1 /*
2 * initialize.c --- initialize a filesystem handle given superblock
3 * parameters. Used by mke2fs when initializing a filesystem.
4 *
5 * Copyright (C) 1994, 1995, 1996 Theodore Ts'o.
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the GNU Library
9 * General Public License, version 2.
10 * %End-Header%
11 */
12
13 #include "config.h"
14 #include <stdio.h>
15 #include <string.h>
16 #if HAVE_UNISTD_H
17 #include <unistd.h>
18 #endif
19 #include <fcntl.h>
20 #include <time.h>
21 #if HAVE_SYS_STAT_H
22 #include <sys/stat.h>
23 #endif
24 #if HAVE_SYS_TYPES_H
25 #include <sys/types.h>
26 #endif
27
28 #include "ext2_fs.h"
29 #include "ext2fs.h"
30
31 #ifndef O_BINARY
32 #define O_BINARY 0
33 #endif
34
35 #if defined(__linux__) && defined(EXT2_OS_LINUX)
36 #define CREATOR_OS EXT2_OS_LINUX
37 #else
38 #if defined(__GNU__) && defined(EXT2_OS_HURD)
39 #define CREATOR_OS EXT2_OS_HURD
40 #else
41 #if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD)
42 #define CREATOR_OS EXT2_OS_FREEBSD
43 #else
44 #if defined(LITES) && defined(EXT2_OS_LITES)
45 #define CREATOR_OS EXT2_OS_LITES
46 #else
47 #define CREATOR_OS EXT2_OS_LINUX /* by default */
48 #endif /* defined(LITES) && defined(EXT2_OS_LITES) */
49 #endif /* defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) */
50 #endif /* defined(__GNU__) && defined(EXT2_OS_HURD) */
51 #endif /* defined(__linux__) && defined(EXT2_OS_LINUX) */
52
53 /*
54 * Calculate the number of GDT blocks to reserve for online filesystem growth.
55 * The absolute maximum number of GDT blocks we can reserve is determined by
56 * the number of block pointers that can fit into a single block.
57 */
calc_reserved_gdt_blocks(ext2_filsys fs)58 static unsigned int calc_reserved_gdt_blocks(ext2_filsys fs)
59 {
60 struct ext2_super_block *sb = fs->super;
61 unsigned long bpg = sb->s_blocks_per_group;
62 unsigned int gdpb = EXT2_DESC_PER_BLOCK(sb);
63 unsigned long max_blocks = 0xffffffff;
64 unsigned long rsv_groups;
65 unsigned int rsv_gdb;
66
67 /* We set it at 1024x the current filesystem size, or
68 * the upper block count limit (2^32), whichever is lower.
69 */
70 if (ext2fs_blocks_count(sb) < max_blocks / 1024)
71 max_blocks = ext2fs_blocks_count(sb) * 1024;
72 /*
73 * ext2fs_div64_ceil() is unnecessary because max_blocks is
74 * max _GDT_ blocks, which is limited to 32 bits.
75 */
76 rsv_groups = ext2fs_div_ceil(max_blocks - sb->s_first_data_block, bpg);
77 rsv_gdb = ext2fs_div_ceil(rsv_groups, gdpb) - fs->desc_blocks;
78 if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb))
79 rsv_gdb = EXT2_ADDR_PER_BLOCK(sb);
80 #ifdef RES_GDT_DEBUG
81 printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %u\n",
82 max_blocks, rsv_groups, rsv_gdb);
83 #endif
84
85 return rsv_gdb;
86 }
87
ext2fs_initialize(const char * name,int flags,struct ext2_super_block * param,io_manager manager,ext2_filsys * ret_fs)88 errcode_t ext2fs_initialize(const char *name, int flags,
89 struct ext2_super_block *param,
90 io_manager manager, ext2_filsys *ret_fs)
91 {
92 ext2_filsys fs;
93 errcode_t retval;
94 struct ext2_super_block *super;
95 unsigned int rem;
96 unsigned int overhead = 0;
97 unsigned int ipg;
98 dgrp_t i;
99 blk64_t free_blocks;
100 blk_t numblocks;
101 int rsv_gdt;
102 int csum_flag;
103 int bigalloc_flag;
104 int io_flags;
105 int has_bg;
106 unsigned reserved_inos;
107 char *buf = 0;
108 char c;
109 double reserved_ratio;
110 char *time_env;
111
112 if (!param || !ext2fs_blocks_count(param))
113 return EXT2_ET_INVALID_ARGUMENT;
114
115 retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs);
116 if (retval)
117 return retval;
118
119 memset(fs, 0, sizeof(struct struct_ext2_filsys));
