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/10.1/sys/fs/ext2fs/ext2fs.h 262723 2014-03-04 03:10:31Z 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 * Super block for an ext2fs file system.
44 */
45 struct ext2fs {
46 uint32_t e2fs_icount; /* Inode count */
47 uint32_t e2fs_bcount; /* blocks count */
48 uint32_t e2fs_rbcount; /* reserved blocks count */
49 uint32_t e2fs_fbcount; /* free blocks count */
50 uint32_t e2fs_ficount; /* free inodes count */
51 uint32_t e2fs_first_dblock; /* first data block */
52 uint32_t e2fs_log_bsize; /* block size = 1024*(2^e2fs_log_bsize) */
53 uint32_t e2fs_log_fsize; /* fragment size */
54 uint32_t e2fs_bpg; /* blocks per group */
55 uint32_t e2fs_fpg; /* frags per group */
56 uint32_t e2fs_ipg; /* inodes per group */
57 uint32_t e2fs_mtime; /* mount time */
58 uint32_t e2fs_wtime; /* write time */
59 uint16_t e2fs_mnt_count; /* mount count */
60 uint16_t e2fs_max_mnt_count; /* max mount count */
61 uint16_t e2fs_magic; /* magic number */
62 uint16_t e2fs_state; /* file system state */
63 uint16_t e2fs_beh; /* behavior on errors */
64 uint16_t e2fs_minrev; /* minor revision level */
65 uint32_t e2fs_lastfsck; /* time of last fsck */
66 uint32_t e2fs_fsckintv; /* max time between fscks */
67 uint32_t e2fs_creator; /* creator OS */
68 uint32_t e2fs_rev; /* revision level */
69 uint16_t e2fs_ruid; /* default uid for reserved blocks */
70 uint16_t e2fs_rgid; /* default gid for reserved blocks */
71 /* EXT2_DYNAMIC_REV superblocks */
72 uint32_t e2fs_first_ino; /* first non-reserved inode */
73 uint16_t e2fs_inode_size; /* size of inode structure */
74 uint16_t e2fs_block_group_nr; /* block grp number of this sblk*/
75 uint32_t e2fs_features_compat; /* compatible feature set */
76 uint32_t e2fs_features_incompat; /* incompatible feature set */
77 uint32_t e2fs_features_rocompat; /* RO-compatible feature set */
78 uint8_t e2fs_uuid[16]; /* 128-bit uuid for volume */
79 char e2fs_vname[16]; /* volume name */
80 char e2fs_fsmnt[64]; /* name mounted on */
81 uint32_t e2fs_algo; /* For compression */
82 uint8_t e2fs_prealloc; /* # of blocks for old prealloc */
83 uint8_t e2fs_dir_prealloc; /* # of blocks for old prealloc dirs */
84 uint16_t e2fs_reserved_ngdb; /* # of reserved gd blocks for resize */
85 char e3fs_journal_uuid[16]; /* uuid of journal superblock */
86 uint32_t e3fs_journal_inum; /* inode number of journal file */
87 uint32_t e3fs_journal_dev; /* device number of journal file */
88 uint32_t e3fs_last_orphan; /* start of list of inodes to delete */
89 uint32_t e3fs_hash_seed[4]; /* HTREE hash seed */
90 char e3fs_def_hash_version; /* Default hash version to use */
91 char e3fs_reserved_char_pad;
92 uint32_t e3fs_default_mount_opts;
93 uint32_t e3fs_first_meta_bg; /* First metablock block group */
94 uint32_t e3fs_mkfs_time; /* when the fs was created */
95 uint32_t e3fs_jnl_blks[17]; /* backup of the journal inode */
96 uint32_t e4fs_bcount_hi; /* block count */
97 uint32_t e4fs_rbcount_hi; /* reserved blocks count */
98 uint32_t e4fs_fbcount_hi; /* free blocks count */
99 uint16_t e4fs_min_extra_isize;/* all inodes have at least some bytes */
100 uint16_t e4fs_want_extra_isize; /* inodes must reserve some bytes */
101 uint32_t e4fs_flags; /* miscellaneous flags */
102 uint16_t e4fs_raid_stride; /* RAID stride */
103 uint16_t e4fs_mmpintv; /* number of seconds to wait in MMP checking */
104 uint64_t e4fs_mmpblk; /* block for multi-mount protection */
105 uint32_t e4fs_raid_stripe_wid;/* blocks on all data disks (N * stride) */
106 uint8_t e4fs_log_gpf; /* FLEX_BG group size */
107 uint8_t e4fs_char_pad2;
108 uint16_t e4fs_pad;
109 uint32_t reserved2[162]; /* Padding to the end of the block */
110 };
111
112 /*
113 * The path name on which the file system is mounted is maintained
114 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
115 * the super block for this name.
