717 lines
26 KiB
C
717 lines
26 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* mkfs_ext2: utility to create EXT2 filesystem
|
|
* inspired by genext2fs
|
|
*
|
|
* Busybox'ed (2009) by Vladimir Dronnikov <dronnikov@gmail.com>
|
|
*
|
|
* Licensed under GPLv2, see file LICENSE in this source tree.
|
|
*/
|
|
//config:config MKE2FS
|
|
//config: bool "mke2fs"
|
|
//config: default y
|
|
//config: select PLATFORM_LINUX
|
|
//config: help
|
|
//config: Utility to create EXT2 filesystems.
|
|
//config:
|
|
//config:config MKFS_EXT2
|
|
//config: bool "mkfs.ext2"
|
|
//config: default y
|
|
//config: select PLATFORM_LINUX
|
|
//config: help
|
|
//config: Alias to "mke2fs".
|
|
|
|
// APPLET_ODDNAME:name main location suid_type help
|
|
//applet:IF_MKE2FS( APPLET_ODDNAME(mke2fs, mkfs_ext2, BB_DIR_SBIN, BB_SUID_DROP, mkfs_ext2))
|
|
//applet:IF_MKFS_EXT2(APPLET_ODDNAME(mkfs.ext2, mkfs_ext2, BB_DIR_SBIN, BB_SUID_DROP, mkfs_ext2))
|
|
////////:IF_MKFS_EXT3(APPLET_ODDNAME(mkfs.ext3, mkfs_ext2, BB_DIR_SBIN, BB_SUID_DROP, mkfs_ext2))
|
|
|
|
//kbuild:lib-$(CONFIG_MKE2FS) += mkfs_ext2.o
|
|
//kbuild:lib-$(CONFIG_MKFS_EXT2) += mkfs_ext2.o
|
|
|
|
//usage:#define mkfs_ext2_trivial_usage
|
|
//usage: "[-Fn] "
|
|
/* //usage: "[-c|-l filename] " */
|
|
//usage: "[-b BLK_SIZE] "
|
|
/* //usage: "[-f fragment-size] [-g blocks-per-group] " */
|
|
//usage: "[-i INODE_RATIO] [-I INODE_SIZE] "
|
|
/* //usage: "[-j] [-J journal-options] [-N number-of-inodes] " */
|
|
//usage: "[-m RESERVED_PERCENT] "
|
|
/* //usage: "[-o creator-os] [-O feature[,...]] [-q] " */
|
|
/* //usage: "[r fs-revision-level] [-E extended-options] [-v] [-F] " */
|
|
//usage: "[-L LABEL] "
|
|
/* //usage: "[-M last-mounted-directory] [-S] [-T filesystem-type] " */
|
|
//usage: "BLOCKDEV [KBYTES]"
|
|
//usage:#define mkfs_ext2_full_usage "\n\n"
|
|
//usage: " -b BLK_SIZE Block size, bytes"
|
|
/* //usage: "\n -c Check device for bad blocks" */
|
|
/* //usage: "\n -E opts Set extended options" */
|
|
/* //usage: "\n -f size Fragment size in bytes" */
|
|
//usage: "\n -F Force"
|
|
/* //usage: "\n -g N Number of blocks in a block group" */
|
|
//usage: "\n -i RATIO Max number of files is filesystem_size / RATIO"
|
|
//usage: "\n -I BYTES Inode size (min 128)"
|
|
/* //usage: "\n -j Create a journal (ext3)" */
|
|
/* //usage: "\n -J opts Set journal options (size/device)" */
|
|
/* //usage: "\n -l file Read bad blocks list from file" */
|
|
//usage: "\n -L LBL Volume label"
|
|
//usage: "\n -m PERCENT Percent of blocks to reserve for admin"
|
|
/* //usage: "\n -M dir Set last mounted directory" */
|
|
//usage: "\n -n Dry run"
|
|
/* //usage: "\n -N N Number of inodes to create" */
|
|
/* //usage: "\n -o os Set the 'creator os' field" */
|
|
/* //usage: "\n -O features Dir_index/filetype/has_journal/journal_dev/sparse_super" */
|
|
/* //usage: "\n -q Quiet" */
|
|
/* //usage: "\n -r rev Set filesystem revision" */
|
|
/* //usage: "\n -S Write superblock and group descriptors only" */
|
|
/* //usage: "\n -T fs-type Set usage type (news/largefile/largefile4)" */
|
|
/* //usage: "\n -v Verbose" */
|
|
|
|
#include "libbb.h"
|
|
#include <linux/fs.h>
|
|
#include "bb_e2fs_defs.h"
