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 tarball for details.
12 #include <linux/ext2_fs.h>
13 #include <sys/user.h> /* PAGE_SIZE */
15 # define PAGE_SIZE 4096
17 #include "volume_id/volume_id_internal.h"
19 #define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
20 #define ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX 1
23 #define s_reserved_gdt_blocks s_padding1
24 #define s_mkfs_time s_reserved[0]
25 #define s_flags s_reserved[22]
26 #define EXT2_HASH_HALF_MD4 1
27 #define EXT2_FLAGS_SIGNED_HASH 0x0001
29 // whiteout: for writable overlays
30 //#define LINUX_S_IFWHT 0160000
31 //#define EXT2_FEATURE_INCOMPAT_WHITEOUT 0x0020
34 char BUG_wrong_field_size(void);
35 #define STORE_LE(field, value) \
37 if (sizeof(field) == 4) \
38 field = cpu_to_le32(value); \
39 else if (sizeof(field) == 2) \
40 field = cpu_to_le16(value); \
41 else if (sizeof(field) == 1) \
44 BUG_wrong_field_size(); \
47 #define FETCH_LE32(field) \
48 (sizeof(field) == 4 ? cpu_to_le32(field) : BUG_wrong_field_size())
50 // All fields are little-endian
69 static unsigned int_log2(unsigned arg)
72 while ((arg >>= 1) != 0)
77 // taken from mkfs_minix.c. libbb candidate?
78 // "uint32_t size", since we never use it for anything >32 bits
79 static uint32_t div_roundup(uint32_t size, uint32_t n)
82 uint32_t res = size / n;
88 static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32_t end)
92 //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)));
93 memset(bitmap, 0, blocksize);
95 memset(bitmap, 0xFF, i);
96 bitmap[i] = (1 << (start & 7)) - 1; //0..7 => 00000000..01111111
98 bitmap[blocksize - i - 1] |= 0x7F00 >> (end & 7); //0..7 => 00000000..11111110
99 memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here!
102 static uint32_t has_super(uint32_t x)
104 // 0, 1 and powers of 3, 5, 7 up to 2^32 limit
105 static const uint32_t supers[] = {
106 0, 1, 3, 5, 7, 9, 25, 27, 49, 81, 125, 243, 343, 625, 729,
107 2187, 2401, 3125, 6561, 15625, 16807, 19683, 59049, 78125,
108 117649, 177147, 390625, 531441, 823543, 1594323, 1953125,
109 4782969, 5764801, 9765625, 14348907, 40353607, 43046721,
110 48828125, 129140163, 244140625, 282475249, 387420489,
111 1162261467, 1220703125, 1977326743, 3486784401/* >2^31 */,
113 const uint32_t *sp = supers + ARRAY_SIZE(supers);
123 #define fd 3 /* predefined output descriptor */
125 static void PUT(uint64_t off, void *buf, uint32_t size)
127 // bb_info_msg("PUT[%llu]:[%u]", off, size);
128 xlseek(fd, off, SEEK_SET);
129 xwrite(fd, buf, size);
132 // 128 and 256-byte inodes:
133 // 128-byte inode is described by struct ext2_inode.
134 // 256-byte one just has these fields appended:
135 // __u16 i_extra_isize;
137 // __u32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */
138 // __u32 i_mtime_extra; /* extra Modification time (nsec << 2 | epoch) */
139 // __u32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */
140 // __u32 i_crtime; /* File creation time */
141 // __u32 i_crtime_extra; /* extra File creation time (nsec << 2 | epoch)*/
142 // __u32 i_version_hi; /* high 32 bits for 64-bit version */
143 // the rest is padding.
145 // linux/ext2_fs.h has "#define i_size_high i_dir_acl" which suggests that even
146 // 128-byte inode is capable of describing large files (i_dir_acl is meaningful
147 // only for directories, which never need i_size_high).
149 // Standard mke2fs creates a filesystem with 256-byte inodes if it is
150 // bigger than 0.5GB. So far, we do not do this.