116 */
117 #define MAXMNTLEN 512
118
119 /*
120 * In-Memory Superblock
121 */
122
123 struct m_ext2fs {
124 struct ext2fs * e2fs;
125 char e2fs_fsmnt[MAXMNTLEN];/* name mounted on */
126 char e2fs_ronly; /* mounted read-only flag */
127 char e2fs_fmod; /* super block modified flag */
128 uint32_t e2fs_bsize; /* Block size */
129 uint32_t e2fs_bshift; /* calc of logical block no */
130 uint32_t e2fs_bpg; /* Number of blocks per group */
131 int64_t e2fs_qbmask; /* = s_blocksize -1 */
132 uint32_t e2fs_fsbtodb; /* Shift to get disk block */
133 uint32_t e2fs_ipg; /* Number of inodes per group */
134 uint32_t e2fs_ipb; /* Number of inodes per block */
135 uint32_t e2fs_itpg; /* Number of inode table per group */
136 uint32_t e2fs_fsize; /* Size of fragments per block */
137 uint32_t e2fs_fpb; /* Number of fragments per block */
138 uint32_t e2fs_fpg; /* Number of fragments per group */
139 uint32_t e2fs_gdbcount; /* Number of group descriptors */
140 uint32_t e2fs_gcount; /* Number of groups */
141 uint32_t e2fs_isize; /* Size of inode */
142 uint32_t e2fs_total_dir; /* Total number of directories */
143 uint8_t *e2fs_contigdirs; /* (u) # of contig. allocated dirs */
144 char e2fs_wasvalid; /* valid at mount time */
145 off_t e2fs_maxfilesize;
146 struct ext2_gd *e2fs_gd; /* Group Descriptors */
147 int32_t e2fs_contigsumsize; /* size of cluster summary array */
148 int32_t *e2fs_maxcluster; /* max cluster in each cyl group */
149 struct csum *e2fs_clustersum; /* cluster summary in each cyl group */
150 int32_t e2fs_uhash; /* 3 if hash should be signed, 0 if not */
151 };
152
153 /* cluster summary information */
154
155 struct csum {
156 int8_t cs_init; /* cluster summary has been initialized */
157 int32_t *cs_sum; /* cluster summary array */
158 };
159
160 /*
161 * The second extended file system magic number
162 */
163 #define E2FS_MAGIC 0xEF53
164
165 /*
166 * Revision levels
167 */
168 #define E2FS_REV0 0 /* The good old (original) format */
169 #define E2FS_REV1 1 /* V2 format w/ dynamic inode sizes */
170
171 #define E2FS_REV0_INODE_SIZE 128
172
173 /*
174 * compatible/incompatible features
175 */
176 #define EXT2F_COMPAT_PREALLOC 0x0001
177 #define EXT2F_COMPAT_HASJOURNAL 0x0004
178 #define EXT2F_COMPAT_RESIZE 0x0010
179 #define EXT2F_COMPAT_DIRHASHINDEX 0x0020
180
181 #define EXT2F_ROCOMPAT_SPARSESUPER 0x0001
182 #define EXT2F_ROCOMPAT_LARGEFILE 0x0002
183 #define EXT2F_ROCOMPAT_BTREE_DIR 0x0004
184 #define EXT2F_ROCOMPAT_HUGE_FILE 0x0008
185 #define EXT2F_ROCOMPAT_GDT_CSUM 0x0010
186 #define EXT2F_ROCOMPAT_DIR_NLINK 0x0020
187 #define EXT2F_ROCOMPAT_EXTRA_ISIZE 0x0040
188
189 #define EXT2F_INCOMPAT_COMP 0x0001
190 #define EXT2F_INCOMPAT_FTYPE 0x0002
191 #define EXT2F_INCOMPAT_META_BG 0x0010
192 #define EXT2F_INCOMPAT_EXTENTS 0x0040
193 #define EXT2F_INCOMPAT_64BIT 0x0080
194 #define EXT2F_INCOMPAT_MMP 0x0100
195 #define EXT2F_INCOMPAT_FLEX_BG 0x0200
196
197 /*
198 * Features supported in this implementation
199 *
200 * We support the following REV1 features:
201 * - EXT2F_ROCOMPAT_SPARSESUPER
202 * - EXT2F_ROCOMPAT_LARGEFILE
203 * - EXT2F_ROCOMPAT_EXTRA_ISIZE
204 * - EXT2F_INCOMPAT_FTYPE
205 *
206 * We partially support (read-only) the following EXT4 features:
207 * - EXT2F_ROCOMPAT_HUGE_FILE
208 * - EXT2F_INCOMPAT_EXTENTS
209 *
210 * We do not support these EXT4 features but they are irrelevant
