code.delx.au - refind/blob - filesystems/fsw_ext4_disk.h

   1 /**
   2  * \file fsw_ext4_disk.h
   3  * ext4 file system on-disk structures.
   4  */
   5
   6 /*-
   7  * Copyright (c) 2012 Stefan Agner
   8  * Portions Copyright (c) 2006 Christoph Pfisterer
   9  * Portions Copyright (c) 1991-2012 by various Linux kernel contributors
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  24  */
  25
  26 #ifndef _FSW_EXT4_DISK_H_
  27 #define _FSW_EXT4_DISK_H_
  28
  29 // types
  30
  31 typedef fsw_s8  __s8;
  32 typedef fsw_u8  __u8;
  33 typedef fsw_s16 __s16;
  34 typedef fsw_u16 __u16;
  35 typedef fsw_s32 __s32;
  36 typedef fsw_u32 __u32;
  37 typedef fsw_s64 __s64;
  38 typedef fsw_u64 __u64;
  39
  40 typedef __u16   __le16;
  41 typedef __u32   __le32;
  42 typedef __u64   __le64;
  43
  44 //
  45 // from Linux kernel, fs/ext4/ext4.h
  46 //
  47
  48 /*
  49  * Special inode numbers
  50  */
  51 #define EXT4_BAD_INO             1      /* Bad blocks inode */
  52 #define EXT4_ROOT_INO            2      /* Root inode */
  53 #define EXT4_USR_QUOTA_INO       3      /* User quota inode */
  54 #define EXT4_GRP_QUOTA_INO       4      /* Group quota inode */
  55 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
  56 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
  57 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
  58 #define EXT4_JOURNAL_INO         8      /* Journal inode */
  59
  60 /*
  61  * The second extended file system magic number
  62  */
  63 #define EXT4_SUPER_MAGIC        0xEF53
  64
  65 /*
  66  * Macro-instructions used to manage several block sizes
  67  */
  68 #define EXT4_MIN_BLOCK_SIZE             1024
  69 #define EXT4_MAX_BLOCK_SIZE             4096
  70 #define EXT4_MIN_BLOCK_LOG_SIZE           10
  71 #define EXT4_BLOCK_SIZE(s)              (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
  72 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof (__u32))
  73 #define EXT4_BLOCK_SIZE_BITS(s)         ((s)->s_log_block_size + 10)
  74 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
  75                                  EXT4_GOOD_OLD_INODE_SIZE : \
  76                                  (s)->s_inode_size)
  77
  78 /*
  79  * Structure of a blocks group descriptor
  80  */
  81 struct ext4_group_desc
  82 {
  83         __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
  84         __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
  85         __le32  bg_inode_table_lo;      /* Inodes table block */
  86         __le16  bg_free_blocks_count_lo;/* Free blocks count */
  87         __le16  bg_free_inodes_count_lo;/* Free inodes count */
  88         __le16  bg_used_dirs_count_lo;  /* Directories count */
  89         __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
  90         __le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
  91         __le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
  92         __le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
  93         __le16  bg_itable_unused_lo;    /* Unused inodes count */
  94         __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
  95         __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
  96         __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
  97         __le32  bg_inode_table_hi;      /* Inodes table block MSB */
  98         __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
  99         __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
 100         __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
 101         __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
 102         __le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
 103         __le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
 104         __le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
 105         __u32   bg_reserved;
 106 };
 107
 108
 109 /*
 110  * Macro-instructions used to manage group descriptors
 111  */
 112 #define EXT4_DESC_SIZE(s)              ((s)->s_desc_size)
 113 #define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
 114 #define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
 115 #define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
 116
 117 /*
 118  * Constants relative to the data blocks
 119  */
 120 #define EXT4_NDIR_BLOCKS                12
 121 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
 122 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
 123 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
 124 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
 125
 126 /*
 127  * Inode flags
 128  */
 129 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
 130 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
 131 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
 132 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
 133 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
 134 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
 135 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
 136 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
 137 /* Reserved for compression usage... */
 138 #define EXT4_DIRTY_FL                   0x00000100
 139 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 140 #define EXT4_NOCOMP_FL                  0x00000400 /* Don't compress */
 141 #define EXT4_ECOMPR_FL                  0x00000800 /* Compression error */
 142 /* End compression flags --- maybe not all used */
 143 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
 144 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
 145 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* Reserved for ext3 */
 146 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 147 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 148 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 149 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
