1 files changed, 629 insertions, 0 deletions

diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
new file mode 100644
index 000000000000..2bf753b38889
--- /dev/null
+++ b/fs/ubifs/sb.c
@@ -0,0 +1,629 @@
+/*
+ * 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/random.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;
+        uint64_t tmp64, main_bytes;
+
+        /* 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 = (uint64_t)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->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
+        sup->time_gran     = cpu_to_le32(DEFAULT_TIME_GRAN);
+
+        generate_random_uuid(sup->uuid);
+
+        main_bytes = (uint64_t)main_lebs * c->leb_size;
+        tmp64 = main_bytes * DEFAULT_RP_PERCENT;
+        do_div(tmp64, 100);
+        if (tmp64 > DEFAULT_MAX_RP_SIZE)
+                tmp64 = DEFAULT_MAX_RP_SIZE;
+        sup->rp_size = cpu_to_le64(tmp64);
+
+        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 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
+        ino->atime_sec   = tmp;
+        ino->ctime_sec   = tmp;
+        ino->mtime_sec   = tmp;
+        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);
+
+        /*
+         * The software supports all previous versions but not future versions,
+         * due to the unavailability of time-travelling equipment.
+         */
+        c->fmt_version = le32_to_cpu(sup->fmt_version);
+        if (c->fmt_version > UBIFS_FORMAT_VERSION) {
+                ubifs_err("on-flash format version is %d, but software only "
+                          "supports up to version %d", c->fmt_version,
+                          UBIFS_FORMAT_VERSION);
+                err = -EINVAL;
+                goto out;
+        }
+
+        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->default_compr = le16_to_cpu(sup->default_compr);
+        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);
+
+        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;
+        c->report_rp_size = ubifs_reported_space(c, c->rp_size);
+
+        err = validate_sb(c, sup);
+out:
+        kfree(sup);
+        return err;
+}