lib/ext2fs/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 <ext2fs/ext2_types.h>          /* Changed from linux/types.h */
  20
  21 /*
  22  * The second extended filesystem constants/structures
  23  */
  24
  25 /*
  26  * Define EXT2FS_DEBUG to produce debug messages
  27  */
  28 #undef EXT2FS_DEBUG
  29
  30 /*
  31  * Define EXT2_PREALLOCATE to preallocate data blocks for expanding files
  32  */
  33 #define EXT2_PREALLOCATE
  34 #define EXT2_DEFAULT_PREALLOC_BLOCKS    8
  35
  36 /*
  37  * The second extended file system version
  38  */
  39 #define EXT2FS_DATE             "95/08/09"
  40 #define EXT2FS_VERSION          "0.5b"
  41
  42 /*
  43  * Special inode numbers
  44  */
  45 #define EXT2_BAD_INO             1      /* Bad blocks inode */
  46 #define EXT2_ROOT_INO            2      /* Root inode */
  47 #define EXT2_ACL_IDX_INO         3      /* ACL inode */
  48 #define EXT2_ACL_DATA_INO        4      /* ACL inode */
  49 #define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
  50 #define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
  51 #define EXT2_RESIZE_INO          7      /* Reserved group descriptors inode */
  52 #define EXT2_JOURNAL_INO         8      /* Journal inode */
  53
  54 /* First non-reserved inode for old ext2 filesystems */
  55 #define EXT2_GOOD_OLD_FIRST_INO 11
  56
  57 /*
  58  * The second extended file system magic number
  59  */
  60 #define EXT2_SUPER_MAGIC        0xEF53
  61
  62 #ifdef __KERNEL__
  63 #define EXT2_SB(sb)     (&((sb)->u.ext2_sb))
  64 #else
  65 /* Assume that user mode programs are passing in an ext2fs superblock, not
  66  * a kernel struct super_block.  This will allow us to call the feature-test
  67  * macros from user land. */
  68 #define EXT2_SB(sb)     (sb)
  69 #endif
  70
  71 /*
  72  * Maximal count of links to a file
  73  */
  74 #define EXT2_LINK_MAX           32000
  75
  76 /*
  77  * Macro-instructions used to manage several block sizes
  78  */
  79 #define EXT2_MIN_BLOCK_LOG_SIZE         10      /* 1024 */
  80 #define EXT2_MAX_BLOCK_LOG_SIZE         13      /* 8192 */
  81 #define EXT2_MIN_BLOCK_SIZE     (1 << EXT2_MIN_BLOCK_LOG_SIZE)
  82 #define EXT2_MAX_BLOCK_SIZE     (1 << EXT2_MAX_BLOCK_LOG_SIZE)
  83 #ifdef __KERNEL__
  84 #define EXT2_BLOCK_SIZE(s)      ((s)->s_blocksize)
  85 #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits)
  86 #define EXT2_ADDR_PER_BLOCK_BITS(s)     (EXT2_SB(s)->addr_per_block_bits)
  87 #define EXT2_INODE_SIZE(s)      (EXT2_SB(s)->s_inode_size)
  88 #define EXT2_FIRST_INO(s)       (EXT2_SB(s)->s_first_ino)
  89 #else
  90 #define EXT2_BLOCK_SIZE(s)      (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size)
  91 #define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10)
  92 #define EXT2_INODE_SIZE(s)      (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
  93                                  EXT2_GOOD_OLD_INODE_SIZE : (s)->s_inode_size)
  94 #define EXT2_FIRST_INO(s)       (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
  95                                  EXT2_GOOD_OLD_FIRST_INO : (s)->s_first_ino)
  96 #endif
  97 #define EXT2_ADDR_PER_BLOCK(s)  (EXT2_BLOCK_SIZE(s) / sizeof(__u32))
  98
  99 /*
 100  * Macro-instructions used to manage fragments
 101  */
 102 #define EXT2_MIN_FRAG_SIZE              EXT2_MIN_BLOCK_SIZE
 103 #define EXT2_MAX_FRAG_SIZE              EXT2_MAX_BLOCK_SIZE
 104 #define EXT2_MIN_FRAG_LOG_SIZE          EXT2_MIN_BLOCK_LOG_SIZE
 105 #ifdef __KERNEL__
 106 # define EXT2_FRAG_SIZE(s)              (EXT2_SB(s)->s_frag_size)
 107 # define EXT2_FRAGS_PER_BLOCK(s)        (EXT2_SB(s)->s_frags_per_block)
 108 #else
 109 # define EXT2_FRAG_SIZE(s)              (EXT2_MIN_FRAG_SIZE << (s)->s_log_frag_size)
