code.delx.au - refind/blob - filesystems/fsw_ext2_disk.h

   1 /**
   2  * \file fsw_ext2_disk.h
   3  * ext2 file system on-disk structures.
   4  */
   5
   6 /*-
   7  * Copyright (c) 2006 Christoph Pfisterer
   8  * Portions Copyright (c) 1991-2006 by various Linux kernel contributors
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  23  */
  24
  25 #ifndef _FSW_EXT2_DISK_H_
  26 #define _FSW_EXT2_DISK_H_
  27
  28 // types
  29
  30 typedef fsw_s8  __s8;
  31 typedef fsw_u8  __u8;
  32 typedef fsw_s16 __s16;
  33 typedef fsw_u16 __u16;
  34 typedef fsw_s32 __s32;
  35 typedef fsw_u32 __u32;
  36 typedef fsw_s64 __s64;
  37 typedef fsw_u64 __u64;
  38
  39 typedef __u16   __le16;
  40 typedef __u32   __le32;
  41 typedef __u64   __le64;
  42
  43 //
  44 // from Linux kernel, include/linux/ext2_fs.h
  45 //
  46
  47 /*
  48  * Special inode numbers
  49  */
  50 #define EXT2_BAD_INO             1      /* Bad blocks inode */
  51 #define EXT2_ROOT_INO            2      /* Root inode */
  52 #define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
  53 #define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
  54
  55 /*
  56  * The second extended file system magic number
  57  */
  58 #define EXT2_SUPER_MAGIC        0xEF53
  59
  60 /*
  61  * Macro-instructions used to manage several block sizes
  62  */
  63 #define EXT2_MIN_BLOCK_SIZE             1024
  64 #define EXT2_MAX_BLOCK_SIZE             4096
  65 #define EXT2_MIN_BLOCK_LOG_SIZE           10
  66 #define EXT2_BLOCK_SIZE(s)              (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
  67 #define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
  68 #define EXT2_BLOCK_SIZE_BITS(s)         ((s)->s_log_block_size + 10)
  69 #define EXT2_INODE_SIZE(s)      (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
  70                                  EXT2_GOOD_OLD_INODE_SIZE : \
  71                                  (s)->s_inode_size)
  72 #define EXT2_FIRST_INO(s)       (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
  73                                  EXT2_GOOD_OLD_FIRST_INO : \
  74                                  (s)->s_first_ino)
  75
  76 /*
  77  * Structure of a blocks group descriptor
  78  */
  79 struct ext2_group_desc
  80 {
  81     __le32  bg_block_bitmap;        /* Blocks bitmap block */
  82     __le32  bg_inode_bitmap;        /* Inodes bitmap block */
  83     __le32  bg_inode_table;         /* Inodes table block */
  84     __le16  bg_free_blocks_count;   /* Free blocks count */
  85     __le16  bg_free_inodes_count;   /* Free inodes count */
  86     __le16  bg_used_dirs_count;     /* Directories count */
  87     __le16  bg_pad;
  88     __le32  bg_reserved[3];
  89 };
  90
  91 /*
  92  * Macro-instructions used to manage group descriptors
  93  */
  94 #define EXT2_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
  95 #define EXT2_DESC_PER_BLOCK(s)         (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
  96 #define EXT2_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
  97
  98 /*
  99  * Constants relative to the data blocks
 100  */
 101 #define EXT2_NDIR_BLOCKS                12
 102 #define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
 103 #define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
 104 #define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
 105 #define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
 106
 107 /*
 108  * Inode flags
 109  */
 110 #define EXT2_SECRM_FL                   0x00000001 /* Secure deletion */
 111 #define EXT2_UNRM_FL                    0x00000002 /* Undelete */
 112 #define EXT2_COMPR_FL                   0x00000004 /* Compress file */
 113 #define EXT2_SYNC_FL                    0x00000008 /* Synchronous updates */
 114 #define EXT2_IMMUTABLE_FL               0x00000010 /* Immutable file */
 115 #define EXT2_APPEND_FL                  0x00000020 /* writes to file may only append */
 116 #define EXT2_NODUMP_FL                  0x00000040 /* do not dump file */
 117 #define EXT2_NOATIME_FL                 0x00000080 /* do not update atime */
 118 /* Reserved for compression usage... */
 119 #define EXT2_DIRTY_FL                   0x00000100
 120 #define EXT2_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 121 #define EXT2_NOCOMP_FL                  0x00000400 /* Don't compress */
 122 #define EXT2_ECOMPR_FL                  0x00000800 /* Compression error */
 123 /* End compression flags --- maybe not all used */
 124 #define EXT2_BTREE_FL                   0x00001000 /* btree format dir */
 125 #define EXT2_INDEX_FL                   0x00001000 /* hash-indexed directory */
 126 #define EXT2_IMAGIC_FL                  0x00002000 /* AFS directory */
