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 long long tmp64, main_bytes; 86 __le64 tmp_le64; 87 __le32 tmp_le32; 88 struct timespec ts; 89 90 /* Some functions called from here depend on the @c->key_len filed */ 91 c->key_len = UBIFS_SK_LEN; 92 93 /* 94 * First of all, we have to calculate default file-system geometry - 95 * log size, journal size, etc. 96 */ 97 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT) 98 /* We can first multiply then divide and have no overflow */ 99 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100; 100 else 101 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT; 102 103 if (jnl_lebs < UBIFS_MIN_JNL_LEBS) 104 jnl_lebs = UBIFS_MIN_JNL_LEBS; 105 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL) 106 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size; 107 108 /* 109 * The log should be large enough to fit reference nodes for all bud 110 * LEBs. Because buds do not have to start from the beginning of LEBs 111 * (half of the LEB may contain committed data), the log should 112 * generally be larger, make it twice as large. 113 */ 114 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1; 115 log_lebs = tmp / c->leb_size; 116 /* Plus one LEB reserved for commit */ 117 log_lebs += 1; 118 if (c->leb_cnt - min_leb_cnt > 8) { 119 /* And some extra space to allow writes while committing */ 120 log_lebs += 1; 121 min_leb_cnt += 1; 122 } 123 124 max_buds = jnl_lebs - log_lebs; 125 if (max_buds < UBIFS_MIN_BUD_LEBS) 126 max_buds = UBIFS_MIN_BUD_LEBS; 127 128 /* 129 * Orphan nodes are stored in a separate area. One node can store a lot 130 * of orphan inode numbers, but when new orphan comes we just add a new 131 * orphan node. At some point the nodes are consolidated into one 132 * orphan node. 133 */ 134 orph_lebs = UBIFS_MIN_ORPH_LEBS; 135 if (c->leb_cnt - min_leb_cnt > 1) 136 /* 137 * For debugging purposes it is better to have at least 2 138 * orphan LEBs, because the orphan subsystem would need to do 139 * consolidations and would be stressed more. 140 */ 141 orph_lebs += 1; 142 143 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs; 144 main_lebs -= orph_lebs; 145 146 lpt_first = UBIFS_LOG_LNUM + log_lebs; 147 c->lsave_cnt = DEFAULT_LSAVE_CNT; 148 c->max_leb_cnt = c->leb_cnt; 149 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs, 150 &big_lpt); 151 if (err) 152 return err; 153 154 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first, 155 lpt_first + lpt_lebs - 1); 156 157 main_first = c->leb_cnt - main_lebs; 158 159 /* Create default superblock */ 160 tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); 161 sup = kzalloc(tmp, GFP_KERNEL); 162 if (!sup) 163 return -ENOMEM; 164 165 tmp64 = (long long)max_buds * c->leb_size; 166 if (big_lpt) 167 sup_flags |= UBIFS_FLG_BIGLPT; 168 sup_flags |= UBIFS_FLG_DOUBLE_HASH; 169 170 sup->ch.node_type = UBIFS_SB_NODE; 171 sup->key_hash = UBIFS_KEY_HASH_R5; 172 sup->flags = cpu_to_le32(sup_flags); 173 sup->min_io_size = cpu_to_le32(c->min_io_size); 174 sup->leb_size = cpu_to_le32(c->leb_size); 175 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 176 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt); 177 sup->max_bud_bytes = cpu_to_le64(tmp64); 178 sup->log_lebs = cpu_to_le32(log_lebs); 179 sup->lpt_lebs = cpu_to_le32(lpt_lebs); 180 sup->orph_lebs = cpu_to_le32(orph_lebs); 181 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT); 182 sup->fanout = cpu_to_le32(DEFAULT_FANOUT); 183 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt); 184 sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION); 185 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN); 186 if (c->mount_opts.override_compr) 187 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type); 188 else 189 sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO); 190 191 generate_random_uuid(sup->uuid); 192 193 main_bytes = (long long)main_lebs * c->leb_size; 194 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100); 195 if (tmp64 > DEFAULT_MAX_RP_SIZE) 196 tmp64 = DEFAULT_MAX_RP_SIZE; 