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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * This file is part of UBIFS.4 *5 * Copyright (C) 2006-2008 Nokia Corporation.6 *7 * Authors: Artem Bityutskiy (Битюцкий Артём)8 * Adrian Hunter9 */10 11/*12 * This file implements UBIFS superblock. The superblock is stored at the first13 * LEB of the volume and is never changed by UBIFS. Only user-space tools may14 * change it. The superblock node mostly contains geometry information.15 */16 17#include "ubifs.h"18#include <linux/slab.h>19#include <linux/math64.h>20#include <linux/uuid.h>21 22/*23 * Default journal size in logical eraseblocks as a percent of total24 * flash size.25 */26#define DEFAULT_JNL_PERCENT 527 28/* Default maximum journal size in bytes */29#define DEFAULT_MAX_JNL (32*1024*1024)30 31/* Default indexing tree fanout */32#define DEFAULT_FANOUT 833 34/* Default number of data journal heads */35#define DEFAULT_JHEADS_CNT 136 37/* Default positions of different LEBs in the main area */38#define DEFAULT_IDX_LEB 039#define DEFAULT_DATA_LEB 140#define DEFAULT_GC_LEB 241 42/* Default number of LEB numbers in LPT's save table */43#define DEFAULT_LSAVE_CNT 25644 45/* Default reserved pool size as a percent of maximum free space */46#define DEFAULT_RP_PERCENT 547 48/* The default maximum size of reserved pool in bytes */49#define DEFAULT_MAX_RP_SIZE (5*1024*1024)50 51/* Default time granularity in nanoseconds */52#define DEFAULT_TIME_GRAN 100000000053 54static int get_default_compressor(struct ubifs_info *c)55{56 if (ubifs_compr_present(c, UBIFS_COMPR_ZSTD))57 return UBIFS_COMPR_ZSTD;58 59 if (ubifs_compr_present(c, UBIFS_COMPR_LZO))60 return UBIFS_COMPR_LZO;61 62 if (ubifs_compr_present(c, UBIFS_COMPR_ZLIB))63 return UBIFS_COMPR_ZLIB;64 65 return UBIFS_COMPR_NONE;66}67 68/**69 * create_default_filesystem - format empty UBI volume.70 * @c: UBIFS file-system description object71 *72 * This function creates default empty file-system. Returns zero in case of73 * success and a negative error code in case of failure.74 */75static int create_default_filesystem(struct ubifs_info *c)76{77 struct ubifs_sb_node *sup;78 struct ubifs_mst_node *mst;79 struct ubifs_idx_node *idx;80 struct ubifs_branch *br;81 struct ubifs_ino_node *ino;82 struct ubifs_cs_node *cs;83 union ubifs_key key;84 int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first;85 int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0;86 int min_leb_cnt = UBIFS_MIN_LEB_CNT;87 int idx_node_size;88 long long tmp64, main_bytes;89 __le64 tmp_le64;90 struct timespec64 ts;91 u8 hash[UBIFS_HASH_ARR_SZ];92 u8 hash_lpt[UBIFS_HASH_ARR_SZ];93 94 /* Some functions called from here depend on the @c->key_len filed */95 c->key_len = UBIFS_SK_LEN;96 97 /*98 * First of all, we have to calculate default file-system geometry -99 * log size, journal size, etc.100 */101 if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)102 /* We can first multiply then divide and have no overflow */103 jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;104 else105 jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;106 107 if (jnl_lebs < UBIFS_MIN_JNL_LEBS)108 jnl_lebs = UBIFS_MIN_JNL_LEBS;109 if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)110 jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;111 112 /*113 * The log should be large enough to fit reference nodes for all bud114 * LEBs. Because buds do not have to start from the beginning of LEBs115 * (half of the LEB may contain committed data), the log should116 * generally be larger, make it twice as large.117 */118 tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;119 log_lebs = tmp / c->leb_size;120 /* Plus one LEB reserved for commit */121 log_lebs += 1;122 if (c->leb_cnt - min_leb_cnt > 8) {123 /* And some extra space to allow writes while committing */124 log_lebs += 1;125 min_leb_cnt += 1;126 }127 128 max_buds = jnl_lebs - log_lebs;129 if (max_buds < UBIFS_MIN_BUD_LEBS)130 max_buds = UBIFS_MIN_BUD_LEBS;131 132 /*133 * Orphan nodes are stored in a separate area. One node can store