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 (���������������� ����������) 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 54static int get_default_compressor(struct ubifs_info *c) 55{ 56 if (ubifs_compr_present(c, UBIFS_COMPR_ZSTD)) 57 return UBIFS_COMPR_ZSTD; 58 59 if (ubifs_compr_present(c, UBIFS_COMPR_LZO)) 60 return UBIFS_COMPR_LZO; 61 62 if (ubifs_compr_present(c, UBIFS_COMPR_ZLIB)) 63 return UBIFS_COMPR_ZLIB; 64 65 return UBIFS_COMPR_NONE; 66} 67 68/** 69 * create_default_filesystem - format empty UBI volume. 70 * @c: UBIFS file-system description object 71 * 72 * This function creates default empty file-system. Returns zero in case of 73 * success and a negative error code in case of failure. 74 */ 75static int create_default_filesystem(struct ubifs_info *c) 76{ 77 struct ubifs_sb_node *sup; 78 struct ubifs_mst_node *mst; 79 struct ubifs_idx_node *idx; 80 struct ubifs_branch *br; 81 struct ubifs_ino_node *ino; 82 struct ubifs_cs_node *cs; 83 union ubifs_key key; 84 int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first; 85 int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0; 86 int min_leb_cnt = UBIFS_MIN_LEB_CNT; 87 int idx_node_size; 88 long long tmp64, main_bytes; 89 __le64 tmp_le64; 90 struct timespec64 ts; 91 u8 hash[UBIFS_HASH_ARR_SZ]; 92 u8 hash_lpt[UBIFS_HASH_ARR_SZ]; 93 94 /* Some functions called from here depend on the @c->key_len filed */ 95 c->key_len = UBIFS_SK_LEN; 96 97 /* 98 * First of all, we have to calculate default file-system geometry - 99 * log size, journal size, etc. 100 */ 101 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT) 102 /* We can first multiply then divide and have no overflow */ 103 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100; 104 else 105 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT; 106 107 if (jnl_lebs < UBIFS_MIN_JNL_LEBS) 108 jnl_lebs = UBIFS_MIN_JNL_LEBS; 109 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL) 110 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size; 111 112 /* 113 * The log should be large enough to fit reference nodes for all bud 114 * LEBs. Because buds do not have to start from the beginning of LEBs 115 * (half of the LEB may contain committed data), the log should 116 * generally be larger, make it twice as large. 117 */ 118 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1; 119 log_lebs = tmp / c->leb_size; 120 /* Plus one LEB reserved for commit */ 121 log_lebs += 1; 122 if (c->leb_cnt - min_leb_cnt > 8) { 123 /* And some extra space to allow writes while committing */ 124 log_lebs += 1; 125 min_leb_cnt += 1; 126 } 127 128 max_buds = jnl_lebs - log_lebs; 129 if (max_buds < UBIFS_MIN_BUD_LEBS) 130 max_buds = UBIFS_MIN_BUD_LEBS; 131 132 /* 133 * Orphan nodes are stored in a separate area. One node can store a lot 134 * of orphan inode numbers, but when new orphan comes we just add a new 135 * orphan node. At some point the nodes are consolidated into one 136 * orphan node. 137 */ 138 orph_lebs = UBIFS_MIN_ORPH_LEBS; 139 if (c->leb_cnt - min_leb_cnt > 1) 140 /* 141 * For debugging purposes it is better to have at least 2 142 * orphan LEBs, because the orphan subsystem would need to do 143 * consolidations and would be stressed more. 144 */ 145 orph_lebs += 1; 146 147 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs; 148 main_lebs -= orph_lebs; 149 150 lpt_first = UBIFS_LOG_LNUM + log_lebs; 151 c->lsave_cnt = DEFAULT_LSAVE_CNT; 152 c->max_leb_cnt = c->leb_cnt; 153 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs, 154 &big_lpt, hash_lpt); 155 if (err) 156 return err; 157 158 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first, 159 lpt_first + lpt_lebs - 1); 160 161 main_first = c->leb_cnt - main_lebs; 162 163 sup = kzalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_KERNEL); 164 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); 165 idx_node_size = ubifs_idx_node_sz(c, 1); 166 idx = kzalloc(ALIGN(idx_node_size, c->min_io_size), GFP_KERNEL); 