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 #include <linux/fs.h>
  22
  23 #include <linux/ext2_fs_sb.h>
  24
  25 /*
  26  * The second extended filesystem constants/structures
  27  */
  28
  29 /*
  30  * Define EXT2FS_DEBUG to produce debug messages
  31  */
  32 #undef EXT2FS_DEBUG
  33
  34 /*
  35  * Define EXT2_RESERVATION to reserve data blocks for expanding files
  36  */
  37 #define EXT2_DEFAULT_RESERVE_BLOCKS     8
  38 /*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
  39 #define EXT2_MAX_RESERVE_BLOCKS         1027
  40 #define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
  41 /*
  42  * The second extended file system version
  43  */
  44 #define EXT2FS_DATE             "95/08/09"
  45 #define EXT2FS_VERSION          "0.5b"
  46
  47 /*
  48  * Debug code
  49  */
  50 #ifdef EXT2FS_DEBUG
  51 #       define ext2_debug(f, a...)      { \
  52                                         printk ("EXT2-fs DEBUG (%s, %d): %s:", \
  53                                                 __FILE__, __LINE__, __func__); \
  54                                         printk (f, ## a); \
  55                                         }
  56 #else
  57 #       define ext2_debug(f, a...)      /**/
  58 #endif
  59
  60 /*
  61  * Special inode numbers
  62  */
  63 #define EXT2_BAD_INO             1      /* Bad blocks inode */
  64 #define EXT2_ROOT_INO            2      /* Root inode */
  65 #define EXT2_BOOT_LOADER_INO     5      /* Boot loader inode */
  66 #define EXT2_UNDEL_DIR_INO       6      /* Undelete directory inode */
  67
  68 /* First non-reserved inode for old ext2 filesystems */
  69 #define EXT2_GOOD_OLD_FIRST_INO 11
  70
  71 static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
  72 {
  73         return sb->s_fs_info;
  74 }
  75
  76 /*
  77  * Maximal count of links to a file
  78  */
  79 #define EXT2_LINK_MAX           32000
  80
  81 /*
  82  * Macro-instructions used to manage several block sizes
  83  */
  84 #define EXT2_MIN_BLOCK_SIZE             1024
  85 #define EXT2_MAX_BLOCK_SIZE             4096
  86 #define EXT2_MIN_BLOCK_LOG_SIZE           10
  87 #define EXT2_BLOCK_SIZE(s)              ((s)->s_blocksize)
  88 #define EXT2_ADDR_PER_BLOCK(s)          (EXT2_BLOCK_SIZE(s) / sizeof (__u32))
  89 #define EXT2_BLOCK_SIZE_BITS(s)         ((s)->s_blocksize_bits)
  90 #define EXT2_ADDR_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_addr_per_block_bits)
  91 #define EXT2_INODE_SIZE(s)              (EXT2_SB(s)->s_inode_size)
  92 #define EXT2_FIRST_INO(s)               (EXT2_SB(s)->s_first_ino)
  93
  94 /*
  95  * Macro-instructions used to manage fragments
  96  */
  97 #define EXT2_MIN_FRAG_SIZE              1024
  98 #define EXT2_MAX_FRAG_SIZE              4096
  99 #define EXT2_MIN_FRAG_LOG_SIZE            10
 100 #define EXT2_FRAG_SIZE(s)               (EXT2_SB(s)->s_frag_size)
 101 #define EXT2_FRAGS_PER_BLOCK(s)         (EXT2_SB(s)->s_frags_per_block)
 102
 103 /*
 104  * Structure of a blocks group descriptor
 105  */
 106 struct ext2_group_desc
 107 {
 108         __le32  bg_block_bitmap;                /* Blocks bitmap block */
 109         __le32  bg_inode_bitmap;                /* Inodes bitmap block */
 110         __le32  bg_inode_table;         /* Inodes table block */
 111         __le16  bg_free_blocks_count;   /* Free blocks count */
 112         __le16  bg_free_inodes_count;   /* Free inodes count */
 113         __le16  bg_used_dirs_count;     /* Directories count */
 114         __le16  bg_pad;
 115         __le32  bg_reserved[3];
 116 };
 117
 118 /*
 119  * Macro-instructions used to manage group descriptors
 120  */
 121 #define EXT2_BLOCKS_PER_GROUP(s)        (EXT2_SB(s)->s_blocks_per_group)
 122 #define EXT2_DESC_PER_BLOCK(s)          (EXT2_SB(s)->s_desc_per_block)
 123 #define EXT2_INODES_PER_GROUP(s)        (EXT2_SB(s)->s_inodes_per_group)
 124 #define EXT2_DESC_PER_BLOCK_BITS(s)     (EXT2_SB(s)->s_desc_per_block_bits)
 125
 126 /*
 127  * Constants relative to the data blocks
 128  */
 129 #define EXT2_NDIR_BLOCKS                12
