mkfs_ext2: make it able to create images larger than 4G
function old new delta mkfs_ext2_main 1904 2145 +241 has_super 29 23 -6 PUT 52 40 -12 packed_usage 26807 26792 -15 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 1/3 up/down: 241/-33) Total: 208 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
parent
f37eb3999b
commit
77da1cae94
@ -2717,11 +2717,12 @@
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"[-b BLK_SIZE] " \
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/* "[-f fragment-size] [-g blocks-per-group] " */ \
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"[-i BYTES_PER_INODE] " \
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/* "[-j] [-J journal-options] [-N number-of-inodes] [-n] " */ \
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/* "[-j] [-J journal-options] [-N number-of-inodes] " */ \
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"[-m RESERVED_PERCENT] " \
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/* "[-o creator-os] [-O feature[,...]] [-q] " */ \
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/* "[r fs-revision-level] [-E extended-options] [-v] [-F] " */ \
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"[-L LABEL] " \
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"[-n] " \
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/* "[-M last-mounted-directory] [-S] [-T filesystem-type] " */ \
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"DEVICE [BLK_COUNT]"
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#define mkfs_ext2_full_usage "\n" \
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@ -2738,7 +2739,7 @@
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"\n -L LBL Volume label" \
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"\n -m PERCENT Percent of blocks to reserve for admin" \
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/* "\n -M dir Set last mounted directory" */ \
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/* "\n -n Don't actually create anything" */ \
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"\n -n Dry run" \
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/* "\n -N num Number of inodes to create" */ \
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/* "\n -o os Set the 'creator os' field" */ \
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/* "\n -O features Dir_index/filetype/has_journal/journal_dev/sparse_super" */ \
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@ -77,33 +77,18 @@ static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32
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{
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uint32_t i;
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memset(bitmap, 0, blocksize);
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i = start/8;
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i = start / 8;
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memset(bitmap, 0xFF, i);
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bitmap[i] = 0xFF >> (8-(start&7));
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//bb_info_msg("ALLOC: [%u][%u][%u]: [%u]:=[%x]", blocksize, start, end, blocksize - end/8 - 1, (uint8_t)(0xFF << (8-(end&7))));
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i = end/8;
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bitmap[blocksize - i - 1] = 0xFF << (8-(end&7));
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i = end / 8;
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bitmap[blocksize - i - 1] = 0xFF << (8 - (end & 7));
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memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here!
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}
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#if 0
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// TODO: get rid of FPU
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static bool is_power_of(uint32_t x, uint16_t n)
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{
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// return (!(x % n) && is_power_of(x / n, n));
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double z = logf(x)/logf(n);
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return (z == (int)z);
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}
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static uint32_t has_super(uint32_t x)
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{
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return (0 == x || 1 == x || is_power_of(x, 3) || is_power_of(x, 5) || is_power_of(x, 7));
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}
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#else
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static uint32_t has_super(uint32_t x)
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{
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// 0, 1 and powers of 3, 5, 7 up to 2^32 limit
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static const uint32_t supers[] = {
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0, 1, 3, 5, 7, 9, 25, 27, 49, 81, 125, 243, 343, 625, 729,
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2187, 2401, 3125, 6561, 15625, 16807, 19683, 59049, 78125,
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@ -112,16 +97,15 @@ static uint32_t has_super(uint32_t x)
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48828125, 129140163, 244140625, 282475249, 387420489,
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1162261467, 1220703125, 1977326743, 3486784401/* >2^31 */,
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};
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const uint32_t *sp = supers + ARRAY_SIZE(supers)-1;
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const uint32_t *sp = supers + ARRAY_SIZE(supers);
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while (1) {
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sp--;
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if (x == *sp)
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return 1;
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if (0 == *sp)
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if (x > *sp)
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return 0;
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sp--;
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}
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}
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#endif
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/* Standard mke2fs 1.41.9:
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* Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size]
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@ -154,7 +138,7 @@ enum {
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OPT_T = 1 << 17,
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OPT_U = 1 << 18,
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OPT_j = 1 << 19,
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OPT_n = 1 << 20,
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OPT_n = 1 << 20, // dry run: do not write anything
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OPT_q = 1 << 21,
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OPT_v = 1 << 22,
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OPT_F = 1 << 23,
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@ -166,17 +150,16 @@ enum {
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static void PUT(uint64_t off, void *buf, uint32_t size)
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{
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if (!(option_mask32 & OPT_n)) {
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xlseek(fd, off, SEEK_SET);
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xwrite(fd, buf, size);
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}
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// bb_info_msg("PUT[%llu]:[%u]", off, size);
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xlseek(fd, off, SEEK_SET);
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xwrite(fd, buf, size);
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}
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int mkfs_ext2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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{
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unsigned i, pos, n;
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unsigned bs, blocksize;
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unsigned bs, blocksize, blocksize_log2;
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unsigned nreserved = 5;
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uint32_t nblocks;
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uint32_t ngroups;
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@ -235,7 +218,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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// TODO: 0/5 info printing
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// TODO: 2/5 bigendianness! Spot where it comes to play! sb->, gd->
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// TODO: 2/5 reserved GDT: how to mark but not allocate?