152 // Standard mke2fs 1.41.9:
153 // Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size]
154 // [-i bytes-per-inode] [-I inode-size] [-J journal-options]
155 // [-G meta group size] [-N number-of-inodes]
156 // [-m reserved-blocks-percentage] [-o creator-os]
157 // [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
158 // [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
159 // [-T fs-type] [-U UUID] [-jnqvFSV] device [blocks-count]
161 // Options not commented below are taken but silently ignored:
165 OPT_b = 1 << 2, // block size, in bytes
167 OPT_i = 1 << 4, // bytes per inode
172 OPT_m = 1 << 9, // percentage of blocks reserved for superuser
175 OPT_L = 1 << 12, // label
183 OPT_n = 1 << 20, // dry run: do not write anything
188 //OPT_V = 1 << 25, // -V version. bbox applets don't support that
191 int mkfs_ext2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
192 int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
196 unsigned blocksize, blocksize_log2;
197 unsigned reserved_percent = 5;
198 unsigned long long kilobytes;
199 uint32_t nblocks, nblocks_full;
202 uint32_t bytes_per_inode;
203 uint32_t first_block;
204 uint32_t inodes_per_group;
205 uint32_t group_desc_blocks;
206 uint32_t inode_table_blocks;
207 uint32_t lost_and_found_blocks;
210 const char *label = "";
212 struct ext2_super_block *sb; // superblock
213 struct ext2_group_desc *gd; // group descriptors
214 struct ext2_inode *inode;
215 struct ext2_dir *dir;
218 opt_complementary = "-1:b+:m+:i+";
219 opts = getopt32(argv, "cl:b:f:i:I:J:G:N:m:o:g:L:M:O:r:E:T:U:jnqvFS",
220 NULL, &bs, NULL, &bpi, NULL, NULL, NULL, NULL,
221 &reserved_percent, NULL, NULL, &label, NULL, NULL, NULL, NULL, NULL, NULL);
222 argv += optind; // argv[0] -- device
224 // check the device is a block device
225 xmove_fd(xopen(argv[0], O_WRONLY), fd);
227 if (!S_ISBLK(st.st_mode) && !(opts & OPT_F))
228 bb_error_msg_and_die("not a block device");
230 // check if it is mounted
231 // N.B. what if we format a file? find_mount_point will return false negative since
232 // it is loop block device which mounted!
233 if (find_mount_point(argv[0], 0))
234 bb_error_msg_and_die("can't format mounted filesystem");
236 // open the device, get size in kbytes
238 kilobytes = xatoull(argv[1]);
239 // seek past end fails on block devices but works on files
240 if (lseek(fd, kilobytes * 1024 - 1, SEEK_SET) != (off_t)-1) {
241 xwrite(fd, "", 1); // file grows if needed
244 // bb_error_msg("warning, block device is smaller");
247 kilobytes = (uoff_t)xlseek(fd, 0, SEEK_END) / 1024;
250 bytes_per_inode = 16384;
251 if (kilobytes < 512*1024)
252 bytes_per_inode = 4096;
253 if (kilobytes < 3*1024)
254 bytes_per_inode = 8192;
256 bytes_per_inode = bpi;
258 // Determine block size
259 // block size is a multiple of 1024
261 if (kilobytes >= 512*1024) // mke2fs 1.41.9 compat
263 if (EXT2_MAX_BLOCK_SIZE > 4096) {
264 // kilobytes >> 22 == size in 4gigabyte chunks.
265 // if size >= 16k gigs, blocksize must be increased.