a lot134 * of orphan inode numbers, but when new orphan comes we just add a new135 * orphan node. At some point the nodes are consolidated into one136 * orphan node.137 */138 orph_lebs = UBIFS_MIN_ORPH_LEBS;139 if (c->leb_cnt - min_leb_cnt > 1)140 /*141 * For debugging purposes it is better to have at least 2142 * orphan LEBs, because the orphan subsystem would need to do143 * consolidations and would be stressed more.144 */145 orph_lebs += 1;146 147 main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;148 main_lebs -= orph_lebs;149 150 lpt_first = UBIFS_LOG_LNUM + log_lebs;151 c->lsave_cnt = DEFAULT_LSAVE_CNT;152 c->max_leb_cnt = c->leb_cnt;153 err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,154 &big_lpt, hash_lpt);155 if (err)156 return err;157 158 dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,159 lpt_first + lpt_lebs - 1);160 161 main_first = c->leb_cnt - main_lebs;162 163 sup = kzalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_KERNEL);164 mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);165 idx_node_size = ubifs_idx_node_sz(c, 1);166 idx = kzalloc(ALIGN(idx_node_size, c->min_io_size), GFP_KERNEL);167 ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL);168 cs = kzalloc(ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size), GFP_KERNEL);169 170 if (!sup || !mst || !idx || !ino || !cs) {171 err = -ENOMEM;172 goto out;173 }174 175 /* Create default superblock */176 177 tmp64 = (long long)max_buds * c->leb_size;178 if (big_lpt)179 sup_flags |= UBIFS_FLG_BIGLPT;180 if (ubifs_default_version > 4)181 sup_flags |= UBIFS_FLG_DOUBLE_HASH;182 183 if (ubifs_authenticated(c)) {184 sup_flags |= UBIFS_FLG_AUTHENTICATION;185 sup->hash_algo = cpu_to_le16(c->auth_hash_algo);186 err = ubifs_hmac_wkm(c, sup->hmac_wkm);187 if (err)188 goto out;189 } else {190 sup->hash_algo = cpu_to_le16(0xffff);191 }192 193 sup->ch.node_type = UBIFS_SB_NODE;194 sup->key_hash = UBIFS_KEY_HASH_R5;195 sup->flags = cpu_to_le32(sup_flags);196 sup->min_io_size = cpu_to_le32(c->min_io_size);197 sup->leb_size = cpu_to_le32(c->leb_size);198 sup->leb_cnt = cpu_to_le32(c->leb_cnt);199 sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);200 sup->max_bud_bytes = cpu_to_le64(tmp64);201 sup->log_lebs = cpu_to_le32(log_lebs);202 sup->lpt_lebs = cpu_to_le32(lpt_lebs);203 sup->orph_lebs = cpu_to_le32(orph_lebs);204 sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);205 sup->fanout = cpu_to_le32(DEFAULT_FANOUT);206 sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);207 sup->fmt_version = cpu_to_le32(ubifs_default_version);208 sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);209 if (c->mount_opts.override_compr)210 sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);211 else212 sup->default_compr = cpu_to_le16(get_default_compressor(c));213 214 generate_random_uuid(sup->uuid);215 216 main_bytes = (long long)main_lebs * c->leb_size;217 tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);218 if (tmp64 > DEFAULT_MAX_RP_SIZE)219 tmp64 = DEFAULT_MAX_RP_SIZE;220 sup->rp_size = cpu_to_le64(tmp64);221 sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION);222 223 dbg_gen("default superblock created at LEB 0:0");224 225 /* Create default master node */226 227 mst->ch.node_type = UBIFS_MST_NODE;228 mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);229 mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);230 mst->cmt_no = 0;231 mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);232 mst->root_offs = 0;233 tmp = ubifs_idx_node_sz(c, 1);234 mst->root_len = cpu_to_le32(tmp);235 mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);236 mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);237 mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));238 mst->index_size = cpu_to_le64(ALIGN(tmp, 8));239 mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);240 mst->lpt_offs = cpu_to_le32(c->lpt_offs);241 mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);242 mst->nhead_offs = cpu_to_le32(c->nhead_offs);243 mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);244 