2 * initialize.c --- initialize a filesystem handle given superblock
3 * parameters. Used by mke2fs when initializing a filesystem.
5 * Copyright (C) 1994, 1995, 1996 Theodore Ts'o.
8 * This file may be redistributed under the terms of the GNU Public
24 #include <sys/types.h>
30 #if defined(__linux__) && defined(EXT2_OS_LINUX)
31 #define CREATOR_OS EXT2_OS_LINUX
33 #if defined(__GNU__) && defined(EXT2_OS_HURD)
34 #define CREATOR_OS EXT2_OS_HURD
36 #if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD)
37 #define CREATOR_OS EXT2_OS_FREEBSD
39 #if defined(LITES) && defined(EXT2_OS_LITES)
40 #define CREATOR_OS EXT2_OS_LITES
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) */
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. :-)
54 * 180 days (six months) seems like a good value.
56 #ifdef EXT2_DFL_CHECKINTERVAL
57 #undef EXT2_DFL_CHECKINTERVAL
59 #define EXT2_DFL_CHECKINTERVAL (86400L * 180L)
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.
66 static unsigned int calc_reserved_gdt_blocks(ext2_filsys fs)
68 struct ext2_super_block *sb = fs->super;
69 unsigned long bpg = sb->s_blocks_per_group;
70 unsigned int gdpb = EXT2_DESC_PER_BLOCK(sb);
71 unsigned long max_blocks = 0xffffffff;
72 unsigned long rsv_groups;
75 /* We set it at 1024x the current filesystem size, or
76 * the upper block count limit (2^32), whichever is lower.
78 if (sb->s_blocks_count < max_blocks / 1024)
79 max_blocks = sb->s_blocks_count * 1024;
80 rsv_groups = ext2fs_div_ceil(max_blocks - sb->s_first_data_block, bpg);
81 rsv_gdb = ext2fs_div_ceil(rsv_groups, gdpb) - fs->desc_blocks;
82 if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb))
83 rsv_gdb = EXT2_ADDR_PER_BLOCK(sb);
85 printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %u\n",
86 max_blocks, rsv_groups, rsv_gdb);
92 errcode_t ext2fs_initialize(const char *name, int flags,
93 struct ext2_super_block *param,
94 io_manager manager, ext2_filsys *ret_fs)
98 struct ext2_super_block *super;
101 unsigned int overhead = 0;
110 if (!param || !param->s_blocks_count)
111 return EXT2_ET_INVALID_ARGUMENT;
113 retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs);
117 memset(fs, 0, sizeof(struct struct_ext2_filsys));
118 fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
119 fs->flags = flags | EXT2_FLAG_RW;
121 #ifdef WORDS_BIGENDIAN
122 fs->flags |= EXT2_FLAG_SWAP_BYTES;
124 io_flags = IO_FLAG_RW;
125 if (flags & EXT2_FLAG_EXCLUSIVE)
126 io_flags |= IO_FLAG_EXCLUSIVE;
127 retval = manager->open(name, io_flags, &fs->io);
130 fs->image_io = fs->io;
131 fs->io->app_data = fs;
132 retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
136 strcpy(fs->device_name, name);
137 retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super);
142 memset(super, 0, SUPERBLOCK_SIZE);
144 #define set_field(field, default) (super->field = param->field ? \
145 param->field : (default))
147 super->s_magic = EXT2_SUPER_MAGIC;
148 super->s_state = EXT2_VALID_FS;
150 set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */
151 set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */
152 set_field(s_first_data_block, super->s_log_block_size ? 0 : 1);
153 set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT);
154 set_field(s_errors, EXT2_ERRORS_DEFAULT);
155 set_field(s_feature_compat, 0);
156 set_field(s_feature_incompat, 0);
157 set_field(s_feature_ro_compat, 0);
158 set_field(s_first_meta_bg, 0);
159 set_field(s_raid_stride, 0); /* default stride size: 0 */
160 set_field(s_raid_stripe_width, 0); /* default stripe width: 0 */
161 set_field(s_flags, 0);
162 if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
163 retval = EXT2_ET_UNSUPP_FEATURE;
166 if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) {
167 retval = EXT2_ET_RO_UNSUPP_FEATURE;
171 set_field(s_rev_level, EXT2_GOOD_OLD_REV);
172 if (super->s_rev_level >= EXT2_DYNAMIC_REV) {
173 set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
174 set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE);
175 if (super->s_inode_size >= sizeof(struct ext2_inode_large)) {
176 int extra_isize = sizeof(struct ext2_inode_large) -
177 EXT2_GOOD_OLD_INODE_SIZE;
178 set_field(s_min_extra_isize, extra_isize);
179 set_field(s_want_extra_isize, extra_isize);
183 set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL);
184 super->s_mkfs_time = super->s_lastcheck = fs->now ? fs->now : time(NULL);
186 super->s_creator_os = CREATOR_OS;
188 fs->blocksize = EXT2_BLOCK_SIZE(super);
189 fs->fragsize = EXT2_FRAG_SIZE(super);
190 frags_per_block = fs->blocksize / fs->fragsize;
192 /* default: (fs->blocksize*8) blocks/group, up to 2^16 (GDT limit) */
193 set_field(s_blocks_per_group, fs->blocksize * 8);
194 if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super))
195 super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super);
196 super->s_frags_per_group = super->s_blocks_per_group * frags_per_block;
198 super->s_blocks_count = param->s_blocks_count;
199 super->s_r_blocks_count = param->s_r_blocks_count;
200 if (super->s_r_blocks_count >= param->s_blocks_count) {
201 retval = EXT2_ET_INVALID_ARGUMENT;
206 * If we're creating an external journal device, we don't need
207 * to bother with the rest.
