1 /* vi: set sw=4 ts=4: */
3 * mkfs_ext2: utility to create EXT2 filesystem
4 * inspired by genext2fs
6 * Busybox'ed (2009) by Vladimir Dronnikov <dronnikov@gmail.com>
8 * Licensed under GPLv2, see file LICENSE in this source tree.
11 //usage:#define mkfs_ext2_trivial_usage
13 /* //usage: "[-c|-l filename] " */
14 //usage: "[-b BLK_SIZE] "
15 /* //usage: "[-f fragment-size] [-g blocks-per-group] " */
16 //usage: "[-i INODE_RATIO] [-I INODE_SIZE] "
17 /* //usage: "[-j] [-J journal-options] [-N number-of-inodes] " */
18 //usage: "[-m RESERVED_PERCENT] "
19 /* //usage: "[-o creator-os] [-O feature[,...]] [-q] " */
20 /* //usage: "[r fs-revision-level] [-E extended-options] [-v] [-F] " */
21 //usage: "[-L LABEL] "
22 /* //usage: "[-M last-mounted-directory] [-S] [-T filesystem-type] " */
23 //usage: "BLOCKDEV [KBYTES]"
24 //usage:#define mkfs_ext2_full_usage "\n\n"
25 //usage: " -b BLK_SIZE Block size, bytes"
26 /* //usage: "\n -c Check device for bad blocks" */
27 /* //usage: "\n -E opts Set extended options" */
28 /* //usage: "\n -f size Fragment size in bytes" */
29 //usage: "\n -F Force"
30 /* //usage: "\n -g N Number of blocks in a block group" */
31 //usage: "\n -i RATIO Max number of files is filesystem_size / RATIO"
32 //usage: "\n -I BYTES Inode size (min 128)"
33 /* //usage: "\n -j Create a journal (ext3)" */
34 /* //usage: "\n -J opts Set journal options (size/device)" */
35 /* //usage: "\n -l file Read bad blocks list from file" */
36 //usage: "\n -L LBL Volume label"
37 //usage: "\n -m PERCENT Percent of blocks to reserve for admin"
38 /* //usage: "\n -M dir Set last mounted directory" */
39 //usage: "\n -n Dry run"
40 /* //usage: "\n -N N Number of inodes to create" */
41 /* //usage: "\n -o os Set the 'creator os' field" */
42 /* //usage: "\n -O features Dir_index/filetype/has_journal/journal_dev/sparse_super" */
43 /* //usage: "\n -q Quiet" */
44 /* //usage: "\n -r rev Set filesystem revision" */
45 /* //usage: "\n -S Write superblock and group descriptors only" */
46 /* //usage: "\n -T fs-type Set usage type (news/largefile/largefile4)" */
47 /* //usage: "\n -v Verbose" */
52 * Work around linux/ext2_fs.h breakage.
53 * See https://bugzilla.kernel.org/show_bug.cgi?id=42986.
55 typedef mode_t bb__umode_t;
56 #define umode_t bb__umode_t
57 #include <linux/ext2_fs.h>
59 #define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
60 #define ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX 1
63 #define s_reserved_gdt_blocks s_padding1
64 #define s_mkfs_time s_reserved[0]
65 #define s_flags s_reserved[22]
67 #define EXT2_HASH_HALF_MD4 1
68 #define EXT2_FLAGS_SIGNED_HASH 0x0001
69 #define EXT2_FLAGS_UNSIGNED_HASH 0x0002
72 char BUG_wrong_field_size(void);
73 #define STORE_LE(field, value) \
75 if (sizeof(field) == 4) \
76 field = SWAP_LE32(value); \
77 else if (sizeof(field) == 2) \
78 field = SWAP_LE16(value); \
79 else if (sizeof(field) == 1) \
82 BUG_wrong_field_size(); \
85 #define FETCH_LE32(field) \
86 (sizeof(field) == 4 ? SWAP_LE32(field) : BUG_wrong_field_size())
88 // All fields are little-endian
107 static unsigned int_log2(unsigned arg)
110 while ((arg >>= 1) != 0)
115 // taken from mkfs_minix.c. libbb candidate?
