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  • Committer: Bazaar Package Importer
  • Author(s): Guido Guenther
  • Date: 2004-03-02 12:01:14 UTC
  • Revision ID: james.westby@ubuntu.com-20040302120114-0pukal9hlpt3k0l7
Tags: 0.3.8.1
correct subarch detection for IP32

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e2fslib/initialize.c
 
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
#elif defined(__GNU__)     &&   defined(EXT2_OS_HURD)
 
33
#define CREATOR_OS EXT2_OS_HURD
 
34
#elif defined(__FreeBSD__) &&   defined(EXT2_OS_FREEBSD)
 
35
#define CREATOR_OS EXT2_OS_FREEBSD
 
36
#elif defined(LITES)       &&   defined(EXT2_OS_LITES)
 
37
#define CREATOR_OS EXT2_OS_LITES
 
38
#else
 
39
#define CREATOR_OS EXT2_OS_LINUX /* by default */
 
40
#endif
 
41
 
 
42
/*
 
43
 * Note we override the kernel include file's idea of what the default
 
44
 * check interval (never) should be.  It's a good idea to check at
 
45
 * least *occasionally*, specially since servers will never rarely get
 
46
 * to reboot, since Linux is so robust these days.  :-)
 
47
 * 
 
48
 * 180 days (six months) seems like a good value.
 
49
 */
 
50
#ifdef EXT2_DFL_CHECKINTERVAL
 
51
#undef EXT2_DFL_CHECKINTERVAL
 
52
#endif
 
53
#define EXT2_DFL_CHECKINTERVAL (86400L * 180L)
 
54
 
 
55
errcode_t ext2fs_initialize(const char *name, int flags,
 
56
                            struct ext2_super_block *param,
 
57
                            io_manager manager, ext2_filsys *ret_fs)
 
58
{
 
59
        ext2_filsys     fs;
 
60
        errcode_t       retval;
 
61
        struct ext2_super_block *super;
 
62
        int             frags_per_block;
 
63
        int             rem;
 
64
        int             overhead = 0;
 
65
        blk_t           group_block;
 
66
        int             i, j;
 
67
        blk_t           numblocks;
 
68
        char            *buf;
 
69
 
 
70
        if (!param || !param->s_blocks_count)
 
71
                return EXT2_ET_INVALID_ARGUMENT;
 
72
        
 
73
        retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys),
 
74
                                (void **) &fs);
 
75
        if (retval)
 
76
                return retval;
 
77
        
 
78
        memset(fs, 0, sizeof(struct struct_ext2_filsys));
 
79
        fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
 
80
        fs->flags = flags | EXT2_FLAG_RW;
 
81
#ifdef WORDS_BIGENDIAN
 
82
        fs->flags |= EXT2_FLAG_SWAP_BYTES;
 
83
#endif
 
84
        retval = manager->open(name, IO_FLAG_RW, &fs->io);
 
85
        if (retval)
 
86
                goto cleanup;
 
87
        fs->io->app_data = fs;
 
88
        retval = ext2fs_get_mem(strlen(name)+1, (void **) &fs->device_name);
 
89
        if (retval)
 
90
                goto cleanup;
 
91
 
 
92
        strcpy(fs->device_name, name);
 
93
        retval = ext2fs_get_mem(SUPERBLOCK_SIZE, (void **) &super);
 
94
        if (retval)
 
95
                goto cleanup;
 
96
        fs->super = super;
 
97
 
 
98
        memset(super, 0, SUPERBLOCK_SIZE);
 
99
 
 
100
#define set_field(field, default) (super->field = param->field ? \
 
101
                                   param->field : (default))
 
102
 
 
103
        super->s_magic = EXT2_SUPER_MAGIC;
 
104
        super->s_state = EXT2_VALID_FS;
 
105
 
 
106
        set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */
 
107
        set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */
 
108
        set_field(s_first_data_block, super->s_log_block_size ? 0 : 1);
 
109
        set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT);
 
110
        set_field(s_errors, EXT2_ERRORS_DEFAULT);
 
111
        set_field(s_feature_compat, 0);
 
112
        set_field(s_feature_incompat, 0);
 
113
        set_field(s_feature_ro_compat, 0);
 
114
        if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP)
 
115
                return EXT2_ET_UNSUPP_FEATURE;
 
116
        if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP)
 
117
                return EXT2_ET_RO_UNSUPP_FEATURE;
 
118
 
 
119
        set_field(s_rev_level, EXT2_GOOD_OLD_REV);
 
120
        if (super->s_rev_level >= EXT2_DYNAMIC_REV) {
 
121
                set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
 
122
                set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE);
 
