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>
27 #if EXT2_FLAT_INCLUDES
30 #include <linux/ext2_fs.h>
35 #if defined(__linux__) && defined(EXT2_OS_LINUX)
36 #define CREATOR_OS EXT2_OS_LINUX
37 #elif defined(__gnu__) && defined(EXT2_OS_HURD)
38 #define CREATOR_OS EXT2_OS_HURD
39 #elif defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD)
40 #define CREATOR_OS EXT2_OS_FREEBSD
41 #elif defined(LITES) && defined(EXT2_OS_LITES)
42 #define CREATOR_OS EXT2_OS_LITES
44 #define CREATOR_OS EXT2_OS_LINUX /* by default */
48 * Note we override the kernel include file's idea of what the default
49 * check interval (never) should be. It's a good idea to check at
50 * least *occasionally*, specially since servers will never rarely get
51 * to reboot, since Linux is so robust these days. :-)
53 * 180 days (six months) seems like a good value.
55 #ifdef EXT2_DFL_CHECKINTERVAL
56 #undef EXT2_DFL_CHECKINTERVAL
58 #define EXT2_DFL_CHECKINTERVAL (86400L * 180L)
60 errcode_t ext2fs_initialize(const char *name, int flags,
61 struct ext2_super_block *param,
62 io_manager manager, ext2_filsys *ret_fs)
66 struct ext2_super_block *super;
75 if (!param || !param->s_blocks_count)
76 return EXT2_ET_INVALID_ARGUMENT;
78 retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys),
83 memset(fs, 0, sizeof(struct struct_ext2_filsys));
84 fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
85 fs->flags = flags | EXT2_FLAG_RW | ext2fs_native_flag();
86 retval = manager->open(name, IO_FLAG_RW, &fs->io);
89 fs->io->app_data = fs;
90 retval = ext2fs_get_mem(strlen(name)+1, (void **) &fs->device_name);
94 strcpy(fs->device_name, name);
95 retval = ext2fs_get_mem(SUPERBLOCK_SIZE, (void **) &super);
100 memset(super, 0, SUPERBLOCK_SIZE);
102 #define set_field(field, default) (super->field = param->field ? \
103 param->field : (default))
105 super->s_magic = EXT2_SUPER_MAGIC;
106 super->s_state = EXT2_VALID_FS;
108 set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */
109 set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */
110 set_field(s_first_data_block, super->s_log_block_size ? 0 : 1);
111 set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT);
112 set_field(s_errors, EXT2_ERRORS_DEFAULT);
113 #ifdef EXT2_DYNAMIC_REV
114 set_field(s_feature_compat, 0);
115 set_field(s_feature_incompat, 0);
116 set_field(s_feature_ro_compat, 0);
117 if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP)
118 return EXT2_ET_UNSUPP_FEATURE;
119 if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP)
120 return EXT2_ET_RO_UNSUPP_FEATURE;
122 set_field(s_rev_level, EXT2_GOOD_OLD_REV);
123 if (super->s_rev_level >= EXT2_DYNAMIC_REV) {
124 set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
125 set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE);
129 set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL);
130 super->s_lastcheck = time(NULL);
132 super->s_creator_os = CREATOR_OS;
134 fs->blocksize = EXT2_BLOCK_SIZE(super);
135 fs->fragsize = EXT2_FRAG_SIZE(super);
136 frags_per_block = fs->blocksize / fs->fragsize;
138 /* default: (fs->blocksize*8) blocks/group */
139 set_field(s_blocks_per_group, fs->blocksize*8);
140 super->s_frags_per_group = super->s_blocks_per_group * frags_per_block;
142 super->s_blocks_count = param->s_blocks_count;
143 super->s_r_blocks_count = param->s_r_blocks_count;
144 if (super->s_r_blocks_count >= param->s_blocks_count) {
145 retval = EXT2_ET_INVALID_ARGUMENT;
150 fs->group_desc_count = (super->s_blocks_count -
151 super->s_first_data_block +
152 EXT2_BLOCKS_PER_GROUP(super) - 1)
153 / EXT2_BLOCKS_PER_GROUP(super);
154 if (fs->group_desc_count == 0)
155 return EXT2_ET_TOOSMALL;
156 fs->desc_blocks = (fs->group_desc_count +
157 EXT2_DESC_PER_BLOCK(super) - 1)
158 / EXT2_DESC_PER_BLOCK(super);
160 /* n.b., fs->blocksize is <= 4096 */
161 set_field(s_inodes_count, super->s_blocks_count/(4096/fs->blocksize));
164 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
165 * that we have enough inodes for the filesystem(!)
