FreeBSD/Linux Kernel Cross Reference
sys/fs/ext2fs/ext2fs.h
1 /*-
2 * modified for EXT2FS support in Lites 1.1
3 *
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
6 *
7 * $FreeBSD: releng/9.1/sys/fs/ext2fs/ext2fs.h 233322 2012-03-22 20:31:52Z pfg $
8 */
9 /*-
10 * Copyright (c) 2009 Aditya Sarawgi
11 * All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *
35 */
36
37 #ifndef _FS_EXT2FS_EXT2FS_H_
38 #define _FS_EXT2FS_EXT2FS_H_
39
40 #include <sys/types.h>
41
42 /*
43 * Maximal count of links to a file
44 */
45 #define EXT2_LINK_MAX 32000
46
47 /*
48 * A summary of contiguous blocks of various sizes is maintained
49 * in each cylinder group. Normally this is set by the initial
50 * value of fs_maxcontig.
51 *
52 * XXX:FS_MAXCONTIG is set to 16 to conserve space. Here we set
53 * EXT2_MAXCONTIG to 32 for better performance.
54 */
55 #define EXT2_MAXCONTIG 32
56
57 /*
58 * Constants relative to the data blocks
59 */
60 #define EXT2_NDIR_BLOCKS 12
61 #define EXT2_IND_BLOCK EXT2_NDIR_BLOCKS
62 #define EXT2_DIND_BLOCK (EXT2_IND_BLOCK + 1)
63 #define EXT2_TIND_BLOCK (EXT2_DIND_BLOCK + 1)
64 #define EXT2_N_BLOCKS (EXT2_TIND_BLOCK + 1)
65 #define EXT2_MAXSYMLINKLEN (EXT2_N_BLOCKS * sizeof(uint32_t))
66
67 /*
68 * The path name on which the file system is mounted is maintained
69 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
70 * the super block for this name.
71 */
72 #define MAXMNTLEN 512
73
74 /*
75 * Super block for an ext2fs file system.
76 */
77 struct ext2fs {
78 uint32_t e2fs_icount; /* Inode count */
79 uint32_t e2fs_bcount; /* blocks count */
80 uint32_t e2fs_rbcount; /* reserved blocks count */
81 uint32_t e2fs_fbcount; /* free blocks count */
82 uint32_t e2fs_ficount; /* free inodes count */
83 uint32_t e2fs_first_dblock; /* first data block */
84 uint32_t e2fs_log_bsize; /* block size = 1024*(2^e2fs_log_bsize) */
85 uint32_t e2fs_log_fsize; /* fragment size */
86 uint32_t e2fs_bpg; /* blocks per group */
87 uint32_t e2fs_fpg; /* frags per group */
88 uint32_t e2fs_ipg; /* inodes per group */
89 uint32_t e2fs_mtime; /* mount time */
90 uint32_t e2fs_wtime; /* write time */
91 uint16_t e2fs_mnt_count; /* mount count */
92 uint16_t e2fs_max_mnt_count; /* max mount count */
93 uint16_t e2fs_magic; /* magic number */
94 uint16_t e2fs_state; /* file system state */
95 uint16_t e2fs_beh; /* behavior on errors */
96 uint16_t e2fs_minrev; /* minor revision level */
97 uint32_t e2fs_lastfsck; /* time of last fsck */
98 uint32_t e2fs_fsckintv; /* max time between fscks */
99 uint32_t e2fs_creator; /* creator OS */
100 uint32_t e2fs_rev; /* revision level */
101 uint16_t e2fs_ruid; /* default uid for reserved blocks */
102 uint16_t e2fs_rgid; /* default gid for reserved blocks */
103 /* EXT2_DYNAMIC_REV superblocks */
104 uint32_t e2fs_first_ino; /* first non-reserved inode */
105 uint16_t e2fs_inode_size; /* size of inode structure */
106 uint16_t e2fs_block_group_nr; /* block grp number of this sblk*/
107 uint32_t e2fs_features_compat; /* compatible feature set */
108 uint32_t e2fs_features_incompat; /* incompatible feature set */
109 uint32_t e2fs_features_rocompat; /* RO-compatible feature set */