116 // "uint32_t size", since we never use it for anything >32 bits
117 static uint32_t div_roundup(uint32_t size, uint32_t n)
119 // Overflow-resistant
120 uint32_t res = size / n;
126 static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32_t end)
130 //bb_info_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)));
131 memset(bitmap, 0, blocksize);
133 memset(bitmap, 0xFF, i);
134 bitmap[i] = (1 << (start & 7)) - 1; //0..7 => 00000000..01111111
136 bitmap[blocksize - i - 1] |= 0x7F00 >> (end & 7); //0..7 => 00000000..11111110
137 memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here!
140 static uint32_t has_super(uint32_t x)
142 // 0, 1 and powers of 3, 5, 7 up to 2^32 limit
143 static const uint32_t supers[] = {
144 0, 1, 3, 5, 7, 9, 25, 27, 49, 81, 125, 243, 343, 625, 729,
145 2187, 2401, 3125, 6561, 15625, 16807, 19683, 59049, 78125,
146 117649, 177147, 390625, 531441, 823543, 1594323, 1953125,
147 4782969, 5764801, 9765625, 14348907, 40353607, 43046721,
148 48828125, 129140163, 244140625, 282475249, 387420489,
149 1162261467, 1220703125, 1977326743, 3486784401/* >2^31 */,
151 const uint32_t *sp = supers + ARRAY_SIZE(supers);
161 #define fd 3 /* predefined output descriptor */
163 static void PUT(uint64_t off, void *buf, uint32_t size)
165 // bb_info_msg("PUT[%llu]:[%u]", off, size);
166 xlseek(fd, off, SEEK_SET);
167 xwrite(fd, buf, size);
170 // 128 and 256-byte inodes:
171 // 128-byte inode is described by struct ext2_inode.
172 // 256-byte one just has these fields appended:
173 // __u16 i_extra_isize;
175 // __u32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */
176 // __u32 i_mtime_extra; /* extra Modification time (nsec << 2 | epoch) */
177 // __u32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */
178 // __u32 i_crtime; /* File creation time */
179 // __u32 i_crtime_extra; /* extra File creation time (nsec << 2 | epoch)*/
180 // __u32 i_version_hi; /* high 32 bits for 64-bit version */
181 // the rest is padding.
183 // linux/ext2_fs.h has "#define i_size_high i_dir_acl" which suggests that even
184 // 128-byte inode is capable of describing large files (i_dir_acl is meaningful
185 // only for directories, which never need i_size_high).
187 // Standard mke2fs creates a filesystem with 256-byte inodes if it is
188 // bigger than 0.5GB.
190 // Standard mke2fs 1.41.9:
191 // Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size]
192 // [-i bytes-per-inode] [-I inode-size] [-J journal-options]
193 // [-G meta group size] [-N number-of-inodes]
194 // [-m reserved-blocks-percentage] [-o creator-os]
195 // [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
196 // [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
197 // [-T fs-type] [-U UUID] [-jnqvFSV] device [blocks-count]
199 // Options not commented below are taken but silently ignored:
203 OPT_b = 1 << 2, // block size, in bytes
205 OPT_i = 1 << 4, // bytes per inode
206 OPT_I = 1 << 5, // custom inode size, in bytes
210 OPT_m = 1 << 9, // percentage of blocks reserved for superuser
213 OPT_L = 1 << 12, // label
221 OPT_n = 1 << 20, // dry run: do not write anything
226 //OPT_V = 1 << 25, // -V version. bbox applets don't support that
229 int mkfs_ext2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
230 int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
234 unsigned blocksize, blocksize_log2;
235 unsigned inodesize, user_inodesize;
236 unsigned reserved_percent = 5;