 150 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 151 #define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
 152 #define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
 153 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
 154
 155 #define EXT4_FL_USER_VISIBLE            0x004BDFFF /* User visible flags */
 156 #define EXT4_FL_USER_MODIFIABLE         0x004B80FF /* User modifiable flags */
 157
 158
 159 /*
 160  * Structure of an inode on the disk
 161  */
 162 struct ext4_inode {
 163         __le16  i_mode;         /* File mode */
 164         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 165         __le32  i_size_lo;      /* Size in bytes */
 166         __le32  i_atime;        /* Access time */
 167         __le32  i_ctime;        /* Inode Change time */
 168         __le32  i_mtime;        /* Modification time */
 169         __le32  i_dtime;        /* Deletion Time */
 170         __le16  i_gid;          /* Low 16 bits of Group Id */
 171         __le16  i_links_count;  /* Links count */
 172         __le32  i_blocks_lo;    /* Blocks count */
 173         __le32  i_flags;        /* File flags */
 174         union {
 175                 struct {
 176                         __le32  l_i_version;
 177                 } linux1;
 178                 struct {
 179                         __u32  h_i_translator;
 180                 } hurd1;
 181                 struct {
 182                         __u32  m_i_reserved1;
 183                 } masix1;
 184         } osd1;                         /* OS dependent 1 */
 185         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
 186         __le32  i_generation;   /* File version (for NFS) */
 187         __le32  i_file_acl_lo;  /* File ACL */
 188         __le32  i_size_high;
 189         __le32  i_obso_faddr;   /* Obsoleted fragment address */
 190         union {
 191                 struct {
 192                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
 193                         __le16  l_i_file_acl_high;
 194                         __le16  l_i_uid_high;   /* these 2 fields */
 195                         __le16  l_i_gid_high;   /* were reserved2[0] */
 196                         __le16  l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
 197                         __le16  l_i_reserved;
 198                 } linux2;
 199                 struct {
 200                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 201                         __u16   h_i_mode_high;
 202                         __u16   h_i_uid_high;
 203                         __u16   h_i_gid_high;
 204                         __u32   h_i_author;
 205                 } hurd2;
 206                 struct {
 207                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
 208                         __le16  m_i_file_acl_high;
 209                         __u32   m_i_reserved2[2];
 210                 } masix2;
 211         } osd2;                         /* OS dependent 2 */
 212         __le16  i_extra_isize;
 213         __le16  i_checksum_hi;  /* crc32c(uuid+inum+inode) BE */
 214         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
 215         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
 216         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
 217         __le32  i_crtime;       /* File Creation time */
 218         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
 219         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
 220 };
 221
 222 /*
 223  * Structure of the super block
 224  */
 225 struct ext4_super_block {
 226 /*00*/  __le32  s_inodes_count;         /* Inodes count */
 227         __le32  s_blocks_count_lo;      /* Blocks count */
 228         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
 229         __le32  s_free_blocks_count_lo; /* Free blocks count */
 230 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
 231         __le32  s_first_data_block;     /* First Data Block */
 232         __le32  s_log_block_size;       /* Block size */
 233         __le32  s_log_cluster_size;     /* Allocation cluster size */
 234 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
 235         __le32  s_clusters_per_group;   /* # Clusters per group */
 236         __le32  s_inodes_per_group;     /* # Inodes per group */
 237         __le32  s_mtime;                /* Mount time */
 238 /*30*/  __le32  s_wtime;                /* Write time */
 239         __le16  s_mnt_count;            /* Mount count */
 240         __le16  s_max_mnt_count;        /* Maximal mount count */
 241         __le16  s_magic;                /* Magic signature */
 242         __le16  s_state;                /* File system state */
 243         __le16  s_errors;               /* Behaviour when detecting errors */
 244         __le16  s_minor_rev_level;      /* minor revision level */
 245 /*40*/  __le32  s_lastcheck;            /* time of last check */
 246         __le32  s_checkinterval;        /* max. time between checks */
 247         __le32  s_creator_os;           /* OS */
 248         __le32  s_rev_level;            /* Revision level */
 249 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
 250         __le16  s_def_resgid;           /* Default gid for reserved blocks */
 251         /*
 252          * These fields are for EXT4_DYNAMIC_REV superblocks only.
 253          *
 254          * Note: the difference between the compatible feature set and
 255          * the incompatible feature set is that if there is a bit set
 256          * in the incompatible feature set that the kernel doesn't
 257          * know about, it should refuse to mount the filesystem.
 258          *
 259          * e2fsck's requirements are more strict; if it doesn't know
 260          * about a feature in either the compatible or incompatible
 261          * feature set, it must abort and not try to meddle with
 262          * things it doesn't understand...