|
|
|
|
#define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
|
|
#define ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX 1
|
|
|
|
#define EXT2_HASH_HALF_MD4 1
|
|
#define EXT2_FLAGS_SIGNED_HASH 0x0001
|
|
#define EXT2_FLAGS_UNSIGNED_HASH 0x0002
|
|
|
|
// storage helpers
|
|
char BUG_wrong_field_size(void);
|
|
#define STORE_LE(field, value) \
|
|
do { \
|
|
if (sizeof(field) == 4) \
|
|
field = SWAP_LE32(value); \
|
|
else if (sizeof(field) == 2) \
|
|
field = SWAP_LE16(value); \
|
|
else if (sizeof(field) == 1) \
|
|
field = (value); \
|
|
else \
|
|
BUG_wrong_field_size(); \
|
|
} while (0)
|
|
|
|
#define FETCH_LE32(field) \
|
|
(sizeof(field) == 4 ? SWAP_LE32(field) : BUG_wrong_field_size())
|
|
|
|
// All fields are little-endian
|
|
struct ext2_dir {
|
|
uint32_t inode1;
|
|
uint16_t rec_len1;
|
|
uint8_t name_len1;
|
|
uint8_t file_type1;
|
|
char name1[4];
|
|
uint32_t inode2;
|
|
uint16_t rec_len2;
|
|
uint8_t name_len2;
|
|
uint8_t file_type2;
|
|
char name2[4];
|
|
uint32_t inode3;
|
|
uint16_t rec_len3;
|
|
uint8_t name_len3;
|
|
uint8_t file_type3;
|
|
char name3[12];
|
|
};
|
|
|
|
static unsigned int_log2(unsigned arg)
|
|
{
|
|
unsigned r = 0;
|
|
while ((arg >>= 1) != 0)
|
|
r++;
|
|
return r;
|
|
}
|
|
|
|
// taken from mkfs_minix.c. libbb candidate?
|
|
// "uint32_t size", since we never use it for anything >32 bits
|
|
static uint32_t div_roundup(uint32_t size, uint32_t n)
|
|
{
|
|
// Overflow-resistant
|
|
uint32_t res = size / n;
|
|
if (res * n != size)
|
|
res++;
|
|
return res;
|
|
}
|
|
|
|
static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32_t end)
|
|
{
|
|
uint32_t i;
|
|
|
|
//bb_error_msg("ALLOC: [%u][%u][%u]: [%u-%u]:=[%x],[%x]", blocksize, start, end, start/8, blocksize - end/8 - 1, (1 << (start & 7)) - 1, (uint8_t)(0xFF00 >> (end & 7)));
|
|
memset(bitmap, 0, blocksize);
|
|
i = start / 8;
|
|
memset(bitmap, 0xFF, i);
|
|
bitmap[i] = (1 << (start & 7)) - 1; //0..7 => 00000000..01111111
|
|
i = end / 8;
|
|
bitmap[blocksize - i - 1] |= 0x7F00 >> (end & 7); //0..7 => 00000000..11111110
|
|
memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here!
|
|
}
|
|
|
|
static uint32_t has_super(uint32_t x)
|
|
{
|
|
// 0, 1 and powers of 3, 5, 7 up to 2^32 limit
|
|
static const uint32_t supers[] = {
|
|
0, 1, 3, 5, 7, 9, 25, 27, 49, 81, 125, 243, 343, 625, 729,
|
|
2187, 2401, 3125, 6561, 15625, 16807, 19683, 59049, 78125,
|
|
117649, 177147, 390625, 531441, 823543, 1594323, 1953125,
|
|
4782969, 5764801, 9765625, 14348907, 40353607, 43046721,
|
|
48828125, 129140163, 244140625, 282475249, 387420489,
|
|
1162261467, 1220703125, 1977326743, 3486784401/* >2^31 */,
|
|
};
|
|
const uint32_t *sp = supers + ARRAY_SIZE(supers);
|
|
while (1) {
|
|
sp--;
|
|
if (x == *sp)
|
|
return 1;
|
|
if (x > *sp)
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
#define fd 3 /* predefined output descriptor */
|
|
|
|
static void PUT(uint64_t off, void *buf, uint32_t size)
|
|
{
|
|
//bb_error_msg("PUT[%llu]:[%u]", off, size);
|
|
xlseek(fd, off, SEEK_SET);
|
|
xwrite(fd, buf, size);
|
|
}
|
|
|
|
// 128 and 256-byte inodes:
|
|
// 128-byte inode is described by struct ext2_inode.
