fs/ufs/util.h

   1 /*
   2  *  linux/fs/ufs/util.h
   3  *
   4  * Copyright (C) 1998
   5  * Daniel Pirkl <daniel.pirkl@email.cz>
   6  * Charles University, Faculty of Mathematics and Physics
   7  */
   8
   9 #include <linux/fs.h>
  10 #include "swab.h"
  11
  12
  13 /*
  14  * some useful macros
  15  */
  16 #define in_range(b,first,len)   ((b)>=(first)&&(b)<(first)+(len))
  17 #define min(x,y)                ((x)<(y)?(x):(y))
  18 #define max(x,y)                ((x)>(y)?(x):(y))
  19
  20
  21
  22 /*
  23  * macros used for retyping
  24  */
  25 #define UCPI_UBH ((struct ufs_buffer_head *)ucpi)
  26 #define USPI_UBH ((struct ufs_buffer_head *)uspi)
  27
  28
  29
  30 /*
  31  * macros used for accesing structures
  32  */
  33 #define ufs_get_fs_state(usb1,usb3) _ufs_get_fs_state_(usb1,usb3,flags,swab)
  34 static inline __s32 _ufs_get_fs_state_(struct ufs_super_block_first * usb1,
  35         struct ufs_super_block_third * usb3, unsigned flags, unsigned swab)
  36 {
  37         switch (flags & UFS_ST_MASK) {
  38                 case UFS_ST_SUN:
  39                         return SWAB32((usb3)->fs_u2.fs_sun.fs_state);
  40                 case UFS_ST_SUNx86:
  41                         return SWAB32((usb1)->fs_u1.fs_sunx86.fs_state);
  42                 case UFS_ST_44BSD:
  43                 default:
  44                         return SWAB32((usb3)->fs_u2.fs_44.fs_state);
  45         }
  46 }
  47
  48 #define ufs_set_fs_state(usb1,usb3,value) _ufs_set_fs_state_(usb1,usb3,value,flags,swab)
  49 static inline void _ufs_set_fs_state_(struct ufs_super_block_first * usb1,
  50         struct ufs_super_block_third * usb3, __s32 value, unsigned flags, unsigned swab)
  51 {
  52         switch (flags & UFS_ST_MASK) {
  53                 case UFS_ST_SUN:
  54                         (usb3)->fs_u2.fs_sun.fs_state = SWAB32(value);
  55                         break;
  56                 case UFS_ST_SUNx86:
  57                         (usb1)->fs_u1.fs_sunx86.fs_state = SWAB32(value);
  58                         break;
  59                 case UFS_ST_44BSD:
  60                         (usb3)->fs_u2.fs_44.fs_state = SWAB32(value);
  61                         break;
  62         }
  63 }
  64
  65 #define ufs_get_fs_npsect(usb1,usb3) _ufs_get_fs_npsect_(usb1,usb3,flags,swab)
  66 static inline __u32 _ufs_get_fs_npsect_(struct ufs_super_block_first * usb1,
  67         struct ufs_super_block_third * usb3, unsigned flags, unsigned swab)
  68 {
  69         if ((flags & UFS_ST_MASK) == UFS_ST_SUNx86)
  70                 return SWAB32((usb3)->fs_u2.fs_sunx86.fs_npsect);
  71         else
  72                 return SWAB32((usb1)->fs_u1.fs_sun.fs_npsect);
  73 }
  74
  75 #define ufs_get_fs_qbmask(usb3) _ufs_get_fs_qbmask_(usb3,flags,swab)
  76 static inline __u64 _ufs_get_fs_qbmask_(struct ufs_super_block_third * usb3,
  77         unsigned flags, unsigned swab)
  78 {
  79         __u64 tmp;
  80         switch (flags & UFS_ST_MASK) {
  81                 case UFS_ST_SUN:
  82                         ((u32 *)&tmp)[0] = usb3->fs_u2.fs_sun.fs_qbmask[0];
  83                         ((u32 *)&tmp)[1] = usb3->fs_u2.fs_sun.fs_qbmask[1];
  84                         break;
  85                 case UFS_ST_SUNx86:
  86                         ((u32 *)&tmp)[0] = usb3->fs_u2.fs_sunx86.fs_qbmask[0];
