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/quotaops.h>
  30 #include <linux/buffer_head.h>
  31 #include <linux/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) __le ## x
  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         int result = offset & ~(BITS_PER_LONG-1);
  53         unsigned long 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         kernel_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,
 149         kernel_lb_addr bloc, uint32_t offset, uint32_t count)
 150 {
 151         struct udf_sb_info *sbi = UDF_SB(sb);
 152         struct buffer_head * bh = NULL;
 153         unsigned long block;
 154         unsigned long block_group;
 155         unsigned long bit;
 156         unsigned long i;
 157         int bitmap_nr;
 158         unsigned long overflow;
 159
 160         down(&sbi->s_alloc_sem);
 161         if (bloc.logicalBlockNum < 0 ||
 162                 (bloc.logicalBlockNum + count) > UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum))
 163         {
 164                 udf_debug("%d < %d || %d + %d > %d\n",
 165                         bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 166                         UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum));
 167                 goto error_return;
 168         }
 169
 170         block = bloc.logicalBlockNum + offset + (sizeof(struct spaceBitmapDesc) << 3);
 171
 172 do_more:
 173         overflow = 0;
 174         block_group = block >> (sb->s_blocksize_bits + 3);
 175         bit = block % (sb->s_blocksize << 3);
 176
 177         /*
 178          * Check to see if we are freeing blocks across a group boundary.
 179          */
 180         if (bit + count > (sb->s_blocksize << 3))
 181         {
 182                 overflow = bit + count - (sb->s_blocksize << 3);
 183                 count -= overflow;
 184         }
 185         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 186         if (bitmap_nr < 0)
 187                 goto error_return;
 188
 189         bh = bitmap->s_block_bitmap[bitmap_nr];
 190         for (i=0; i < count; i++)
 191         {
 192                 if (udf_set_bit(bit + i, bh->b_data))
 193                 {
 194                         udf_debug("bit %ld already set\n", bit + i);
 195                         udf_debug("byte=%2x\n", ((char *)bh->b_data)[(bit + i) >> 3]);
 196                 }
 197                 else
 198                 {
 199                         if (inode)
 200                                 DQUOT_FREE_BLOCK(inode, 1);
 201                         if (UDF_SB_LVIDBH(sb))
 202                         {
 203                                 UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)] =
 204                                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)])+1);
 205                         }
 206                 }
 207         }
 208         mark_buffer_dirty(bh);
 209         if (overflow)
 210         {
 211                 block += count;
 212                 count = overflow;
 213                 goto do_more;
 214         }
 215 error_return:
 216         sb->s_dirt = 1;
 217         if (UDF_SB_LVIDBH(sb))
 218                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 219         up(&sbi->s_alloc_sem);
 220         return;
 221 }
 222
 223 static int udf_bitmap_prealloc_blocks(struct super_block * sb,
 224         struct inode * inode,
 225         struct udf_bitmap *bitmap, uint16_t partition, uint32_t first_block,
 226         uint32_t block_count)
 227 {
 228         struct udf_sb_info *sbi = UDF_SB(sb);
 229         int alloc_count = 0;
 230         int bit, block, block_group, group_start;
 231         int nr_groups, bitmap_nr;
 232         struct buffer_head *bh;
 233
 234         down(&sbi->s_alloc_sem);
 235         if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
 236                 goto out;
 237
 238         if (first_block + block_count > UDF_SB_PARTLEN(sb, partition))
 239                 block_count = UDF_SB_PARTLEN(sb, partition) - first_block;
 240
 241 repeat:
 242         nr_groups = (UDF_SB_PARTLEN(sb, partition) +
 243                 (sizeof(struct spaceBitmapDesc) << 3) + (sb->s_blocksize * 8) - 1) / (sb->s_blocksize * 8);
 244         block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 245         block_group = block >> (sb->s_blocksize_bits + 3);
 246         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 247
 248         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 249         if (bitmap_nr < 0)
 250                 goto out;
 251         bh = bitmap->s_block_bitmap[bitmap_nr];
 252
 253         bit = block % (sb->s_blocksize << 3);
 254
 255         while (bit < (sb->s_blocksize << 3) && block_count > 0)
 256         {
 257                 if (!udf_test_bit(bit, bh->b_data))
 258                         goto out;
 259                 else if (DQUOT_PREALLOC_BLOCK(inode, 1))
 260                         goto out;
 261                 else if (!udf_clear_bit(bit, bh->b_data))
 262                 {
 263                         udf_debug("bit already cleared for block %d\n", bit);
