fs/udf/balloc.c

   1 /*
   2  * balloc.c
   3  *
   4  * PURPOSE
   5  *      Block allocation handling routines for the OSTA-UDF(tm) filesystem.
   6  *
   7  * CONTACTS
   8  *      E-mail regarding any portion of the Linux UDF file system should be
   9  *      directed to the development team mailing list (run by majordomo):
  10  *              linux_udf@hpesjro.fc.hp.com
  11  *
  12  * COPYRIGHT
  13  *      This file is distributed under the terms of the GNU General Public
  14  *      License (GPL). Copies of the GPL can be obtained from:
  15  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
  16  *      Each contributing author retains all rights to their own work.
  17  *
  18  *  (C) 1999-2001 Ben Fennema
  19  *  (C) 1999 Stelias Computing Inc
  20  *
  21  * HISTORY
  22  *
  23  *  02/24/99 blf  Created.
  24  *
  25  */
  26
  27 #include "udfdecl.h"
  28
  29 #include <linux/locks.h>
  30 #include <linux/quotaops.h>
  31 #include <asm/bitops.h>
  32
  33 #include "udf_i.h"
  34 #include "udf_sb.h"
  35
  36 #define udf_clear_bit(nr,addr) ext2_clear_bit(nr,addr)
  37 #define udf_set_bit(nr,addr) ext2_set_bit(nr,addr)
  38 #define udf_test_bit(nr, addr) ext2_test_bit(nr, addr)
  39 #define udf_find_first_one_bit(addr, size) find_first_one_bit(addr, size)
  40 #define udf_find_next_one_bit(addr, size, offset) find_next_one_bit(addr, size, offset)
  41
  42 #define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x)
  43 #define leNUM_to_cpup(x,y) xleNUM_to_cpup(x,y)
  44 #define xleNUM_to_cpup(x,y) (le ## x ## _to_cpup(y))
  45 #define uintBPL_t uint(BITS_PER_LONG)
  46 #define uint(x) xuint(x)
  47 #define xuint(x) uint ## x ## _t
  48
  49 extern inline int find_next_one_bit (void * addr, int size, int offset)
  50 {
  51         uintBPL_t * p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG);
  52         uintBPL_t result = offset & ~(BITS_PER_LONG-1);
  53         uintBPL_t tmp;
  54
  55         if (offset >= size)
  56                 return size;
  57         size -= result;
  58         offset &= (BITS_PER_LONG-1);
  59         if (offset)
  60         {
  61                 tmp = leBPL_to_cpup(p++);
  62                 tmp &= ~0UL << offset;
  63                 if (size < BITS_PER_LONG)
  64                         goto found_first;
  65                 if (tmp)
  66                         goto found_middle;
  67                 size -= BITS_PER_LONG;
  68                 result += BITS_PER_LONG;
  69         }
  70         while (size & ~(BITS_PER_LONG-1))
  71         {
  72                 if ((tmp = leBPL_to_cpup(p++)))
  73                         goto found_middle;
  74                 result += BITS_PER_LONG;
  75                 size -= BITS_PER_LONG;
  76         }
  77         if (!size)
  78                 return result;
  79         tmp = leBPL_to_cpup(p);
  80 found_first:
  81         tmp &= ~0UL >> (BITS_PER_LONG-size);
  82 found_middle:
  83         return result + ffz(~tmp);
  84 }
  85
  86 #define find_first_one_bit(addr, size)\
  87         find_next_one_bit((addr), (size), 0)
  88
  89 static int read_block_bitmap(struct super_block * sb,
  90         struct udf_bitmap *bitmap, unsigned int block, unsigned long bitmap_nr)
  91 {
  92         struct buffer_head *bh = NULL;
  93         int retval = 0;
  94         lb_addr loc;
  95
  96         loc.logicalBlockNum = bitmap->s_extPosition;
  97         loc.partitionReferenceNum = UDF_SB_PARTITION(sb);
  98
  99         bh = udf_tread(sb, udf_get_lb_pblock(sb, loc, block));
 100         if (!bh)
 101         {
 102                 retval = -EIO;
 103         }
 104         bitmap->s_block_bitmap[bitmap_nr] = bh;
 105         return retval;
 106 }
 107
 108 static int __load_block_bitmap(struct super_block * sb,
 109         struct udf_bitmap *bitmap, unsigned int block_group)
 110 {
 111         int retval = 0;
 112         int nr_groups = bitmap->s_nr_groups;
 113
 114         if (block_group >= nr_groups)
 115         {
 116                 udf_debug("block_group (%d) > nr_groups (%d)\n", block_group, nr_groups);
 117         }
 118
 119         if (bitmap->s_block_bitmap[block_group])
 120                 return block_group;
 121         else
 122         {
 123                 retval = read_block_bitmap(sb, bitmap, block_group, block_group);
 124                 if (retval < 0)
 125                         return retval;
 126                 return block_group;
 127         }
 128 }
 129
 130 static inline int load_block_bitmap(struct super_block * sb,
 131         struct udf_bitmap *bitmap, unsigned int block_group)
 132 {
 133         int slot;
 134
 135         slot = __load_block_bitmap(sb, bitmap, block_group);
 136
 137         if (slot < 0)
 138                 return slot;
 139
 140         if (!bitmap->s_block_bitmap[slot])
