source: MondoRescue/branches/3.2/mindi-busybox/util-linux/mkfs_ext2.c@ 3232

Last change on this file since 3232 was 3232, checked in by Bruno Cornec, 10 years ago
  • Update mindi-busybox to 1.21.1
  • Property svn:eol-style set to native
File size: 25.1 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * mkfs_ext2: utility to create EXT2 filesystem
4 * inspired by genext2fs
5 *
6 * Busybox'ed (2009) by Vladimir Dronnikov <dronnikov@gmail.com>
7 *
8 * Licensed under GPLv2, see file LICENSE in this source tree.
9 */
10
11//usage:#define mkfs_ext2_trivial_usage
12//usage: "[-Fn] "
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" */
48
49#include "libbb.h"
50#include <linux/fs.h>
51#include "bb_e2fs_defs.h"
52
53#define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
54#define ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX 1
55
56#define EXT2_HASH_HALF_MD4 1
57#define EXT2_FLAGS_SIGNED_HASH 0x0001
58#define EXT2_FLAGS_UNSIGNED_HASH 0x0002
59
60// storage helpers
61char BUG_wrong_field_size(void);
62#define STORE_LE(field, value) \
63do { \
64 if (sizeof(field) == 4) \
65 field = SWAP_LE32(value); \
66 else if (sizeof(field) == 2) \
67 field = SWAP_LE16(value); \
68 else if (sizeof(field) == 1) \
69 field = (value); \
70 else \
71 BUG_wrong_field_size(); \
72} while (0)
73
74#define FETCH_LE32(field) \
75 (sizeof(field) == 4 ? SWAP_LE32(field) : BUG_wrong_field_size())
76
77// All fields are little-endian
78struct ext2_dir {
79 uint32_t inode1;
80 uint16_t rec_len1;
81 uint8_t name_len1;
82 uint8_t file_type1;
83 char name1[4];
84 uint32_t inode2;
85 uint16_t rec_len2;
86 uint8_t name_len2;
87 uint8_t file_type2;
88 char name2[4];
89 uint32_t inode3;
90 uint16_t rec_len3;
91 uint8_t name_len3;
92 uint8_t file_type3;
93 char name3[12];
94};
95
96static unsigned int_log2(unsigned arg)
97{
98 unsigned r = 0;
99 while ((arg >>= 1) != 0)
100 r++;
101 return r;
102}
103
104// taken from mkfs_minix.c. libbb candidate?
105// "uint32_t size", since we never use it for anything >32 bits
106static uint32_t div_roundup(uint32_t size, uint32_t n)
107{
108 // Overflow-resistant
109 uint32_t res = size / n;
110 if (res * n != size)
111 res++;
112 return res;
113}
114
115static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32_t end)
116{
117 uint32_t i;
118
119//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)));
120 memset(bitmap, 0, blocksize);
121 i = start / 8;
122 memset(bitmap, 0xFF, i);
123 bitmap[i] = (1 << (start & 7)) - 1; //0..7 => 00000000..01111111
124 i = end / 8;
125 bitmap[blocksize - i - 1] |= 0x7F00 >> (end & 7); //0..7 => 00000000..11111110
126 memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here!
127}
128
129static uint32_t has_super(uint32_t x)
130{
131 // 0, 1 and powers of 3, 5, 7 up to 2^32 limit
132 static const uint32_t supers[] = {
133 0, 1, 3, 5, 7, 9, 25, 27, 49, 81, 125, 243, 343, 625, 729,
134 2187, 2401, 3125, 6561, 15625, 16807, 19683, 59049, 78125,
135 117649, 177147, 390625, 531441, 823543, 1594323, 1953125,
136 4782969, 5764801, 9765625, 14348907, 40353607, 43046721,
137 48828125, 129140163, 244140625, 282475249, 387420489,
138 1162261467, 1220703125, 1977326743, 3486784401/* >2^31 */,
139 };
140 const uint32_t *sp = supers + ARRAY_SIZE(supers);
141 while (1) {
142 sp--;
143 if (x == *sp)
144 return 1;
145 if (x > *sp)
146 return 0;
147 }
148}
149
150#define fd 3 /* predefined output descriptor */
151
152static void PUT(uint64_t off, void *buf, uint32_t size)
153{
154// bb_info_msg("PUT[%llu]:[%u]", off, size);
155 xlseek(fd, off, SEEK_SET);
156 xwrite(fd, buf, size);
157}
158
159// 128 and 256-byte inodes:
160// 128-byte inode is described by struct ext2_inode.