 264                         DQUOT_FREE_BLOCK(inode, 1);
 265                         goto out;
 266                 }
 267                 block_count --;
 268                 alloc_count ++;
 269                 bit ++;
 270                 block ++;
 271         }
 272         mark_buffer_dirty(bh);
 273         if (block_count > 0)
 274                 goto repeat;
 275 out:
 276         if (UDF_SB_LVIDBH(sb))
 277         {
 278                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 279                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-alloc_count);
 280                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 281         }
 282         sb->s_dirt = 1;
 283         up(&sbi->s_alloc_sem);
 284         return alloc_count;
 285 }
 286
 287 static int udf_bitmap_new_block(struct super_block * sb,
 288         struct inode * inode,
 289         struct udf_bitmap *bitmap, uint16_t partition, uint32_t goal, int *err)
 290 {
 291         struct udf_sb_info *sbi = UDF_SB(sb);
 292         int newbit, bit=0, block, block_group, group_start;
 293         int end_goal, nr_groups, bitmap_nr, i;
 294         struct buffer_head *bh = NULL;
 295         char *ptr;
 296         int newblock = 0;
 297
 298         *err = -ENOSPC;
 299         down(&sbi->s_alloc_sem);
 300
 301 repeat:
 302         if (goal < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
 303                 goal = 0;
 304
 305         nr_groups = bitmap->s_nr_groups;
 306         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 307         block_group = block >> (sb->s_blocksize_bits + 3);
 308         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 309
 310         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 311         if (bitmap_nr < 0)
 312                 goto error_return;
 313         bh = bitmap->s_block_bitmap[bitmap_nr];
 314         ptr = memscan((char *)bh->b_data + group_start, 0xFF, sb->s_blocksize - group_start);
 315
 316         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize)
 317         {
 318                 bit = block % (sb->s_blocksize << 3);
 319
 320                 if (udf_test_bit(bit, bh->b_data))
 321                 {
 322                         goto got_block;
 323                 }
 324                 end_goal = (bit + 63) & ~63;
 325                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 326                 if (bit < end_goal)
 327                         goto got_block;
 328                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF, sb->s_blocksize - ((bit + 7) >> 3));
 329                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 330                 if (newbit < sb->s_blocksize << 3)
 331                 {
 332                         bit = newbit;
 333                         goto search_back;
 334                 }
 335                 newbit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, bit);
 336                 if (newbit < sb->s_blocksize << 3)
 337                 {
 338                         bit = newbit;
 339                         goto got_block;
 340                 }
 341         }
 342
 343         for (i=0; i<(nr_groups*2); i++)
 344         {
 345                 block_group ++;
 346                 if (block_group >= nr_groups)
 347                         block_group = 0;
 348                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 349
 350                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 351                 if (bitmap_nr < 0)
 352                         goto error_return;
 353                 bh = bitmap->s_block_bitmap[bitmap_nr];
 354                 if (i < nr_groups)
 355                 {
 356                         ptr = memscan((char *)bh->b_data + group_start, 0xFF, sb->s_blocksize - group_start);
 357                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize)
 358                         {
 359                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 360                                 break;
 361                         }
 362                 }
 363                 else
 364                 {
 365                         bit = udf_find_next_one_bit((char *)bh->b_data, sb->s_blocksize << 3, group_start << 3);
 366                         if (bit < sb->s_blocksize << 3)
 367                                 break;
 368                 }
 369         }
 370         if (i >= (nr_groups*2))
 371         {
 372                 up(&sbi->s_alloc_sem);
 373                 return newblock;
 374         }
 375         if (bit < sb->s_blocksize << 3)
 376                 goto search_back;
 377         else
 378                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, group_start << 3);
 379         if (bit >= sb->s_blocksize << 3)
 380         {
 381                 up(&sbi->s_alloc_sem);
 382                 return 0;
 383         }
 384
 385 search_back:
 386         for (i=0; i<7 && bit > (group_start << 3) && udf_test_bit(bit - 1, bh->b_data); i++, bit--);
 387
 388 got_block:
 389
 390         /*
 391          * Check quota for allocation of this block.