167 ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL); 168 cs = kzalloc(ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size), GFP_KERNEL); 169 170 if (!sup || !mst || !idx || !ino || !cs) { 171 err = -ENOMEM; 172 goto out; 173 } 174 175 /* Create default superblock */ 176 177 tmp64 = (long long)max_buds * c->leb_size; 178 if (big_lpt) 179 sup_flags |= UBIFS_FLG_BIGLPT; 180 if (ubifs_default_version > 4) 181 sup_flags |= UBIFS_FLG_DOUBLE_HASH; 182 183 if (ubifs_authenticated(c)) { 184 sup_flags |= UBIFS_FLG_AUTHENTICATION; 185 sup->hash_algo = cpu_to_le16(c->auth_hash_algo); 186 err = ubifs_hmac_wkm(c, sup->hmac_wkm); 187 if (err) 188 goto out; 189 } else { 190 sup->hash_algo = cpu_to_le16(0xffff); 191 } 192 193 sup->ch.node_type = UBIFS_SB_NODE; 194 sup->key_hash = UBIFS_KEY_HASH_R5; 195 sup->flags = cpu_to_le32(sup_flags); 196 sup->min_io_size = cpu_to_le32(c->min_io_size); 197 sup->leb_size = cpu_to_le32(c->leb_size); 198 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 199 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt); 200 sup->max_bud_bytes = cpu_to_le64(tmp64); 201 sup->log_lebs = cpu_to_le32(log_lebs); 202 sup->lpt_lebs = cpu_to_le32(lpt_lebs); 203 sup->orph_lebs = cpu_to_le32(orph_lebs); 204 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT); 205 sup->fanout = cpu_to_le32(DEFAULT_FANOUT); 206 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt); 207 sup->fmt_version = cpu_to_le32(ubifs_default_version); 208 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN); 209 if (c->mount_opts.override_compr) 210 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type); 211 else 212 sup->default_compr = cpu_to_le16(get_default_compressor(c)); 213 214 generate_random_uuid(sup->uuid); 215 216 main_bytes = (long long)main_lebs * c->leb_size; 217 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100); 218 if (tmp64 > DEFAULT_MAX_RP_SIZE) 219 tmp64 = DEFAULT_MAX_RP_SIZE; 220 sup->rp_size = cpu_to_le64(tmp64); 221 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION); 222 223 dbg_gen("default superblock created at LEB 0:0"); 224 225 /* Create default master node */ 226 227 mst->ch.node_type = UBIFS_MST_NODE; 228 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM); 229 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO); 230 mst->cmt_no = 0; 231 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); 232 mst->root_offs = 0; 233 tmp = ubifs_idx_node_sz(c, 1); 234 mst->root_len = cpu_to_le32(tmp); 235 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB); 236 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); 237 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size)); 238 mst->index_size = cpu_to_le64(ALIGN(tmp, 8)); 239 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum); 240 mst->lpt_offs = cpu_to_le32(c->lpt_offs); 241 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum); 242 mst->nhead_offs = cpu_to_le32(c->nhead_offs); 243 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum); 244 mst->ltab_offs = cpu_to_le32(c->ltab_offs); 245 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum); 246 mst->lsave_offs = cpu_to_le32(c->lsave_offs); 247 mst->lscan_lnum = cpu_to_le32(main_first); 248 mst->empty_lebs = cpu_to_le32(main_lebs - 2); 249 mst->idx_lebs = cpu_to_le32(1); 250 mst->leb_cnt = cpu_to_le32(c->leb_cnt); 251 ubifs_copy_hash(c, hash_lpt, mst->hash_lpt); 252 253 /* Calculate lprops statistics */ 254 tmp64 = main_bytes; 255 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); 256 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); 257 mst->total_free = cpu_to_le64(tmp64); 258 259 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); 260 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) - 261 UBIFS_INO_NODE_SZ; 262 tmp64 += ino_waste; 263 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8); 264 mst->total_dirty = cpu_to_le64(tmp64); 265 266 /* The indexing LEB does not contribute to dark space */ 267 