237 unsigned long long kilobytes;
238 uint32_t nblocks, nblocks_full;
241 uint32_t bytes_per_inode;
242 uint32_t first_block;
243 uint32_t inodes_per_group;
244 uint32_t group_desc_blocks;
245 uint32_t inode_table_blocks;
246 uint32_t lost_and_found_blocks;
248 const char *label = "";
250 struct ext2_super_block *sb; // superblock
251 struct ext2_group_desc *gd; // group descriptors
252 struct ext2_inode *inode;
253 struct ext2_dir *dir;
256 // using global "option_mask32" instead of local "opts":
257 // we are register starved here
258 opt_complementary = "-1:b+:i+:I+:m+";
259 /*opts =*/ getopt32(argv, "cl:b:f:i:I:J:G:N:m:o:g:L:M:O:r:E:T:U:jnqvFS",
260 /*lbfi:*/ NULL, &bs, NULL, &bpi,
261 /*IJGN:*/ &user_inodesize, NULL, NULL, NULL,
262 /*mogL:*/ &reserved_percent, NULL, NULL, &label,
263 /*MOrE:*/ NULL, NULL, NULL, NULL,
265 argv += optind; // argv[0] -- device
267 // open the device, check the device is a block device
268 xmove_fd(xopen(argv[0], O_WRONLY), fd);
269 xfstat(fd, &st, argv[0]);
270 if (!S_ISBLK(st.st_mode) && !(option_mask32 & OPT_F))
271 bb_error_msg_and_die("%s: not a block device", argv[0]);
273 // check if it is mounted
274 // N.B. what if we format a file? find_mount_point will return false negative since
275 // it is loop block device which is mounted!
276 if (find_mount_point(argv[0], 0))
277 bb_error_msg_and_die("can't format mounted filesystem");
279 // get size in kbytes
280 kilobytes = get_volume_size_in_bytes(fd, argv[1], 1024, /*extend:*/ !(option_mask32 & OPT_n)) / 1024;
282 bytes_per_inode = 16384;
283 if (kilobytes < 512*1024)
284 bytes_per_inode = 4096;
285 if (kilobytes < 3*1024)
286 bytes_per_inode = 8192;
287 if (option_mask32 & OPT_i)
288 bytes_per_inode = bpi;
290 // Determine block size and inode size
291 // block size is a multiple of 1024
292 // inode size is a multiple of 128
294 inodesize = sizeof(struct ext2_inode); // 128
295 if (kilobytes >= 512*1024) { // mke2fs 1.41.9 compat
299 if (EXT2_MAX_BLOCK_SIZE > 4096) {
300 // kilobytes >> 22 == size in 4gigabyte chunks.
301 // if size >= 16k gigs, blocksize must be increased.
302 // Try "mke2fs -F image $((16 * 1024*1024*1024))"
303 while ((kilobytes >> 22) >= blocksize)
306 if (option_mask32 & OPT_b)
308 if (blocksize < EXT2_MIN_BLOCK_SIZE
309 || blocksize > EXT2_MAX_BLOCK_SIZE
310 || (blocksize & (blocksize - 1)) // not power of 2
312 bb_error_msg_and_die("blocksize %u is bad", blocksize);
314 // Do we have custom inode size?
315 if (option_mask32 & OPT_I) {
316 if (user_inodesize < sizeof(*inode)
317 || user_inodesize > blocksize
318 || (user_inodesize & (user_inodesize - 1)) // not power of 2
320 bb_error_msg("-%c is bad", 'I');
322 inodesize = user_inodesize;
326 if ((int32_t)bytes_per_inode < blocksize)
327 bb_error_msg_and_die("-%c is bad", 'i');
328 // number of bits in one block, i.e. 8*blocksize
329 #define blocks_per_group (8 * blocksize)
330 first_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
331 blocksize_log2 = int_log2(blocksize);
333 // Determine number of blocks
334 kilobytes >>= (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
336 if (nblocks != kilobytes)
337 bb_error_msg_and_die("block count doesn't fit in 32 bits");
338 #define kilobytes kilobytes_unused_after_this
339 // Experimentally, standard mke2fs won't work on images smaller than 60k
341 bb_error_msg_and_die("need >= 60 blocks");
343 // How many reserved blocks?
