diff options
Diffstat (limited to 'kernel/fs/ubifs/sb.c')
| -rw-r--r-- | kernel/fs/ubifs/sb.c | 809 |
1 files changed, 809 insertions, 0 deletions
diff --git a/kernel/fs/ubifs/sb.c b/kernel/fs/ubifs/sb.c new file mode 100644 index 000000000..f4fbc7b6b --- /dev/null +++ b/kernel/fs/ubifs/sb.c @@ -0,0 +1,809 @@ +/* + * 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; + 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); + 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); + 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 = ((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); + + err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0); + if (err) { + kfree(mst); + return err; + } + err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, + 0); + 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); + 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); + 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); + kfree(cs); + if (err) + return err; + + ubifs_msg(c, "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(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; + } + + return 0; + +failed: + ubifs_err(c, "bad superblock, error %d", err); + ubifs_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. Note, the user of this function is responsible of kfree()'ing the + * returned superblock buffer. + */ +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); +} + +/** + * 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) { + ubifs_assert(!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); + + /* 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->ro_mount) + 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; +} + +/** + * 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(len >= 0); + ubifs_assert(len % c->min_io_size == 0); + ubifs_assert(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; + + ubifs_assert(c->space_fixup); + ubifs_assert(!c->ro_mount); + + ubifs_msg(c, "start fixing up free space"); + + err = fixup_free_space(c); + if (err) + return err; + + sup = ubifs_read_sb_node(c); + if (IS_ERR(sup)) + return PTR_ERR(sup); + + /* Free-space fixup is no longer required */ + c->space_fixup = 0; + sup->flags &= cpu_to_le32(~UBIFS_FLG_SPACE_FIXUP); + + err = ubifs_write_sb_node(c, sup); + kfree(sup); + if (err) + return err; + + ubifs_msg(c, "free space fixup complete"); + return err; +} |