161// 256-byte one just has these fields appended:
162// __u16 i_extra_isize;
163// __u16 i_pad1;
164// __u32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */
165// __u32 i_mtime_extra; /* extra Modification time (nsec << 2 | epoch) */
166// __u32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */
167// __u32 i_crtime; /* File creation time */
168// __u32 i_crtime_extra; /* extra File creation time (nsec << 2 | epoch)*/
169// __u32 i_version_hi; /* high 32 bits for 64-bit version */
170// the rest is padding.
171//
172// linux/ext2_fs.h has "#define i_size_high i_dir_acl" which suggests that even
173// 128-byte inode is capable of describing large files (i_dir_acl is meaningful
174// only for directories, which never need i_size_high).
175//
176// Standard mke2fs creates a filesystem with 256-byte inodes if it is
177// bigger than 0.5GB.
178
179// Standard mke2fs 1.41.9:
180// Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size]
181// [-i bytes-per-inode] [-I inode-size] [-J journal-options]
182// [-G meta group size] [-N number-of-inodes]
183// [-m reserved-blocks-percentage] [-o creator-os]
184// [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
185// [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
186// [-T fs-type] [-U UUID] [-jnqvFSV] device [blocks-count]
187//
188// Options not commented below are taken but silently ignored:
189enum {
190 OPT_c = 1 << 0,
191 OPT_l = 1 << 1,
192 OPT_b = 1 << 2, // block size, in bytes
193 OPT_f = 1 << 3,
194 OPT_i = 1 << 4, // bytes per inode
195 OPT_I = 1 << 5, // custom inode size, in bytes
196 OPT_J = 1 << 6,
197 OPT_G = 1 << 7,
198 OPT_N = 1 << 8,
199 OPT_m = 1 << 9, // percentage of blocks reserved for superuser
200 OPT_o = 1 << 10,
201 OPT_g = 1 << 11,
202 OPT_L = 1 << 12, // label
203 OPT_M = 1 << 13,
204 OPT_O = 1 << 14,
205 OPT_r = 1 << 15,
206 OPT_E = 1 << 16,
207 OPT_T = 1 << 17,
208 OPT_U = 1 << 18,
209 OPT_j = 1 << 19,
210 OPT_n = 1 << 20, // dry run: do not write anything
211 OPT_q = 1 << 21,
212 OPT_v = 1 << 22,
213 OPT_F = 1 << 23,
214 OPT_S = 1 << 24,
215 //OPT_V = 1 << 25, // -V version. bbox applets don't support that
216};
217
218int mkfs_ext2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
219int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
220{
221 unsigned i, pos, n;
222 unsigned bs, bpi;
223 unsigned blocksize, blocksize_log2;
224 unsigned inodesize, user_inodesize;
225 unsigned reserved_percent = 5;
226 unsigned long long kilobytes;
227 uint32_t nblocks, nblocks_full;
228 uint32_t nreserved;
229 uint32_t ngroups;
230 uint32_t bytes_per_inode;
231 uint32_t first_block;
232 uint32_t inodes_per_group;
233 uint32_t group_desc_blocks;
234 uint32_t inode_table_blocks;
235 uint32_t lost_and_found_blocks;
236 time_t timestamp;
237 const char *label = "";
238 struct stat st;
239 struct ext2_super_block *sb; // superblock
240 struct ext2_group_desc *gd; // group descriptors
241 struct ext2_inode *inode;
242 struct ext2_dir *dir;
243 uint8_t *buf;
244
245 // using global "option_mask32" instead of local "opts":
246 // we are register starved here
247 opt_complementary = "-1:b+:i+:I+:m+";
248 /*opts =*/ getopt32(argv, "cl:b:f:i:I:J:G:N:m:o:g:L:M:O:r:E:T:U:jnqvFS",
249 /*lbfi:*/ NULL, &bs, NULL, &bpi,
250 /*IJGN:*/ &user_inodesize, NULL, NULL, NULL,
251 /*mogL:*/ &reserved_percent, NULL, NULL, &label,
252 /*MOrE:*/ NULL, NULL, NULL, NULL,
253 /*TU:*/ NULL, NULL);
254 argv += optind; // argv[0] -- device
255
256 // open the device, check the device is a block device
257 xmove_fd(xopen(argv[0], O_WRONLY), fd);
258 xfstat(fd, &st, argv[0]);
259 if (!S_ISBLK(st.st_mode) && !(option_mask32 & OPT_F))
260 bb_error_msg_and_die("%s: not a block device", argv[0]);
261
262 // check if it is mounted
263 // N.B. what if we format a file? find_mount_point will return false negative since
264 // it is loop block device which is mounted!
