include/linux/ext2_fs.h

   1 /*
   2  *  linux/include/linux/ext2_fs.h
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/include/linux/minix_fs.h
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  */
  15
  16 #ifndef _LINUX_EXT2_FS_H
  17 #define _LINUX_EXT2_FS_H
  18
  19 #include <linux/types.h>
  20 #include <linux/magic.h>
  21
  22 /*
  23  * The second extended filesystem constants/structures
  24  */
  25
  26 /*
  27  * Define EXT2FS_DEBUG to produce debug messages
  28  */
  29 #undef EXT2FS_DEBUG
  30
  31 /*
  32  * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files
  33  */
  34 #define EXT2_PREALLOCATE
  35 #define EXT2_DEFAULT_PREALLOC_BLOCKS    8
  36
  37 /*
  38  * The second extended file system version
  39  */
  40 #define EXT2FS_DATE             "95/08/09"
  41 #define EXT2FS_VERSION          "0.5b"
  42
  43 /*
  44  * Debug code
  45  */
  46 #ifdef EXT2FS_DEBUG
  47 #       define ext2_debug(f, a...)      { \
  48                                         printk ("EXT2-fs DEBUG (%s, %d): %s:", \
  49                                                 __FILE__, __LINE__, __FUNCTION__); \
  50                                         printk (f, ## a); \
  51                                         }
  52 #else
  53 #       define ext2_debug(f, a...)      /**/
  54 #endif
  55
  56 /*
  57  * Special inode numbers
  58  */
  59 #define EXT2_BAD_INO             1      /* Bad blocks inode */
  60 #define EXT2_ROOT_INO            2      /* Root inode */
  61 #define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
  62 #define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
  63
  64 /* First non-reserved inode for old ext2 filesystems */
  65 #define EXT2_GOOD_OLD_FIRST_INO 11
  66
  67 #ifdef __KERNEL__
  68 #include <linux/ext2_fs_sb.h>
  69 static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
  70 {
  71         return sb->s_fs_info;
  72 }
  73 #else
  74 /* Assume that user mode programs are passing in an ext2fs superblock, not
  75  * a kernel struct super_block.  This will allow us to call the feature-test
  76  * macros from user land. */
  77 #define EXT2_SB(sb)     (sb)
  78 #endif
  79
  80 /*
  81  * Maximal count of links to a file
  82  */
  83 #define EXT2_LINK_MAX           32000
  84
  85 /*
  86  * Macro-instructions used to manage several block sizes
  87  */
  88 #define EXT2_MIN_BLOCK_SIZE             1024
  89 #define EXT2_MAX_BLOCK_SIZE             4096
  90 #define EXT2_MIN_BLOCK_LOG_SIZE           10
  91 #ifdef __KERNEL__
  92 # define EXT2_BLOCK_SIZE(s)             ((s)->s_blocksize)
  93 #else
  94 # define EXT2_BLOCK_SIZE(s)             (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
  95 #endif
  96 #define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
  97 #ifdef __KERNEL__
  98 # define EXT2_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
  99 #else
 100 # define EXT2_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
 101 #endif
 102 #ifdef __KERNEL__
 103 #define EXT2_ADDR_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_addr_per_block_bits)
 104 #define EXT2_INODE_SIZE(s)              (EXT2_SB(s)->s_inode_size)
 105 #define EXT2_FIRST_INO(s)               (EXT2_SB(s)->s_first_ino)
 106 #else
 107 #define EXT2_INODE_SIZE(s)      (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
 108                                  EXT2_GOOD_OLD_INODE_SIZE : \
 109                                  (s)->s_inode_size)
 110 #define EXT2_FIRST_INO(s)       (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
 111                                  EXT2_GOOD_OLD_FIRST_INO : \