mst->ltab_offs = cpu_to_le32(c->ltab_offs);245 mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);246 mst->lsave_offs = cpu_to_le32(c->lsave_offs);247 mst->lscan_lnum = cpu_to_le32(main_first);248 mst->empty_lebs = cpu_to_le32(main_lebs - 2);249 mst->idx_lebs = cpu_to_le32(1);250 mst->leb_cnt = cpu_to_le32(c->leb_cnt);251 ubifs_copy_hash(c, hash_lpt, mst->hash_lpt);252 253 /* Calculate lprops statistics */254 tmp64 = main_bytes;255 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);256 tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);257 mst->total_free = cpu_to_le64(tmp64);258 259 tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);260 ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -261 UBIFS_INO_NODE_SZ;262 tmp64 += ino_waste;263 tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);264 mst->total_dirty = cpu_to_le64(tmp64);265 266 /* The indexing LEB does not contribute to dark space */267 tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm);268 mst->total_dark = cpu_to_le64(tmp64);269 270 mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);271 272 dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);273 274 /* Create the root indexing node */275 276 c->key_fmt = UBIFS_SIMPLE_KEY_FMT;277 c->key_hash = key_r5_hash;278 279 idx->ch.node_type = UBIFS_IDX_NODE;280 idx->child_cnt = cpu_to_le16(1);281 ino_key_init(c, &key, UBIFS_ROOT_INO);282 br = ubifs_idx_branch(c, idx, 0);283 key_write_idx(c, &key, &br->key);284 br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);285 br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);286 287 dbg_gen("default root indexing node created LEB %d:0",288 main_first + DEFAULT_IDX_LEB);289 290 /* Create default root inode */291 292 ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);293 ino->ch.node_type = UBIFS_INO_NODE;294 ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);295 ino->nlink = cpu_to_le32(2);296 297 ktime_get_coarse_real_ts64(&ts);298 tmp_le64 = cpu_to_le64(ts.tv_sec);299 ino->atime_sec = tmp_le64;300 ino->ctime_sec = tmp_le64;301 ino->mtime_sec = tmp_le64;302 ino->atime_nsec = 0;303 ino->ctime_nsec = 0;304 ino->mtime_nsec = 0;305 ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);306 ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);307 308 /* Set compression enabled by default */309 ino->flags = cpu_to_le32(UBIFS_COMPR_FL);310 311 dbg_gen("root inode created at LEB %d:0",312 main_first + DEFAULT_DATA_LEB);313 314 /*315 * The first node in the log has to be the commit start node. This is316 * always the case during normal file-system operation. Write a fake317 * commit start node to the log.318 */319 320 cs->ch.node_type = UBIFS_CS_NODE;321 322 err = ubifs_write_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 0, 0,323 offsetof(struct ubifs_sb_node, hmac));324 if (err)325 goto out;326 327 err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,328 main_first + DEFAULT_DATA_LEB, 0);329 if (err)330 goto out;331 332 ubifs_node_calc_hash(c, ino, hash);333 ubifs_copy_hash(c, hash, ubifs_branch_hash(c, br));334 335 err = ubifs_write_node(c, idx, idx_node_size, main_first + DEFAULT_IDX_LEB, 0);336 if (err)337 goto out;338 339 ubifs_node_calc_hash(c, idx, hash);340 ubifs_copy_hash(c, hash, mst->hash_root_idx);341 342 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0,343 offsetof(struct ubifs_mst_node, hmac));344 if (err)345 goto out;346 347 err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1,348 0, offsetof(struct ubifs_mst_node, hmac));349 if (err)350 goto out;351 352 err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0);353 if (err)354 goto out;355 356 ubifs_msg(c, "default file-system created");357 358 err = 0;359out:360 kfree(sup);361 kfree(mst);362 kfree(idx);363 kfree(ino);364 kfree(cs);365 366 return err;367}368 369/**370 * validate_sb - validate superblock node.371 * @c: UBIFS file-system description object372 * @sup: superblock node373 *374 * This function validates superblock node @sup. Since most of data was read375 * from the superblock and stored in @c, the function validates