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/random.h> 32#include <linux/math64.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 */ 73static 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; 166 167 sup->ch.node_type = UBIFS_SB_NODE; 168 sup->key_hash = UBIFS_KEY_HASH_R5; 169 sup->flags = cpu_to_le32(sup_flags); 170 sup->min_io_size = cpu_to_le32(c->min_io_size); 171 sup->leb_size = cpu_to_le32(c->leb_size); 172 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 173 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt); 174 sup->max_bud_bytes = cpu_to_le64(tmp64); 175 sup->log_lebs = cpu_to_le32(log_lebs); 176 sup->lpt_lebs = cpu_to_le32(lpt_lebs); 177 sup->orph_lebs = cpu_to_le32(orph_lebs); 178 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT); 179 sup->fanout = cpu_to_le32(DEFAULT_FANOUT); 180 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt); 181 sup->fmt_version = cpu_to_le32(UBIFS_FORMAT_VERSION); 182 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN); 183 if (c->mount_opts.override_compr) 184 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type); 185 else 186 sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO); 187 188 generate_random_uuid(sup->uuid); 189 190 main_bytes = (long long)main_lebs * c->leb_size; 191 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100); 192 if (tmp64 > DEFAULT_MAX_RP_SIZE) 193 tmp64 = DEFAULT_MAX_RP_SIZE; 194 sup->rp_size = cpu_to_le64(tmp64); 195 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION); 196 197 err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0); 198 kfree(sup); 199 if (err) 200 return err; 201 202 dbg_gen("default superblock created at LEB 0:0"); 203 204 /* Create default master node */ 205 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); 206 if (!mst) 207 return -ENOMEM; 208 209 mst->ch.node_type = UBIFS_MST_NODE; 210 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM); 211 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO); 212 mst->cmt_no = 0; 213 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); 214 mst->root_offs = 0; 215 tmp = ubifs_idx_node_sz(c, 1); 216 mst->root_len = cpu_to_le32(tmp); 217 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB); 218 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); 219 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size)); 220 mst->index_size = cpu_to_le64(ALIGN(tmp, 8)); 221 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum); 222 mst->lpt_offs = cpu_to_le32(c->lpt_offs); 223 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum); 224 mst->nhead_offs = cpu_to_le32(c->nhead_offs); 225 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum); 226 mst->ltab_offs = cpu_to_le32(c->ltab_offs); 227 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum); 228 mst->lsave_offs = cpu_to_le32(c->lsave_offs); 229 mst->lscan_lnum = cpu_to_le32(main_first); 230 mst->empty_lebs = cpu_to_le32(main_lebs - 2); 231 mst->idx_lebs = cpu_to_le32(1); 232 mst->leb_cnt = cpu_to_le32(c->leb_cnt); 233 234 /* Calculate lprops statistics */ 235 tmp64 = main_bytes; 236 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); 237 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); 238 mst->total_free = cpu_to_le64(tmp64); 239 240 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); 241 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) - 242 UBIFS_INO_NODE_SZ; 243 tmp64 += ino_waste; 244 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8); 245 mst->total_dirty = cpu_to_le64(tmp64); 246 247 /* The indexing LEB does not contribute to dark space */ 248 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm); 249 mst->total_dark = cpu_to_le64(tmp64); 250 251 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); 252 253 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0); 254 if (err) { 255 kfree(mst); 256 return err; 257 } 258 err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 259 0); 260 kfree(mst); 261 if (err) 262 return err; 263 264 