 141                 return -EIO;
 142
 143         return slot;
 144 }
 145
 146 static void udf_bitmap_free_blocks(struct super_block * sb,
 147         struct inode * inode,
 148         struct udf_bitmap *bitmap, lb_addr bloc, uint32_t offset, uint32_t count)
 149 {
 150         struct buffer_head * bh = NULL;
 151         unsigned long block;
 152         unsigned long block_group;
 153         unsigned long bit;
 154         unsigned long i;
 155         int bitmap_nr;
 156         unsigned long overflow;
 157
 158         lock_super(sb);
 159         if (bloc.logicalBlockNum < 0 ||
 160                 (bloc.logicalBlockNum + count) > UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum))
 161         {
 162                 udf_debug("%d < %d || %d + %d > %d\n",
 163                         bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 164                         UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum));
 165                 goto error_return;
 166         }
 167
 168         block = bloc.logicalBlockNum + offset + (sizeof(struct spaceBitmapDesc) << 3);
 169
 170 do_more:
 171         overflow = 0;
 172         block_group = block >> (sb->s_blocksize_bits + 3);
 173         bit = block % (sb->s_blocksize << 3);
 174
 175         /*
 176          * Check to see if we are freeing blocks across a group boundary.
 177          */
 178         if (bit + count > (sb->s_blocksize << 3))
 179         {
 180                 overflow = bit + count - (sb->s_blocksize << 3);
 181                 count -= overflow;
 182         }
 183         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 184         if (bitmap_nr < 0)
 185                 goto error_return;
 186
 187         bh = bitmap->s_block_bitmap[bitmap_nr];
 188         for (i=0; i < count; i++)
 189         {
 190                 if (udf_set_bit(bit + i, bh->b_data))
 191                 {
 192                         udf_debug("bit %ld already set\n", bit + i);
 193                         udf_debug("byte=%2x\n", ((char *)bh->b_data)[(bit + i) >> 3]);
 194                 }
 195                 else
 196                 {
 197                         if (inode)
 198                                 DQUOT_FREE_BLOCK(inode, 1);
 199                         if (UDF_SB_LVIDBH(sb))
 200                         {
 201                                 UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)] =
 202                                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)])+1);
 203                         }
 204                 }
 205         }
 206         mark_buffer_dirty(bh);
 207         if (overflow)
 208         {
 209                 block += count;
 210                 count = overflow;
 211                 goto do_more;
 212         }
 213 error_return:
 214         sb->s_dirt = 1;
 215         if (UDF_SB_LVIDBH(sb))
 216                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 217         unlock_super(sb);
 218         return;
 219 }
 220
 221 static int udf_bitmap_prealloc_blocks(struct super_block * sb,
 222         struct inode * inode,
 223         struct udf_bitmap *bitmap, uint16_t partition, uint32_t first_block,
 224         uint32_t block_count)
 225 {
 226         int alloc_count = 0;
 227         int bit, block, block_group, group_start;
 228         int nr_groups, bitmap_nr;
 229         struct buffer_head *bh;
 230
 231         lock_super(sb);
 232
 233         if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
 234                 goto out;
 235
 236         if (first_block + block_count > UDF_SB_PARTLEN(sb, partition))
 237                 block_count = UDF_SB_PARTLEN(sb, partition) - first_block;
 238
 239 repeat:
 240         nr_groups = (UDF_SB_PARTLEN(sb, partition) +
 241                 (sizeof(struct spaceBitmapDesc) << 3) + (sb->s_blocksize * 8) - 1) / (sb->s_blocksize * 8);
 242         block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 243         block_group = block >> (sb->s_blocksize_bits + 3);
 244         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 245
 246         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 247         if (bitmap_nr < 0)
 248                 goto out;
 249         bh = bitmap->s_block_bitmap[bitmap_nr];
 250
 251         bit = block % (sb->s_blocksize << 3);
 252
 253         while (bit < (sb->s_blocksize << 3) && block_count > 0)
 254         {
 255                 if (!udf_test_bit(bit, bh->b_data))
 256                         goto out;
 257                 else if (DQUOT_PREALLOC_BLOCK(inode, 1))
 258                         goto out;
 259                 else if (!udf_clear_bit(bit, bh->b_data))
 260                 {
 261                         udf_debug("bit already cleared for block %d\n", bit);
 262                         DQUOT_FREE_BLOCK(inode, 1);