 263          */
 264         __le32  s_first_ino;            /* First non-reserved inode */
 265         __le16  s_inode_size;           /* size of inode structure */
 266         __le16  s_block_group_nr;       /* block group # of this superblock */
 267         __le32  s_feature_compat;       /* compatible feature set */
 268 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
 269         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 270 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
 271 /*78*/  char    s_volume_name[16];      /* volume name */
 272 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
 273 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
 274         /*
 275          * Performance hints.  Directory preallocation should only
 276          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
 277          */
 278         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 279         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 280         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
 281         /*
 282          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
 283          */
 284 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 285 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
 286         __le32  s_journal_dev;          /* device number of journal file */
 287         __le32  s_last_orphan;          /* start of list of inodes to delete */
 288         __le32  s_hash_seed[4];         /* HTREE hash seed */
 289         __u8    s_def_hash_version;     /* Default hash version to use */
 290         __u8    s_jnl_backup_type;
 291         __le16  s_desc_size;            /* size of group descriptor */
 292 /*100*/ __le32  s_default_mount_opts;
 293         __le32  s_first_meta_bg;        /* First metablock block group */
 294         __le32  s_mkfs_time;            /* When the filesystem was created */
 295         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
 296         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
 297 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
 298         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
 299         __le32  s_free_blocks_count_hi; /* Free blocks count */
 300         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
 301         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
 302         __le32  s_flags;                /* Miscellaneous flags */
 303         __le16  s_raid_stride;          /* RAID stride */
 304         __le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
 305         __le64  s_mmp_block;            /* Block for multi-mount protection */
 306         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
 307         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
 308         __u8    s_checksum_type;        /* metadata checksum algorithm used */
 309         __le16  s_reserved_pad;
 310         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
 311         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
 312         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
 313         __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
 314                                               snapshot's future use */
 315         __le32  s_snapshot_list;        /* inode number of the head of the
 316                                            on-disk snapshot list */
 317 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
 318         __le32  s_error_count;          /* number of fs errors */
 319         __le32  s_first_error_time;     /* first time an error happened */
 320         __le32  s_first_error_ino;      /* inode involved in first error */
 321         __le64  s_first_error_block;    /* block involved of first error */
 322         __u8    s_first_error_func[32]; /* function where the error happened */
 323         __le32  s_first_error_line;     /* line number where error happened */
 324         __le32  s_last_error_time;      /* most recent time of an error */
 325         __le32  s_last_error_ino;       /* inode involved in last error */
 326         __le32  s_last_error_line;      /* line number where error happened */
 327         __le64  s_last_error_block;     /* block involved of last error */
 328         __u8    s_last_error_func[32];  /* function where the error happened */
 329 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
 330         __u8    s_mount_opts[64];
 331         __le32  s_usr_quota_inum;       /* inode for tracking user quota */
 332         __le32  s_grp_quota_inum;       /* inode for tracking group quota */
 333         __le32  s_overhead_clusters;    /* overhead blocks/clusters in fs */
 334         __le32  s_reserved[108];        /* Padding to the end of the block */
 335         __le32  s_checksum;             /* crc32c(superblock) */
 336 };
 337 /*
 338  * Revision levels
 339  */
 340 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
 341 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 342
 343 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
 344 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
 345
 346 #define EXT4_GOOD_OLD_INODE_SIZE 128
 347
 348 /*
 349  * Feature set definitions (only the once we need for read support)
 350  */
 351
 352 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
 353 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
 354 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
 355 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
 356 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
 357 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
 358 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
 359 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
 360 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
 361 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
 362 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
 363 #define EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM  0x2000 /* use crc32c for bg */
 364 #define EXT4_FEATURE_INCOMPAT_LARGEDIR          0x4000 /* >2GB or 3-lvl htree */
 365 #define EXT4_FEATURE_INCOMPAT_INLINEDATA        0x8000 /* data in inode */
 366
 367 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
 368                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
 369                                          EXT4_FEATURE_INCOMPAT_META_BG| \
 370                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
 371                                          EXT4_FEATURE_INCOMPAT_64BIT| \
 372                                          EXT4_FEATURE_INCOMPAT_FLEX_BG| \
 373                                          EXT4_FEATURE_INCOMPAT_MMP)
 374
 375 /*
 376  * Structure of a directory entry
 377  */
 378 #define EXT4_NAME_LEN 255
 379
 380 struct ext4_dir_entry {
 381     __le32  inode;                  /* Inode number */
 382     __le16  rec_len;                /* Directory entry length */
 383     __u8    name_len;               /* Name length */
 384     __u8    file_type;
 385     char    name[EXT4_NAME_LEN];    /* File name */
 386 };
 387 // NOTE: The original Linux kernel header defines ext4_dir_entry with the original
 388 //  layout and ext4_dir_entry_2 with the revised layout. We simply use the revised one.
 389
 390 /*
 391  * Ext2 directory file types.  Only the low 3 bits are used.  The
 392  * other bits are reserved for now.
 393  */
 394 enum {
 395     EXT4_FT_UNKNOWN,
 396     EXT4_FT_REG_FILE,
 397     EXT4_FT_DIR,
 398     EXT4_FT_CHRDEV,
 399     EXT4_FT_BLKDEV,
 400     EXT4_FT_FIFO,
 401     EXT4_FT_SOCK,
 402     EXT4_FT_SYMLINK,
 403     EXT4_FT_MAX
 404 };
 405
 406
 407 #endif