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM); 265 266 /* Create the root indexing node */ 267 tmp = ubifs_idx_node_sz(c, 1); 268 idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL); 269 if (!idx) 270 return -ENOMEM; 271 272 c->key_fmt = UBIFS_SIMPLE_KEY_FMT; 273 c->key_hash = key_r5_hash; 274 275 idx->ch.node_type = UBIFS_IDX_NODE; 276 idx->child_cnt = cpu_to_le16(1); 277 ino_key_init(c, &key, UBIFS_ROOT_INO); 278 br = ubifs_idx_branch(c, idx, 0); 279 key_write_idx(c, &key, &br->key); 280 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB); 281 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ); 282 err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0); 283 kfree(idx); 284 if (err) 285 return err; 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 tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); 292 ino = kzalloc(tmp, GFP_KERNEL); 293 if (!ino) 294 return -ENOMEM; 295 296 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO); 297 ino->ch.node_type = UBIFS_INO_NODE; 298 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); 299 ino->nlink = cpu_to_le32(2); 300 tmp_le64 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec); 301 ino->atime_sec = tmp_le64; 302 ino->ctime_sec = tmp_le64; 303 ino->mtime_sec = tmp_le64; 304 ino->atime_nsec = 0; 305 ino->ctime_nsec = 0; 306 ino->mtime_nsec = 0; 307 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO); 308 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ); 309 310 /* Set compression enabled by default */ 311 ino->flags = cpu_to_le32(UBIFS_COMPR_FL); 312 313 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ, 314 main_first + DEFAULT_DATA_LEB, 0); 315 kfree(ino); 316 if (err) 317 return err; 318 319 dbg_gen("root inode created at LEB %d:0", 320 main_first + DEFAULT_DATA_LEB); 321 322 /* 323 * The first node in the log has to be the commit start node. This is 324 * always the case during normal file-system operation. Write a fake 325 * commit start node to the log. 326 */ 327 tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size); 328 cs = kzalloc(tmp, GFP_KERNEL); 329 if (!cs) 330 return -ENOMEM; 331 332 cs->ch.node_type = UBIFS_CS_NODE; 333 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0); 334 kfree(cs); 335 if (err) 336 return err; 337 338 ubifs_msg(c, "default file-system created"); 339 return 0; 340} 341 342/** 343 * validate_sb - validate superblock node. 344 * @c: UBIFS file-system description object 345 * @sup: superblock node 346 * 347 * This function validates superblock node @sup. Since most of data was read 348 * from the superblock and stored in @c, the function validates fields in @c 349 * instead. Returns zero in case of success and %-EINVAL in case of validation 350 * failure. 351 */ 352static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup) 353{ 354 long long max_bytes; 355 int err = 1, min_leb_cnt; 356 357 if (!c->key_hash) { 358 err = 2; 359 goto failed; 360 } 361 362 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) { 363 err = 3; 364 goto failed; 365 } 366 367 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) { 368 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real", 369 le32_to_cpu(sup->min_io_size), c->min_io_size); 370 goto failed; 371 } 372 373 if (le32_to_cpu(sup->leb_size) != c->leb_size) { 374 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real", 375 le32_to_cpu(sup->leb_size), c->leb_size); 376 goto failed; 377 } 378 379 if (c->log_lebs < UBIFS_MIN_LOG_LEBS || 380 c->lpt_lebs < UBIFS_MIN_LPT_LEBS || 381 c->orph_lebs < UBIFS_MIN_ORPH_LEBS || 382 c->main_lebs < UBIFS_MIN_MAIN_LEBS) { 383 err = 4; 384 goto failed; 385 } 386 387 /* 388 * Calculate minimum allowed amount of main area LEBs. This is very 389 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we 390 * have just read from the superblock. 