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