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 <stdio.h>
14 #include <string.h>
15 #if HAVE_UNISTD_H
16 #include <unistd.h>
17 #endif
18 #include <fcntl.h>
19 #include <time.h>
20 #if HAVE_SYS_STAT_H
21 #include <sys/stat.h>
22 #endif
23 #if HAVE_SYS_TYPES_H
24 #include <sys/types.h>
25 #endif
26
27 #include "ext2_fs.h"
28 #include "ext2fs.h"
29
30 #if defined(__linux__) && defined(EXT2_OS_LINUX)
31 #define CREATOR_OS EXT2_OS_LINUX
32 #else
33 #if defined(__GNU__) && defined(EXT2_OS_HURD)
34 #define CREATOR_OS EXT2_OS_HURD
35 #else
36 #if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD)
37 #define CREATOR_OS EXT2_OS_FREEBSD
38 #else
39 #if defined(LITES) && defined(EXT2_OS_LITES)
40 #define CREATOR_OS EXT2_OS_LITES
41 #else
42 #define CREATOR_OS EXT2_OS_LINUX /* by default */
43 #endif /* defined(LITES) && defined(EXT2_OS_LITES) */
44 #endif /* defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) */
45 #endif /* defined(__GNU__) && defined(EXT2_OS_HURD) */
46 #endif /* defined(__linux__) && defined(EXT2_OS_LINUX) */
47
48 /*
49 * Calculate the number of GDT blocks to reserve for online filesystem growth.
50 * The absolute maximum number of GDT blocks we can reserve is determined by
51 * the number of block pointers that can fit into a single block.
52 */
calc_reserved_gdt_blocks(ext2_filsys fs)53 static unsigned int calc_reserved_gdt_blocks(ext2_filsys fs)
54 {
55 struct ext2_super_block *sb = fs->super;
56 unsigned long bpg = sb->s_blocks_per_group;
57 unsigned int gdpb = EXT2_DESC_PER_BLOCK(sb);
58 unsigned long max_blocks = 0xffffffff;
59 unsigned long rsv_groups;
60 unsigned int rsv_gdb;
61
62 /* We set it at 1024x the current filesystem size, or
63 * the upper block count limit (2^32), whichever is lower.
64 */
65 if (ext2fs_blocks_count(sb) < max_blocks / 1024)
66 max_blocks = ext2fs_blocks_count(sb) * 1024;
67 /*
68 * ext2fs_div64_ceil() is unnecessary because max_blocks is
69 * max _GDT_ blocks, which is limited to 32 bits.
70 */
71 rsv_groups = ext2fs_div_ceil(max_blocks - sb->s_first_data_block, bpg);
72 rsv_gdb = ext2fs_div_ceil(rsv_groups, gdpb) - fs->desc_blocks;
73 if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb))
74 rsv_gdb = EXT2_ADDR_PER_BLOCK(sb);
75 #ifdef RES_GDT_DEBUG
76 printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %u\n",
77 max_blocks, rsv_groups, rsv_gdb);
78 #endif
79
80 return rsv_gdb;
81 }
82
ext2fs_initialize(const char * name,int flags,struct ext2_super_block * param,io_manager manager,ext2_filsys * ret_fs)83 errcode_t ext2fs_initialize(const char *name, int flags,
84 struct ext2_super_block *param,
85 io_manager manager, ext2_filsys *ret_fs)
86 {
87 ext2_filsys fs;
88 errcode_t retval;
89 struct ext2_super_block *super;
90 unsigned int rem;
91 unsigned int overhead = 0;
92 unsigned int ipg;
93 dgrp_t i;
94 blk64_t free_blocks;
95 blk_t numblocks;
96 int rsv_gdt;
97 int csum_flag;
98 int bigalloc_flag;
99 int io_flags;
100 unsigned reserved_inos;
101 char *buf = 0;
102 char c;
103 double reserved_ratio;
104
105 if (!param || !ext2fs_blocks_count(param))
106 return EXT2_ET_INVALID_ARGUMENT;
107
108 retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs);
109 if (retval)
110 return retval;
111
112 memset(fs, 0, sizeof(struct struct_ext2_filsys));