 263                         goto out;
 264                 }
 265                 block_count --;
 266                 alloc_count ++;
 267                 bit ++;
 268                 block ++;
 269         }
 270         mark_buffer_dirty(bh);
 271         if (block_count > 0)
 272                 goto repeat;
 273 out:
 274         if (UDF_SB_LVIDBH(sb))
 275         {
 276                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 277                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-alloc_count);
 278                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 279         }
 280         sb->s_dirt = 1;
 281         unlock_super(sb);
 282         return alloc_count;
 283 }
 284
 285 static int udf_bitmap_new_block(struct super_block * sb,
 286         struct inode * inode,
 287         struct udf_bitmap *bitmap, uint16_t partition, uint32_t goal, int *err)
 288 {
 289         int newbit, bit=0, block, block_group, group_start;
 290         int end_goal, nr_groups, bitmap_nr, i;
 291         struct buffer_head *bh = NULL;
 292         char *ptr;
 293         int newblock = 0;
 294
 295         *err = -ENOSPC;
 296         lock_super(sb);
 297
 298 repeat:
 299         if (goal < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
 300                 goal = 0;
 301
 302         nr_groups = bitmap->s_nr_groups;
 303         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 304         block_group = block >> (sb->s_blocksize_bits + 3);
 305         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 306
 307         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 308         if (bitmap_nr < 0)
 309                 goto error_return;
 310         bh = bitmap->s_block_bitmap[bitmap_nr];
 311         ptr = memscan((char *)bh->b_data + group_start, 0xFF, sb->s_blocksize - group_start);
 312
 313         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize)
 314         {
 315                 bit = block % (sb->s_blocksize << 3);
 316
 317                 if (udf_test_bit(bit, bh->b_data))
 318                 {
 319                         goto got_block;
 320                 }
 321                 end_goal = (bit + 63) & ~63;
 322                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 323                 if (bit < end_goal)
 324                         goto got_block;
 325                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF, sb->s_blocksize - ((bit + 7) >> 3));
 326                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 327                 if (newbit < sb->s_blocksize << 3)
 328                 {
 329                         bit = newbit;
 330                         goto search_back;
 331                 }
 332                 newbit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, bit);
 333                 if (newbit < sb->s_blocksize << 3)
 334                 {
 335                         bit = newbit;
 336                         goto got_block;
 337                 }
 338         }
 339
 340         for (i=0; i<(nr_groups*2); i++)
 341         {
 342                 block_group ++;
 343                 if (block_group >= nr_groups)
 344                         block_group = 0;
 345                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 346
 347                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 348                 if (bitmap_nr < 0)
 349                         goto error_return;
 350                 bh = bitmap->s_block_bitmap[bitmap_nr];
 351                 if (i < nr_groups)
 352                 {
 353                         ptr = memscan((char *)bh->b_data + group_start, 0xFF, sb->s_blocksize - group_start);
 354                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize)
 355                         {
 356                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 357                                 break;
 358                         }
 359                 }
 360                 else
 361                 {
 362                         bit = udf_find_next_one_bit((char *)bh->b_data, sb->s_blocksize << 3, group_start << 3);
 363                         if (bit < sb->s_blocksize << 3)
 364                                 break;
 365                 }
 366         }
 367         if (i >= (nr_groups*2))
 368         {
 369                 unlock_super(sb);
 370                 return newblock;
 371         }
 372         if (bit < sb->s_blocksize << 3)
 373                 goto search_back;
 374         else
 375                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, group_start << 3);
 376         if (bit >= sb->s_blocksize << 3)
 377         {
 378                 unlock_super(sb);
 379                 return 0;
 380         }
 381
 382 search_back:
 383         for (i=0; i<7 && bit > (group_start << 3) && udf_test_bit(bit - 1, bh->b_data); i++, bit--);
 384
 385 got_block:
 386
 387         /*
 388          * Check quota for allocation of this block.
 389          */
 390         if (inode && DQUOT_ALLOC_BLOCK(inode, 1))
 391         {
 392                 unlock_super(sb);
 393                 *err = -EDQUOT;
 394                 return 0;
 395         }
 396
 397         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 398                 (sizeof(struct spaceBitmapDesc) << 3);
 399
 400         if (!udf_clear_bit(bit, bh->b_data))
 401         {
 402                 udf_debug("bit already cleared for block %d\n", bit);
 403                 goto repeat;
 404         }
 405
 406         mark_buffer_dirty(bh);
 407
 408         if (UDF_SB_LVIDBH(sb))
 409         {
 410                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 411                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-1);
 412                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 413         }
 414         sb->s_dirt = 1;
 415         unlock_super(sb);
 416         *err = 0;
 417         return newblock;
 418
 419 error_return:
 420         *err = -EIO;
 421         unlock_super(sb);
 422         return 0;
 423 }
 424
 425 static void udf_table_free_blocks(struct super_block * sb,
 426         struct inode * inode,
 427         struct inode * table, lb_addr bloc, uint32_t offset, uint32_t count)
 428 {
 429         uint32_t start, end;
 430         uint32_t nextoffset, oextoffset, elen;
 431         lb_addr nbloc, obloc, eloc;
 432         struct buffer_head *obh, *nbh;
 433         int8_t etype;
 434         int i;
 435
 436         lock_super(sb);
 437         if (bloc.logicalBlockNum < 0 ||
 438                 (bloc.logicalBlockNum + count) > UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum))
 439         {
 440                 udf_debug("%d < %d || %d + %d > %d\n",
 441                         bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 442                         UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum));
 443                 goto error_return;
 444         }
 445
 446         /* We do this up front - There are some error conditions that could occure,
 447            but.. oh well */
 448         if (inode)
 449                 DQUOT_FREE_BLOCK(inode, count);
 450         if (UDF_SB_LVIDBH(sb))
 451         {
 452                 UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)] =
 453                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)])+count);
 454                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 455         }
 456
 457         start = bloc.logicalBlockNum + offset;
 458         end = bloc.logicalBlockNum + offset + count - 1;
 459
 460         oextoffset = nextoffset = sizeof(struct unallocSpaceEntry);
 461         elen = 0;
 462         obloc = nbloc = UDF_I_LOCATION(table);
 463
 464         obh = nbh = udf_tread(sb, udf_get_lb_pblock(sb, nbloc, 0));
 465         atomic_inc(&nbh->b_count);
 466
 467         while (count && (etype =
 468                 udf_next_aext(table, &nbloc, &nextoffset, &eloc, &elen, &nbh, 1)) != -1)
 469         {
 470                 if (((eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits)) ==
 471                         start))
 472                 {
 473                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits))
 474                         {
 475                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 476                                 start += ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 477                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 478                         }
 479                         else
 480                         {
 481                                 elen = (etype << 30) |
 482                                         (elen + (count << sb->s_blocksize_bits));
 483                                 start += count;
 484                                 count = 0;
 485                         }
 486                         udf_write_aext(table, obloc, &oextoffset, eloc, elen, obh, 1);
 487                 }
 488                 else if (eloc.logicalBlockNum == (end + 1))
 489                 {
 490                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits))
 491                         {
 492                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 493                                 end -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 494                                 eloc.logicalBlockNum -=
 495                                         ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 496                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 497                         }