110 uint8_t e2fs_uuid[16]; /* 128-bit uuid for volume */
111 char e2fs_vname[16]; /* volume name */
112 char e2fs_fsmnt[64]; /* name mounted on */
113 uint32_t e2fs_algo; /* For compression */
114 uint8_t e2fs_prealloc; /* # of blocks for old prealloc */
115 uint8_t e2fs_dir_prealloc; /* # of blocks for old prealloc dirs */
116 uint16_t e2fs_reserved_ngdb; /* # of reserved gd blocks for resize */
117 char e3fs_journal_uuid[16]; /* uuid of journal superblock */
118 uint32_t e3fs_journal_inum; /* inode number of journal file */
119 uint32_t e3fs_journal_dev; /* device number of journal file */
120 uint32_t e3fs_last_orphan; /* start of list of inodes to delete */
121 uint32_t e3fs_hash_seed[4]; /* HTREE hash seed */
122 char e3fs_def_hash_version; /* Default hash version to use */
123 char e3fs_reserved_char_pad;
124 uint32_t e3fs_default_mount_opts;
125 uint32_t e3fs_first_meta_bg; /* First metablock block group */
126 uint32_t e3fs_mkfs_time; /* when the fs was created */
127 uint32_t e3fs_jnl_blks[17]; /* backup of the journal inode */
128 uint32_t e4fs_bcount_hi; /* block count */
129 uint32_t e4fs_rbcount_hi; /* reserved blocks count */
130 uint32_t e4fs_fbcount_hi; /* free blocks count */
131 uint16_t e4fs_min_extra_isize;/* all inodes have at least some bytes */
132 uint16_t e4fs_want_extra_isize; /* inodes must reserve some bytes */
133 uint32_t e4fs_flags; /* miscellaneous flags */
134 uint16_t e4fs_raid_stride; /* RAID stride */
135 uint16_t e4fs_mmpintv; /* number of seconds to wait in MMP checking */
136 uint64_t e4fs_mmpblk; /* block for multi-mount protection */
137 uint32_t e4fs_raid_stripe_wid;/* blocks on all data disks (N * stride) */
138 uint8_t e4fs_log_gpf; /* FLEX_BG group size */
139 uint8_t e4fs_char_pad2;
140 uint16_t e4fs_pad;
141 uint32_t reserved2[162]; /* Padding to the end of the block */
142 };
143
144
145 /*
146 * In-Memory Superblock
147 */
148
149 struct m_ext2fs {
150 struct ext2fs * e2fs;
151 char e2fs_fsmnt[MAXMNTLEN];/* name mounted on */
152 char e2fs_ronly; /* mounted read-only flag */
153 char e2fs_fmod; /* super block modified flag */
154 uint32_t e2fs_bsize; /* Block size */
155 uint32_t e2fs_bshift; /* calc of logical block no */
156 int32_t e2fs_bmask; /* calc of block offset */
157 int32_t e2fs_bpg; /* Number of blocks per group */
158 int64_t e2fs_qbmask; /* = s_blocksize -1 */
159 uint32_t e2fs_fsbtodb; /* Shift to get disk block */
160 uint32_t e2fs_ipg; /* Number of inodes per group */
161 uint32_t e2fs_ipb; /* Number of inodes per block */
162 uint32_t e2fs_itpg; /* Number of inode table per group */
163 uint32_t e2fs_fsize; /* Size of fragments per block */
164 uint32_t e2fs_fpb; /* Number of fragments per block */
165 uint32_t e2fs_fpg; /* Number of fragments per group */
166 uint32_t e2fs_dbpg; /* Number of descriptor blocks per group */
167 uint32_t e2fs_descpb; /* Number of group descriptors per block */
168 uint32_t e2fs_gdbcount; /* Number of group descriptors */
169 uint32_t e2fs_gcount; /* Number of groups */
170 uint32_t e2fs_first_inode;/* First inode on fs */
171 int32_t e2fs_isize; /* Size of inode */
172 uint32_t e2fs_mount_opt;