 127 #define EXT2_JOURNAL_DATA_FL            0x00004000 /* Reserved for ext3 */
 128 #define EXT2_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 129 #define EXT2_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 130 #define EXT2_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 131 #define EXT2_RESERVED_FL                0x80000000 /* reserved for ext2 lib */
 132
 133 #define EXT2_FL_USER_VISIBLE            0x0003DFFF /* User visible flags */
 134 #define EXT2_FL_USER_MODIFIABLE         0x000380FF /* User modifiable flags */
 135
 136 /*
 137  * Structure of an inode on the disk
 138  */
 139 struct ext2_inode {
 140     __le16  i_mode;         /* 0: File mode */
 141     __le16  i_uid;          /* 2: Low 16 bits of Owner Uid */
 142     __le32  i_size;         /* 4: Size in bytes */
 143     __le32  i_atime;        /* 8: Access time */
 144     __le32  i_ctime;        /* 12: Creation time */
 145     __le32  i_mtime;        /* 16: Modification time */
 146     __le32  i_dtime;        /* 20: Deletion Time */
 147     __le16  i_gid;          /* 24: Low 16 bits of Group Id */
 148     __le16  i_links_count;  /* 26: Links count */
 149     __le32  i_blocks;       /* 28: Blocks count */
 150     __le32  i_flags;        /* 32: File flags */
 151     union {
 152         struct {
 153             __le32  l_i_reserved1;
 154         } linux1;
 155         struct {
 156             __le32  h_i_translator;
 157         } hurd1;
 158         struct {
 159             __le32  m_i_reserved1;
 160         } masix1;
 161     } osd1;                         /* 36: OS dependent 1 */
 162     __le32  i_block[EXT2_N_BLOCKS];/* 40: Pointers to blocks */
 163     __le32  i_generation;   /* 100: File version (for NFS) */
 164     __le32  i_file_acl;     /* 104: File ACL */
 165     __le32  i_dir_acl;      /* 108: Directory ACL */
 166     __le32  i_faddr;        /* 112: Fragment address */
 167     union {
 168         struct {
 169             __u8    l_i_frag;       /* 116: Fragment number */
 170             __u8    l_i_fsize;      /* 117: Fragment size */
 171             __u16   i_pad1;
 172             __le16  l_i_uid_high;   /* 120: these 2 fields    */
 173             __le16  l_i_gid_high;   /* 122: were reserved2[0] */
 174             __u32   l_i_reserved2;
 175         } linux2;
 176         struct {
 177             __u8    h_i_frag;       /* Fragment number */
 178             __u8    h_i_fsize;      /* Fragment size */
 179             __le16  h_i_mode_high;
 180             __le16  h_i_uid_high;
 181             __le16  h_i_gid_high;
 182             __le32  h_i_author;
 183         } hurd2;
 184         struct {
 185             __u8    m_i_frag;       /* Fragment number */
 186             __u8    m_i_fsize;      /* Fragment size */
 187             __u16   m_pad1;
 188             __u32   m_i_reserved2[2];
 189         } masix2;
 190     } osd2;                         /* OS dependent 2 */
 191 };
 192
 193 #define i_size_high     i_dir_acl
 194
 195 /*
 196  * Structure of the super block
 197  */
 198 struct ext2_super_block {
 199     __le32  s_inodes_count;         /* Inodes count */
 200     __le32  s_blocks_count;         /* Blocks count */
 201     __le32  s_r_blocks_count;       /* Reserved blocks count */
 202     __le32  s_free_blocks_count;    /* Free blocks count */
 203     __le32  s_free_inodes_count;    /* Free inodes count */
 204     __le32  s_first_data_block;     /* First Data Block */
 205     __le32  s_log_block_size;       /* Block size */
 206     __le32  s_log_frag_size;        /* Fragment size */
 207     __le32  s_blocks_per_group;     /* # Blocks per group */
 208     __le32  s_frags_per_group;      /* # Fragments per group */
 209     __le32  s_inodes_per_group;     /* # Inodes per group */
 210     __le32  s_mtime;                /* Mount time */
 211     __le32  s_wtime;                /* Write time */
 212     __le16  s_mnt_count;            /* Mount count */
 213     __le16  s_max_mnt_count;        /* Maximal mount count */
 214     __le16  s_magic;                /* Magic signature */
 215     __le16  s_state;                /* File system state */
 216     __le16  s_errors;               /* Behaviour when detecting errors */
 217     __le16  s_minor_rev_level;      /* minor revision level */
 218     __le32  s_lastcheck;            /* time of last check */
 219     __le32  s_checkinterval;        /* max. time between checks */
 220     __le32  s_creator_os;           /* OS */
 221     __le32  s_rev_level;            /* Revision level */
 222     __le16  s_def_resuid;           /* Default uid for reserved blocks */
 223     __le16  s_def_resgid;           /* Default gid for reserved blocks */
 224     /*
 225      * These fields are for EXT2_DYNAMIC_REV superblocks only.