|
|
// 256-byte one just has these fields appended:
|
|
// __u16 i_extra_isize;
|
|
// __u16 i_pad1;
|
|
// __u32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */
|
|
// __u32 i_mtime_extra; /* extra Modification time (nsec << 2 | epoch) */
|
|
// __u32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */
|
|
// __u32 i_crtime; /* File creation time */
|
|
// __u32 i_crtime_extra; /* extra File creation time (nsec << 2 | epoch)*/
|
|
// __u32 i_version_hi; /* high 32 bits for 64-bit version */
|
|
// the rest is padding.
|
|
//
|
|
// linux/ext2_fs.h has "#define i_size_high i_dir_acl" which suggests that even
|
|
// 128-byte inode is capable of describing large files (i_dir_acl is meaningful
|
|
// only for directories, which never need i_size_high).
|
|
//
|
|
// Standard mke2fs creates a filesystem with 256-byte inodes if it is
|
|
// bigger than 0.5GB.
|
|
|
|
// Standard mke2fs 1.41.9:
|
|
// Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size]
|
|
// [-i bytes-per-inode] [-I inode-size] [-J journal-options]
|
|
// [-G meta group size] [-N number-of-inodes]
|
|
// [-m reserved-blocks-percentage] [-o creator-os]
|
|
// [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
|
|
// [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
|
|
// [-T fs-type] [-U UUID] [-jnqvFSV] device [blocks-count]
|
|
//
|
|
// Options not commented below are taken but silently ignored:
|
|
enum {
|
|
OPT_c = 1 << 0,
|
|
OPT_l = 1 << 1,
|
|
OPT_b = 1 << 2, // block size, in bytes
|
|
OPT_f = 1 << 3,
|
|
OPT_i = 1 << 4, // bytes per inode
|
|
OPT_I = 1 << 5, // custom inode size, in bytes
|
|
OPT_J = 1 << 6,
|
|
OPT_G = 1 << 7,
|
|
OPT_N = 1 << 8,
|
|
OPT_m = 1 << 9, // percentage of blocks reserved for superuser
|
|
OPT_o = 1 << 10,
|
|
OPT_g = 1 << 11,
|
|
OPT_L = 1 << 12, // label
|
|
OPT_M = 1 << 13,
|
|
OPT_O = 1 << 14,
|
|
OPT_r = 1 << 15,
|
|
OPT_E = 1 << 16,
|
|
OPT_T = 1 << 17,
|
|
OPT_U = 1 << 18,
|
|
OPT_j = 1 << 19,
|
|
OPT_n = 1 << 20, // dry run: do not write anything
|
|
OPT_q = 1 << 21,
|
|
OPT_v = 1 << 22,
|
|
OPT_F = 1 << 23,
|
|
OPT_S = 1 << 24,
|
|
//OPT_V = 1 << 25, // -V version. bbox applets don't support that
|
|
};
|
|
|
|
int mkfs_ext2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
|
int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
|
|
{
|
|
unsigned i, pos, n;
|
|
unsigned bs, bpi;
|
|
unsigned blocksize, blocksize_log2;
|
|
unsigned inodesize, user_inodesize;
|
|
unsigned reserved_percent = 5;
|
|
unsigned long long kilobytes;
|
|
uint32_t nblocks, nblocks_full;
|
|
uint32_t nreserved;
|
|
uint32_t ngroups;
|
|
uint32_t bytes_per_inode;
|
|
uint32_t first_block;
|
|
uint32_t inodes_per_group;
|
|
uint32_t group_desc_blocks;
|
|
uint32_t inode_table_blocks;
|
|
uint32_t lost_and_found_blocks;
|
|
time_t timestamp;
|
|
const char *label = "";
|
|
struct stat st;
|
|
struct ext2_super_block *sb; // superblock
|
|
struct ext2_group_desc *gd; // group descriptors
|
|
struct ext2_inode *inode;
|
|
struct ext2_dir *dir;
|
|
uint8_t *buf;
|
|
|
|
// using global "option_mask32" instead of local "opts":
|
|
// we are register starved here
|
|
/*opts =*/ getopt32(argv, "cl:b:+f:i:+I:+J:G:N:m:+o:g:L:M:O:r:E:T:U:jnqvFS",
|
|
/*lbfi:*/ NULL, &bs, NULL, &bpi,
|
|
/*IJGN:*/ &user_inodesize, NULL, NULL, NULL,
|
|
/*mogL:*/ &reserved_percent, NULL, NULL, &label,
|
|
/*MOrE:*/ NULL, NULL, NULL, NULL,
|
|
/*TU:*/ NULL, NULL);
|
|
argv += optind; // argv[0] -- device
|
|
|
|
// open the device, check the device is a block device
|
|
xmove_fd(xopen(argv[0], O_WRONLY), fd);
|
|
xfstat(fd, &st, argv[0]);
|
|
if (!S_ISBLK(st.st_mode) && !(option_mask32 & OPT_F))
|
|
bb_error_msg_and_die("%s: not a block device", argv[0]);
|
|
|
|
// check if it is mounted
|
|
// N.B. what if we format a file? find_mount_point will return false negative since
|
|
// it is loop block device which is mounted!