265 if (find_mount_point(argv[0], 0))
266 bb_error_msg_and_die("can't format mounted filesystem");
267
268 // get size in kbytes
269 kilobytes = get_volume_size_in_bytes(fd, argv[1], 1024, /*extend:*/ !(option_mask32 & OPT_n)) / 1024;
270
271 bytes_per_inode = 16384;
272 if (kilobytes < 512*1024)
273 bytes_per_inode = 4096;
274 if (kilobytes < 3*1024)
275 bytes_per_inode = 8192;
276 if (option_mask32 & OPT_i)
277 bytes_per_inode = bpi;
278
279 // Determine block size and inode size
280 // block size is a multiple of 1024
281 // inode size is a multiple of 128
282 blocksize = 1024;
283 inodesize = sizeof(struct ext2_inode); // 128
284 if (kilobytes >= 512*1024) { // mke2fs 1.41.9 compat
285 blocksize = 4096;
286 inodesize = 256;
287 }
288 if (EXT2_MAX_BLOCK_SIZE > 4096) {
289 // kilobytes >> 22 == size in 4gigabyte chunks.
290 // if size >= 16k gigs, blocksize must be increased.
291 // Try "mke2fs -F image $((16 * 1024*1024*1024))"
292 while ((kilobytes >> 22) >= blocksize)
293 blocksize *= 2;
294 }
295 if (option_mask32 & OPT_b)
296 blocksize = bs;
297 if (blocksize < EXT2_MIN_BLOCK_SIZE
298 || blocksize > EXT2_MAX_BLOCK_SIZE
299 || (blocksize & (blocksize - 1)) // not power of 2
300 ) {
301 bb_error_msg_and_die("blocksize %u is bad", blocksize);
302 }
303 // Do we have custom inode size?
304 if (option_mask32 & OPT_I) {
305 if (user_inodesize < sizeof(*inode)
306 || user_inodesize > blocksize
307 || (user_inodesize & (user_inodesize - 1)) // not power of 2
308 ) {
309 bb_error_msg("-%c is bad", 'I');
310 } else {
311 inodesize = user_inodesize;
312 }
313 }
314
315 if ((int32_t)bytes_per_inode < blocksize)
316 bb_error_msg_and_die("-%c is bad", 'i');
317 // number of bits in one block, i.e. 8*blocksize
318#define blocks_per_group (8 * blocksize)
319 first_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
320 blocksize_log2 = int_log2(blocksize);
321
322 // Determine number of blocks
323 kilobytes >>= (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
324 nblocks = kilobytes;
325 if (nblocks != kilobytes)
326 bb_error_msg_and_die("block count doesn't fit in 32 bits");
327#define kilobytes kilobytes_unused_after_this
328 // Experimentally, standard mke2fs won't work on images smaller than 60k
329 if (nblocks < 60)
330 bb_error_msg_and_die("need >= 60 blocks");
331
332 // How many reserved blocks?
333 if (reserved_percent > 50)
334 bb_error_msg_and_die("-%c is bad", 'm');
335 nreserved = (uint64_t)nblocks * reserved_percent / 100;
336
337 // N.B. killing e2fsprogs feature! Unused blocks don't account in calculations
338 nblocks_full = nblocks;
339
340 // If last block group is too small, nblocks may be decreased in order
341 // to discard it, and control returns here to recalculate some
342 // parameters.
343 // Note: blocksize and bytes_per_inode are never recalculated.
