1 /* vi: set sw=4 ts=4: */
3 * initialize.c --- initialize a filesystem handle given superblock
4 * parameters. Used by mke2fs when initializing a filesystem.
6 * Copyright (C) 1994, 1995, 1996 Theodore Ts'o.
9 * This file may be redistributed under the terms of the GNU Public
25 #include <sys/types.h>
31 #if defined(__linux__) && defined(EXT2_OS_LINUX)
32 #define CREATOR_OS EXT2_OS_LINUX
34 #if defined(__GNU__) && defined(EXT2_OS_HURD)
35 #define CREATOR_OS EXT2_OS_HURD
37 #if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD)
38 #define CREATOR_OS EXT2_OS_FREEBSD
40 #if defined(LITES) && defined(EXT2_OS_LITES)
41 #define CREATOR_OS EXT2_OS_LITES
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) */
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. :-)
55 * 180 days (six months) seems like a good value.
57 #ifdef EXT2_DFL_CHECKINTERVAL
58 #undef EXT2_DFL_CHECKINTERVAL
60 #define EXT2_DFL_CHECKINTERVAL (86400L * 180L)
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.
67 static int calc_reserved_gdt_blocks(ext2_filsys fs
)
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
;
76 /* We set it at 1024x the current filesystem size, or
77 * the upper block count limit (2^32), whichever is lower.
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
);
86 printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %lu\n",
87 max_blocks
, rsv_groups
, rsv_gdb
);
93 errcode_t
ext2fs_initialize(const char *name
, int flags
,
94 struct ext2_super_block
*param
,
95 io_manager manager
, ext2_filsys
*ret_fs
)
99 struct ext2_super_block
*super
;
102 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 retval
= manager
->open(name
, IO_FLAG_RW
, &fs
->io
);
127 fs
->image_io
= fs
->io
;
128 fs
->io
->app_data
= fs
;
129 retval
= ext2fs_get_mem(strlen(name
)+1, &fs
->device_name
);
133 strcpy(fs
->device_name
, name
);
134 retval
= ext2fs_get_mem(SUPERBLOCK_SIZE
, &super
);
139 memset(super
, 0, SUPERBLOCK_SIZE
);
141 #define set_field(field, default) (super->field = param->field ? \
142 param->field : (default))
144 super
->s_magic
= EXT2_SUPER_MAGIC
;
145 super
->s_state
= EXT2_VALID_FS
;
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
;
160 if (super
->s_feature_ro_compat
& ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP
) {
161 retval
= EXT2_ET_RO_UNSUPP_FEATURE
;
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
);
171 set_field(s_checkinterval
, EXT2_DFL_CHECKINTERVAL
);
172 super
->s_mkfs_time
= super
->s_lastcheck
= time(NULL
);
174 super
->s_creator_os
= CREATOR_OS
;
176 fs
->blocksize
= EXT2_BLOCK_SIZE(super
);
177 fs
->fragsize
= EXT2_FRAG_SIZE(super
);
178 frags_per_block
= fs
->blocksize
/ fs
->fragsize
;
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
;
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
;
194 * If we're creating an external journal device, we don't need
195 * to bother with the rest.
197 if (super
->s_feature_incompat
& EXT3_FEATURE_INCOMPAT_JOURNAL_DEV
) {
198 fs
->group_desc_count
= 0;
199 ext2fs_mark_super_dirty(fs
);
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
;
213 fs
->desc_blocks
= (fs
->group_desc_count
+
214 EXT2_DESC_PER_BLOCK(super
) - 1)
215 / EXT2_DESC_PER_BLOCK(super
);
217 i
= fs
->blocksize
>= 4096 ? 1 : 4096 / fs
->blocksize
;
218 set_field(s_inodes_count
, super
->s_blocks_count
/ i
);
221 * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
222 * that we have enough inodes for the filesystem(!)
224 if (super
->s_inodes_count
< EXT2_FIRST_INODE(super
)+1)
225 super
->s_inodes_count
= EXT2_FIRST_INODE(super
)+1;
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.
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
*
244 return EXT2_ET_TOO_MANY_INODES
;
247 if (ipg
> (unsigned) EXT2_MAX_INODES_PER_GROUP(super
))
248 ipg
= EXT2_MAX_INODES_PER_GROUP(super
);
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
;
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...
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
));
267 * Finally, make sure the number of inodes per group is a
268 * multiple of 8. This is needed to simplify the bitmap
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
));
278 * adjust inode count to reflect the adjusted inodes_per_group
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
;
285 * check the number of reserved group descriptor table blocks
287 if (super
->s_feature_compat
& EXT2_FEATURE_COMPAT_RESIZE_INODE
)
288 rsv_gdt
= calc_reserved_gdt_blocks(fs
);
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
;
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
304 overhead
= (int) (2 + fs
->inode_blocks_per_group
);
306 if (ext2fs_bg_has_super(fs
, fs
->group_desc_count
- 1))
307 overhead
+= 1 + fs
->desc_blocks
+ super
->s_reserved_gdt_blocks
;
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
;
314 * See if the last group is big enough to support the
315 * necessary data structures. If not, we need to get rid of
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
;
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
333 retval
= ext2fs_get_mem(strlen(fs
->device_name
) + 80, &buf
);
337 sprintf(buf
, "block bitmap for %s", fs
->device_name
);
338 retval
= ext2fs_allocate_block_bitmap(fs
, buf
, &fs
->block_map
);
342 sprintf(buf
, "inode bitmap for %s", fs
->device_name
);
343 retval
= ext2fs_allocate_inode_bitmap(fs
, buf
, &fs
->inode_map
);
347 ext2fs_free_mem(&buf
);
349 retval
= ext2fs_get_mem((size_t) fs
->desc_blocks
* fs
->blocksize
,
354 memset(fs
->group_desc
, 0, (size_t) fs
->desc_blocks
* fs
->blocksize
);
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.
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
);
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;
374 group_block
+= super
->s_blocks_per_group
;
377 ext2fs_mark_super_dirty(fs
);
378 ext2fs_mark_bb_dirty(fs
);
379 ext2fs_mark_ib_dirty(fs
);
381 io_channel_set_blksize(fs
->io
, fs
->blocksize
);