 130 #define EXT2_IND_BLOCK                  EXT2_NDIR_BLOCKS
 131 #define EXT2_DIND_BLOCK                 (EXT2_IND_BLOCK + 1)
 132 #define EXT2_TIND_BLOCK                 (EXT2_DIND_BLOCK + 1)
 133 #define EXT2_N_BLOCKS                   (EXT2_TIND_BLOCK + 1)
 134
 135 /*
 136  * Inode flags (GETFLAGS/SETFLAGS)
 137  */
 138 #define EXT2_SECRM_FL                   FS_SECRM_FL     /* Secure deletion */
 139 #define EXT2_UNRM_FL                    FS_UNRM_FL      /* Undelete */
 140 #define EXT2_COMPR_FL                   FS_COMPR_FL     /* Compress file */
 141 #define EXT2_SYNC_FL                    FS_SYNC_FL      /* Synchronous updates */
 142 #define EXT2_IMMUTABLE_FL               FS_IMMUTABLE_FL /* Immutable file */
 143 #define EXT2_APPEND_FL                  FS_APPEND_FL    /* writes to file may only append */
 144 #define EXT2_NODUMP_FL                  FS_NODUMP_FL    /* do not dump file */
 145 #define EXT2_NOATIME_FL                 FS_NOATIME_FL   /* do not update atime */
 146 /* Reserved for compression usage... */
 147 #define EXT2_DIRTY_FL                   FS_DIRTY_FL
 148 #define EXT2_COMPRBLK_FL                FS_COMPRBLK_FL  /* One or more compressed clusters */
 149 #define EXT2_NOCOMP_FL                  FS_NOCOMP_FL    /* Don't compress */
 150 #define EXT2_ECOMPR_FL                  FS_ECOMPR_FL    /* Compression error */
 151 /* End compression flags --- maybe not all used */
 152 #define EXT2_BTREE_FL                   FS_BTREE_FL     /* btree format dir */
 153 #define EXT2_INDEX_FL                   FS_INDEX_FL     /* hash-indexed directory */
 154 #define EXT2_IMAGIC_FL                  FS_IMAGIC_FL    /* AFS directory */
 155 #define EXT2_JOURNAL_DATA_FL            FS_JOURNAL_DATA_FL /* Reserved for ext3 */
 156 #define EXT2_NOTAIL_FL                  FS_NOTAIL_FL    /* file tail should not be merged */
 157 #define EXT2_DIRSYNC_FL                 FS_DIRSYNC_FL   /* dirsync behaviour (directories only) */
 158 #define EXT2_TOPDIR_FL                  FS_TOPDIR_FL    /* Top of directory hierarchies*/
 159 #define EXT2_RESERVED_FL                FS_RESERVED_FL  /* reserved for ext2 lib */
 160
 161 #define EXT2_FL_USER_VISIBLE            FS_FL_USER_VISIBLE      /* User visible flags */
 162 #define EXT2_FL_USER_MODIFIABLE         FS_FL_USER_MODIFIABLE   /* User modifiable flags */
 163
 164 /* Flags that should be inherited by new inodes from their parent. */
 165 #define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
 166                            EXT2_SYNC_FL | EXT2_NODUMP_FL |\
 167                            EXT2_NOATIME_FL | EXT2_COMPRBLK_FL |\
 168                            EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
 169                            EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)
 170
 171 /* Flags that are appropriate for regular files (all but dir-specific ones). */
 172 #define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))
 173
 174 /* Flags that are appropriate for non-directories/regular files. */
 175 #define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)
 176
 177 /* Mask out flags that are inappropriate for the given type of inode. */
 178 static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags)
 179 {
 180         if (S_ISDIR(mode))
 181                 return flags;
 182         else if (S_ISREG(mode))
 183                 return flags & EXT2_REG_FLMASK;
 184         else
 185                 return flags & EXT2_OTHER_FLMASK;
 186 }
 187
 188 /*
 189  * ioctl commands
 190  */
 191 #define EXT2_IOC_GETFLAGS               FS_IOC_GETFLAGS
 192 #define EXT2_IOC_SETFLAGS               FS_IOC_SETFLAGS
 193 #define EXT2_IOC_GETVERSION             FS_IOC_GETVERSION
 194 #define EXT2_IOC_SETVERSION             FS_IOC_SETVERSION
 195 #define EXT2_IOC_GETRSVSZ               _IOR('f', 5, long)
 196 #define EXT2_IOC_SETRSVSZ               _IOW('f', 6, long)
 197
 198 /*
 199  * ioctl commands in 32 bit emulation
 200  */
 201 #define EXT2_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 202 #define EXT2_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 203 #define EXT2_IOC32_GETVERSION           FS_IOC32_GETVERSION