197 sup->rp_size = cpu_to_le64(tmp64); 198 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION); 199 200 err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0); 201 kfree(sup); 202 if (err) 203 return err; 204 205 dbg_gen("default superblock created at LEB 0:0"); 206 207 /* Create default master node */ 208 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); 209 if (!mst) 210 return -ENOMEM; 211 212 mst->ch.node_type = UBIFS_MST_NODE; 213 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM); 214 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO); 215 mst->cmt_no = 0; 216 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); 217 mst->root_offs = 0; 218 tmp = ubifs_idx_node_sz(c, 1); 219 mst->root_len = cpu_to_le32(tmp); 220 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB); 221 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); 222 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size)); 223 mst->index_size = cpu_to_le64(ALIGN(tmp, 8)); 224 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum); 225 mst->lpt_offs = cpu_to_le32(c->lpt_offs); 226 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum); 227 mst->nhead_offs = cpu_to_le32(c->nhead_offs); 228 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum); 229 mst->ltab_offs = cpu_to_le32(c->ltab_offs); 230 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum); 231 mst->lsave_offs = cpu_to_le32(c->lsave_offs); 232 mst->lscan_lnum = cpu_to_le32(main_first); 233 mst->empty_lebs = cpu_to_le32(main_lebs - 2); 234 mst->idx_lebs = cpu_to_le32(1); 235 mst->leb_cnt = cpu_to_le32(c->leb_cnt); 236 237 /* Calculate lprops statistics */ 238 tmp64 = main_bytes; 239 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); 240 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); 241 mst->total_free = cpu_to_le64(tmp64); 242 243 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); 244 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) - 245 UBIFS_INO_NODE_SZ; 246 tmp64 += ino_waste; 247 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8); 248 mst->total_dirty = cpu_to_le64(tmp64); 249 250 /* The indexing LEB does not contribute to dark space */ 251 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm); 252 mst->total_dark = cpu_to_le64(tmp64); 253 254 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); 255 256 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0); 257 if (err) { 258 kfree(mst); 259 return err; 260 } 261 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 262 0); 263 kfree(mst); 264 if (err) 265 return err; 266 267 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM); 268 269 /* Create the root indexing node */ 270 tmp = ubifs_idx_node_sz(c, 1); 271 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL); 272 if (!idx) 273 return -ENOMEM; 274 275 c->key_fmt = UBIFS_SIMPLE_KEY_FMT; 276 c->key_hash = key_r5_hash; 277 278 idx->ch.node_type = UBIFS_IDX_NODE; 279 idx->child_cnt = cpu_to_le16(1); 280 ino_key_init(c, &key, UBIFS_ROOT_INO); 281 br = ubifs_idx_branch(c, idx, 0); 282 key_write_idx(c, &key, &br->key); 283 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB); 284 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ); 285 err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0); 286 kfree(idx); 287 if (err) 288 return err; 289 290 dbg_gen("default root indexing node created LEB %d:0", 291 main_first + DEFAULT_IDX_LEB); 292 293 /* Create default root inode */ 294 tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); 295 ino = kzalloc(tmp, GFP_KERNEL); 296 if (!ino) 297 return -ENOMEM; 298 299 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO); 300 ino->ch.node_type = UBIFS_INO_NODE; 301 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); 302 ino->nlink = cpu_to_le32(2); 303 304 ktime_get_real_ts(&ts); 305 ts = timespec_trunc(ts, DEFAULT_TIME_GRAN); 306 tmp_le64 = cpu_to_le64(ts.tv_sec); 307 ino->atime_sec = tmp_le64; 308 ino->ctime_sec = tmp_le64; 309 ino->mtime_sec = tmp_le64; 310 tmp_le32 = cpu_to_le32(ts.tv_nsec); 311 ino->atime_nsec = tmp_le32; 312 ino->ctime_nsec = tmp_le32; 313 ino->mtime_nsec = tmp_le32; 314 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO); 315 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ); 316 317 /* Set compression enabled by default */ 318 ino->flags = cpu_to_le32(UBIFS_COMPR_FL); 319 320 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ, 321 main_first + DEFAULT_DATA_LEB, 0); 322 kfree(ino); 323 if (err) 324 return err; 325 326 dbg_gen("root inode created at LEB %d:0", 327 main_first + DEFAULT_DATA_LEB); 328 329 /* 330 * The first node in the log has to be the commit start node. This is 331 * always the case during normal file-system operation. Write a fake 332 * commit start node to the log. 333 */ 334 tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size); 335 cs = kzalloc(tmp, GFP_KERNEL); 336 if (!cs) 337 return -ENOMEM; 338 339 cs->ch.node_type = UBIFS_CS_NODE; 340 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0); 341 kfree(cs); 342 if (err) 343 return err; 344 345 ubifs_msg(c, "default file-system created"); 346 return 0; 347 } 348 349 /** 350 * validate_sb - validate superblock node. 351 * @c: UBIFS file-system description object 352 * @sup: superblock node 353 * 354 * This function validates superblock node @sup. Since most of data was read 355 * from the superblock and stored in @c, the function validates fields in @c 356 * instead. Returns zero in case of success and %-EINVAL in case of validation 357 * failure. 358 */ 359 static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup) 360 { 361 long long max_bytes; 362 int err = 1, min_leb_cnt; 363 364 if (!c->key_hash) { 365 err = 2; 366 goto failed; 367 } 368 369 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) { 370 err = 3; 371 goto failed; 372 } 373 374 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) { 375 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real", 376 le32_to_cpu(sup->min_io_size), c->min_io_size); 377 goto failed; 378 } 379 380 if (le32_to_cpu(sup->leb_size) != c->leb_size) { 381 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real", 382 le32_to_cpu(sup->leb_size), c->leb_size); 383 goto failed; 384 } 385 386 if (c->log_lebs < UBIFS_MIN_LOG_LEBS || 387 c->lpt_lebs < UBIFS_MIN_LPT_LEBS || 388 c->orph_lebs < UBIFS_MIN_ORPH_LEBS || 389 c->main_lebs < UBIFS_MIN_MAIN_LEBS) { 390 err = 4; 391 goto failed; 392 } 393 394 /* 395 * Calculate minimum allowed amount of main area LEBs. This is very 396 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we 397 * have just read from the superblock. 398 */ 399 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs; 400 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6; 401 402 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) { 403 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required", 404 c->leb_cnt, c->vi.size, min_leb_cnt); 405 goto failed; 406 } 407 408 if (c->max_leb_cnt < c->leb_cnt) { 409 ubifs_err(c, "max. LEB count %d less than LEB count %d", 410 c->max_leb_cnt, c->leb_cnt); 411 goto failed; 412 } 413 414 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) { 415 ubifs_err(c, "too few main LEBs count %d, must be at least %d", 416 c->main_lebs, UBIFS_MIN_MAIN_LEBS); 417 goto failed; 418 } 419 420 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS; 421 if (c->max_bud_bytes < max_bytes) { 422 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes", 423 c->max_bud_bytes, max_bytes); 424 goto failed; 425 } 426 427 max_bytes = (long long)c->leb_size * c->main_lebs; 428 if (c->max_bud_bytes > max_bytes) { 429 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area", 430 c->max_bud_bytes, max_bytes); 431 goto failed; 432 } 433 434 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 || 435 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) { 436 err = 9; 437 goto failed; 438 } 439 440 if (c->fanout < UBIFS_MIN_FANOUT || 441 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) { 442 err = 10; 443 goto failed; 444 } 445 446 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT && 447 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - 448 c->log_lebs - c->lpt_lebs - c->orph_lebs)) { 449 err = 11; 450 goto failed; 451 } 452 453 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs + 454 c->orph_lebs + c->main_lebs != c->leb_cnt) { 455 err = 12; 456 goto failed; 457 } 458 459 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) { 460 err = 13; 461 goto failed; 462 } 463 464 if (c->rp_size < 0 || max_bytes < c->rp_size) { 465 err = 14; 466 goto failed; 467 } 468 469 if (le32_to_cpu(sup->time_gran) > 1000000000 || 470 le32_to_cpu(sup->time_gran) < 1) { 471 err = 15; 472 goto failed; 473 } 474 475 if (!c->double_hash && c->fmt_version >= 5) { 476 err = 16; 477 goto failed; 478 } 479 480 if (c->encrypted && c->fmt_version < 5) { 481 err = 17; 482 goto failed; 483 } 484 485 return 0; 486 487 failed: 488 ubifs_err(c, "bad superblock, error %d", err); 489 ubifs_dump_node(c, sup); 490 return -EINVAL; 491 } 492 493 /** 494 * ubifs_read_sb_node - read superblock node. 495 * @c: UBIFS file-system description object 496 * 497 * This function returns a pointer to the superblock node or a negative error 498 * code. Note, the user of this function is responsible of kfree()'ing the 499 * returned superblock buffer. 500 */ 501 struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c) 502 { 503 struct ubifs_sb_node *sup; 504 int err; 505 506 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS); 507 if (!sup) 508 return ERR_PTR(-ENOMEM); 509 510 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ, 511 UBIFS_SB_LNUM, 0); 512 if (err) { 513 kfree(sup); 514 return ERR_PTR(err); 515 } 516 517 return sup; 518 } 519 520 /** 521 * ubifs_write_sb_node - write superblock node. 522 * @c: UBIFS file-system description object 523 * @sup: superblock node read with 'ubifs_read_sb_node()' 524 * 525 * This function returns %0 on success and a negative error code on failure. 526 */ 527 int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) 528 { 529 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); 530 531 ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1); 532 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len); 533 } 534 535 /** 536 * ubifs_read_superblock - read superblock. 537 * @c: UBIFS file-system description object 538 * 539 * This function finds, reads and checks the superblock. If an empty UBI volume 540 * is being mounted, this function creates default superblock. Returns zero in 541 * case of success, and a negative error code in case of failure. 542 */ 543 int ubifs_read_superblock(struct ubifs_info *c) 544 { 545 int err, sup_flags; 546 struct ubifs_sb_node *sup; 547 548 if (c->empty) { 549 err = create_default_filesystem(c); 550 if (err) 551 return err; 552 } 553 554 sup = ubifs_read_sb_node(c); 555 if (IS_ERR(sup)) 556 return PTR_ERR(sup); 557 558 c->fmt_version = le32_to_cpu(sup->fmt_version); 559 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); 560 561 /* 562 * The software supports all previous versions but not future versions, 563 * due to the unavailability of time-travelling equipment. 564 */ 565 if (c->fmt_version > UBIFS_FORMAT_VERSION) { 566 ubifs_assert(!c->ro_media || c->ro_mount); 567 if (!c->ro_mount || 568 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { 569 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d", 570 c->fmt_version, c->ro_compat_version, 571 UBIFS_FORMAT_VERSION, 572 UBIFS_RO_COMPAT_VERSION); 573 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { 574 ubifs_msg(c, "only R/O mounting is possible"); 575 err = -EROFS; 576 } else 577 err = -EINVAL; 578 goto out; 579 } 580 581 /* 582 * The FS is mounted R/O, and the media format is 583 * R/O-compatible with the UBIFS implementation, so we can 584 * mount. 