make_ext4fs/ext4_utils.c
Jo-Philipp Wich 828ec043d2 Allow specifying reserved blocks percentage
Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
2015-04-08 07:51:39 +02:00

536 lines
15 KiB
C

/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "ext4_utils.h"
#include "uuid.h"
#include "allocate.h"
#include "indirect.h"
#include "extent.h"
#include <sparse/sparse.h>
#include <fcntl.h>
#include <inttypes.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stddef.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/ioctl.h>
#if defined(__linux__)
#include <linux/fs.h>
#elif defined(__APPLE__) && defined(__MACH__)
#include <sys/disk.h>
#endif
int force = 0;
struct fs_info info;
struct fs_aux_info aux_info;
struct sparse_file *ext4_sparse_file;
jmp_buf setjmp_env;
/* returns 1 if a is a power of b */
static int is_power_of(int a, int b)
{
while (a > b) {
if (a % b)
return 0;
a /= b;
}
return (a == b) ? 1 : 0;
}
int bitmap_get_bit(u8 *bitmap, u32 bit)
{
if (bitmap[bit / 8] & (1 << (bit % 8)))
return 1;
return 0;
}
void bitmap_clear_bit(u8 *bitmap, u32 bit)
{
bitmap[bit / 8] &= ~(1 << (bit % 8));
return;
}
/* Returns 1 if the bg contains a backup superblock. On filesystems with
the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
and 7 have backup superblocks. Otherwise, all block groups have backup
superblocks */
int ext4_bg_has_super_block(int bg)
{
/* Without sparse_super, every block group has a superblock */
if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER))
return 1;
if (bg == 0 || bg == 1)
return 1;
if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7))
return 1;
return 0;
}
/* Function to read the primary superblock */
void read_sb(int fd, struct ext4_super_block *sb)
{
off64_t ret;
ret = lseek64(fd, 1024, SEEK_SET);
if (ret < 0)
critical_error_errno("failed to seek to superblock");
ret = read(fd, sb, sizeof(*sb));
if (ret < 0)
critical_error_errno("failed to read superblock");
if (ret != sizeof(*sb))
critical_error("failed to read all of superblock");
}
/* Function to write a primary or backup superblock at a given offset */
void write_sb(int fd, unsigned long long offset, struct ext4_super_block *sb)
{
off64_t ret;
ret = lseek64(fd, offset, SEEK_SET);
if (ret < 0)
critical_error_errno("failed to seek to superblock");
ret = write(fd, sb, sizeof(*sb));
if (ret < 0)
critical_error_errno("failed to write superblock");
if (ret != sizeof(*sb))
critical_error("failed to write all of superblock");
}
/* Write the filesystem image to a file */
void write_ext4_image(int fd, int gz, int sparse, int crc)
{
sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc);
}
/* Compute the rest of the parameters of the filesystem from the basic info */
void ext4_create_fs_aux_info()
{
aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
aux_info.len_blocks = info.len / info.block_size;
aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
info.block_size);
aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
info.blocks_per_group);
aux_info.blocks_per_ind = info.block_size / sizeof(u32);
aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
aux_info.bg_desc_blocks =
DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
info.block_size);
aux_info.default_i_flags = EXT4_NOATIME_FL;
u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
u32 last_header_size = 2 + aux_info.inode_table_blocks;
if (ext4_bg_has_super_block(aux_info.groups - 1))
last_header_size += 1 + aux_info.bg_desc_blocks +
info.bg_desc_reserve_blocks;
if (last_group_size > 0 && last_group_size < last_header_size) {
aux_info.groups--;
aux_info.len_blocks -= last_group_size;
}
aux_info.sb = calloc(info.block_size, 1);
/* Alloc an array to hold the pointers to the backup superblocks */
aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
if (!aux_info.sb)