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm); 268 mst->total_dark = cpu_to_le64(tmp64); 269 270 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); 271 272 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM); 273 274 /* Create the root indexing node */ 275 276 c->key_fmt = UBIFS_SIMPLE_KEY_FMT; 277 c->key_hash = key_r5_hash; 278 279 idx->ch.node_type = UBIFS_IDX_NODE; 280 idx->child_cnt = cpu_to_le16(1); 281 ino_key_init(c, &key, UBIFS_ROOT_INO); 282 br = ubifs_idx_branch(c, idx, 0); 283 key_write_idx(c, &key, &br->key); 284 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB); 285 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ); 286 287 dbg_gen("default root indexing node created LEB %d:0", 288 main_first + DEFAULT_IDX_LEB); 289 290 /* Create default root inode */ 291 292 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO); 293 ino->ch.node_type = UBIFS_INO_NODE; 294 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); 295 ino->nlink = cpu_to_le32(2); 296 297 ktime_get_coarse_real_ts64(&ts); 298 tmp_le64 = cpu_to_le64(ts.tv_sec); 299 ino->atime_sec = tmp_le64; 300 ino->ctime_sec = tmp_le64; 301 ino->mtime_sec = tmp_le64; 302 ino->atime_nsec = 0; 303 ino->ctime_nsec = 0; 304 ino->mtime_nsec = 0; 305 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO); 306 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ); 307 308 /* Set compression enabled by default */ 309 ino->flags = cpu_to_le32(UBIFS_COMPR_FL); 310 311 dbg_gen("root inode created at LEB %d:0", 312 main_first + DEFAULT_DATA_LEB); 313 314 /* 315 * The first node in the log has to be the commit start node. This is 316 * always the case during normal file-system operation. Write a fake 317 * commit start node to the log. 318 */ 319 320 cs->ch.node_type = UBIFS_CS_NODE; 321 322 err = ubifs_write_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 0, 0, 323 offsetof(struct ubifs_sb_node, hmac)); 324 if (err) 325 goto out; 326 327 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ, 328 main_first + DEFAULT_DATA_LEB, 0); 329 if (err) 330 goto out; 331 332 ubifs_node_calc_hash(c, ino, hash); 333 ubifs_copy_hash(c, hash, ubifs_branch_hash(c, br)); 334 335 err = ubifs_write_node(c, idx, idx_node_size, main_first + DEFAULT_IDX_LEB, 0); 336 if (err) 337 goto out; 338 339 ubifs_node_calc_hash(c, idx, hash); 340 ubifs_copy_hash(c, hash, mst->hash_root_idx); 341 342 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0, 343 offsetof(struct ubifs_mst_node, hmac)); 344 if (err) 345 goto out; 346 347 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 348 0, offsetof(struct ubifs_mst_node, hmac)); 349 if (err) 350 goto out; 351 352 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0); 353 if (err) 354 goto out; 355 356 ubifs_msg(c, "default file-system created"); 357 358 err = 0; 359out: 360 kfree(sup); 361 kfree(mst); 362 kfree(idx); 363 kfree(ino); 364 kfree(cs); 365 366 return err; 367} 368 369/** 370 * validate_sb - validate superblock node. 371 * @c: UBIFS file-system description object 372 * @sup: superblock node 373 * 374 * This function validates superblock node @sup. Since most of data was read 375 * from the superblock and stored in @c, the function validates fields in @c 376 * instead. Returns zero in case of success and %-EINVAL in case of validation 377 * failure. 378 */ 379static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup) 380{ 381 long long max_bytes; 382 int err = 1, min_leb_cnt; 383 384 if (!c->key_hash) { 385 err = 2; 386 goto failed; 387 } 388 389 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) { 390 err = 3; 391 goto failed; 392 } 393 394 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) { 395 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real", 396 le32_to_cpu(sup->min_io_size), c->min_io_size); 397 goto failed; 398 } 399 400 if (le32_to_cpu(sup->leb_size) != c->leb_size) { 401 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real", 402 le32_to_cpu(sup->leb_size), c->leb_size); 403 goto failed; 404 } 405 406 if (c->log_lebs < UBIFS_MIN_LOG_LEBS || 407 c->lpt_lebs < UBIFS_MIN_LPT_LEBS || 408 c->orph_lebs < UBIFS_MIN_ORPH_LEBS || 409 c->main_lebs < UBIFS_MIN_MAIN_LEBS) { 410 err = 4; 411 goto failed; 412 } 413 414 /* 415 * Calculate minimum allowed amount of main area LEBs. This is very 416 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we 417 * have just read from the superblock. 