120 fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
121 fs->flags = flags | EXT2_FLAG_RW;
122 fs->umask = 022;
123 fs->default_bitmap_type = EXT2FS_BMAP64_RBTREE;
124 #ifdef WORDS_BIGENDIAN
125 fs->flags |= EXT2_FLAG_SWAP_BYTES;
126 #endif
127
128 time_env = getenv("E2FSPROGS_FAKE_TIME");
129 if (time_env)
130 fs->now = strtoul(time_env, NULL, 0);
131
132 io_flags = IO_FLAG_RW;
133 if (flags & EXT2_FLAG_EXCLUSIVE)
134 io_flags |= IO_FLAG_EXCLUSIVE;
135 if (flags & EXT2_FLAG_DIRECT_IO)
136 io_flags |= IO_FLAG_DIRECT_IO;
137 io_flags |= O_BINARY;
138 retval = manager->open(name, io_flags, &fs->io);
139 if (retval)
140 goto cleanup;
141 fs->image_io = fs->io;
142 fs->io->app_data = fs;
143 retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
144 if (retval)
145 goto cleanup;
146
147 strcpy(fs->device_name, name);
148 retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super);
149 if (retval)
150 goto cleanup;
151 fs->super = super;
152
153 memset(super, 0, SUPERBLOCK_SIZE);
154
155 #define set_field(field, default) (super->field = param->field ? \
156 param->field : (default))
157 #define assign_field(field) (super->field = param->field)
158
159 super->s_magic = EXT2_SUPER_MAGIC;
160 super->s_state = EXT2_VALID_FS;
161
162 bigalloc_flag = ext2fs_has_feature_bigalloc(param);
163
164 assign_field(s_log_block_size);
165
166 if (bigalloc_flag) {
167 set_field(s_log_cluster_size, super->s_log_block_size+4);
168 if (super->s_log_block_size > super->s_log_cluster_size) {
169 retval = EXT2_ET_INVALID_ARGUMENT;
170 goto cleanup;
171 }
172 } else
173 super->s_log_cluster_size = super->s_log_block_size;
174
175 set_field(s_first_data_block, super->s_log_cluster_size ? 0 : 1);
176 set_field(s_max_mnt_count, 0);
177 set_field(s_errors, EXT2_ERRORS_DEFAULT);
178 set_field(s_feature_compat, 0);
179 set_field(s_feature_incompat, 0);
180 set_field(s_feature_ro_compat, 0);
181 set_field(s_default_mount_opts, 0);
182 set_field(s_first_meta_bg, 0);
183 set_field(s_raid_stride, 0); /* default stride size: 0 */
184 set_field(s_raid_stripe_width, 0); /* default stripe width: 0 */
185 set_field(s_log_groups_per_flex, 0);
186 set_field(s_flags, 0);
187 assign_field(s_backup_bgs[0]);
188 assign_field(s_backup_bgs[1]);
189 if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
190 retval = EXT2_ET_UNSUPP_FEATURE;
191 goto cleanup;
192 }
193 if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) {
194 retval = EXT2_ET_RO_UNSUPP_FEATURE;
195 goto cleanup;
196 }
197
198 set_field(s_rev_level, EXT2_GOOD_OLD_REV);
199 if (super->s_rev_level >= EXT2_DYNAMIC_REV) {
200 set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
201 set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE);
202 if (super->s_inode_size >= sizeof(struct ext2_inode_large)) {
203 int extra_isize = sizeof(struct ext2_inode_large) -
204 EXT2_GOOD_OLD_INODE_SIZE;
205 set_field(s_min_extra_isize, extra_isize);
206 set_field(s_want_extra_isize, extra_isize);
207 }
208 } else {
209 super->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
210 super->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
211 }
212
213 set_field(s_checkinterval, 0);
214 super->s_mkfs_time = super->s_lastcheck = fs->now ? fs->now : time(NULL);
215
216 super->s_creator_os = CREATOR_OS;
217
218 fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(super);
219 fs->cluster_ratio_bits = super->s_log_cluster_size -
220 super->s_log_block_size;
221
222 if (bigalloc_flag) {
223 unsigned long long bpg;
224
225 if (param->s_blocks_per_group &&
226 param->s_clusters_per_group &&
227 ((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) !=
228 param->s_blocks_per_group)) {
229 retval = EXT2_ET_INVALID_ARGUMENT;
230 goto cleanup;
231 }