344 if (reserved_percent > 50)
345 bb_error_msg_and_die("-%c is bad", 'm');
346 nreserved = (uint64_t)nblocks * reserved_percent / 100;
348 // N.B. killing e2fsprogs feature! Unused blocks don't account in calculations
349 nblocks_full = nblocks;
351 // If last block group is too small, nblocks may be decreased in order
352 // to discard it, and control returns here to recalculate some
354 // Note: blocksize and bytes_per_inode are never recalculated.
356 // N.B. a block group can have no more than blocks_per_group blocks
357 ngroups = div_roundup(nblocks - first_block, blocks_per_group);
359 group_desc_blocks = div_roundup(ngroups, blocksize / sizeof(*gd));
360 // TODO: reserved blocks must be marked as such in the bitmaps,
361 // or resulting filesystem is corrupt
362 if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) {
364 * From e2fsprogs: Calculate the number of GDT blocks to reserve for online
366 * The absolute maximum number of GDT blocks we can reserve is determined by
367 * the number of block pointers that can fit into a single block.
368 * We set it at 1024x the current filesystem size, or
369 * the upper block count limit (2^32), whichever is lower.
371 uint32_t reserved_group_desc_blocks = 0xFFFFFFFF; // maximum block number
372 if (nblocks < reserved_group_desc_blocks / 1024)
373 reserved_group_desc_blocks = nblocks * 1024;
374 reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks - first_block, blocks_per_group);
375 reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks, blocksize / sizeof(*gd)) - group_desc_blocks;
376 if (reserved_group_desc_blocks > blocksize / sizeof(uint32_t))
377 reserved_group_desc_blocks = blocksize / sizeof(uint32_t);
378 //TODO: STORE_LE(sb->s_reserved_gdt_blocks, reserved_group_desc_blocks);
379 group_desc_blocks += reserved_group_desc_blocks;
383 // N.B. e2fsprogs does as follows!
384 uint32_t overhead, remainder;
385 // ninodes is the max number of inodes in this filesystem
386 uint32_t ninodes = ((uint64_t) nblocks_full * blocksize) / bytes_per_inode;
387 if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
388 ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
389 inodes_per_group = div_roundup(ninodes, ngroups);
390 // minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
391 if (inodes_per_group < 16)
392 inodes_per_group = 16;
393 // a block group can't have more inodes than blocks
394 if (inodes_per_group > blocks_per_group)
395 inodes_per_group = blocks_per_group;
396 // adjust inodes per group so they completely fill the inode table blocks in the descriptor
397 inodes_per_group = (div_roundup(inodes_per_group * inodesize, blocksize) * blocksize) / inodesize;
398 // make sure the number of inodes per group is a multiple of 8
399 inodes_per_group &= ~7;
400 inode_table_blocks = div_roundup(inodes_per_group * inodesize, blocksize);
402 // to be useful, lost+found should occupy at least 2 blocks (but not exceeding 16*1024 bytes),
403 // and at most EXT2_NDIR_BLOCKS. So reserve these blocks right now
404 /* Or e2fsprogs comment verbatim (what does it mean?):
405 * Ensure that lost+found is at least 2 blocks, so we always
406 * test large empty blocks for big-block filesystems. */
407 lost_and_found_blocks = MIN(EXT2_NDIR_BLOCKS, 16 >> (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE));
409 // the last group needs more attention: isn't it too small for possible overhead?
410 overhead = (has_super(ngroups - 1) ? (1/*sb*/ + group_desc_blocks) : 0) + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
411 remainder = (nblocks - first_block) % blocks_per_group;
412 ////can't happen, nblocks >= 60 guarantees this
413 ////if ((1 == ngroups)
415 //// && (remainder < overhead + 1/* "/" */ + lost_and_found_blocks)
417 //// bb_error_msg_and_die("way small device");
420 // Standard mke2fs uses 50. Looks like a bug in our calculation
421 // of "remainder" or "overhead" - we don't match standard mke2fs
422 // when we transition from one group to two groups
423 // (a bit after 8M image size), but it works for two->three groups
424 // transition (at 16M).
