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]);
240 kilobytes = (uoff_t)xlseek(fd, 0, SEEK_END) / 1024;
243 bytes_per_inode = 16384;
244 if (kilobytes < 512*1024)
245 bytes_per_inode = 4096;
246 if (kilobytes < 3*1024)
247 bytes_per_inode = 8192;
249 bytes_per_inode = bpi;
251 // Determine block size
252 // block size is a multiple of 1024
254 if (kilobytes >= 512*1024) // mke2fs 1.41.9 compat
256 if (EXT2_MAX_BLOCK_SIZE > 4096) {
257 // kilobytes >> 22 == size in 4gigabyte chunks.
258 // if size >= 16k gigs, blocksize must be increased.
259 // Try "mke2fs -F image $((16 * 1024*1024*1024))"
260 while ((kilobytes >> 22) >= blocksize)
265 if (blocksize < EXT2_MIN_BLOCK_SIZE
266 || blocksize > EXT2_MAX_BLOCK_SIZE
267 || (blocksize & (blocksize - 1)) // not power of 2
269 bb_error_msg_and_die("blocksize %u is bad", blocksize);
271 if ((int32_t)bytes_per_inode < blocksize)
272 bb_error_msg_and_die("-%c is bad", 'i');
273 // number of bits in one block, i.e. 8*blocksize
274 #define blocks_per_group (8 * blocksize)
275 first_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
276 blocksize_log2 = int_log2(blocksize);
278 // Determine number of blocks
279 kilobytes >>= (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
281 if (nblocks != kilobytes)
282 bb_error_msg_and_die("block count doesn't fit in 32 bits");
283 #define kilobytes kilobytes_unused_after_this
285 // if (blocksize < PAGE_SIZE)
286 // nblocks &= ~((PAGE_SIZE >> blocksize_log2)-1);
287 // Experimentally, standard mke2fs won't work on images smaller than 60k
289 bb_error_msg_and_die("need >= 60 blocks");
291 // How many reserved blocks?
292 if (reserved_percent > 50)
293 bb_error_msg_and_die("-%c is bad", 'm');
294 nreserved = (uint64_t)nblocks * reserved_percent / 100;
296 // N.B. killing e2fsprogs feature! Unused blocks don't account in calculations
297 nblocks_full = nblocks;
299 // If last block group is too small, nblocks may be decreased in order
300 // to discard it, and control returns here to recalculate some
302 // Note: blocksize and bytes_per_inode are never recalculated.
304 // N.B. a block group can have no more than blocks_per_group blocks
305 ngroups = div_roundup(nblocks - first_block, blocks_per_group);
307 group_desc_blocks = div_roundup(ngroups, blocksize / sizeof(*gd));
308 // TODO: reserved blocks must be marked as such in the bitmaps,
309 // or resulting filesystem is corrupt
310 if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) {
312 * From e2fsprogs: Calculate the number of GDT blocks to reserve for online
314 * The absolute maximum number of GDT blocks we can reserve is determined by
315 * the number of block pointers that can fit into a single block.
316 * We set it at 1024x the current filesystem size, or
317 * the upper block count limit (2^32), whichever is lower.
319 uint32_t reserved_group_desc_blocks = 0xFFFFFFFF; // maximum block number
320 if (nblocks < reserved_group_desc_blocks / 1024)
321 reserved_group_desc_blocks = nblocks * 1024;
322 reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks - first_block, blocks_per_group);
323 reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks, blocksize / sizeof(*gd)) - group_desc_blocks;
324 if (reserved_group_desc_blocks > blocksize / sizeof(uint32_t))
325 reserved_group_desc_blocks = blocksize / sizeof(uint32_t);
326 //TODO: STORE_LE(sb->s_reserved_gdt_blocks, reserved_group_desc_blocks);
327 group_desc_blocks += reserved_group_desc_blocks;
331 // N.B. e2fsprogs does as follows!
