servers/ext2/const.h

   1 #ifndef EXT2_CONST_H
   2 #define EXT2_CONST_H
   3
   4 /* Tables sizes */
   5
   6 #define NR_INODES        512    /* # slots in "in core" inode table;
   7                                  * should be more or less the same as
   8                                  * NR_VNODES in vfs
   9                                  */
  10 #define GETDENTS_BUFSIZ  257
  11
  12 #define INODE_HASH_LOG2   7     /* 2 based logarithm of the inode hash size */
  13 #define INODE_HASH_SIZE   ((unsigned long)1<<INODE_HASH_LOG2)
  14 #define INODE_HASH_MASK   (((unsigned long)1<<INODE_HASH_LOG2)-1)
  15
  16
  17 /* The type of sizeof may be (unsigned) long.  Use the following macro for
  18  * taking the sizes of small objects so that there are no surprises like
  19  * (small) long constants being passed to routines expecting an int.
  20  */
  21 #define usizeof(t) ((unsigned) sizeof(t))
  22
  23 #define SUPER_MAGIC   0xEF53  /* magic number contained in super-block */
  24
  25 #define EXT2_NAME_MAX   255
  26
  27 /* Miscellaneous constants */
  28 #define SU_UID          ((uid_t) 0)     /* super_user's uid_t */
  29 #define NORMAL          0               /* forces get_block to do disk read */
  30 #define NO_READ         1       /* prevents get_block from doing disk read */
  31 #define PREFETCH        2       /* tells get_block not to read or mark dev */
  32
  33 #define NO_BIT   ((bit_t) 0)    /* returned by alloc_bit() to signal failure */
  34
  35 #define LOOK_UP            0 /* tells search_dir to lookup string */
  36 #define ENTER              1 /* tells search_dir to make dir entry */
  37 #define DELETE             2 /* tells search_dir to delete entry */
  38 #define IS_EMPTY           3 /* tells search_dir to ret. OK or ENOTEMPTY */
  39
  40 /* write_map() args */
  41 #define WMAP_FREE           (1 << 0)
  42
  43 #define IGN_PERM            0
  44 #define CHK_PERM            1
  45
  46 #define IN_CLEAN              0    /* inode disk and memory copies identical */
  47 #define IN_DIRTY              1    /* inode disk and memory copies differ */
  48 #define ATIME            002    /* set if atime field needs updating */
  49 #define CTIME            004    /* set if ctime field needs updating */
  50 #define MTIME            010    /* set if mtime field needs updating */
  51
  52 #define BYTE_SWAP          0    /* tells conv2/conv4 to swap bytes */
  53
  54 #define END_OF_FILE   (-104)    /* eof detected */
  55
  56 #define SUPER_BLOCK_BYTES       (1024)         /* bytes offset */
  57
  58 #define ROOT_INODE      ((ino_t) 2)   /* inode number for root directory */
  59 #define BOOT_BLOCK      ((block_t) 0) /* block number of boot block */
  60 #define START_BLOCK     ((block_t) 2) /* first block of FS (not counting SB) */
  61 #define BLOCK_ADDRESS_BYTES     4     /* bytes per address */
  62
  63 #define SUPER_SIZE      usizeof (struct super_block) /* sb size in RAM */
  64 #define SUPER_SIZE_D    (1024)  /* max size of superblock stored on disk */
  65
  66 /* Directories related macroses */
  67
  68 #define DIR_ENTRY_ALIGN         4
  69
  70 /* ino + rec_len + name_len + file_type, doesn't include name and padding */
  71 #define MIN_DIR_ENTRY_SIZE      8
  72
  73 #define DIR_ENTRY_CONTENTS_SIZE(d) (MIN_DIR_ENTRY_SIZE + (d)->d_name_len)
  74
  75 /* size with padding */
  76 #define DIR_ENTRY_ACTUAL_SIZE(d) (DIR_ENTRY_CONTENTS_SIZE(d) + \
  77         ((DIR_ENTRY_CONTENTS_SIZE(d) & 0x03) == 0 ? 0 : \
  78                         DIR_ENTRY_ALIGN - (DIR_ENTRY_CONTENTS_SIZE(d) & 0x03) ))
  79
  80 /* How many bytes can be taken from the end of dentry */
  81 #define DIR_ENTRY_SHRINK(d)    (conv2(le_CPU, (d)->d_rec_len) \
  82                                         - DIR_ENTRY_ACTUAL_SIZE(d))
  83
  84 /* Dentry can have padding, which can be used to enlarge namelen */
  85 #define DIR_ENTRY_MAX_NAME_LEN(d)       (conv2(le_CPU, (d)->d_rec_len) \
  86                                                 - MIN_DIR_ENTRY_SIZE)
  87
  88 /* Constants relative to the data blocks */
