include/linux/ext3_fs.h

   1 /*
   2  *  linux/include/linux/ext3_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_EXT3_FS_H
  17 #define _LINUX_EXT3_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 EXT3FS_DEBUG to produce debug messages
  28  */
  29 #undef EXT3FS_DEBUG
  30
  31 /*
  32  * Define EXT3_RESERVATION to reserve data blocks for expanding files
  33  */
  34 #define EXT3_DEFAULT_RESERVE_BLOCKS     8
  35 /*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
  36 #define EXT3_MAX_RESERVE_BLOCKS         1027
  37 #define EXT3_RESERVE_WINDOW_NOT_ALLOCATED 0
  38
  39 /*
  40  * Debug code
  41  */
  42 #ifdef EXT3FS_DEBUG
  43 #define ext3_debug(f, a...)                                             \
  44         do {                                                            \
  45                 printk (KERN_DEBUG "EXT3-fs DEBUG (%s, %d): %s:",       \
  46                         __FILE__, __LINE__, __func__);          \
  47                 printk (KERN_DEBUG f, ## a);                            \
  48         } while (0)
  49 #else
  50 #define ext3_debug(f, a...)     do {} while (0)
  51 #endif
  52
  53 /*
  54  * Special inodes numbers
  55  */
  56 #define EXT3_BAD_INO             1      /* Bad blocks inode */
  57 #define EXT3_ROOT_INO            2      /* Root inode */
  58 #define EXT3_BOOT_LOADER_INO     5      /* Boot loader inode */
  59 #define EXT3_UNDEL_DIR_INO       6      /* Undelete directory inode */
  60 #define EXT3_RESIZE_INO          7      /* Reserved group descriptors inode */
  61 #define EXT3_JOURNAL_INO         8      /* Journal inode */
  62
  63 /* First non-reserved inode for old ext3 filesystems */
  64 #define EXT3_GOOD_OLD_FIRST_INO 11
  65
  66 /*
  67  * Maximal count of links to a file
  68  */
  69 #define EXT3_LINK_MAX           32000
  70
  71 /*
  72  * Macro-instructions used to manage several block sizes
  73  */
  74 #define EXT3_MIN_BLOCK_SIZE             1024
  75 #define EXT3_MAX_BLOCK_SIZE             65536
  76 #define EXT3_MIN_BLOCK_LOG_SIZE         10
  77 #ifdef __KERNEL__
  78 # define EXT3_BLOCK_SIZE(s)             ((s)->s_blocksize)
  79 #else
  80 # define EXT3_BLOCK_SIZE(s)             (EXT3_MIN_BLOCK_SIZE << (s)->s_log_block_size)
  81 #endif
  82 #define EXT3_ADDR_PER_BLOCK(s)          (EXT3_BLOCK_SIZE(s) / sizeof (__u32))
  83 #ifdef __KERNEL__
  84 # define EXT3_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
  85 #else
  86 # define EXT3_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
  87 #endif
  88 #ifdef __KERNEL__
  89 #define EXT3_ADDR_PER_BLOCK_BITS(s)     (EXT3_SB(s)->s_addr_per_block_bits)
  90 #define EXT3_INODE_SIZE(s)              (EXT3_SB(s)->s_inode_size)
  91 #define EXT3_FIRST_INO(s)               (EXT3_SB(s)->s_first_ino)
  92 #else
  93 #define EXT3_INODE_SIZE(s)      (((s)->s_rev_level == EXT3_GOOD_OLD_REV) ? \
  94                                  EXT3_GOOD_OLD_INODE_SIZE : \
  95                                  (s)->s_inode_size)
  96 #define EXT3_FIRST_INO(s)       (((s)->s_rev_level == EXT3_GOOD_OLD_REV) ? \
  97                                  EXT3_GOOD_OLD_FIRST_INO : \
  98                                  (s)->s_first_ino)
  99 #endif
 100
 101 /*
 102  * Macro-instructions used to manage fragments
 103  */
 104 #define EXT3_MIN_FRAG_SIZE              1024
 105 #define EXT3_MAX_FRAG_SIZE              4096
 106 #define EXT3_MIN_FRAG_LOG_SIZE            10
 107 #ifdef __KERNEL__
 108 # define EXT3_FRAG_SIZE(s)              (EXT3_SB(s)->s_frag_size)
 109 # define EXT3_FRAGS_PER_BLOCK(s)        (EXT3_SB(s)->s_frags_per_block)
 110 #else
 111 # define EXT3_FRAG_SIZE(s)              (EXT3_MIN_FRAG_SIZE << (s)->s_log_frag_size)
 112 # define EXT3_FRAGS_PER_BLOCK(s)        (EXT3_BLOCK_SIZE(s) / EXT3_FRAG_SIZE(s))
 113 #endif
 114
 115 /*
 116  * Structure of a blocks group descriptor
 117  */
 118 struct ext3_group_desc
 119 {
 120         __le32  bg_block_bitmap;                /* Blocks bitmap block */
 121         __le32  bg_inode_bitmap;                /* Inodes bitmap block */
 122         __le32  bg_inode_table;         /* Inodes table block */
 123         __le16  bg_free_blocks_count;   /* Free blocks count */
 124         __le16  bg_free_inodes_count;   /* Free inodes count */
 125         __le16  bg_used_dirs_count;     /* Directories count */
 126         __u16   bg_pad;
 127         __le32  bg_reserved[3];
 128 };
 129
 130 /*
 131  * Macro-instructions used to manage group descriptors
 132  */
 133 #ifdef __KERNEL__
 134 # define EXT3_BLOCKS_PER_GROUP(s)       (EXT3_SB(s)->s_blocks_per_group)
 135 # define EXT3_DESC_PER_BLOCK(s)         (EXT3_SB(s)->s_desc_per_block)
 136 # define EXT3_INODES_PER_GROUP(s)       (EXT3_SB(s)->s_inodes_per_group)
 137 # define EXT3_DESC_PER_BLOCK_BITS(s)    (EXT3_SB(s)->s_desc_per_block_bits)
 138 #else
 139 # define EXT3_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
 140 # define EXT3_DESC_PER_BLOCK(s)         (EXT3_BLOCK_SIZE(s) / sizeof (struct ext3_group_desc))
 141 # define EXT3_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