332 uint32_t overhead, remainder;
333 // ninodes is the max number of inodes in this filesystem
334 uint32_t ninodes = ((uint64_t) nblocks_full * blocksize) / bytes_per_inode;
335 if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
336 ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
337 inodes_per_group = div_roundup(ninodes, ngroups);
338 // minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
339 if (inodes_per_group < 16)
340 inodes_per_group = 16;
341 // a block group can't have more inodes than blocks
342 if (inodes_per_group > blocks_per_group)
343 inodes_per_group = blocks_per_group;
344 // adjust inodes per group so they completely fill the inode table blocks in the descriptor
345 //incompatibility on images >= 0.5GB:
346 //difference in sizeof(*inode) sometimes
347 //results in slightly bigger inodes_per_group here
348 //compared to standard mke2fs:
349 inodes_per_group = (div_roundup(inodes_per_group * sizeof(*inode), blocksize) * blocksize) / sizeof(*inode);
350 // make sure the number of inodes per group is a multiple of 8
351 inodes_per_group &= ~7;
352 inode_table_blocks = div_roundup(inodes_per_group * sizeof(*inode), blocksize);
354 // to be useful, lost+found should occupy at least 2 blocks (but not exceeding 16*1024 bytes),
355 // and at most EXT2_NDIR_BLOCKS. So reserve these blocks right now
356 /* Or e2fsprogs comment verbatim (what does it mean?):
357 * Ensure that lost+found is at least 2 blocks, so we always
358 * test large empty blocks for big-block filesystems. */
359 lost_and_found_blocks = MIN(EXT2_NDIR_BLOCKS, 16 >> (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE));
361 // the last group needs more attention: isn't it too small for possible overhead?
362 overhead = (has_super(ngroups - 1) ? (1/*sb*/ + group_desc_blocks) : 0) + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
363 remainder = (nblocks - first_block) % blocks_per_group;
364 ////can't happen, nblocks >= 60 guarantees this
365 ////if ((1 == ngroups)
367 //// && (remainder < overhead + 1/* "/" */ + lost_and_found_blocks)
369 //// bb_error_msg_and_die("way small device");
372 // Standard mke2fs uses 50. Looks like a bug in our calculation
373 // of "remainder" or "overhead" - we don't match standard mke2fs
374 // when we transition from one group to two groups
375 // (a bit after 8M image size), but it works for two->three groups
376 // transition (at 16M).
377 if (remainder && (remainder < overhead + 50)) {
378 //bb_info_msg("CHOP[%u]", remainder);
379 nblocks -= remainder;
384 if (nblocks_full - nblocks)
385 printf("warning: %u blocks unused\n\n", nblocks_full - nblocks);
387 "Filesystem label=%s\n"
389 "Block size=%u (log=%u)\n"
390 "Fragment size=%u (log=%u)\n"
391 "%u inodes, %u blocks\n"
392 "%u blocks (%u%%) reserved for the super user\n"
393 "First data block=%u\n"
394 "Maximum filesystem blocks=%u\n"
396 "%u blocks per group, %u fragments per group\n"
397 "%u inodes per group"
399 , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
400 , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
401 , inodes_per_group * ngroups, nblocks
402 , nreserved, reserved_percent
404 , group_desc_blocks * (blocksize / sizeof(*gd)) * blocks_per_group
406 , blocks_per_group, blocks_per_group
410 const char *fmt = "\nSuperblock backups stored on blocks:\n"
413 for (i = 1; i < ngroups; i++) {
414 pos += blocks_per_group;
416 printf(fmt, (unsigned)pos);
424 if (ENABLE_FEATURE_CLEAN_UP)
429 // TODO: 3/5 refuse if mounted
430 // TODO: 4/5 compat options
431 // TODO: 1/5 sanity checks
432 // TODO: 0/5 more verbose error messages
433 // TODO: 4/5 bigendianness: recheck, wait for ARM reporters
434 // TODO: 2/5 reserved GDT: how to mark but not allocate?
435 // TODO: 3/5 dir_index?
437 // fill the superblock
439 STORE_LE(sb->s_rev_level, 1); // revision 1 filesystem
440 STORE_LE(sb->s_magic, EXT2_SUPER_MAGIC);
442 //on images > 0.5GB, standard mke2fs uses 256 byte inodes.
