2 * modified for EXT2FS support in Lites 1.1
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
10 * Copyright (c) 2009 Aditya Sarawgi
11 * All rights reserved.
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
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.
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
37 #ifndef _FS_EXT2FS_EXT2FS_H_
38 #define _FS_EXT2FS_EXT2FS_H_
40 #include <sys/types.h>
43 * Maximal count of links to a file
45 #define EXT2_LINK_MAX 32000
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.
52 * XXX:FS_MAXCONTIG is set to 16 to conserve space. Here we set
53 * EXT2_MAXCONTIG to 32 for better performance.
55 #define EXT2_MAXCONTIG 32
58 * Constants relative to the data blocks
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))
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.
75 * Super block for an ext2fs file system.
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;
141 uint32_t reserved2[162]; /* Padding to the end of the block */
146 * In-Memory Superblock
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 uint32_t e2fs_bpg; /* Number of blocks per group */
157 int64_t e2fs_qbmask; /* = s_blocksize -1 */
158 uint32_t e2fs_fsbtodb; /* Shift to get disk block */
159 uint32_t e2fs_ipg; /* Number of inodes per group */
160 uint32_t e2fs_ipb; /* Number of inodes per block */
161 uint32_t e2fs_itpg; /* Number of inode table per group */
162 uint32_t e2fs_fsize; /* Size of fragments per block */
163 uint32_t e2fs_fpb; /* Number of fragments per block */
164 uint32_t e2fs_fpg; /* Number of fragments per group */
165 uint32_t e2fs_gdbcount; /* Number of group descriptors */
166 uint32_t e2fs_gcount; /* Number of groups */
167 uint32_t e2fs_isize; /* Size of inode */
168 uint32_t e2fs_total_dir; /* Total number of directories */
169 uint8_t *e2fs_contigdirs; /* (u) # of contig. allocated dirs */
170 char e2fs_wasvalid; /* valid at mount time */
171 off_t e2fs_maxfilesize;
172 struct ext2_gd *e2fs_gd; /* Group Descriptors */
173 int32_t e2fs_contigsumsize; /* size of cluster summary array */
174 int32_t *e2fs_maxcluster; /* max cluster in each cyl group */
175 struct csum *e2fs_clustersum; /* cluster summary in each cyl group */
179 * The second extended file system version
181 #define E2FS_DATE "95/08/09"
182 #define E2FS_VERSION "0.5b"
185 * The second extended file system magic number
187 #define E2FS_MAGIC 0xEF53
192 #define E2FS_REV0 0 /* The good old (original) format */
193 #define E2FS_REV1 1 /* V2 format w/ dynamic inode sizes */
195 #define E2FS_CURRENT_REV E2FS_REV0
196 #define E2FS_MAX_SUPP_REV E2FS_REV1
198 #define E2FS_REV0_INODE_SIZE 128
201 * compatible/incompatible features
203 #define EXT2F_COMPAT_PREALLOC 0x0001
204 #define EXT2F_COMPAT_HASJOURNAL 0x0004
205 #define EXT2F_COMPAT_RESIZE 0x0010
206 #define EXT2F_COMPAT_DIRHASHINDEX 0x0020
208 #define EXT2F_ROCOMPAT_SPARSESUPER 0x0001
209 #define EXT2F_ROCOMPAT_LARGEFILE 0x0002
210 #define EXT2F_ROCOMPAT_BTREE_DIR 0x0004
211 #define EXT2F_ROCOMPAT_HUGE_FILE 0x0008
212 #define EXT2F_ROCOMPAT_GDT_CSUM 0x0010
213 #define EXT2F_ROCOMPAT_DIR_NLINK 0x0020
214 #define EXT2F_ROCOMPAT_EXTRA_ISIZE 0x0040
216 #define EXT2F_INCOMPAT_COMP 0x0001
217 #define EXT2F_INCOMPAT_FTYPE 0x0002
218 #define EXT2F_INCOMPAT_META_BG 0x0010
219 #define EXT2F_INCOMPAT_EXTENTS 0x0040
220 #define EXT2F_INCOMPAT_64BIT 0x0080
221 #define EXT2F_INCOMPAT_MMP 0x0100
222 #define EXT2F_INCOMPAT_FLEX_BG 0x0200