  87                         ((u32 *)&tmp)[1] = usb3->fs_u2.fs_sunx86.fs_qbmask[1];
  88                         break;
  89                 case UFS_ST_44BSD:
  90                         ((u32 *)&tmp)[0] = usb3->fs_u2.fs_44.fs_qbmask[0];
  91                         ((u32 *)&tmp)[1] = usb3->fs_u2.fs_44.fs_qbmask[1];
  92                         break;
  93         }
  94         return SWAB64(tmp);
  95 }
  96
  97 #define ufs_get_fs_qfmask(usb3) _ufs_get_fs_qfmask_(usb3,flags,swab)
  98 static inline __u64 _ufs_get_fs_qfmask_(struct ufs_super_block_third * usb3,
  99         unsigned flags, unsigned swab)
 100 {
 101         __u64 tmp;
 102         switch (flags & UFS_ST_MASK) {
 103                 case UFS_ST_SUN:
 104                         ((u32 *)&tmp)[0] = usb3->fs_u2.fs_sun.fs_qfmask[0];
 105                         ((u32 *)&tmp)[1] = usb3->fs_u2.fs_sun.fs_qfmask[1];
 106                         break;
 107                 case UFS_ST_SUNx86:
 108                         ((u32 *)&tmp)[0] = usb3->fs_u2.fs_sunx86.fs_qfmask[0];
 109                         ((u32 *)&tmp)[1] = usb3->fs_u2.fs_sunx86.fs_qfmask[1];
 110                         break;
 111                 case UFS_ST_44BSD:
 112                         ((u32 *)&tmp)[0] = usb3->fs_u2.fs_44.fs_qfmask[0];
 113                         ((u32 *)&tmp)[1] = usb3->fs_u2.fs_44.fs_qfmask[1];
 114                         break;
 115         }
 116         return SWAB64(tmp);
 117 }
 118
 119 #define ufs_get_de_namlen(de) \
 120         (((flags & UFS_DE_MASK) == UFS_DE_OLD) \
 121         ? SWAB16(de->d_u.d_namlen) \
 122         : de->d_u.d_44.d_namlen)
 123
 124 #define ufs_set_de_namlen(de,value) \
 125         (((flags & UFS_DE_MASK) == UFS_DE_OLD) \
 126         ? (de->d_u.d_namlen = SWAB16(value)) \
 127         : (de->d_u.d_44.d_namlen = value))
 128
 129 #define ufs_set_de_type(de,mode) _ufs_set_de_type_(de,mode,flags,swab)
 130 static inline void _ufs_set_de_type_(struct ufs_dir_entry * de, int mode,
 131         unsigned flags, unsigned swab)
 132 {
 133         if ((flags & UFS_DE_MASK) == UFS_DE_44BSD) {
 134                 switch (mode & S_IFMT) {
 135                         case S_IFSOCK: de->d_u.d_44.d_type = DT_SOCK; break;
 136                         case S_IFLNK: de->d_u.d_44.d_type = DT_LNK; break;
 137                         case S_IFREG: de->d_u.d_44.d_type = DT_REG; break;
 138                         case S_IFBLK: de->d_u.d_44.d_type = DT_BLK; break;
 139                         case S_IFDIR: de->d_u.d_44.d_type = DT_DIR; break;
 140                         case S_IFCHR: de->d_u.d_44.d_type = DT_CHR; break;
 141                         case S_IFIFO: de->d_u.d_44.d_type = DT_FIFO; break;
 142                         default: de->d_u.d_44.d_type = DT_UNKNOWN;
 143                 }
 144         }
 145 }
 146
 147 #define ufs_get_inode_uid(inode) _ufs_get_inode_uid_(inode,flags,swab)
 148 static inline __u32 _ufs_get_inode_uid_(struct ufs_inode * inode,
 149         unsigned flags, unsigned swab)
 150 {
 151         switch (flags & UFS_UID_MASK) {
 152                 case UFS_UID_EFT:
 153                         return SWAB32(inode->ui_u3.ui_sun.ui_uid);
 154                 case UFS_UID_44BSD:
 155                         return SWAB32(inode->ui_u3.ui_44.ui_uid);
 156                 default:
 157                         return SWAB16(inode->ui_u1.oldids.ui_suid);
 158         }
 159 }
 160
 161 #define ufs_set_inode_uid(inode,value) _ufs_set_inode_uid_(inode,value,flags,swab)
 162 static inline void _ufs_set_inode_uid_(struct ufs_inode * inode, __u32 value,
 163         unsigned flags, unsigned swab)
 164 {
 165         inode->ui_u1.oldids.ui_suid = SWAB16(value);
 166         switch (flags & UFS_UID_MASK) {
 167                 case UFS_UID_EFT:
 168                         inode->ui_u3.ui_sun.ui_uid = SWAB32(value);
 169                         break;
 170                 case UFS_UID_44BSD:
 171                         inode->ui_u3.ui_44.ui_uid = SWAB32(value);
 172                         break;
 173         }
 174 }
 175
 176 #define ufs_get_inode_gid(inode) _ufs_get_inode_gid_(inode,flags,swab)
 177 static inline __u32 _ufs_get_inode_gid_(struct ufs_inode * inode,
 178         unsigned flags, unsigned swab)
 179 {
 180         switch (flags & UFS_UID_MASK) {
 181                 case UFS_UID_EFT:
 182                         return SWAB32(inode->ui_u3.ui_sun.ui_gid);
 183                 case UFS_UID_44BSD:
 184                         return SWAB32(inode->ui_u3.ui_44.ui_gid);
 185                 default:
 186                         return SWAB16(inode->ui_u1.oldids.ui_sgid);
 187         }
 188 }
 189
 190 #define ufs_set_inode_gid(inode,value) _ufs_set_inode_gid_(inode,value,flags,swab)
 191 static inline void _ufs_set_inode_gid_(struct ufs_inode * inode, __u32 value,
 192         unsigned flags, unsigned swab)
 193 {
 194         inode->ui_u1.oldids.ui_sgid =  SWAB16(value);
 195         switch (flags & UFS_UID_MASK) {
 196                 case UFS_UID_EFT:
 197                         inode->ui_u3.ui_sun.ui_gid = SWAB32(value);
 198                         break;
 199                 case UFS_UID_44BSD:
 200                         inode->ui_u3.ui_44.ui_gid = SWAB32(value);
 201                         break;
 202         }
 203 }
 204
 205
 206
 207 /*
 208  * These functions manipulate ufs buffers
 209  */
 210 #define ubh_bread(dev,fragment,size) _ubh_bread_(uspi,dev,fragment,size)
 211 extern struct ufs_buffer_head * _ubh_bread_(struct ufs_sb_private_info *, kdev_t, unsigned, unsigned);
 212 extern struct ufs_buffer_head * ubh_bread_uspi(struct ufs_sb_private_info *, kdev_t, unsigned, unsigned);
 213 extern void ubh_brelse (struct ufs_buffer_head *);
 214 extern void ubh_brelse_uspi (struct ufs_sb_private_info *);
 215 extern void ubh_mark_buffer_dirty (struct ufs_buffer_head *);
 216 extern void ubh_mark_buffer_uptodate (struct ufs_buffer_head *, int);
 217 extern void ubh_ll_rw_block (int, unsigned, struct ufs_buffer_head **);
 218 extern void ubh_wait_on_buffer (struct ufs_buffer_head *);
 219 extern unsigned ubh_max_bcount (struct ufs_buffer_head *);
 220 extern void ubh_bforget (struct ufs_buffer_head *);
 221 extern int  ubh_buffer_dirty (struct ufs_buffer_head *);
 222 #define ubh_ubhcpymem(mem,ubh,size) _ubh_ubhcpymem_(uspi,mem,ubh,size)
 223 extern void _ubh_ubhcpymem_(struct ufs_sb_private_info *, unsigned char *, struct ufs_buffer_head *, unsigned);
 224 #define ubh_memcpyubh(ubh,mem,size) _ubh_memcpyubh_(uspi,ubh,mem,size)
 225 extern void _ubh_memcpyubh_(struct ufs_sb_private_info *, struct ufs_buffer_head *, unsigned char *, unsigned);
 226
 227
 228
 229 /*