418 */ 419 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs; 420 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6; 421 422 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) { 423 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required", 424 c->leb_cnt, c->vi.size, min_leb_cnt); 425 goto failed; 426 } 427 428 if (c->max_leb_cnt < c->leb_cnt) { 429 ubifs_err(c, "max. LEB count %d less than LEB count %d", 430 c->max_leb_cnt, c->leb_cnt); 431 goto failed; 432 } 433 434 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) { 435 ubifs_err(c, "too few main LEBs count %d, must be at least %d", 436 c->main_lebs, UBIFS_MIN_MAIN_LEBS); 437 goto failed; 438 } 439 440 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS; 441 if (c->max_bud_bytes < max_bytes) { 442 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes", 443 c->max_bud_bytes, max_bytes); 444 goto failed; 445 } 446 447 max_bytes = (long long)c->leb_size * c->main_lebs; 448 if (c->max_bud_bytes > max_bytes) { 449 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area", 450 c->max_bud_bytes, max_bytes); 451 goto failed; 452 } 453 454 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 || 455 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) { 456 err = 9; 457 goto failed; 458 } 459 460 if (c->fanout < UBIFS_MIN_FANOUT || 461 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) { 462 err = 10; 463 goto failed; 464 } 465 466 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT && 467 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - 468 c->log_lebs - c->lpt_lebs - c->orph_lebs)) { 469 err = 11; 470 goto failed; 471 } 472 473 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs + 474 c->orph_lebs + c->main_lebs != c->leb_cnt) { 475 err = 12; 476 goto failed; 477 } 478 479 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) { 480 err = 13; 481 goto failed; 482 } 483 484 if (c->rp_size < 0 || max_bytes < c->rp_size) { 485 err = 14; 486 goto failed; 487 } 488 489 if (le32_to_cpu(sup->time_gran) > 1000000000 || 490 le32_to_cpu(sup->time_gran) < 1) { 491 err = 15; 492 goto failed; 493 } 494 495 if (!c->double_hash && c->fmt_version >= 5) { 496 err = 16; 497 goto failed; 498 } 499 500 if (c->encrypted && c->fmt_version < 5) { 501 err = 17; 502 goto failed; 503 } 504 505 return 0; 506 507failed: 508 ubifs_err(c, "bad superblock, error %d", err); 509 ubifs_dump_node(c, sup, ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size)); 510 return -EINVAL; 511} 512 513/** 514 * ubifs_read_sb_node - read superblock node. 515 * @c: UBIFS file-system description object 516 * 517 * This function returns a pointer to the superblock node or a negative error 518 * code. Note, the user of this function is responsible of kfree()'ing the 519 * returned superblock buffer. 520 */ 521static struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c) 522{ 523 struct ubifs_sb_node *sup; 524 int err; 525 526 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS); 527 if (!sup) 528 return ERR_PTR(-ENOMEM); 529 530 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ, 531 UBIFS_SB_LNUM, 0); 532 if (err) { 533 kfree(sup); 534 return ERR_PTR(err); 535 } 536 537 return sup; 538} 539 540static int authenticate_sb_node(struct ubifs_info *c, 541 const struct ubifs_sb_node *sup) 542{ 543 unsigned int sup_flags = le32_to_cpu(sup->flags); 544 u8 hmac_wkm[UBIFS_HMAC_ARR_SZ]; 545 int authenticated = !!