// SPDX-License-Identifier: GPL-2.0-only /* * This file is part of UBIFS. * * Copyright (C) 2006-2008 Nokia Corporation. * * Authors: Artem Bityutskiy (Битюцкий Артём) * Adrian Hunter */ /* * This file implements UBIFS superblock. The superblock is stored at the first * LEB of the volume and is never changed by UBIFS. Only user-space tools may * change it. The superblock node mostly contains geometry information. */ #include "ubifs.h" #include <linux/slab.h> #include <linux/math64.h> #include <linux/uuid.h> /* * Default journal size in logical eraseblocks as a percent of total * flash size. */ #define DEFAULT_JNL_PERCENT 5 /* Default maximum journal size in bytes */ #define DEFAULT_MAX_JNL (32*1024*1024) /* Default indexing tree fanout */ #define DEFAULT_FANOUT 8 /* Default number of data journal heads */ #define DEFAULT_JHEADS_CNT 1 /* Default positions of different LEBs in the main area */ #define DEFAULT_IDX_LEB 0 #define DEFAULT_DATA_LEB 1 #define DEFAULT_GC_LEB 2 /* Default number of LEB numbers in LPT's save table */ #define DEFAULT_LSAVE_CNT 256 /* Default reserved pool size as a percent of maximum free space */ #define DEFAULT_RP_PERCENT 5 /* The default maximum size of reserved pool in bytes */ #define DEFAULT_MAX_RP_SIZE (5*1024*1024) /* Default time granularity in nanoseconds */ #define DEFAULT_TIME_GRAN 1000000000 static int get_default_compressor(struct ubifs_info *c) { if (ubifs_compr_present(c, UBIFS_COMPR_ZSTD)) return UBIFS_COMPR_ZSTD; if (ubifs_compr_present(c, UBIFS_COMPR_LZO)) return UBIFS_COMPR_LZO; if (ubifs_compr_present(c, UBIFS_COMPR_ZLIB)) return UBIFS_COMPR_ZLIB; return UBIFS_COMPR_NONE; } /** * create_default_filesystem - format empty UBI volume. * @c: UBIFS file-system description object * * This function creates default empty file-system. Returns zero in case of * success and a negative error code in case of failure. */ static int create_default_filesystem(struct ubifs_info *c) { struct ubifs_sb_node *sup; struct ubifs_mst_node *mst; struct ubifs_idx_node *idx; struct ubifs_branch *br; struct ubifs_ino_node *ino; struct ubifs_cs_node *cs; union ubifs_key key; int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first; int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0; int min_leb_cnt = UBIFS_MIN_LEB_CNT; int idx_node_size; long long tmp64, main_bytes; __le64 tmp_le64; struct timespec64 ts; u8 hash[UBIFS_HASH_ARR_SZ]; u8 hash_lpt[UBIFS_HASH_ARR_SZ]; /* Some functions called from here depend on the @c->key_len filed */ c->key_len = UBIFS_SK_LEN; /* * First of all, we have to calculate default file-system geometry - * log size, journal size, etc. */ if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT) /* We can first multiply then divide and have no overflow */ jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100; else jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT; if (jnl_lebs < UBIFS_MIN_JNL_LEBS) jnl_lebs = UBIFS_MIN_JNL_LEBS; if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL) jnl_lebs = DEFAULT_MAX_JNL / c->leb_size; /* * The log should be large enough to fit reference nodes for all bud * LEBs. Because buds do not have to start from the beginning of LEBs * (half of the LEB may contain committed data), the log should * generally be larger, make it twice as large. */ tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1; log_lebs = tmp / c->leb_size; /* Plus one LEB reserved for commit */ log_lebs += 1; if (c->leb_cnt - min_leb_cnt > 8) { /* And some extra space to allow writes while committing */ log_lebs += 1; min_leb_cnt += 1; } max_buds = jnl_lebs - log_lebs; if (max_buds < UBIFS_MIN_BUD_LEBS) max_buds = UBIFS_MIN_BUD_LEBS; /* * Orphan nodes are stored in a separate area. One node can store a lot * of orphan inode numbers, but when new orphan comes we just add a new * orphan node. At some point the nodes are consolidated into one * orphan node. */ orph_lebs = UBIFS_MIN_ORPH_LEBS; if (c->leb_cnt - min_leb_cnt > 1) /* * For debugging purposes it is better to have at least 2 * orphan LEBs, because the orphan subsystem would need to do * consolidations and would be stressed more. */ orph_lebs += 1; main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs; main_lebs -= orph_lebs; lpt_first = UBIFS_LOG_LNUM + log_lebs; c->lsave_cnt = DEFAULT_LSAVE_CNT; c->max_leb_cnt = c->leb_cnt; err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs, &big_lpt, hash_lpt); if (err) return err; dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first, lpt_first + lpt_lebs - 1); main_first = c->leb_cnt - main_lebs; sup = kzalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_KERNEL); mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); idx_node_size = ubifs_idx_node_sz(c, 1); idx = kzalloc(ALIGN(idx_node_size, c->min_io_size), GFP_KERNEL); ino = kzalloc(ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size), GFP_KERNEL); cs = kzalloc(ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size), GFP_KERNEL); if (!sup || !mst || !idx || !ino || !cs) { err = -ENOMEM; goto out; } /* Create default superblock */ tmp64 = (long long)max_buds * c->leb_size; if (big_lpt) sup_flags |= UBIFS_FLG_BIGLPT; if (ubifs_default_version > 4) sup_flags |= UBIFS_FLG_DOUBLE_HASH; if (ubifs_authenticated(c)) { sup_flags |= UBIFS_FLG_AUTHENTICATION; sup->hash_algo = cpu_to_le16(c->auth_hash_algo); err = ubifs_hmac_wkm(c, sup->hmac_wkm); if (err) goto out; } else { sup->hash_algo = cpu_to_le16(0xffff); } sup->ch.node_type = UBIFS_SB_NODE; sup->key_hash = UBIFS_KEY_HASH_R5; sup->flags = cpu_to_le32(sup_flags); sup->min_io_size = cpu_to_le32(c->min_io_size); sup->leb_size = cpu_to_le32(c->leb_size); sup->leb_cnt = cpu_to_le32(c->leb_cnt); sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt); sup->max_bud_bytes = cpu_to_le64(tmp64); sup->log_lebs = cpu_to_le32(log_lebs); sup->lpt_lebs = cpu_to_le32(lpt_lebs); sup->orph_lebs = cpu_to_le32(orph_lebs); sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT); sup->fanout = cpu_to_le32(DEFAULT_FANOUT); sup->lsave_cnt = cpu_to_le32(c->lsave_cnt); sup->fmt_version = cpu_to_le32(ubifs_default_version); sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN); if (c->mount_opts.override_compr) sup->default_compr = cpu_to_le16(c->mount_opts.compr_type); else sup->default_compr = cpu_to_le16(get_default_compressor(c)); generate_random_uuid(sup->uuid); main_bytes = (long long)main_lebs * c->leb_size; tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100); if (tmp64 > DEFAULT_MAX_RP_SIZE) tmp64 = DEFAULT_MAX_RP_SIZE; sup->rp_size = cpu_to_le64(tmp64); sup->ro_compat_version = cpu_to_le32(UBIFS_RO_COMPAT_VERSION); dbg_gen("default superblock created at LEB 0:0"); /* Create default master node */ mst->ch.node_type = UBIFS_MST_NODE; mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM); mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO); mst->cmt_no = 0; mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); mst->root_offs = 0; tmp = ubifs_idx_node_sz(c, 1); mst->root_len = cpu_to_le32(tmp); mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB); mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB); mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size)); mst->index_size = cpu_to_le64(ALIGN(tmp, 8)); mst->lpt_lnum = cpu_to_le32(c->lpt_lnum); mst->lpt_offs = cpu_to_le32(c->lpt_offs); mst->nhead_lnum = cpu_to_le32(c->nhead_lnum); mst->nhead_offs = cpu_to_le32(c->nhead_offs); mst->ltab_lnum = cpu_to_le32(c->ltab_lnum); mst->ltab_offs = cpu_to_le32(c->ltab_offs); mst->lsave_lnum = cpu_to_le32(c->lsave_lnum); mst->lsave_offs = cpu_to_le32(c->lsave_offs); mst->lscan_lnum = cpu_to_le32(main_first); mst->empty_lebs = cpu_to_le32(main_lebs - 2); mst->idx_lebs = cpu_to_le32(1); mst->leb_cnt = cpu_to_le32(c->leb_cnt); ubifs_copy_hash(c, hash_lpt, mst->hash_lpt); /* Calculate lprops statistics */ tmp64 = main_bytes; tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); mst->total_free = cpu_to_le64(tmp64); tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size); ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) - UBIFS_INO_NODE_SZ; tmp64 += ino_waste; tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8); mst->total_dirty = cpu_to_le64(tmp64); /* The indexing LEB does not contribute to dark space */ tmp64 = ((long long)(c->main_lebs - 1) * c->dark_wm); mst->total_dark = cpu_to_le64(tmp64); mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM); /* Create the root indexing node */ c->key_fmt = UBIFS_SIMPLE_KEY_FMT; c->key_hash = key_r5_hash; idx->ch.node_type = UBIFS_IDX_NODE; idx->child_cnt = cpu_to_le16(1); ino_key_init(c, &key, UBIFS_ROOT_INO); br = ubifs_idx_branch(c, idx, 0); key_write_idx(c, &key, &br->key); br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB); br->len = cpu_to_le32(UBIFS_INO_NODE_SZ); dbg_gen("default root indexing node created LEB %d:0", main_first + DEFAULT_IDX_LEB); /* Create default root inode */ ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO); ino->ch.node_type = UBIFS_INO_NODE; ino->creat_sqnum = cpu_to_le64(++c->max_sqnum); ino->nlink = cpu_to_le32(2); ktime_get_coarse_real_ts64(&ts); tmp_le64 = cpu_to_le64(ts.tv_sec); ino->atime_sec = tmp_le64; ino->ctime_sec = tmp_le64; ino->mtime_sec = tmp_le64; ino->atime_nsec = 0; ino->ctime_nsec = 0; ino->mtime_nsec = 0; ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO); ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ); /* Set compression enabled by default */ ino->flags = cpu_to_le32(UBIFS_COMPR_FL); dbg_gen("root inode created at LEB %d:0", main_first + DEFAULT_DATA_LEB); /* * The first node in the log has to be the commit start node. This is * always the case during normal file-system operation. Write a fake * commit start node to the log. */ cs->ch.node_type = UBIFS_CS_NODE; err = ubifs_write_node_hmac(c, sup, UBIFS_SB_NODE_SZ, 0, 0, offsetof(struct ubifs_sb_node, hmac)); if (err) goto out; err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ, main_first + DEFAULT_DATA_LEB, 0); if (err) goto out; ubifs_node_calc_hash(c, ino, hash); ubifs_copy_hash(c, hash, ubifs_branch_hash(c, br)); err = ubifs_write_node(c, idx, idx_node_size, main_first + DEFAULT_IDX_LEB, 0); if (err) goto out; ubifs_node_calc_hash(c, idx, hash); ubifs_copy_hash(c, hash, mst->hash_root_idx); err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0, offsetof(struct ubifs_mst_node, hmac)); if (err) goto out; err = ubifs_write_node_hmac(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 0, offsetof(struct ubifs_mst_node, hmac)); if (err) goto out; err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0); if (err) goto out; ubifs_msg(c, "default file-system created"); err = 0; out: kfree(sup); kfree(mst); kfree(idx); kfree(ino); kfree(cs); return err; } /** * validate_sb - validate superblock node. * @c: UBIFS file-system description object * @sup: superblock node * * This function validates superblock node @sup. Since most of data was read * from the superblock and stored in @c, the function validates fields in @c * instead. Returns zero in case of success and %-EINVAL in case of validation * failure. */ static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup) { long long max_bytes; int err = 1, min_leb_cnt; if (!c->key_hash) { err = 2; goto failed; } if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) { err = 3; goto failed; } if (le32_to_cpu(sup->min_io_size) != c->min_io_size) { ubifs_err(c, "min. I/O unit mismatch: %d in superblock, %d real", le32_to_cpu(sup->min_io_size), c->min_io_size); goto failed; } if (le32_to_cpu(sup->leb_size) != c->leb_size) { ubifs_err(c, "LEB size mismatch: %d in superblock, %d real", le32_to_cpu(sup->leb_size), c->leb_size); goto failed; } if (c->log_lebs < UBIFS_MIN_LOG_LEBS || c->lpt_lebs < UBIFS_MIN_LPT_LEBS || c->orph_lebs < UBIFS_MIN_ORPH_LEBS || c->main_lebs < UBIFS_MIN_MAIN_LEBS) { err = 4; goto failed; } /* * Calculate minimum allowed amount of main area LEBs. This is very * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we * have just read from the superblock. */ min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs; min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6; if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) { ubifs_err(c, "bad LEB count: %d in superblock, %d on UBI volume, %d minimum required", c->leb_cnt, c->vi.size, min_leb_cnt); goto failed; } if (c->max_leb_cnt < c->leb_cnt) { ubifs_err(c, "max. LEB count %d less than LEB count %d", c->max_leb_cnt, c->leb_cnt); goto failed; } if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) { ubifs_err(c, "too few main LEBs count %d, must be at least %d", c->main_lebs, UBIFS_MIN_MAIN_LEBS); goto failed; } max_bytes = (long long)c->leb_size * UBIFS_MIN_BUD_LEBS; if (c->max_bud_bytes < max_bytes) { ubifs_err(c, "too small journal (%lld bytes), must be at least %lld bytes", c->max_bud_bytes, max_bytes); goto failed; } max_bytes = (long long)c->leb_size * c->main_lebs; if (c->max_bud_bytes > max_bytes) { ubifs_err(c, "too large journal size (%lld bytes), only %lld bytes available in the main area", c->max_bud_bytes, max_bytes); goto failed; } if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 || c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) { err = 9; goto failed; } if (c->fanout < UBIFS_MIN_FANOUT || ubifs_idx_node_sz(c, c->fanout) > c->leb_size) { err = 10; goto failed; } if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT && c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - c->log_lebs - c->lpt_lebs - c->orph_lebs)) { err = 11; goto failed; } if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs + c->orph_lebs + c->main_lebs != c->leb_cnt) { err = 12; goto failed; } if (c->default_compr >= UBIFS_COMPR_TYPES_CNT) { err = 13; goto failed; } if (c->rp_size < 0 || max_bytes < c->rp_size) { err = 14; goto failed; } if (le32_to_cpu(sup->time_gran) > 1000000000 || le32_to_cpu(sup->time_gran) < 1) { err = 15; goto failed; } if (!c->double_hash && c->fmt_version >= 5) { err = 16; goto failed; } if (c->encrypted && c->fmt_version < 5) { err = 17; goto failed; } return 0; failed: ubifs_err(c, "bad superblock, error %d", err); ubifs_dump_node(c, sup, ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size)); return -EINVAL; } /** * ubifs_read_sb_node - read superblock node. * @c: UBIFS file-system description object * * This function returns a pointer to the superblock node or a negative error * code. Note, the user of this function is responsible of kfree()'ing the * returned superblock buffer. */ static struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c) { struct ubifs_sb_node *sup; int err; sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS); if (!sup) return ERR_PTR(-ENOMEM); err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ, UBIFS_SB_LNUM, 0); if (err) { kfree(sup); return ERR_PTR(err); } return sup; } static int authenticate_sb_node(struct ubifs_info *c, const struct ubifs_sb_node *sup) { unsigned int sup_flags = le32_to_cpu(sup->flags); u8 hmac_wkm[UBIFS_HMAC_ARR_SZ]; int authenticated = !!(sup_flags & UBIFS_FLG_AUTHENTICATION); int hash_algo; int err; if (c->authenticated && !authenticated) { ubifs_err(c, "authenticated FS forced, but found FS without authentication"); return -EINVAL; } if (!c->authenticated && authenticated) { ubifs_err(c, "authenticated FS found, but no key given"); return -EINVAL; } ubifs_msg(c, "Mounting in %sauthenticated mode", c->authenticated ? "" : "un"); if (!c->authenticated) return 0; if (!IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) return -EOPNOTSUPP; hash_algo = le16_to_cpu(sup->hash_algo); if (hash_algo >= HASH_ALGO__LAST) { ubifs_err(c, "superblock uses unknown hash algo %d", hash_algo); return -EINVAL; } if (strcmp(hash_algo_name[hash_algo], c->auth_hash_name)) { ubifs_err(c, "This filesystem uses %s for hashing," " but %s is specified", hash_algo_name[hash_algo], c->auth_hash_name); return -EINVAL; } /* * The super block node can either be authenticated by a HMAC or * by a signature in a ubifs_sig_node directly following the * super block node to support offline image creation. */ if (ubifs_hmac_zero(c, sup->hmac)) { err = ubifs_sb_verify_signature(c, sup); } else { err = ubifs_hmac_wkm(c, hmac_wkm); if (err) return err; if (ubifs_check_hmac(c, hmac_wkm, sup->hmac_wkm)) { ubifs_err(c, "provided key does not fit"); return -ENOKEY; } err = ubifs_node_verify_hmac(c, sup, sizeof(*sup), offsetof(struct ubifs_sb_node, hmac)); } if (err) ubifs_err(c, "Failed to authenticate superblock: %d", err); return err; } /** * ubifs_write_sb_node - write superblock node. * @c: UBIFS file-system description object * @sup: superblock node read with 'ubifs_read_sb_node()' * * This function returns %0 on success and a negative error code on failure. */ int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup) { int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); int err; err = ubifs_prepare_node_hmac(c, sup, UBIFS_SB_NODE_SZ, offsetof(struct