225 * Features supported in this implementation
227 * We support the following REV1 features:
228 * - EXT2F_ROCOMPAT_SPARSESUPER
229 * - EXT2F_ROCOMPAT_LARGEFILE
230 * - EXT2F_INCOMPAT_FTYPE
232 #define EXT2F_COMPAT_SUPP 0x0000
233 #define EXT2F_ROCOMPAT_SUPP (EXT2F_ROCOMPAT_SPARSESUPER | \
234 EXT2F_ROCOMPAT_LARGEFILE | \
235 EXT2F_ROCOMPAT_EXTRA_ISIZE)
236 #define EXT2F_INCOMPAT_SUPP EXT2F_INCOMPAT_FTYPE
238 /* Assume that user mode programs are passing in an ext2fs superblock, not
239 * a kernel struct super_block. This will allow us to call the feature-test
240 * macros from user land. */
241 #define EXT2_SB(sb) (sb)
244 * Feature set definitions
246 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
247 ( EXT2_SB(sb)->e2fs->e2fs_features_compat & htole32(mask) )
248 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
249 ( EXT2_SB(sb)->e2fs->e2fs_features_rocompat & htole32(mask) )
250 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
251 ( EXT2_SB(sb)->e2fs->e2fs_features_incompat & htole32(mask) )
254 * Definitions of behavior on errors
256 #define E2FS_BEH_CONTINUE 1 /* continue operation */
257 #define E2FS_BEH_READONLY 2 /* remount fs read only */
258 #define E2FS_BEH_PANIC 3 /* cause panic */
259 #define E2FS_BEH_DEFAULT E2FS_BEH_CONTINUE
264 #define E2FS_OS_LINUX 0
265 #define E2FS_OS_HURD 1
266 #define E2FS_OS_MASIX 2
267 #define E2FS_OS_FREEBSD 3
268 #define E2FS_OS_LITES 4
273 #define E2FS_ISCLEAN 0x0001 /* Unmounted cleanly */
274 #define E2FS_ERRORS 0x0002 /* Errors detected */
276 /* ext2 file system block group descriptor */
279 uint32_t ext2bgd_b_bitmap; /* blocks bitmap block */
280 uint32_t ext2bgd_i_bitmap; /* inodes bitmap block */
281 uint32_t ext2bgd_i_tables; /* inodes table block */
282 uint16_t ext2bgd_nbfree; /* number of free blocks */
283 uint16_t ext2bgd_nifree; /* number of free inodes */
284 uint16_t ext2bgd_ndirs; /* number of directories */
285 uint16_t ext2bgd_flags; /* block group flags */
286 uint32_t ext2bgd_x_bitmap; /* snapshot exclusion bitmap loc. */
287 uint16_t ext2bgd_b_bmap_csum; /* block bitmap checksum */
288 uint16_t ext2bgd_i_bmap_csum; /* inode bitmap checksum */
289 uint16_t ext2bgd_i_unused; /* unused inode count */
290 uint16_t ext2bgd_csum; /* group descriptor checksum */
293 /* cluster summary information */
296 int8_t cs_init; /* cluster summary has been initialized */
297 int32_t *cs_sum; /* cluster summary array */
300 /* EXT2FS metadatas are stored in little-endian byte order. These macros
301 * helps reading these metadatas
304 #define e2fs_cgload(old, new, size) memcpy((new), (old), (size));
305 #define e2fs_cgsave(old, new, size) memcpy((new), (old), (size));
308 * Macro-instructions used to manage several block sizes
310 #define EXT2_MAX_BLOCK_SIZE 4096
311 #define EXT2_MIN_BLOCK_LOG_SIZE 10
312 #define EXT2_BLOCK_SIZE(s) ((s)->e2fs_bsize)
313 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(uint32_t))
314 #define EXT2_INODE_SIZE(s) (EXT2_SB(s)->e2fs_isize)
317 * Macro-instructions used to manage fragments
319 #define EXT2_MIN_FRAG_SIZE 1024
320 #define EXT2_MAX_FRAG_SIZE 4096
321 #define EXT2_MIN_FRAG_LOG_SIZE 10
322 #define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->e2fs_fsize)
323 #define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->e2fs_fpb)
326 * Macro-instructions used to manage group descriptors
328 #define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->e2fs_bpg)
330 #endif /* !_FS_EXT2FS_EXT2FS_H_ */