source: MondoRescue/branches/stable/mindi-busybox/e2fsprogs/ext2fs/initialize.c@ 821

Last change on this file since 821 was 821, checked in by Bruno Cornec, 18 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)
File size: 11.4 KB
Line 
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 Public
9 * License.
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 * Note we override the kernel include file's idea of what the default
50 * check interval (never) should be. It's a good idea to check at
51 * least *occasionally*, specially since servers will never rarely get
52 * to reboot, since Linux is so robust these days. :-)
53 *
54 * 180 days (six months) seems like a good value.
55 */
56#ifdef EXT2_DFL_CHECKINTERVAL
57#undef EXT2_DFL_CHECKINTERVAL
58#endif
59#define EXT2_DFL_CHECKINTERVAL (86400L * 180L)
60
61/*
62 * Calculate the number of GDT blocks to reserve for online filesystem growth.
63 * The absolute maximum number of GDT blocks we can reserve is determined by
64 * the number of block pointers that can fit into a single block.
65 */
66static int calc_reserved_gdt_blocks(ext2_filsys fs)
67{
68 struct ext2_super_block *sb = fs->super;
69 unsigned long bpg = sb->s_blocks_per_group;
70 unsigned int gdpb = fs->blocksize / sizeof(struct ext2_group_desc);
71 unsigned long max_blocks = 0xffffffff;
72 unsigned long rsv_groups;
73 int rsv_gdb;
74
75 /* We set it at 1024x the current filesystem size, or
76 * the upper block count limit (2^32), whichever is lower.
77 */
78 if (sb->s_blocks_count < max_blocks / 1024)
79 max_blocks = sb->s_blocks_count * 1024;
80 rsv_groups = (max_blocks - sb->s_first_data_block + bpg - 1) / bpg;
81 rsv_gdb = (rsv_groups + gdpb - 1) / gdpb - fs->desc_blocks;
82 if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb))
83 rsv_gdb = EXT2_ADDR_PER_BLOCK(sb);
84#ifdef RES_GDT_DEBUG
85 printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %lu\n",
86 max_blocks, rsv_groups, rsv_gdb);
87#endif
88
89 return rsv_gdb;
90}
91
92errcode_t ext2fs_initialize(const char *name, int flags,
93 struct ext2_super_block *param,
94 io_manager manager, ext2_filsys *ret_fs)
95{
96 ext2_filsys fs;
97 errcode_t retval;
98 struct ext2_super_block *super;
99 int frags_per_block;
100 unsigned int rem;
101 unsigned int overhead = 0;
102 blk_t group_block;
103 unsigned int ipg;
104 dgrp_t i;
105 blk_t numblocks;
106 int rsv_gdt;
107 char *buf;
108
109 if (!param || !param->s_blocks_count)
110 return EXT2_ET_INVALID_ARGUMENT;
111
112 retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs);
113 if (retval)
114 return retval;
115
116 memset(fs, 0, sizeof(struct struct_ext2_filsys));
117 fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
118 fs->flags = flags | EXT2_FLAG_RW;
119 fs->umask = 022;
120#ifdef WORDS_BIGENDIAN
121 fs->flags |= EXT2_FLAG_SWAP_BYTES;
122#endif
123 retval = manager->open(name, IO_FLAG_RW, &fs->io);
124 if (retval)
125 goto cleanup;
126 fs->image_io = fs->io;
127 fs->io->app_data = fs;
128 retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
129 if (retval)
130 goto cleanup;
131
132 strcpy(fs->device_name, name);
133 retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super);
134 if (retval)
135 goto cleanup;
136 fs->super = super;
137
138 memset(super, 0, SUPERBLOCK_SIZE);
139
140#define set_field(field, default) (super->field = param->field ? \
141 param->field : (default))
142
143 super->s_magic = EXT2_SUPER_MAGIC;
144 super->s_state = EXT2_VALID_FS;
145
146 set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */
147 set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */
148 set_field(s_first_data_block, super->s_log_block_size ? 0 : 1);
149 set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT);