443 //we always use 128 byte ones:
444 STORE_LE(sb->s_inode_size, sizeof(*inode));
445 STORE_LE(sb->s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
446 STORE_LE(sb->s_log_block_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
447 STORE_LE(sb->s_log_frag_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
448 // first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then
449 // the first block is 1, otherwise 0
450 STORE_LE(sb->s_first_data_block, first_block);
451 // block and inode bitmaps occupy no more than one block, so maximum number of blocks is
452 STORE_LE(sb->s_blocks_per_group, blocks_per_group);
453 STORE_LE(sb->s_frags_per_group, blocks_per_group);
455 STORE_LE(sb->s_blocks_count, nblocks);
456 // reserve blocks for superuser
457 STORE_LE(sb->s_r_blocks_count, nreserved);
459 STORE_LE(sb->s_inodes_per_group, inodes_per_group);
460 STORE_LE(sb->s_inodes_count, inodes_per_group * ngroups);
461 STORE_LE(sb->s_free_inodes_count, inodes_per_group * ngroups - EXT2_GOOD_OLD_FIRST_INO);
463 timestamp = time(NULL);
464 STORE_LE(sb->s_mkfs_time, timestamp);
465 STORE_LE(sb->s_wtime, timestamp);
466 STORE_LE(sb->s_lastcheck, timestamp);
468 STORE_LE(sb->s_state, 1); // TODO: what's 1?
469 STORE_LE(sb->s_creator_os, EXT2_OS_LINUX);
470 STORE_LE(sb->s_checkinterval, 24*60*60 * 180); // 180 days
471 STORE_LE(sb->s_errors, EXT2_ERRORS_DEFAULT);
472 STORE_LE(sb->s_feature_compat, EXT2_FEATURE_COMPAT_SUPP
473 | (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
474 | (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
476 // e2fsck from 1.41.9 doesn't like EXT2_FEATURE_INCOMPAT_WHITEOUT
477 STORE_LE(sb->s_feature_incompat, EXT2_FEATURE_INCOMPAT_FILETYPE);// | EXT2_FEATURE_INCOMPAT_WHITEOUT;
478 STORE_LE(sb->s_feature_ro_compat, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
479 STORE_LE(sb->s_flags, EXT2_FLAGS_SIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX);
480 generate_uuid(sb->s_uuid);
481 if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
482 STORE_LE(sb->s_def_hash_version, EXT2_HASH_HALF_MD4);
483 generate_uuid((uint8_t *)sb->s_hash_seed);
486 * From e2fsprogs: add "jitter" to the superblock's check interval so that we
487 * don't check all the filesystems at the same time. We use a
488 * kludgy hack of using the UUID to derive a random jitter value.
490 STORE_LE(sb->s_max_mnt_count,
491 EXT2_DFL_MAX_MNT_COUNT
492 + (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));
495 safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
497 // calculate filesystem skeleton structures
498 gd = xzalloc(group_desc_blocks * blocksize);
499 buf = xmalloc(blocksize);
500 sb->s_free_blocks_count = 0;
501 for (i = 0, pos = first_block, n = nblocks - first_block;
503 i++, pos += blocks_per_group, n -= blocks_per_group
505 uint32_t overhead = pos + (has_super(i) ? (1/*sb*/ + group_desc_blocks) : 0);
506 uint32_t free_blocks;
507 // fill group descriptors
508 STORE_LE(gd[i].bg_block_bitmap, overhead + 0);
509 STORE_LE(gd[i].bg_inode_bitmap, overhead + 1);
510 STORE_LE(gd[i].bg_inode_table, overhead + 2);
511 overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
512 gd[i].bg_free_inodes_count = inodes_per_group;
513 //STORE_LE(gd[i].bg_used_dirs_count, 0);
514 // N.B. both "/" and "/lost+found" are within the first block group
515 // "/" occupies 1 block, "/lost+found" occupies lost_and_found_blocks...
517 // ... thus increased overhead for the first block group ...