 498                         else
 499                         {
 500                                 eloc.logicalBlockNum = start;
 501                                 elen = (etype << 30) |
 502                                         (elen + (count << sb->s_blocksize_bits));
 503                                 end -= count;
 504                                 count = 0;
 505                         }
 506                         udf_write_aext(table, obloc, &oextoffset, eloc, elen, obh, 1);
 507                 }
 508
 509                 if (memcmp(&nbloc, &obloc, sizeof(lb_addr)))
 510                 {
 511                         i = -1;
 512                         obloc = nbloc;
 513                         udf_release_data(obh);
 514                         atomic_inc(&nbh->b_count);
 515                         obh = nbh;
 516                         oextoffset = 0;
 517                 }
 518                 else
 519                         oextoffset = nextoffset;
 520         }
 521
 522         if (count)
 523         {
 524                 /* NOTE: we CANNOT use udf_add_aext here, as it can try to allocate
 525                                  a new block, and since we hold the super block lock already
 526                                  very bad things would happen :)
 527
 528                                  We copy the behavior of udf_add_aext, but instead of
 529                                  trying to allocate a new block close to the existing one,
 530                                  we just steal a block from the extent we are trying to add.
 531
 532                                  It would be nice if the blocks were close together, but it
 533                                  isn't required.
 534                 */
 535
 536                 int adsize;
 537                 short_ad *sad = NULL;
 538                 long_ad *lad = NULL;
 539                 struct allocExtDesc *aed;
 540
 541                 eloc.logicalBlockNum = start;
 542                 elen = EXT_RECORDED_ALLOCATED |
 543                         (count << sb->s_blocksize_bits);
 544
 545                 if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 546                         adsize = sizeof(short_ad);
 547                 else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 548                         adsize = sizeof(long_ad);
 549                 else
 550                 {
 551                         udf_release_data(obh);
 552                         udf_release_data(nbh);
 553                         goto error_return;
 554                 }
 555
 556                 if (nextoffset + (2 * adsize) > sb->s_blocksize)
 557                 {
 558                         char *sptr, *dptr;
 559                         int loffset;
 560
 561                         udf_release_data(obh);
 562                         obh = nbh;
 563                         obloc = nbloc;
 564                         oextoffset = nextoffset;
 565
 566                         /* Steal a block from the extent being free'd */
 567                         nbloc.logicalBlockNum = eloc.logicalBlockNum;
 568                         eloc.logicalBlockNum ++;
 569                         elen -= sb->s_blocksize;
 570
 571                         if (!(nbh = udf_tread(sb,
 572                                 udf_get_lb_pblock(sb, nbloc, 0))))
 573                         {
 574                                 udf_release_data(obh);
 575                                 goto error_return;
 576                         }
 577                         aed = (struct allocExtDesc *)(nbh->b_data);
 578                         aed->previousAllocExtLocation = cpu_to_le32(obloc.logicalBlockNum);
 579                         if (nextoffset + adsize > sb->s_blocksize)
 580                         {
 581                                 loffset = nextoffset;
 582                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 583                                 sptr = (obh)->b_data + nextoffset - adsize;
 584                                 dptr = nbh->b_data + sizeof(struct allocExtDesc);
 585                                 memcpy(dptr, sptr, adsize);
 586                                 nextoffset = sizeof(struct allocExtDesc) + adsize;
 587                         }
 588                         else
 589                         {
 590                                 loffset = nextoffset + adsize;
 591                                 aed->lengthAllocDescs = cpu_to_le32(0);
 592                                 sptr = (obh)->b_data + nextoffset;
 593                                 nextoffset = sizeof(struct allocExtDesc);
 594
 595                                 if (memcmp(&UDF_I_LOCATION(table), &obloc, sizeof(lb_addr)))
 596                                 {