266 // Try "mke2fs -F image $((16 * 1024*1024*1024))"
267 while ((kilobytes >> 22) >= blocksize)
272 if (blocksize < EXT2_MIN_BLOCK_SIZE
273 || blocksize > EXT2_MAX_BLOCK_SIZE
274 || (blocksize & (blocksize - 1)) // not power of 2
276 bb_error_msg_and_die("blocksize %u is bad", blocksize);
278 if ((int32_t)bytes_per_inode < blocksize)
279 bb_error_msg_and_die("-%c is bad", 'i');
280 // number of bits in one block, i.e. 8*blocksize
281 #define blocks_per_group (8 * blocksize)
282 first_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
283 blocksize_log2 = int_log2(blocksize);
285 // Determine number of blocks
286 kilobytes >>= (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
288 if (nblocks != kilobytes)
289 bb_error_msg_and_die("block count doesn't fit in 32 bits");
290 #define kilobytes kilobytes_unused_after_this
292 // if (blocksize < PAGE_SIZE)
293 // nblocks &= ~((PAGE_SIZE >> blocksize_log2)-1);
294 // Experimentally, standard mke2fs won't work on images smaller than 60k
296 bb_error_msg_and_die("need >= 60 blocks");
298 // How many reserved blocks?
299 if (reserved_percent > 50)
300 bb_error_msg_and_die("-%c is bad", 'm');
301 nreserved = (uint64_t)nblocks * reserved_percent / 100;
303 // N.B. killing e2fsprogs feature! Unused blocks don't account in calculations
304 nblocks_full = nblocks;
306 // If last block group is too small, nblocks may be decreased in order
307 // to discard it, and control returns here to recalculate some
309 // Note: blocksize and bytes_per_inode are never recalculated.
311 // N.B. a block group can have no more than blocks_per_group blocks
312 ngroups = div_roundup(nblocks - first_block, blocks_per_group);
314 group_desc_blocks = div_roundup(ngroups, blocksize / sizeof(*gd));
315 // TODO: reserved blocks must be marked as such in the bitmaps,
316 // or resulting filesystem is corrupt
317 if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) {
319 * From e2fsprogs: Calculate the number of GDT blocks to reserve for online
321 * The absolute maximum number of GDT blocks we can reserve is determined by
322 * the number of block pointers that can fit into a single block.
323 * We set it at 1024x the current filesystem size, or
324 * the upper block count limit (2^32), whichever is lower.
326 uint32_t reserved_group_desc_blocks = 0xFFFFFFFF; // maximum block number
327 if (nblocks < reserved_group_desc_blocks / 1024)
328 reserved_group_desc_blocks = nblocks * 1024;
329 reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks - first_block, blocks_per_group);
330 reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks, blocksize / sizeof(*gd)) - group_desc_blocks;
331 if (reserved_group_desc_blocks > blocksize / sizeof(uint32_t))
332 reserved_group_desc_blocks = blocksize / sizeof(uint32_t);
333 //TODO: STORE_LE(sb->s_reserved_gdt_blocks, reserved_group_desc_blocks);
334 group_desc_blocks += reserved_group_desc_blocks;
338 // N.B. e2fsprogs does as follows!
339 uint32_t overhead, remainder;
340 // ninodes is the max number of inodes in this filesystem
341 uint32_t ninodes = ((uint64_t) nblocks_full * blocksize) / bytes_per_inode;
342 if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
343 ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
344 inodes_per_group = div_roundup(ninodes, ngroups);
345 // minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
346 if (inodes_per_group < 16)
347 inodes_per_group = 16;
348 // a block group can't have more inodes than blocks
349 if (inodes_per_group > blocks_per_group)
350 inodes_per_group = blocks_per_group;
351 // adjust inodes per group so they completely fill the inode table blocks in the descriptor
352 //incompatibility on images >= 0.5GB:
353 //difference in sizeof(*inode) sometimes
354 //results in slightly bigger inodes_per_group here
355 //compared to standard mke2fs:
356 inodes_per_group = (div_roundup(inodes_per_group * sizeof(*inode), blocksize) * blocksize) / sizeof(*inode);
357 // make sure the number of inodes per group is a multiple of 8
358 inodes_per_group &= ~7;
359 inode_table_blocks = div_roundup(inodes_per_group * sizeof(*inode), blocksize);
361 // to be useful, lost+found should occupy at least 2 blocks (but not exceeding 16*1024 bytes),
362 // and at most EXT2_NDIR_BLOCKS. So reserve these blocks right now
363 /* Or e2fsprogs comment verbatim (what does it mean?):
364 * Ensure that lost+found is at least 2 blocks, so we always
365 * test large empty blocks for big-block filesystems. */
366 lost_and_found_blocks = MIN(EXT2_NDIR_BLOCKS, 16 >> (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE));
368 // the last group needs more attention: isn't it too small for possible overhead?