ubifs_sb_node, hmac), 1); if (err) return err; return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len); } /** * ubifs_read_superblock - read superblock. * @c: UBIFS file-system description object * * This function finds, reads and checks the superblock. If an empty UBI volume * is being mounted, this function creates default superblock. Returns zero in * case of success, and a negative error code in case of failure. */ int ubifs_read_superblock(struct ubifs_info *c) { int err, sup_flags; struct ubifs_sb_node *sup; if (c->empty) { err = create_default_filesystem(c); if (err) return err; } sup = ubifs_read_sb_node(c); if (IS_ERR(sup)) return PTR_ERR(sup); c->sup_node = sup; c->fmt_version = le32_to_cpu(sup->fmt_version); c->ro_compat_version = le32_to_cpu(sup->ro_compat_version); /* * The software supports all previous versions but not future versions, * due to the unavailability of time-travelling equipment. */ if (c->fmt_version > UBIFS_FORMAT_VERSION) { ubifs_assert(c, !c->ro_media || c->ro_mount); if (!c->ro_mount || c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { ubifs_err(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d", c->fmt_version, c->ro_compat_version, UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION); if (c->ro_compat_version <= UBIFS_RO_COMPAT_VERSION) { ubifs_msg(c, "only R/O mounting is possible"); err = -EROFS; } else err = -EINVAL; goto out; } /* * The FS is mounted R/O, and the media format is * R/O-compatible with the UBIFS implementation, so we can * mount. */ c->rw_incompat = 1; } if (c->fmt_version < 3) { ubifs_err(c, "on-flash format version %d is not supported", c->fmt_version); err = -EINVAL; goto out; } switch (sup->key_hash) { case UBIFS_KEY_HASH_R5: c->key_hash = key_r5_hash; c->key_hash_type = UBIFS_KEY_HASH_R5; break; case UBIFS_KEY_HASH_TEST: c->key_hash = key_test_hash; c->key_hash_type = UBIFS_KEY_HASH_TEST; break; } c->key_fmt = sup->key_fmt; switch (c->key_fmt) { case UBIFS_SIMPLE_KEY_FMT: c->key_len = UBIFS_SK_LEN; break; default: ubifs_err(c, "unsupported key format"); err = -EINVAL; goto out; } c->leb_cnt = le32_to_cpu(sup->leb_cnt); c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt); c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes); c->log_lebs = le32_to_cpu(sup->log_lebs); c->lpt_lebs = le32_to_cpu(sup->lpt_lebs); c->orph_lebs = le32_to_cpu(sup->orph_lebs); c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT; c->fanout = le32_to_cpu(sup->fanout); c->lsave_cnt = le32_to_cpu(sup->lsave_cnt); c->rp_size = le64_to_cpu(sup->rp_size); c->rp_uid = make_kuid(&init_user_ns, le32_to_cpu(sup->rp_uid)); c->rp_gid = make_kgid(&init_user_ns, le32_to_cpu(sup->rp_gid)); sup_flags = le32_to_cpu(sup->flags); if (!c->mount_opts.override_compr) c->default_compr = le16_to_cpu(sup->default_compr); c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran); memcpy(&c->uuid, &sup->uuid, 16); c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT); c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); err = authenticate_sb_node(c, sup); if (err) goto out; if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { ubifs_err(c, "Unknown feature flags found: %#x", sup_flags & ~UBIFS_FLG_MASK); err = -EINVAL; goto out; } if (!IS_ENABLED(CONFIG_FS_ENCRYPTION) && c->encrypted) { ubifs_err(c, "file system contains encrypted files but UBIFS" " was built without crypto support."); err = -EINVAL; goto out; } /* Automatically increase file system size to the maximum size */ if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { int old_leb_cnt = c->leb_cnt; c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); sup->leb_cnt = cpu_to_le32(c->leb_cnt); c->superblock_need_write = 1; dbg_mnt("Auto resizing from %d LEBs to %d LEBs", old_leb_cnt, c->leb_cnt); } c->log_bytes = (long long)c->log_lebs * c->leb_size; c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1; c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs; c->lpt_last = c->lpt_first + c->lpt_lebs - 1; c->orph_first = c->lpt_last + 1; c->orph_last = c->orph_first + c->orph_lebs - 1; c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS; c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs; c->main_first = c->leb_cnt - c->main_lebs; err = validate_sb(c, sup); out: return err; } /** * fixup_leb - fixup/unmap an LEB containing free space. * @c: UBIFS file-system description object * @lnum: the LEB number to fix up * @len: number of used bytes in LEB (starting at offset 0) * * This function reads the contents of the given LEB number @lnum, then fixes * it up, so that empty min. I/O units in the end of LEB are actually erased on * flash (rather than being just all-0xff real data). If the LEB is completely * empty, it is simply unmapped. */ static int fixup_leb(struct ubifs_info *c, int lnum, int len) { int err; ubifs_assert(c, len >= 0); ubifs_assert(c, len % c->min_io_size == 0); ubifs_assert(c, len < c->leb_size); if (len == 0) { dbg_mnt("unmap empty LEB %d", lnum); return ubifs_leb_unmap(c, lnum); } dbg_mnt("fixup LEB %d, data len %d", lnum, len); err = ubifs_leb_read(c, lnum, c->sbuf, 0, len, 1); if (err) return err; return ubifs_leb_change(c, lnum, c->sbuf, len); } /** * fixup_free_space - find & remap all LEBs containing free space. * @c: UBIFS file-system description object * * This function walks through all LEBs in the filesystem and fiexes up those * containing free/empty space. */ static int fixup_free_space(struct ubifs_info *c) { int lnum, err = 0; struct ubifs_lprops *lprops; ubifs_get_lprops(c); /* Fixup LEBs in the master area */ for (lnum = UBIFS_MST_LNUM; lnum < UBIFS_LOG_LNUM; lnum++) { err = fixup_leb(c, lnum, c->mst_offs + c->mst_node_alsz); if (err) goto out; } /* Unmap unused log LEBs */ lnum = ubifs_next_log_lnum(c, c->lhead_lnum); while (lnum != c->ltail_lnum) { err = fixup_leb(c, lnum, 0); if (err) goto out; lnum = ubifs_next_log_lnum(c, lnum); } /* * Fixup the log head which contains the only a CS node at the * beginning. */ err = fixup_leb(c, c->lhead_lnum, ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size)); if (err) goto out; /* Fixup LEBs in the LPT area */ for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { int free = c->ltab[lnum - c->lpt_first].free; if (free > 0) { err = fixup_leb(c, lnum, c->leb_size - free); if (err) goto out; } } /* Unmap LEBs in the orphans area */ for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) { err = fixup_leb(c, lnum, 0); if (err) goto out; } /* Fixup LEBs in the main area */ for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) { lprops = ubifs_lpt_lookup(c, lnum); if (IS_ERR(lprops)) { err = PTR_ERR(lprops); goto out; } if (lprops->free > 0) { err = fixup_leb(c, lnum, c->leb_size - lprops->free); if (err) goto out; } } out: ubifs_release_lprops(c); return err; } /** * ubifs_fixup_free_space - find & fix all LEBs with free space. * @c: UBIFS file-system description object * * This function fixes up LEBs containing free space on first mount, if the * appropriate flag was set when the FS was created. Each LEB with one or more * empty min. I/O unit (i.e. free-space-count > 0) is re-written, to make sure * the free space is actually erased. E.g., this is necessary for some NAND * chips, since the free space may have been programmed like real "0xff" data * (generating a non-0xff ECC), causing future writes to the not-really-erased * NAND pages to behave badly. After the space is fixed up, the superblock flag * is cleared, so that this is skipped for all future mounts. */ int ubifs_fixup_free_space(struct ubifs_info *c) { int err; struct ubifs_sb_node *sup = c->sup_node; ubifs_assert(c, c->space_fixup); ubifs_assert(c, !c->ro_mount); ubifs_msg(c, "start fixing up free space"); err = fixup_free_space(c); if (err) return err; /* Free-space fixup is no longer required */ c->space_fixup = 0; sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); c->superblock_need_write = 1; ubifs_msg(c, "free space fixup complete"); return err; } int ubifs_enable_encryption(struct ubifs_info *c) { int err; struct ubifs_sb_node *sup = c->sup_node; if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) return -EOPNOTSUPP; if (c->encrypted) return 0; if (c->ro_mount || c->ro_media) return -EROFS; if (c->fmt_version < 5) { ubifs_err(c, "on-flash format version 5 is needed for encryption"); return -EINVAL; } sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION); err = ubifs_write_sb_node(c, sup); if (!err) c->encrypted = 1; return err; }