 392          */
 393         if (inode && DQUOT_ALLOC_BLOCK(inode, 1))
 394         {
 395                 up(&sbi->s_alloc_sem);
 396                 *err = -EDQUOT;
 397                 return 0;
 398         }
 399
 400         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 401                 (sizeof(struct spaceBitmapDesc) << 3);
 402
 403         if (!udf_clear_bit(bit, bh->b_data))
 404         {
 405                 udf_debug("bit already cleared for block %d\n", bit);
 406                 goto repeat;
 407         }
 408
 409         mark_buffer_dirty(bh);
 410
 411         if (UDF_SB_LVIDBH(sb))
 412         {
 413                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 414                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-1);
 415                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 416         }
 417         sb->s_dirt = 1;
 418         up(&sbi->s_alloc_sem);
 419         *err = 0;
 420         return newblock;
 421
 422 error_return:
 423         *err = -EIO;
 424         up(&sbi->s_alloc_sem);
 425         return 0;
 426 }
 427
 428 static void udf_table_free_blocks(struct super_block * sb,
 429         struct inode * inode,
 430         struct inode * table,
 431         kernel_lb_addr bloc, uint32_t offset, uint32_t count)
 432 {
 433         struct udf_sb_info *sbi = UDF_SB(sb);
 434         uint32_t start, end;
 435         uint32_t nextoffset, oextoffset, elen;
 436         kernel_lb_addr nbloc, obloc, eloc;
 437         struct buffer_head *obh, *nbh;
 438         int8_t etype;
 439         int i;
 440
 441         down(&sbi->s_alloc_sem);
 442         if (bloc.logicalBlockNum < 0 ||
 443                 (bloc.logicalBlockNum + count) > UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum))
 444         {
 445                 udf_debug("%d < %d || %d + %d > %d\n",
 446                         bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 447                         UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum));
 448                 goto error_return;
 449         }
 450
 451         /* We do this up front - There are some error conditions that could occure,
 452            but.. oh well */
 453         if (inode)
 454                 DQUOT_FREE_BLOCK(inode, count);
 455         if (UDF_SB_LVIDBH(sb))
 456         {
 457                 UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)] =
 458                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)])+count);
 459                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 460         }
 461
 462         start = bloc.logicalBlockNum + offset;
 463         end = bloc.logicalBlockNum + offset + count - 1;
 464
 465         oextoffset = nextoffset = sizeof(struct unallocSpaceEntry);
 466         elen = 0;
 467         obloc = nbloc = UDF_I_LOCATION(table);
 468
 469         obh = nbh = NULL;
 470
 471         while (count && (etype =
 472                 udf_next_aext(table, &nbloc, &nextoffset, &eloc, &elen, &nbh, 1)) != -1)
 473         {
 474                 if (((eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits)) ==
 475                         start))
 476                 {
 477                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits))
 478                         {
 479                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 480                                 start += ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 481                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 482                         }
 483                         else
 484                         {
 485                                 elen = (etype << 30) |
 486                                         (elen + (count << sb->s_blocksize_bits));
 487                                 start += count;
 488                                 count = 0;
 489                         }
 490                         udf_write_aext(table, obloc, &oextoffset, eloc, elen, obh, 1);
 491                 }
 492                 else if (eloc.logicalBlockNum == (end + 1))
 493                 {
 494                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits))
 495                         {
 496                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 497                                 end -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 498                                 eloc.logicalBlockNum -=
 499                                         ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 500                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 501                         }
 502                         else
 503                         {
 504                                 eloc.logicalBlockNum = start;
 505                                 elen = (etype << 30) |