344 retry:
345 // N.B. a block group can have no more than blocks_per_group blocks
346 ngroups = div_roundup(nblocks - first_block, blocks_per_group);
347
348 group_desc_blocks = div_roundup(ngroups, blocksize / sizeof(*gd));
349 // TODO: reserved blocks must be marked as such in the bitmaps,
350 // or resulting filesystem is corrupt
351 if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) {
352 /*
353 * From e2fsprogs: Calculate the number of GDT blocks to reserve for online
354 * filesystem growth.
355 * The absolute maximum number of GDT blocks we can reserve is determined by
356 * the number of block pointers that can fit into a single block.
357 * We set it at 1024x the current filesystem size, or
358 * the upper block count limit (2^32), whichever is lower.
359 */
360 uint32_t reserved_group_desc_blocks = 0xFFFFFFFF; // maximum block number
361 if (nblocks < reserved_group_desc_blocks / 1024)
362 reserved_group_desc_blocks = nblocks * 1024;
363 reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks - first_block, blocks_per_group);
364 reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks, blocksize / sizeof(*gd)) - group_desc_blocks;
365 if (reserved_group_desc_blocks > blocksize / sizeof(uint32_t))
366 reserved_group_desc_blocks = blocksize / sizeof(uint32_t);
367 //TODO: STORE_LE(sb->s_reserved_gdt_blocks, reserved_group_desc_blocks);
368 group_desc_blocks += reserved_group_desc_blocks;
369 }
370
371 {
372 // N.B. e2fsprogs does as follows!
373 uint32_t overhead, remainder;
374 // ninodes is the max number of inodes in this filesystem
375 uint32_t ninodes = ((uint64_t) nblocks_full * blocksize) / bytes_per_inode;
376 if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
377 ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
378 inodes_per_group = div_roundup(ninodes, ngroups);
379 // minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
380 if (inodes_per_group < 16)
381 inodes_per_group = 16;
382 // a block group can't have more inodes than blocks
383 if (inodes_per_group > blocks_per_group)
384 inodes_per_group = blocks_per_group;
385 // adjust inodes per group so they completely fill the inode table blocks in the descriptor
386 inodes_per_group = (div_roundup(inodes_per_group * inodesize, blocksize) * blocksize) / inodesize;
387 // make sure the number of inodes per group is a multiple of 8
388 inodes_per_group &= ~7;
389 inode_table_blocks = div_roundup(inodes_per_group * inodesize, blocksize);
390
391 // to be useful, lost+found should occupy at least 2 blocks (but not exceeding 16*1024 bytes),
392 // and at most EXT2_NDIR_BLOCKS. So reserve these blocks right now
393 /* Or e2fsprogs comment verbatim (what does it mean?):
394 * Ensure that lost+found is at least 2 blocks, so we always
395 * test large empty blocks for big-block filesystems. */
396 lost_and_found_blocks = MIN(EXT2_NDIR_BLOCKS, 16 >> (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE));
397
398 // the last group needs more attention: isn't it too small for possible overhead?
399 overhead = (has_super(ngroups - 1) ? (1/*sb*/ + group_desc_blocks) : 0) + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
400 remainder = (nblocks - first_block) % blocks_per_group;
401 ////can't happen, nblocks >= 60 guarantees this
402 ////if ((1 == ngroups)
403 //// && remainder
404 //// && (remainder < overhead + 1/* "/" */ + lost_and_found_blocks)
405 ////) {
406 //// bb_error_msg_and_die("way small device");
407 ////}
408
409 // Standard mke2fs uses 50. Looks like a bug in our calculation
410 // of "remainder" or "overhead" - we don't match standard mke2fs
411 // when we transition from one group to two groups
412 // (a bit after 8M image size), but it works for two->three groups
413 // transition (at 16M).