425 if (remainder && (remainder < overhead + 50)) {
426 //bb_info_msg("CHOP[%u]", remainder);
427 nblocks -= remainder;
432 if (nblocks_full - nblocks)
433 printf("warning: %u blocks unused\n\n", nblocks_full - nblocks);
435 "Filesystem label=%s\n"
437 "Block size=%u (log=%u)\n"
438 "Fragment size=%u (log=%u)\n"
439 "%u inodes, %u blocks\n"
440 "%u blocks (%u%%) reserved for the super user\n"
441 "First data block=%u\n"
442 "Maximum filesystem blocks=%u\n"
444 "%u blocks per group, %u fragments per group\n"
445 "%u inodes per group"
447 , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
448 , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
449 , inodes_per_group * ngroups, nblocks
450 , nreserved, reserved_percent
452 , group_desc_blocks * (blocksize / (unsigned)sizeof(*gd)) * blocks_per_group
454 , blocks_per_group, blocks_per_group
458 const char *fmt = "\nSuperblock backups stored on blocks:\n"
461 for (i = 1; i < ngroups; i++) {
462 pos += blocks_per_group;
464 printf(fmt, (unsigned)pos);
471 if (option_mask32 & OPT_n) {
472 if (ENABLE_FEATURE_CLEAN_UP)
477 // TODO: 3/5 refuse if mounted
478 // TODO: 4/5 compat options
479 // TODO: 1/5 sanity checks
480 // TODO: 0/5 more verbose error messages
481 // TODO: 4/5 bigendianness: recheck, wait for ARM reporters
482 // TODO: 2/5 reserved GDT: how to mark but not allocate?
483 // TODO: 3/5 dir_index?
485 // fill the superblock
487 STORE_LE(sb->s_rev_level, EXT2_DYNAMIC_REV); // revision 1 filesystem
488 STORE_LE(sb->s_magic, EXT2_SUPER_MAGIC);
489 STORE_LE(sb->s_inode_size, inodesize);
490 // set "Required extra isize" and "Desired extra isize" fields to 28
491 if (inodesize != sizeof(*inode))
492 STORE_LE(sb->s_reserved[21], 0x001C001C);
493 STORE_LE(sb->s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
494 STORE_LE(sb->s_log_block_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
495 STORE_LE(sb->s_log_frag_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
496 // first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then
497 // the first block is 1, otherwise 0
498 STORE_LE(sb->s_first_data_block, first_block);
499 // block and inode bitmaps occupy no more than one block, so maximum number of blocks is
500 STORE_LE(sb->s_blocks_per_group, blocks_per_group);
501 STORE_LE(sb->s_frags_per_group, blocks_per_group);
503 STORE_LE(sb->s_blocks_count, nblocks);
504 // reserve blocks for superuser
505 STORE_LE(sb->s_r_blocks_count, nreserved);
507 STORE_LE(sb->s_inodes_per_group, inodes_per_group);
508 STORE_LE(sb->s_inodes_count, inodes_per_group * ngroups);
509 STORE_LE(sb->s_free_inodes_count, inodes_per_group * ngroups - EXT2_GOOD_OLD_FIRST_INO);
511 timestamp = time(NULL);
512 STORE_LE(sb->s_mkfs_time, timestamp);
513 STORE_LE(sb->s_wtime, timestamp);
514 STORE_LE(sb->s_lastcheck, timestamp);
515 // misc. Values are chosen to match mke2fs 1.41.9
516 STORE_LE(sb->s_state, 1); // TODO: what's 1?
517 STORE_LE(sb->s_creator_os, EXT2_OS_LINUX);
518 STORE_LE(sb->s_checkinterval, 24*60*60 * 180); // 180 days
519 STORE_LE(sb->s_errors, EXT2_ERRORS_DEFAULT);
520 // mke2fs 1.41.9 also sets EXT3_FEATURE_COMPAT_RESIZE_INODE
521 // and if >= 0.5GB, EXT3_FEATURE_RO_COMPAT_LARGE_FILE.