 142 #endif
 143
 144 /*
 145  * Constants relative to the data blocks
 146  */
 147 #define EXT3_NDIR_BLOCKS                12
 148 #define EXT3_IND_BLOCK                  EXT3_NDIR_BLOCKS
 149 #define EXT3_DIND_BLOCK                 (EXT3_IND_BLOCK + 1)
 150 #define EXT3_TIND_BLOCK                 (EXT3_DIND_BLOCK + 1)
 151 #define EXT3_N_BLOCKS                   (EXT3_TIND_BLOCK + 1)
 152
 153 /*
 154  * Inode flags
 155  */
 156 #define EXT3_SECRM_FL                   0x00000001 /* Secure deletion */
 157 #define EXT3_UNRM_FL                    0x00000002 /* Undelete */
 158 #define EXT3_COMPR_FL                   0x00000004 /* Compress file */
 159 #define EXT3_SYNC_FL                    0x00000008 /* Synchronous updates */
 160 #define EXT3_IMMUTABLE_FL               0x00000010 /* Immutable file */
 161 #define EXT3_APPEND_FL                  0x00000020 /* writes to file may only append */
 162 #define EXT3_NODUMP_FL                  0x00000040 /* do not dump file */
 163 #define EXT3_NOATIME_FL                 0x00000080 /* do not update atime */
 164 /* Reserved for compression usage... */
 165 #define EXT3_DIRTY_FL                   0x00000100
 166 #define EXT3_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
 167 #define EXT3_NOCOMPR_FL                 0x00000400 /* Don't compress */
 168 #define EXT3_ECOMPR_FL                  0x00000800 /* Compression error */
 169 /* End compression flags --- maybe not all used */
 170 #define EXT3_INDEX_FL                   0x00001000 /* hash-indexed directory */
 171 #define EXT3_IMAGIC_FL                  0x00002000 /* AFS directory */
 172 #define EXT3_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
 173 #define EXT3_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
 174 #define EXT3_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 175 #define EXT3_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 176 #define EXT3_RESERVED_FL                0x80000000 /* reserved for ext3 lib */
 177
 178 #define EXT3_FL_USER_VISIBLE            0x0003DFFF /* User visible flags */
 179 #define EXT3_FL_USER_MODIFIABLE         0x000380FF /* User modifiable flags */
 180
 181 /*
 182  * Inode dynamic state flags
 183  */
 184 #define EXT3_STATE_JDATA                0x00000001 /* journaled data exists */
 185 #define EXT3_STATE_NEW                  0x00000002 /* inode is newly created */
 186 #define EXT3_STATE_XATTR                0x00000004 /* has in-inode xattrs */
 187
 188 /* Used to pass group descriptor data when online resize is done */
 189 struct ext3_new_group_input {
 190         __u32 group;            /* Group number for this data */
 191         __u32 block_bitmap;     /* Absolute block number of block bitmap */
 192         __u32 inode_bitmap;     /* Absolute block number of inode bitmap */
 193         __u32 inode_table;      /* Absolute block number of inode table start */
 194         __u32 blocks_count;     /* Total number of blocks in this group */
 195         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
 196         __u16 unused;
 197 };
 198
 199 /* The struct ext3_new_group_input in kernel space, with free_blocks_count */
 200 struct ext3_new_group_data {
 201         __u32 group;
 202         __u32 block_bitmap;
 203         __u32 inode_bitmap;
 204         __u32 inode_table;
 205         __u32 blocks_count;
 206         __u16 reserved_blocks;
 207         __u16 unused;
 208         __u32 free_blocks_count;
 209 };
 210
 211
 212 /*
 213  * ioctl commands
 214  */
 215 #define EXT3_IOC_GETFLAGS               FS_IOC_GETFLAGS
 216 #define EXT3_IOC_SETFLAGS               FS_IOC_SETFLAGS
 217 #define EXT3_IOC_GETVERSION             _IOR('f', 3, long)
 218 #define EXT3_IOC_SETVERSION             _IOW('f', 4, long)
 219 #define EXT3_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
 220 #define EXT3_IOC_GROUP_ADD              _IOW('f', 8,struct ext3_new_group_input)
 221 #define EXT3_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
 222 #define EXT3_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
 223 #ifdef CONFIG_JBD_DEBUG
 224 #define EXT3_IOC_WAIT_FOR_READONLY      _IOR('f', 99, long)
 225 #endif
 226 #define EXT3_IOC_GETRSVSZ               _IOR('f', 5, long)
 227 #define EXT3_IOC_SETRSVSZ               _IOW('f', 6, long)
 228
 229 /*
 230  * ioctl commands in 32 bit emulation
 231  */
 232 #define EXT3_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
 233 #define EXT3_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
 234 #define EXT3_IOC32_GETVERSION           _IOR('f', 3, int)
 235 #define EXT3_IOC32_SETVERSION           _IOW('f', 4, int)
 236 #define EXT3_IOC32_GETRSVSZ             _IOR('f', 5, int)
 237 #define EXT3_IOC32_SETRSVSZ             _IOW('f', 6, int)
 238 #define EXT3_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
 239 #ifdef CONFIG_JBD_DEBUG
 240 #define EXT3_IOC32_WAIT_FOR_READONLY    _IOR('f', 99, int)
 241 #endif
 242 #define EXT3_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