123
        }
 
124
 
 
125
        set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL);
 
126
        super->s_lastcheck = time(NULL);
 
127
 
 
128
        super->s_creator_os = CREATOR_OS;
 
129
 
 
130
        fs->blocksize = EXT2_BLOCK_SIZE(super);
 
131
        fs->fragsize = EXT2_FRAG_SIZE(super);
 
132
        frags_per_block = fs->blocksize / fs->fragsize;
 
133
        
 
134
        /* default: (fs->blocksize*8) blocks/group */
 
135
        set_field(s_blocks_per_group, fs->blocksize*8); 
 
136
        super->s_frags_per_group = super->s_blocks_per_group * frags_per_block;
 
137
        
 
138
        super->s_blocks_count = param->s_blocks_count;
 
139
        super->s_r_blocks_count = param->s_r_blocks_count;
 
140
        if (super->s_r_blocks_count >= param->s_blocks_count) {
 
141
                retval = EXT2_ET_INVALID_ARGUMENT;
 
142
                goto cleanup;
 
143
        }
 
144
 
 
145
        /*
 
146
         * If we're creating an external journal device, we don't need
 
147
         * to bother with the rest.
 
148
         */
 
149
        if (super->s_feature_incompat &
 
150
            EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
 
151
                fs->group_desc_count = 0;
 
152
                ext2fs_mark_super_dirty(fs);
 
153
                *ret_fs = fs;
 
154
                return 0;
 
155
        }
 
156
 
 
157
retry:
 
158
        fs->group_desc_count = (super->s_blocks_count -
 
159
                                super->s_first_data_block +
 
160
                                EXT2_BLOCKS_PER_GROUP(super) - 1)
 
161
                / EXT2_BLOCKS_PER_GROUP(super);
 
162
        if (fs->group_desc_count == 0)
 
163
                return EXT2_ET_TOOSMALL;
 
164
        fs->desc_blocks = (fs->group_desc_count +
 
165
                           EXT2_DESC_PER_BLOCK(super) - 1)
 
166
                / EXT2_DESC_PER_BLOCK(super);
 
167
 
 
168
        /* n.b., fs->blocksize is <= 4096 */
 
169
        set_field(s_inodes_count, super->s_blocks_count/(4096/fs->blocksize));
 
170
 
 
171
        /*
 
172
         * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
 
173
         * that we have enough inodes for the filesystem(!)
 
174
         */
 
175
        if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1)
 
176
                super->s_inodes_count = EXT2_FIRST_INODE(super)+1;
 
177
        
 
178
        /*
 
179
         * There should be at least as many inodes as the user
 
180
         * requested.  Figure out how many inodes per group that
 
181
         * should be.  But make sure that we don't allocate more than
 
182
         * one bitmap's worth of inodes
 
183
         */
 
184
        super->s_inodes_per_group = (super->s_inodes_count +
 
185
                                     fs->group_desc_count - 1) /
 
186
                                             fs->group_desc_count;
 
187
        if (super->s_inodes_per_group > fs->blocksize*8)
 
188
                super->s_inodes_per_group = fs->blocksize*8;
 
189
        
 
190
        /*
 
191
         * Make sure the number of inodes per group completely fills
 
192
         * the inode table blocks in the descriptor.  If not, add some
 
193
         * additional inodes/group.  Waste not, want not...
 
194
         */
 
195
        fs->inode_blocks_per_group = (((super->s_inodes_per_group *
 
196
                                        EXT2_INODE_SIZE(super)) +
 
197
                                       EXT2_BLOCK_SIZE(super) - 1) /
 
198
                                      EXT2_BLOCK_SIZE(super));
 
199
        super->s_inodes_per_group = ((fs->inode_blocks_per_group *
 
200
                                      EXT2_BLOCK_SIZE(super)) /
 
201
                                     EXT2_INODE_SIZE(super));
 
202
        /*
 
203
         * Finally, make sure the number of inodes per group is a
 
204
         * multiple of 8.  This is needed to simplify the bitmap
 
205
         * splicing code.
 
206
         */
 
207
        super->s_inodes_per_group &= ~7;
 
208
        fs->inode_blocks_per_group = (((super->s_inodes_per_group *
 
209
                                        EXT2_INODE_SIZE(super)) +
 
210
                                       EXT2_BLOCK_SIZE(super) - 1) /
 
211
                                      EXT2_BLOCK_SIZE(super));
 
212
 
 
213
        /*
 
214
         * adjust inode count to reflect the adjusted inodes_per_group
 
215
         */
 
216
        super->s_inodes_count = super->s_inodes_per_group *
 
217
                fs->group_desc_count;
 
218
        super->s_free_inodes_count = super->s_inodes_count;
 
219
 
 
220
        /*
 
221
         * Overhead is the number of bookkeeping blocks per group.  It
 
222
         * includes the superblock backup, the group descriptor
 
223
         * backups, the inode bitmap, the block bitmap, and the inode
 
224
         * table.
 