173 uint32_t e2fs_blocksize_bits;
174 uint32_t e2fs_total_dir; /* Total number of directories */
175 uint8_t *e2fs_contigdirs; /* (u) # of contig. allocated dirs */
176 char e2fs_wasvalid; /* valid at mount time */
177 off_t e2fs_maxfilesize;
178 struct ext2_gd *e2fs_gd; /* Group Descriptors */
179 int32_t e2fs_maxcontig; /* max number of contiguous blks */
180 int32_t e2fs_contigsumsize; /* size of cluster summary array */
181 int32_t *e2fs_maxcluster; /* max cluster in each cyl group */
182 struct csum *e2fs_clustersum; /* cluster summary in each cyl group */
183 };
184
185 /*
186 * The second extended file system version
187 */
188 #define E2FS_DATE "95/08/09"
189 #define E2FS_VERSION "0.5b"
190
191 /*
192 * The second extended file system magic number
193 */
194 #define E2FS_MAGIC 0xEF53
195
196 /*
197 * Revision levels
198 */
199 #define E2FS_REV0 0 /* The good old (original) format */
200 #define E2FS_REV1 1 /* V2 format w/ dynamic inode sizes */
201
202 #define E2FS_CURRENT_REV E2FS_REV0
203 #define E2FS_MAX_SUPP_REV E2FS_REV1
204
205 #define E2FS_REV0_INODE_SIZE 128
206
207 /*
208 * compatible/incompatible features
209 */
210 #define EXT2F_COMPAT_PREALLOC 0x0001
211 #define EXT2F_COMPAT_HASJOURNAL 0x0004
212 #define EXT2F_COMPAT_RESIZE 0x0010
213
214 #define EXT2F_ROCOMPAT_SPARSESUPER 0x0001
215 #define EXT2F_ROCOMPAT_LARGEFILE 0x0002
216 #define EXT2F_ROCOMPAT_BTREE_DIR 0x0004
217 #define EXT4F_ROCOMPAT_EXTRA_ISIZE 0x0040
218
219 #define EXT2F_INCOMPAT_COMP 0x0001
220 #define EXT2F_INCOMPAT_FTYPE 0x0002
221
222 /*
223 * Features supported in this implementation
224 *
225 * We support the following REV1 features:
226 * - EXT2F_ROCOMPAT_SPARSESUPER
227 * - EXT2F_ROCOMPAT_LARGEFILE
228 * - EXT2F_INCOMPAT_FTYPE
229 */
230 #define EXT2F_COMPAT_SUPP 0x0000
231 #define EXT2F_ROCOMPAT_SUPP (EXT2F_ROCOMPAT_SPARSESUPER | \
232 EXT2F_ROCOMPAT_LARGEFILE | \
233 EXT4F_ROCOMPAT_EXTRA_ISIZE)
234 #define EXT2F_INCOMPAT_SUPP EXT2F_INCOMPAT_FTYPE
235
236 /* Assume that user mode programs are passing in an ext2fs superblock, not
237 * a kernel struct super_block. This will allow us to call the feature-test
238 * macros from user land. */
239 #define EXT2_SB(sb) (sb)
240
241 /*
242 * Feature set definitions
243 */
244 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
245 ( EXT2_SB(sb)->e2fs->e2fs_features_compat & htole32(mask) )
246 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
247 ( EXT2_SB(sb)->e2fs->e2fs_features_rocompat & htole32(mask) )
248 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
249 ( EXT2_SB(sb)->e2fs->e2fs_features_incompat & htole32(mask) )
250
251 /*
252 * Definitions of behavior on errors
253 */
254 #define E2FS_BEH_CONTINUE 1 /* continue operation */
255 #define E2FS_BEH_READONLY 2 /* remount fs read only */
256 #define E2FS_BEH_PANIC 3 /* cause panic */
257 #define E2FS_BEH_DEFAULT E2FS_BEH_CONTINUE
258
259 /*
260 * OS identification
261 */
262 #define E2FS_OS_LINUX 0
263 #define E2FS_OS_HURD 1
264 #define E2FS_OS_MASIX 2
265 #define E2FS_OS_FREEBSD 3
266 #define E2FS_OS_LITES 4
267
268 /*
269 * File clean flags
270 */
271 #define E2FS_ISCLEAN 0x0001 /* Unmounted cleanly */