 243 #define EXT3_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
 244
 245
 246 /*
 247  *  Mount options
 248  */
 249 struct ext3_mount_options {
 250         unsigned long s_mount_opt;
 251         uid_t s_resuid;
 252         gid_t s_resgid;
 253         unsigned long s_commit_interval;
 254 #ifdef CONFIG_QUOTA
 255         int s_jquota_fmt;
 256         char *s_qf_names[MAXQUOTAS];
 257 #endif
 258 };
 259
 260 /*
 261  * Structure of an inode on the disk
 262  */
 263 struct ext3_inode {
 264         __le16  i_mode;         /* File mode */
 265         __le16  i_uid;          /* Low 16 bits of Owner Uid */
 266         __le32  i_size;         /* Size in bytes */
 267         __le32  i_atime;        /* Access time */
 268         __le32  i_ctime;        /* Creation time */
 269         __le32  i_mtime;        /* Modification time */
 270         __le32  i_dtime;        /* Deletion Time */
 271         __le16  i_gid;          /* Low 16 bits of Group Id */
 272         __le16  i_links_count;  /* Links count */
 273         __le32  i_blocks;       /* Blocks count */
 274         __le32  i_flags;        /* File flags */
 275         union {
 276                 struct {
 277                         __u32  l_i_reserved1;
 278                 } linux1;
 279                 struct {
 280                         __u32  h_i_translator;
 281                 } hurd1;
 282                 struct {
 283                         __u32  m_i_reserved1;
 284                 } masix1;
 285         } osd1;                         /* OS dependent 1 */
 286         __le32  i_block[EXT3_N_BLOCKS];/* Pointers to blocks */
 287         __le32  i_generation;   /* File version (for NFS) */
 288         __le32  i_file_acl;     /* File ACL */
 289         __le32  i_dir_acl;      /* Directory ACL */
 290         __le32  i_faddr;        /* Fragment address */
 291         union {
 292                 struct {
 293                         __u8    l_i_frag;       /* Fragment number */
 294                         __u8    l_i_fsize;      /* Fragment size */
 295                         __u16   i_pad1;
 296                         __le16  l_i_uid_high;   /* these 2 fields    */
 297                         __le16  l_i_gid_high;   /* were reserved2[0] */
 298                         __u32   l_i_reserved2;
 299                 } linux2;
 300                 struct {
 301                         __u8    h_i_frag;       /* Fragment number */
 302                         __u8    h_i_fsize;      /* Fragment size */
 303                         __u16   h_i_mode_high;
 304                         __u16   h_i_uid_high;
 305                         __u16   h_i_gid_high;
 306                         __u32   h_i_author;
 307                 } hurd2;
 308                 struct {
 309                         __u8    m_i_frag;       /* Fragment number */
 310                         __u8    m_i_fsize;      /* Fragment size */
 311                         __u16   m_pad1;
 312                         __u32   m_i_reserved2[2];
 313                 } masix2;
 314         } osd2;                         /* OS dependent 2 */
 315         __le16  i_extra_isize;
 316         __le16  i_pad1;
 317 };
 318
 319 #define i_size_high     i_dir_acl
 320
 321 #if defined(__KERNEL__) || defined(__linux__)
 322 #define i_reserved1     osd1.linux1.l_i_reserved1
 323 #define i_frag          osd2.linux2.l_i_frag
 324 #define i_fsize         osd2.linux2.l_i_fsize
 325 #define i_uid_low       i_uid
 326 #define i_gid_low       i_gid
 327 #define i_uid_high      osd2.linux2.l_i_uid_high
 328 #define i_gid_high      osd2.linux2.l_i_gid_high
 329 #define i_reserved2     osd2.linux2.l_i_reserved2
 330
 331 #elif defined(__GNU__)
 332
 333 #define i_translator    osd1.hurd1.h_i_translator
 334 #define i_frag          osd2.hurd2.h_i_frag;
 335 #define i_fsize         osd2.hurd2.h_i_fsize;
 336 #define i_uid_high      osd2.hurd2.h_i_uid_high
 337 #define i_gid_high      osd2.hurd2.h_i_gid_high
 338 #define i_author        osd2.hurd2.h_i_author
 339
 340 #elif defined(__masix__)
 341
 342 #define i_reserved1     osd1.masix1.m_i_reserved1
 343 #define i_frag          osd2.masix2.m_i_frag
 344 #define i_fsize         osd2.masix2.m_i_fsize
 345 #define i_reserved2     osd2.masix2.m_i_reserved2
 346
 347 #endif /* defined(__KERNEL__) || defined(__linux__) */
 348
 349 /*
 350  * File system states
 351  */
 352 #define EXT3_VALID_FS                   0x0001  /* Unmounted cleanly */
 353 #define EXT3_ERROR_FS                   0x0002  /* Errors detected */
 354 #define EXT3_ORPHAN_FS                  0x0004  /* Orphans being recovered */
 355
 356 /*
 357  * Mount flags
 358  */
 359 #define EXT3_MOUNT_CHECK                0x00001 /* Do mount-time checks */
 360 #define EXT3_MOUNT_OLDALLOC             0x00002  /* Don't use the new Orlov allocator */
 361 #define EXT3_MOUNT_GRPID                0x00004 /* Create files with directory's group */
 362 #define EXT3_MOUNT_DEBUG                0x00008 /* Some debugging messages */
 363 #define EXT3_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
