1 /* 2 * This file is part of UBIFS. 3 * 4 * Copyright (C) 2006-2008 Nokia Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published by 8 * the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along with 16 * this program; if not, write to the Free Software Foundation, Inc., 51 17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 18 * 19 * Authors: Artem Bityutskiy (Битюцкий Артём) 20 * Adrian Hunter 21 */ 22 23 /* 24 * This file implements UBIFS superblock. The superblock is stored at the first 25 * LEB of the volume and is never changed by UBIFS. Only user-space tools may 26 * change it. The superblock node mostly contains geometry information. 27 */ 28 29 #include "ubifs.h" 30 #include <linux/slab.h> 31 #include <linux/math64.h> 32 #include <linux/uuid.h> 33 34 /* 35 * Default journal size in logical eraseblocks as a percent of total 36 * flash size. 37 */ 38 #define DEFAULT_JNL_PERCENT 5 39 40 /* Default maximum journal size in bytes */ 41 #define DEFAULT_MAX_JNL (32*1024*1024) 42 43 /* Default indexing tree fanout */ 44 #define DEFAULT_FANOUT 8 45 46 /* Default number of data journal heads */ 47 #define DEFAULT_JHEADS_CNT 1 48 49 /* Default positions of different LEBs in the main area */ 50 #define DEFAULT_IDX_LEB 0 51 #define DEFAULT_DATA_LEB 1 52 #define DEFAULT_GC_LEB 2 53 54 /* Default number of LEB numbers in LPT's save table */ 55 #define DEFAULT_LSAVE_CNT 256 56 57 /* Default reserved pool size as a percent of maximum free space */ 58 #define DEFAULT_RP_PERCENT 5 59 60 /* The default maximum size of reserved pool in bytes */ 61 #define DEFAULT_MAX_RP_SIZE (5*1024*1024) 62 63 /* Default time granularity in nanoseconds */ 64 #define DEFAULT_TIME_GRAN 1000000000 65 66 /** 67 * create_default_filesystem - format empty UBI volume. 68 * @c: UBIFS file-system description object 69 * 70 * This function creates default empty file-system. Returns zero in case of 71 * success and a negative error code in case of failure. 72 */ 73 static int create_default_filesystem(struct ubifs_info *c) 74 { 75 struct ubifs_sb_node *sup; 76 struct ubifs_mst_node *mst; 77 struct ubifs_idx_node *idx; 78 struct ubifs_branch *br; 79 struct ubifs_ino_node *ino; 80 struct ubifs_cs_node *cs; 81 union ubifs_key key; 82 int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first; 83 int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0; 84 int min_leb_cnt = UBIFS_MIN_LEB_CNT; 85 int idx_node_size; 86 long long tmp64, main_bytes; 87 __le64 tmp_le64; 88 __le32 tmp_le32; 89 struct timespec64 ts; 90 u8 hash[UBIFS_HASH_ARR_SZ]; 91 u8 hash_lpt[UBIFS_HASH_ARR_SZ]; 92 93 /* Some functions called from here depend on the @c->key_len filed */ 94 c->key_len = UBIFS_SK_LEN; 95 96 /* 97 * First of all, we have to calculate default file-system geometry - 98 * log size, journal size, etc. 99 */ 100 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT) 101 /* We can first multiply then divide and have no overflow */ 102 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100; 103 else 104 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT; 105 106 if (jnl_lebs < UBIFS_MIN_JNL_LEBS) 107 jnl_lebs = UBIFS_MIN_JNL_LEBS; 108 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL) 109 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size; 110 111 /* 112 * The log should be large enough to fit reference nodes for all bud 113 * LEBs. Because buds do not have to start from the beginning of LEBs 114 * (half of the LEB may contain committed data), the log should 115 * generally be larger, make it twice as large. 116 */ 117 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1; 118 log_lebs = tmp / c->leb_size; 119 /* Plus one LEB reserved for commit */ 120 log_lebs += 1; 121 if (c->leb_cnt - min_leb_cnt > 8) { 122 /* And some extra space to allow writes while committing */ 123 log_lebs += 1; 124 min_leb_cnt += 1; 125 } 126 127 max_buds = jnl_lebs - log_lebs; 128 if (max_buds < UBIFS_MIN_BUD_LEBS) 129 max_buds = UBIFS_MIN_BUD_LEBS; 130 131 /* 132 * Orphan nodes are stored in a separate area. One node can store a lot 133 * of orphan inode numbers, but when new orphan comes we just add a new 134 * orphan node. At some point the nodes are consolidated into one 135 * orphan node. 136 */ 137 orph_lebs = UBIFS_MIN_ORPH_LEBS; 138 if (c->leb_cnt - min_leb_cnt > 1) 139 /* 140 * For debugging purposes it is better to have at least 2 141 * orphan LEBs, because the orphan subsystem would need to do 142 * consolidations and would be stressed more. 143 */ 144 orph_lebs += 1; 145 146 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs; 147 main_lebs -= orph_lebs; 148 149 lpt_first = UBIFS_LOG_LNUM + log_lebs; 150 c->lsave_cnt = DEFAULT_LSAVE_CNT; 151 c->max_leb_cnt = c->leb_cnt; 152 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs, 153 &big_lpt, hash_lpt); 154 if (err) 155 return err; 156 157 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first, 158 lpt_first + lpt_lebs - 1); 159 160 main_first = c->leb_cnt - main_lebs; 161 162 sup = kzalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_KERNEL); 163 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); 164 idx_node_size = ubifs_idx_node_sz(c, 1); 165 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL); 166 ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL); 167 cs = kzalloc(ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size), GFP_KERNEL); 168 169 if (!sup || !mst || !idx || !ino || !cs) { 170 err = -ENOMEM; 171 goto out; 172 } 173 174 /* Create default superblock */ 175 176 tmp64 = (long long)max_buds * c->leb_size; 177 if (big_lpt) 178 sup_flags |= UBIFS_FLG_BIGLPT; 179 sup_flags |= UBIFS_FLG_DOUBLE_HASH; 180 181 if (ubifs_authenticated(c)) { 182 sup_flags |= UBIFS_FLG_AUTHENTICATION; 183 sup->hash_algo = cpu_to_le16(c->auth_hash_algo); 184 err = ubifs_hmac_wkm(c, sup->hmac_wkm); 185 if (err) 186 goto out; 187 } else { 188 sup->hash_algo = 0xffff; 189 } 190 191 sup->ch.node_type = UBIFS_SB_NODE; 192 sup->key_hash = UBIFS_KEY_HASH_R5; 193 sup->flags = cpu_to_le32(sup_flags); 194 sup->min_io_size = cpu_to_le32(c->min_io_size); 195 sup->leb_size = cpu_to_le32(c->leb_size); 196 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 197 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt); 198 sup->max_bud_bytes = cpu_to_le64(tmp64); 199 sup->log_lebs = cpu_to_le32(log_lebs); 200 sup->lpt_lebs = cpu_to_le32(lpt_lebs); 201 sup->orph_lebs = cpu_to_le32(orph_lebs); 202 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT); 203 sup->fanout = cpu_to_le32(DEFAULT_FANOUT); 204 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt); 205 sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION); 206 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN); 207 if (c->mount_opts.override_compr) 208 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type); 209 else 210 sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO); 211 212 generate_random_uuid(sup->uuid); 213 214 main_bytes = (long long)main_lebs * c->leb_size; 215 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100); 216 if (tmp64 > DEFAULT_MAX_RP_SIZE) 217 tmp64 = DEFAULT_MAX_RP_SIZE; 218 sup->rp_size = cpu_to_le64(tmp64); 219 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION); 220 221 dbg_gen("default superblock created at LEB 0:0"); 222 223 /* Create default master node */ 224 225 mst->ch.node_type = UBIFS_MST_NODE; 226 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM); 227 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO); 228 mst->cmt_no = 0; 229 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); 230 mst->root_offs = 0; 231 tmp = ubifs_idx_node_sz(c, 1); 232 mst->root_len = cpu_to_le32(tmp); 233 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB); 234 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); 235 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size)); 236 mst->index_size = cpu_to_le64(ALIGN(tmp, 8)); 237 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum); 238 mst->lpt_offs = cpu_to_le32(c->lpt_offs); 239 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum); 240 mst->nhead_offs = cpu_to_le32(c->nhead_offs); 241 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum); 242 mst->ltab_offs = cpu_to_le32(c->ltab_offs); 243 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum); 244 mst->lsave_offs = cpu_to_le32(c->lsave_offs); 245 mst->lscan_lnum = cpu_to_le32(main_first); 246 mst->empty_lebs = cpu_to_le32(main_lebs - 2); 247 mst->idx_lebs = cpu_to_le32(1); 248 mst->leb_cnt = cpu_to_le32(c->leb_cnt); 249 ubifs_copy_hash(c, hash_lpt, mst->hash_lpt); 250 251 /* Calculate lprops statistics */ 252 tmp64 = main_bytes; 253 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); 254 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); 255 mst->total_free = cpu_to_le64(tmp64); 256 257 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); 258 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) - 259 UBIFS_INO_NODE_SZ; 260 tmp64 += ino_waste; 261 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8); 262 mst->total_dirty = cpu_to_le64(tmp64); 263 264 /* The indexing LEB does not contribute to dark space */ 265 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm); 266 mst->total_dark = cpu_to_le64(tmp64); 267 268 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); 269 270 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM); 271 272 /* Create the root indexing node */ 273 274 c->key_fmt = UBIFS_SIMPLE_KEY_FMT; 275 c->key_hash = key_r5_hash; 276 277 idx->ch.node_type = UBIFS_IDX_NODE; 278 idx->child_cnt = cpu_to_le16(1); 279 ino_key_init(c, &key, UBIFS_ROOT_INO); 280 br = ubifs_idx_branch(c, idx, 0); 281 key_write_idx(c, &key, &br->key); 282 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB); 283 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ); 284 285 dbg_gen("default root indexing node created LEB %d:0", 286 main_first + DEFAULT_IDX_LEB); 287 288 /* Create default root inode */ 289 290 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO); 291 ino->ch.node_type = UBIFS_INO_NODE; 292 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); 293 ino->nlink = cpu_to_le32(2); 294 295 ktime_get_real_ts64(&ts); 296 ts = timespec64_trunc(ts, DEFAULT_TIME_GRAN); 297 tmp_le64 = cpu_to_le64(ts.tv_sec); 298 ino->atime_sec = tmp_le64; 299 ino->ctime_sec = tmp_le64; 300 ino->mtime_sec = tmp_le64; 301 tmp_le32 = cpu_to_le32(ts.tv_nsec); 302 ino->atime_nsec = tmp_le32; 303 ino->ctime_nsec = tmp_le32; 304 ino->mtime_nsec = tmp_le32; 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; 359 out: 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 */ 379 static 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; 506 507 failed: 508 ubifs_err(c, "bad superblock, error %d", err); 509 ubifs_dump_node(c, sup); 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 */ 521 static 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 } 539 540 static 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 err = ubifs_hmac_wkm(c, hmac_wkm); 583 if (err) 584 return err; 585 586 if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) { 587 ubifs_err(c, "provided key does not fit"); 588 return -ENOKEY; 589 } 590 591 err = ubifs_node_verify_hmac(c, sup, sizeof(*sup), 592 offsetof(struct ubifs_sb_node, hmac)); 593 if (err) 594 ubifs_err(c, "Failed to authenticate superblock: %d", err); 595 596 return err; 597 } 598 599 /** 600 * ubifs_write_sb_node - write superblock node. 601 * @c: UBIFS file-system description object 602 * @sup: superblock node read with 'ubifs_read_sb_node()' 603 * 604 * This function returns %0 on success and a negative error code on failure. 605 */ 606 int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) 607 { 608 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); 609 int err; 610 611 err = ubifs_prepare_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 612 offsetof(struct ubifs_sb_node, hmac), 1); 613 if (err) 614 return err; 615 616 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len); 617 } 618 619 /** 620 * ubifs_read_superblock - read superblock. 621 * @c: UBIFS file-system description object 622 * 623 * This function finds, reads and checks the superblock. If an empty UBI volume 624 * is being mounted, this function creates default superblock. Returns zero in 625 * case of success, and a negative error code in case of failure. 626 */ 627 int ubifs_read_superblock(struct ubifs_info *c) 628 { 629 int err, sup_flags; 630 struct ubifs_sb_node *sup; 631 632 if (c->empty) { 633 err = create_default_filesystem(c); 634 if (err) 635 return err; 636 } 637 638 sup = ubifs_read_sb_node(c); 639 if (IS_ERR(sup)) 640 return PTR_ERR(sup); 641 642 c->sup_node = sup; 643 644 c->fmt_version = le32_to_cpu(sup->fmt_version); 645 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); 646 647 /* 648 * The software supports all previous versions but not future versions, 649 * due to the unavailability of time-travelling equipment. 