 110 # define EXT2_FRAGS_PER_BLOCK(s)        (EXT2_BLOCK_SIZE(s) / EXT2_FRAG_SIZE(s))
 111 #endif
 112
 113 /*
 114  * ACL structures
 115  */
 116 struct ext2_acl_header  /* Header of Access Control Lists */
 117 {
 118         __u32   aclh_size;
 119         __u32   aclh_file_count;
 120         __u32   aclh_acle_count;
 121         __u32   aclh_first_acle;
 122 };
 123
 124 struct ext2_acl_entry   /* Access Control List Entry */
 125 {
 126         __u32   acle_size;
 127         __u16   acle_perms;     /* Access permissions */
 128         __u16   acle_type;      /* Type of entry */
 129         __u16   acle_tag;       /* User or group identity */
 130         __u16   acle_pad1;
 131         __u32   acle_next;      /* Pointer on next entry for the */
 132                                         /* same inode or on next free entry */
 133 };
 134
 135 /*
 136  * Structure of a blocks group descriptor
 137  */
 138 struct ext2_group_desc
 139 {
 140         __u32   bg_block_bitmap;                /* Blocks bitmap block */
 141         __u32   bg_inode_bitmap;                /* Inodes bitmap block */
 142         __u32   bg_inode_table;         /* Inodes table block */
 143         __u16   bg_free_blocks_count;   /* Free blocks count */
 144         __u16   bg_free_inodes_count;   /* Free inodes count */
 145         __u16   bg_used_dirs_count;     /* Directories count */
 146         __u16   bg_pad;
 147         __u32   bg_reserved[3];
 148 };
 149
 150 /*
 151  * Data structures used by the directory indexing feature
 152  *
 153  * Note: all of the multibyte integer fields are little endian.
 154  */
 155
 156 /*
 157  * Note: dx_root_info is laid out so that if it should somehow get
 158  * overlaid by a dirent the two low bits of the hash version will be
 159  * zero.  Therefore, the hash version mod 4 should never be 0.
 160  * Sincerely, the paranoia department.
 161  */
 162 struct ext2_dx_root_info {
 163         __u32 reserved_zero;
 164         __u8 hash_version; /* 0 now, 1 at release */
 165         __u8 info_length; /* 8 */
 166         __u8 indirect_levels;
 167         __u8 unused_flags;
 168 };
 169
 170 struct ext2_dx_entry {
 171         __u32 hash;
 172         __u32 block;
 173 };
 174
 175 struct ext2_dx_countlimit {
 176         __u16 limit;
 177         __u16 count;
 178 };
 179
 180
 181 /*
 182  * Macro-instructions used to manage group descriptors
 183  */
 184 #define EXT2_BLOCKS_PER_GROUP(s)        (EXT2_SB(s)->s_blocks_per_group)
 185 #define EXT2_INODES_PER_GROUP(s)        (EXT2_SB(s)->s_inodes_per_group)
 186 #define EXT2_INODES_PER_BLOCK(s)        (EXT2_BLOCK_SIZE(s)/EXT2_INODE_SIZE(s))
 187 /* limits imposed by 16-bit value gd_free_{blocks,inode}_count */
 188 #define EXT2_MAX_BLOCKS_PER_GROUP(s)    ((1 << 16) - 8)
 189 #define EXT2_MAX_INODES_PER_GROUP(s)    ((1 << 16) - EXT2_INODES_PER_BLOCK(s))
 190 #ifdef __KERNEL__
 191 #define EXT2_DESC_PER_BLOCK(s)          (EXT2_SB(s)->s_desc_per_block)
 192 #define EXT2_DESC_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_desc_per_block_bits)
 193 #else
 194 #define EXT2_DESC_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))
 195 #endif
 196
 197 /*
 198  * Constants relative to the data blocks
 199  */
 200 #define EXT2_NDIR_BLOCKS                12
 201 #define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
 202 #define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
 203 #define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
 204 #define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
 205
 206 /*
 207  * Inode flags
 208  */
 209 #define EXT2_SECRM_FL                   0x00000001 /* Secure deletion */