 506                                         (elen + (count << sb->s_blocksize_bits));
 507                                 end -= count;
 508                                 count = 0;
 509                         }
 510                         udf_write_aext(table, obloc, &oextoffset, eloc, elen, obh, 1);
 511                 }
 512
 513                 if (nbh != obh)
 514                 {
 515                         i = -1;
 516                         obloc = nbloc;
 517                         udf_release_data(obh);
 518                         atomic_inc(&nbh->b_count);
 519                         obh = nbh;
 520                         oextoffset = 0;
 521                 }
 522                 else
 523                         oextoffset = nextoffset;
 524         }
 525
 526         if (count)
 527         {
 528                 /* NOTE: we CANNOT use udf_add_aext here, as it can try to allocate
 529                                  a new block, and since we hold the super block lock already
 530                                  very bad things would happen :)
 531
 532                                  We copy the behavior of udf_add_aext, but instead of
 533                                  trying to allocate a new block close to the existing one,
 534                                  we just steal a block from the extent we are trying to add.
 535
 536                                  It would be nice if the blocks were close together, but it
 537                                  isn't required.
 538                 */
 539
 540                 int adsize;
 541                 short_ad *sad = NULL;
 542                 long_ad *lad = NULL;
 543                 struct allocExtDesc *aed;
 544
 545                 eloc.logicalBlockNum = start;
 546                 elen = EXT_RECORDED_ALLOCATED |
 547                         (count << sb->s_blocksize_bits);
 548
 549                 if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 550                         adsize = sizeof(short_ad);
 551                 else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 552                         adsize = sizeof(long_ad);
 553                 else
 554                 {
 555                         udf_release_data(obh);
 556                         udf_release_data(nbh);
 557                         goto error_return;
 558                 }
 559
 560                 if (nextoffset + (2 * adsize) > sb->s_blocksize)
 561                 {
 562                         char *sptr, *dptr;
 563                         int loffset;
 564
 565                         udf_release_data(obh);
 566                         obh = nbh;
 567                         obloc = nbloc;
 568                         oextoffset = nextoffset;
 569
 570                         /* Steal a block from the extent being free'd */
 571                         nbloc.logicalBlockNum = eloc.logicalBlockNum;
 572                         eloc.logicalBlockNum ++;
 573                         elen -= sb->s_blocksize;
 574
 575                         if (!(nbh = udf_tread(sb,
 576                                 udf_get_lb_pblock(sb, nbloc, 0))))
 577                         {
 578                                 udf_release_data(obh);
 579                                 goto error_return;
 580                         }
 581                         aed = (struct allocExtDesc *)(nbh->b_data);
 582                         aed->previousAllocExtLocation = cpu_to_le32(obloc.logicalBlockNum);
 583                         if (nextoffset + adsize > sb->s_blocksize)
 584                         {
 585                                 loffset = nextoffset;
 586                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 587                                 if (obh)
 588                                         sptr = UDF_I_DATA(inode) + nextoffset -  udf_file_entry_alloc_offset(inode) + UDF_I_LENEATTR(inode) - adsize;
 589                                 else
 590                                         sptr = obh->b_data + nextoffset - adsize;
 591                                 dptr = nbh->b_data + sizeof(struct allocExtDesc);
 592                                 memcpy(dptr, sptr, adsize);
 593                                 nextoffset = sizeof(struct allocExtDesc) + adsize;
 594                         }
 595                         else
 596                         {
 597                                 loffset = nextoffset + adsize;
 598                                 aed->lengthAllocDescs = cpu_to_le32(0);
 599                                 sptr = (obh)->b_data + nextoffset;
 600                                 nextoffset = sizeof(struct allocExtDesc);
 601
 602                                 if (obh)
 603                                 {
 604                                         aed = (struct allocExtDesc *)(obh)->b_data;