113 fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
114 fs->flags = flags | EXT2_FLAG_RW;
115 fs->umask = 022;
116 fs->default_bitmap_type = EXT2FS_BMAP64_RBTREE;
117 #ifdef WORDS_BIGENDIAN
118 fs->flags |= EXT2_FLAG_SWAP_BYTES;
119 #endif
120 io_flags = IO_FLAG_RW;
121 if (flags & EXT2_FLAG_EXCLUSIVE)
122 io_flags |= IO_FLAG_EXCLUSIVE;
123 if (flags & EXT2_FLAG_DIRECT_IO)
124 io_flags |= IO_FLAG_DIRECT_IO;
125 retval = manager->open(name, io_flags, &fs->io);
126 if (retval)
127 goto cleanup;
128 fs->image_io = fs->io;
129 fs->io->app_data = fs;
130 retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
131 if (retval)
132 goto cleanup;
133
134 strcpy(fs->device_name, name);
135 retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super);
136 if (retval)
137 goto cleanup;
138 fs->super = super;
139
140 memset(super, 0, SUPERBLOCK_SIZE);
141
142 #define set_field(field, default) (super->field = param->field ? \
143 param->field : (default))
144 #define assign_field(field) (super->field = param->field)
145
146 super->s_magic = EXT2_SUPER_MAGIC;
147 super->s_state = EXT2_VALID_FS;
148
149 bigalloc_flag = EXT2_HAS_RO_COMPAT_FEATURE(param,
150 EXT4_FEATURE_RO_COMPAT_BIGALLOC);
151
152 assign_field(s_log_block_size);
153
154 if (bigalloc_flag) {
155 set_field(s_log_cluster_size, super->s_log_block_size+4);
156 if (super->s_log_block_size > super->s_log_cluster_size) {
157 retval = EXT2_ET_INVALID_ARGUMENT;
158 goto cleanup;
159 }
160 } else
161 super->s_log_cluster_size = super->s_log_block_size;
162
163 set_field(s_first_data_block, super->s_log_cluster_size ? 0 : 1);
164 set_field(s_max_mnt_count, 0);
165 set_field(s_errors, EXT2_ERRORS_DEFAULT);
166 set_field(s_feature_compat, 0);
167 set_field(s_feature_incompat, 0);
168 set_field(s_feature_ro_compat, 0);
169 set_field(s_default_mount_opts, 0);
170 set_field(s_first_meta_bg, 0);
171 set_field(s_raid_stride, 0); /* default stride size: 0 */
172 set_field(s_raid_stripe_width, 0); /* default stripe width: 0 */
173 set_field(s_log_groups_per_flex, 0);
174 set_field(s_flags, 0);
175 if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
176 retval = EXT2_ET_UNSUPP_FEATURE;
177 goto cleanup;
178 }
179 if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) {
180 retval = EXT2_ET_RO_UNSUPP_FEATURE;
181 goto cleanup;
182 }
183
184 set_field(s_rev_level, EXT2_GOOD_OLD_REV);
185 if (super->s_rev_level >= EXT2_DYNAMIC_REV) {
186 set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
187 set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE);
188 if (super->s_inode_size >= sizeof(struct ext2_inode_large)) {
189 int extra_isize = sizeof(struct ext2_inode_large) -
190 EXT2_GOOD_OLD_INODE_SIZE;
191 set_field(s_min_extra_isize, extra_isize);
192 set_field(s_want_extra_isize, extra_isize);
193 }
194 } else {
195 super->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
196 super->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
197 }
198
199 set_field(s_checkinterval, 0);
200 super->s_mkfs_time = super->s_lastcheck = fs->now ? fs->now : time(NULL);
201
202 super->s_creator_os = CREATOR_OS;
203
204 fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(super);
205 fs->cluster_ratio_bits = super->s_log_cluster_size -