 112                                  (s)->s_first_ino)
 113 #endif
 114
 115 /*
 116  * Macro-instructions used to manage fragments
 117  */
 118 #define EXT2_MIN_FRAG_SIZE              1024
 119 #define EXT2_MAX_FRAG_SIZE              4096
 120 #define EXT2_MIN_FRAG_LOG_SIZE            10
 121 #ifdef __KERNEL__
 122 # define EXT2_FRAG_SIZE(s)              (EXT2_SB(s)->s_frag_size)
 123 # define EXT2_FRAGS_PER_BLOCK(s)        (EXT2_SB(s)->s_frags_per_block)
 124 #else
 125 # define EXT2_FRAG_SIZE(s)              (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
 126 # define EXT2_FRAGS_PER_BLOCK(s)        (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
 127 #endif
 128
 129 /*
 130  * Structure of a blocks group descriptor
 131  */
 132 struct ext2_group_desc
 133 {
 134         __le32  bg_block_bitmap;                /* Blocks bitmap block */
 135         __le32  bg_inode_bitmap;                /* Inodes bitmap block */
 136         __le32  bg_inode_table;         /* Inodes table block */
 137         __le16  bg_free_blocks_count;   /* Free blocks count */
 138         __le16  bg_free_inodes_count;   /* Free inodes count */
 139         __le16  bg_used_dirs_count;     /* Directories count */
 140         __le16  bg_pad;
 141         __le32  bg_reserved[3];
 142 };
 143
 144 /*
 145  * Macro-instructions used to manage group descriptors
 146  */
 147 #ifdef __KERNEL__
 148 # define EXT2_BLOCKS_PER_GROUP(s)       (EXT2_SB(s)->s_blocks_per_group)
 149 # define EXT2_DESC_PER_BLOCK(s)         (EXT2_SB(s)->s_desc_per_block)
 150 # define EXT2_INODES_PER_GROUP(s)       (EXT2_SB(s)->s_inodes_per_group)
 151 # define EXT2_DESC_PER_BLOCK_BITS(s)    (EXT2_SB(s)->s_desc_per_block_bits)
 152 #else
 153 # define EXT2_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
 154 # define EXT2_DESC_PER_BLOCK(s)         (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
 155 # define EXT2_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
 156 #endif
 157
 158 /*
 159  * Constants relative to the data blocks
 160  */
 161 #define EXT2_NDIR_BLOCKS                12
 162 #define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
 163 #define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
 164 #define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
 165 #define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
 166
 167 /*
 168  * Inode flags (GETFLAGS/SETFLAGS)
 169  */
 170 #define EXT2_SECRM_FL                   FS_SECRM_FL     /* Secure deletion */
 171 #define EXT2_UNRM_FL                    FS_UNRM_FL      /* Undelete */
 172 #define EXT2_COMPR_FL                   FS_COMPR_FL     /* Compress file */
 173 #define EXT2_SYNC_FL                    FS_SYNC_FL      /* Synchronous updates */
 174 #define EXT2_IMMUTABLE_FL               FS_IMMUTABLE_FL /* Immutable file */
 175 #define EXT2_APPEND_FL                  FS_APPEND_FL    /* writes to file may only append */
 176 #define EXT2_NODUMP_FL                  FS_NODUMP_FL    /* do not dump file */
 177 #define EXT2_NOATIME_FL                 FS_NOATIME_FL   /* do not update atime */
 178 /* Reserved for compression usage... */
 179 #define EXT2_DIRTY_FL                   FS_DIRTY_FL
 180 #define EXT2_COMPRBLK_FL                FS_COMPRBLK_FL  /* One or more compressed clusters */
 181 #define EXT2_NOCOMP_FL                  FS_NOCOMP_FL    /* Don't compress */
 182 #define EXT2_ECOMPR_FL                  FS_ECOMPR_FL    /* Compression error */
 183 /* End compression flags --- maybe not all used */
 184 #define EXT2_BTREE_FL                   FS_BTREE_FL     /* btree format dir */
 185 #define EXT2_INDEX_FL                   FS_INDEX_FL     /* hash-indexed directory */