150 set_field(s_errors, EXT2_ERRORS_DEFAULT);
151 set_field(s_feature_compat, 0);
152 set_field(s_feature_incompat, 0);
153 set_field(s_feature_ro_compat, 0);
154 set_field(s_first_meta_bg, 0);
155 if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
156 retval = EXT2_ET_UNSUPP_FEATURE;
157 goto cleanup;
158 }
159 if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) {
160 retval = EXT2_ET_RO_UNSUPP_FEATURE;
161 goto cleanup;
162 }
163
164 set_field(s_rev_level, EXT2_GOOD_OLD_REV);
165 if (super->s_rev_level >= EXT2_DYNAMIC_REV) {
166 set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
167 set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE);
168 }
169
170 set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL);
171 super->s_mkfs_time = super->s_lastcheck = time(NULL);
172
173 super->s_creator_os = CREATOR_OS;
174
175 fs->blocksize = EXT2_BLOCK_SIZE(super);
176 fs->fragsize = EXT2_FRAG_SIZE(super);
177 frags_per_block = fs->blocksize / fs->fragsize;
178
179 /* default: (fs->blocksize*8) blocks/group, up to 2^16 (GDT limit) */
180 set_field(s_blocks_per_group, fs->blocksize * 8);
181 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super))
182 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super);
183 super->s_frags_per_group = super->s_blocks_per_group * frags_per_block;
184
185 super->s_blocks_count = param->s_blocks_count;
186 super->s_r_blocks_count = param->s_r_blocks_count;
187 if (super->s_r_blocks_count >= param->s_blocks_count) {
188 retval = EXT2_ET_INVALID_ARGUMENT;
189 goto cleanup;
190 }
191
192 /*
193 * If we're creating an external journal device, we don't need
194 * to bother with the rest.
195 */
196 if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
197 fs->group_desc_count = 0;
198 ext2fs_mark_super_dirty(fs);
199 *ret_fs = fs;
200 return 0;
201 }
202
203retry:
204 fs->group_desc_count = (super->s_blocks_count -
205 super->s_first_data_block +
206 EXT2_BLOCKS_PER_GROUP(super) - 1)
207 / EXT2_BLOCKS_PER_GROUP(super);
208 if (fs->group_desc_count == 0) {
209 retval = EXT2_ET_TOOSMALL;
210 goto cleanup;
211 }
212 fs->desc_blocks = (fs->group_desc_count +
213 EXT2_DESC_PER_BLOCK(super) - 1)
214 / EXT2_DESC_PER_BLOCK(super);
215
216 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize;
217 set_field(s_inodes_count, super->s_blocks_count / i);
218
219 /*
220 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
221 * that we have enough inodes for the filesystem(!)
222 */
223 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1)
224 super->s_inodes_count = EXT2_FIRST_INODE(super)+1;
225
226 /*
227 * There should be at least as many inodes as the user
228 * requested. Figure out how many inodes per group that
229 * should be. But make sure that we don't allocate more than
230 * one bitmap's worth of inodes each group.
231 */
232 ipg = (super->s_inodes_count + fs->group_desc_count - 1) /
233 fs->group_desc_count;
234 if (ipg > fs->blocksize * 8) {
235 if (super->s_blocks_per_group >= 256) {
236 /* Try again with slightly different parameters */
237 super->s_blocks_per_group -= 8;
238 super->s_blocks_count = param->s_blocks_count;
239 super->s_frags_per_group = super->s_blocks_per_group *
240 frags_per_block;
241 goto retry;
242 } else
243 return EXT2_ET_TOO_MANY_INODES;
244 }
245
246 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super))
247 ipg = EXT2_MAX_INODES_PER_GROUP(super);
248
249 super->s_inodes_per_group = ipg;
250 if (super->s_inodes_count > ipg * fs->group_desc_count)
251 super->s_inodes_count = ipg * fs->group_desc_count;
252
253 /*
254 * Make sure the number of inodes per group completely fills
255 * the inode table blocks in the descriptor. If not, add some
256 * additional inodes/group. Waste not, want not...