585 */ 586 c->rw_incompat = 1; 587 } 588 589 if (c->fmt_version < 3) { 590 ubifs_err(c, "on-flash format version %d is not supported", 591 c->fmt_version); 592 err = -EINVAL; 593 goto out; 594 } 595 596 switch (sup->key_hash) { 597 case UBIFS_KEY_HASH_R5: 598 c->key_hash = key_r5_hash; 599 c->key_hash_type = UBIFS_KEY_HASH_R5; 600 break; 601 602 case UBIFS_KEY_HASH_TEST: 603 c->key_hash = key_test_hash; 604 c->key_hash_type = UBIFS_KEY_HASH_TEST; 605 break; 606 }; 607 608 c->key_fmt = sup->key_fmt; 609 610 switch (c->key_fmt) { 611 case UBIFS_SIMPLE_KEY_FMT: 612 c->key_len = UBIFS_SK_LEN; 613 break; 614 default: 615 ubifs_err(c, "unsupported key format"); 616 err = -EINVAL; 617 goto out; 618 } 619 620 c->leb_cnt = le32_to_cpu(sup->leb_cnt); 621 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); 622 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); 623 c->log_lebs = le32_to_cpu(sup->log_lebs); 624 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); 625 c->orph_lebs = le32_to_cpu(sup->orph_lebs); 626 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; 627 c->fanout = le32_to_cpu(sup->fanout); 628 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); 629 c->rp_size = le64_to_cpu(sup->rp_size); 630 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid)); 631 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid)); 632 sup_flags = le32_to_cpu(sup->flags); 633 if (!c->mount_opts.override_compr) 634 c->default_compr = le16_to_cpu(sup->default_compr); 635 636 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); 637 memcpy(&c->uuid, &sup->uuid, 16); 638 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); 639 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); 640 c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); 641 c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); 642 643 if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { 644 ubifs_err(c, "Unknown feature flags found: %#x", 645 sup_flags & ~UBIFS_FLG_MASK); 646 err = -EINVAL; 647 goto out; 648 } 649 650 #ifndef CONFIG_UBIFS_FS_ENCRYPTION 651 if (c->encrypted) { 652 ubifs_err(c, "file system contains encrypted files but UBIFS" 653 " was built without crypto support."); 654 err = -EINVAL; 655 goto out; 656 } 657 #endif 658 659 /* Automatically increase file system size to the maximum size */ 660 c->old_leb_cnt = c->leb_cnt; 661 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { 662 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); 663 if (c->ro_mount) 664 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs", 665 c->old_leb_cnt, c->leb_cnt); 666 else { 667 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs", 668 c->old_leb_cnt, c->leb_cnt); 669 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 670 err = ubifs_write_sb_node(c, sup); 671 if (err) 672 goto out; 673 c->old_leb_cnt = c->leb_cnt; 674 } 675 } 676 677 c->log_bytes = (long long)c->log_lebs * c->leb_size; 678 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; 679 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; 680 c->lpt_last = c->lpt_first + c->lpt_lebs - 1; 681 c->orph_first = c->lpt_last + 1; 682 c->orph_last = c->orph_first + c->orph_lebs - 1; 683 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; 684 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; 685 c->main_first = c->leb_cnt - c->main_lebs; 686 687 err = validate_sb(c, sup); 688 out: 689 kfree(sup); 690 return err; 691 } 692 693 /** 694 * fixup_leb - fixup/unmap an LEB containing free space. 695 * @c: UBIFS file-system description object 696 * @lnum: the LEB number to fix up 697 * @len: number of used bytes in LEB (starting at offset 0) 698 * 699 * This function reads the contents of the given LEB number @lnum, then fixes 700 * it up, so that empty min. I/O units in the end of LEB are actually erased on 701 * flash (rather than being just all-0xff real data). If the LEB is completely 702 * empty, it is simply unmapped. 703 */ 704 static int fixup_leb(struct ubifs_info *c, int lnum, int len) 705 { 706 int err; 707 708 ubifs_assert(len >= 0); 709 ubifs_assert(len % c->min_io_size == 0); 710 ubifs_assert(len < c->leb_size); 711 712 if (len == 0) { 713 dbg_mnt("unmap empty LEB %d", lnum); 714 return ubifs_leb_unmap(c, lnum); 715 } 716 717 dbg_mnt("fixup LEB %d, data len %d", lnum, len); 718 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1); 719 if (err) 720 return err; 721 722 return ubifs_leb_change(c, lnum, c->sbuf, len); 723 } 724 725 /** 726 * fixup_free_space - find & remap all LEBs containing free space. 