|
|
if (find_mount_point(argv[0], 0))
|
|
bb_error_msg_and_die("can't format mounted filesystem");
|
|
|
|
// get size in kbytes
|
|
kilobytes = get_volume_size_in_bytes(fd, argv[1], 1024, /*extend:*/ !(option_mask32 & OPT_n)) / 1024;
|
|
|
|
bytes_per_inode = 16384;
|
|
if (kilobytes < 512*1024)
|
|
bytes_per_inode = 4096;
|
|
if (kilobytes < 3*1024)
|
|
bytes_per_inode = 8192;
|
|
if (option_mask32 & OPT_i)
|
|
bytes_per_inode = bpi;
|
|
|
|
// Determine block size and inode size
|
|
// block size is a multiple of 1024
|
|
// inode size is a multiple of 128
|
|
blocksize = 1024;
|
|
inodesize = sizeof(struct ext2_inode); // 128
|
|
if (kilobytes >= 512*1024) { // mke2fs 1.41.9 compat
|
|
blocksize = 4096;
|
|
inodesize = 256;
|
|
}
|
|
if (EXT2_MAX_BLOCK_SIZE > 4096) {
|
|
// kilobytes >> 22 == size in 4gigabyte chunks.
|
|
// if size >= 16k gigs, blocksize must be increased.
|
|
// Try "mke2fs -F image $((16 * 1024*1024*1024))"
|
|
while ((kilobytes >> 22) >= blocksize)
|
|
blocksize *= 2;
|
|
}
|
|
if (option_mask32 & OPT_b)
|
|
blocksize = bs;
|
|
if (blocksize < EXT2_MIN_BLOCK_SIZE
|
|
|| blocksize > EXT2_MAX_BLOCK_SIZE
|
|
|| (blocksize & (blocksize - 1)) // not power of 2
|
|
) {
|
|
bb_error_msg_and_die("blocksize %u is bad", blocksize);
|
|
}
|
|
// Do we have custom inode size?
|
|
if (option_mask32 & OPT_I) {
|
|
if (user_inodesize < sizeof(*inode)
|
|
|| user_inodesize > blocksize
|
|
|| (user_inodesize & (user_inodesize - 1)) // not power of 2
|
|
) {
|
|
bb_error_msg("-%c is bad", 'I');
|
|
} else {
|
|
inodesize = user_inodesize;
|
|
}
|
|
}
|
|
|
|
if ((int32_t)bytes_per_inode < blocksize)
|
|
bb_error_msg_and_die("-%c is bad", 'i');
|
|
// number of bits in one block, i.e. 8*blocksize
|
|
#define blocks_per_group (8 * blocksize)
|
|
first_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
|
|
blocksize_log2 = int_log2(blocksize);
|
|
|
|
// Determine number of blocks
|
|
kilobytes >>= (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
|
|
nblocks = kilobytes;
|
|
if (nblocks != kilobytes)
|
|
bb_error_msg_and_die("block count doesn't fit in 32 bits");
|
|
#define kilobytes kilobytes_unused_after_this
|
|
// Experimentally, standard mke2fs won't work on images smaller than 60k
|
|
if (nblocks < 60)
|
|
bb_error_msg_and_die("need >= 60 blocks");
|
|
|
|
// How many reserved blocks?
|
|
if (reserved_percent > 50)
|
|
bb_error_msg_and_die("-%c is bad", 'm');
|
|
nreserved = (uint64_t)nblocks * reserved_percent / 100;
|
|
|
|
// N.B. killing e2fsprogs feature! Unused blocks don't account in calculations
|
|
nblocks_full = nblocks;
|
|
|
|
// If last block group is too small, nblocks may be decreased in order
|
|
// to discard it, and control returns here to recalculate some
|
|
// parameters.
|
|
// Note: blocksize and bytes_per_inode are never recalculated.