 186 #define EXT2_IMAGIC_FL                  FS_IMAGIC_FL    /* AFS directory */
 187 #define EXT2_JOURNAL_DATA_FL            FS_JOURNAL_DATA_FL /* Reserved for ext3 */
 188 #define EXT2_NOTAIL_FL                  FS_NOTAIL_FL    /* file tail should not be merged */
 189 #define EXT2_DIRSYNC_FL                 FS_DIRSYNC_FL   /* dirsync behaviour (directories only) */
 190 #define EXT2_TOPDIR_FL                  FS_TOPDIR_FL    /* Top of directory hierarchies*/
 191 #define EXT2_RESERVED_FL                FS_RESERVED_FL  /* reserved for ext2 lib */
 192
 193 #define EXT2_FL_USER_VISIBLE            FS_FL_USER_VISIBLE      /* User visible flags */
 194 #define EXT2_FL_USER_MODIFIABLE         FS_FL_USER_MODIFIABLE   /* User modifiable flags */
 195
 196 /*
 197  * ioctl commands
 198  */
 199 #define EXT2_IOC_GETFLAGS               FS_IOC_GETFLAGS
 200 #define EXT2_IOC_SETFLAGS               FS_IOC_SETFLAGS
 201 #define EXT2_IOC_GETVERSION             FS_IOC_GETVERSION
 202 #define EXT2_IOC_SETVERSION             FS_IOC_SETVERSION
 203
 204 /*
 205  * ioctl commands in 32 bit emulation
 206  */
 207 #define EXT2_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 208 #define EXT2_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 209 #define EXT2_IOC32_GETVERSION           FS_IOC32_GETVERSION
 210 #define EXT2_IOC32_SETVERSION           FS_IOC32_SETVERSION
 211
 212 /*
 213  * Structure of an inode on the disk
 214  */
 215 struct ext2_inode {
 216         __le16  i_mode;         /* File mode */
 217         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 218         __le32  i_size;         /* Size in bytes */
 219         __le32  i_atime;        /* Access time */
 220         __le32  i_ctime;        /* Creation time */
 221         __le32  i_mtime;        /* Modification time */
 222         __le32  i_dtime;        /* Deletion Time */
 223         __le16  i_gid;          /* Low 16 bits of Group Id */
 224         __le16  i_links_count;  /* Links count */
 225         __le32  i_blocks;       /* Blocks count */
 226         __le32  i_flags;        /* File flags */
 227         union {
 228                 struct {
 229                         __le32  l_i_reserved1;
 230                 } linux1;
 231                 struct {
 232                         __le32  h_i_translator;
 233                 } hurd1;
 234                 struct {
 235                         __le32  m_i_reserved1;
 236                 } masix1;
 237         } osd1;                         /* OS dependent 1 */
 238         __le32  i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
 239         __le32  i_generation;   /* File version (for NFS) */
 240         __le32  i_file_acl;     /* File ACL */
 241         __le32  i_dir_acl;      /* Directory ACL */
 242         __le32  i_faddr;        /* Fragment address */
 243         union {
 244                 struct {
 245                         __u8    l_i_frag;       /* Fragment number */
 246                         __u8    l_i_fsize;      /* Fragment size */
 247                         __u16   i_pad1;
 248                         __le16  l_i_uid_high;   /* these 2 fields    */
 249                         __le16  l_i_gid_high;   /* were reserved2[0] */
 250                         __u32   l_i_reserved2;
 251                 } linux2;
 252                 struct {
 253                         __u8    h_i_frag;       /* Fragment number */
 254                         __u8    h_i_fsize;      /* Fragment size */
 255                         __le16  h_i_mode_high;
 256                         __le16  h_i_uid_high;
 257                         __le16  h_i_gid_high;