232 if (param->s_clusters_per_group)
233 assign_field(s_clusters_per_group);
234 else if (param->s_blocks_per_group)
235 super->s_clusters_per_group =
236 param->s_blocks_per_group /
237 EXT2FS_CLUSTER_RATIO(fs);
238 else if (super->s_log_cluster_size + 15 < 32)
239 super->s_clusters_per_group = fs->blocksize * 8;
240 else
241 super->s_clusters_per_group = (fs->blocksize - 1) * 8;
242 if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super))
243 super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super);
244 bpg = EXT2FS_C2B(fs,
245 (unsigned long long) super->s_clusters_per_group);
246 if (bpg >= (((unsigned long long) 1) << 32)) {
247 retval = EXT2_ET_INVALID_ARGUMENT;
248 goto cleanup;
249 }
250 super->s_blocks_per_group = bpg;
251 } else {
252 set_field(s_blocks_per_group, fs->blocksize * 8);
253 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super))
254 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super);
255 super->s_clusters_per_group = super->s_blocks_per_group;
256 }
257
258 ext2fs_blocks_count_set(super, ext2fs_blocks_count(param) &
259 ~((blk64_t) EXT2FS_CLUSTER_MASK(fs)));
260 ext2fs_r_blocks_count_set(super, ext2fs_r_blocks_count(param));
261 if (ext2fs_r_blocks_count(super) >= ext2fs_blocks_count(param)) {
262 retval = EXT2_ET_INVALID_ARGUMENT;
263 goto cleanup;
264 }
265
266 set_field(s_mmp_update_interval, 0);
267
268 /*
269 * If we're creating an external journal device, we don't need
270 * to bother with the rest.
271 */
272 if (ext2fs_has_feature_journal_dev(super)) {
273 fs->group_desc_count = 0;
274 ext2fs_mark_super_dirty(fs);
275 *ret_fs = fs;
276 return 0;
277 }
278
279 retry:
280 fs->group_desc_count = (dgrp_t) ext2fs_div64_ceil(
281 ext2fs_blocks_count(super) - super->s_first_data_block,
282 EXT2_BLOCKS_PER_GROUP(super));
283 if (fs->group_desc_count == 0) {
284 retval = EXT2_ET_TOOSMALL;
285 goto cleanup;
286 }
287
288 set_field(s_desc_size,
289 ext2fs_has_feature_64bit(super) ?
290 EXT2_MIN_DESC_SIZE_64BIT : 0);
291
292 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
293 EXT2_DESC_PER_BLOCK(super));
294
295 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize;
296
297 if (ext2fs_has_feature_64bit(super) &&
298 (ext2fs_blocks_count(super) / i) >= (1ULL << 32))
299 set_field(s_inodes_count, ~0U);
300 else
301 set_field(s_inodes_count, ext2fs_blocks_count(super) / i);
302
303 /*
304 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
305 * that we have enough inodes for the filesystem(!)
306 */
307 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1)
308 super->s_inodes_count = EXT2_FIRST_INODE(super)+1;
309
310 /*
311 * There should be at least as many inodes as the user
312 * requested. Figure out how many inodes per group that
313 * should be. But make sure that we don't allocate more than
314 * one bitmap's worth of inodes each group.
315 */
316 ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count);
317 if (ipg > fs->blocksize * 8) {
318 if (!bigalloc_flag && super->s_blocks_per_group >= 256) {
319 /* Try again with slightly different parameters */
320 super->s_blocks_per_group -= 8;
321 ext2fs_blocks_count_set(super,
322 ext2fs_blocks_count(param));
323 super->s_clusters_per_group = super->s_blocks_per_group;
324 goto retry;
325 } else {
326 retval = EXT2_ET_TOO_MANY_INODES;
327 goto cleanup;
328 }
329 }
330
331 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super))
332 ipg = EXT2_MAX_INODES_PER_GROUP(super);
333
334 ipg_retry:
335 super->s_inodes_per_group = ipg;
336
337 /*
338 * Make sure the number of inodes per group completely fills
339 * the inode table blocks in the descriptor. If not, add some
340 * additional inodes/group. Waste not, want not...