fields in @c376 * instead. Returns zero in case of success and %-EINVAL in case of validation377 * failure.378 */379static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)380{381 long long max_bytes;382 int err = 1, min_leb_cnt;383 384 if (!c->key_hash) {385 err = 2;386 goto failed;387 }388 389 if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {390 err = 3;391 goto failed;392 }393 394 if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {395 ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real",396 le32_to_cpu(sup->min_io_size), c->min_io_size);397 goto failed;398 }399 400 if (le32_to_cpu(sup->leb_size) != c->leb_size) {401 ubifs_err(c, "LEB size mismatch: %d in superblock, %d real",402 le32_to_cpu(sup->leb_size), c->leb_size);403 goto failed;404 }405 406 if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||407 c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||408 c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||409 c->main_lebs < UBIFS_MIN_MAIN_LEBS) {410 err = 4;411 goto failed;412 }413 414 /*415 * Calculate minimum allowed amount of main area LEBs. This is very416 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we417 * have just read from the superblock.418 */419 min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs;420 min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6;421 422 if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) {423 ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required",424 c->leb_cnt, c->vi.size, min_leb_cnt);425 goto failed;426 }427 428 if (c->max_leb_cnt < c->leb_cnt) {429 ubifs_err(c, "max. LEB count %d less than LEB count %d",430 c->max_leb_cnt, c->leb_cnt);431 goto failed;432 }433 434 if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {435 ubifs_err(c, "too few main LEBs count %d, must be at least %d",436 c->main_lebs, UBIFS_MIN_MAIN_LEBS);437 goto failed;438 }439 440 max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS;441 if (c->max_bud_bytes < max_bytes) {442 ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes",443 c->max_bud_bytes, max_bytes);444 goto failed;445 }446 447 max_bytes = (long long)c->leb_size * c->main_lebs;448 if (c->max_bud_bytes > max_bytes) {449 ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area",450 c->max_bud_bytes, max_bytes);451 goto failed;452 }453 454 if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||455 c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {456 err = 9;457 goto failed;458 }459 460 if (c->fanout < UBIFS_MIN_FANOUT ||461 ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {462 err = 10;463 goto failed;464 }465 466 if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&467 c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -468 c->log_lebs - c->lpt_lebs - c->orph_lebs)) {469 err = 11;470 goto failed;471 }472 473 if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +474 c->orph_lebs + c->main_lebs != c->leb_cnt) {475 err = 12;476 goto failed;477 }478 479 if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) {480 err = 13;481 goto failed;482 }483 484 if (c->rp_size < 0 || max_bytes < c->rp_size) {485 err = 14;486 goto failed;487 }488 489 if (le32_to_cpu(sup->time_gran) > 1000000000 ||490 le32_to_cpu(sup->time_gran) < 1) {491 err = 15;492 goto failed;493 }494 495 if (!c->double_hash && c->fmt_version >= 5) {496 err = 16;497 goto failed;498 }499 500 if (c->encrypted && c->fmt_version < 5) {501 err = 17;502 goto failed;503 }504 505 return 0;506 507failed:508 ubifs_err(c, "bad superblock, error %d", err);509 ubifs_dump_node(c, sup, ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size));510 return -EINVAL;511}512 513/**514 * ubifs_read_sb_node - read superblock node.515 * @c: UBIFS file-system description object516 *517 * This function returns a pointer to the superblock node or a negative error518 * code. Note, the user of this function is responsible of kfree()'ing the519 * returned superblock buffer.520 */521static struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)522{523 struct ubifs_sb_node *sup;524 int err;525 526 sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);527 if (!sup)528 return ERR_PTR(-ENOMEM);529 530 err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,531 UBIFS_SB_LNUM, 0);532 if (err) {533 kfree(sup);534 return ERR_PTR(err);535 }536 537 return sup;538}539 540static int authenticate_sb_node(struct ubifs_info *c,541 const struct ubifs_sb_node *sup)542{543 unsigned int sup_flags = le32_to_cpu(sup->flags);544 u8 hmac_wkm[UBIFS_HMAC_ARR_SZ];545 int authenticated = !!