 605                                         aed->lengthAllocDescs =
 606                                                 cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 607                                 }
 608                                 else
 609                                 {
 610                                         UDF_I_LENALLOC(table) += adsize;
 611                                         mark_inode_dirty(table);
 612                                 }
 613                         }
 614                         if (UDF_SB_UDFREV(sb) >= 0x0200)
 615                                 udf_new_tag(nbh->b_data, TAG_IDENT_AED, 3, 1,
 616                                         nbloc.logicalBlockNum, sizeof(tag));
 617                         else
 618                                 udf_new_tag(nbh->b_data, TAG_IDENT_AED, 2, 1,
 619                                         nbloc.logicalBlockNum, sizeof(tag));
 620                         switch (UDF_I_ALLOCTYPE(table))
 621                         {
 622                                 case ICBTAG_FLAG_AD_SHORT:
 623                                 {
 624                                         sad = (short_ad *)sptr;
 625                                         sad->extLength = cpu_to_le32(
 626                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 627                                                 sb->s_blocksize);
 628                                         sad->extPosition = cpu_to_le32(nbloc.logicalBlockNum);
 629                                         break;
 630                                 }
 631                                 case ICBTAG_FLAG_AD_LONG:
 632                                 {
 633                                         lad = (long_ad *)sptr;
 634                                         lad->extLength = cpu_to_le32(
 635                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 636                                                 sb->s_blocksize);
 637                                         lad->extLocation = cpu_to_lelb(nbloc);
 638                                         break;
 639                                 }
 640                         }
 641                         if (obh)
 642                         {
 643                                 udf_update_tag(obh->b_data, loffset);
 644                                 mark_buffer_dirty(obh);
 645                         }
 646                         else
 647                                 mark_inode_dirty(table);
 648                 }
 649
 650                 if (elen) /* It's possible that stealing the block emptied the extent */
 651                 {
 652                         udf_write_aext(table, nbloc, &nextoffset, eloc, elen, nbh, 1);
 653
 654                         if (!nbh)
 655                         {
 656                                 UDF_I_LENALLOC(table) += adsize;
 657                                 mark_inode_dirty(table);
 658                         }
 659                         else
 660                         {
 661                                 aed = (struct allocExtDesc *)nbh->b_data;
 662                                 aed->lengthAllocDescs =
 663                                         cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 664                                 udf_update_tag(nbh->b_data, nextoffset);
 665                                 mark_buffer_dirty(nbh);
 666                         }
 667                 }
 668         }
 669
 670         udf_release_data(nbh);
 671         udf_release_data(obh);
 672
 673 error_return:
 674         sb->s_dirt = 1;
 675         up(&sbi->s_alloc_sem);
 676         return;
 677 }
 678
 679 static int udf_table_prealloc_blocks(struct super_block * sb,
 680         struct inode * inode,
 681         struct inode *table, uint16_t partition, uint32_t first_block,
 682         uint32_t block_count)
 683 {
 684         struct udf_sb_info *sbi = UDF_SB(sb);
 685         int alloc_count = 0;
 686         uint32_t extoffset, elen, adsize;
 687         kernel_lb_addr bloc, eloc;
 688         struct buffer_head *bh;
 689         int8_t etype = -1;
 690
 691         if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
 692                 return 0;
 693
 694         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 695                 adsize = sizeof(short_ad);
 696         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 697                 adsize = sizeof(long_ad);
 698         else
 699                 return 0;
 700
 701         down(&sbi->s_alloc_sem);
 702         extoffset = sizeof(struct unallocSpaceEntry);
 703         bloc = UDF_I_LOCATION(table);
 704
 705         bh = NULL;
 706         eloc.logicalBlockNum = 0xFFFFFFFF;
 707
 708         while (first_block != eloc.logicalBlockNum && (etype =