 597                                         aed = (struct allocExtDesc *)(obh)->b_data;
 598                                         aed->lengthAllocDescs =
 599                                                 cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 600                                 }
 601                                 else
 602                                 {
 603                                         UDF_I_LENALLOC(table) += adsize;
 604                                         mark_inode_dirty(table);
 605                                 }
 606                         }
 607                         if (UDF_SB_UDFREV(sb) >= 0x0200)
 608                                 udf_new_tag(nbh->b_data, TAG_IDENT_AED, 3, 1,
 609                                         nbloc.logicalBlockNum, sizeof(tag));
 610                         else
 611                                 udf_new_tag(nbh->b_data, TAG_IDENT_AED, 2, 1,
 612                                         nbloc.logicalBlockNum, sizeof(tag));
 613                         switch (UDF_I_ALLOCTYPE(table))
 614                         {
 615                                 case ICBTAG_FLAG_AD_SHORT:
 616                                 {
 617                                         sad = (short_ad *)sptr;
 618                                         sad->extLength = cpu_to_le32(
 619                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 620                                                 sb->s_blocksize);
 621                                         sad->extPosition = cpu_to_le32(nbloc.logicalBlockNum);
 622                                         break;
 623                                 }
 624                                 case ICBTAG_FLAG_AD_LONG:
 625                                 {
 626                                         lad = (long_ad *)sptr;
 627                                         lad->extLength = cpu_to_le32(
 628                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 629                                                 sb->s_blocksize);
 630                                         lad->extLocation = cpu_to_lelb(nbloc);
 631                                         break;
 632                                 }
 633                         }
 634                         udf_update_tag(obh->b_data, loffset);
 635                         mark_buffer_dirty(obh);
 636                 }
 637
 638                 if (elen) /* It's possible that stealing the block emptied the extent */
 639                 {
 640                         udf_write_aext(table, nbloc, &nextoffset, eloc, elen, nbh, 1);
 641
 642                         if (!memcmp(&UDF_I_LOCATION(table), &nbloc, sizeof(lb_addr)))
 643                         {
 644                                 UDF_I_LENALLOC(table) += adsize;
 645                                 mark_inode_dirty(table);
 646                         }
 647                         else
 648                         {
 649                                 aed = (struct allocExtDesc *)nbh->b_data;
 650                                 aed->lengthAllocDescs =
 651                                         cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 652                                 udf_update_tag(nbh->b_data, nextoffset);
 653                                 mark_buffer_dirty(nbh);
 654                         }
 655                 }
 656         }
 657
 658         udf_release_data(nbh);
 659         udf_release_data(obh);
 660
 661 error_return:
 662         sb->s_dirt = 1;
 663         unlock_super(sb);
 664         return;
 665 }
 666
 667 static int udf_table_prealloc_blocks(struct super_block * sb,
 668         struct inode * inode,
 669         struct inode *table, uint16_t partition, uint32_t first_block,
 670         uint32_t block_count)
 671 {
 672         int alloc_count = 0;
 673         uint32_t extoffset, elen, adsize;
 674         lb_addr bloc, eloc;
 675         struct buffer_head *bh;
 676         int8_t etype = -1;
 677
 678         if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
 679                 return 0;
 680
 681         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 682                 adsize = sizeof(short_ad);
 683         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 684                 adsize = sizeof(long_ad);
 685         else
 686                 return 0;
 687
 688         lock_super(sb);
 689
 690         extoffset = sizeof(struct unallocSpaceEntry);
 691         bloc = UDF_I_LOCATION(table);
 692
 693         bh = udf_tread(sb, udf_get_lb_pblock(sb, bloc, 0));
 694         eloc.logicalBlockNum = 0xFFFFFFFF;
 695
 696         while (first_block != eloc.logicalBlockNum && (etype =
 697                 udf_next_aext(table, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