 258                         __le32  h_i_author;
 259                 } hurd2;
 260                 struct {
 261                         __u8    m_i_frag;       /* Fragment number */
 262                         __u8    m_i_fsize;      /* Fragment size */
 263                         __u16   m_pad1;
 264                         __u32   m_i_reserved2[2];
 265                 } masix2;
 266         } osd2;                         /* OS dependent 2 */
 267 };
 268
 269 #define i_size_high     i_dir_acl
 270
 271 #if defined(__KERNEL__) || defined(__linux__)
 272 #define i_reserved1     osd1.linux1.l_i_reserved1
 273 #define i_frag          osd2.linux2.l_i_frag
 274 #define i_fsize         osd2.linux2.l_i_fsize
 275 #define i_uid_low       i_uid
 276 #define i_gid_low       i_gid
 277 #define i_uid_high      osd2.linux2.l_i_uid_high
 278 #define i_gid_high      osd2.linux2.l_i_gid_high
 279 #define i_reserved2     osd2.linux2.l_i_reserved2
 280 #endif
 281
 282 #ifdef  __hurd__
 283 #define i_translator    osd1.hurd1.h_i_translator
 284 #define i_frag          osd2.hurd2.h_i_frag;
 285 #define i_fsize         osd2.hurd2.h_i_fsize;
 286 #define i_uid_high      osd2.hurd2.h_i_uid_high
 287 #define i_gid_high      osd2.hurd2.h_i_gid_high
 288 #define i_author        osd2.hurd2.h_i_author
 289 #endif
 290
 291 #ifdef  __masix__
 292 #define i_reserved1     osd1.masix1.m_i_reserved1
 293 #define i_frag          osd2.masix2.m_i_frag
 294 #define i_fsize         osd2.masix2.m_i_fsize
 295 #define i_reserved2     osd2.masix2.m_i_reserved2
 296 #endif
 297
 298 /*
 299  * File system states
 300  */
 301 #define EXT2_VALID_FS                   0x0001  /* Unmounted cleanly */
 302 #define EXT2_ERROR_FS                   0x0002  /* Errors detected */
 303
 304 /*
 305  * Mount flags
 306  */
 307 #define EXT2_MOUNT_CHECK                0x000001  /* Do mount-time checks */
 308 #define EXT2_MOUNT_OLDALLOC             0x000002  /* Don't use the new Orlov allocator */
 309 #define EXT2_MOUNT_GRPID                0x000004  /* Create files with directory's group */
 310 #define EXT2_MOUNT_DEBUG                0x000008  /* Some debugging messages */
 311 #define EXT2_MOUNT_ERRORS_CONT          0x000010  /* Continue on errors */
 312 #define EXT2_MOUNT_ERRORS_RO            0x000020  /* Remount fs ro on errors */
 313 #define EXT2_MOUNT_ERRORS_PANIC         0x000040  /* Panic on errors */
 314 #define EXT2_MOUNT_MINIX_DF             0x000080  /* Mimics the Minix statfs */
 315 #define EXT2_MOUNT_NOBH                 0x000100  /* No buffer_heads */
 316 #define EXT2_MOUNT_NO_UID32             0x000200  /* Disable 32-bit UIDs */
 317 #define EXT2_MOUNT_XATTR_USER           0x004000  /* Extended user attributes */
 318 #define EXT2_MOUNT_POSIX_ACL            0x008000  /* POSIX Access Control Lists */
 319 #define EXT2_MOUNT_XIP                  0x010000  /* Execute in place */
 320 #define EXT2_MOUNT_USRQUOTA             0x020000 /* user quota */
 321 #define EXT2_MOUNT_GRPQUOTA             0x040000 /* group quota */
 322
 323
 324 #define clear_opt(o, opt)               o &= ~EXT2_MOUNT_##opt
 325 #define set_opt(o, opt)                 o |= EXT2_MOUNT_##opt
 326 #define test_opt(sb, opt)               (EXT2_SB(sb)->s_mount_opt & \
 327                                          EXT2_MOUNT_##opt)
 328 /*
 329  * Maximal mount counts between two filesystem checks
 330  */
 331 #define EXT2_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 332 #define EXT2_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 333
 334 /*
 335  * Behaviour when detecting errors
 336  */