 364 #define EXT3_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
 365 #define EXT3_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
 366 #define EXT3_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
 367 #define EXT3_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
 368 #define EXT3_MOUNT_ABORT                0x00200 /* Fatal error detected */
 369 #define EXT3_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
 370 #define EXT3_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
 371 #define EXT3_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
 372 #define EXT3_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
 373 #define EXT3_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
 374 #define EXT3_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
 375 #define EXT3_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
 376 #define EXT3_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
 377 #define EXT3_MOUNT_RESERVATION          0x10000 /* Preallocation */
 378 #define EXT3_MOUNT_BARRIER              0x20000 /* Use block barriers */
 379 #define EXT3_MOUNT_NOBH                 0x40000 /* No bufferheads */
 380 #define EXT3_MOUNT_QUOTA                0x80000 /* Some quota option set */
 381 #define EXT3_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
 382 #define EXT3_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
 383 #define EXT3_MOUNT_DATA_ERR_ABORT       0x400000 /* Abort on file data write
 384                                                   * error in ordered mode */
 385
 386 /* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
 387 #ifndef _LINUX_EXT2_FS_H
 388 #define clear_opt(o, opt)               o &= ~EXT3_MOUNT_##opt
 389 #define set_opt(o, opt)                 o |= EXT3_MOUNT_##opt
 390 #define test_opt(sb, opt)               (EXT3_SB(sb)->s_mount_opt & \
 391                                          EXT3_MOUNT_##opt)
 392 #else
 393 #define EXT2_MOUNT_NOLOAD               EXT3_MOUNT_NOLOAD
 394 #define EXT2_MOUNT_ABORT                EXT3_MOUNT_ABORT
 395 #define EXT2_MOUNT_DATA_FLAGS           EXT3_MOUNT_DATA_FLAGS
 396 #endif
 397
 398 #define ext3_set_bit                    ext2_set_bit
 399 #define ext3_set_bit_atomic             ext2_set_bit_atomic
 400 #define ext3_clear_bit                  ext2_clear_bit
 401 #define ext3_clear_bit_atomic           ext2_clear_bit_atomic
 402 #define ext3_test_bit                   ext2_test_bit
 403 #define ext3_find_first_zero_bit        ext2_find_first_zero_bit
 404 #define ext3_find_next_zero_bit         ext2_find_next_zero_bit
 405
 406 /*
 407  * Maximal mount counts between two filesystem checks
 408  */
 409 #define EXT3_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
 410 #define EXT3_DFL_CHECKINTERVAL          0       /* Don't use interval check */
 411
 412 /*
 413  * Behaviour when detecting errors
 414  */
 415 #define EXT3_ERRORS_CONTINUE            1       /* Continue execution */
 416 #define EXT3_ERRORS_RO                  2       /* Remount fs read-only */
 417 #define EXT3_ERRORS_PANIC               3       /* Panic */
 418 #define EXT3_ERRORS_DEFAULT             EXT3_ERRORS_CONTINUE
 419
 420 /*
 421  * Structure of the super block
 422  */
 423 struct ext3_super_block {
 424 /*00*/  __le32  s_inodes_count;         /* Inodes count */
 425         __le32  s_blocks_count;         /* Blocks count */
 426         __le32  s_r_blocks_count;       /* Reserved blocks count */
 427         __le32  s_free_blocks_count;    /* Free blocks count */
 428 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
 429         __le32  s_first_data_block;     /* First Data Block */
 430         __le32  s_log_block_size;       /* Block size */
 431         __le32  s_log_frag_size;        /* Fragment size */
 432 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
 433         __le32  s_frags_per_group;      /* # Fragments per group */
 434         __le32  s_inodes_per_group;     /* # Inodes per group */
 435         __le32  s_mtime;                /* Mount time */
 436 /*30*/  __le32  s_wtime;                /* Write time */
 437         __le16  s_mnt_count;            /* Mount count */
 438         __le16  s_max_mnt_count;        /* Maximal mount count */
 439         __le16  s_magic;                /* Magic signature */
 440         __le16  s_state;                /* File system state */
 441         __le16  s_errors;               /* Behaviour when detecting errors */
 442         __le16  s_minor_rev_level;      /* minor revision level */
 443 /*40*/  __le32  s_lastcheck;            /* time of last check */
 444         __le32  s_checkinterval;        /* max. time between checks */
 445         __le32  s_creator_os;           /* OS */
 446         __le32  s_rev_level;            /* Revision level */
 447 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
 448         __le16  s_def_resgid;           /* Default gid for reserved blocks */
 449         /*
 450          * These fields are for EXT3_DYNAMIC_REV superblocks only.