 204 #define EXT2_IOC32_SETVERSION           FS_IOC32_SETVERSION
 205
 206 /*
 207  * Structure of an inode on the disk
 208  */
 209 struct ext2_inode {
 210         __le16  i_mode;         /* File mode */
 211         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 212         __le32  i_size;         /* Size in bytes */
 213         __le32  i_atime;        /* Access time */
 214         __le32  i_ctime;        /* Creation time */
 215         __le32  i_mtime;        /* Modification time */
 216         __le32  i_dtime;        /* Deletion Time */
 217         __le16  i_gid;          /* Low 16 bits of Group Id */
 218         __le16  i_links_count;  /* Links count */
 219         __le32  i_blocks;       /* Blocks count */
 220         __le32  i_flags;        /* File flags */
 221         union {
 222                 struct {
 223                         __le32  l_i_reserved1;
 224                 } linux1;
 225                 struct {
 226                         __le32  h_i_translator;
 227                 } hurd1;
 228                 struct {
 229                         __le32  m_i_reserved1;
 230                 } masix1;
 231         } osd1;                         /* OS dependent 1 */
 232         __le32  i_block[EXT2_N_BLOCKS];/* Pointers to blocks */
 233         __le32  i_generation;   /* File version (for NFS) */
 234         __le32  i_file_acl;     /* File ACL */
 235         __le32  i_dir_acl;      /* Directory ACL */
 236         __le32  i_faddr;        /* Fragment address */
 237         union {
 238                 struct {
 239                         __u8    l_i_frag;       /* Fragment number */
 240                         __u8    l_i_fsize;      /* Fragment size */
 241                         __u16   i_pad1;
 242                         __le16  l_i_uid_high;   /* these 2 fields    */
 243                         __le16  l_i_gid_high;   /* were reserved2[0] */
 244                         __u32   l_i_reserved2;
 245                 } linux2;
 246                 struct {
 247                         __u8    h_i_frag;       /* Fragment number */
 248                         __u8    h_i_fsize;      /* Fragment size */
 249                         __le16  h_i_mode_high;
 250                         __le16  h_i_uid_high;
 251                         __le16  h_i_gid_high;
 252                         __le32  h_i_author;
 253                 } hurd2;
 254                 struct {
 255                         __u8    m_i_frag;       /* Fragment number */
 256                         __u8    m_i_fsize;      /* Fragment size */
 257                         __u16   m_pad1;
 258                         __u32   m_i_reserved2[2];
 259                 } masix2;
 260         } osd2;                         /* OS dependent 2 */
 261 };
 262
 263 #define i_size_high     i_dir_acl
 264
 265 #define i_reserved1     osd1.linux1.l_i_reserved1
 266 #define i_frag          osd2.linux2.l_i_frag
 267 #define i_fsize         osd2.linux2.l_i_fsize
 268 #define i_uid_low       i_uid
 269 #define i_gid_low       i_gid
 270 #define i_uid_high      osd2.linux2.l_i_uid_high
 271 #define i_gid_high      osd2.linux2.l_i_gid_high
 272 #define i_reserved2     osd2.linux2.l_i_reserved2
 273
 274 /*
 275  * File system states
 276  */
 277 #define EXT2_VALID_FS                   0x0001  /* Unmounted cleanly */
 278 #define EXT2_ERROR_FS                   0x0002  /* Errors detected */
 279
 280 /*
 281  * Mount flags
 282  */
 283 #define EXT2_MOUNT_CHECK                0x000001  /* Do mount-time checks */
 284 #define EXT2_MOUNT_OLDALLOC             0x000002  /* Don't use the new Orlov allocator */
 285 #define EXT2_MOUNT_GRPID                0x000004  /* Create files with directory's group */
 286 #define EXT2_MOUNT_DEBUG                0x000008  /* Some debugging messages */
 287 #define EXT2_MOUNT_ERRORS_CONT          0x000010  /* Continue on errors */
 288 #define EXT2_MOUNT_ERRORS_RO            0x000020  /* Remount fs ro on errors */