391 */ 392 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs; 393 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6; 394 395 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) { 396 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required", 397 c->leb_cnt, c->vi.size, min_leb_cnt); 398 goto failed; 399 } 400 401 if (c->max_leb_cnt < c->leb_cnt) { 402 ubifs_err(c, "max. LEB count %d less than LEB count %d", 403 c->max_leb_cnt, c->leb_cnt); 404 goto failed; 405 } 406 407 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) { 408 ubifs_err(c, "too few main LEBs count %d, must be at least %d", 409 c->main_lebs, UBIFS_MIN_MAIN_LEBS); 410 goto failed; 411 } 412 413 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS; 414 if (c->max_bud_bytes < max_bytes) { 415 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes", 416 c->max_bud_bytes, max_bytes); 417 goto failed; 418 } 419 420 max_bytes = (long long)c->leb_size * c->main_lebs; 421 if (c->max_bud_bytes > max_bytes) { 422 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area", 423 c->max_bud_bytes, max_bytes); 424 goto failed; 425 } 426 427 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 || 428 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) { 429 err = 9; 430 goto failed; 431 } 432 433 if (c->fanout < UBIFS_MIN_FANOUT || 434 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) { 435 err = 10; 436 goto failed; 437 } 438 439 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT && 440 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - 441 c->log_lebs - c->lpt_lebs - c->orph_lebs)) { 442 err = 11; 443 goto failed; 444 } 445 446 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs + 447 c->orph_lebs + c->main_lebs != c->leb_cnt) { 448 err = 12; 449 goto failed; 450 } 451 452 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) { 453 err = 13; 454 goto failed; 455 } 456 457 if (c->rp_size < 0 || max_bytes < c->rp_size) { 458 err = 14; 459 goto failed; 460 } 461 462 if (le32_to_cpu(sup->time_gran) > 1000000000 || 463 le32_to_cpu(sup->time_gran) < 1) { 464 err = 15; 465 goto failed; 466 } 467 468 return 0; 469 470failed: 471 ubifs_err(c, "bad superblock, error %d", err); 472 ubifs_dump_node(c, sup); 473 return -EINVAL; 474} 475 476/** 477 * ubifs_read_sb_node - read superblock node. 478 * @c: UBIFS file-system description object 479 * 480 * This function returns a pointer to the superblock node or a negative error 481 * code. Note, the user of this function is responsible of kfree()'ing the 482 * returned superblock buffer. 483 */ 484struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c) 485{ 486 struct ubifs_sb_node *sup; 487 int err; 488 489 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS); 490 if (!sup) 491 return ERR_PTR(-ENOMEM); 492 493 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ, 494 UBIFS_SB_LNUM, 0); 495 if (err) { 496 kfree(sup); 497 return ERR_PTR(err); 498 } 499 500 return sup; 501} 502 503/** 504 * ubifs_write_sb_node - write superblock node. 505 * @c: UBIFS file-system description object 506 * @sup: superblock node read with 'ubifs_read_sb_node()' 507 * 508 * This function returns %0 on success and a negative error code on failure. 509 */ 510int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) 511{ 512 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); 513 514 ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1); 515 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len); 516} 517 518/** 519 * ubifs_read_superblock - read superblock. 520 * @c: UBIFS file-system description object 521 * 522 * This function finds, reads and checks the superblock. If an empty UBI volume 523 * is being mounted, this function creates default superblock. Returns zero in 524 * case of success, and a negative error code in case of failure. 525 */ 526int ubifs_read_superblock(struct ubifs_info *c) 527{ 528 int err, sup_flags; 529 struct ubifs_sb_node *sup; 530 531 if (c->empty) { 532 err = create_default_filesystem(c); 533 if (err) 534 return err; 535 } 536 537 sup = ubifs_read_sb_node(c); 538 if (IS_ERR(sup)) 539 return PTR_ERR(sup); 540 541 c->fmt_version = le32_to_cpu(sup->fmt_version); 542 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); 543 544 /* 545 * The software supports all previous versions but not future versions, 546 * due to the unavailability of time-travelling equipment. 