 337 #define EXT2_ERRORS_CONTINUE            1       /* Continue execution */
 338 #define EXT2_ERRORS_RO                  2       /* Remount fs read-only */
 339 #define EXT2_ERRORS_PANIC               3       /* Panic */
 340 #define EXT2_ERRORS_DEFAULT             EXT2_ERRORS_CONTINUE
 341
 342 /*
 343  * Structure of the super block
 344  */
 345 struct ext2_super_block {
 346         __le32  s_inodes_count;         /* Inodes count */
 347         __le32  s_blocks_count;         /* Blocks count */
 348         __le32  s_r_blocks_count;       /* Reserved blocks count */
 349         __le32  s_free_blocks_count;    /* Free blocks count */
 350         __le32  s_free_inodes_count;    /* Free inodes count */
 351         __le32  s_first_data_block;     /* First Data Block */
 352         __le32  s_log_block_size;       /* Block size */
 353         __le32  s_log_frag_size;        /* Fragment size */
 354         __le32  s_blocks_per_group;     /* # Blocks per group */
 355         __le32  s_frags_per_group;      /* # Fragments per group */
 356         __le32  s_inodes_per_group;     /* # Inodes per group */
 357         __le32  s_mtime;                /* Mount time */
 358         __le32  s_wtime;                /* Write time */
 359         __le16  s_mnt_count;            /* Mount count */
 360         __le16  s_max_mnt_count;        /* Maximal mount count */
 361         __le16  s_magic;                /* Magic signature */
 362         __le16  s_state;                /* File system state */
 363         __le16  s_errors;               /* Behaviour when detecting errors */
 364         __le16  s_minor_rev_level;      /* minor revision level */
 365         __le32  s_lastcheck;            /* time of last check */
 366         __le32  s_checkinterval;        /* max. time between checks */
 367         __le32  s_creator_os;           /* OS */
 368         __le32  s_rev_level;            /* Revision level */
 369         __le16  s_def_resuid;           /* Default uid for reserved blocks */
 370         __le16  s_def_resgid;           /* Default gid for reserved blocks */
 371         /*
 372          * These fields are for EXT2_DYNAMIC_REV superblocks only.
 373          *
 374          * Note: the difference between the compatible feature set and
 375          * the incompatible feature set is that if there is a bit set
 376          * in the incompatible feature set that the kernel doesn't
 377          * know about, it should refuse to mount the filesystem.
 378          *
 379          * e2fsck's requirements are more strict; if it doesn't know
 380          * about a feature in either the compatible or incompatible
 381          * feature set, it must abort and not try to meddle with
 382          * things it doesn't understand...
 383          */
 384         __le32  s_first_ino;            /* First non-reserved inode */
 385         __le16   s_inode_size;          /* size of inode structure */
 386         __le16  s_block_group_nr;       /* block group # of this superblock */
 387         __le32  s_feature_compat;       /* compatible feature set */
 388         __le32  s_feature_incompat;     /* incompatible feature set */
 389         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 390         __u8    s_uuid[16];             /* 128-bit uuid for volume */
 391         char    s_volume_name[16];      /* volume name */
 392         char    s_last_mounted[64];     /* directory where last mounted */
 393         __le32  s_algorithm_usage_bitmap; /* For compression */
 394         /*
 395          * Performance hints.  Directory preallocation should only
 396          * happen if the EXT2_COMPAT_PREALLOC flag is on.