|
|
retry:
|
|
// N.B. a block group can have no more than blocks_per_group blocks
|
|
ngroups = div_roundup(nblocks - first_block, blocks_per_group);
|
|
|
|
group_desc_blocks = div_roundup(ngroups, blocksize / sizeof(*gd));
|
|
// TODO: reserved blocks must be marked as such in the bitmaps,
|
|
// or resulting filesystem is corrupt
|
|
if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) {
|
|
/*
|
|
* From e2fsprogs: Calculate the number of GDT blocks to reserve for online
|
|
* filesystem growth.
|
|
* The absolute maximum number of GDT blocks we can reserve is determined by
|
|
* the number of block pointers that can fit into a single block.
|
|
* We set it at 1024x the current filesystem size, or
|
|
* the upper block count limit (2^32), whichever is lower.
|
|
*/
|
|
uint32_t reserved_group_desc_blocks = 0xFFFFFFFF; // maximum block number
|
|
if (nblocks < reserved_group_desc_blocks / 1024)
|
|
reserved_group_desc_blocks = nblocks * 1024;
|
|
reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks - first_block, blocks_per_group);
|
|
reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks, blocksize / sizeof(*gd)) - group_desc_blocks;
|
|
if (reserved_group_desc_blocks > blocksize / sizeof(uint32_t))
|
|
reserved_group_desc_blocks = blocksize / sizeof(uint32_t);
|
|
//TODO: STORE_LE(sb->s_reserved_gdt_blocks, reserved_group_desc_blocks);
|
|
group_desc_blocks += reserved_group_desc_blocks;
|
|
}
|
|
|
|
{
|
|
// N.B. e2fsprogs does as follows!
|
|
uint32_t overhead, remainder;
|
|
// ninodes is the max number of inodes in this filesystem
|
|
uint32_t ninodes = ((uint64_t) nblocks_full * blocksize) / bytes_per_inode;
|
|
if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
|
|
ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
|
|
inodes_per_group = div_roundup(ninodes, ngroups);
|
|
// minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
|
|
if (inodes_per_group < 16)
|
|
inodes_per_group = 16;
|
|
// a block group can't have more inodes than blocks
|
|
if (inodes_per_group > blocks_per_group)
|
|
inodes_per_group = blocks_per_group;
|
|
// adjust inodes per group so they completely fill the inode table blocks in the descriptor
|
|
inodes_per_group = (div_roundup(inodes_per_group * inodesize, blocksize) * blocksize) / inodesize;
|
|
// make sure the number of inodes per group is a multiple of 8
|
|
inodes_per_group &= ~7;
|
|
inode_table_blocks = div_roundup(inodes_per_group * inodesize, blocksize);
|
|
|
|
// to be useful, lost+found should occupy at least 2 blocks (but not exceeding 16*1024 bytes),
|
|
// and at most EXT2_NDIR_BLOCKS. So reserve these blocks right now
|
|
/* Or e2fsprogs comment verbatim (what does it mean?):
|
|
* Ensure that lost+found is at least 2 blocks, so we always
|
|
* test large empty blocks for big-block filesystems. */
|
|
lost_and_found_blocks = MIN(EXT2_NDIR_BLOCKS, 16 >> (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE));
|
|
|
|
// the last group needs more attention: isn't it too small for possible overhead?
|
|
overhead = (has_super(ngroups - 1) ? (1/*sb*/ + group_desc_blocks) : 0) + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
|
|
remainder = (nblocks - first_block) % blocks_per_group;
|
|
////can't happen, nblocks >= 60 guarantees this
|
|
////if ((1 == ngroups)
|
|
//// && remainder
|
|
//// && (remainder < overhead + 1/* "/" */ + lost_and_found_blocks)
|
|
////) {
|
|
//// bb_error_msg_and_die("way small device");
|
|
////}
|
|
|
|
// Standard mke2fs uses 50. Looks like a bug in our calculation
|
|
// of "remainder" or "overhead" - we don't match standard mke2fs
|
|
// when we transition from one group to two groups
|
|
// (a bit after 8M image size), but it works for two->three groups
|
|
// transition (at 16M).