211 * for read-only support:
212 * - EXT2F_INCOMPAT_FLEX_BG
213 * - EXT2F_INCOMPAT_META_BG
214 */
215 #define EXT2F_COMPAT_SUPP EXT2F_COMPAT_DIRHASHINDEX
216 #define EXT2F_ROCOMPAT_SUPP (EXT2F_ROCOMPAT_SPARSESUPER | \
217 EXT2F_ROCOMPAT_LARGEFILE | \
218 EXT2F_ROCOMPAT_EXTRA_ISIZE)
219 #define EXT2F_INCOMPAT_SUPP EXT2F_INCOMPAT_FTYPE
220 #define EXT4F_RO_INCOMPAT_SUPP (EXT2F_INCOMPAT_EXTENTS | \
221 EXT2F_INCOMPAT_FLEX_BG | \
222 EXT2F_INCOMPAT_META_BG )
223
224 /* Assume that user mode programs are passing in an ext2fs superblock, not
225 * a kernel struct super_block. This will allow us to call the feature-test
226 * macros from user land. */
227 #define EXT2_SB(sb) (sb)
228
229 /*
230 * Feature set definitions
231 */
232 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
233 ( EXT2_SB(sb)->e2fs->e2fs_features_compat & htole32(mask) )
234 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
235 ( EXT2_SB(sb)->e2fs->e2fs_features_rocompat & htole32(mask) )
236 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
237 ( EXT2_SB(sb)->e2fs->e2fs_features_incompat & htole32(mask) )
238
239 /*
240 * File clean flags
241 */
242 #define E2FS_ISCLEAN 0x0001 /* Unmounted cleanly */
243 #define E2FS_ERRORS 0x0002 /* Errors detected */
244
245 /*
246 * Filesystem miscellaneous flags
247 */
248 #define E2FS_SIGNED_HASH 0x0001
249 #define E2FS_UNSIGNED_HASH 0x0002
250
251 /* ext2 file system block group descriptor */
252
253 struct ext2_gd {
254 uint32_t ext2bgd_b_bitmap; /* blocks bitmap block */
255 uint32_t ext2bgd_i_bitmap; /* inodes bitmap block */
256 uint32_t ext2bgd_i_tables; /* inodes table block */
257 uint16_t ext2bgd_nbfree; /* number of free blocks */
258 uint16_t ext2bgd_nifree; /* number of free inodes */
259 uint16_t ext2bgd_ndirs; /* number of directories */
260 uint16_t ext4bgd_flags; /* block group flags */
261 uint32_t ext4bgd_x_bitmap; /* snapshot exclusion bitmap loc. */
262 uint16_t ext4bgd_b_bmap_csum; /* block bitmap checksum */
263 uint16_t ext4bgd_i_bmap_csum; /* inode bitmap checksum */
264 uint16_t ext4bgd_i_unused; /* unused inode count */
265 uint16_t ext4bgd_csum; /* group descriptor checksum */
266 };
267
268
269 /* EXT2FS metadatas are stored in little-endian byte order. These macros
270 * helps reading these metadatas
271 */
272
273 #define e2fs_cgload(old, new, size) memcpy((new), (old), (size));
274 #define e2fs_cgsave(old, new, size) memcpy((new), (old), (size));
275
276 /*
277 * Macro-instructions used to manage several block sizes
278 */
279 #define EXT2_MAX_BLOCK_SIZE 4096
280 #define EXT2_MIN_BLOCK_LOG_SIZE 10
281 #define EXT2_BLOCK_SIZE(s) ((s)->e2fs_bsize)
282 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(uint32_t))
283 #define EXT2_INODE_SIZE(s) (EXT2_SB(s)->e2fs_isize)
284
285 /*
286 * Macro-instructions used to manage fragments
287 */
288 #define EXT2_MIN_FRAG_SIZE 1024
289 #define EXT2_MAX_FRAG_SIZE 4096
290 #define EXT2_MIN_FRAG_LOG_SIZE 10
291 #define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->e2fs_fsize)
292 #define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->e2fs_fpb)
293
294 /*
295 * Macro-instructions used to manage group descriptors
296 */
297 #define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->e2fs_bpg)
298
299 #endif /* !_FS_EXT2FS_EXT2FS_H_ */
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