518 overhead += 1 + lost_and_found_blocks;
519 // ... and 2 used directories
520 STORE_LE(gd[i].bg_used_dirs_count, 2);
521 // well known reserved inodes belong to the first block too
522 gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO;
525 // cache free block count of the group
526 free_blocks = (n < blocks_per_group ? n : blocks_per_group) - overhead;
528 // mark preallocated blocks as allocated
529 //bb_info_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (free_blocks + overhead));
530 allocate(buf, blocksize,
531 // reserve "overhead" blocks
533 // mark unused trailing blocks
534 blocks_per_group - (free_blocks + overhead)
537 PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
538 STORE_LE(gd[i].bg_free_blocks_count, free_blocks);
540 // mark preallocated inodes as allocated
541 allocate(buf, blocksize,
542 // mark reserved inodes
543 inodes_per_group - gd[i].bg_free_inodes_count,
544 // mark unused trailing inodes
545 blocks_per_group - inodes_per_group
548 //PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
549 //but it's right after block bitmap, so we can just:
550 xwrite(fd, buf, blocksize);
551 STORE_LE(gd[i].bg_free_inodes_count, gd[i].bg_free_inodes_count);
553 // count overall free blocks
554 sb->s_free_blocks_count += free_blocks;
556 STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
558 // dump filesystem skeleton structures
559 // printf("Writing superblocks and filesystem accounting information: ");
560 for (i = 0, pos = first_block; i < ngroups; i++, pos += blocks_per_group) {
561 // dump superblock and group descriptors and their backups
563 // N.B. 1024 byte blocks are special
564 PUT(((uint64_t)pos * blocksize) + ((0 == i && 1024 != blocksize) ? 1024 : 0),
566 PUT(((uint64_t)pos * blocksize) + blocksize,
567 gd, group_desc_blocks * blocksize);
572 memset(buf, 0, blocksize);
573 PUT(0, buf, 1024); // N.B. 1024 <= blocksize, so buf[0..1023] contains zeros
575 for (i = 0; i < ngroups; ++i)
576 for (n = 0; n < inode_table_blocks; ++n)
577 PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize,
580 // prepare directory inode
581 inode = (struct ext2_inode *)buf;
582 STORE_LE(inode->i_mode, S_IFDIR | S_IRWXU | S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH);
583 STORE_LE(inode->i_mtime, timestamp);
584 STORE_LE(inode->i_atime, timestamp);
585 STORE_LE(inode->i_ctime, timestamp);
586 STORE_LE(inode->i_size, blocksize);
587 // inode->i_blocks stores the number of 512 byte data blocks
588 // (512, because it goes directly to struct stat without scaling)
589 STORE_LE(inode->i_blocks, blocksize / 512);
591 // dump root dir inode
592 STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this inode
593 STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks);
594 PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * sizeof(*inode),
595 buf, sizeof(*inode));
597 // dump lost+found dir inode
598 STORE_LE(inode->i_links_count, 2); // both "/lost+found" and "/lost+found/." point to this inode
599 STORE_LE(inode->i_size, lost_and_found_blocks * blocksize);
600 STORE_LE(inode->i_blocks, (lost_and_found_blocks * blocksize) / 512);
601 n = FETCH_LE32(inode->i_block[0]) + 1;
602 for (i = 0; i < lost_and_found_blocks; ++i)
603 STORE_LE(inode->i_block[i], i + n); // use next block
604 //bb_info_msg("LAST BLOCK USED[%u]", i + n);
605 PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode),
606 buf, sizeof(*inode));
609 memset(buf, 0, blocksize);
610 dir = (struct ext2_dir *)buf;
612 // dump 2nd+ blocks of "/lost+found"
613 STORE_LE(dir->rec_len1, blocksize); // e2fsck 1.41.4 compat
614 for (i = 1; i < lost_and_found_blocks; ++i)
615 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1+i) * blocksize,
618 // dump 1st block of "/lost+found"
619 STORE_LE(dir->inode1, EXT2_GOOD_OLD_FIRST_INO);
620 STORE_LE(dir->rec_len1, 12);
621 STORE_LE(dir->name_len1, 1);
622 STORE_LE(dir->file_type1, EXT2_FT_DIR);
624 STORE_LE(dir->inode2, EXT2_ROOT_INO);
625 STORE_LE(dir->rec_len2, blocksize - 12);
626 STORE_LE(dir->name_len2, 2);
627 STORE_LE(dir->file_type2, EXT2_FT_DIR);
628 dir->name2[0] = '.'; dir->name2[1] = '.';
629 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1) * blocksize, buf, blocksize);
631 // dump root dir block
632 STORE_LE(dir->inode1, EXT2_ROOT_INO);
633 STORE_LE(dir->rec_len2, 12);
634 STORE_LE(dir->inode3, EXT2_GOOD_OLD_FIRST_INO);
635 STORE_LE(dir->rec_len3, blocksize - 12 - 12);
636 STORE_LE(dir->name_len3, 10);
637 STORE_LE(dir->file_type3, EXT2_FT_DIR);
638 strcpy(dir->name3, "lost+found");
639 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 0) * blocksize, buf, blocksize);
642 if (ENABLE_FEATURE_CLEAN_UP) {