 709                 udf_next_aext(table, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
 710         {
 711                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 712                         eloc.logicalBlockNum, elen, first_block);
 713                 ; /* empty loop body */
 714         }
 715
 716         if (first_block == eloc.logicalBlockNum)
 717         {
 718                 extoffset -= adsize;
 719
 720                 alloc_count = (elen >> sb->s_blocksize_bits);
 721                 if (inode && DQUOT_PREALLOC_BLOCK(inode, alloc_count > block_count ? block_count : alloc_count))
 722                         alloc_count = 0;
 723                 else if (alloc_count > block_count)
 724                 {
 725                         alloc_count = block_count;
 726                         eloc.logicalBlockNum += alloc_count;
 727                         elen -= (alloc_count << sb->s_blocksize_bits);
 728                         udf_write_aext(table, bloc, &extoffset, eloc, (etype << 30) | elen, bh, 1);
 729                 }
 730                 else
 731                         udf_delete_aext(table, bloc, extoffset, eloc, (etype << 30) | elen, bh);
 732         }
 733         else
 734                 alloc_count = 0;
 735
 736         udf_release_data(bh);
 737
 738         if (alloc_count && UDF_SB_LVIDBH(sb))
 739         {
 740                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 741                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-alloc_count);
 742                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 743                 sb->s_dirt = 1;
 744         }
 745         up(&sbi->s_alloc_sem);
 746         return alloc_count;
 747 }
 748
 749 static int udf_table_new_block(struct super_block * sb,
 750         struct inode * inode,
 751         struct inode *table, uint16_t partition, uint32_t goal, int *err)
 752 {
 753         struct udf_sb_info *sbi = UDF_SB(sb);
 754         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 755         uint32_t newblock = 0, adsize;
 756         uint32_t extoffset, goal_extoffset, elen, goal_elen = 0;
 757         kernel_lb_addr bloc, goal_bloc, eloc, goal_eloc;
 758         struct buffer_head *bh, *goal_bh;
 759         int8_t etype;
 760
 761         *err = -ENOSPC;
 762
 763         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 764                 adsize = sizeof(short_ad);
 765         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 766                 adsize = sizeof(long_ad);
 767         else
 768                 return newblock;
 769
 770         down(&sbi->s_alloc_sem);
 771         if (goal < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
 772                 goal = 0;
 773
 774         /* We search for the closest matching block to goal. If we find a exact hit,
 775            we stop. Otherwise we keep going till we run out of extents.
 776            We store the buffer_head, bloc, and extoffset of the current closest
 777            match and use that when we are done.
 778         */
 779
 780         extoffset = sizeof(struct unallocSpaceEntry);
 781         bloc = UDF_I_LOCATION(table);
 782
 783         goal_bh = bh = NULL;
 784
 785         while (spread && (etype =
 786                 udf_next_aext(table, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
 787         {
 788                 if (goal >= eloc.logicalBlockNum)
 789                 {
 790                         if (goal < eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits))
 791                                 nspread = 0;
 792                         else
 793                                 nspread = goal - eloc.logicalBlockNum -
 794                                         (elen >> sb->s_blocksize_bits);
 795                 }
 796                 else
 797                         nspread = eloc.logicalBlockNum - goal;
 798
 799                 if (nspread < spread)
 800                 {
 801                         spread = nspread;
 802                         if (goal_bh != bh)
 803                         {
 804                                 udf_release_data(goal_bh);
 805                                 goal_bh = bh;
 806                                 atomic_inc(&goal_bh->b_count);
 807                         }
 808                         goal_bloc = bloc;
 809                         goal_extoffset = extoffset - adsize;
 810                         goal_eloc = eloc;
 811                         goal_elen = (etype << 30) | elen;
 812                 }
 813         }
 814
 815         udf_release_data(bh);
 816
 817         if (spread == 0xFFFFFFFF)
 818         {
 819                 udf_release_data(goal_bh);
 820                 up(&sbi->s_alloc_sem);
 821                 return 0;
 822         }
 823
 824         /* Only allocate blocks from the beginning of the extent.