341 */
342 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
343 EXT2_INODE_SIZE(super)) +
344 EXT2_BLOCK_SIZE(super) - 1) /
345 EXT2_BLOCK_SIZE(super));
346 super->s_inodes_per_group = ((fs->inode_blocks_per_group *
347 EXT2_BLOCK_SIZE(super)) /
348 EXT2_INODE_SIZE(super));
349 /*
350 * Finally, make sure the number of inodes per group is a
351 * multiple of 8. This is needed to simplify the bitmap
352 * splicing code.
353 */
354 if (super->s_inodes_per_group < 8)
355 super->s_inodes_per_group = 8;
356 super->s_inodes_per_group &= ~7;
357 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
358 EXT2_INODE_SIZE(super)) +
359 EXT2_BLOCK_SIZE(super) - 1) /
360 EXT2_BLOCK_SIZE(super));
361
362 /*
363 * adjust inode count to reflect the adjusted inodes_per_group
364 */
365 if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) {
366 ipg--;
367 goto ipg_retry;
368 }
369 super->s_inodes_count = super->s_inodes_per_group *
370 fs->group_desc_count;
371 super->s_free_inodes_count = super->s_inodes_count;
372
373 /*
374 * check the number of reserved group descriptor table blocks
375 */
376 if (ext2fs_has_feature_resize_inode(super))
377 rsv_gdt = calc_reserved_gdt_blocks(fs);
378 else
379 rsv_gdt = 0;
380 set_field(s_reserved_gdt_blocks, rsv_gdt);
381 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) {
382 retval = EXT2_ET_RES_GDT_BLOCKS;
383 goto cleanup;
384 }
385 /* Enable meta_bg if we'd lose more than 3/4 of a BG to GDT blocks. */
386 if (super->s_reserved_gdt_blocks + fs->desc_blocks >
387 super->s_blocks_per_group * 3 / 4) {
388 ext2fs_set_feature_meta_bg(fs->super);
389 ext2fs_clear_feature_resize_inode(fs->super);
390 set_field(s_reserved_gdt_blocks, 0);
391 }
392
393 /*
394 * Calculate the maximum number of bookkeeping blocks per
395 * group. It includes the superblock, the block group
396 * descriptors, the block bitmap, the inode bitmap, the inode
397 * table, and the reserved gdt blocks.
398 */
399 overhead = (int) (3 + fs->inode_blocks_per_group +
400 super->s_reserved_gdt_blocks);
401
402 if (ext2fs_has_feature_meta_bg(fs->super))
403 overhead++;
404 else
405 overhead += fs->desc_blocks;
406
407 /* This can only happen if the user requested too many inodes */
408 if (overhead > super->s_blocks_per_group) {
409 retval = EXT2_ET_TOO_MANY_INODES;
410 goto cleanup;
411 }
412
413 /*
414 * See if the last group is big enough to support the
415 * necessary data structures. If not, we need to get rid of
416 * it. We need to recalculate the overhead for the last block
417 * group, since it might or might not have a superblock
418 * backup.
419 */
420 overhead = (int) (2 + fs->inode_blocks_per_group);
421 has_bg = 0;
422 if (ext2fs_has_feature_sparse_super2(super)) {
423 /*
424 * We have to do this manually since
425 * super->s_backup_bgs hasn't been set up yet.
426 */
427 if (fs->group_desc_count == 2)
428 has_bg = param->s_backup_bgs[0] != 0;
429 else
430 has_bg = param->s_backup_bgs[1] != 0;
431 } else
432 has_bg = ext2fs_bg_has_super(fs, fs->group_desc_count - 1);
433 if (has_bg)
434 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
435 rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) %
436 super->s_blocks_per_group);
437 if ((fs->group_desc_count == 1) && rem && (rem < overhead)) {
438 retval = EXT2_ET_TOOSMALL;
439 goto cleanup;
440 }
441 if (rem && (rem < overhead+50)) {
442 ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) -
443 rem);
444 /*
445 * If blocks count is changed, we need to recalculate
446 * reserved blocks count not to exceed 50%.