206 super->s_log_block_size;
207
208 if (bigalloc_flag) {
209 unsigned long long bpg;
210
211 if (param->s_blocks_per_group &&
212 param->s_clusters_per_group &&
213 ((param->s_clusters_per_group * EXT2FS_CLUSTER_RATIO(fs)) !=
214 param->s_blocks_per_group)) {
215 retval = EXT2_ET_INVALID_ARGUMENT;
216 goto cleanup;
217 }
218 if (param->s_clusters_per_group)
219 assign_field(s_clusters_per_group);
220 else if (param->s_blocks_per_group)
221 super->s_clusters_per_group =
222 param->s_blocks_per_group /
223 EXT2FS_CLUSTER_RATIO(fs);
224 else if (super->s_log_cluster_size + 15 < 32)
225 super->s_clusters_per_group = fs->blocksize * 8;
226 else
227 super->s_clusters_per_group = (fs->blocksize - 1) * 8;
228 if (super->s_clusters_per_group > EXT2_MAX_CLUSTERS_PER_GROUP(super))
229 super->s_clusters_per_group = EXT2_MAX_CLUSTERS_PER_GROUP(super);
230 bpg = EXT2FS_C2B(fs,
231 (unsigned long long) super->s_clusters_per_group);
232 if (bpg >= (((unsigned long long) 1) << 32)) {
233 retval = EXT2_ET_INVALID_ARGUMENT;
234 goto cleanup;
235 }
236 super->s_blocks_per_group = bpg;
237 } else {
238 set_field(s_blocks_per_group, fs->blocksize * 8);
239 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super))
240 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super);
241 super->s_clusters_per_group = super->s_blocks_per_group;
242 }
243
244 ext2fs_blocks_count_set(super, ext2fs_blocks_count(param) &
245 ~((blk64_t) EXT2FS_CLUSTER_MASK(fs)));
246 ext2fs_r_blocks_count_set(super, ext2fs_r_blocks_count(param));
247 if (ext2fs_r_blocks_count(super) >= ext2fs_blocks_count(param)) {
248 retval = EXT2_ET_INVALID_ARGUMENT;
249 goto cleanup;
250 }
251
252 set_field(s_mmp_update_interval, 0);
253
254 /*
255 * If we're creating an external journal device, we don't need
256 * to bother with the rest.
257 */
258 if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
259 fs->group_desc_count = 0;
260 ext2fs_mark_super_dirty(fs);
261 *ret_fs = fs;
262 return 0;
263 }
264
265 retry:
266 fs->group_desc_count = (dgrp_t) ext2fs_div64_ceil(
267 ext2fs_blocks_count(super) - super->s_first_data_block,
268 EXT2_BLOCKS_PER_GROUP(super));
269 if (fs->group_desc_count == 0) {
270 retval = EXT2_ET_TOOSMALL;
271 goto cleanup;
272 }
273
274 set_field(s_desc_size,
275 super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT ?
276 EXT2_MIN_DESC_SIZE_64BIT : 0);
277
278 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
279 EXT2_DESC_PER_BLOCK(super));
280
281 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize;
282
283 if (super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_64BIT &&
284 (ext2fs_blocks_count(super) / i) > (1ULL << 32))
285 set_field(s_inodes_count, ~0U);
286 else
287 set_field(s_inodes_count, ext2fs_blocks_count(super) / i);
288
289 /*
290 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
291 * that we have enough inodes for the filesystem(!)
292 */
293 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1)
294 super->s_inodes_count = EXT2_FIRST_INODE(super)+1;
295
296 /*
297 * There should be at least as many inodes as the user
298 * requested. Figure out how many inodes per group that
299 * should be. But make sure that we don't allocate more than
300 * one bitmap's worth of inodes each group.