 230  * macros to get important structures from ufs_buffer_head
 231  */
 232 #define ubh_get_usb_first(ubh) \
 233         ((struct ufs_super_block_first *)((ubh)->bh[0]->b_data))
 234
 235 #define ubh_get_usb_second(ubh) \
 236         ((struct ufs_super_block_second *)(ubh)-> \
 237         bh[UFS_SECTOR_SIZE >> uspi->s_fshift]->b_data + (UFS_SECTOR_SIZE & ~uspi->s_fmask))
 238
 239 #define ubh_get_usb_third(ubh) \
 240         ((struct ufs_super_block_third *)((ubh)-> \
 241         bh[UFS_SECTOR_SIZE*2 >> uspi->s_fshift]->b_data + (UFS_SECTOR_SIZE*2 & ~uspi->s_fmask)))
 242
 243 #define ubh_get_ucg(ubh) \
 244         ((struct ufs_cylinder_group *)((ubh)->bh[0]->b_data))
 245
 246
 247 /*
 248  * Extract byte from ufs_buffer_head
 249  * Extract the bits for a block from a map inside ufs_buffer_head
 250  */
 251 #define ubh_get_addr8(ubh,begin) \
 252         ((u8*)(ubh)->bh[(begin) >> uspi->s_fshift]->b_data + \
 253         ((begin) & ~uspi->s_fmask))
 254
 255 #define ubh_get_addr16(ubh,begin) \
 256         (((u16*)((ubh)->bh[(begin) >> (uspi->s_fshift-1)]->b_data)) + \
 257         ((begin) & (uspi->fsize>>1) - 1)))
 258
 259 #define ubh_get_addr32(ubh,begin) \
 260         (((u32*)((ubh)->bh[(begin) >> (uspi->s_fshift-2)]->b_data)) + \
 261         ((begin) & ((uspi->s_fsize>>2) - 1)))
 262
 263 #define ubh_get_addr ubh_get_addr8
 264
 265 #define ubh_blkmap(ubh,begin,bit) \
 266         ((*ubh_get_addr(ubh, (begin) + ((bit) >> 3)) >> ((bit) & 7)) & (0xff >> (UFS_MAXFRAG - uspi->s_fpb)))
 267
 268
 269 /*
 270  * Macros for access to superblock array structures
 271  */
 272 #define ubh_postbl(ubh,cylno,i) \
 273         ((uspi->s_postblformat != UFS_DYNAMICPOSTBLFMT) \
 274         ? (*(__s16*)(ubh_get_addr(ubh, \
 275         (unsigned)(&((struct ufs_super_block *)0)->fs_opostbl) \
 276         + (((cylno) * 16 + (i)) << 1) ) )) \
 277         : (*(__s16*)(ubh_get_addr(ubh, \
 278         uspi->s_postbloff + (((cylno) * uspi->s_nrpos + (i)) << 1) ))))
 279
 280 #define ubh_rotbl(ubh,i) \
 281         ((uspi->s_postblformat != UFS_DYNAMICPOSTBLFMT) \
 282         ? (*(__u8*)(ubh_get_addr(ubh, \
 283         (unsigned)(&((struct ufs_super_block *)0)->fs_space) + (i)))) \
 284         : (*(__u8*)(ubh_get_addr(ubh, uspi->s_rotbloff + (i)))))
 285
 286 /*
 287  * Determine the number of available frags given a
 288  * percentage to hold in reserve.
 289  */
 290 #define ufs_freespace(usb, percentreserved) \
 291         (ufs_blkstofrags(SWAB32((usb)->fs_cstotal.cs_nbfree)) + \
 292         SWAB32((usb)->fs_cstotal.cs_nffree) - (uspi->s_dsize * (percentreserved) / 100))
 293
 294 /*
 295  * Macros to access cylinder group array structures
 296  */
 297 #define ubh_cg_blktot(ucpi,cylno) \
 298         (*((__u32*)ubh_get_addr(UCPI_UBH, (ucpi)->c_btotoff + ((cylno) << 2))))
 299
 300 #define ubh_cg_blks(ucpi,cylno,rpos) \
 301         (*((__u16*)ubh_get_addr(UCPI_UBH, \
 302         (ucpi)->c_boff + (((cylno) * uspi->s_nrpos + (rpos)) << 1 ))))
 303
 304 /*
 305  * Bitmap operations
 306  * These functions work like classical bitmap operations.
 307  * The difference is that we don't have the whole bitmap
 308  * in one contiguous chunk of memory, but in several buffers.
 309  * The parameters of each function are super_block, ufs_buffer_head and
 310  * position of the beginning of the bitmap.