369 overhead = (has_super(ngroups - 1) ? (1/*sb*/ + group_desc_blocks) : 0) + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
370 remainder = (nblocks - first_block) % blocks_per_group;
371 ////can't happen, nblocks >= 60 guarantees this
372 ////if ((1 == ngroups)
374 //// && (remainder < overhead + 1/* "/" */ + lost_and_found_blocks)
376 //// bb_error_msg_and_die("way small device");
379 // Standard mke2fs uses 50. Looks like a bug in our calculation
380 // of "remainder" or "overhead" - we don't match standard mke2fs
381 // when we transition from one group to two groups
382 // (a bit after 8M image size), but it works for two->three groups
383 // transition (at 16M).
384 if (remainder && (remainder < overhead + 50)) {
385 //bb_info_msg("CHOP[%u]", remainder);
386 nblocks -= remainder;
391 if (nblocks_full - nblocks)
392 printf("warning: %u blocks unused\n\n", nblocks_full - nblocks);
394 "Filesystem label=%s\n"
396 "Block size=%u (log=%u)\n"
397 "Fragment size=%u (log=%u)\n"
398 "%u inodes, %u blocks\n"
399 "%u blocks (%u%%) reserved for the super user\n"
400 "First data block=%u\n"
401 "Maximum filesystem blocks=%u\n"
403 "%u blocks per group, %u fragments per group\n"
404 "%u inodes per group"
406 , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
407 , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
408 , inodes_per_group * ngroups, nblocks
409 , nreserved, reserved_percent
411 , group_desc_blocks * (blocksize / sizeof(*gd)) * blocks_per_group
413 , blocks_per_group, blocks_per_group
417 const char *fmt = "\nSuperblock backups stored on blocks:\n"
420 for (i = 1; i < ngroups; i++) {
421 pos += blocks_per_group;
423 printf(fmt, (unsigned)pos);
431 if (ENABLE_FEATURE_CLEAN_UP)
436 // TODO: 3/5 refuse if mounted
437 // TODO: 4/5 compat options
438 // TODO: 1/5 sanity checks
439 // TODO: 0/5 more verbose error messages
440 // TODO: 4/5 bigendianness: recheck, wait for ARM reporters
441 // TODO: 2/5 reserved GDT: how to mark but not allocate?
442 // TODO: 3/5 dir_index?
444 // fill the superblock
446 STORE_LE(sb->s_rev_level, 1); // revision 1 filesystem
447 STORE_LE(sb->s_magic, EXT2_SUPER_MAGIC);
449 //on images > 0.5GB, standard mke2fs uses 256 byte inodes.
450 //we always use 128 byte ones:
451 STORE_LE(sb->s_inode_size, sizeof(*inode));
452 STORE_LE(sb->s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
453 STORE_LE(sb->s_log_block_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
454 STORE_LE(sb->s_log_frag_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
455 // first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then
456 // the first block is 1, otherwise 0
457 STORE_LE(sb->s_first_data_block, first_block);
458 // block and inode bitmaps occupy no more than one block, so maximum number of blocks is
459 STORE_LE(sb->s_blocks_per_group, blocks_per_group);
460 STORE_LE(sb->s_frags_per_group, blocks_per_group);
462 STORE_LE(sb->s_blocks_count, nblocks);
463 // reserve blocks for superuser
464 STORE_LE(sb->s_r_blocks_count, nreserved);
466 STORE_LE(sb->s_inodes_per_group, inodes_per_group);
467 STORE_LE(sb->s_inodes_count, inodes_per_group * ngroups);
468 STORE_LE(sb->s_free_inodes_count, inodes_per_group * ngroups - EXT2_GOOD_OLD_FIRST_INO);
470 timestamp = time(NULL);