 210 #define EXT2_UNRM_FL                    0x00000002 /* Undelete */
 211 #define EXT2_COMPR_FL                   0x00000004 /* Compress file */
 212 #define EXT2_SYNC_FL                    0x00000008 /* Synchronous updates */
 213 #define EXT2_IMMUTABLE_FL               0x00000010 /* Immutable file */
 214 #define EXT2_APPEND_FL                  0x00000020 /* writes to file may only append */
 215 #define EXT2_NODUMP_FL                  0x00000040 /* do not dump file */
 216 #define EXT2_NOATIME_FL                 0x00000080 /* do not update atime */
 217 /* Reserved for compression usage... */
 218 #define EXT2_DIRTY_FL                   0x00000100
 219 #define EXT2_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 220 #define EXT2_NOCOMPR_FL                 0x00000400 /* Access raw compressed data */
 221 #define EXT2_ECOMPR_FL                  0x00000800 /* Compression error */
 222 /* End compression flags --- maybe not all used */
 223 #define EXT2_BTREE_FL                   0x00001000 /* btree format dir */
 224 #define EXT2_INDEX_FL                   0x00001000 /* hash-indexed directory */
 225 #define EXT2_IMAGIC_FL                  0x00002000
 226 #define EXT3_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
 227 #define EXT2_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 228 #define EXT2_RESERVED_FL                0x80000000 /* reserved for ext2 lib */
 229
 230 #define EXT2_FL_USER_VISIBLE            0x0000DFFF /* User visible flags */
 231 #define EXT2_FL_USER_MODIFIABLE         0x000080FF /* User modifiable flags */
 232
 233 /*
 234  * ioctl commands
 235  */
 236 #define EXT2_IOC_GETFLAGS               _IOR('f', 1, long)
 237 #define EXT2_IOC_SETFLAGS               _IOW('f', 2, long)
 238 #define EXT2_IOC_GETVERSION             _IOR('v', 1, long)
 239 #define EXT2_IOC_SETVERSION             _IOW('v', 2, long)
 240
 241 /*
 242  * Structure of an inode on the disk
 243  */
 244 struct ext2_inode {
 245         __u16   i_mode;         /* File mode */
 246         __u16   i_uid;          /* Low 16 bits of Owner Uid */
 247         __u32   i_size;         /* Size in bytes */
 248         __u32   i_atime;        /* Access time */
 249         __u32   i_ctime;        /* Creation time */
 250         __u32   i_mtime;        /* Modification time */
 251         __u32   i_dtime;        /* Deletion Time */
 252         __u16   i_gid;          /* Low 16 bits of Group Id */
 253         __u16   i_links_count;  /* Links count */
 254         __u32   i_blocks;       /* Blocks count */
 255         __u32   i_flags;        /* File flags */
 256         union {
 257                 struct {
 258                         __u32  l_i_reserved1;
 259                 } linux1;
 260                 struct {
 261                         __u32  h_i_translator;
 262                 } hurd1;
 263                 struct {
 264                         __u32  m_i_reserved1;
 265                 } masix1;
 266         } osd1;                         /* OS dependent 1 */
 267         __u32   i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
 268         __u32   i_generation;   /* File version (for NFS) */
 269         __u32   i_file_acl;     /* File ACL */
 270         __u32   i_dir_acl;      /* Directory ACL */
 271         __u32   i_faddr;        /* Fragment address */
 272         union {
 273                 struct {
 274                         __u8    l_i_frag;       /* Fragment number */
 275                         __u8    l_i_fsize;      /* Fragment size */
 276                         __u16   i_pad1;
 277                         __u16   l_i_uid_high;   /* these 2 fields    */
 278                         __u16   l_i_gid_high;   /* were reserved2[0] */