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// TODO: 0/5 dir_index?
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// TODO: 3/5 dir_index?
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// fill the superblock
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sb = xzalloc(blocksize);
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@ -243,13 +226,14 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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sb->s_magic = EXT2_SUPER_MAGIC;
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sb->s_inode_size = sizeof(*inode);
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sb->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
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sb->s_log_block_size = sb->s_log_frag_size = int_log2(blocksize >> EXT2_MIN_BLOCK_LOG_SIZE);
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blocksize_log2 = int_log2(blocksize);
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sb->s_log_block_size = sb->s_log_frag_size = blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE;
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// first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then
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// the first block available for data is 1, otherwise 0
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first_data_block = sb->s_first_data_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
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// block and inode bitmaps occupy no more than one block, so maximum number of blocks is
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// number of bits in one block, i.e. 8*blocksize
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nblocks_per_group = sb->s_blocks_per_group = sb->s_frags_per_group = sb->s_inodes_per_group = 8*blocksize;
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nblocks_per_group = sb->s_blocks_per_group = sb->s_frags_per_group = sb->s_inodes_per_group = 8 * blocksize;
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timestamp = time(NULL);
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sb->s_mkfs_time = sb->s_wtime = sb->s_lastcheck = timestamp;
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sb->s_state = 1;
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@ -266,10 +250,10 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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sb->s_feature_ro_compat = EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER;
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sb->s_flags = EXT2_FLAGS_SIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX;
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generate_uuid(sb->s_uuid);
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#if ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX
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sb->s_def_hash_version = EXT2_HASH_HALF_MD4;
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generate_uuid((uint8_t *)sb->s_hash_seed);
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#endif
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if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
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sb->s_def_hash_version = EXT2_HASH_HALF_MD4;
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generate_uuid((uint8_t *)sb->s_hash_seed);
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}
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/*
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* From e2fsprogs: add "jitter" to the superblock's check interval so that we
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* don't check all the filesystems at the same time. We use a
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@ -282,7 +266,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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if (argv[1]) {
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nblocks = xatou(argv[1]);
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} else {
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nblocks = ((uoff_t)xlseek(fd, 0, SEEK_END)) / blocksize;
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nblocks = (uoff_t)xlseek(fd, 0, SEEK_END) >> blocksize_log2;
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}
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sb->s_blocks_count = nblocks;
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@ -328,17 +312,17 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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if (nblocks < 3*1024)
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bytes_per_inode = 8192;
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}
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ninodes = nblocks / (bytes_per_inode / blocksize);
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ninodes = nblocks / (bytes_per_inode >> blocksize_log2);
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if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
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ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
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ninodes_per_group = div_roundup(ninodes, ngroups);
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if (ninodes_per_group < 16)
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ninodes_per_group = 16; // minimum number because the first 10 are reserved
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ninodes_per_group = 16; // minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
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// N.B. a block group can have no more than 8*blocksize = sb->s_inodes_per_group inodes
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if (ninodes_per_group > sb->s_inodes_per_group)
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ninodes_per_group = sb->s_inodes_per_group;
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// adjust inodes per group so they completely fill the inode table blocks in the descriptor
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ninodes_per_group = ((div_roundup(ninodes_per_group * EXT2_INODE_SIZE(sb), blocksize) * blocksize) / EXT2_INODE_SIZE(sb));
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ninodes_per_group = (div_roundup(ninodes_per_group * EXT2_INODE_SIZE(sb), blocksize) << blocksize_log2) / EXT2_INODE_SIZE(sb);
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// make sure the number of inodes per group is a multiple of 8
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ninodes_per_group &= ~7;
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sb->s_inodes_per_group = ninodes_per_group;// = div_roundup(ninodes_per_group * sb->s_inode_size, blocksize);
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@ -352,6 +336,52 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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if (opts & OPT_L)