272 #define E2FS_ERRORS 0x0002 /* Errors detected */
273
274 /* ext2 file system block group descriptor */
275
276 struct ext2_gd {
277 uint32_t ext2bgd_b_bitmap; /* blocks bitmap block */
278 uint32_t ext2bgd_i_bitmap; /* inodes bitmap block */
279 uint32_t ext2bgd_i_tables; /* inodes table block */
280 uint16_t ext2bgd_nbfree; /* number of free blocks */
281 uint16_t ext2bgd_nifree; /* number of free inodes */
282 uint16_t ext2bgd_ndirs; /* number of directories */
283 uint16_t reserved;
284 uint32_t reserved2[3];
285 };
286
287 /* cluster summary information */
288
289 struct csum {
290 int8_t cs_init; /* cluster summary has been initialized */
291 int32_t *cs_sum; /* cluster summary array */
292 };
293
294 /* EXT2FS metadatas are stored in little-endian byte order. These macros
295 * helps reading these metadatas
296 */
297
298 #define e2fs_cgload(old, new, size) memcpy((new), (old), (size));
299 #define e2fs_cgsave(old, new, size) memcpy((new), (old), (size));
300
301 /*
302 * Macro-instructions used to manage several block sizes
303 */
304 #define EXT2_MIN_BLOCK_SIZE 1024
305 #define EXT2_MAX_BLOCK_SIZE 4096
306 #define EXT2_MIN_BLOCK_LOG_SIZE 10
307 #if defined(_KERNEL)
308 # define EXT2_BLOCK_SIZE(s) ((s)->e2fs_bsize)
309 #else
310 # define EXT2_BLOCK_SIZE(s) (EXT2_MIN_BLOCK_SIZE << (s)->e2fs_log_bsize)
311 #endif
312 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(uint32_t))
313 #if defined(_KERNEL)
314 # define EXT2_BLOCK_SIZE_BITS(s) ((s)->e2fs_blocksize_bits)
315 #else
316 # define EXT2_BLOCK_SIZE_BITS(s) ((s)->e2fs_log_bsize + 10)
317 #endif
318 #if defined(_KERNEL)
319 #define EXT2_ADDR_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_addr_per_block_bits)
320 #define EXT2_INODE_SIZE(s) (EXT2_SB(s)->e2fs_isize)
321 #define EXT2_FIRST_INO(s) (EXT2_SB(s)->e2fs_first_inode)
322 #else
323 #define EXT2_INODE_SIZE(s) (((s)->s_rev_level == E2FS_REV0) ? \
324 E2FS_REV0 : (s)->s_inode_size)
325 #define EXT2_FIRST_INO(s) (((s)->s_rev_level == E2FS_REV0) ? \
326 E2FS_REV0 : (s)->e2fs_first_ino)
327 #endif
328
329 /*
330 * Macro-instructions used to manage fragments
331 */
332 #define EXT2_MIN_FRAG_SIZE 1024
333 #define EXT2_MAX_FRAG_SIZE 4096
334 #define EXT2_MIN_FRAG_LOG_SIZE 10
335 #if defined(_KERNEL)
336 # define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->e2fs_fsize)
337 # define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->e2fs_fpb)
338 #else
339 # define EXT2_FRAG_SIZE(s) (EXT2_MIN_FRAG_SIZE << (s)->e2fs_log_fsize)
340 # define EXT2_FRAGS_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
341 #endif
342
343 /*
344 * Macro-instructions used to manage group descriptors
345 */
346 #if defined(_KERNEL)
347 # define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->e2fs_bpg)
348 # define EXT2_DESC_PER_BLOCK(s) (EXT2_SB(s)->e2fs_descpb)
349 # define EXT2_DESC_PER_BLOCK_BITS(s) (EXT2_SB(s)->s_desc_per_block_bits)
350 #else
351 # define EXT2_BLOCKS_PER_GROUP(s) ((s)->e2fs_bpg)
352 # define EXT2_DESC_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(struct ext2_gd))
353
354 #endif
355
356 #endif /* !_FS_EXT2FS_EXT2FS_H_ */
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