source: MondoRescue/branches/3.2/mindi-busybox/e2fsprogs/old_e2fsprogs/ext2fs/initialize.c@ 3186

Last change on this file since 3186 was 1765, checked in by Bruno Cornec, 16 years ago

Update to busybox 1.7.2
  • Property svn:eol-style set to native
File size: 11.5 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * initialize.c --- initialize a filesystem handle given superblock
4 * parameters. Used by mke2fs when initializing a filesystem.
5 *
6 * Copyright (C) 1994, 1995, 1996 Theodore Ts'o.
7 *
8 * %Begin-Header%
9 * This file may be redistributed under the terms of the GNU Public
10 * License.
11 * %End-Header%
12 */
13
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 * Note we override the kernel include file's idea of what the default
51 * check interval (never) should be. It's a good idea to check at
52 * least *occasionally*, specially since servers will never rarely get
53 * to reboot, since Linux is so robust these days. :-)
54 *
55 * 180 days (six months) seems like a good value.
56 */
57#ifdef EXT2_DFL_CHECKINTERVAL
58#undef EXT2_DFL_CHECKINTERVAL
59#endif
60#define EXT2_DFL_CHECKINTERVAL (86400L * 180L)
61
62/*
63 * Calculate the number of GDT blocks to reserve for online filesystem growth.
64 * The absolute maximum number of GDT blocks we can reserve is determined by
65 * the number of block pointers that can fit into a single block.
66 */
67static int calc_reserved_gdt_blocks(ext2_filsys fs)
68{
69 struct ext2_super_block *sb = fs->super;
70 unsigned long bpg = sb->s_blocks_per_group;
71 unsigned int gdpb = fs->blocksize / sizeof(struct ext2_group_desc);
72 unsigned long max_blocks = 0xffffffff;
73 unsigned long rsv_groups;
74 int rsv_gdb;
75
76 /* We set it at 1024x the current filesystem size, or
77 * the upper block count limit (2^32), whichever is lower.
78 */
79 if (sb->s_blocks_count < max_blocks / 1024)
80 max_blocks = sb->s_blocks_count * 1024;
81 rsv_groups = (max_blocks - sb->s_first_data_block + bpg - 1) / bpg;
82 rsv_gdb = (rsv_groups + gdpb - 1) / gdpb - fs->desc_blocks;
83 if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb))
84 rsv_gdb = EXT2_ADDR_PER_BLOCK(sb);
85#ifdef RES_GDT_DEBUG
86 printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %lu\n",
87 max_blocks, rsv_groups, rsv_gdb);
88#endif
89
90 return rsv_gdb;
91}
92
93errcode_t ext2fs_initialize(const char *name, int flags,
94 struct ext2_super_block *param,
95 io_manager manager, ext2_filsys *ret_fs)
96{
97 ext2_filsys fs;
98 errcode_t retval;
99 struct ext2_super_block *super;
100 int frags_per_block;
101 unsigned int rem;
102 unsigned int overhead = 0;
103 blk_t group_block;
104 unsigned int ipg;
105 dgrp_t i;
106 blk_t numblocks;
107 int rsv_gdt;
108 char *buf;
109
110 if (!param || !param->s_blocks_count)
111 return EXT2_ET_INVALID_ARGUMENT;
112
113 retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs);
114 if (retval)
115 return retval;
116
117 memset(fs, 0, sizeof(struct struct_ext2_filsys));
118 fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
119 fs->flags = flags | EXT2_FLAG_RW;
120 fs->umask = 022;
121#ifdef WORDS_BIGENDIAN
122 fs->flags |= EXT2_FLAG_SWAP_BYTES;
123#endif
124 retval = manager->open(name, IO_FLAG_RW, &fs->io);
125 if (retval)
126 goto cleanup;
127 fs->image_io = fs->io;
128 fs->io->app_data = fs;
129 retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
130 if (retval)
131 goto cleanup;
132
133 strcpy(fs->device_name, name);
134 retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super);
135 if (retval)
136 goto cleanup;
137 fs->super = super;
138
139 memset(super, 0, SUPERBLOCK_SIZE);
140
141#define set_field(field, default) (super->field = param->field ? \
142 param->field : (default))
143
144 super->s_magic = EXT2_SUPER_MAGIC;
145 super->s_state = EXT2_VALID_FS;
146
147 set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */
148 set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */
149 set_field(s_first_data_block, super->s_log_block_size ? 0 : 1);
150 set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT);
151 set_field(s_errors, EXT2_ERRORS_DEFAULT);
152 set_field(s_feature_compat, 0);
153 set_field(s_feature_incompat, 0);
154 set_field(s_feature_ro_compat, 0);
155 set_field(s_first_meta_bg, 0);
156 if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
157 retval = EXT2_ET_UNSUPP_FEATURE;
158 goto cleanup;
159 }
160 if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) {
161 retval = EXT2_ET_RO_UNSUPP_FEATURE;
162 goto cleanup;
163 }
164
165 set_field(s_rev_level, EXT2_GOOD_OLD_REV);
166 if (super->s_rev_level >= EXT2_DYNAMIC_REV) {
167 set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
168 set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE);
169 }
170
171 set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL);
172 super->s_mkfs_time = super->s_lastcheck = time(NULL);
173
174 super->s_creator_os = CREATOR_OS;
175
176 fs->blocksize = EXT2_BLOCK_SIZE(super);
177 fs->fragsize = EXT2_FRAG_SIZE(super);
178 frags_per_block = fs->blocksize / fs->fragsize;
179
180 /* default: (fs->blocksize*8) blocks/group, up to 2^16 (GDT limit) */
181 set_field(s_blocks_per_group, fs->blocksize * 8);
182 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super))
183 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super);
184 super->s_frags_per_group = super->s_blocks_per_group * frags_per_block;
185
186 super->s_blocks_count = param->s_blocks_count;
187 super->s_r_blocks_count = param->s_r_blocks_count;
188 if (super->s_r_blocks_count >= param->s_blocks_count) {
189 retval = EXT2_ET_INVALID_ARGUMENT;
190 goto cleanup;
191 }
192
193 /*
194 * If we're creating an external journal device, we don't need
195 * to bother with the rest.
196 */
197 if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
198 fs->group_desc_count = 0;
199 ext2fs_mark_super_dirty(fs);
200 *ret_fs = fs;
201 return 0;
202 }
203
204retry:
205 fs->group_desc_count = (super->s_blocks_count -
206 super->s_first_data_block +
207 EXT2_BLOCKS_PER_GROUP(super) - 1)
208 / EXT2_BLOCKS_PER_GROUP(super);
209 if (fs->group_desc_count == 0) {
210 retval = EXT2_ET_TOOSMALL;
211 goto cleanup;
212 }
213 fs->desc_blocks = (fs->group_desc_count +
214 EXT2_DESC_PER_BLOCK(super) - 1)
215 / EXT2_DESC_PER_BLOCK(super);
216
217 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize;
218 set_field(s_inodes_count, super->s_blocks_count / i);
219
220 /*
221 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
222 * that we have enough inodes for the filesystem(!)
223 */
224 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1)
225 super->s_inodes_count = EXT2_FIRST_INODE(super)+1;
226
227 /*
228 * There should be at least as many inodes as the user
229 * requested. Figure out how many inodes per group that
230 * should be. But make sure that we don't allocate more than
231 * one bitmap's worth of inodes each group.
232 */
233 ipg = (super->s_inodes_count + fs->group_desc_count - 1) /
234 fs->group_desc_count;
235 if (ipg > fs->blocksize * 8) {
236 if (super->s_blocks_per_group >= 256) {
237 /* Try again with slightly different parameters */
238 super->s_blocks_per_group -= 8;
239 super->s_blocks_count = param->s_blocks_count;
240 super->s_frags_per_group = super->s_blocks_per_group *
241 frags_per_block;
242 goto retry;
243 } else
244 return EXT2_ET_TOO_MANY_INODES;
245 }
246
247 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super))
248 ipg = EXT2_MAX_INODES_PER_GROUP(super);
249
250 super->s_inodes_per_group = ipg;
251 if (super->s_inodes_count > ipg * fs->group_desc_count)
252 super->s_inodes_count = ipg * fs->group_desc_count;
253
254 /*
255 * Make sure the number of inodes per group completely fills
256 * the inode table blocks in the descriptor. If not, add some
257 * additional inodes/group. Waste not, want not...