 451          *
 452          * Note: the difference between the compatible feature set and
 453          * the incompatible feature set is that if there is a bit set
 454          * in the incompatible feature set that the kernel doesn't
 455          * know about, it should refuse to mount the filesystem.
 456          *
 457          * e2fsck's requirements are more strict; if it doesn't know
 458          * about a feature in either the compatible or incompatible
 459          * feature set, it must abort and not try to meddle with
 460          * things it doesn't understand...
 461          */
 462         __le32  s_first_ino;            /* First non-reserved inode */
 463         __le16   s_inode_size;          /* size of inode structure */
 464         __le16  s_block_group_nr;       /* block group # of this superblock */
 465         __le32  s_feature_compat;       /* compatible feature set */
 466 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
 467         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
 468 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
 469 /*78*/  char    s_volume_name[16];      /* volume name */
 470 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
 471 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
 472         /*
 473          * Performance hints.  Directory preallocation should only
 474          * happen if the EXT3_FEATURE_COMPAT_DIR_PREALLOC flag is on.
 475          */
 476         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
 477         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
 478         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
 479         /*
 480          * Journaling support valid if EXT3_FEATURE_COMPAT_HAS_JOURNAL set.
 481          */
 482 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
 483 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
 484         __le32  s_journal_dev;          /* device number of journal file */
 485         __le32  s_last_orphan;          /* start of list of inodes to delete */
 486         __le32  s_hash_seed[4];         /* HTREE hash seed */
 487         __u8    s_def_hash_version;     /* Default hash version to use */
 488         __u8    s_reserved_char_pad;
 489         __u16   s_reserved_word_pad;
 490         __le32  s_default_mount_opts;
 491         __le32  s_first_meta_bg;        /* First metablock block group */
 492         __u32   s_reserved[190];        /* Padding to the end of the block */
 493 };
 494
 495 #ifdef __KERNEL__
 496 #include <linux/ext3_fs_i.h>
 497 #include <linux/ext3_fs_sb.h>
 498 static inline struct ext3_sb_info * EXT3_SB(struct super_block *sb)
 499 {
 500         return sb->s_fs_info;
 501 }
 502 static inline struct ext3_inode_info *EXT3_I(struct inode *inode)
 503 {
 504         return container_of(inode, struct ext3_inode_info, vfs_inode);
 505 }
 506
 507 static inline int ext3_valid_inum(struct super_block *sb, unsigned long ino)
 508 {
 509         return ino == EXT3_ROOT_INO ||
 510                 ino == EXT3_JOURNAL_INO ||
 511                 ino == EXT3_RESIZE_INO ||
 512                 (ino >= EXT3_FIRST_INO(sb) &&
 513                  ino <= le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count));
 514 }
 515 #else
 516 /* Assume that user mode programs are passing in an ext3fs superblock, not
 517  * a kernel struct super_block.  This will allow us to call the feature-test
 518  * macros from user land. */
 519 #define EXT3_SB(sb)     (sb)
 520 #endif
 521
 522 #define NEXT_ORPHAN(inode) EXT3_I(inode)->i_dtime
 523
 524 /*
 525  * Codes for operating systems
 526  */
 527 #define EXT3_OS_LINUX           0
 528 #define EXT3_OS_HURD            1
 529 #define EXT3_OS_MASIX           2
 530 #define EXT3_OS_FREEBSD         3
 531 #define EXT3_OS_LITES           4
 532
 533 /*
 534  * Revision levels
 535  */
 536 #define EXT3_GOOD_OLD_REV       0       /* The good old (original) format */
 537 #define EXT3_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 538
 539 #define EXT3_CURRENT_REV        EXT3_GOOD_OLD_REV
 540 #define EXT3_MAX_SUPP_REV       EXT3_DYNAMIC_REV
 541
 542 #define EXT3_GOOD_OLD_INODE_SIZE 128
 543
 544 /*
 545  * Feature set definitions
 546  */
 547
 548 #define EXT3_HAS_COMPAT_FEATURE(sb,mask)                        \
 549         ( EXT3_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask) )