critical_error_errno("calloc");
aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
if (!aux_info.bg_desc)
critical_error_errno("calloc");
aux_info.xattrs = NULL;
}
void ext4_free_fs_aux_info()
{
unsigned int i;
for (i=0; i<aux_info.groups; i++) {
if (aux_info.backup_sb[i])
free(aux_info.backup_sb[i]);
}
free(aux_info.sb);
free(aux_info.bg_desc);
}
/* Fill in the superblock memory buffer based on the filesystem parameters */
void ext4_fill_in_sb()
{
unsigned int i;
struct ext4_super_block *sb = aux_info.sb;
sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
sb->s_blocks_count_lo = aux_info.len_blocks;
sb->s_r_blocks_count_lo = (aux_info.len_blocks / 100) * info.reserve_pcnt;
sb->s_free_blocks_count_lo = 0;
sb->s_free_inodes_count = 0;
sb->s_first_data_block = aux_info.first_data_block;
sb->s_log_block_size = log_2(info.block_size / 1024);
sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
sb->s_blocks_per_group = info.blocks_per_group;
sb->s_obso_frags_per_group = info.blocks_per_group;
sb->s_inodes_per_group = info.inodes_per_group;
sb->s_mtime = 0;
sb->s_wtime = 0;
sb->s_mnt_count = 0;
sb->s_max_mnt_count = 0xFFFF;
sb->s_magic = EXT4_SUPER_MAGIC;
sb->s_state = EXT4_VALID_FS;
sb->s_errors = EXT4_ERRORS_RO;
sb->s_minor_rev_level = 0;
sb->s_lastcheck = 0;
sb->s_checkinterval = 0;
sb->s_creator_os = EXT4_OS_LINUX;
sb->s_rev_level = EXT4_DYNAMIC_REV;
sb->s_def_resuid = EXT4_DEF_RESUID;
sb->s_def_resgid = EXT4_DEF_RESGID;
sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
sb->s_inode_size = info.inode_size;
sb->s_block_group_nr = 0;
sb->s_feature_compat = info.feat_compat;
sb->s_feature_incompat = info.feat_incompat;
sb->s_feature_ro_compat = info.feat_ro_compat;
generate_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
sb->s_algorithm_usage_bitmap = 0;
sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks;
sb->s_prealloc_blocks = 0;
sb->s_prealloc_dir_blocks = 0;
//memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
sb->s_journal_inum = EXT4_JOURNAL_INO;
sb->s_journal_dev = 0;
sb->s_last_orphan = 0;
sb->s_hash_seed[0] = 0; /* FIXME */
sb->s_def_hash_version = DX_HASH_TEA;
sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
sb->s_desc_size = sizeof(struct ext2_group_desc);
sb->s_default_mount_opts = 0; /* FIXME */
sb->s_first_meta_bg = 0;
sb->s_mkfs_time = 0;
//sb->s_jnl_blocks[17]; /* FIXME */
sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
sb->s_r_blocks_count_hi = 0;
sb->s_free_blocks_count_hi = 0;
sb->s_min_extra_isize = sizeof(struct ext4_inode) -
EXT4_GOOD_OLD_INODE_SIZE;
sb->s_want_extra_isize = sizeof(struct ext4_inode) -
EXT4_GOOD_OLD_INODE_SIZE;
sb->s_flags = 2;
sb->s_raid_stride = 0;
sb->s_mmp_interval = 0;
sb->s_mmp_block = 0;
sb->s_raid_stripe_width = 0;
sb->s_log_groups_per_flex = 0;
sb->s_kbytes_written = 0;
for (i = 0; i < aux_info.groups; i++) {
u64 group_start_block = aux_info.first_data_block + i *
info.blocks_per_group;
u32 header_size = 0;
if (ext4_bg_has_super_block(i)) {
if (i != 0) {
aux_info.backup_sb[i] = calloc(info.block_size, 1);
memcpy(aux_info.backup_sb[i], sb, info.block_size);
/* Update the block group nr of this backup superblock */
aux_info.backup_sb[i]->s_block_group_nr = i;
sparse_file_add_data(ext4_sparse_file, aux_info.backup_sb[i],
info.block_size, group_start_block);
}
sparse_file_add_data(ext4_sparse_file, aux_info.bg_desc,
aux_info.bg_desc_blocks * info.block_size,
group_start_block + 1);
header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
}
aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
aux_info.bg_desc[i].bg_used_dirs_count = 0;
}
}
void ext4_queue_sb(void)
{
/* The write_data* functions expect only block aligned calls.
* This is not an issue, except when we write out the super
* block on a system with a block size > 1K. So, we need to
* deal with that here.