 279                         __u32   l_i_reserved2;
 280                 } linux2;
 281                 struct {
 282                         __u8    h_i_frag;       /* Fragment number */
 283                         __u8    h_i_fsize;      /* Fragment size */
 284                         __u16   h_i_mode_high;
 285                         __u16   h_i_uid_high;
 286                         __u16   h_i_gid_high;
 287                         __u32   h_i_author;
 288                 } hurd2;
 289                 struct {
 290                         __u8    m_i_frag;       /* Fragment number */
 291                         __u8    m_i_fsize;      /* Fragment size */
 292                         __u16   m_pad1;
 293                         __u32   m_i_reserved2[2];
 294                 } masix2;
 295         } osd2;                         /* OS dependent 2 */
 296 };
 297
 298 #define i_size_high     i_dir_acl
 299
 300 #if defined(__KERNEL__) || defined(__linux__)
 301 #define i_reserved1     osd1.linux1.l_i_reserved1
 302 #define i_frag          osd2.linux2.l_i_frag
 303 #define i_fsize         osd2.linux2.l_i_fsize
 304 #define i_uid_low       i_uid
 305 #define i_gid_low       i_gid
 306 #define i_uid_high      osd2.linux2.l_i_uid_high
 307 #define i_gid_high      osd2.linux2.l_i_gid_high
 308 #define i_reserved2     osd2.linux2.l_i_reserved2
 309
 310 #elif defined(__GNU__)
 311
 312 #define i_translator    osd1.hurd1.h_i_translator
 313 #define i_frag          osd2.hurd2.h_i_frag;
 314 #define i_fsize         osd2.hurd2.h_i_fsize;
 315 #define i_uid_high      osd2.hurd2.h_i_uid_high
 316 #define i_gid_high      osd2.hurd2.h_i_gid_high
 317 #define i_author        osd2.hurd2.h_i_author
 318
 319 #elif defined(__masix__)
 320
 321 #define i_reserved1     osd1.masix1.m_i_reserved1
 322 #define i_frag          osd2.masix2.m_i_frag
 323 #define i_fsize         osd2.masix2.m_i_fsize
 324 #define i_reserved2     osd2.masix2.m_i_reserved2
 325
 326 #endif  /* defined(__KERNEL__) || defined(__linux__) */
 327
 328 /*
 329  * File system states
 330  */
 331 #define EXT2_VALID_FS                   0x0001  /* Unmounted cleanly */
 332 #define EXT2_ERROR_FS                   0x0002  /* Errors detected */
 333
 334 /*
 335  * Mount flags
 336  */
 337 #define EXT2_MOUNT_CHECK                0x0001  /* Do mount-time checks */
 338 #define EXT2_MOUNT_GRPID                0x0004  /* Create files with directory's group */
 339 #define EXT2_MOUNT_DEBUG                0x0008  /* Some debugging messages */
 340 #define EXT2_MOUNT_ERRORS_CONT          0x0010  /* Continue on errors */
 341 #define EXT2_MOUNT_ERRORS_RO            0x0020  /* Remount fs ro on errors */
 342 #define EXT2_MOUNT_ERRORS_PANIC         0x0040  /* Panic on errors */
 343 #define EXT2_MOUNT_MINIX_DF             0x0080  /* Mimics the Minix statfs */
 344 #define EXT2_MOUNT_NO_UID32             0x0200  /* Disable 32-bit UIDs */
 345
 346 #define clear_opt(o, opt)               o &= ~EXT2_MOUNT_##opt
 347 #define set_opt(o, opt)                 o |= EXT2_MOUNT_##opt
 348 #define test_opt(sb, opt)               (EXT2_SB(sb)->s_mount_opt & \
 349                                          EXT2_MOUNT_##opt)
 350 /*
 351  * Maximal mount counts between two filesystem checks
 352  */
 353 #define EXT2_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 354 #define EXT2_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 355
 356 /*
 357  * Behaviour when detecting errors
 358  */
 359 #define EXT2_ERRORS_CONTINUE            1       /* Continue execution */
 360 #define EXT2_ERRORS_RO                  2       /* Remount fs read-only */
 361 #define EXT2_ERRORS_PANIC               3       /* Panic */
 362 #define EXT2_ERRORS_DEFAULT             EXT2_ERRORS_CONTINUE