471 STORE_LE(sb->s_mkfs_time, timestamp);
472 STORE_LE(sb->s_wtime, timestamp);
473 STORE_LE(sb->s_lastcheck, timestamp);
475 STORE_LE(sb->s_state, 1); // TODO: what's 1?
476 STORE_LE(sb->s_creator_os, EXT2_OS_LINUX);
477 STORE_LE(sb->s_checkinterval, 24*60*60 * 180); // 180 days
478 STORE_LE(sb->s_errors, EXT2_ERRORS_DEFAULT);
479 STORE_LE(sb->s_feature_compat, EXT2_FEATURE_COMPAT_SUPP
480 | (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
481 | (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
483 // e2fsck from 1.41.9 doesn't like EXT2_FEATURE_INCOMPAT_WHITEOUT
484 STORE_LE(sb->s_feature_incompat, EXT2_FEATURE_INCOMPAT_FILETYPE);// | EXT2_FEATURE_INCOMPAT_WHITEOUT;
485 STORE_LE(sb->s_feature_ro_compat, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
486 STORE_LE(sb->s_flags, EXT2_FLAGS_SIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX);
487 generate_uuid(sb->s_uuid);
488 if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
489 STORE_LE(sb->s_def_hash_version, EXT2_HASH_HALF_MD4);
490 generate_uuid((uint8_t *)sb->s_hash_seed);
493 * From e2fsprogs: add "jitter" to the superblock's check interval so that we
494 * don't check all the filesystems at the same time. We use a
495 * kludgy hack of using the UUID to derive a random jitter value.
497 STORE_LE(sb->s_max_mnt_count,
498 EXT2_DFL_MAX_MNT_COUNT
499 + (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));
502 safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
504 // calculate filesystem skeleton structures
505 gd = xzalloc(group_desc_blocks * blocksize);
506 buf = xmalloc(blocksize);
507 sb->s_free_blocks_count = 0;
508 for (i = 0, pos = first_block, n = nblocks - first_block;
510 i++, pos += blocks_per_group, n -= blocks_per_group
512 uint32_t overhead = pos + (has_super(i) ? (1/*sb*/ + group_desc_blocks) : 0);
513 uint32_t free_blocks;
514 // fill group descriptors
515 STORE_LE(gd[i].bg_block_bitmap, overhead + 0);
516 STORE_LE(gd[i].bg_inode_bitmap, overhead + 1);
517 STORE_LE(gd[i].bg_inode_table, overhead + 2);
518 overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
519 gd[i].bg_free_inodes_count = inodes_per_group;
520 //STORE_LE(gd[i].bg_used_dirs_count, 0);
521 // N.B. both "/" and "/lost+found" are within the first block group
522 // "/" occupies 1 block, "/lost+found" occupies lost_and_found_blocks...
524 // ... thus increased overhead for the first block group ...
525 overhead += 1 + lost_and_found_blocks;
526 // ... and 2 used directories
527 STORE_LE(gd[i].bg_used_dirs_count, 2);
528 // well known reserved inodes belong to the first block too
529 gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO;
532 // cache free block count of the group
533 free_blocks = (n < blocks_per_group ? n : blocks_per_group) - overhead;
535 // mark preallocated blocks as allocated
536 //bb_info_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (free_blocks + overhead));
537 allocate(buf, blocksize,
538 // reserve "overhead" blocks
540 // mark unused trailing blocks
541 blocks_per_group - (free_blocks + overhead)
544 PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
545 STORE_LE(gd[i].bg_free_blocks_count, free_blocks);
547 // mark preallocated inodes as allocated
548 allocate(buf, blocksize,
549 // mark reserved inodes
550 inodes_per_group - gd[i].bg_free_inodes_count,
551 // mark unused trailing inodes
552 blocks_per_group - inodes_per_group
555 //PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
556 //but it's right after block bitmap, so we can just:
557 xwrite(fd, buf, blocksize);