547 */ 548 if (c->fmt_version > UBIFS_FORMAT_VERSION) { 549 ubifs_assert(!c->ro_media || c->ro_mount); 550 if (!c->ro_mount || 551 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { 552 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d", 553 c->fmt_version, c->ro_compat_version, 554 UBIFS_FORMAT_VERSION, 555 UBIFS_RO_COMPAT_VERSION); 556 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { 557 ubifs_msg(c, "only R/O mounting is possible"); 558 err = -EROFS; 559 } else 560 err = -EINVAL; 561 goto out; 562 } 563 564 /* 565 * The FS is mounted R/O, and the media format is 566 * R/O-compatible with the UBIFS implementation, so we can 567 * mount. 568 */ 569 c->rw_incompat = 1; 570 } 571 572 if (c->fmt_version < 3) { 573 ubifs_err(c, "on-flash format version %d is not supported", 574 c->fmt_version); 575 err = -EINVAL; 576 goto out; 577 } 578 579 switch (sup->key_hash) { 580 case UBIFS_KEY_HASH_R5: 581 c->key_hash = key_r5_hash; 582 c->key_hash_type = UBIFS_KEY_HASH_R5; 583 break; 584 585 case UBIFS_KEY_HASH_TEST: 586 c->key_hash = key_test_hash; 587 c->key_hash_type = UBIFS_KEY_HASH_TEST; 588 break; 589 }; 590 591 c->key_fmt = sup->key_fmt; 592 593 switch (c->key_fmt) { 594 case UBIFS_SIMPLE_KEY_FMT: 595 c->key_len = UBIFS_SK_LEN; 596 break; 597 default: 598 ubifs_err(c, "unsupported key format"); 599 err = -EINVAL; 600 goto out; 601 } 602 603 c->leb_cnt = le32_to_cpu(sup->leb_cnt); 604 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); 605 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); 606 c->log_lebs = le32_to_cpu(sup->log_lebs); 607 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); 608 c->orph_lebs = le32_to_cpu(sup->orph_lebs); 609 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; 610 c->fanout = le32_to_cpu(sup->fanout); 611 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); 612 c->rp_size = le64_to_cpu(sup->rp_size); 613 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid)); 614 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid)); 615 sup_flags = le32_to_cpu(sup->flags); 616 if (!c->mount_opts.override_compr) 617 c->default_compr = le16_to_cpu(sup->default_compr); 618 619 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); 620 memcpy(&c->uuid, &sup->uuid, 16); 621 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); 622 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); 623 624 /* Automatically increase file system size to the maximum size */ 625 c->old_leb_cnt = c->leb_cnt; 626 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { 627 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); 628 if (c->ro_mount) 629 dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs", 630 c->old_leb_cnt, c->leb_cnt); 631 else { 632 dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs", 633 c->old_leb_cnt, c->leb_cnt); 634 sup->leb_cnt = cpu_to_le32(c->leb_cnt); 635 err = ubifs_write_sb_node(c, sup); 636 if (err) 637 goto out; 638 c->old_leb_cnt = c->leb_cnt; 639 } 640 } 641 642 c->log_bytes = (long long)c->log_lebs * c->leb_size; 643 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; 644 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; 645 c->lpt_last = c->lpt_first + c->lpt_lebs - 1; 646 c->orph_first = c->lpt_last + 1; 647 c->orph_last = c->orph_first + c->orph_lebs - 1; 648 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; 649 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; 650 c->main_first = c->leb_cnt - c->main_lebs; 651 652 err = validate_sb(c, sup); 653out: 654 kfree(sup); 655 return err; 656} 657 658/** 659 * fixup_leb - fixup/unmap an LEB containing free space. 660 * @c: UBIFS file-system description object 661 * @lnum: the LEB number to fix up 662 * @len: number of used bytes in LEB (starting at offset 0) 663 * 664 * This function reads the contents of the given LEB number @lnum, then fixes 665 * it up, so that empty min. I/O units in the end of LEB are actually erased on 666 * flash (rather than being just all-0xff real data). If the LEB is completely 667 * empty, it is simply unmapped. 