209 if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
210 fs->group_desc_count = 0;
211 ext2fs_mark_super_dirty(fs);
217 fs->group_desc_count = ext2fs_div_ceil(super->s_blocks_count -
218 super->s_first_data_block,
219 EXT2_BLOCKS_PER_GROUP(super));
220 if (fs->group_desc_count == 0) {
221 retval = EXT2_ET_TOOSMALL;
224 fs->desc_blocks = ext2fs_div_ceil(fs->group_desc_count,
225 EXT2_DESC_PER_BLOCK(super));
227 i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize;
228 set_field(s_inodes_count, super->s_blocks_count / i);
231 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
232 * that we have enough inodes for the filesystem(!)
234 if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1)
235 super->s_inodes_count = EXT2_FIRST_INODE(super)+1;
238 * There should be at least as many inodes as the user
239 * requested. Figure out how many inodes per group that
240 * should be. But make sure that we don't allocate more than
241 * one bitmap's worth of inodes each group.
243 ipg = ext2fs_div_ceil(super->s_inodes_count, fs->group_desc_count);
244 if (ipg > fs->blocksize * 8) {
245 if (super->s_blocks_per_group >= 256) {
246 /* Try again with slightly different parameters */
247 super->s_blocks_per_group -= 8;
248 super->s_blocks_count = param->s_blocks_count;
249 super->s_frags_per_group = super->s_blocks_per_group *
253 return EXT2_ET_TOO_MANY_INODES;
256 if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super))
257 ipg = EXT2_MAX_INODES_PER_GROUP(super);
260 super->s_inodes_per_group = ipg;
263 * Make sure the number of inodes per group completely fills
264 * the inode table blocks in the descriptor. If not, add some
265 * additional inodes/group. Waste not, want not...
267 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
268 EXT2_INODE_SIZE(super)) +
269 EXT2_BLOCK_SIZE(super) - 1) /
270 EXT2_BLOCK_SIZE(super));
271 super->s_inodes_per_group = ((fs->inode_blocks_per_group *
272 EXT2_BLOCK_SIZE(super)) /
273 EXT2_INODE_SIZE(super));
275 * Finally, make sure the number of inodes per group is a
276 * multiple of 8. This is needed to simplify the bitmap
279 super->s_inodes_per_group &= ~7;
280 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
281 EXT2_INODE_SIZE(super)) +
282 EXT2_BLOCK_SIZE(super) - 1) /
283 EXT2_BLOCK_SIZE(super));
286 * adjust inode count to reflect the adjusted inodes_per_group
288 if ((__u64)super->s_inodes_per_group * fs->group_desc_count > ~0U) {
292 super->s_inodes_count = super->s_inodes_per_group *
293 fs->group_desc_count;
294 super->s_free_inodes_count = super->s_inodes_count;
297 * check the number of reserved group descriptor table blocks
299 if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE)
300 rsv_gdt = calc_reserved_gdt_blocks(fs);
303 set_field(s_reserved_gdt_blocks, rsv_gdt);
304 if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) {
305 retval = EXT2_ET_RES_GDT_BLOCKS;
310 * Calculate the maximum number of bookkeeping blocks per
311 * group. It includes the superblock, the block group
312 * descriptors, the block bitmap, the inode bitmap, the inode
313 * table, and the reserved gdt blocks.
315 overhead = (int) (3 + fs->inode_blocks_per_group +
316 fs->desc_blocks + super->s_reserved_gdt_blocks);
318 /* This can only happen if the user requested too many inodes */
319 if (overhead > super->s_blocks_per_group)
320 return EXT2_ET_TOO_MANY_INODES;
323 * See if the last group is big enough to support the
324 * necessary data structures. If not, we need to get rid of
325 * it. We need to recalculate the overhead for the last block
326 * group, since it might or might not have a superblock
329 overhead = (int) (2 + fs->inode_blocks_per_group);
330 if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
331 overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
332 rem = ((super->s_blocks_count - super->s_first_data_block) %
333 super->s_blocks_per_group);
334 if ((fs->group_desc_count == 1) && rem && (rem < overhead))
335 return EXT2_ET_TOOSMALL;
336 if (rem && (rem < overhead+50)) {
337 super->s_blocks_count -= rem;
342 * At this point we know how big the filesystem will be. So
343 * we can do any and all allocations that depend on the block
347 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
351 sprintf(buf, "block bitmap for %s", fs->device_name);
352 retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
356 sprintf(buf, "inode bitmap for %s", fs->device_name);
357 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
361 ext2fs_free_mem(&buf);
363 retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize,
368 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize);
371 * Reserve the superblock and group descriptors for each
372 * group, and fill in the correct group statistics for group.
373 * Note that although the block bitmap, inode bitmap, and
374 * inode table have not been allocated (and in fact won't be
375 * by this routine), they are accounted for nevertheless.
377 super->s_free_blocks_count = 0;
378 for (i = 0; i < fs->group_desc_count; i++) {
379 numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
381 super->s_free_blocks_count += numblocks;
382 fs->group_desc[i].bg_free_blocks_count = numblocks;
383 fs->group_desc[i].bg_free_inodes_count =
384 fs->super->s_inodes_per_group;
385 fs->group_desc[i].bg_used_dirs_count = 0;
386 ext2fs_group_desc_csum_set(fs, i);
390 if (((int) c) == -1) {
391 super->s_flags |= EXT2_FLAGS_SIGNED_HASH;
393 super->s_flags |= EXT2_FLAGS_UNSIGNED_HASH;
396 ext2fs_mark_super_dirty(fs);
397 ext2fs_mark_bb_dirty(fs);
398 ext2fs_mark_ib_dirty(fs);
400 io_channel_set_blksize(fs->io, fs->blocksize);