 550 #define EXT3_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
 551         ( EXT3_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask) )
 552 #define EXT3_HAS_INCOMPAT_FEATURE(sb,mask)                      \
 553         ( EXT3_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask) )
 554 #define EXT3_SET_COMPAT_FEATURE(sb,mask)                        \
 555         EXT3_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
 556 #define EXT3_SET_RO_COMPAT_FEATURE(sb,mask)                     \
 557         EXT3_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
 558 #define EXT3_SET_INCOMPAT_FEATURE(sb,mask)                      \
 559         EXT3_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
 560 #define EXT3_CLEAR_COMPAT_FEATURE(sb,mask)                      \
 561         EXT3_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
 562 #define EXT3_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
 563         EXT3_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
 564 #define EXT3_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
 565         EXT3_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
 566
 567 #define EXT3_FEATURE_COMPAT_DIR_PREALLOC        0x0001
 568 #define EXT3_FEATURE_COMPAT_IMAGIC_INODES       0x0002
 569 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL         0x0004
 570 #define EXT3_FEATURE_COMPAT_EXT_ATTR            0x0008
 571 #define EXT3_FEATURE_COMPAT_RESIZE_INODE        0x0010
 572 #define EXT3_FEATURE_COMPAT_DIR_INDEX           0x0020
 573
 574 #define EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
 575 #define EXT3_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
 576 #define EXT3_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
 577
 578 #define EXT3_FEATURE_INCOMPAT_COMPRESSION       0x0001
 579 #define EXT3_FEATURE_INCOMPAT_FILETYPE          0x0002
 580 #define EXT3_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
 581 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
 582 #define EXT3_FEATURE_INCOMPAT_META_BG           0x0010
 583
 584 #define EXT3_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
 585 #define EXT3_FEATURE_INCOMPAT_SUPP      (EXT3_FEATURE_INCOMPAT_FILETYPE| \
 586                                          EXT3_FEATURE_INCOMPAT_RECOVER| \
 587                                          EXT3_FEATURE_INCOMPAT_META_BG)
 588 #define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 589                                          EXT3_FEATURE_RO_COMPAT_LARGE_FILE| \
 590                                          EXT3_FEATURE_RO_COMPAT_BTREE_DIR)
 591
 592 /*
 593  * Default values for user and/or group using reserved blocks
 594  */
 595 #define EXT3_DEF_RESUID         0
 596 #define EXT3_DEF_RESGID         0
 597
 598 /*
 599  * Default mount options
 600  */
 601 #define EXT3_DEFM_DEBUG         0x0001
 602 #define EXT3_DEFM_BSDGROUPS     0x0002
 603 #define EXT3_DEFM_XATTR_USER    0x0004
 604 #define EXT3_DEFM_ACL           0x0008
 605 #define EXT3_DEFM_UID16         0x0010
 606 #define EXT3_DEFM_JMODE         0x0060
 607 #define EXT3_DEFM_JMODE_DATA    0x0020
 608 #define EXT3_DEFM_JMODE_ORDERED 0x0040
 609 #define EXT3_DEFM_JMODE_WBACK   0x0060
 610
 611 /*
 612  * Structure of a directory entry
 613  */
 614 #define EXT3_NAME_LEN 255
 615
 616 struct ext3_dir_entry {
 617         __le32  inode;                  /* Inode number */
 618         __le16  rec_len;                /* Directory entry length */
 619         __le16  name_len;               /* Name length */
 620         char    name[EXT3_NAME_LEN];    /* File name */
 621 };
 622
 623 /*
 624  * The new version of the directory entry.  Since EXT3 structures are
 625  * stored in intel byte order, and the name_len field could never be
 626  * bigger than 255 chars, it's safe to reclaim the extra byte for the
 627  * file_type field.
 628  */
 629 struct ext3_dir_entry_2 {
 630         __le32  inode;                  /* Inode number */
 631         __le16  rec_len;                /* Directory entry length */
 632         __u8    name_len;               /* Name length */
 633         __u8    file_type;
 634         char    name[EXT3_NAME_LEN];    /* File name */
 635 };
 636
 637 /*
 638  * Ext3 directory file types.  Only the low 3 bits are used.  The
 639  * other bits are reserved for now.