  89 /* When change EXT2_NDIR_BLOCKS, modify ext2_max_size()!!!*/
  90 #define EXT2_NDIR_BLOCKS        12
  91 #define EXT2_IND_BLOCK          EXT2_NDIR_BLOCKS
  92 #define EXT2_DIND_BLOCK         (EXT2_IND_BLOCK + 1)
  93 #define EXT2_TIND_BLOCK         (EXT2_DIND_BLOCK + 1)
  94 #define EXT2_N_BLOCKS           (EXT2_TIND_BLOCK + 1)
  95
  96 #define FS_BITMAP_CHUNKS(b) ((b)/usizeof (bitchunk_t))/* # map chunks/blk   */
  97 #define FS_BITCHUNK_BITS        (usizeof(bitchunk_t) * CHAR_BIT)
  98 #define FS_BITS_PER_BLOCK(b)    (FS_BITMAP_CHUNKS(b) * FS_BITCHUNK_BITS)
  99
 100 /* Inodes */
 101
 102 /* Next 4 following macroses were taken from linux' ext2_fs.h */
 103 #define EXT2_GOOD_OLD_INODE_SIZE        128
 104 #define EXT2_GOOD_OLD_FIRST_INO         11
 105
 106 #define EXT2_INODE_SIZE(s)      (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
 107                                 EXT2_GOOD_OLD_INODE_SIZE : \
 108                                                         (s)->s_inode_size)
 109 #define EXT2_FIRST_INO(s)       (((s)->s_rev_level == EXT2_GOOD_OLD_REV) ? \
 110                                 EXT2_GOOD_OLD_FIRST_INO : \
 111                                                         (s)->s_first_ino)
 112
 113 /* Maximum size of a fast symlink including trailing '\0' */
 114 #define MAX_FAST_SYMLINK_LENGTH \
 115         ( sizeof(((d_inode *)0)->i_block[0]) * EXT2_N_BLOCKS )
 116
 117 #define NUL(str,l,m) mfs_nul_f(__FILE__,__LINE__,(str), (l), (m))
 118
 119 /* FS states */
 120 #define EXT2_VALID_FS                   0x0001  /* Cleanly unmounted */
 121 #define EXT2_ERROR_FS                   0x0002  /* Errors detected */
 122
 123 #define EXT2_GOOD_OLD_REV       0       /* The good old (original) format */
 124 #define EXT2_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
 125
 126 /* ext2 features, names shorted (cut EXT2_ prefix) */
 127 #define COMPAT_DIR_PREALLOC        0x0001
 128 #define COMPAT_IMAGIC_INODES       0x0002
 129 #define COMPAT_HAS_JOURNAL         0x0004
 130 #define COMPAT_EXT_ATTR            0x0008
 131 #define COMPAT_RESIZE_INO          0x0010
 132 #define COMPAT_DIR_INDEX           0x0020
 133 #define COMPAT_ANY                 0xffffffff
 134
 135 #define RO_COMPAT_SPARSE_SUPER     0x0001
 136 #define RO_COMPAT_LARGE_FILE       0x0002
 137 #define RO_COMPAT_BTREE_DIR        0x0004
 138 #define RO_COMPAT_ANY              0xffffffff
 139
 140 #define INCOMPAT_COMPRESSION       0x0001
 141 #define INCOMPAT_FILETYPE          0x0002
 142 #define INCOMPAT_RECOVER           0x0004
 143 #define INCOMPAT_JOURNAL_DEV       0x0008
 144 #define INCOMPAT_META_BG           0x0010
 145 #define INCOMPAT_ANY               0xffffffff
 146
 147 /* What do we support? */
 148 #define SUPPORTED_INCOMPAT_FEATURES     (INCOMPAT_FILETYPE)
 149 #define SUPPORTED_RO_COMPAT_FEATURES    (RO_COMPAT_SPARSE_SUPER | \
 150                                          RO_COMPAT_LARGE_FILE)
 151
 152 /* Ext2 directory file types. Only the low 3 bits are used.
 153  * The other bits are reserved for now.
 154  */
 155 #define EXT2_FT_UNKNOWN         0
 156 #define EXT2_FT_REG_FILE        1
 157 #define EXT2_FT_DIR             2
 158 #define EXT2_FT_CHRDEV          3
 159 #define EXT2_FT_BLKDEV          4
 160 #define EXT2_FT_FIFO            5
 161 #define EXT2_FT_SOCK            6
 162 #define EXT2_FT_SYMLINK         7
 163
 164 #define EXT2_FT_MAX             8
 165
 166 #define HAS_COMPAT_FEATURE(sp, mask)                        \
 167         ( (sp)->s_feature_compat & (mask) )
 168 #define HAS_RO_COMPAT_FEATURE(sp, mask)                     \
 169         ( (sp)->s_feature_ro_compat & (mask) )
 170 #define HAS_INCOMPAT_FEATURE(sp, mask)                      \
 171         ( (sp)->s_feature_incompat & (mask) )
 172
 173
 174 /* hash-indexed directory */
 175 #define EXT2_INDEX_FL                   0x00001000
 176 /* Top of directory hierarchies*/
 177 #define EXT2_TOPDIR_FL                  0x00020000
 178
 179 #define EXT2_PREALLOC_BLOCKS            8
 180
 181
 182 #endif /* EXT2_CONST_H */