 226      *
 227      * Note: the difference between the compatible feature set and
 228      * the incompatible feature set is that if there is a bit set
 229      * in the incompatible feature set that the kernel doesn't
 230      * know about, it should refuse to mount the filesystem.
 231      *
 232      * e2fsck's requirements are more strict; if it doesn't know
 233      * about a feature in either the compatible or incompatible
 234      * feature set, it must abort and not try to meddle with
 235      * things it doesn't understand...
 236      */
 237     __le32  s_first_ino;            /* First non-reserved inode */
 238     __le16  s_inode_size;           /* size of inode structure */
 239     __le16  s_block_group_nr;       /* block group # of this superblock */
 240     __le32  s_feature_compat;       /* compatible feature set */
 241     __le32  s_feature_incompat;     /* incompatible feature set */
 242     __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 243     __u8    s_uuid[16];             /* 128-bit uuid for volume */
 244     char    s_volume_name[16];      /* volume name */
 245     char    s_last_mounted[64];     /* directory where last mounted */
 246     __le32  s_algorithm_usage_bitmap; /* For compression */
 247     /*
 248      * Performance hints.  Directory preallocation should only
 249      * happen if the EXT2_COMPAT_PREALLOC flag is on.
 250      */
 251     __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 252     __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 253     __u16   s_padding1;
 254     /*
 255      * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
 256      */
 257     __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 258     __u32   s_journal_inum;         /* inode number of journal file */
 259     __u32   s_journal_dev;          /* device number of journal file */
 260     __u32   s_last_orphan;          /* start of list of inodes to delete */
 261     __u32   s_hash_seed[4];         /* HTREE hash seed */
 262     __u8    s_def_hash_version;     /* Default hash version to use */
 263     __u8    s_reserved_char_pad;
 264     __u16   s_reserved_word_pad;
 265     __le32  s_default_mount_opts;
 266     __le32  s_first_meta_bg;        /* First metablock block group */
 267     __u32   s_reserved[190];        /* Padding to the end of the block */
 268 };
 269
 270 /*
 271  * Revision levels
 272  */
 273 #define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
 274 #define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 275
 276 #define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
 277 #define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
 278
 279 #define EXT2_GOOD_OLD_INODE_SIZE 128
 280
 281 /*
 282  * Feature set definitions
 283  */
 284
 285 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
 286         ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
 287 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
 288         ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
 289 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
 290         ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
 291 #define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
 292         EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
 293 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
 294         EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
 295 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
 296         EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
 297 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
 298         EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
 299 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
 300         EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
 301 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
 302         EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
 303
 304 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
 305 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
 306 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
 307 #define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
 308 #define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
 309 #define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
 310 #define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
 311
 312 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
 313 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
 314 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
 315 #define EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
 316
 317 #define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
 318 #define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
 319 #define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
 320 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
 321 #define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
 322 #define EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
 323
 324 /*
 325 #define EXT2_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
 326 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
 327                                          EXT2_FEATURE_INCOMPAT_META_BG)
 328 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 329                                          EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
 330                                          EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
 331 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
 332 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
 333 */
 334
 335 /*
 336  * Structure of a directory entry
 337  */
 338 #define EXT2_NAME_LEN 255
 339
 340 struct ext2_dir_entry {
 341     __le32  inode;                  /* Inode number */
 342     __le16  rec_len;                /* Directory entry length */
 343     __u8    name_len;               /* Name length */
 344     __u8    file_type;
 345     char    name[EXT2_NAME_LEN];    /* File name */
 346 };
 347 // NOTE: The original Linux kernel header defines ext2_dir_entry with the original
 348 //  layout and ext2_dir_entry_2 with the revised layout. We simply use the revised one.
 349
 350 /*
 351  * Ext2 directory file types.  Only the low 3 bits are used.  The
 352  * other bits are reserved for now.
 353  */
 354 enum {
 355     EXT2_FT_UNKNOWN,
 356     EXT2_FT_REG_FILE,
 357     EXT2_FT_DIR,
 358     EXT2_FT_CHRDEV,
 359     EXT2_FT_BLKDEV,
 360     EXT2_FT_FIFO,
 361     EXT2_FT_SOCK,
 362     EXT2_FT_SYMLINK,
 363     EXT2_FT_MAX
 364 };
 365
 366
 367 #endif