 289 #define EXT2_MOUNT_ERRORS_PANIC         0x000040  /* Panic on errors */
 290 #define EXT2_MOUNT_MINIX_DF             0x000080  /* Mimics the Minix statfs */
 291 #define EXT2_MOUNT_NOBH                 0x000100  /* No buffer_heads */
 292 #define EXT2_MOUNT_NO_UID32             0x000200  /* Disable 32-bit UIDs */
 293 #define EXT2_MOUNT_XATTR_USER           0x004000  /* Extended user attributes */
 294 #define EXT2_MOUNT_POSIX_ACL            0x008000  /* POSIX Access Control Lists */
 295 #define EXT2_MOUNT_XIP                  0x010000  /* Execute in place */
 296 #define EXT2_MOUNT_USRQUOTA             0x020000  /* user quota */
 297 #define EXT2_MOUNT_GRPQUOTA             0x040000  /* group quota */
 298 #define EXT2_MOUNT_RESERVATION          0x080000  /* Preallocation */
 299
 300
 301 #define clear_opt(o, opt)               o &= ~EXT2_MOUNT_##opt
 302 #define set_opt(o, opt)                 o |= EXT2_MOUNT_##opt
 303 #define test_opt(sb, opt)               (EXT2_SB(sb)->s_mount_opt & \
 304                                          EXT2_MOUNT_##opt)
 305 /*
 306  * Maximal mount counts between two filesystem checks
 307  */
 308 #define EXT2_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 309 #define EXT2_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 310
 311 /*
 312  * Behaviour when detecting errors
 313  */
 314 #define EXT2_ERRORS_CONTINUE            1       /* Continue execution */
 315 #define EXT2_ERRORS_RO                  2       /* Remount fs read-only */
 316 #define EXT2_ERRORS_PANIC               3       /* Panic */
 317 #define EXT2_ERRORS_DEFAULT             EXT2_ERRORS_CONTINUE
 318
 319 /*
 320  * Structure of the super block
 321  */
 322 struct ext2_super_block {
 323         __le32  s_inodes_count;         /* Inodes count */
 324         __le32  s_blocks_count;         /* Blocks count */
 325         __le32  s_r_blocks_count;       /* Reserved blocks count */
 326         __le32  s_free_blocks_count;    /* Free blocks count */
 327         __le32  s_free_inodes_count;    /* Free inodes count */
 328         __le32  s_first_data_block;     /* First Data Block */
 329         __le32  s_log_block_size;       /* Block size */
 330         __le32  s_log_frag_size;        /* Fragment size */
 331         __le32  s_blocks_per_group;     /* # Blocks per group */
 332         __le32  s_frags_per_group;      /* # Fragments per group */
 333         __le32  s_inodes_per_group;     /* # Inodes per group */
 334         __le32  s_mtime;                /* Mount time */
 335         __le32  s_wtime;                /* Write time */
 336         __le16  s_mnt_count;            /* Mount count */
 337         __le16  s_max_mnt_count;        /* Maximal mount count */
 338         __le16  s_magic;                /* Magic signature */
 339         __le16  s_state;                /* File system state */
 340         __le16  s_errors;               /* Behaviour when detecting errors */
 341         __le16  s_minor_rev_level;      /* minor revision level */
 342         __le32  s_lastcheck;            /* time of last check */
 343         __le32  s_checkinterval;        /* max. time between checks */
 344         __le32  s_creator_os;           /* OS */
 345         __le32  s_rev_level;            /* Revision level */
 346         __le16  s_def_resuid;           /* Default uid for reserved blocks */
 347         __le16  s_def_resgid;           /* Default gid for reserved blocks */
 348         /*
 349          * These fields are for EXT2_DYNAMIC_REV superblocks only.
 350          *
 351          * Note: the difference between the compatible feature set and
 352          * the incompatible feature set is that if there is a bit set
 353          * in the incompatible feature set that the kernel doesn't
 354          * know about, it should refuse to mount the filesystem.
 355          *
 356          * e2fsck's requirements are more strict; if it doesn't know
 357          * about a feature in either the compatible or incompatible
 358          * feature set, it must abort and not try to meddle with
 359          * things it doesn't understand...