447 */
448 reserved_ratio = 100.0 * ext2fs_r_blocks_count(param) /
449 ext2fs_blocks_count(param);
450 ext2fs_r_blocks_count_set(super, reserved_ratio *
451 ext2fs_blocks_count(super) / 100.0);
452
453 goto retry;
454 }
455
456 /*
457 * At this point we know how big the filesystem will be. So
458 * we can do any and all allocations that depend on the block
459 * count.
460 */
461
462 /* Set up the locations of the backup superblocks */
463 if (ext2fs_has_feature_sparse_super2(super)) {
464 if (super->s_backup_bgs[0] >= fs->group_desc_count)
465 super->s_backup_bgs[0] = fs->group_desc_count - 1;
466 if (super->s_backup_bgs[1] >= fs->group_desc_count)
467 super->s_backup_bgs[1] = fs->group_desc_count - 1;
468 if (super->s_backup_bgs[0] == super->s_backup_bgs[1])
469 super->s_backup_bgs[1] = 0;
470 if (super->s_backup_bgs[0] > super->s_backup_bgs[1]) {
471 __u32 t = super->s_backup_bgs[0];
472 super->s_backup_bgs[0] = super->s_backup_bgs[1];
473 super->s_backup_bgs[1] = t;
474 }
475 }
476
477 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
478 if (retval)
479 goto cleanup;
480
481 strcpy(buf, "block bitmap for ");
482 strcat(buf, fs->device_name);
483 retval = ext2fs_allocate_subcluster_bitmap(fs, buf, &fs->block_map);
484 if (retval)
485 goto cleanup;
486
487 strcpy(buf, "inode bitmap for ");
488 strcat(buf, fs->device_name);
489 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
490 if (retval)
491 goto cleanup;
492
493 ext2fs_free_mem(&buf);
494
495 retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize,
496 &fs->group_desc);
497 if (retval)
498 goto cleanup;
499
500 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize);
501
502 /*
503 * Reserve the superblock and group descriptors for each
504 * group, and fill in the correct group statistics for group.
505 * Note that although the block bitmap, inode bitmap, and
506 * inode table have not been allocated (and in fact won't be
507 * by this routine), they are accounted for nevertheless.
508 *
509 * If FLEX_BG meta-data grouping is used, only account for the
510 * superblock and group descriptors (the inode tables and
511 * bitmaps will be accounted for when allocated).
512 */
513 free_blocks = 0;
514 csum_flag = ext2fs_has_group_desc_csum(fs);
515 reserved_inos = super->s_first_ino;
516 for (i = 0; i < fs->group_desc_count; i++) {
517 /*
518 * Don't set the BLOCK_UNINIT group for the last group
519 * because the block bitmap needs to be padded.
520 */
521 if (csum_flag) {
522 if (i != fs->group_desc_count - 1)
523 ext2fs_bg_flags_set(fs, i,
524 EXT2_BG_BLOCK_UNINIT);
525 ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
526 numblocks = super->s_inodes_per_group;
527 if (reserved_inos) {
528 if (numblocks > reserved_inos) {
529 numblocks -= reserved_inos;
530 reserved_inos = 0;
531 } else {
532 reserved_inos -= numblocks;
533 numblocks = 0;
534 }
535 }
536 ext2fs_bg_itable_unused_set(fs, i, numblocks);
537 }
538 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
539 if (fs->super->s_log_groups_per_flex)
540 numblocks += 2 + fs->inode_blocks_per_group;
541
542 free_blocks += numblocks;
543 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
544 ext2fs_bg_free_inodes_count_set(fs, i, fs->super->s_inodes_per_group);
545 ext2fs_bg_used_dirs_count_set(fs, i, 0);
546 ext2fs_group_desc_csum_set(fs, i);
547 }
548 free_blocks &= ~EXT2FS_CLUSTER_MASK(fs);
549 ext2fs_free_blocks_count_set(super, free_blocks);
550
551 c = (char) 255;
552 if (((int) c) == -1) {
553 super->s_flags |= EXT2_FLAGS_SIGNED_HASH;
554 } else {
555 super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH;
556 }
557
558 ext2fs_mark_super_dirty(fs);
559 ext2fs_mark_bb_dirty(fs);
560 ext2fs_mark_ib_dirty(fs);
561
562 io_channel_set_blksize(fs->io, fs->blocksize);
563
564 *ret_fs = fs;
565 return 0;
566 cleanup:
567 free(buf);
568 ext2fs_free(fs);
569 return retval;
570 }
571