301 */
302 ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count);
303 if (ipg > fs->blocksize * 8) {
304 if (!bigalloc_flag && super->s_blocks_per_group >= 256) {
305 /* Try again with slightly different parameters */
306 super->s_blocks_per_group -= 8;
307 ext2fs_blocks_count_set(super,
308 ext2fs_blocks_count(param));
309 super->s_clusters_per_group = super->s_blocks_per_group;
310 goto retry;
311 } else {
312 retval = EXT2_ET_TOO_MANY_INODES;
313 goto cleanup;
314 }
315 }
316
317 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super))
318 ipg = EXT2_MAX_INODES_PER_GROUP(super);
319
320 ipg_retry:
321 super->s_inodes_per_group = ipg;
322
323 /*
324 * Make sure the number of inodes per group completely fills
325 * the inode table blocks in the descriptor. If not, add some
326 * additional inodes/group. Waste not, want not...
327 */
328 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
329 EXT2_INODE_SIZE(super)) +
330 EXT2_BLOCK_SIZE(super) - 1) /
331 EXT2_BLOCK_SIZE(super));
332 super->s_inodes_per_group = ((fs->inode_blocks_per_group *
333 EXT2_BLOCK_SIZE(super)) /
334 EXT2_INODE_SIZE(super));
335 /*
336 * Finally, make sure the number of inodes per group is a
337 * multiple of 8. This is needed to simplify the bitmap
338 * splicing code.
339 */
340 if (super->s_inodes_per_group < 8)
341 super->s_inodes_per_group = 8;
342 super->s_inodes_per_group &= ~7;
343 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
344 EXT2_INODE_SIZE(super)) +
345 EXT2_BLOCK_SIZE(super) - 1) /
346 EXT2_BLOCK_SIZE(super));
347
348 /*
349 * adjust inode count to reflect the adjusted inodes_per_group
350 */
351 if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) {
352 ipg--;
353 goto ipg_retry;
354 }
355 super->s_inodes_count = super->s_inodes_per_group *
356 fs->group_desc_count;
357 super->s_free_inodes_count = super->s_inodes_count;
358
359 /*
360 * check the number of reserved group descriptor table blocks
361 */
362 if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE)
363 rsv_gdt = calc_reserved_gdt_blocks(fs);
364 else
365 rsv_gdt = 0;
366 set_field(s_reserved_gdt_blocks, rsv_gdt);
367 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) {
368 retval = EXT2_ET_RES_GDT_BLOCKS;
369 goto cleanup;
370 }
371
372 /*
373 * Calculate the maximum number of bookkeeping blocks per
374 * group. It includes the superblock, the block group
375 * descriptors, the block bitmap, the inode bitmap, the inode
376 * table, and the reserved gdt blocks.
377 */
378 overhead = (int) (3 + fs->inode_blocks_per_group +
379 fs->desc_blocks + super->s_reserved_gdt_blocks);
380
381 /* This can only happen if the user requested too many inodes */
382 if (overhead > super->s_blocks_per_group) {
383 retval = EXT2_ET_TOO_MANY_INODES;
384 goto cleanup;
385 }
386
387 /*
388 * See if the last group is big enough to support the
389 * necessary data structures. If not, we need to get rid of
390 * it. We need to recalculate the overhead for the last block
391 * group, since it might or might not have a superblock
392 * backup.
393 */
394 overhead = (int) (2 + fs->inode_blocks_per_group);
395 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
396 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
397 rem = ((ext2fs_blocks_count(super) - super->s_first_data_block) %
398 super->s_blocks_per_group);
399 if ((fs->group_desc_count == 1) && rem && (rem < overhead)) {
400 retval = EXT2_ET_TOOSMALL;
401 goto cleanup;
402 }
403 if (rem && (rem < overhead+50)) {
404 ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) -
405 rem);
406 /*
407 * If blocks count is changed, we need to recalculate
408 * reserved blocks count not to exceed 50%.
