ext2fs.h revision 281841
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: stable/10/sys/fs/ext2fs/ext2fs.h 281841 2015-04-22 00:38:11Z 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 */ 45struct 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 123struct 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}; 151 152/* cluster summary information */ 153 154struct csum { 155 int8_t cs_init; /* cluster summary has been initialized */ 156 int32_t *cs_sum; /* cluster summary array */ 157}; 158 159/* 160 * The second extended file system magic number 161 */ 162#define E2FS_MAGIC 0xEF53 163 164/* 165 * Revision levels 166 */ 167#define E2FS_REV0 0 /* The good old (original) format */ 168#define E2FS_REV1 1 /* V2 format w/ dynamic inode sizes */ 169 170#define E2FS_REV0_INODE_SIZE 128 171 172/* 173 * compatible/incompatible features 174 */ 175#define EXT2F_COMPAT_PREALLOC 0x0001 176#define EXT2F_COMPAT_HASJOURNAL 0x0004 177#define EXT2F_COMPAT_RESIZE 0x0010 178#define EXT2F_COMPAT_DIRHASHINDEX 0x0020 179 180#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 187 188#define EXT2F_INCOMPAT_COMP 0x0001 189#define EXT2F_INCOMPAT_FTYPE 0x0002 190#define EXT2F_INCOMPAT_META_BG 0x0010 191#define EXT2F_INCOMPAT_EXTENTS 0x0040 192#define EXT2F_INCOMPAT_64BIT 0x0080 193#define EXT2F_INCOMPAT_MMP 0x0100 194#define EXT2F_INCOMPAT_FLEX_BG 0x0200 195 196/* 197 * Features supported in this implementation 198 * 199 * We support the following REV1 features: 200 * - EXT2F_ROCOMPAT_SPARSESUPER 201 * - EXT2F_ROCOMPAT_LARGEFILE 202 * - EXT2F_ROCOMPAT_EXTRA_ISIZE 203 * - EXT2F_INCOMPAT_FTYPE 204 * 205 * We partially support (read-only) the following EXT4 features: 206 * - EXT2F_ROCOMPAT_HUGE_FILE 207 * - EXT2F_INCOMPAT_EXTENTS 208 * 209 * We do not support these EXT4 features but they are irrelevant 210 * for read-only support: 211 * - EXT2F_INCOMPAT_FLEX_BG 212 * - EXT2F_INCOMPAT_META_BG 213 */ 214#define EXT2F_ROCOMPAT_SUPP (EXT2F_ROCOMPAT_SPARSESUPER | \ 215 EXT2F_ROCOMPAT_LARGEFILE | \ 216 EXT2F_ROCOMPAT_EXTRA_ISIZE) 217#define EXT2F_INCOMPAT_SUPP EXT2F_INCOMPAT_FTYPE 218#define EXT4F_RO_INCOMPAT_SUPP (EXT2F_INCOMPAT_EXTENTS | \ 219 EXT2F_INCOMPAT_FLEX_BG | \ 220 EXT2F_INCOMPAT_META_BG ) 221 222/* Assume that user mode programs are passing in an ext2fs superblock, not 223 * a kernel struct super_block. This will allow us to call the feature-test 224 * macros from user land. */ 225#define EXT2_SB(sb) (sb) 226 227/* 228 * Feature set definitions 229 */ 230#define EXT2_HAS_COMPAT_FEATURE(sb,mask) \ 231 ( EXT2_SB(sb)->e2fs->e2fs_features_compat & htole32(mask) ) 232#define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask) \ 233 ( EXT2_SB(sb)->e2fs->e2fs_features_rocompat & htole32(mask) ) 234#define EXT2_HAS_INCOMPAT_FEATURE(sb,mask) \ 235 ( EXT2_SB(sb)->e2fs->e2fs_features_incompat & htole32(mask) ) 236 237/* 238 * File clean flags 239 */ 240#define E2FS_ISCLEAN 0x0001 /* Unmounted cleanly */ 241#define E2FS_ERRORS 0x0002 /* Errors detected */ 242 243/* ext2 file system block group descriptor */ 244 245struct ext2_gd { 246 uint32_t ext2bgd_b_bitmap; /* blocks bitmap block */ 247 uint32_t ext2bgd_i_bitmap; /* inodes bitmap block */ 248 uint32_t ext2bgd_i_tables; /* inodes table block */ 249 uint16_t ext2bgd_nbfree; /* number of free blocks */ 250 uint16_t ext2bgd_nifree; /* number of free inodes */ 251 uint16_t ext2bgd_ndirs; /* number of directories */ 252 uint16_t ext4bgd_flags; /* block group flags */ 253 uint32_t ext4bgd_x_bitmap; /* snapshot exclusion bitmap loc. */ 254 uint16_t ext4bgd_b_bmap_csum; /* block bitmap checksum */ 255 uint16_t ext4bgd_i_bmap_csum; /* inode bitmap checksum */ 256 uint16_t ext4bgd_i_unused; /* unused inode count */ 257 uint16_t ext4bgd_csum; /* group descriptor checksum */ 258}; 259 260 261/* EXT2FS metadatas are stored in little-endian byte order. These macros 262 * helps reading these metadatas 263 */ 264 265#define e2fs_cgload(old, new, size) memcpy((new), (old), (size)); 266#define e2fs_cgsave(old, new, size) memcpy((new), (old), (size)); 267 268/* 269 * Macro-instructions used to manage several block sizes 270 */ 271#define EXT2_MAX_BLOCK_SIZE 4096 272#define EXT2_MIN_BLOCK_LOG_SIZE 10 273#define EXT2_BLOCK_SIZE(s) ((s)->e2fs_bsize) 274#define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof(uint32_t)) 275#define EXT2_INODE_SIZE(s) (EXT2_SB(s)->e2fs_isize) 276 277/* 278 * Macro-instructions used to manage fragments 279 */ 280#define EXT2_MIN_FRAG_SIZE 1024 281#define EXT2_MAX_FRAG_SIZE 4096 282#define EXT2_MIN_FRAG_LOG_SIZE 10 283#define EXT2_FRAG_SIZE(s) (EXT2_SB(s)->e2fs_fsize) 284#define EXT2_FRAGS_PER_BLOCK(s) (EXT2_SB(s)->e2fs_fpb) 285 286/* 287 * Macro-instructions used to manage group descriptors 288 */ 289#define EXT2_BLOCKS_PER_GROUP(s) (EXT2_SB(s)->e2fs_bpg) 290 291#endif /* !_FS_EXT2FS_EXT2FS_H_ */ 292