522 // we use values which match "mke2fs -O ^resize_inode":
523 // in this case 1.41.9 never sets EXT3_FEATURE_RO_COMPAT_LARGE_FILE.
524 STORE_LE(sb->s_feature_compat, EXT2_FEATURE_COMPAT_SUPP
525 | (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
526 | (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
528 STORE_LE(sb->s_feature_incompat, EXT2_FEATURE_INCOMPAT_FILETYPE);
529 STORE_LE(sb->s_feature_ro_compat, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
530 STORE_LE(sb->s_flags, EXT2_FLAGS_UNSIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX);
531 generate_uuid(sb->s_uuid);
532 if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
533 STORE_LE(sb->s_def_hash_version, EXT2_HASH_HALF_MD4);
534 generate_uuid((uint8_t *)sb->s_hash_seed);
537 * From e2fsprogs: add "jitter" to the superblock's check interval so that we
538 * don't check all the filesystems at the same time. We use a
539 * kludgy hack of using the UUID to derive a random jitter value.
541 STORE_LE(sb->s_max_mnt_count,
542 EXT2_DFL_MAX_MNT_COUNT
543 + (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));
546 safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
548 // calculate filesystem skeleton structures
549 gd = xzalloc(group_desc_blocks * blocksize);
550 buf = xmalloc(blocksize);
551 sb->s_free_blocks_count = 0;
552 for (i = 0, pos = first_block, n = nblocks - first_block;
554 i++, pos += blocks_per_group, n -= blocks_per_group
556 uint32_t overhead = pos + (has_super(i) ? (1/*sb*/ + group_desc_blocks) : 0);
557 uint32_t free_blocks;
558 // fill group descriptors
559 STORE_LE(gd[i].bg_block_bitmap, overhead + 0);
560 STORE_LE(gd[i].bg_inode_bitmap, overhead + 1);
561 STORE_LE(gd[i].bg_inode_table, overhead + 2);
562 overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
563 gd[i].bg_free_inodes_count = inodes_per_group;
564 //STORE_LE(gd[i].bg_used_dirs_count, 0);
565 // N.B. both "/" and "/lost+found" are within the first block group
566 // "/" occupies 1 block, "/lost+found" occupies lost_and_found_blocks...
568 // ... thus increased overhead for the first block group ...
569 overhead += 1 + lost_and_found_blocks;
570 // ... and 2 used directories
571 STORE_LE(gd[i].bg_used_dirs_count, 2);
572 // well known reserved inodes belong to the first block too
573 gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO;
576 // cache free block count of the group
577 free_blocks = (n < blocks_per_group ? n : blocks_per_group) - overhead;
579 // mark preallocated blocks as allocated
580 //bb_info_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (free_blocks + overhead));
581 allocate(buf, blocksize,
582 // reserve "overhead" blocks
584 // mark unused trailing blocks
585 blocks_per_group - (free_blocks + overhead)
588 PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
589 STORE_LE(gd[i].bg_free_blocks_count, free_blocks);
591 // mark preallocated inodes as allocated
592 allocate(buf, blocksize,
593 // mark reserved inodes
594 inodes_per_group - gd[i].bg_free_inodes_count,
595 // mark unused trailing inodes
596 blocks_per_group - inodes_per_group
599 //PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
600 //but it's right after block bitmap, so we can just:
601 xwrite(fd, buf, blocksize);
602 STORE_LE(gd[i].bg_free_inodes_count, gd[i].bg_free_inodes_count);
604 // count overall free blocks
605 sb->s_free_blocks_count += free_blocks;
607 STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
609 // dump filesystem skeleton structures
610 // printf("Writing superblocks and filesystem accounting information: ");
611 for (i = 0, pos = first_block; i < ngroups; i++, pos += blocks_per_group) {
612 // dump superblock and group descriptors and their backups
614 // N.B. 1024 byte blocks are special
615 PUT(((uint64_t)pos * blocksize) + ((0 == i && 1024 != blocksize) ? 1024 : 0),
617 PUT(((uint64_t)pos * blocksize) + blocksize,
618 gd, group_desc_blocks * blocksize);
623 memset(buf, 0, blocksize);
624 // Disabled: standard mke2fs doesn't do this, and
625 // on SPARC this destroys Sun disklabel.