650 */ 651 if (c->fmt_version > UBIFS_FORMAT_VERSION) { 652 ubifs_assert(c, !c->ro_media || c->ro_mount); 653 if (!c->ro_mount || 654 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { 655 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d", 656 c->fmt_version, c->ro_compat_version, 657 UBIFS_FORMAT_VERSION, 658 UBIFS_RO_COMPAT_VERSION); 659 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { 660 ubifs_msg(c, "only R/O mounting is possible"); 661 err = -EROFS; 662 } else 663 err = -EINVAL; 664 goto out; 665 } 666 667 /* 668 * The FS is mounted R/O, and the media format is 669 * R/O-compatible with the UBIFS implementation, so we can 670 * mount. 671 */ 672 c->rw_incompat = 1; 673 } 674 675 if (c->fmt_version < 3) { 676 ubifs_err(c, "on-flash format version %d is not supported", 677 c->fmt_version); 678 err = -EINVAL; 679 goto out; 680 } 681 682 switch (sup->key_hash) { 683 case UBIFS_KEY_HASH_R5: 684 c->key_hash = key_r5_hash; 685 c->key_hash_type = UBIFS_KEY_HASH_R5; 686 break; 687 688 case UBIFS_KEY_HASH_TEST: 689 c->key_hash = key_test_hash; 690 c->key_hash_type = UBIFS_KEY_HASH_TEST; 691 break; 692 } 693 694 c->key_fmt = sup->key_fmt; 695 696 switch (c->key_fmt) { 697 case UBIFS_SIMPLE_KEY_FMT: 698 c->key_len = UBIFS_SK_LEN; 699 break; 700 default: 701 ubifs_err(c, "unsupported key format"); 702 err = -EINVAL; 703 goto out; 704 } 705 706 c->leb_cnt = le32_to_cpu(sup->leb_cnt); 707 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); 708 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); 709 c->log_lebs = le32_to_cpu(sup->log_lebs); 710 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); 711 c->orph_lebs = le32_to_cpu(sup->orph_lebs); 712 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; 713 c->fanout = le32_to_cpu(sup->fanout); 714 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); 715 c->rp_size = le64_to_cpu(sup->rp_size); 716 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid)); 717 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid)); 718 sup_flags = le32_to_cpu(sup->flags); 719 if (!c->mount_opts.override_compr) 720 c->default_compr = le16_to_cpu(sup->default_compr); 721 722 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); 723 memcpy(&c->uuid, &sup->uuid, 16); 724 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); 725 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); 726 c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); 727 c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); 728 729 err = authenticate_sb_node(c, sup); 730 if (err) 731 goto out; 732 733 if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { 734 ubifs_err(c, "Unknown feature flags found: %#x", 735 sup_flags & ~UBIFS_FLG_MASK); 736 err = -EINVAL; 737 goto out; 738 } 739 740 #ifndef CONFIG_UBIFS_FS_ENCRYPTION 741 if (c->encrypted) { 742 ubifs_err(c, "file system contains encrypted files but UBIFS" 743 " was built without crypto support."); 744 err = -EINVAL; 745 goto out; 746 } 747 #endif 748 749 /* Automatically increase file system size to the maximum size */ 750 c->old_leb_cnt = c->leb_cnt; 751 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { 752 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); 753 if (c->ro_mount) 754 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs", 755 c->old_leb_cnt, c->leb_cnt); 756 else { 757 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs", 758 c->old_leb_cnt, c->leb_cnt); 759 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 760 err = ubifs_write_sb_node(c, sup); 761 if (err) 762 goto out; 763 c->old_leb_cnt = c->leb_cnt; 764 } 765 } 766 767 c->log_bytes = (long long)c->log_lebs * c->leb_size; 768 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; 769 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; 770 c->lpt_last = c->lpt_first + c->lpt_lebs - 1; 771 c->orph_first = c->lpt_last + 1; 772 c->orph_last = c->orph_first + c->orph_lebs - 1; 773 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; 774 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; 775 c->main_first = c->leb_cnt - c->main_lebs; 776 777 err = validate_sb(c, sup); 778 out: 779 return err; 780 } 781 782 /** 783 * fixup_leb - fixup/unmap an LEB containing free space. 