 640  */
 641 #define EXT3_FT_UNKNOWN         0
 642 #define EXT3_FT_REG_FILE        1
 643 #define EXT3_FT_DIR             2
 644 #define EXT3_FT_CHRDEV          3
 645 #define EXT3_FT_BLKDEV          4
 646 #define EXT3_FT_FIFO            5
 647 #define EXT3_FT_SOCK            6
 648 #define EXT3_FT_SYMLINK         7
 649
 650 #define EXT3_FT_MAX             8
 651
 652 /*
 653  * EXT3_DIR_PAD defines the directory entries boundaries
 654  *
 655  * NOTE: It must be a multiple of 4
 656  */
 657 #define EXT3_DIR_PAD                    4
 658 #define EXT3_DIR_ROUND                  (EXT3_DIR_PAD - 1)
 659 #define EXT3_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT3_DIR_ROUND) & \
 660                                          ~EXT3_DIR_ROUND)
 661 #define EXT3_MAX_REC_LEN                ((1<<16)-1)
 662
 663 static inline unsigned ext3_rec_len_from_disk(__le16 dlen)
 664 {
 665         unsigned len = le16_to_cpu(dlen);
 666
 667         if (len == EXT3_MAX_REC_LEN)
 668                 return 1 << 16;
 669         return len;
 670 }
 671
 672 static inline __le16 ext3_rec_len_to_disk(unsigned len)
 673 {
 674         if (len == (1 << 16))
 675                 return cpu_to_le16(EXT3_MAX_REC_LEN);
 676         else if (len > (1 << 16))
 677                 BUG();
 678         return cpu_to_le16(len);
 679 }
 680
 681 /*
 682  * Hash Tree Directory indexing
 683  * (c) Daniel Phillips, 2001
 684  */
 685
 686 #define is_dx(dir) (EXT3_HAS_COMPAT_FEATURE(dir->i_sb, \
 687                                       EXT3_FEATURE_COMPAT_DIR_INDEX) && \
 688                       (EXT3_I(dir)->i_flags & EXT3_INDEX_FL))
 689 #define EXT3_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT3_LINK_MAX)
 690 #define EXT3_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
 691
 692 /* Legal values for the dx_root hash_version field: */
 693
 694 #define DX_HASH_LEGACY          0
 695 #define DX_HASH_HALF_MD4        1
 696 #define DX_HASH_TEA             2
 697
 698 #ifdef __KERNEL__
 699
 700 /* hash info structure used by the directory hash */
 701 struct dx_hash_info
 702 {
 703         u32             hash;
 704         u32             minor_hash;
 705         int             hash_version;
 706         u32             *seed;
 707 };
 708
 709 #define EXT3_HTREE_EOF  0x7fffffff
 710
 711 /*
 712  * Control parameters used by ext3_htree_next_block
 713  */
 714 #define HASH_NB_ALWAYS          1
 715
 716
 717 /*
 718  * Describe an inode's exact location on disk and in memory
 719  */
 720 struct ext3_iloc
 721 {
 722         struct buffer_head *bh;
 723         unsigned long offset;
 724         unsigned long block_group;
 725 };
 726
 727 static inline struct ext3_inode *ext3_raw_inode(struct ext3_iloc *iloc)
 728 {
 729         return (struct ext3_inode *) (iloc->bh->b_data + iloc->offset);
 730 }
 731
 732 /*
 733  * This structure is stuffed into the struct file's private_data field
 734  * for directories.  It is where we put information so that we can do
 735  * readdir operations in hash tree order.
 736  */
 737 struct dir_private_info {
 738         struct rb_root  root;
 739         struct rb_node  *curr_node;
 740         struct fname    *extra_fname;
 741         loff_t          last_pos;
 742         __u32           curr_hash;
 743         __u32           curr_minor_hash;
 744         __u32           next_hash;
 745 };
 746
 747 /* calculate the first block number of the group */
 748 static inline ext3_fsblk_t
 749 ext3_group_first_block_no(struct super_block *sb, unsigned long group_no)
 750 {
 751         return group_no * (ext3_fsblk_t)EXT3_BLOCKS_PER_GROUP(sb) +
 752                 le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block);
 753 }
 754
 755 /*
 756  * Special error return code only used by dx_probe() and its callers.
 757  */
 758 #define ERR_BAD_DX_DIR  -75000
 759
 760 /*
 761  * Function prototypes
 762  */
 763
 764 /*
 765  * Ok, these declarations are also in <linux/kernel.h> but none of the
 766  * ext3 source programs needs to include it so they are duplicated here.
 767  */
 768 # define NORET_TYPE    /**/
 769 # define ATTRIB_NORET  __attribute__((noreturn))
 770 # define NORET_AND     noreturn,
 771
 772 /* balloc.c */
 773 extern int ext3_bg_has_super(struct super_block *sb, int group);
 774 extern unsigned long ext3_bg_num_gdb(struct super_block *sb, int group);
 775 extern ext3_fsblk_t ext3_new_block (handle_t *handle, struct inode *inode,
 776                         ext3_fsblk_t goal, int *errp);
 777 extern ext3_fsblk_t ext3_new_blocks (handle_t *handle, struct inode *inode,
 778                         ext3_fsblk_t goal, unsigned long *count, int *errp);
 779 extern void ext3_free_blocks (handle_t *handle, struct inode *inode,
 780                         ext3_fsblk_t block, unsigned long count);
 781 extern void ext3_free_blocks_sb (handle_t *handle, struct super_block *sb,
 782                                  ext3_fsblk_t block, unsigned long count,
 783                                 unsigned long *pdquot_freed_blocks);
 784 extern ext3_fsblk_t ext3_count_free_blocks (struct super_block *);
 785 extern void ext3_check_blocks_bitmap (struct super_block *);
 786 extern struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb,
 787                                                     unsigned int block_group,
 788                                                     struct buffer_head ** bh);