 311  */
 312 #define ubh_setbit(ubh,begin,bit) \
 313         (*ubh_get_addr(ubh, (begin) + ((bit) >> 3)) |= (1 << ((bit) & 7)))
 314
 315 #define ubh_clrbit(ubh,begin,bit) \
 316         (*ubh_get_addr (ubh, (begin) + ((bit) >> 3)) &= ~(1 << ((bit) & 7)))
 317
 318 #define ubh_isset(ubh,begin,bit) \
 319         (*ubh_get_addr (ubh, (begin) + ((bit) >> 3)) & (1 << ((bit) & 7)))
 320
 321 #define ubh_isclr(ubh,begin,bit) (!ubh_isset(ubh,begin,bit))
 322
 323 #define ubh_find_first_zero_bit(ubh,begin,size) _ubh_find_next_zero_bit_(uspi,ubh,begin,size,0)
 324
 325 #define ubh_find_next_zero_bit(ubh,begin,size,offset) _ubh_find_next_zero_bit_(uspi,ubh,begin,size,offset)
 326 static inline unsigned _ubh_find_next_zero_bit_(
 327         struct ufs_sb_private_info * uspi, struct ufs_buffer_head * ubh,
 328         unsigned begin, unsigned size, unsigned offset)
 329 {
 330         unsigned base, count, pos;
 331
 332         size -= offset;
 333         begin <<= 3;
 334         offset += begin;
 335         base = offset >> uspi->s_bpfshift;
 336         offset &= uspi->s_bpfmask;
 337         for (;;) {
 338                 count = min (size + offset, uspi->s_bpf);
 339                 size -= count - offset;
 340                 pos = ext2_find_next_zero_bit (ubh->bh[base]->b_data, count, offset);
 341                 if (pos < count || !size)
 342                         break;
 343                 base++;
 344                 offset = 0;
 345         }
 346         return (base << uspi->s_bpfshift) + pos - begin;
 347 }
 348
 349 static inline unsigned find_last_zero_bit (unsigned char * bitmap,
 350         unsigned size, unsigned offset)
 351 {
 352         unsigned bit, i;
 353         unsigned char * mapp;
 354         unsigned char map;
 355
 356         mapp = bitmap + (size >> 3);
 357         map = *mapp--;
 358         bit = 1 << (size & 7);
 359         for (i = size; i > offset; i--) {
 360                 if ((map & bit) == 0)
 361                         break;
 362                 if ((i & 7) != 0) {
 363                         bit >>= 1;
 364                 } else {
 365                         map = *mapp--;
 366                         bit = 1 << 7;
 367                 }
 368         }
 369         return i;
 370 }
 371
 372 #define ubh_find_last_zero_bit(ubh,begin,size,offset) _ubh_find_last_zero_bit_(uspi,ubh,begin,size,offset)
 373 static inline unsigned _ubh_find_last_zero_bit_(
 374         struct ufs_sb_private_info * uspi, struct ufs_buffer_head * ubh,
 375         unsigned begin, unsigned start, unsigned end)
 376 {
 377         unsigned base, count, pos, size;
 378
 379         size = start - end;
 380         begin <<= 3;
 381         start += begin;
 382         base = start >> uspi->s_bpfshift;
 383         start &= uspi->s_bpfmask;
 384         for (;;) {
 385                 count = min (size + (uspi->s_bpf - start), uspi->s_bpf)
 386                         - (uspi->s_bpf - start);
 387                 size -= count;
 388                 pos = find_last_zero_bit (ubh->bh[base]->b_data,
 389                         start, start - count);
 390                 if (pos > start - count || !size)
 391                         break;
 392                 base--;
 393                 start = uspi->s_bpf;
 394         }
 395         return (base << uspi->s_bpfshift) + pos - begin;
 396 }
 397
 398 #define ubh_isblockclear(ubh,begin,block) (!_ubh_isblockset_(uspi,ubh,begin,block))
 399
 400 #define ubh_isblockset(ubh,begin,block) _ubh_isblockset_(uspi,ubh,begin,block)
 401 static inline int _ubh_isblockset_(struct ufs_sb_private_info * uspi,
 402         struct ufs_buffer_head * ubh, unsigned begin, unsigned block)
 403 {
 404         switch (uspi->s_fpb) {
 405         case 8:
 406                 return (*ubh_get_addr (ubh, begin + block) == 0xff);
 407         case 4:
 408                 return (*ubh_get_addr (ubh, begin + (block >> 1)) == (0x0f << ((block & 0x01) << 2)));