(sup_flags & UBIFS_FLG_AUTHENTICATION); 546 int hash_algo; 547 int err; 548 549 if (c->authenticated && !authenticated) { 550 ubifs_err(c, "authenticated FS forced, but found FS without authentication"); 551 return -EINVAL; 552 } 553 554 if (!c->authenticated && authenticated) { 555 ubifs_err(c, "authenticated FS found, but no key given"); 556 return -EINVAL; 557 } 558 559 ubifs_msg(c, "Mounting in %sauthenticated mode", 560 c->authenticated ? "" : "un"); 561 562 if (!c->authenticated) 563 return 0; 564 565 if (!IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) 566 return -EOPNOTSUPP; 567 568 hash_algo = le16_to_cpu(sup->hash_algo); 569 if (hash_algo >= HASH_ALGO__LAST) { 570 ubifs_err(c, "superblock uses unknown hash algo %d", 571 hash_algo); 572 return -EINVAL; 573 } 574 575 if (strcmp(hash_algo_name[hash_algo], c->auth_hash_name)) { 576 ubifs_err(c, "This filesystem uses %s for hashing," 577 " but %s is specified", hash_algo_name[hash_algo], 578 c->auth_hash_name); 579 return -EINVAL; 580 } 581 582 /* 583 * The super block node can either be authenticated by a HMAC or 584 * by a signature in a ubifs_sig_node directly following the 585 * super block node to support offline image creation. 586 */ 587 if (ubifs_hmac_zero(c, sup->hmac)) { 588 err = ubifs_sb_verify_signature(c, sup); 589 } else { 590 err = ubifs_hmac_wkm(c, hmac_wkm); 591 if (err) 592 return err; 593 if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) { 594 ubifs_err(c, "provided key does not fit"); 595 return -ENOKEY; 596 } 597 err = ubifs_node_verify_hmac(c, sup, sizeof(*sup), 598 offsetof(struct ubifs_sb_node, 599 hmac)); 600 } 601 602 if (err) 603 ubifs_err(c, "Failed to authenticate superblock: %d", err); 604 605 return err; 606} 607 608/** 609 * ubifs_write_sb_node - write superblock node. 610 * @c: UBIFS file-system description object 611 * @sup: superblock node read with 'ubifs_read_sb_node()' 612 * 613 * This function returns %0 on success and a negative error code on failure. 614 */ 615int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) 616{ 617 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); 618 int err; 619 620 err = ubifs_prepare_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 621 offsetof(struct ubifs_sb_node, hmac), 1); 622 if (err) 623 return err; 624 625 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len); 626} 627 628/** 629 * ubifs_read_superblock - read superblock. 630 * @c: UBIFS file-system description object 631 * 632 * This function finds, reads and checks the superblock. If an empty UBI volume 633 * is being mounted, this function creates default superblock. Returns zero in 634 * case of success, and a negative error code in case of failure. 635 */ 636int ubifs_read_superblock(struct ubifs_info *c) 637{ 638 int err, sup_flags; 639 struct ubifs_sb_node *sup; 640 641 if (c->empty) { 642 err = create_default_filesystem(c); 643 if (err) 644 return err; 645 } 646 647 sup = ubifs_read_sb_node(c); 648 if (IS_ERR(sup)) 649 return PTR_ERR(sup); 650 651 c->sup_node = sup; 652 653 c->fmt_version = le32_to_cpu(sup->fmt_version); 654 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); 655 656 /* 657 * The software supports all previous versions but not future versions, 658 * due to the unavailability of time-travelling equipment. 659 */ 660 if (c->fmt_version > UBIFS_FORMAT_VERSION) { 661 ubifs_assert(c, !c->ro_media || c->ro_mount); 662 if (!c->ro_mount || 663 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { 664 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d", 665 c->fmt_version, c->ro_compat_version, 666 UBIFS_FORMAT_VERSION, 667 UBIFS_RO_COMPAT_VERSION); 668 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { 669 ubifs_msg(c, "only R/O mounting is possible"); 670 err = -EROFS; 671 } else 672 err = -EINVAL; 673 goto out; 674 } 675 676 /* 677 * The FS is mounted R/O, and the media format is 678 * R/O-compatible with the UBIFS implementation, so we can 679 * mount. 