(sup_flags & UBIFS_FLG_AUTHENTICATION);546 int hash_algo;547 int err;548 549 if (c->authenticated && !authenticated) {550 ubifs_err(c, "authenticated FS forced, but found FS without authentication");551 return -EINVAL;552 }553 554 if (!c->authenticated && authenticated) {555 ubifs_err(c, "authenticated FS found, but no key given");556 return -EINVAL;557 }558 559 ubifs_msg(c, "Mounting in %sauthenticated mode",560 c->authenticated ? "" : "un");561 562 if (!c->authenticated)563 return 0;564 565 if (!IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION))566 return -EOPNOTSUPP;567 568 hash_algo = le16_to_cpu(sup->hash_algo);569 if (hash_algo >= HASH_ALGO__LAST) {570 ubifs_err(c, "superblock uses unknown hash algo %d",571 hash_algo);572 return -EINVAL;573 }574 575 if (strcmp(hash_algo_name[hash_algo], c->auth_hash_name)) {576 ubifs_err(c, "This filesystem uses %s for hashing,"577 " but %s is specified", hash_algo_name[hash_algo],578 c->auth_hash_name);579 return -EINVAL;580 }581 582 /*583 * The super block node can either be authenticated by a HMAC or584 * by a signature in a ubifs_sig_node directly following the585 * super block node to support offline image creation.586 */587 if (ubifs_hmac_zero(c, sup->hmac)) {588 err = ubifs_sb_verify_signature(c, sup);589 } else {590 err = ubifs_hmac_wkm(c, hmac_wkm);591 if (err)592 return err;593 if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) {594 ubifs_err(c, "provided key does not fit");595 return -ENOKEY;596 }597 err = ubifs_node_verify_hmac(c, sup, sizeof(*sup),598 offsetof(struct ubifs_sb_node,599 hmac));600 }601 602 if (err)603 ubifs_err(c, "Failed to authenticate superblock: %d", err);604 605 return err;606}607 608/**609 * ubifs_write_sb_node - write superblock node.610 * @c: UBIFS file-system description object611 * @sup: superblock node read with 'ubifs_read_sb_node()'612 *613 * This function returns %0 on success and a negative error code on failure.614 */615int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)616{617 int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);618 int err;619 620 err = ubifs_prepare_node_hmac(c, sup, UBIFS_SB_NODE_SZ,621 offsetof(struct ubifs_sb_node, hmac), 1);622 if (err)623 return err;624 625 return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len);626}627 628/**629 * ubifs_read_superblock - read superblock.630 * @c: UBIFS file-system description object631 *632 * This function finds, reads and checks the superblock. If an empty UBI volume633 * is being mounted, this function creates default superblock. Returns zero in634 * case of success, and a negative error code in case of failure.635 */636int ubifs_read_superblock(struct ubifs_info *c)637{638 int err, sup_flags;639 struct ubifs_sb_node *sup;640 641 if (c->empty) {642 err = create_default_filesystem(c);643 if (err)644 return err;645 }646 647 sup = ubifs_read_sb_node(c);648 if (IS_ERR(sup))649 return PTR_ERR(sup);650 651 c->sup_node = sup;652 653 c->fmt_version = le32_to_cpu(sup->fmt_version);654 c->ro_compat_version = le32_to_cpu(sup->ro_compat_version);655 656 /*657 * The software supports all previous versions but not future versions,658 * due to the unavailability of time-travelling equipment.659 */660 if (c->fmt_version > UBIFS_FORMAT_VERSION) {661 ubifs_assert(c, !c->ro_media || c->ro_mount);662 if (!c->ro_mount ||663 c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) {664 ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",665 c->fmt_version, c->ro_compat_version,666 UBIFS_FORMAT_VERSION,667 UBIFS_RO_COMPAT_VERSION);668 if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) {669 