167 if (super->s_inodes_count < EXT2_FIRST_INO(super)+1)
168 super->s_inodes_count = EXT2_FIRST_INO(super)+1;
171 * There should be at least as many inodes as the user
172 * requested. Figure out how many inodes per group that
173 * should be. But make sure that we don't allocate more than
174 * one bitmap's worth of inodes
176 super->s_inodes_per_group = (super->s_inodes_count +
177 fs->group_desc_count - 1) /
178 fs->group_desc_count;
179 if (super->s_inodes_per_group > fs->blocksize*8)
180 super->s_inodes_per_group = fs->blocksize*8;
183 * Make sure the number of inodes per group completely fills
184 * the inode table blocks in the descriptor. If not, add some
185 * additional inodes/group. Waste not, want not...
187 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
188 EXT2_INODE_SIZE(super)) +
189 EXT2_BLOCK_SIZE(super) - 1) /
190 EXT2_BLOCK_SIZE(super));
191 super->s_inodes_per_group = ((fs->inode_blocks_per_group *
192 EXT2_BLOCK_SIZE(super)) /
193 EXT2_INODE_SIZE(super));
195 * Finally, make sure the number of inodes per group is a
196 * multiple of 8. This is needed to simplify the bitmap
199 super->s_inodes_per_group &= ~7;
200 fs->inode_blocks_per_group = (((super->s_inodes_per_group *
201 EXT2_INODE_SIZE(super)) +
202 EXT2_BLOCK_SIZE(super) - 1) /
203 EXT2_BLOCK_SIZE(super));
206 * adjust inode count to reflect the adjusted inodes_per_group
208 super->s_inodes_count = super->s_inodes_per_group *
209 fs->group_desc_count;
210 super->s_free_inodes_count = super->s_inodes_count;
213 * Overhead is the number of bookkeeping blocks per group. It
214 * includes the superblock backup, the group descriptor
215 * backups, the inode bitmap, the block bitmap, and the inode
218 * XXX Not all block groups need the descriptor blocks, but
219 * being clever is tricky...
221 overhead = (int) (3 + fs->desc_blocks + fs->inode_blocks_per_group);
224 * See if the last group is big enough to support the
225 * necessary data structures. If not, we need to get rid of
228 rem = (int) ((super->s_blocks_count - super->s_first_data_block) %
229 super->s_blocks_per_group);
230 if ((fs->group_desc_count == 1) && rem && (rem < overhead))
231 return EXT2_ET_TOOSMALL;
232 if (rem && (rem < overhead+50)) {
233 super->s_blocks_count -= rem;
238 * At this point we know how big the filesystem will be. So
239 * we can do any and all allocations that depend on the block
243 retval = ext2fs_get_mem(strlen(fs->device_name) + 80,
248 sprintf(buf, "block bitmap for %s", fs->device_name);
249 retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
253 sprintf(buf, "inode bitmap for %s", fs->device_name);
254 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
258 ext2fs_free_mem((void **) &buf);
260 retval = ext2fs_get_mem((size_t) fs->desc_blocks * fs->blocksize,
261 (void **) &fs->group_desc);
265 memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize);
268 * Reserve the superblock and group descriptors for each
269 * group, and fill in the correct group statistics for group.
270 * Note that although the block bitmap, inode bitmap, and
271 * inode table have not been allocated (and in fact won't be
272 * by this routine), they are accounted for nevertheless.
274 group_block = super->s_first_data_block;
275 super->s_free_blocks_count = 0;
276 for (i = 0; i < fs->group_desc_count; i++) {
277 if (i == fs->group_desc_count-1) {
278 numblocks = (fs->super->s_blocks_count -
279 fs->super->s_first_data_block) %
280 fs->super->s_blocks_per_group;
282 numblocks = fs->super->s_blocks_per_group;
284 numblocks = fs->super->s_blocks_per_group;
286 if (ext2fs_bg_has_super(fs, i)) {
287 for (j=0; j < fs->desc_blocks+1; j++)
288 ext2fs_mark_block_bitmap(fs->block_map,
290 numblocks -= 1 + fs->desc_blocks;
293 numblocks -= 2 + fs->inode_blocks_per_group;
295 super->s_free_blocks_count += numblocks;
296 fs->group_desc[i].bg_free_blocks_count = numblocks;
297 fs->group_desc[i].bg_free_inodes_count =
298 fs->super->s_inodes_per_group;
299 fs->group_desc[i].bg_used_dirs_count = 0;
301 group_block += super->s_blocks_per_group;
304 ext2fs_mark_super_dirty(fs);
305 ext2fs_mark_bb_dirty(fs);
306 ext2fs_mark_ib_dirty(fs);
308 io_channel_set_blksize(fs->io, fs->blocksize);