnt - c->main_lebs; 773 774 err = validate_sb(c, sup); 775 out: 776 return err; 777 } 778 779 /** 780 * fixup_leb - fixup/unmap an LEB containing free space. 781 * @c: UBIFS file-system description object 782 * @lnum: the LEB number to fix up 783 * @len: number of used bytes in LEB (starting at offset 0) 784 * 785 * This function reads the contents of the given LEB number @lnum, then fixes 786 * it up, so that empty min. I/O units in the end of LEB are actually erased on 787 * flash (rather than being just all-0xff real data). If the LEB is completely 788 * empty, it is simply unmapped. 789 */ 790 static int fixup_leb(struct ubifs_info *c, int lnum, int len) 791 { 792 int err; 793 794 ubifs_assert(c, len >= 0); 795 ubifs_assert(c, len % c->min_io_size == 0); 796 ubifs_assert(c, len < c->leb_size); 797 798 if (len == 0) { 799 dbg_mnt("unmap empty LEB %d", lnum); 800 return ubifs_leb_unmap(c, lnum); 801 } 802 803 dbg_mnt("fixup LEB %d, data len %d", lnum, len); 804 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1); 805 if (err) 806 return err; 807 808 return ubifs_leb_change(c, lnum, c->sbuf, len); 809 } 810 811 /** 812 * fixup_free_space - find & remap all LEBs containing free space. 813 * @c: UBIFS file-system description object 814 * 815 * This function walks through all LEBs in the filesystem and fiexes up those 816 * containing free/empty space. 817 */ 818 static int fixup_free_space(struct ubifs_info *c) 819 { 820 int lnum, err = 0; 821 struct ubifs_lprops *lprops; 822 823 ubifs_get_lprops(c); 824 825 /* Fixup LEBs in the master area */ 826 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) { 827 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz); 828 if (err) 829 goto out; 830 } 831 832 /* Unmap unused log LEBs */ 833 lnum = ubifs_next_log_lnum(c, c->lhead_lnum); 834 while (lnum != c->ltail_lnum) { 835 err = fixup_leb(c, lnum, 0); 836 if (err) 837 goto out; 838 lnum = ubifs_next_log_lnum(c, lnum); 839 } 840 841 /* 842 * Fixup the log head which contains the only a CS node at the 843 * beginning. 844 */ 845 err = fixup_leb(c, c->lhead_lnum, 846 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size)); 847 if (err) 848 goto out; 849 850 /* Fixup LEBs in the LPT area */ 851 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { 852 int free = c->ltab[lnum - c->lpt_first].free; 853 854 if (free > 0) { 855 err = fixup_leb(c, lnum, c->leb_size - free); 856 if (err) 857 goto out; 858 } 859 } 860 861 /* Unmap LEBs in the orphans area */ 862 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { 863 err = fixup_leb(c, lnum, 0); 864 if (err) 865 goto out; 866 } 867 868 /* Fixup LEBs in the main area */ 869 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { 870 lprops = ubifs_lpt_lookup(c, lnum); 871 if (IS_ERR(lprops)) { 872 err = PTR_ERR(lprops); 873 goto out; 874 } 875 876 if (lprops->free > 0) { 877 err = fixup_leb(c, lnum, c->leb_size - lprops->free); 878 if (err) 879 goto out; 880 } 881 } 882 883 out: 884 ubifs_release_lprops(c); 885 return err; 886 } 887 888 /** 889 * ubifs_fixup_free_space - find & fix all LEBs with free space. 890 * @c: UBIFS file-system description object 891 * 892 * This function fixes up LEBs containing free space on first mount, if the 893 * appropriate flag was set when the FS was created. Each LEB with one or more 894 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure 895 * the free space is actually erased. E.g., this is necessary for some NAND 896 * chips, since the free space may have been programmed like real "0xff" data 897 * (generating a non-0xff ECC), causing future writes to the not-really-erased 898 * NAND pages to behave badly. After the space is fixed up, the superblock flag 899 * is cleared, so that this is skipped for all future mounts. 900 */ 901 int ubifs_fixup_free_space(struct ubifs_info *c) 902 { 903 int err; 904 struct ubifs_sb_node *sup = c->sup_node; 905 906 ubifs_assert(c, c->space_fixup); 907 ubifs_assert(c, !c->ro_mount); 908 909 ubifs_msg(c, "start fixing up free space"); 910 911 err = fixup_free_space(c); 912 if (err) 913 return err; 914 915 /* Free-space fixup is no longer required */ 916 c->space_fixup = 0; 917 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); 918 919 err = ubifs_write_sb_node(c, sup); 920 if (err) 921 return err; 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