|
|
if (remainder && (remainder < overhead + 50)) {
|
|
//bb_error_msg("CHOP[%u]", remainder);
|
|
nblocks -= remainder;
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
if (nblocks_full - nblocks)
|
|
printf("warning: %u blocks unused\n\n", nblocks_full - nblocks);
|
|
printf(
|
|
"Filesystem label=%s\n"
|
|
"OS type: Linux\n"
|
|
"Block size=%u (log=%u)\n"
|
|
"Fragment size=%u (log=%u)\n"
|
|
"%u inodes, %u blocks\n"
|
|
"%u blocks (%u%%) reserved for the super user\n"
|
|
"First data block=%u\n"
|
|
"Maximum filesystem blocks=%u\n"
|
|
"%u block groups\n"
|
|
"%u blocks per group, %u fragments per group\n"
|
|
"%u inodes per group"
|
|
, label
|
|
, blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
|
|
, blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
|
|
, inodes_per_group * ngroups, nblocks
|
|
, nreserved, reserved_percent
|
|
, first_block
|
|
, group_desc_blocks * (blocksize / (unsigned)sizeof(*gd)) * blocks_per_group
|
|
, ngroups
|
|
, blocks_per_group, blocks_per_group
|
|
, inodes_per_group
|
|
);
|
|
{
|
|
const char *fmt = "\nSuperblock backups stored on blocks:\n"
|
|
"\t%u";
|
|
pos = first_block;
|
|
for (i = 1; i < ngroups; i++) {
|
|
pos += blocks_per_group;
|
|
if (has_super(i)) {
|
|
printf(fmt, (unsigned)pos);
|
|
fmt = ", %u";
|
|
}
|
|
}
|
|
}
|
|
bb_putchar('\n');
|
|
|
|
if (option_mask32 & OPT_n) {
|
|
if (ENABLE_FEATURE_CLEAN_UP)
|
|
close(fd);
|
|
return EXIT_SUCCESS;
|
|
}
|
|
|
|
// TODO: 3/5 refuse if mounted
|
|
// TODO: 4/5 compat options
|
|
// TODO: 1/5 sanity checks
|
|
// TODO: 0/5 more verbose error messages
|
|
// TODO: 4/5 bigendianness: recheck, wait for ARM reporters
|
|
// TODO: 2/5 reserved GDT: how to mark but not allocate?
|
|
// TODO: 3/5 dir_index?
|
|
|
|
// fill the superblock
|
|
sb = xzalloc(1024);
|
|
STORE_LE(sb->s_rev_level, EXT2_DYNAMIC_REV); // revision 1 filesystem
|
|
STORE_LE(sb->s_magic, EXT2_SUPER_MAGIC);
|
|
STORE_LE(sb->s_inode_size, inodesize);
|
|
// set "Required extra isize" and "Desired extra isize" fields to 28
|
|
if (inodesize != sizeof(*inode)) {
|
|
STORE_LE(sb->s_min_extra_isize, 0x001c);
|
|
STORE_LE(sb->s_want_extra_isize, 0x001c);
|
|
}
|
|
STORE_LE(sb->s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
|
|
STORE_LE(sb->s_log_block_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
|
|
STORE_LE(sb->s_log_frag_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
|
|
// first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then
|
|
// the first block is 1, otherwise 0
|
|
STORE_LE(sb->s_first_data_block, first_block);
|
|
// block and inode bitmaps occupy no more than one block, so maximum number of blocks is
|
|
STORE_LE(sb->s_blocks_per_group, blocks_per_group);
|
|
STORE_LE(sb->s_frags_per_group, blocks_per_group);
|
|
// blocks
|
|
STORE_LE(sb->s_blocks_count, nblocks);
|
|
// reserve blocks for superuser
|
|
STORE_LE(sb->s_r_blocks_count, nreserved);
|
|
// ninodes
|
|
STORE_LE(sb->s_inodes_per_group, inodes_per_group);
|
|
STORE_LE(sb->s_inodes_count, inodes_per_group * ngroups);
|
|
STORE_LE(sb->s_free_inodes_count, inodes_per_group * ngroups - EXT2_GOOD_OLD_FIRST_INO);
|
|
// timestamps
|
|
timestamp = time(NULL);
|
|
STORE_LE(sb->s_mkfs_time, timestamp);
|
|
STORE_LE(sb->s_wtime, timestamp);
|
|
STORE_LE(sb->s_lastcheck, timestamp);
|
|
// misc. Values are chosen to match mke2fs 1.41.9
|
|
STORE_LE(sb->s_state, 1); // TODO: what's 1?
|
|
STORE_LE(sb->s_creator_os, EXT2_OS_LINUX);
|
|
STORE_LE(sb->s_checkinterval, 24*60*60 * 180); // 180 days
|
|
STORE_LE(sb->s_errors, EXT2_ERRORS_DEFAULT);
|
|
// mke2fs 1.41.9 also sets EXT3_FEATURE_COMPAT_RESIZE_INODE
|
|
// and if >= 0.5GB, EXT3_FEATURE_RO_COMPAT_LARGE_FILE.
|
|
// we use values which match "mke2fs -O ^resize_inode":
|
|
// in this case 1.41.9 never sets EXT3_FEATURE_RO_COMPAT_LARGE_FILE.