257 */
258 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
259 EXT2_INODE_SIZE(super)) +
260 EXT2_BLOCK_SIZE(super) - 1) /
261 EXT2_BLOCK_SIZE(super));
262 super->s_inodes_per_group = ((fs->inode_blocks_per_group *
263 EXT2_BLOCK_SIZE(super)) /
264 EXT2_INODE_SIZE(super));
265 /*
266 * Finally, make sure the number of inodes per group is a
267 * multiple of 8. This is needed to simplify the bitmap
268 * splicing code.
269 */
270 super->s_inodes_per_group &= ~7;
271 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
272 EXT2_INODE_SIZE(super)) +
273 EXT2_BLOCK_SIZE(super) - 1) /
274 EXT2_BLOCK_SIZE(super));
275
276 /*
277 * adjust inode count to reflect the adjusted inodes_per_group
278 */
279 super->s_inodes_count = super->s_inodes_per_group *
280 fs->group_desc_count;
281 super->s_free_inodes_count = super->s_inodes_count;
282
283 /*
284 * check the number of reserved group descriptor table blocks
285 */
286 if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE)
287 rsv_gdt = calc_reserved_gdt_blocks(fs);
288 else
289 rsv_gdt = 0;
290 set_field(s_reserved_gdt_blocks, rsv_gdt);
291 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) {
292 retval = EXT2_ET_RES_GDT_BLOCKS;
293 goto cleanup;
294 }
295
296 /*
297 * Overhead is the number of bookkeeping blocks per group. It
298 * includes the superblock backup, the group descriptor
299 * backups, the inode bitmap, the block bitmap, and the inode
300 * table.
301 */
302
303 overhead = (int) (2 + fs->inode_blocks_per_group);
304
305 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
306 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
307
308 /* This can only happen if the user requested too many inodes */
309 if (overhead > super->s_blocks_per_group)
310 return EXT2_ET_TOO_MANY_INODES;
311
312 /*
313 * See if the last group is big enough to support the
314 * necessary data structures. If not, we need to get rid of
315 * it.
316 */
317 rem = ((super->s_blocks_count - super->s_first_data_block) %
318 super->s_blocks_per_group);
319 if ((fs->group_desc_count == 1) && rem && (rem < overhead))
320 return EXT2_ET_TOOSMALL;
321 if (rem && (rem < overhead+50)) {
322 super->s_blocks_count -= rem;
323 goto retry;
324 }
325
326 /*
327 * At this point we know how big the filesystem will be. So
328 * we can do any and all allocations that depend on the block
329 * count.
330 */
331
332 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
333 if (retval)
334 goto cleanup;
335
336 sprintf(buf, "block bitmap for %s", fs->device_name);
337 retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
338 if (retval)
339 goto cleanup;
340
341 sprintf(buf, "inode bitmap for %s", fs->device_name);
342 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
343 if (retval)
344 goto cleanup;
345
346 ext2fs_free_mem(&buf);
347
348 retval = ext2fs_get_mem((size_t) fs->desc_blocks * fs->blocksize,
349 &fs->group_desc);
350 if (retval)
351 goto cleanup;
352
353 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize);
354
355 /*
356 * Reserve the superblock and group descriptors for each
357 * group, and fill in the correct group statistics for group.
358 * Note that although the block bitmap, inode bitmap, and
359 * inode table have not been allocated (and in fact won't be
360 * by this routine), they are accounted for nevertheless.
361 */
362 group_block = super->s_first_data_block;
363 super->s_free_blocks_count = 0;
364 for (i = 0; i < fs->group_desc_count; i++) {
365 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
366
367 super->s_free_blocks_count += numblocks;
368 fs->group_desc[i].bg_free_blocks_count = numblocks;
369 fs->group_desc[i].bg_free_inodes_count =
370 fs->super->s_inodes_per_group;
371 fs->group_desc[i].bg_used_dirs_count = 0;
372
373 group_block += super->s_blocks_per_group;
374 }
375
376 ext2fs_mark_super_dirty(fs);
377 ext2fs_mark_bb_dirty(fs);
378 ext2fs_mark_ib_dirty(fs);
379
380 io_channel_set_blksize(fs->io, fs->blocksize);
381
382 *ret_fs = fs;
383 return 0;
384cleanup:
385 ext2fs_free(fs);
386 return retval;
387}
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