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safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
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#if 1
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/* if (fs_param.s_blocks_count != s->s_blocks_count)
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fprintf(stderr, _("warning: %u blocks unused.\n\n"),
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fs_param.s_blocks_count - s->s_blocks_count);
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*/
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printf(
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"Filesystem label=%s\n"
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"OS type: Linux\n"
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"Block size=%u (log=%u)\n"
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"Fragment size=%u (log=%u)\n"
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"%u inodes, %u blocks\n"
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"%u blocks (%u%%) reserved for the super user\n"
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"First data block=%u\n"
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// "Maximum filesystem blocks=%lu\n"
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"%u block groups\n"
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"%u blocks per group, %u fragments per group\n"
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"%u inodes per group"
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, (char *)sb->s_volume_name
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, blocksize, sb->s_log_block_size
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, blocksize, sb->s_log_block_size
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, sb->s_inodes_count, sb->s_blocks_count
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, sb->s_r_blocks_count, nreserved
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, first_data_block
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// , (rgdtsz + gdtsz) * EXT2_DESC_PER_BLOCK(sb) * nblocks_per_group
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, ngroups
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, nblocks_per_group, nblocks_per_group
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, ninodes_per_group
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);
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{
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const char *fmt = "\nSuperblock backups stored on blocks: %u";
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pos = first_data_block;
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for (i = 1; i < ngroups; i++) {
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pos += nblocks_per_group;
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if (has_super(i)) {
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printf(fmt, (unsigned)pos);
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fmt = ", %u";
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}
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}
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}
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bb_putchar('\n');
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#endif
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if (opts & OPT_n)
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return EXIT_SUCCESS;
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// fill group descriptors
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gd = xzalloc((gdtsz + rgdtsz) * blocksize);
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sb->s_free_blocks_count = 0;
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@ -365,8 +395,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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gd[i].bg_inode_table = overhead + 2;
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overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
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gd[i].bg_free_inodes_count = ninodes_per_group;
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// N.B. both root and lost+found dirs are within the first block group, thus +2
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//gd[i].bg_used_dirs_count = 0;
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// N.B. both root and lost+found dirs are within the first block group, thus +2
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if (0 == i) {
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overhead += 2;
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gd[i].bg_used_dirs_count = 2;
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@ -383,6 +413,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
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// dump filesystem skeleton structures
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// printf("Writing superblocks and filesystem accounting information: ");
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buf = xmalloc(blocksize);
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for (i = 0, pos = first_data_block; i < ngroups; i++, pos += nblocks_per_group) {
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uint32_t overhead = has_super(i) ? (1/*sb*/ + gdtsz + rgdtsz) : 0;
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@ -391,28 +422,30 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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// dump superblock and group descriptors and their backups
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if (overhead) { // N.B. in fact, we want (has_super(i)) condition, but it is equal to (overhead != 0) and is cheaper
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//bb_info_msg("SUPER@[%d]", pos);
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// N.B. 1024 byte blocks are special
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PUT(blocksize * pos + ((0 == i && 0 == first_data_block) ? 1024 : 0), sb, blocksize);
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PUT(blocksize * pos + blocksize, gd, (gdtsz + rgdtsz) * blocksize);
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PUT(((uint64_t)pos << blocksize_log2) + ((0 == i && 0 == first_data_block) ? 1024 : 0), sb, 1024);//blocksize);
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PUT(((uint64_t)pos << blocksize_log2) + blocksize, gd, (gdtsz + rgdtsz) * blocksize);
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}
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start = overhead + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
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if (i == 0)
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start += 2; // for / and /lost+found
