/*
* 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/err.h>
#include <linux/stat.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
/*
* removed in barebox
static int create_default_filesystem(struct ubifs_info *c)
*/
/**
* 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);
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);
int authenticated = !!(sup_flags & UBIFS_FLG_AUTHENTICATION);
int hash_algo;
struct digest *digest;
if (!authenticated)
return 0;
if (!ubifs_allow_authenticated_unauthenticated)
return -EPERM;
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;
}
digest = digest_alloc_by_algo(hash_algo);
if (!digest) {
ubifs_err(c, "Cannot allocate hash algo %d",
hash_algo);
return -EINVAL;
}
c->hash_len = digest_length(digest);
return 0;
}
/*
* removed in barebox
int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
*/
/**
* 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) {
ubifs_err(c, "No UBIFS filesystem found\n");
return -EINVAL;
}
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);
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;
}
#ifndef CONFIG_UBIFS_FS_ENCRYPTION
if (c->encrypted && !ubifs_allow_encrypted) {
ubifs_err(c, "file system contains encrypted files but UBIFS"
" was built without crypto support.");
err = -EINVAL;
goto out;
}
#endif
/* 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 {
/* Auto resizing not done in barebox */
}
}
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;
}
/*
* removed in barebox
static int fixup_leb(struct ubifs_info *c, int lnum, int len)
*/
/*
* removed in barebox
static int fixup_free_space(struct ubifs_info *c)
*/
/*
* removed in barebox
int ubifs_fixup_free_space(struct ubifs_info *c)
*/
/*
* removed in barebox
int ubifs_enable_encryption(struct ubifs_info *c)
*/