409 */
410 reserved_ratio = 100.0 * ext2fs_r_blocks_count(param) /
411 ext2fs_blocks_count(param);
412 ext2fs_r_blocks_count_set(super, reserved_ratio *
413 ext2fs_blocks_count(super) / 100.0);
414
415 goto retry;
416 }
417
418 /*
419 * At this point we know how big the filesystem will be. So
420 * we can do any and all allocations that depend on the block
421 * count.
422 */
423
424 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
425 if (retval)
426 goto cleanup;
427
428 strcpy(buf, "block bitmap for ");
429 strcat(buf, fs->device_name);
430 retval = ext2fs_allocate_subcluster_bitmap(fs, buf, &fs->block_map);
431 if (retval)
432 goto cleanup;
433
434 strcpy(buf, "inode bitmap for ");
435 strcat(buf, fs->device_name);
436 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
437 if (retval)
438 goto cleanup;
439
440 ext2fs_free_mem(&buf);
441
442 retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize,
443 &fs->group_desc);
444 if (retval)
445 goto cleanup;
446
447 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize);
448
449 /*
450 * Reserve the superblock and group descriptors for each
451 * group, and fill in the correct group statistics for group.
452 * Note that although the block bitmap, inode bitmap, and
453 * inode table have not been allocated (and in fact won't be
454 * by this routine), they are accounted for nevertheless.
455 *
456 * If FLEX_BG meta-data grouping is used, only account for the
457 * superblock and group descriptors (the inode tables and
458 * bitmaps will be accounted for when allocated).
459 */
460 free_blocks = 0;
461 csum_flag = EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
462 EXT4_FEATURE_RO_COMPAT_GDT_CSUM);
463 reserved_inos = super->s_first_ino;
464 for (i = 0; i < fs->group_desc_count; i++) {
465 /*
466 * Don't set the BLOCK_UNINIT group for the last group
467 * because the block bitmap needs to be padded.
468 */
469 if (csum_flag) {
470 if (i != fs->group_desc_count - 1)
471 ext2fs_bg_flags_set(fs, i,
472 EXT2_BG_BLOCK_UNINIT);
473 ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
474 numblocks = super->s_inodes_per_group;
475 if (reserved_inos) {
476 if (numblocks > reserved_inos) {
477 numblocks -= reserved_inos;
478 reserved_inos = 0;
479 } else {
480 reserved_inos -= numblocks;
481 numblocks = 0;
482 }
483 }
484 ext2fs_bg_itable_unused_set(fs, i, numblocks);
485 }
486 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
487 if (fs->super->s_log_groups_per_flex)
488 numblocks += 2 + fs->inode_blocks_per_group;
489
490 free_blocks += numblocks;
491 ext2fs_bg_free_blocks_count_set(fs, i, numblocks);
492 ext2fs_bg_free_inodes_count_set(fs, i, fs->super->s_inodes_per_group);
493 ext2fs_bg_used_dirs_count_set(fs, i, 0);
494 ext2fs_group_desc_csum_set(fs, i);
495 }
496 free_blocks &= ~EXT2FS_CLUSTER_MASK(fs);
497 ext2fs_free_blocks_count_set(super, free_blocks);
498
499 c = (char) 255;
500 if (((int) c) == -1) {
501 super->s_flags |= EXT2_FLAGS_SIGNED_HASH;
502 } else {
503 super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH;
504 }
505
506 ext2fs_mark_super_dirty(fs);
507 ext2fs_mark_bb_dirty(fs);
508 ext2fs_mark_ib_dirty(fs);
509
510 io_channel_set_blksize(fs->io, fs->blocksize);
511
512 *ret_fs = fs;
513 return 0;
514 cleanup:
515 free(buf);
516 ext2fs_free(fs);
517 return retval;
518 }
519