 360          */
 361         __le32  s_first_ino;            /* First non-reserved inode */
 362         __le16   s_inode_size;          /* size of inode structure */
 363         __le16  s_block_group_nr;       /* block group # of this superblock */
 364         __le32  s_feature_compat;       /* compatible feature set */
 365         __le32  s_feature_incompat;     /* incompatible feature set */
 366         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 367         __u8    s_uuid[16];             /* 128-bit uuid for volume */
 368         char    s_volume_name[16];      /* volume name */
 369         char    s_last_mounted[64];     /* directory where last mounted */
 370         __le32  s_algorithm_usage_bitmap; /* For compression */
 371         /*
 372          * Performance hints.  Directory preallocation should only
 373          * happen if the EXT2_COMPAT_PREALLOC flag is on.
 374          */
 375         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 376         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 377         __u16   s_padding1;
 378         /*
 379          * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
 380          */
 381         __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 382         __u32   s_journal_inum;         /* inode number of journal file */
 383         __u32   s_journal_dev;          /* device number of journal file */
 384         __u32   s_last_orphan;          /* start of list of inodes to delete */
 385         __u32   s_hash_seed[4];         /* HTREE hash seed */
 386         __u8    s_def_hash_version;     /* Default hash version to use */
 387         __u8    s_reserved_char_pad;
 388         __u16   s_reserved_word_pad;
 389         __le32  s_default_mount_opts;
 390         __le32  s_first_meta_bg;        /* First metablock block group */
 391         __u32   s_reserved[190];        /* Padding to the end of the block */
 392 };
 393
 394 /*
 395  * Codes for operating systems
 396  */
 397 #define EXT2_OS_LINUX           0
 398 #define EXT2_OS_HURD            1
 399 #define EXT2_OS_MASIX           2
 400 #define EXT2_OS_FREEBSD         3
 401 #define EXT2_OS_LITES           4
 402
 403 /*
 404  * Revision levels
 405  */
 406 #define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
 407 #define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 408
 409 #define EXT2_CURRENT_REV        EXT2_GOOD_OLD_REV
 410 #define EXT2_MAX_SUPP_REV       EXT2_DYNAMIC_REV
 411
 412 #define EXT2_GOOD_OLD_INODE_SIZE 128
 413
 414 /*
 415  * Feature set definitions
 416  */
 417
 418 #define EXT2_HAS_COMPAT_FEATURE(sb,mask)                        \
 419         ( EXT2_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
 420 #define EXT2_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
 421         ( EXT2_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
 422 #define EXT2_HAS_INCOMPAT_FEATURE(sb,mask)                      \
 423         ( EXT2_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
 424 #define EXT2_SET_COMPAT_FEATURE(sb,mask)                        \
 425         EXT2_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
 426 #define EXT2_SET_RO_COMPAT_FEATURE(sb,mask)                     \
 427         EXT2_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
 428 #define EXT2_SET_INCOMPAT_FEATURE(sb,mask)                      \
 429         EXT2_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
 430 #define EXT2_CLEAR_COMPAT_FEATURE(sb,mask)                      \
 431         EXT2_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
 432 #define EXT2_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
 433         EXT2_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
 434 #define EXT2_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
 435         EXT2_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
 436
 437 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC        0x0001
 438 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES       0x0002
 439 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
 440 #define EXT2_FEATURE_COMPAT_EXT_ATTR            0x0008
 441 #define EXT2_FEATURE_COMPAT_RESIZE_INO          0x0010
 442 #define EXT2_FEATURE_COMPAT_DIR_INDEX           0x0020
 443 #define EXT2_FEATURE_COMPAT_ANY                 0xffffffff
 444
 445 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
 446 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
 447 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
 448 #define EXT2_FEATURE_RO_COMPAT_ANY              0xffffffff
