--- /dev/null
+/*
+ * 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;
+}
Code Review / kvmfornfv.git / blobdiff