225
         *
 
226
         * XXX Not all block groups need the descriptor blocks, but
 
227
         * being clever is tricky...
 
228
         */
 
229
        overhead = (int) (3 + fs->desc_blocks + fs->inode_blocks_per_group);
 
230
        
 
231
        /*
 
232
         * See if the last group is big enough to support the
 
233
         * necessary data structures.  If not, we need to get rid of
 
234
         * it.
 
235
         */
 
236
        rem = (int) ((super->s_blocks_count - super->s_first_data_block) %
 
237
                     super->s_blocks_per_group);
 
238
        if ((fs->group_desc_count == 1) && rem && (rem < overhead))
 
239
                return EXT2_ET_TOOSMALL;
 
240
        if (rem && (rem < overhead+50)) {
 
241
                super->s_blocks_count -= rem;
 
242
                goto retry;
 
243
        }
 
244
 
 
245
        /*
 
246
         * At this point we know how big the filesystem will be.  So
 
247
         * we can do any and all allocations that depend on the block
 
248
         * count.
 
249
         */
 
250
 
 
251
        retval = ext2fs_get_mem(strlen(fs->device_name) + 80,
 
252
                                (void **) &buf);
 
253
        if (retval)
 
254
                goto cleanup;
 
255
        
 
256
        sprintf(buf, "block bitmap for %s", fs->device_name);
 
257
        retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
 
258
        if (retval)
 
259
                goto cleanup;
 
260
        
 
261
        sprintf(buf, "inode bitmap for %s", fs->device_name);
 
262
        retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
 
263
        if (retval)
 
264
                goto cleanup;
 
265
 
 
266
        ext2fs_free_mem((void **) &buf);
 
267
 
 
268
        retval = ext2fs_get_mem((size_t) fs->desc_blocks * fs->blocksize,
 
269
                                (void **) &fs->group_desc);
 
270
        if (retval)
 
271
                goto cleanup;
 
272
 
 
273
        memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize);
 
274
 
 
275
        /*
 
276
         * Reserve the superblock and group descriptors for each
 
277
         * group, and fill in the correct group statistics for group.
 
278
         * Note that although the block bitmap, inode bitmap, and
 
279
         * inode table have not been allocated (and in fact won't be
 
280
         * by this routine), they are accounted for nevertheless.
 
281
         */
 
282
        group_block = super->s_first_data_block;
 
283
        super->s_free_blocks_count = 0;
 
284
        for (i = 0; i < fs->group_desc_count; i++) {
 
285
                if (i == fs->group_desc_count-1) {
 
286
                        numblocks = (fs->super->s_blocks_count -
 
287
                                     fs->super->s_first_data_block) %
 
288
                                             fs->super->s_blocks_per_group;
 
289
                        if (!numblocks)
 
290
                                numblocks = fs->super->s_blocks_per_group;
 
291
                } else
 
292
                        numblocks = fs->super->s_blocks_per_group;
 
293
 
 
294
                if (ext2fs_bg_has_super(fs, i)) {
 
295
                        for (j=0; j < fs->desc_blocks+1; j++)
 
296
                                ext2fs_mark_block_bitmap(fs->block_map,
 
297
                                                         group_block + j);
 
298
                        numblocks -= 1 + fs->desc_blocks;
 
299
                }
 
300
                
 
301
                numblocks -= 2 + fs->inode_blocks_per_group;
 
302
                
 
303
                super->s_free_blocks_count += numblocks;
 
304
                fs->group_desc[i].bg_free_blocks_count = numblocks;
 
305
                fs->group_desc[i].bg_free_inodes_count =
 
306
                        fs->super->s_inodes_per_group;
 
307
                fs->group_desc[i].bg_used_dirs_count = 0;
 
308
                
 
309
                group_block += super->s_blocks_per_group;
 
310
        }
 
311
        
 
312
        ext2fs_mark_super_dirty(fs);
 
313
        ext2fs_mark_bb_dirty(fs);
 
314
        ext2fs_mark_ib_dirty(fs);
 
315
        
 
316
        io_channel_set_blksize(fs->io, fs->blocksize);
 
317
 
 
318
        *ret_fs = fs;
 
319
        return 0;
 
320
cleanup:
 
321
        ext2fs_free(fs);
 
322
        return retval;
 
323
}
 
324
        
 
325
 
 
326