414 if (remainder && (remainder < overhead + 50)) {
415//bb_info_msg("CHOP[%u]", remainder);
416 nblocks -= remainder;
417 goto retry;
418 }
419 }
420
421 if (nblocks_full - nblocks)
422 printf("warning: %u blocks unused\n\n", nblocks_full - nblocks);
423 printf(
424 "Filesystem label=%s\n"
425 "OS type: Linux\n"
426 "Block size=%u (log=%u)\n"
427 "Fragment size=%u (log=%u)\n"
428 "%u inodes, %u blocks\n"
429 "%u blocks (%u%%) reserved for the super user\n"
430 "First data block=%u\n"
431 "Maximum filesystem blocks=%u\n"
432 "%u block groups\n"
433 "%u blocks per group, %u fragments per group\n"
434 "%u inodes per group"
435 , label
436 , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
437 , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
438 , inodes_per_group * ngroups, nblocks
439 , nreserved, reserved_percent
440 , first_block
441 , group_desc_blocks * (blocksize / (unsigned)sizeof(*gd)) * blocks_per_group
442 , ngroups
443 , blocks_per_group, blocks_per_group
444 , inodes_per_group
445 );
446 {
447 const char *fmt = "\nSuperblock backups stored on blocks:\n"
448 "\t%u";
449 pos = first_block;
450 for (i = 1; i < ngroups; i++) {
451 pos += blocks_per_group;
452 if (has_super(i)) {
453 printf(fmt, (unsigned)pos);
454 fmt = ", %u";
455 }
456 }
457 }
458 bb_putchar('\n');
459
460 if (option_mask32 & OPT_n) {
461 if (ENABLE_FEATURE_CLEAN_UP)
462 close(fd);
463 return EXIT_SUCCESS;
464 }
465
466 // TODO: 3/5 refuse if mounted
467 // TODO: 4/5 compat options
468 // TODO: 1/5 sanity checks
469 // TODO: 0/5 more verbose error messages
470 // TODO: 4/5 bigendianness: recheck, wait for ARM reporters
471 // TODO: 2/5 reserved GDT: how to mark but not allocate?
472 // TODO: 3/5 dir_index?
473
474 // fill the superblock
475 sb = xzalloc(1024);
476 STORE_LE(sb->s_rev_level, EXT2_DYNAMIC_REV); // revision 1 filesystem
477 STORE_LE(sb->s_magic, EXT2_SUPER_MAGIC);
478 STORE_LE(sb->s_inode_size, inodesize);
479 // set "Required extra isize" and "Desired extra isize" fields to 28
480 if (inodesize != sizeof(*inode)) {
481 STORE_LE(sb->s_min_extra_isize, 0x001c);
482 STORE_LE(sb->s_want_extra_isize, 0x001c);
483 }
484 STORE_LE(sb->s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
485 STORE_LE(sb->s_log_block_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
486 STORE_LE(sb->s_log_frag_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
487 // first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then
488 // the first block is 1, otherwise 0
489 STORE_LE(sb->s_first_data_block, first_block);
490 // block and inode bitmaps occupy no more than one block, so maximum number of blocks is
491 STORE_LE(sb->s_blocks_per_group, blocks_per_group);
492 STORE_LE(sb->s_frags_per_group, blocks_per_group);
493 // blocks
494 STORE_LE(sb->s_blocks_count, nblocks);
495 // reserve blocks for superuser
496 STORE_LE(sb->s_r_blocks_count, nreserved);
497 // ninodes
498 STORE_LE(sb->s_inodes_per_group, inodes_per_group);
499 STORE_LE(sb->s_inodes_count, inodes_per_group * ngroups);
500 STORE_LE(sb->s_free_inodes_count, inodes_per_group * ngroups - EXT2_GOOD_OLD_FIRST_INO);
501 // timestamps
502 timestamp = time(NULL);
503 STORE_LE(sb->s_mkfs_time, timestamp);
504 STORE_LE(sb->s_wtime, timestamp);
505 STORE_LE(sb->s_lastcheck, timestamp);
506 // misc. Values are chosen to match mke2fs 1.41.9
507 STORE_LE(sb->s_state, 1); // TODO: what's 1?
508 STORE_LE(sb->s_creator_os, EXT2_OS_LINUX);
509 STORE_LE(sb->s_checkinterval, 24*60*60 * 180); // 180 days
510 STORE_LE(sb->s_errors, EXT2_ERRORS_DEFAULT);
511 // mke2fs 1.41.9 also sets EXT3_FEATURE_COMPAT_RESIZE_INODE
512 // and if >= 0.5GB, EXT3_FEATURE_RO_COMPAT_LARGE_FILE.