*/
if (info.block_size > 1024) {
u8 *buf = calloc(info.block_size, 1);
memcpy(buf + 1024, (u8*)aux_info.sb, 1024);
sparse_file_add_data(ext4_sparse_file, buf, info.block_size, 0);
} else {
sparse_file_add_data(ext4_sparse_file, aux_info.sb, 1024, 1);
}
}
void ext4_parse_sb_info(struct ext4_super_block *sb)
{
if (sb->s_magic != EXT4_SUPER_MAGIC)
error("superblock magic incorrect");
if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
error("filesystem state not valid");
ext4_parse_sb(sb, &info);
ext4_create_fs_aux_info();
memcpy(aux_info.sb, sb, sizeof(*sb));
if (aux_info.first_data_block != sb->s_first_data_block)
critical_error("first data block does not match");
}
void ext4_create_resize_inode()
{
struct block_allocation *reserve_inode_alloc = create_allocation();
u32 reserve_inode_len = 0;
unsigned int i;
struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
if (inode == NULL) {
error("failed to get resize inode");
return;
}
for (i = 0; i < aux_info.groups; i++) {
if (ext4_bg_has_super_block(i)) {
u64 group_start_block = aux_info.first_data_block + i *
info.blocks_per_group;
u32 reserved_block_start = group_start_block + 1 +
aux_info.bg_desc_blocks;
u32 reserved_block_len = info.bg_desc_reserve_blocks;
append_region(reserve_inode_alloc, reserved_block_start,
reserved_block_len, i);
reserve_inode_len += reserved_block_len;
}
}
inode_attach_resize(inode, reserve_inode_alloc);
inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
inode->i_links_count = 1;
free_alloc(reserve_inode_alloc);
}
/* Allocate the blocks to hold a journal inode and connect them to the
reserved journal inode */
void ext4_create_journal_inode()
{
struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
if (inode == NULL) {
error("failed to get journal inode");
return;
}
u8 *journal_data = inode_allocate_data_extents(inode,
info.journal_blocks * info.block_size,
info.journal_blocks * info.block_size);
if (!journal_data) {
error("failed to allocate extents for journal data");
return;
}
inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
inode->i_links_count = 1;
journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
jsb->s_blocksize = htonl(info.block_size);
jsb->s_maxlen = htonl(info.journal_blocks);
jsb->s_nr_users = htonl(1);
jsb->s_first = htonl(1);
jsb->s_sequence = htonl(1);
memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
}
/* Update the number of free blocks and inodes in the filesystem and in each
block group */
void ext4_update_free()
{
u32 i;
for (i = 0; i < aux_info.groups; i++) {
u32 bg_free_blocks = get_free_blocks(i);
u32 bg_free_inodes = get_free_inodes(i);
u16 crc;
aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
aux_info.sb->s_free_inodes_count += bg_free_inodes;
aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
aux_info.bg_desc[i].bg_flags = get_bg_flags(i);
crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid));
crc = ext4_crc16(crc, &i, sizeof(i));
crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum));
aux_info.bg_desc[i].bg_checksum = crc;
}
}
u64 get_block_device_size(int fd)
{
u64 size = 0;
int ret;
#if defined(__linux__)
ret = ioctl(fd, BLKGETSIZE64, &size);
#elif defined(__APPLE__) && defined(__MACH__)
ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
#else
close(fd);
return 0;
#endif
if (ret)
return 0;
return size;
}
int is_block_device_fd(int fd)
{
struct stat st;
int ret = fstat(fd, &st);
if (ret < 0)
return 0;
return S_ISBLK(st.st_mode);
}
u64 get_file_size(int fd)
{
struct stat buf;
int ret;
u64 reserve_len = 0;
s64 computed_size;
ret = fstat(fd, &buf);
if (ret)
return 0;
if (info.len < 0)
reserve_len = -info.len;
if (S_ISREG(buf.st_mode))
computed_size = buf.st_size - reserve_len;
else if (S_ISBLK(buf.st_mode))
computed_size = get_block_device_size(fd) - reserve_len;
else
computed_size = 0;
if (computed_size < 0) {
warn("Computed filesystem size less than 0");
computed_size = 0;
}
return computed_size;
}
u64 parse_num(const char *arg)
{
char *endptr;
u64 num = strtoull(arg, &endptr, 10);
if (*endptr == 'k' || *endptr == 'K')
num *= 1024LL;
else if (*endptr == 'm' || *endptr == 'M')
num *= 1024LL * 1024LL;
else if (*endptr == 'g' || *endptr == 'G')
num *= 1024LL * 1024LL * 1024LL;
return num;
}
int read_ext(int fd, int verbose)
{
off64_t ret;
struct ext4_super_block sb;
read_sb(fd, &sb);
ext4_parse_sb_info(&sb);
ret = lseek64(fd, info.len, SEEK_SET);
if (ret < 0)
critical_error_errno("failed to seek to end of input image");
ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET);
if (ret < 0)
critical_error_errno("failed to seek to block group descriptors");
ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
if (ret < 0)
critical_error_errno("failed to read block group descriptors");
if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
critical_error("failed to read all of block group descriptors");
if (verbose) {
printf("Found filesystem with parameters:\n");
printf(" Size: %"PRIu64"\n", info.len);
printf(" Block size: %d\n", info.block_size);
printf(" Blocks per group: %d\n", info.blocks_per_group);
printf(" Inodes per group: %d\n", info.inodes_per_group);
printf(" Inode size: %d\n", info.inode_size);
printf(" Label: %s\n", info.label);
printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks);
printf(" Block groups: %d\n", aux_info.groups);
printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
printf(" Used %d/%d inodes and %d/%d blocks\n",
aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
aux_info.sb->s_inodes_count,
aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
aux_info.sb->s_blocks_count_lo);
}
return 0;
}