258 */
259 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
260 EXT2_INODE_SIZE(super)) +
261 EXT2_BLOCK_SIZE(super) - 1) /
262 EXT2_BLOCK_SIZE(super));
263 super->s_inodes_per_group = ((fs->inode_blocks_per_group *
264 EXT2_BLOCK_SIZE(super)) /
265 EXT2_INODE_SIZE(super));
266 /*
267 * Finally, make sure the number of inodes per group is a
268 * multiple of 8. This is needed to simplify the bitmap
269 * splicing code.
270 */
271 super->s_inodes_per_group &= ~7;
272 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
273 EXT2_INODE_SIZE(super)) +
274 EXT2_BLOCK_SIZE(super) - 1) /
275 EXT2_BLOCK_SIZE(super));
276
277 /*
278 * adjust inode count to reflect the adjusted inodes_per_group
279 */
280 super->s_inodes_count = super->s_inodes_per_group *
281 fs->group_desc_count;
282 super->s_free_inodes_count = super->s_inodes_count;
283
284 /*
285 * check the number of reserved group descriptor table blocks
286 */
287 if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE)
288 rsv_gdt = calc_reserved_gdt_blocks(fs);
289 else
290 rsv_gdt = 0;
291 set_field(s_reserved_gdt_blocks, rsv_gdt);
292 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) {
293 retval = EXT2_ET_RES_GDT_BLOCKS;
294 goto cleanup;
295 }
296
297 /*
298 * Overhead is the number of bookkeeping blocks per group. It
299 * includes the superblock backup, the group descriptor
300 * backups, the inode bitmap, the block bitmap, and the inode
301 * table.
302 */
303
304 overhead = (int) (2 + fs->inode_blocks_per_group);
305
306 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
307 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
308
309 /* This can only happen if the user requested too many inodes */
310 if (overhead > super->s_blocks_per_group)
311 return EXT2_ET_TOO_MANY_INODES;
312
313 /*
314 * See if the last group is big enough to support the
315 * necessary data structures. If not, we need to get rid of
316 * it.
317 */
318 rem = ((super->s_blocks_count - super->s_first_data_block) %
319 super->s_blocks_per_group);
320 if ((fs->group_desc_count == 1) && rem && (rem < overhead))
321 return EXT2_ET_TOOSMALL;
322 if (rem && (rem < overhead+50)) {
323 super->s_blocks_count -= rem;
324 goto retry;
325 }
326
327 /*
328 * At this point we know how big the filesystem will be. So
329 * we can do any and all allocations that depend on the block
330 * count.
331 */
332
333 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
334 if (retval)
335 goto cleanup;
336
337 sprintf(buf, "block bitmap for %s", fs->device_name);
338 retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
339 if (retval)
340 goto cleanup;
341
342 sprintf(buf, "inode bitmap for %s", fs->device_name);
343 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
344 if (retval)
345 goto cleanup;
346
347 ext2fs_free_mem(&buf);
348
349 retval = ext2fs_get_mem((size_t) fs->desc_blocks * fs->blocksize,
350 &fs->group_desc);
351 if (retval)
352 goto cleanup;
353
354 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize);
355
356 /*
357 * Reserve the superblock and group descriptors for each
358 * group, and fill in the correct group statistics for group.
359 * Note that although the block bitmap, inode bitmap, and
360 * inode table have not been allocated (and in fact won't be
361 * by this routine), they are accounted for nevertheless.
362 */
363 group_block = super->s_first_data_block;
364 super->s_free_blocks_count = 0;
365 for (i = 0; i < fs->group_desc_count; i++) {
366 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
367
368 super->s_free_blocks_count += numblocks;
369 fs->group_desc[i].bg_free_blocks_count = numblocks;
370 fs->group_desc[i].bg_free_inodes_count =
371 fs->super->s_inodes_per_group;
372 fs->group_desc[i].bg_used_dirs_count = 0;
373
374 group_block += super->s_blocks_per_group;
375 }
376
377 ext2fs_mark_super_dirty(fs);
378 ext2fs_mark_bb_dirty(fs);
379 ext2fs_mark_ib_dirty(fs);
380
381 io_channel_set_blksize(fs->io, fs->blocksize);
382
383 *ret_fs = fs;
384 return 0;
385cleanup:
386 ext2fs_free(fs);
387 return retval;
388}
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