|
|
STORE_LE(sb->s_feature_compat, EXT2_FEATURE_COMPAT_SUPP
|
|
| (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
|
|
| (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
|
|
);
|
|
STORE_LE(sb->s_feature_incompat, EXT2_FEATURE_INCOMPAT_FILETYPE);
|
|
STORE_LE(sb->s_feature_ro_compat, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
|
|
STORE_LE(sb->s_flags, EXT2_FLAGS_UNSIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX);
|
|
generate_uuid(sb->s_uuid);
|
|
if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
|
|
STORE_LE(sb->s_def_hash_version, EXT2_HASH_HALF_MD4);
|
|
generate_uuid((uint8_t *)sb->s_hash_seed);
|
|
}
|
|
/*
|
|
* From e2fsprogs: add "jitter" to the superblock's check interval so that we
|
|
* don't check all the filesystems at the same time. We use a
|
|
* kludgy hack of using the UUID to derive a random jitter value.
|
|
*/
|
|
STORE_LE(sb->s_max_mnt_count,
|
|
EXT2_DFL_MAX_MNT_COUNT
|
|
+ (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));
|
|
|
|
// write the label
|
|
safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
|
|
|
|
// calculate filesystem skeleton structures
|
|
gd = xzalloc(group_desc_blocks * blocksize);
|
|
buf = xmalloc(blocksize);
|
|
sb->s_free_blocks_count = 0;
|
|
for (i = 0, pos = first_block, n = nblocks - first_block;
|
|
i < ngroups;
|
|
i++, pos += blocks_per_group, n -= blocks_per_group
|
|
) {
|
|
uint32_t overhead = pos + (has_super(i) ? (1/*sb*/ + group_desc_blocks) : 0);
|
|
uint32_t free_blocks;
|
|
// fill group descriptors
|
|
STORE_LE(gd[i].bg_block_bitmap, overhead + 0);
|
|
STORE_LE(gd[i].bg_inode_bitmap, overhead + 1);
|
|
STORE_LE(gd[i].bg_inode_table, overhead + 2);
|
|
overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
|
|
gd[i].bg_free_inodes_count = inodes_per_group;
|
|
//STORE_LE(gd[i].bg_used_dirs_count, 0);
|
|
// N.B. both "/" and "/lost+found" are within the first block group
|
|
// "/" occupies 1 block, "/lost+found" occupies lost_and_found_blocks...
|
|
if (0 == i) {
|
|
// ... thus increased overhead for the first block group ...
|
|
overhead += 1 + lost_and_found_blocks;
|
|
// ... and 2 used directories
|
|
STORE_LE(gd[i].bg_used_dirs_count, 2);
|
|
// well known reserved inodes belong to the first block too
|
|
gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO;
|
|
}
|
|
|
|
// cache free block count of the group
|
|
free_blocks = (n < blocks_per_group ? n : blocks_per_group) - overhead;
|
|
|
|
// mark preallocated blocks as allocated
|
|
//bb_error_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (free_blocks + overhead));
|
|
allocate(buf, blocksize,
|
|
// reserve "overhead" blocks
|
|
overhead,
|
|
// mark unused trailing blocks
|
|
blocks_per_group - (free_blocks + overhead)
|
|
);
|
|
// dump block bitmap
|
|
PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
|
|
STORE_LE(gd[i].bg_free_blocks_count, free_blocks);
|
|
|
|
// mark preallocated inodes as allocated
|
|
allocate(buf, blocksize,
|
|
// mark reserved inodes
|
|
inodes_per_group - gd[i].bg_free_inodes_count,
|
|
// mark unused trailing inodes
|
|
blocks_per_group - inodes_per_group
|
|
);
|
|
// dump inode bitmap
|
|
//PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
|
|
//but it's right after block bitmap, so we can just:
|
|
xwrite(fd, buf, blocksize);
|
|
STORE_LE(gd[i].bg_free_inodes_count, gd[i].bg_free_inodes_count);
|
|
|
|
// count overall free blocks
|
|
sb->s_free_blocks_count += free_blocks;
|
|
}
|
|
STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
|
|
|
|
// dump filesystem skeleton structures
|
|
// printf("Writing superblocks and filesystem accounting information: ");
|
|
for (i = 0, pos = first_block; i < ngroups; i++, pos += blocks_per_group) {
|
|
// dump superblock and group descriptors and their backups
|
|
if (has_super(i)) {
|
|
// N.B. 1024 byte blocks are special
|
|
PUT(((uint64_t)pos * blocksize) + ((0 == i && 1024 != blocksize) ? 1024 : 0),
|
|
sb, 1024);
|
|
PUT(((uint64_t)pos * blocksize) + blocksize,
|
|
gd, group_desc_blocks * blocksize);
|
|
}
|
|
}
|
|
|
|
// zero boot sectors
|
|
memset(buf, 0, blocksize);
|
|
// Disabled: standard mke2fs doesn't do this, and
|
|
// on SPARC this destroys Sun disklabel.