 789 extern int ext3_should_retry_alloc(struct super_block *sb, int *retries);
 790 extern void ext3_init_block_alloc_info(struct inode *);
 791 extern void ext3_rsv_window_add(struct super_block *sb, struct ext3_reserve_window_node *rsv);
 792
 793 /* dir.c */
 794 extern int ext3_check_dir_entry(const char *, struct inode *,
 795                                 struct ext3_dir_entry_2 *,
 796                                 struct buffer_head *, unsigned long);
 797 extern int ext3_htree_store_dirent(struct file *dir_file, __u32 hash,
 798                                     __u32 minor_hash,
 799                                     struct ext3_dir_entry_2 *dirent);
 800 extern void ext3_htree_free_dir_info(struct dir_private_info *p);
 801
 802 /* fsync.c */
 803 extern int ext3_sync_file (struct file *, struct dentry *, int);
 804
 805 /* hash.c */
 806 extern int ext3fs_dirhash(const char *name, int len, struct
 807                           dx_hash_info *hinfo);
 808
 809 /* ialloc.c */
 810 extern struct inode * ext3_new_inode (handle_t *, struct inode *, int);
 811 extern void ext3_free_inode (handle_t *, struct inode *);
 812 extern struct inode * ext3_orphan_get (struct super_block *, unsigned long);
 813 extern unsigned long ext3_count_free_inodes (struct super_block *);
 814 extern unsigned long ext3_count_dirs (struct super_block *);
 815 extern void ext3_check_inodes_bitmap (struct super_block *);
 816 extern unsigned long ext3_count_free (struct buffer_head *, unsigned);
 817
 818
 819 /* inode.c */
 820 int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
 821                 struct buffer_head *bh, ext3_fsblk_t blocknr);
 822 struct buffer_head * ext3_getblk (handle_t *, struct inode *, long, int, int *);
 823 struct buffer_head * ext3_bread (handle_t *, struct inode *, int, int, int *);
 824 int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
 825         sector_t iblock, unsigned long maxblocks, struct buffer_head *bh_result,
 826         int create, int extend_disksize);
 827
 828 extern struct inode *ext3_iget(struct super_block *, unsigned long);
 829 extern int  ext3_write_inode (struct inode *, int);
 830 extern int  ext3_setattr (struct dentry *, struct iattr *);
 831 extern void ext3_delete_inode (struct inode *);
 832 extern int  ext3_sync_inode (handle_t *, struct inode *);
 833 extern void ext3_discard_reservation (struct inode *);
 834 extern void ext3_dirty_inode(struct inode *);
 835 extern int ext3_change_inode_journal_flag(struct inode *, int);
 836 extern int ext3_get_inode_loc(struct inode *, struct ext3_iloc *);
 837 extern int ext3_can_truncate(struct inode *inode);
 838 extern void ext3_truncate (struct inode *);
 839 extern void ext3_set_inode_flags(struct inode *);
 840 extern void ext3_get_inode_flags(struct ext3_inode_info *);
 841 extern void ext3_set_aops(struct inode *inode);
 842 extern int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 843                        u64 start, u64 len);
 844
 845 /* ioctl.c */
 846 extern int ext3_ioctl (struct inode *, struct file *, unsigned int,
 847                        unsigned long);
 848 extern long ext3_compat_ioctl (struct file *, unsigned int, unsigned long);
 849
 850 /* namei.c */
 851 extern int ext3_orphan_add(handle_t *, struct inode *);
 852 extern int ext3_orphan_del(handle_t *, struct inode *);
 853 extern int ext3_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 854                                 __u32 start_minor_hash, __u32 *next_hash);
 855
 856 /* resize.c */
 857 extern int ext3_group_add(struct super_block *sb,
 858                                 struct ext3_new_group_data *input);
 859 extern int ext3_group_extend(struct super_block *sb,
 860                                 struct ext3_super_block *es,
 861                                 ext3_fsblk_t n_blocks_count);
 862
 863 /* super.c */
 864 extern void ext3_error (struct super_block *, const char *, const char *, ...)
 865         __attribute__ ((format (printf, 3, 4)));
 866 extern void __ext3_std_error (struct super_block *, const char *, int);
 867 extern void ext3_abort (struct super_block *, const char *, const char *, ...)
 868         __attribute__ ((format (printf, 3, 4)));
 869 extern void ext3_warning (struct super_block *, const char *, const char *, ...)
 870         __attribute__ ((format (printf, 3, 4)));
 871 extern void ext3_update_dynamic_rev (struct super_block *sb);
 872
 873 #define ext3_std_error(sb, errno)                               \
 874 do {                                                            \
 875         if ((errno))                                            \
 876                 __ext3_std_error((sb), __func__, (errno));      \
 877 } while (0)
 878
 879 /*
 880  * Inodes and files operations
 881  */
 882
 883 /* dir.c */
 884 extern const struct file_operations ext3_dir_operations;
 885
 886 /* file.c */
 887 extern const struct inode_operations ext3_file_inode_operations;
 888 extern const struct file_operations ext3_file_operations;
 889
 890 /* namei.c */
 891 extern const struct inode_operations ext3_dir_inode_operations;
 892 extern const struct inode_operations ext3_special_inode_operations;
 893
 894 /* symlink.c */
 895 extern const struct inode_operations ext3_symlink_inode_operations;
 896 extern const struct inode_operations ext3_fast_symlink_inode_operations;
 897
 898
 899 #endif  /* __KERNEL__ */
 900
 901 #endif  /* _LINUX_EXT3_FS_H */