680 */ 681 c->rw_incompat = 1; 682 } 683 684 if (c->fmt_version < 3) { 685 ubifs_err(c, "on-flash format version %d is not supported", 686 c->fmt_version); 687 err = -EINVAL; 688 goto out; 689 } 690 691 switch (sup->key_hash) { 692 case UBIFS_KEY_HASH_R5: 693 c->key_hash = key_r5_hash; 694 c->key_hash_type = UBIFS_KEY_HASH_R5; 695 break; 696 697 case UBIFS_KEY_HASH_TEST: 698 c->key_hash = key_test_hash; 699 c->key_hash_type = UBIFS_KEY_HASH_TEST; 700 break; 701 } 702 703 c->key_fmt = sup->key_fmt; 704 705 switch (c->key_fmt) { 706 case UBIFS_SIMPLE_KEY_FMT: 707 c->key_len = UBIFS_SK_LEN; 708 break; 709 default: 710 ubifs_err(c, "unsupported key format"); 711 err = -EINVAL; 712 goto out; 713 } 714 715 c->leb_cnt = le32_to_cpu(sup->leb_cnt); 716 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); 717 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); 718 c->log_lebs = le32_to_cpu(sup->log_lebs); 719 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); 720 c->orph_lebs = le32_to_cpu(sup->orph_lebs); 721 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; 722 c->fanout = le32_to_cpu(sup->fanout); 723 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); 724 c->rp_size = le64_to_cpu(sup->rp_size); 725 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid)); 726 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid)); 727 sup_flags = le32_to_cpu(sup->flags); 728 if (!c->mount_opts.override_compr) 729 c->default_compr = le16_to_cpu(sup->default_compr); 730 731 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); 732 memcpy(&c->uuid, &sup->uuid, 16); 733 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); 734 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); 735 c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); 736 c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); 737 738 err = authenticate_sb_node(c, sup); 739 if (err) 740 goto out; 741 742 if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { 743 ubifs_err(c, "Unknown feature flags found: %#x", 744 sup_flags & ~UBIFS_FLG_MASK); 745 err = -EINVAL; 746 goto out; 747 } 748 749 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) { 750 ubifs_err(c, "file system contains encrypted files but UBIFS" 751 " was built without crypto support."); 752 err = -EINVAL; 753 goto out; 754 } 755 756 /* Automatically increase file system size to the maximum size */ 757 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { 758 int old_leb_cnt = c->leb_cnt; 759 760 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); 761 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 762 763 c->superblock_need_write = 1; 764 765 dbg_mnt("Auto resizing from %d LEBs to %d LEBs", 766 old_leb_cnt, c->leb_cnt); 767 } 768 769 c->log_bytes = (long long)c->log_lebs * c->leb_size; 770 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; 771 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; 772 c->lpt_last = c->lpt_first + c->lpt_lebs - 1; 773 c->orph_first = c->lpt_last + 1; 774 c->orph_last = c->orph_first + c->orph_lebs - 1; 775 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; 776 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; 777 c->main_first = c->leb_cnt - c->main_lebs; 778 779 err = validate_sb(c, sup); 780out: 781 return err; 782} 783 784/** 785 * fixup_leb - fixup/unmap an LEB containing free space. 786 * @c: UBIFS file-system description object 787 * @lnum: the LEB number to fix up 788 * @len: number of used bytes in LEB (starting at offset 0) 789 * 790 * This function reads the contents of the given LEB number @lnum, then fixes 791 * it up, so that empty min. I/O units in the end of LEB are actually erased on 792 * flash (rather than being just all-0xff real data). If the LEB is completely 793 * empty, it is simply unmapped. 794 */ 795static int fixup_leb(struct ubifs_info *c, int lnum, int len) 796{ 797 int err; 798 799 ubifs_assert(c, len >= 0); 800 ubifs_assert(c, len % c->min_io_size == 0); 801 ubifs_assert(c, len < c->leb_size); 802 803 if (len == 0) { 804 dbg_mnt("unmap empty LEB %d", lnum); 805 return ubifs_leb_unmap(c, lnum); 806 } 807 808 dbg_mnt("fixup LEB %d, data len %d", lnum, len); 809 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1); 810 if (err) 811 return err; 812 813 return ubifs_leb_change(c, lnum, c->sbuf, len); 814} 815 816/** 817 * fixup_free_space - find & remap all LEBs containing free space. 