 363
 364 /*
 365  * Structure of the super block
 366  */
 367 struct ext2_super_block {
 368         __u32   s_inodes_count;         /* Inodes count */
 369         __u32   s_blocks_count;         /* Blocks count */
 370         __u32   s_r_blocks_count;       /* Reserved blocks count */
 371         __u32   s_free_blocks_count;    /* Free blocks count */
 372         __u32   s_free_inodes_count;    /* Free inodes count */
 373         __u32   s_first_data_block;     /* First Data Block */
 374         __u32   s_log_block_size;       /* Block size */
 375         __s32   s_log_frag_size;        /* Fragment size */
 376         __u32   s_blocks_per_group;     /* # Blocks per group */
 377         __u32   s_frags_per_group;      /* # Fragments per group */
 378         __u32   s_inodes_per_group;     /* # Inodes per group */
 379         __u32   s_mtime;                /* Mount time */
 380         __u32   s_wtime;                /* Write time */
 381         __u16   s_mnt_count;            /* Mount count */
 382         __s16   s_max_mnt_count;        /* Maximal mount count */
 383         __u16   s_magic;                /* Magic signature */
 384         __u16   s_state;                /* File system state */
 385         __u16   s_errors;               /* Behaviour when detecting errors */
 386         __u16   s_minor_rev_level;      /* minor revision level */
 387         __u32   s_lastcheck;            /* time of last check */
 388         __u32   s_checkinterval;        /* max. time between checks */
 389         __u32   s_creator_os;           /* OS */
 390         __u32   s_rev_level;            /* Revision level */
 391         __u16   s_def_resuid;           /* Default uid for reserved blocks */
 392         __u16   s_def_resgid;           /* Default gid for reserved blocks */
 393         /*
 394          * These fields are for EXT2_DYNAMIC_REV superblocks only.
 395          *
 396          * Note: the difference between the compatible feature set and
 397          * the incompatible feature set is that if there is a bit set
 398          * in the incompatible feature set that the kernel doesn't
 399          * know about, it should refuse to mount the filesystem.
 400          *
 401          * e2fsck's requirements are more strict; if it doesn't know
 402          * about a feature in either the compatible or incompatible
 403          * feature set, it must abort and not try to meddle with
 404          * things it doesn't understand...
 405          */
 406         __u32   s_first_ino;            /* First non-reserved inode */
 407         __u16   s_inode_size;           /* size of inode structure */
 408         __u16   s_block_group_nr;       /* block group # of this superblock */
 409         __u32   s_feature_compat;       /* compatible feature set */
 410         __u32   s_feature_incompat;     /* incompatible feature set */
 411         __u32   s_feature_ro_compat;    /* readonly-compatible feature set */
 412         __u8    s_uuid[16];             /* 128-bit uuid for volume */
 413         char    s_volume_name[16];      /* volume name */
 414         char    s_last_mounted[64];     /* directory where last mounted */
 415         __u32   s_algorithm_usage_bitmap; /* For compression */
 416         /*
 417          * Performance hints.  Directory preallocation should only
 418          * happen if the EXT2_FEATURE_COMPAT_DIR_PREALLOC flag is on.
 419          */
 420         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 421         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 422         __u16   s_padding1;
 423         /*
 424          * Journaling support valid if EXT2_FEATURE_COMPAT_HAS_JOURNAL set.