 698         {
 699                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 700                         eloc.logicalBlockNum, elen, first_block);
 701                 ; /* empty loop body */
 702         }
 703
 704         if (first_block == eloc.logicalBlockNum)
 705         {
 706                 extoffset -= adsize;
 707
 708                 alloc_count = (elen >> sb->s_blocksize_bits);
 709                 if (inode && DQUOT_PREALLOC_BLOCK(inode, alloc_count > block_count ? block_count : alloc_count))
 710                         alloc_count = 0;
 711                 else if (alloc_count > block_count)
 712                 {
 713                         alloc_count = block_count;
 714                         eloc.logicalBlockNum += alloc_count;
 715                         elen -= (alloc_count << sb->s_blocksize_bits);
 716                         udf_write_aext(table, bloc, &extoffset, eloc, (etype << 30) | elen, bh, 1);
 717                 }
 718                 else
 719                         udf_delete_aext(table, bloc, extoffset, eloc, (etype << 30) | elen, bh);
 720         }
 721         else
 722                 alloc_count = 0;
 723
 724         udf_release_data(bh);
 725
 726         if (alloc_count && UDF_SB_LVIDBH(sb))
 727         {
 728                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 729                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-alloc_count);
 730                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 731                 sb->s_dirt = 1;
 732         }
 733         unlock_super(sb);
 734         return alloc_count;
 735 }
 736
 737 static int udf_table_new_block(struct super_block * sb,
 738         struct inode * inode,
 739         struct inode *table, uint16_t partition, uint32_t goal, int *err)
 740 {
 741         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 742         uint32_t newblock = 0, adsize;
 743         uint32_t extoffset, goal_extoffset, elen, goal_elen = 0;
 744         lb_addr bloc, goal_bloc, eloc, goal_eloc;
 745         struct buffer_head *bh, *goal_bh;
 746         int8_t etype;
 747
 748         *err = -ENOSPC;
 749
 750         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 751                 adsize = sizeof(short_ad);
 752         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 753                 adsize = sizeof(long_ad);
 754         else
 755                 return newblock;
 756
 757         lock_super(sb);
 758
 759         if (goal < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
 760                 goal = 0;
 761
 762         /* We search for the closest matching block to goal. If we find a exact hit,
 763            we stop. Otherwise we keep going till we run out of extents.
 764            We store the buffer_head, bloc, and extoffset of the current closest
 765            match and use that when we are done.
 766         */
 767
 768         extoffset = sizeof(struct unallocSpaceEntry);
 769         bloc = UDF_I_LOCATION(table);
 770
 771         goal_bh = bh = udf_tread(sb, udf_get_lb_pblock(sb, bloc, 0));
 772         atomic_inc(&goal_bh->b_count);
 773
 774         while (spread && (etype =
 775                 udf_next_aext(table, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
 776         {
 777                 if (goal >= eloc.logicalBlockNum)
 778                 {
 779                         if (goal < eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits))
 780                                 nspread = 0;
 781                         else
 782                                 nspread = goal - eloc.logicalBlockNum -
 783                                         (elen >> sb->s_blocksize_bits);
 784                 }
 785                 else
 786                         nspread = eloc.logicalBlockNum - goal;
 787
 788                 if (nspread < spread)
 789                 {
 790                         spread = nspread;
 791                         if (goal_bh != bh)
 792                         {
 793                                 udf_release_data(goal_bh);
 794                                 goal_bh = bh;
 795                                 atomic_inc(&goal_bh->b_count);
 796                         }
 797                         goal_bloc = bloc;
 798                         goal_extoffset = extoffset - adsize;
 799                         goal_eloc = eloc;
 800                         goal_elen = (etype << 30) | elen;
 801                 }
 802         }
 803
 804         udf_release_data(bh);
 805
 806         if (spread == 0xFFFFFFFF)
 807         {
 808                 udf_release_data(goal_bh);
 809                 unlock_super(sb);
 810                 return 0;
 811         }
 812
 813         /* Only allocate blocks from the beginning of the extent.
