/* * This file is part of UBIFS. * * Copyright (C) 2006-2008 Nokia Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 51 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * 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/random.h> #include <linux/math64.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 /** * 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; long long tmp64, main_bytes; __le64 tmp_le64; /* 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; #ifdef CONFIG_UBIFS_FS_DEBUG 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; #endif 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); 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; /* Create default superblock */ tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size); sup = kzalloc(tmp, GFP_KERNEL); if (!sup) return -ENOMEM; tmp64 = (long long)max_buds * c->leb_size; if (big_lpt) sup_flags |= UBIFS_FLG_BIGLPT; 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_FORMAT_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(UBIFS_COMPR_LZO); 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); err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0, UBI_LONGTERM); kfree(sup); if (err) return err; dbg_gen("default superblock created at LEB 0:0"); /* Create default master node */ mst = kzalloc(c->mst_node_alsz, GFP_KERNEL); if (!mst) return -ENOMEM; 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); /* 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 = (c->main_lebs - 1) * c->dark_wm; mst->total_dark = cpu_to_le64(tmp64); mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ); err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0, UBI_UNKNOWN); if (err) { kfree(mst); return err; } err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 0, UBI_UNKNOWN); kfree(mst); if (err) return err; dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM); /* Create the root indexing node */ tmp = ubifs_idx_node_sz(c, 1); idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL); if (!idx) return -ENOMEM; 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); err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0, UBI_UNKNOWN); kfree(idx); if (err) return err; dbg_gen("default root indexing node created LEB %d:0", main_first + DEFAULT_IDX_LEB); /* Create default root inode */ tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size); ino = kzalloc(tmp, GFP_KERNEL); if (!ino) return -ENOMEM; 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); tmp_le64 = cpu_to_le64(CURRENT_TIME_SEC.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); err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ, main_first + DEFAULT_DATA_LEB, 0, UBI_UNKNOWN); kfree(ino); if (err) return err; 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. */ tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size); cs = kzalloc(tmp, GFP_KERNEL); if (!cs) return -ENOMEM; cs->ch.node_type = UBIFS_CS_NODE; err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM, 0, UBI_UNKNOWN); kfree(cs); ubifs_msg("default file-system created"); return 0; } /** * 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("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("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("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("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) { err = 7; goto failed; } if (c->max_bud_bytes < (long long)c->leb_size * UBIFS_MIN_BUD_LEBS || c->max_bud_bytes > (long long)c->leb_size * c->main_lebs) { err = 8; 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 < 0 || c->default_compr >= UBIFS_COMPR_TYPES_CNT) { err = 13; goto failed; } max_bytes = c->main_lebs * (long long)c->leb_size; 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; } return 0; failed: ubifs_err("bad superblock, error %d", err); dbg_dump_node(c, sup); 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. */ 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; } /** * 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); ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1); return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len, UBI_LONGTERM); } /** * 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->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) { struct super_block *sb = c->vfs_sb; int mounting_ro = sb->s_flags & MS_RDONLY; ubifs_assert(!c->ro_media || mounting_ro); if (!mounting_ro || c->ro_compat_version > UBIFS_RO_COMPAT_VERSION) { ubifs_err("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("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("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("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 = le32_to_cpu(sup->rp_uid); c->rp_gid = 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); /* Automatically increase file system size to the maximum size */ c->old_leb_cnt = c->leb_cnt; if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) { c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size); if (c->vfs_sb->s_flags & MS_RDONLY) dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs", c->old_leb_cnt, c->leb_cnt); else { dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs", c->old_leb_cnt, c->leb_cnt); sup->leb_cnt = cpu_to_le32(c->leb_cnt); err = ubifs_write_sb_node(c, sup); if (err) goto out; c->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: kfree(sup); return err; }