 397          */
 398         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 399         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 400         __u16   s_padding1;
 401         /*
 402          * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
 403          */
 404         __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 405         __u32   s_journal_inum;         /* inode number of journal file */
 406         __u32   s_journal_dev;          /* device number of journal file */
 407         __u32   s_last_orphan;          /* start of list of inodes to delete */
 408         __u32   s_hash_seed[4];         /* HTREE hash seed */
 409         __u8    s_def_hash_version;     /* Default hash version to use */
 410         __u8    s_reserved_char_pad;
 411         __u16   s_reserved_word_pad;
 412         __le32  s_default_mount_opts;
 413         __le32  s_first_meta_bg;        /* First metablock block group */
 414         __u32   s_reserved[190];        /* Padding to the end of the block */
 415 };
 416
 417 /*
 418  * Codes for operating systems
 419  */
 420 #define EXT2_OS_LINUX           0
 421 #define EXT2_OS_HURD            1
 422 #define EXT2_OS_MASIX           2
 423 #define EXT2_OS_FREEBSD         3
 424 #define EXT2_OS_LITES           4
 425
 426 /*
 427  * Revision levels
 428  */
 429 #define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
 430 #define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 431
 432 #define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
 433 #define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
 434
 435 #define EXT2_GOOD_OLD_INODE_SIZE 128
 436
 437 /*
 438  * Feature set definitions
 439  */
 440
 441 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
 442         ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
 443 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
 444         ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
 445 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
 446         ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
 447 #define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
 448         EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
 449 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
 450         EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
 451 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
 452         EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
 453 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
 454         EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
 455 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
 456         EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
 457 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
 458         EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
 459
 460 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
 461 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
 462 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
 463 #define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
 464 #define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
 465 #define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
 466 #define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
 467
 468 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
 469 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
 470 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
 471 #define EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
 472
 473 #define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
 474 #define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
 475 #define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
 476 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
 477 #define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
 478 #define EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
 479
 480 #define EXT2_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
 481 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
 482                                          EXT2_FEATURE_INCOMPAT_META_BG)
 483 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 484                                          EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
 485                                          EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
 486 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
 487 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
 488
 489 /*
 490  * Default values for user and/or group using reserved blocks
 491  */
 492 #define EXT2_DEF_RESUID         0
 493 #define EXT2_DEF_RESGID         0
 494
 495 /*
 496  * Default mount options
 497  */
 498 #define EXT2_DEFM_DEBUG         0x0001
 499 #define EXT2_DEFM_BSDGROUPS     0x0002
 500 #define EXT2_DEFM_XATTR_USER    0x0004
 501 #define EXT2_DEFM_ACL           0x0008
 502 #define EXT2_DEFM_UID16         0x0010
 503     /* Not used by ext2, but reserved for use by ext3 */
 504 #define EXT3_DEFM_JMODE         0x0060
 505 #define EXT3_DEFM_JMODE_DATA    0x0020
 506 #define EXT3_DEFM_JMODE_ORDERED 0x0040
 507 #define EXT3_DEFM_JMODE_WBACK   0x0060
 508
 509 /*
 510  * Structure of a directory entry
 511  */
 512 #define EXT2_NAME_LEN 255
 513
 514 struct ext2_dir_entry {
 515         __le32  inode;                  /* Inode number */
 516         __le16  rec_len;                /* Directory entry length */
 517         __le16  name_len;               /* Name length */
 518         char    name[EXT2_NAME_LEN];    /* File name */
 519 };
 520
 521 /*
 522  * The new version of the directory entry.  Since EXT2 structures are
 523  * stored in intel byte order, and the name_len field could never be
 524  * bigger than 255 chars, it's safe to reclaim the extra byte for the
 525  * file_type field.
 526  */
 527 struct ext2_dir_entry_2 {
 528         __le32  inode;                  /* Inode number */
 529         __le16  rec_len;                /* Directory entry length */
 530         __u8    name_len;               /* Name length */
 531         __u8    file_type;
 532         char    name[EXT2_NAME_LEN];    /* File name */
 533 };
 534
 535 /*
 536  * Ext2 directory file types.  Only the low 3 bits are used.  The
 537  * other bits are reserved for now.
 538  */
 539 enum {
 540         EXT2_FT_UNKNOWN,
 541         EXT2_FT_REG_FILE,
 542         EXT2_FT_DIR,
 543         EXT2_FT_CHRDEV,
 544         EXT2_FT_BLKDEV,
 545         EXT2_FT_FIFO,
 546         EXT2_FT_SOCK,
 547         EXT2_FT_SYMLINK,
 548         EXT2_FT_MAX
 549 };
 550
 551 /*
 552  * EXT2_DIR_PAD defines the directory entries boundaries
 553  *
 554  * NOTE: It must be a multiple of 4
 555  */
 556 #define EXT2_DIR_PAD                    4
 557 #define EXT2_DIR_ROUND                  (EXT2_DIR_PAD - 1)
 558 #define EXT2_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT2_DIR_ROUND) & \
 559                                          ~EXT2_DIR_ROUND)
 560
 561 #endif  /* _LINUX_EXT2_FS_H */