513 // we use values which match "mke2fs -O ^resize_inode":
514 // in this case 1.41.9 never sets EXT3_FEATURE_RO_COMPAT_LARGE_FILE.
515 STORE_LE(sb->s_feature_compat, EXT2_FEATURE_COMPAT_SUPP
516 | (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
517 | (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
518 );
519 STORE_LE(sb->s_feature_incompat, EXT2_FEATURE_INCOMPAT_FILETYPE);
520 STORE_LE(sb->s_feature_ro_compat, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
521 STORE_LE(sb->s_flags, EXT2_FLAGS_UNSIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX);
522 generate_uuid(sb->s_uuid);
523 if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
524 STORE_LE(sb->s_def_hash_version, EXT2_HASH_HALF_MD4);
525 generate_uuid((uint8_t *)sb->s_hash_seed);
526 }
527 /*
528 * From e2fsprogs: add "jitter" to the superblock's check interval so that we
529 * don't check all the filesystems at the same time. We use a
530 * kludgy hack of using the UUID to derive a random jitter value.
531 */
532 STORE_LE(sb->s_max_mnt_count,
533 EXT2_DFL_MAX_MNT_COUNT
534 + (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));
535
536 // write the label
537 safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
538
539 // calculate filesystem skeleton structures
540 gd = xzalloc(group_desc_blocks * blocksize);
541 buf = xmalloc(blocksize);
542 sb->s_free_blocks_count = 0;
543 for (i = 0, pos = first_block, n = nblocks - first_block;
544 i < ngroups;
545 i++, pos += blocks_per_group, n -= blocks_per_group
546 ) {
547 uint32_t overhead = pos + (has_super(i) ? (1/*sb*/ + group_desc_blocks) : 0);
548 uint32_t free_blocks;
549 // fill group descriptors
550 STORE_LE(gd[i].bg_block_bitmap, overhead + 0);
551 STORE_LE(gd[i].bg_inode_bitmap, overhead + 1);
552 STORE_LE(gd[i].bg_inode_table, overhead + 2);
553 overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
554 gd[i].bg_free_inodes_count = inodes_per_group;
555 //STORE_LE(gd[i].bg_used_dirs_count, 0);
556 // N.B. both "/" and "/lost+found" are within the first block group
557 // "/" occupies 1 block, "/lost+found" occupies lost_and_found_blocks...
558 if (0 == i) {
559 // ... thus increased overhead for the first block group ...
560 overhead += 1 + lost_and_found_blocks;
561 // ... and 2 used directories
562 STORE_LE(gd[i].bg_used_dirs_count, 2);
563 // well known reserved inodes belong to the first block too
564 gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO;
565 }
566
567 // cache free block count of the group
568 free_blocks = (n < blocks_per_group ? n : blocks_per_group) - overhead;
569
570 // mark preallocated blocks as allocated
571//bb_info_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (free_blocks + overhead));
572 allocate(buf, blocksize,
573 // reserve "overhead" blocks
574 overhead,
575 // mark unused trailing blocks
576 blocks_per_group - (free_blocks + overhead)
577 );
578 // dump block bitmap
579 PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
580 STORE_LE(gd[i].bg_free_blocks_count, free_blocks);
581
582 // mark preallocated inodes as allocated
583 allocate(buf, blocksize,
584 // mark reserved inodes
585 inodes_per_group - gd[i].bg_free_inodes_count,
586 // mark unused trailing inodes
587 blocks_per_group - inodes_per_group
588 );
589 // dump inode bitmap
590 //PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
591 //but it's right after block bitmap, so we can just:
592 xwrite(fd, buf, blocksize);
593 STORE_LE(gd[i].bg_free_inodes_count, gd[i].bg_free_inodes_count);
594
595 // count overall free blocks
596 sb->s_free_blocks_count += free_blocks;
597 }
598 STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
599
600 // dump filesystem skeleton structures
601// printf("Writing superblocks and filesystem accounting information: ");
602 for (i = 0, pos = first_block; i < ngroups; i++, pos += blocks_per_group) {
603 // dump superblock and group descriptors and their backups
604 if (has_super(i)) {
605 // N.B. 1024 byte blocks are special
606 PUT(((uint64_t)pos * blocksize) + ((0 == i && 1024 != blocksize) ? 1024 : 0),
607 sb, 1024);
608 PUT(((uint64_t)pos * blocksize) + blocksize,
609 gd, group_desc_blocks * blocksize);
610 }
611 }
612
613 // zero boot sectors
614 memset(buf, 0, blocksize);
615 // Disabled: standard mke2fs doesn't do this, and
616 // on SPARC this destroys Sun disklabel.