784 * @c: UBIFS file-system description object 785 * @lnum: the LEB number to fix up 786 * @len: number of used bytes in LEB (starting at offset 0) 787 * 788 * This function reads the contents of the given LEB number @lnum, then fixes 789 * it up, so that empty min. I/O units in the end of LEB are actually erased on 790 * flash (rather than being just all-0xff real data). If the LEB is completely 791 * empty, it is simply unmapped. 792 */ 793 static int fixup_leb(struct ubifs_info *c, int lnum, int len) 794 { 795 int err; 796 797 ubifs_assert(c, len >= 0); 798 ubifs_assert(c, len % c->min_io_size == 0); 799 ubifs_assert(c, len < c->leb_size); 800 801 if (len == 0) { 802 dbg_mnt("unmap empty LEB %d", lnum); 803 return ubifs_leb_unmap(c, lnum); 804 } 805 806 dbg_mnt("fixup LEB %d, data len %d", lnum, len); 807 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1); 808 if (err) 809 return err; 810 811 return ubifs_leb_change(c, lnum, c->sbuf, len); 812 } 813 814 /** 815 * fixup_free_space - find & remap all LEBs containing free space. 816 * @c: UBIFS file-system description object 817 * 818 * This function walks through all LEBs in the filesystem and fiexes up those 819 * containing free/empty space. 820 */ 821 static int fixup_free_space(struct ubifs_info *c) 822 { 823 int lnum, err = 0; 824 struct ubifs_lprops *lprops; 825 826 ubifs_get_lprops(c); 827 828 /* Fixup LEBs in the master area */ 829 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) { 830 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz); 831 if (err) 832 goto out; 833 } 834 835 /* Unmap unused log LEBs */ 836 lnum = ubifs_next_log_lnum(c, c->lhead_lnum); 837 while (lnum != c->ltail_lnum) { 838 err = fixup_leb(c, lnum, 0); 839 if (err) 840 goto out; 841 lnum = ubifs_next_log_lnum(c, lnum); 842 } 843 844 /* 845 * Fixup the log head which contains the only a CS node at the 846 * beginning. 847 */ 848 err = fixup_leb(c, c->lhead_lnum, 849 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size)); 850 if (err) 851 goto out; 852 853 /* Fixup LEBs in the LPT area */ 854 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { 855 int free = c->ltab[lnum - c->lpt_first].free; 856 857 if (free > 0) { 858 err = fixup_leb(c, lnum, c->leb_size - free); 859 if (err) 860 goto out; 861 } 862 } 863 864 /* Unmap LEBs in the orphans area */ 865 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { 866 err = fixup_leb(c, lnum, 0); 867 if (err) 868 goto out; 869 } 870 871 /* Fixup LEBs in the main area */ 872 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { 873 lprops = ubifs_lpt_lookup(c, lnum); 874 if (IS_ERR(lprops)) { 875 err = PTR_ERR(lprops); 876 goto out; 877 } 878 879 if (lprops->free > 0) { 880 err = fixup_leb(c, lnum, c->leb_size - lprops->free); 881 if (err) 882 goto out; 883 } 884 } 885 886 out: 887 ubifs_release_lprops(c); 888 return err; 889 } 890 891 /** 892 * ubifs_fixup_free_space - find & fix all LEBs with free space. 893 * @c: UBIFS file-system description object 894 * 895 * This function fixes up LEBs containing free space on first mount, if the 896 * appropriate flag was set when the FS was created. Each LEB with one or more 897 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure 898 * the free space is actually erased. E.g., this is necessary for some NAND 899 * chips, since the free space may have been programmed like real "0xff" data 900 * (generating a non-0xff ECC), causing future writes to the not-really-erased 901 * NAND pages to behave badly. After the space is fixed up, the superblock flag 902 * is cleared, so that this is skipped for all future mounts. 903 */ 904 int ubifs_fixup_free_space(struct ubifs_info *c) 905 { 906 int err; 907 struct ubifs_sb_node *sup = c->sup_node; 908 909 ubifs_assert(c, c->space_fixup); 910 ubifs_assert(c, !c->ro_mount); 911 912 ubifs_msg(c, "start fixing up free space"); 913 914 err = fixup_free_space(c); 915 if (err) 916 return err; 917 918 /* Free-space fixup is no longer required */ 919 c->space_fixup = 0; 920 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); 921 922 err = ubifs_write_sb_node(c, sup); 923 if (err) 924 return err; 925 926 ubifs_msg(c, "free space fixup complete"); 927 return err; 928 } 929 930 int ubifs_enable_encryption(struct ubifs_info *c) 931 { 932 int err; 933 struct ubifs_sb_node *sup = c->sup_node; 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