 425          */
 426         __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 427         __u32   s_journal_inum;         /* inode number of journal file */
 428         __u32   s_journal_dev;          /* device number of journal file */
 429         __u32   s_last_orphan;          /* start of list of inodes to delete */
 430
 431         __u32   s_reserved[197];        /* Padding to the end of the block */
 432 };
 433
 434 /*
 435  * Codes for operating systems
 436  */
 437 #define EXT2_OS_LINUX           0
 438 #define EXT2_OS_HURD            1
 439 #define EXT2_OS_MASIX           2
 440 #define EXT2_OS_FREEBSD         3
 441 #define EXT2_OS_LITES           4
 442
 443 /*
 444  * Revision levels
 445  */
 446 #define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
 447 #define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 448
 449 #define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
 450 #define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
 451
 452 #define EXT2_GOOD_OLD_INODE_SIZE 128
 453
 454 /*
 455  * Feature set definitions
 456  */
 457
 458 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
 459         ( EXT2_SB(sb)->s_feature_compat & (mask) )
 460 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
 461         ( EXT2_SB(sb)->s_feature_ro_compat & (mask) )
 462 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
 463         ( EXT2_SB(sb)->s_feature_incompat & (mask) )
 464
 465 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
 466 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
 467 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
 468 #define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
 469 #define EXT2_FEATURE_COMPAT_RESIZE_INODE        0x0010
 470 #define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
 471
 472 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
 473 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
 474 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
 475
 476 #define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
 477 #define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
 478 #define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
 479 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
 480
 481 #define EXT2_FEATURE_COMPAT_SUPP        0
 482 #define EXT2_FEATURE_INCOMPAT_SUPP      EXT2_FEATURE_INCOMPAT_FILETYPE
 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
 487 /*
 488  * Default values for user and/or group using reserved blocks
 489  */
 490 #define EXT2_DEF_RESUID         0
 491 #define EXT2_DEF_RESGID         0
 492
 493 /*
 494  * Structure of a directory entry
 495  */
 496 #define EXT2_NAME_LEN 255
 497
 498 struct ext2_dir_entry {
 499         __u32   inode;                  /* Inode number */
 500         __u16   rec_len;                /* Directory entry length */
 501         __u16   name_len;               /* Name length */
 502         char    name[EXT2_NAME_LEN];    /* File name */
 503 };
 504
 505 /*
 506  * The new version of the directory entry.  Since EXT2 structures are
 507  * stored in intel byte order, and the name_len field could never be
 508  * bigger than 255 chars, it's safe to reclaim the extra byte for the
 509  * file_type field.
 510  */
 511 struct ext2_dir_entry_2 {
 512         __u32   inode;                  /* Inode number */
 513         __u16   rec_len;                /* Directory entry length */
 514         __u8    name_len;               /* Name length */
 515         __u8    file_type;
 516         char    name[EXT2_NAME_LEN];    /* File name */
 517 };
 518
 519 /*
 520  * Ext2 directory file types.  Only the low 3 bits are used.  The
 521  * other bits are reserved for now.
 522  */
 523 #define EXT2_FT_UNKNOWN         0
 524 #define EXT2_FT_REG_FILE        1
 525 #define EXT2_FT_DIR             2
 526 #define EXT2_FT_CHRDEV          3
 527 #define EXT2_FT_BLKDEV          4
 528 #define EXT2_FT_FIFO            5
 529 #define EXT2_FT_SOCK            6
 530 #define EXT2_FT_SYMLINK         7
 531
 532 #define EXT2_FT_MAX             8
 533
 534 /*
 535  * EXT2_DIR_PAD defines the directory entries boundaries
 536  *
 537  * NOTE: It must be a multiple of 4
 538  */
 539 #define EXT2_DIR_PAD                    4
 540 #define EXT2_DIR_ROUND                  (EXT2_DIR_PAD - 1)
 541 #define EXT2_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT2_DIR_ROUND) & \
 542                                          ~EXT2_DIR_ROUND)
 543
 544 #endif  /* _LINUX_EXT2_FS_H */