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