668 */ 669static int fixup_leb(struct ubifs_info *c, int lnum, int len) 670{ 671 int err; 672 673 ubifs_assert(len >= 0); 674 ubifs_assert(len % c->min_io_size == 0); 675 ubifs_assert(len < c->leb_size); 676 677 if (len == 0) { 678 dbg_mnt("unmap empty LEB %d", lnum); 679 return ubifs_leb_unmap(c, lnum); 680 } 681 682 dbg_mnt("fixup LEB %d, data len %d", lnum, len); 683 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1); 684 if (err) 685 return err; 686 687 return ubifs_leb_change(c, lnum, c->sbuf, len); 688} 689 690/** 691 * fixup_free_space - find & remap all LEBs containing free space. 692 * @c: UBIFS file-system description object 693 * 694 * This function walks through all LEBs in the filesystem and fiexes up those 695 * containing free/empty space. 696 */ 697static int fixup_free_space(struct ubifs_info *c) 698{ 699 int lnum, err = 0; 700 struct ubifs_lprops *lprops; 701 702 ubifs_get_lprops(c); 703 704 /* Fixup LEBs in the master area */ 705 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) { 706 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz); 707 if (err) 708 goto out; 709 } 710 711 /* Unmap unused log LEBs */ 712 lnum = ubifs_next_log_lnum(c, c->lhead_lnum); 713 while (lnum != c->ltail_lnum) { 714 err = fixup_leb(c, lnum, 0); 715 if (err) 716 goto out; 717 lnum = ubifs_next_log_lnum(c, lnum); 718 } 719 720 /* 721 * Fixup the log head which contains the only a CS node at the 722 * beginning. 723 */ 724 err = fixup_leb(c, c->lhead_lnum, 725 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size)); 726 if (err) 727 goto out; 728 729 /* Fixup LEBs in the LPT area */ 730 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { 731 int free = c->ltab[lnum - c->lpt_first].free; 732 733 if (free > 0) { 734 err = fixup_leb(c, lnum, c->leb_size - free); 735 if (err) 736 goto out; 737 } 738 } 739 740 /* Unmap LEBs in the orphans area */ 741 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { 742 err = fixup_leb(c, lnum, 0); 743 if (err) 744 goto out; 745 } 746 747 /* Fixup LEBs in the main area */ 748 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { 749 lprops = ubifs_lpt_lookup(c, lnum); 750 if (IS_ERR(lprops)) { 751 err = PTR_ERR(lprops); 752 goto out; 753 } 754 755 if (lprops->free > 0) { 756 err = fixup_leb(c, lnum, c->leb_size - lprops->free); 757 if (err) 758 goto out; 759 } 760 } 761 762out: 763 ubifs_release_lprops(c); 764 return err; 765} 766 767/** 768 * ubifs_fixup_free_space - find & fix all LEBs with free space. 769 * @c: UBIFS file-system description object 770 * 771 * This function fixes up LEBs containing free space on first mount, if the 772 * appropriate flag was set when the FS was created. Each LEB with one or more 773 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure 774 * the free space is actually erased. E.g., this is necessary for some NAND 775 * chips, since the free space may have been programmed like real "0xff" data 776 * (generating a non-0xff ECC), causing future writes to the not-really-erased 777 * NAND pages to behave badly. After the space is fixed up, the superblock flag 778 * is cleared, so that this is skipped for all future mounts. 779 */ 780int ubifs_fixup_free_space(struct ubifs_info *c) 781{ 782 int err; 783 struct ubifs_sb_node *sup; 784 785 ubifs_assert(c->space_fixup); 786 ubifs_assert(!c->ro_mount); 787 788 ubifs_msg(c, "start fixing up free space"); 789 790 err = fixup_free_space(c); 791 if (err) 792 return err; 793 794 sup = ubifs_read_sb_node(c); 795 if (IS_ERR(sup)) 796 return PTR_ERR(sup); 797 798 /* Free-space fixup is no longer required */ 799 c->space_fixup = 0; 800 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); 801 802 err = ubifs_write_sb_node(c, sup); 803 kfree(sup); 804 if (err) 805 return err; 806 807 ubifs_msg(c, "free space fixup complete"); 808 return err; 809} 810