 825            That way, we only delete (empty) extents, never have to insert an
 826            extent because of splitting */
 827         /* This works, but very poorly.... */
 828
 829         newblock = goal_eloc.logicalBlockNum;
 830         goal_eloc.logicalBlockNum ++;
 831         goal_elen -= sb->s_blocksize;
 832
 833         if (inode && DQUOT_ALLOC_BLOCK(inode, 1))
 834         {
 835                 udf_release_data(goal_bh);
 836                 up(&sbi->s_alloc_sem);
 837                 *err = -EDQUOT;
 838                 return 0;
 839         }
 840
 841         if (goal_elen)
 842                 udf_write_aext(table, goal_bloc, &goal_extoffset, goal_eloc, goal_elen, goal_bh, 1);
 843         else
 844                 udf_delete_aext(table, goal_bloc, goal_extoffset, goal_eloc, goal_elen, goal_bh);
 845         udf_release_data(goal_bh);
 846
 847         if (UDF_SB_LVIDBH(sb))
 848         {
 849                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 850                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-1);
 851                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 852         }
 853
 854         sb->s_dirt = 1;
 855         up(&sbi->s_alloc_sem);
 856         *err = 0;
 857         return newblock;
 858 }
 859
 860 inline void udf_free_blocks(struct super_block * sb,
 861         struct inode * inode,
 862         kernel_lb_addr bloc, uint32_t offset, uint32_t count)
 863 {
 864         uint16_t partition = bloc.partitionReferenceNum;
 865
 866         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 867         {
 868                 return udf_bitmap_free_blocks(sb, inode,
 869                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 870                         bloc, offset, count);
 871         }
 872         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 873         {
 874                 return udf_table_free_blocks(sb, inode,
 875                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 876                         bloc, offset, count);
 877         }
 878         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 879         {
 880                 return udf_bitmap_free_blocks(sb, inode,
 881                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 882                         bloc, offset, count);
 883         }
 884         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 885         {
 886                 return udf_table_free_blocks(sb, inode,
 887                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 888                         bloc, offset, count);
 889         }
 890         else
 891                 return;
 892 }
 893
 894 inline int udf_prealloc_blocks(struct super_block * sb,
 895         struct inode * inode,
 896         uint16_t partition, uint32_t first_block, uint32_t block_count)
 897 {
 898         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 899         {
 900                 return udf_bitmap_prealloc_blocks(sb, inode,
 901                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 902                         partition, first_block, block_count);
 903         }
 904         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 905         {
 906                 return udf_table_prealloc_blocks(sb, inode,
 907                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 908                         partition, first_block, block_count);
 909         }
 910         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 911         {
 912                 return udf_bitmap_prealloc_blocks(sb, inode,
 913                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 914                         partition, first_block, block_count);
 915         }
 916         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 917         {
 918                 return udf_table_prealloc_blocks(sb, inode,
 919                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 920                         partition, first_block, block_count);
 921         }
 922         else
 923                 return 0;
 924 }
 925
 926 inline int udf_new_block(struct super_block * sb,
 927         struct inode * inode,
 928         uint16_t partition, uint32_t goal, int *err)
 929 {
 930         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 931         {
 932                 return udf_bitmap_new_block(sb, inode,
 933                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 934                         partition, goal, err);
 935         }
 936         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 937         {
 938                 return udf_table_new_block(sb, inode,
 939                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 940                         partition, goal, err);
 941         }
 942         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 943         {
 944                 return udf_bitmap_new_block(sb, inode,
 945                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 946                         partition, goal, err);
 947         }
 948         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 949         {
 950                 return udf_table_new_block(sb, inode,
 951                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 952                         partition, goal, err);
 953         }
 954         else
 955         {
 956                 *err = -EIO;
 957                 return 0;
 958         }
 959 }