626 // Users who need/want zeroing can easily do it with dd.
627 //PUT(0, buf, 1024); // N.B. 1024 <= blocksize, so buf[0..1023] contains zeros
630 for (i = 0; i < ngroups; ++i)
631 for (n = 0; n < inode_table_blocks; ++n)
632 PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize,
635 // prepare directory inode
636 inode = (struct ext2_inode *)buf;
637 STORE_LE(inode->i_mode, S_IFDIR | S_IRWXU | S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH);
638 STORE_LE(inode->i_mtime, timestamp);
639 STORE_LE(inode->i_atime, timestamp);
640 STORE_LE(inode->i_ctime, timestamp);
641 STORE_LE(inode->i_size, blocksize);
642 // inode->i_blocks stores the number of 512 byte data blocks
643 // (512, because it goes directly to struct stat without scaling)
644 STORE_LE(inode->i_blocks, blocksize / 512);
646 // dump root dir inode
647 STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this inode
648 STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks);
649 PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * inodesize,
652 // dump lost+found dir inode
653 STORE_LE(inode->i_links_count, 2); // both "/lost+found" and "/lost+found/." point to this inode
654 STORE_LE(inode->i_size, lost_and_found_blocks * blocksize);
655 STORE_LE(inode->i_blocks, (lost_and_found_blocks * blocksize) / 512);
656 n = FETCH_LE32(inode->i_block[0]) + 1;
657 for (i = 0; i < lost_and_found_blocks; ++i)
658 STORE_LE(inode->i_block[i], i + n); // use next block
659 //bb_info_msg("LAST BLOCK USED[%u]", i + n);
660 PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_GOOD_OLD_FIRST_INO-1) * inodesize,
664 memset(buf, 0, blocksize);
665 dir = (struct ext2_dir *)buf;
667 // dump 2nd+ blocks of "/lost+found"
668 STORE_LE(dir->rec_len1, blocksize); // e2fsck 1.41.4 compat (1.41.9 does not need this)
669 for (i = 1; i < lost_and_found_blocks; ++i)
670 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1+i) * blocksize,
673 // dump 1st block of "/lost+found"
674 STORE_LE(dir->inode1, EXT2_GOOD_OLD_FIRST_INO);
675 STORE_LE(dir->rec_len1, 12);
676 STORE_LE(dir->name_len1, 1);
677 STORE_LE(dir->file_type1, EXT2_FT_DIR);
679 STORE_LE(dir->inode2, EXT2_ROOT_INO);
680 STORE_LE(dir->rec_len2, blocksize - 12);
681 STORE_LE(dir->name_len2, 2);
682 STORE_LE(dir->file_type2, EXT2_FT_DIR);
683 dir->name2[0] = '.'; dir->name2[1] = '.';
684 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1) * blocksize, buf, blocksize);
686 // dump root dir block
687 STORE_LE(dir->inode1, EXT2_ROOT_INO);
688 STORE_LE(dir->rec_len2, 12);
689 STORE_LE(dir->inode3, EXT2_GOOD_OLD_FIRST_INO);
690 STORE_LE(dir->rec_len3, blocksize - 12 - 12);
691 STORE_LE(dir->name_len3, 10);
692 STORE_LE(dir->file_type3, EXT2_FT_DIR);
693 strcpy(dir->name3, "lost+found");
694 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 0) * blocksize, buf, blocksize);
697 if (ENABLE_FEATURE_CLEAN_UP) {