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start += 2; // for "/" and "/lost+found"
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end = nblocks_per_group - (start + gd[i].bg_free_blocks_count);
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// mark preallocated blocks as allocated
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allocate(buf, blocksize, start, end);
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// dump block bitmap
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PUT((pos + overhead) * blocksize, buf, blocksize);
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PUT((uint64_t)(pos + overhead) * blocksize, buf, blocksize);
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// mark preallocated inodes as allocated
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allocate(buf, blocksize,
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ninodes_per_group - gd[i].bg_free_inodes_count,
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8*blocksize - ninodes_per_group
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8 * blocksize - ninodes_per_group
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);
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// dump inode bitmap
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PUT((pos + overhead + 1) * blocksize, buf, blocksize);
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//PUT((uint64_t)(pos + overhead + 1) * blocksize, buf, blocksize);
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//but it's right after block bitmap, so we can just:
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xwrite(fd, buf, blocksize);
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}
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// zero boot sectors
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@ -421,12 +454,13 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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// zero inode tables
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for (i = 0; i < ngroups; ++i)
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for (n = 0; n < itsz; ++n)
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PUT((gd[i].bg_inode_table + n) * blocksize, buf, blocksize);
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PUT((uint64_t)(gd[i].bg_inode_table + n) * blocksize, buf, blocksize);
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// prepare directory inode
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inode = (struct ext2_inode *)buf;
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STORE_LE(inode->i_mode, S_IFDIR | S_IRWXU | S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH);
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inode->i_mtime = inode->i_atime = timestamp;
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STORE_LE(inode->i_mtime, timestamp);
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STORE_LE(inode->i_atime, timestamp);
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STORE_LE(inode->i_ctime, timestamp);
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STORE_LE(inode->i_size, blocksize);
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// N.B. inode->i_blocks stores the number of 512 byte data blocks. Why on Earth?!
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@ -435,12 +469,12 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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// dump root dir inode
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STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this inode
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STORE_LE(inode->i_block[0], gd[0].bg_inode_table + itsz);
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PUT(gd[0].bg_inode_table * blocksize + (EXT2_ROOT_INO-1) * sizeof(*inode), buf, sizeof(*inode));
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PUT(((uint64_t)gd[0].bg_inode_table << blocksize_log2) + (EXT2_ROOT_INO-1) * sizeof(*inode), buf, sizeof(*inode));
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// dump lost+found dir inode
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STORE_LE(inode->i_links_count, 2); // both "/lost+found" and "/lost+found/." point to this inode
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STORE_LE(inode->i_block[0], inode->i_block[0]+1); // use next block //= gd[0].bg_inode_table + itsz + 1;
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PUT(gd[0].bg_inode_table * blocksize + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
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PUT(((uint64_t)gd[0].bg_inode_table << blocksize_log2) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
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// dump directories
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memset(buf, 0, blocksize);
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@ -457,7 +491,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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STORE_LE(dir->name_len2, 2);
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STORE_LE(dir->file_type2, EXT2_FT_DIR);
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dir->name2[0] = '.'; dir->name2[1] = '.';
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PUT((gd[0].bg_inode_table + itsz + 1) * blocksize, buf, blocksize);
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PUT((uint64_t)(gd[0].bg_inode_table + itsz + 1) * blocksize, buf, blocksize);
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// dump root dir block
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STORE_LE(dir->inode1, EXT2_ROOT_INO);
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@ -467,15 +501,21 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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STORE_LE(dir->name_len3, 10);
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STORE_LE(dir->file_type3, EXT2_FT_DIR);
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strcpy(dir->name3, "lost+found");
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PUT((gd[0].bg_inode_table + itsz + 0) * blocksize, buf, blocksize);
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PUT((uint64_t)(gd[0].bg_inode_table + itsz + 0) * blocksize, buf, blocksize);
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// bb_info_msg("done\n"
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// "This filesystem will be automatically checked every %u mounts or\n"
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// "%u days, whichever comes first. Use tune2fs -c or -i to override.",
|
||||
// sb->s_max_mnt_count, sb->s_checkinterval / (3600 * 24)
|
||||
// );
|
||||
|
||||
// cleanup
|
||||
if (ENABLE_FEATURE_CLEAN_UP) {
|
||||
free(buf);
|
||||
free(gd);
|
||||
free(sb);
|
||||
close(fd);
|
||||
}
|
||||
|
||||
xclose(fd);
|
||||
return EXIT_SUCCESS;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user