727 * @c: UBIFS file-system description object 728 * 729 * This function walks through all LEBs in the filesystem and fiexes up those 730 * containing free/empty space. 731 */ 732 static int fixup_free_space(struct ubifs_info *c) 733 { 734 int lnum, err = 0; 735 struct ubifs_lprops *lprops; 736 737 ubifs_get_lprops(c); 738 739 /* Fixup LEBs in the master area */ 740 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) { 741 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz); 742 if (err) 743 goto out; 744 } 745 746 /* Unmap unused log LEBs */ 747 lnum = ubifs_next_log_lnum(c, c->lhead_lnum); 748 while (lnum != c->ltail_lnum) { 749 err = fixup_leb(c, lnum, 0); 750 if (err) 751 goto out; 752 lnum = ubifs_next_log_lnum(c, lnum); 753 } 754 755 /* 756 * Fixup the log head which contains the only a CS node at the 757 * beginning. 758 */ 759 err = fixup_leb(c, c->lhead_lnum, 760 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size)); 761 if (err) 762 goto out; 763 764 /* Fixup LEBs in the LPT area */ 765 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { 766 int free = c->ltab[lnum - c->lpt_first].free; 767 768 if (free > 0) { 769 err = fixup_leb(c, lnum, c->leb_size - free); 770 if (err) 771 goto out; 772 } 773 } 774 775 /* Unmap LEBs in the orphans area */ 776 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { 777 err = fixup_leb(c, lnum, 0); 778 if (err) 779 goto out; 780 } 781 782 /* Fixup LEBs in the main area */ 783 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { 784 lprops = ubifs_lpt_lookup(c, lnum); 785 if (IS_ERR(lprops)) { 786 err = PTR_ERR(lprops); 787 goto out; 788 } 789 790 if (lprops->free > 0) { 791 err = fixup_leb(c, lnum, c->leb_size - lprops->free); 792 if (err) 793 goto out; 794 } 795 } 796 797 out: 798 ubifs_release_lprops(c); 799 return err; 800 } 801 802 /** 803 * ubifs_fixup_free_space - find & fix all LEBs with free space. 804 * @c: UBIFS file-system description object 805 * 806 * This function fixes up LEBs containing free space on first mount, if the 807 * appropriate flag was set when the FS was created. Each LEB with one or more 808 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure 809 * the free space is actually erased. E.g., this is necessary for some NAND 810 * chips, since the free space may have been programmed like real "0xff" data 811 * (generating a non-0xff ECC), causing future writes to the not-really-erased 812 * NAND pages to behave badly. After the space is fixed up, the superblock flag 813 * is cleared, so that this is skipped for all future mounts. 814 */ 815 int ubifs_fixup_free_space(struct ubifs_info *c) 816 { 817 int err; 818 struct ubifs_sb_node *sup; 819 820 ubifs_assert(c->space_fixup); 821 ubifs_assert(!c->ro_mount); 822 823 ubifs_msg(c, "start fixing up free space"); 824 825 err = fixup_free_space(c); 826 if (err) 827 return err; 828 829 sup = ubifs_read_sb_node(c); 830 if (IS_ERR(sup)) 831 return PTR_ERR(sup); 832 833 /* Free-space fixup is no longer required */ 834 c->space_fixup = 0; 835 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); 836 837 err = ubifs_write_sb_node(c, sup); 838 kfree(sup); 839 if (err) 840 return err; 841 842 ubifs_msg(c, "free space fixup complete"); 843 return err; 844 } 845 846 int ubifs_enable_encryption(struct ubifs_info *c) 847 { 848 int err; 849 struct ubifs_sb_node *sup; 850 851 if (c->encrypted) 852 return 0; 853 854 if (c->ro_mount || c->ro_media) 855 return -EROFS; 856 857 if (c->fmt_version < 5) { 858 ubifs_err(c, "on-flash format version 5 is needed for encryption"); 859 return -EINVAL; 860 } 861 862 sup = ubifs_read_sb_node(c); 863 if (IS_ERR(sup)) 864 return PTR_ERR(sup); 865 866 sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION); 867 868 err = ubifs_write_sb_node(c, sup); 869 if (!err) 870 c->encrypted = 1; 871 kfree(sup); 872 873 return err; 874 } 875