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 * Super block for an ext2fs file system.
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;
109 uint32_t reserved2[162]; /* Padding to the end of the block */
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.
117 #define MAXMNTLEN 512
120 * In-Memory Superblock
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 */
152 /* cluster summary information */
155 int8_t cs_init; /* cluster summary has been initialized */
156 int32_t *cs_sum; /* cluster summary array */
160 * The second extended file system magic number
162 #define E2FS_MAGIC 0xEF53
167 #define E2FS_REV0 0 /* The good old (original) format */
168 #define E2FS_REV1 1 /* V2 format w/ dynamic inode sizes */
170 #define E2FS_REV0_INODE_SIZE 128
173 * compatible/incompatible features
175 #define EXT2F_COMPAT_PREALLOC 0x0001
176 #define EXT2F_COMPAT_HASJOURNAL 0x0004
177 #define EXT2F_COMPAT_RESIZE 0x0010
178 #define EXT2F_COMPAT_DIRHASHINDEX 0x0020
180 #define EXT2F_ROCOMPAT_SPARSESUPER 0x0001
181 #define EXT2F_ROCOMPAT_LARGEFILE 0x0002
182 #define EXT2F_ROCOMPAT_BTREE_DIR 0x0004
183 #define EXT2F_ROCOMPAT_HUGE_FILE 0x0008
184 #define EXT2F_ROCOMPAT_GDT_CSUM 0x0010
185 #define EXT2F_ROCOMPAT_DIR_NLINK 0x0020
186 #define EXT2F_ROCOMPAT_EXTRA_ISIZE 0x0040
188 #define EXT2F_INCOMPAT_COMP 0x0001
189 #define EXT2F_INCOMPAT_FTYPE 0x0002
190 #define EXT2F_INCOMPAT_RECOVER 0x0004
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
198 * Features supported in this implementation
200 * We support the following REV1 features:
201 * - EXT2F_ROCOMPAT_SPARSESUPER
202 * - EXT2F_ROCOMPAT_LARGEFILE
203 * - EXT2F_ROCOMPAT_EXTRA_ISIZE
204 * - EXT2F_INCOMPAT_FTYPE
206 * We partially (read-only) support the following EXT4 features:
207 * - EXT2F_ROCOMPAT_HUGE_FILE
208 * - EXT2F_INCOMPAT_EXTENTS
210 * We do not support these EXT4 features but they are irrelevant
211 * for read-only support:
212 * - EXT2F_INCOMPAT_RECOVER
213 * - EXT2F_INCOMPAT_FLEX_BG
214 * - EXT2F_INCOMPAT_META_BG
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_RECOVER | \
222 EXT2F_INCOMPAT_FLEX_BG | \
223 EXT2F_INCOMPAT_META_BG )
225 /* Assume that user mode programs are passing in an ext2fs superblock, not
226 * a kernel struct super_block. This will allow us to call the feature-test
227 * macros from user land. */
228 #define EXT2_SB(sb) (sb)
231 * Feature set definitions
233 #define EXT2_HAS_COMPAT_FEATURE(sb,mask) \
234 ( EXT2_SB(sb)->e2fs->e2fs_features_compat & htole32(mask) )
235 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \
236 ( EXT2_SB(sb)->e2fs->e2fs_features_rocompat & htole32(mask) )
237 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \
238 ( EXT2_SB(sb)->e2fs->e2fs_features_incompat & htole32(mask) )
243 #define E2FS_ISCLEAN 0x0001 /* Unmounted cleanly */
244 #define E2FS_ERRORS 0x0002 /* Errors detected */
246 /* ext2 file system block group descriptor */
249 uint32_t ext2bgd_b_bitmap; /* blocks bitmap block */
250 uint32_t ext2bgd_i_bitmap; /* inodes bitmap block */
251 uint32_t ext2bgd_i_tables; /* inodes table block */
252 uint16_t ext2bgd_nbfree; /* number of free blocks */
253 uint16_t ext2bgd_nifree; /* number of free inodes */
254 uint16_t ext2bgd_ndirs; /* number of directories */
255 uint16_t ext4bgd_flags; /* block group flags */
256 uint32_t ext4bgd_x_bitmap; /* snapshot exclusion bitmap loc. */
257 uint16_t ext4bgd_b_bmap_csum; /* block bitmap checksum */
258 uint16_t ext4bgd_i_bmap_csum; /* inode bitmap checksum */
259 uint16_t ext4bgd_i_unused; /* unused inode count */
260 uint16_t ext4bgd_csum; /* group descriptor checksum */
264 /* EXT2FS metadatas are stored in little-endian byte order. These macros
265 * helps reading these metadatas
268 #define e2fs_cgload(old, new, size) memcpy((new), (old), (size));
269 #define e2fs_cgsave(old, new, size) memcpy((new), (old), (size));
272 * Macro-instructions used to manage several block sizes
274 #define EXT2_MAX_BLOCK_SIZE 4096
275 #define EXT2_MIN_BLOCK_LOG_SIZE 10
276 #define EXT2_BLOCK_SIZE(s) ((s)->e2fs_bsize)
277 #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(uint32_t))
278 #define EXT2_INODE_SIZE(s) (EXT2_SB(s)->e2fs_isize)
281 * Macro-instructions used to manage fragments
283 #define EXT2_MIN_FRAG_SIZE 1024
284 #define EXT2_MAX_FRAG_SIZE 4096
285 #define EXT2_MIN_FRAG_LOG_SIZE 10
286 #define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->e2fs_fsize)
287 #define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->e2fs_fpb)
290 * Macro-instructions used to manage group descriptors
292 #define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->e2fs_bpg)
294 #endif /* !_FS_EXT2FS_EXT2FS_H_ */