ubifs_msg(c, "only R/O mounting is possible");670 err = -EROFS;671 } else672 err = -EINVAL;673 goto out;674 }675 676 /*677 * The FS is mounted R/O, and the media format is678 * R/O-compatible with the UBIFS implementation, so we can679 * mount.680 */681 c->rw_incompat = 1;682 }683 684 if (c->fmt_version < 3) {685 ubifs_err(c, "on-flash format version %d is not supported",686 c->fmt_version);687 err = -EINVAL;688 goto out;689 }690 691 switch (sup->key_hash) {692 case UBIFS_KEY_HASH_R5:693 c->key_hash = key_r5_hash;694 c->key_hash_type = UBIFS_KEY_HASH_R5;695 break;696 697 case UBIFS_KEY_HASH_TEST:698 c->key_hash = key_test_hash;699 c->key_hash_type = UBIFS_KEY_HASH_TEST;700 break;701 }702 703 c->key_fmt = sup->key_fmt;704 705 switch (c->key_fmt) {706 case UBIFS_SIMPLE_KEY_FMT:707 c->key_len = UBIFS_SK_LEN;708 break;709 default:710 ubifs_err(c, "unsupported key format");711 err = -EINVAL;712 goto out;713 }714 715 c->leb_cnt = le32_to_cpu(sup->leb_cnt);716 c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);717 c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);718 c->log_lebs = le32_to_cpu(sup->log_lebs);719 c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);720 c->orph_lebs = le32_to_cpu(sup->orph_lebs);721 c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;722 c->fanout = le32_to_cpu(sup->fanout);723 c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);724 c->rp_size = le64_to_cpu(sup->rp_size);725 c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid));726 c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid));727 sup_flags = le32_to_cpu(sup->flags);728 if (!c->mount_opts.override_compr)729 c->default_compr = le16_to_cpu(sup->default_compr);730 731 c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);732 memcpy(&c->uuid, &sup->uuid, 16);733 c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);734 c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);735 c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH);736 c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION);737 738 err = authenticate_sb_node(c, sup);739 if (err)740 goto out;741 742 if ((sup_flags & ~UBIFS_FLG_MASK) != 0) {743 ubifs_err(c, "Unknown feature flags found: %#x",744 sup_flags & ~UBIFS_FLG_MASK);745 err = -EINVAL;746 goto out;747 }748 749 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) {750 ubifs_err(c, "file system contains encrypted files but UBIFS"751 " was built without crypto support.");752 err = -EINVAL;753 goto out;754 }755 756 /* Automatically increase file system size to the maximum size */757 if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {758 int old_leb_cnt = c->leb_cnt;759 760 c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);761 sup->leb_cnt = cpu_to_le32(c->leb_cnt);762 763 c->superblock_need_write = 1;764 765 dbg_mnt("Auto resizing from %d LEBs to %d LEBs",766 old_leb_cnt, c->leb_cnt);767 }768 769 c->log_bytes = (long long)c->log_lebs * c->leb_size;770 c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;771 c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;772 c->lpt_last = c->lpt_first + c->lpt_lebs - 1;773 c->orph_first = c->lpt_last + 1;774 c->orph_last = c->orph_first + c->orph_lebs - 1;775 c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;776 c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;777 c->main_first = c->leb_cnt - c->main_lebs;778 779 err = validate_sb(c, sup);780out:781 return err;782}783 784/**785 * fixup_leb - fixup/unmap an LEB containing free space.786 * @c: UBIFS file-system description object787 * @lnum: the LEB number to fix up788 * @len: number of used bytes in LEB (starting at offset 0)789 *790 * This function reads the contents of the given LEB number @lnum, then fixes791 * it up, so that empty min. I/O units in the end of LEB are actually erased on792 * flash (rather than being just all-0xff real data). If the LEB is completely793 * empty, it is simply unmapped.794 */795static int fixup_leb(struct ubifs_info *c, int lnum, int len)796{797 int err;798 799 ubifs_assert(c, len >= 0);800 ubifs_assert(c, len % c->min_io_size == 0);801 ubifs_assert(c, len < c->leb_size);802 803 if (len == 0) {804 dbg_mnt("unmap empty LEB %d", lnum);805 return ubifs_leb_unmap(c, lnum);806 }807 808 dbg_mnt("fixup LEB %d, data len %d", lnum, len);809 err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1);810 if (err)811 return err;812 813 return ubifs_leb_change(c, lnum, c->sbuf, len);814}815 816/**817 * fixup_free_space - find & remap all LEBs containing free space.818 * @c: UBIFS file-system description object819 *820 * This function walks through all LEBs in the filesystem and fiexes up those821 * containing free/empty space.822 */823static int fixup_free_space(struct ubifs_info *c)824{825 int lnum, err = 0;826 struct ubifs_lprops *lprops;827 828 ubifs_get_lprops(c);829 830 /* Fixup LEBs in the master area */831 for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) {832 err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz);833 if (err)834 goto out;835 }836 837 /* Unmap unused log LEBs */838 lnum = ubifs_next_log_lnum(c, c->lhead_lnum);839 while (lnum != c->ltail_lnum) {840 err = fixup_leb(c, lnum, 0);841 if (err)842 goto out;843 lnum = ubifs_next_log_lnum(c, lnum);844 }845 846 /*847 * Fixup the log head which contains the only a CS node at the848 * beginning.849 */850 err = fixup_leb(c, c->lhead_lnum,851 ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size));852 if (err)853 goto out;854 855 /* Fixup LEBs in the LPT area */856 for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {857 int free = c->ltab[lnum - c->lpt_first].free;858 859 if (free > 0) {860 err = fixup_leb(c, lnum, c->leb_size - free);861 if (err)862 goto out;863 }864 }865 866 /* Unmap LEBs in the orphans area */867 for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {868 err = fixup_leb(c, lnum, 0);869 if (err)870 goto out;871 }872 873 /* Fixup LEBs in the main area */874 for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {875 lprops = ubifs_lpt_lookup(c, lnum);876 if (IS_ERR(lprops)) {877 err = PTR_ERR(lprops);878 goto out;879 }880 881 if (lprops->free > 0) {882 err = fixup_leb(c, lnum, c->leb_size - lprops->free);883 if (err)884 goto out;885 }886 }887 888out:889 ubifs_release_lprops(c);890 return err;891}892 893/**894 * ubifs_fixup_free_space - find & fix all LEBs with free space.895 * @c: UBIFS file-system description object896 *897 * This function fixes up LEBs containing free space on first mount, if the898 * appropriate flag was set when the FS was created. Each LEB with one or more899 * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure900 * the free space is actually erased. E.g., this is necessary for some NAND901 * chips, since the free space may have been programmed like real "0xff" data902 * (generating a non-0xff ECC), causing future writes to the not-really-erased903 * NAND pages to behave badly. After the space is fixed up, the superblock flag904 * is cleared, so that this is skipped for all future mounts.905 */906int ubifs_fixup_free_space(struct ubifs_info *c)907{908 int err;909 struct ubifs_sb_node *sup = c->sup_node;910 911 ubifs_assert(c, c->space_fixup);912 ubifs_assert(c, !c->ro_mount);913 914 ubifs_msg(c, "start fixing up free space");915 916 err = fixup_free_space(c);917 if (err)918 return err;919 920 /* Free-space fixup is no longer required */921 c->space_fixup = 0;922 sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP);923 924 c->superblock_need_write = 1;925 926 ubifs_msg(c, "free space fixup complete");927 return err;928}929 930int ubifs_enable_encryption(struct ubifs_info *c)931{932 int err;933 struct ubifs_sb_node *sup = c->sup_node;934 935 if (!IS_ENABLED(CONFIG_FS_ENCRYPTION))936 return -EOPNOTSUPP;937 938 if (c->encrypted)939 return 0;940 941 if (c->ro_mount || c->ro_media)942 return -EROFS;943 944 if (c->fmt_version < 5) {945 ubifs_err(c, "on-flash format version 5 is needed for encryption");946 return -EINVAL;947 }948 949 sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION);950 951 err = ubifs_write_sb_node(c, sup);952 if (!err)953 c->encrypted = 1;954 955 return err;956}957