 449
 450 #define EXT2_FEATURE_INCOMPAT_COMPRESSION       0x0001
 451 #define EXT2_FEATURE_INCOMPAT_FILETYPE          0x0002
 452 #define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004
 453 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008
 454 #define EXT2_FEATURE_INCOMPAT_META_BG           0x0010
 455 #define EXT2_FEATURE_INCOMPAT_ANY               0xffffffff
 456
 457 #define EXT2_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
 458 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT2_FEATURE_INCOMPAT_FILETYPE| \
 459                                          EXT2_FEATURE_INCOMPAT_META_BG)
 460 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 461                                          EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
 462                                          EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
 463 #define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED      ~EXT2_FEATURE_RO_COMPAT_SUPP
 464 #define EXT2_FEATURE_INCOMPAT_UNSUPPORTED       ~EXT2_FEATURE_INCOMPAT_SUPP
 465
 466 /*
 467  * Default values for user and/or group using reserved blocks
 468  */
 469 #define EXT2_DEF_RESUID         0
 470 #define EXT2_DEF_RESGID         0
 471
 472 /*
 473  * Default mount options
 474  */
 475 #define EXT2_DEFM_DEBUG         0x0001
 476 #define EXT2_DEFM_BSDGROUPS     0x0002
 477 #define EXT2_DEFM_XATTR_USER    0x0004
 478 #define EXT2_DEFM_ACL           0x0008
 479 #define EXT2_DEFM_UID16         0x0010
 480     /* Not used by ext2, but reserved for use by ext3 */
 481 #define EXT3_DEFM_JMODE         0x0060
 482 #define EXT3_DEFM_JMODE_DATA    0x0020
 483 #define EXT3_DEFM_JMODE_ORDERED 0x0040
 484 #define EXT3_DEFM_JMODE_WBACK   0x0060
 485
 486 /*
 487  * Structure of a directory entry
 488  */
 489 #define EXT2_NAME_LEN 255
 490
 491 struct ext2_dir_entry {
 492         __le32  inode;                  /* Inode number */
 493         __le16  rec_len;                /* Directory entry length */
 494         __le16  name_len;               /* Name length */
 495         char    name[EXT2_NAME_LEN];    /* File name */
 496 };
 497
 498 /*
 499  * The new version of the directory entry.  Since EXT2 structures are
 500  * stored in intel byte order, and the name_len field could never be
 501  * bigger than 255 chars, it's safe to reclaim the extra byte for the
 502  * file_type field.
 503  */
 504 struct ext2_dir_entry_2 {
 505         __le32  inode;                  /* Inode number */
 506         __le16  rec_len;                /* Directory entry length */
 507         __u8    name_len;               /* Name length */
 508         __u8    file_type;
 509         char    name[EXT2_NAME_LEN];    /* File name */
 510 };
 511
 512 /*
 513  * Ext2 directory file types.  Only the low 3 bits are used.  The
 514  * other bits are reserved for now.
 515  */
 516 enum {
 517         EXT2_FT_UNKNOWN         = 0,
 518         EXT2_FT_REG_FILE        = 1,
 519         EXT2_FT_DIR             = 2,
 520         EXT2_FT_CHRDEV          = 3,
 521         EXT2_FT_BLKDEV          = 4,
 522         EXT2_FT_FIFO            = 5,
 523         EXT2_FT_SOCK            = 6,
 524         EXT2_FT_SYMLINK         = 7,
 525         EXT2_FT_MAX
 526 };
 527
 528 /*
 529  * EXT2_DIR_PAD defines the directory entries boundaries
 530  *
 531  * NOTE: It must be a multiple of 4
 532  */
 533 #define EXT2_DIR_PAD                    4
 534 #define EXT2_DIR_ROUND                  (EXT2_DIR_PAD - 1)
 535 #define EXT2_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT2_DIR_ROUND) & \
 536                                          ~EXT2_DIR_ROUND)
 537 #define EXT2_MAX_REC_LEN                ((1<<16)-1)
 538
 539 #define EXT2_SB_MAGIC_OFFSET    0x38
 540 #define EXT2_SB_BLOCKS_OFFSET   0x04
 541 #define EXT2_SB_BSIZE_OFFSET    0x18
 542
 543 static inline u64 ext2_image_size(void *ext2_sb)
 544 {
 545         __u8 *p = ext2_sb;
 546         if (*(__le16 *)(p + EXT2_SB_MAGIC_OFFSET) != cpu_to_le16(EXT2_SUPER_MAGIC))
 547                 return 0;
 548         return (u64)le32_to_cpup((__le32 *)(p + EXT2_SB_BLOCKS_OFFSET)) <<
 549                 le32_to_cpup((__le32 *)(p + EXT2_SB_BSIZE_OFFSET));
 550 }
 551
 552 static inline void verify_offsets(void)
 553 {
 554 #define A(x,y) BUILD_BUG_ON(x != offsetof(struct ext2_super_block, y));
 555         A(EXT2_SB_MAGIC_OFFSET, s_magic);
 556         A(EXT2_SB_BLOCKS_OFFSET, s_blocks_count);
 557         A(EXT2_SB_BSIZE_OFFSET, s_log_block_size);
 558 #undef A
 559 }
 560
 561 #endif  /* _LINUX_EXT2_FS_H */