818 * @c: UBIFS file-system description object 819 * 820 * This function walks through all LEBs in the filesystem and fiexes up those 821 * containing free/empty space. 822 */ 823static int fixup_free_space(struct ubifs_info *c) 824{ 825 int lnum, err = 0; 826 struct ubifs_lprops *lprops; 827 828 ubifs_get_lprops(c); 829 830 /* Fixup LEBs in the master area */ 831 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) { 832 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz); 833 if (err) 834 goto out; 835 } 836 837 /* Unmap unused log LEBs */ 838 lnum = ubifs_next_log_lnum(c, c->lhead_lnum); 839 while (lnum != c->ltail_lnum) { 840 err = fixup_leb(c, lnum, 0); 841 if (err) 842 goto out; 843 lnum = ubifs_next_log_lnum(c, lnum); 844 } 845 846 /* 847 * Fixup the log head which contains the only a CS node at the 848 * beginning. 849 */ 850 err = fixup_leb(c, c->lhead_lnum, 851 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size)); 852 if (err) 853 goto out; 854 855 /* Fixup LEBs in the LPT area */ 856 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { 857 int free = c->ltab[lnum - c->lpt_first].free; 858 859 if (free > 0) { 860 err = fixup_leb(c, lnum, c->leb_size - free); 861 if (err) 862 goto out; 863 } 864 } 865 866 /* Unmap LEBs in the orphans area */ 867 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { 868 err = fixup_leb(c, lnum, 0); 869 if (err) 870 goto out; 871 } 872 873 /* Fixup LEBs in the main area */ 874 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { 875 lprops = ubifs_lpt_lookup(c, lnum); 876 if (IS_ERR(lprops)) { 877 err = PTR_ERR(lprops); 878 goto out; 879 } 880 881 if (lprops->free > 0) { 882 err = fixup_leb(c, lnum, c->leb_size - lprops->free); 883 if (err) 884 goto out; 885 } 886 } 887 888out: 889 ubifs_release_lprops(c); 890 return err; 891} 892 893/** 894 * ubifs_fixup_free_space - find & fix all LEBs with free space. 895 * @c: UBIFS file-system description object 896 * 897 * This function fixes up LEBs containing free space on first mount, if the 898 * appropriate flag was set when the FS was created. Each LEB with one or more 899 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure 900 * the free space is actually erased. E.g., this is necessary for some NAND 901 * chips, since the free space may have been programmed like real "0xff" data 902 * (generating a non-0xff ECC), causing future writes to the not-really-erased 903 * NAND pages to behave badly. After the space is fixed up, the superblock flag 904 * is cleared, so that this is skipped for all future mounts. 905 */ 906int ubifs_fixup_free_space(struct ubifs_info *c) 907{ 908 int err; 909 struct ubifs_sb_node *sup = c->sup_node; 910 911 ubifs_assert(c, c->space_fixup); 912 ubifs_assert(c, !c->ro_mount); 913 914 ubifs_msg(c, "start fixing up free space"); 915 916 err = fixup_free_space(c); 917 if (err) 918 return err; 919 920 /* Free-space fixup is no longer required */ 921 c->space_fixup = 0; 922 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); 923 924 c->superblock_need_write = 1; 925 926 ubifs_msg(c, "free space fixup complete"); 927 return err; 928} 929 930int ubifs_enable_encryption(struct ubifs_info *c) 931{ 932 int err; 933 struct ubifs_sb_node *sup = c->sup_node; 934 935 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) 936 return -EOPNOTSUPP; 937 938 if (c->encrypted) 939 return 0; 940 941 if (c->ro_mount || c->ro_media) 942 return -EROFS; 943 944 if (c->fmt_version < 5) { 945 ubifs_err(c, "on-flash format version 5 is needed for encryption"); 946 return -EINVAL; 947 } 948 949 sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION); 950 951 err = ubifs_write_sb_node(c, sup); 952 if (!err) 953 c->encrypted = 1; 954 955 return err; 956} 957