 409         case 2:
 410                 return (*ubh_get_addr (ubh, begin + (block >> 2)) == (0x03 << ((block & 0x03) << 1)));
 411         case 1:
 412                 return (*ubh_get_addr (ubh, begin + (block >> 3)) == (0x01 << (block & 0x07)));
 413         }
 414         return 0;
 415 }
 416
 417 #define ubh_clrblock(ubh,begin,block) _ubh_clrblock_(uspi,ubh,begin,block)
 418 static inline void _ubh_clrblock_(struct ufs_sb_private_info * uspi,
 419         struct ufs_buffer_head * ubh, unsigned begin, unsigned block)
 420 {
 421         switch (uspi->s_fpb) {
 422         case 8:
 423                 *ubh_get_addr (ubh, begin + block) = 0x00;
 424                 return;
 425         case 4:
 426                 *ubh_get_addr (ubh, begin + (block >> 1)) &= ~(0x0f << ((block & 0x01) << 2));
 427                 return;
 428         case 2:
 429                 *ubh_get_addr (ubh, begin + (block >> 2)) &= ~(0x03 << ((block & 0x03) << 1));
 430                 return;
 431         case 1:
 432                 *ubh_get_addr (ubh, begin + (block >> 3)) &= ~(0x01 << ((block & 0x07)));
 433                 return;
 434         }
 435 }
 436
 437 #define ubh_setblock(ubh,begin,block) _ubh_setblock_(uspi,ubh,begin,block)
 438 static inline void _ubh_setblock_(struct ufs_sb_private_info * uspi,
 439         struct ufs_buffer_head * ubh, unsigned begin, unsigned block)
 440 {
 441         switch (uspi->s_fpb) {
 442         case 8:
 443                 *ubh_get_addr(ubh, begin + block) = 0xff;
 444                 return;
 445         case 4:
 446                 *ubh_get_addr(ubh, begin + (block >> 1)) |= (0x0f << ((block & 0x01) << 2));
 447                 return;
 448         case 2:
 449                 *ubh_get_addr(ubh, begin + (block >> 2)) |= (0x03 << ((block & 0x03) << 1));
 450                 return;
 451         case 1:
 452                 *ubh_get_addr(ubh, begin + (block >> 3)) |= (0x01 << ((block & 0x07)));
 453                 return;
 454         }
 455 }
 456
 457 static inline void ufs_fragacct (struct super_block * sb, unsigned blockmap,
 458         unsigned * fraglist, int cnt)
 459 {
 460         struct ufs_sb_private_info * uspi;
 461         unsigned fragsize, pos;
 462         unsigned swab;
 463
 464         swab = sb->u.ufs_sb.s_swab;
 465         uspi = sb->u.ufs_sb.s_uspi;
 466
 467         fragsize = 0;
 468         for (pos = 0; pos < uspi->s_fpb; pos++) {
 469                 if (blockmap & (1 << pos)) {
 470                         fragsize++;
 471                 }
 472                 else if (fragsize > 0) {
 473                         ADD_SWAB32(fraglist[fragsize], cnt);
 474                         fragsize = 0;
 475                 }
 476         }
 477         if (fragsize > 0 && fragsize < uspi->s_fpb)
 478                 ADD_SWAB32(fraglist[fragsize], cnt);
 479 }
 480
 481 #define ubh_scanc(ubh,begin,size,table,mask) _ubh_scanc_(uspi,ubh,begin,size,table,mask)
 482 static inline unsigned _ubh_scanc_(struct ufs_sb_private_info * uspi, struct ufs_buffer_head * ubh,
 483         unsigned begin, unsigned size, unsigned char * table, unsigned char mask)
 484 {
 485         unsigned rest, offset;
 486         unsigned char * cp;
 487
 488
 489         offset = begin & ~uspi->s_fmask;
 490         begin >>= uspi->s_fshift;
 491         for (;;) {
 492                 if ((offset + size) < uspi->s_fsize)
 493                         rest = size;
 494                 else
 495                         rest = uspi->s_fsize - offset;
 496                 size -= rest;
 497                 cp = ubh->bh[begin]->b_data + offset;
 498                 while ((table[*cp++] & mask) == 0 && --rest);
 499                 if (rest || !size)
 500                         break;
 501                 begin++;
 502                 offset = 0;
 503         }
 504         return (size + rest);
 505 }