617 // Users who need/want zeroing can easily do it with dd.
618 //PUT(0, buf, 1024); // N.B. 1024 <= blocksize, so buf[0..1023] contains zeros
619
620 // zero inode tables
621 for (i = 0; i < ngroups; ++i)
622 for (n = 0; n < inode_table_blocks; ++n)
623 PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize,
624 buf, blocksize);
625
626 // prepare directory inode
627 inode = (struct ext2_inode *)buf;
628 STORE_LE(inode->i_mode, S_IFDIR | S_IRWXU | S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH);
629 STORE_LE(inode->i_mtime, timestamp);
630 STORE_LE(inode->i_atime, timestamp);
631 STORE_LE(inode->i_ctime, timestamp);
632 STORE_LE(inode->i_size, blocksize);
633 // inode->i_blocks stores the number of 512 byte data blocks
634 // (512, because it goes directly to struct stat without scaling)
635 STORE_LE(inode->i_blocks, blocksize / 512);
636
637 // dump root dir inode
638 STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this inode
639 STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks);
640 PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * inodesize,
641 buf, inodesize);
642
643 // dump lost+found dir inode
644 STORE_LE(inode->i_links_count, 2); // both "/lost+found" and "/lost+found/." point to this inode
645 STORE_LE(inode->i_size, lost_and_found_blocks * blocksize);
646 STORE_LE(inode->i_blocks, (lost_and_found_blocks * blocksize) / 512);
647 n = FETCH_LE32(inode->i_block[0]) + 1;
648 for (i = 0; i < lost_and_found_blocks; ++i)
649 STORE_LE(inode->i_block[i], i + n); // use next block
650//bb_info_msg("LAST BLOCK USED[%u]", i + n);
651 PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_GOOD_OLD_FIRST_INO-1) * inodesize,
652 buf, inodesize);
653
654 // dump directories
655 memset(buf, 0, blocksize);
656 dir = (struct ext2_dir *)buf;
657
658 // dump 2nd+ blocks of "/lost+found"
659 STORE_LE(dir->rec_len1, blocksize); // e2fsck 1.41.4 compat (1.41.9 does not need this)
660 for (i = 1; i < lost_and_found_blocks; ++i)
661 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1+i) * blocksize,
662 buf, blocksize);
663
664 // dump 1st block of "/lost+found"
665 STORE_LE(dir->inode1, EXT2_GOOD_OLD_FIRST_INO);
666 STORE_LE(dir->rec_len1, 12);
667 STORE_LE(dir->name_len1, 1);
668 STORE_LE(dir->file_type1, EXT2_FT_DIR);
669 dir->name1[0] = '.';
670 STORE_LE(dir->inode2, EXT2_ROOT_INO);
671 STORE_LE(dir->rec_len2, blocksize - 12);
672 STORE_LE(dir->name_len2, 2);
673 STORE_LE(dir->file_type2, EXT2_FT_DIR);
674 dir->name2[0] = '.'; dir->name2[1] = '.';
675 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1) * blocksize, buf, blocksize);
676
677 // dump root dir block
678 STORE_LE(dir->inode1, EXT2_ROOT_INO);
679 STORE_LE(dir->rec_len2, 12);
680 STORE_LE(dir->inode3, EXT2_GOOD_OLD_FIRST_INO);
681 STORE_LE(dir->rec_len3, blocksize - 12 - 12);
682 STORE_LE(dir->name_len3, 10);
683 STORE_LE(dir->file_type3, EXT2_FT_DIR);
684 strcpy(dir->name3, "lost+found");
685 PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 0) * blocksize, buf, blocksize);
686
687 // cleanup
688 if (ENABLE_FEATURE_CLEAN_UP) {
689 free(buf);
690 free(gd);
691 free(sb);
692 }
693
694 xclose(fd);
695 return EXIT_SUCCESS;
696}
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