 814            That way, we only delete (empty) extents, never have to insert an
 815            extent because of splitting */
 816         /* This works, but very poorly.... */
 817
 818         newblock = goal_eloc.logicalBlockNum;
 819         goal_eloc.logicalBlockNum ++;
 820         goal_elen -= sb->s_blocksize;
 821
 822         if (inode && DQUOT_ALLOC_BLOCK(inode, 1))
 823         {
 824                 udf_release_data(goal_bh);
 825                 unlock_super(sb);
 826                 *err = -EDQUOT;
 827                 return 0;
 828         }
 829
 830         if (goal_elen)
 831                 udf_write_aext(table, goal_bloc, &goal_extoffset, goal_eloc, goal_elen, goal_bh, 1);
 832         else
 833                 udf_delete_aext(table, goal_bloc, goal_extoffset, goal_eloc, goal_elen, goal_bh);
 834         udf_release_data(goal_bh);
 835
 836         if (UDF_SB_LVIDBH(sb))
 837         {
 838                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 839                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-1);
 840                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 841         }
 842
 843         sb->s_dirt = 1;
 844         unlock_super(sb);
 845         *err = 0;
 846         return newblock;
 847 }
 848
 849 inline void udf_free_blocks(struct super_block * sb,
 850         struct inode * inode,
 851         lb_addr bloc, uint32_t offset, uint32_t count)
 852 {
 853         uint16_t partition = bloc.partitionReferenceNum;
 854
 855         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 856         {
 857                 return udf_bitmap_free_blocks(sb, inode,
 858                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 859                         bloc, offset, count);
 860         }
 861         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 862         {
 863                 return udf_table_free_blocks(sb, inode,
 864                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 865                         bloc, offset, count);
 866         }
 867         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 868         {
 869                 return udf_bitmap_free_blocks(sb, inode,
 870                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 871                         bloc, offset, count);
 872         }
 873         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 874         {
 875                 return udf_table_free_blocks(sb, inode,
 876                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 877                         bloc, offset, count);
 878         }
 879         else
 880                 return;
 881 }
 882
 883 inline int udf_prealloc_blocks(struct super_block * sb,
 884         struct inode * inode,
 885         uint16_t partition, uint32_t first_block, uint32_t block_count)
 886 {
 887         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 888         {
 889                 return udf_bitmap_prealloc_blocks(sb, inode,
 890                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 891                         partition, first_block, block_count);
 892         }
 893         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 894         {
 895                 return udf_table_prealloc_blocks(sb, inode,
 896                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 897                         partition, first_block, block_count);
 898         }
 899         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 900         {
 901                 return udf_bitmap_prealloc_blocks(sb, inode,
 902                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 903                         partition, first_block, block_count);
 904         }
 905         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 906         {
 907                 return udf_table_prealloc_blocks(sb, inode,
 908                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 909                         partition, first_block, block_count);
 910         }
 911         else
 912                 return 0;
 913 }
 914
 915 inline int udf_new_block(struct super_block * sb,
 916         struct inode * inode,
 917         uint16_t partition, uint32_t goal, int *err)
 918 {
 919         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 920         {
 921                 return udf_bitmap_new_block(sb, inode,
 922                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 923                         partition, goal, err);
 924         }
 925         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 926         {
 927                 return udf_table_new_block(sb, inode,
 928                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 929                         partition, goal, err);
 930         }
 931         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 932         {
 933                 return udf_bitmap_new_block(sb, inode,
 934                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 935                         partition, goal, err);
 936         }
 937         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 938         {
 939                 return udf_table_new_block(sb, inode,
 940                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 941                         partition, goal, err);
 942         }
 943         else
 944         {
 945                 *err = -EIO;
 946                 return 0;
 947         }
 948 }