|
|
// Users who need/want zeroing can easily do it with dd.
|
|
//PUT(0, buf, 1024); // N.B. 1024 <= blocksize, so buf[0..1023] contains zeros
|
|
|
|
// zero inode tables
|
|
for (i = 0; i < ngroups; ++i)
|
|
for (n = 0; n < inode_table_blocks; ++n)
|
|
PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize,
|
|
buf, blocksize);
|
|
|
|
// prepare directory inode
|
|
inode = (struct ext2_inode *)buf;
|
|
STORE_LE(inode->i_mode, S_IFDIR | S_IRWXU | S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH);
|
|
STORE_LE(inode->i_mtime, timestamp);
|
|
STORE_LE(inode->i_atime, timestamp);
|
|
STORE_LE(inode->i_ctime, timestamp);
|
|
STORE_LE(inode->i_size, blocksize);
|
|
// inode->i_blocks stores the number of 512 byte data blocks
|
|
// (512, because it goes directly to struct stat without scaling)
|
|
STORE_LE(inode->i_blocks, blocksize / 512);
|
|
|
|
// dump root dir inode
|
|
STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this inode
|
|
STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks);
|
|
PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * inodesize,
|
|
buf, inodesize);
|
|
|
|
// dump lost+found dir inode
|
|
STORE_LE(inode->i_links_count, 2); // both "/lost+found" and "/lost+found/." point to this inode
|
|
STORE_LE(inode->i_size, lost_and_found_blocks * blocksize);
|
|
STORE_LE(inode->i_blocks, (lost_and_found_blocks * blocksize) / 512);
|
|
n = FETCH_LE32(inode->i_block[0]) + 1;
|
|
for (i = 0; i < lost_and_found_blocks; ++i)
|
|
STORE_LE(inode->i_block[i], i + n); // use next block
|
|
//bb_error_msg("LAST BLOCK USED[%u]", i + n);
|
|
PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_GOOD_OLD_FIRST_INO-1) * inodesize,
|
|
buf, inodesize);
|
|
|
|
// dump directories
|
|
memset(buf, 0, blocksize);
|
|
dir = (struct ext2_dir *)buf;
|
|
|
|
// dump 2nd+ blocks of "/lost+found"
|
|
STORE_LE(dir->rec_len1, blocksize); // e2fsck 1.41.4 compat (1.41.9 does not need this)
|
|
for (i = 1; i < lost_and_found_blocks; ++i)
|
|
PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1+i) * blocksize,
|
|
buf, blocksize);
|
|
|
|
// dump 1st block of "/lost+found"
|
|
STORE_LE(dir->inode1, EXT2_GOOD_OLD_FIRST_INO);
|
|
STORE_LE(dir->rec_len1, 12);
|
|
STORE_LE(dir->name_len1, 1);
|
|
STORE_LE(dir->file_type1, EXT2_FT_DIR);
|
|
dir->name1[0] = '.';
|
|
STORE_LE(dir->inode2, EXT2_ROOT_INO);
|
|
STORE_LE(dir->rec_len2, blocksize - 12);
|
|
STORE_LE(dir->name_len2, 2);
|
|
STORE_LE(dir->file_type2, EXT2_FT_DIR);
|
|
dir->name2[0] = '.'; dir->name2[1] = '.';
|
|
PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1) * blocksize, buf, blocksize);
|
|
|
|
// dump root dir block
|
|
STORE_LE(dir->inode1, EXT2_ROOT_INO);
|
|
STORE_LE(dir->rec_len2, 12);
|
|
STORE_LE(dir->inode3, EXT2_GOOD_OLD_FIRST_INO);
|
|
STORE_LE(dir->rec_len3, blocksize - 12 - 12);
|
|
STORE_LE(dir->name_len3, 10);
|
|
STORE_LE(dir->file_type3, EXT2_FT_DIR);
|
|
strcpy(dir->name3, "lost+found");
|
|
PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 0) * blocksize, buf, blocksize);
|
|
|
|
// cleanup
|
|
if (ENABLE_FEATURE_CLEAN_UP) {
|
|
free(buf);
|
|
free(gd);
|
|
free(sb);
|
|
}
|
|
|
|
xclose(fd);
|
|
return EXIT_SUCCESS;
|
|
}
|