558 STORE_LE(gd[i].bg_free_inodes_count, gd[i].bg_free_inodes_count);
560 // count overall free blocks
561 sb->s_free_blocks_count += free_blocks;
563 STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
565 // dump filesystem skeleton structures
566 // printf("Writing superblocks and filesystem accounting information: ");
567 for (i = 0, pos = first_block; i < ngroups; i++, pos += blocks_per_group) {
568 // dump superblock and group descriptors and their backups
570 // N.B. 1024 byte blocks are special
571 PUT(((uint64_t)pos * blocksize) + ((0 == i && 1024 != blocksize) ? 1024 : 0),
573 PUT(((uint64_t)pos * blocksize) + blocksize,
574 gd, group_desc_blocks * blocksize);
579 memset(buf, 0, blocksize);
580 PUT(0, buf, 1024); // N.B. 1024 <= blocksize, so buf[0..1023] contains zeros
582 for (i = 0; i < ngroups; ++i)
583 for (n = 0; n < inode_table_blocks; ++n)
584 PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize,
587 // prepare directory inode
588 inode = (struct ext2_inode *)buf;
589 STORE_LE(inode->i_mode, S_IFDIR | S_IRWXU | S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH);
590 STORE_LE(inode->i_mtime, timestamp);
591 STORE_LE(inode->i_atime, timestamp);
592 STORE_LE(inode->i_ctime, timestamp);
593 STORE_LE(inode->i_size, blocksize);
594 // inode->i_blocks stores the number of 512 byte data blocks
595 // (512, because it goes directly to struct stat without scaling)
596 STORE_LE(inode->i_blocks, blocksize / 512);
598 // dump root dir inode
599 STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this inode
600 STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks);
601 PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * sizeof(*inode),
602 buf, sizeof(*inode));
604 // dump lost+found dir inode
605 STORE_LE(inode->i_links_count, 2); // both "/lost+found" and "/lost+found/." point to this inode
606 STORE_LE(inode->i_size, lost_and_found_blocks * blocksize);
607 STORE_LE(inode->i_blocks, (lost_and_found_blocks * blocksize) / 512);
608 n = FETCH_LE32(inode->i_block[0]) + 1;
609 for (i = 0; i < lost_and_found_blocks; ++i)
610 STORE_LE(inode->i_block[i], i + n); // use next block
611 //bb_info_msg("LAST BLOCK USED[%u]", i + n);
612 PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode),
613 buf, sizeof(*inode));
616 memset(buf, 0, blocksize);
617 dir = (struct ext2_dir *)buf;
619 // dump 2nd+ blocks of "/lost+found"
620 STORE_LE(dir->rec_len1, blocksize); // e2fsck 1.41.4 compat (1.41.9 does not need this)
621 for (i = 1; i < lost_and_found_blocks; ++i)
622 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1+i) * blocksize,
625 // dump 1st block of "/lost+found"
626 STORE_LE(dir->inode1, EXT2_GOOD_OLD_FIRST_INO);
627 STORE_LE(dir->rec_len1, 12);
628 STORE_LE(dir->name_len1, 1);
629 STORE_LE(dir->file_type1, EXT2_FT_DIR);
631 STORE_LE(dir->inode2, EXT2_ROOT_INO);
632 STORE_LE(dir->rec_len2, blocksize - 12);
633 STORE_LE(dir->name_len2, 2);
634 STORE_LE(dir->file_type2, EXT2_FT_DIR);
635 dir->name2[0] = '.'; dir->name2[1] = '.';
636 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1) * blocksize, buf, blocksize);
638 // dump root dir block
639 STORE_LE(dir->inode1, EXT2_ROOT_INO);
640 STORE_LE(dir->rec_len2, 12);
641 STORE_LE(dir->inode3, EXT2_GOOD_OLD_FIRST_INO);
642 STORE_LE(dir->rec_len3, blocksize - 12 - 12);
643 STORE_LE(dir->name_len3, 10);
644 STORE_LE(dir->file_type3, EXT2_FT_DIR);
645 strcpy(dir->name3, "lost+found");
646 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 0) * blocksize, buf, blocksize);
649 if (ENABLE_FEATURE_CLEAN_UP) {