fs/udf/balloc.c

   1 /*
   2  * balloc.c
   3  *
   4  * PURPOSE
   5  *      Block allocation handling routines for the OSTA-UDF(tm) filesystem.
   6  *
   7  * COPYRIGHT
   8  *      This file is distributed under the terms of the GNU General Public
   9  *      License (GPL). Copies of the GPL can be obtained from:
  10  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
  11  *      Each contributing author retains all rights to their own work.
  12  *
  13  *  (C) 1999-2001 Ben Fennema
  14  *  (C) 1999 Stelias Computing Inc
  15  *
  16  * HISTORY
  17  *
  18  *  02/24/99 blf  Created.
  19  *
  20  */
  21
  22 #include "udfdecl.h"
  23
  24 #include <linux/bitops.h>
  25
  26 #include "udf_i.h"
  27 #include "udf_sb.h"
  28
  29 #define udf_clear_bit   __test_and_clear_bit_le
  30 #define udf_set_bit     __test_and_set_bit_le
  31 #define udf_test_bit    test_bit_le
  32 #define udf_find_next_one_bit   find_next_bit_le
  33
  34 static int read_block_bitmap(struct super_block *sb,
  35                              struct udf_bitmap *bitmap, unsigned int block,
  36                              unsigned long bitmap_nr)
  37 {
  38         struct buffer_head *bh = NULL;
  39         int i;
  40         int max_bits, off, count;
  41         struct kernel_lb_addr loc;
  42
  43         loc.logicalBlockNum = bitmap->s_extPosition;
  44         loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
  45
  46         bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block));
  47         bitmap->s_block_bitmap[bitmap_nr] = bh;
  48         if (!bh)
  49                 return -EIO;
  50
  51         /* Check consistency of Space Bitmap buffer. */
  52         max_bits = sb->s_blocksize * 8;
  53         if (!bitmap_nr) {
  54                 off = sizeof(struct spaceBitmapDesc) << 3;
  55                 count = min(max_bits - off, bitmap->s_nr_groups);
  56         } else {
  57                 /*
  58                  * Rough check if bitmap number is too big to have any bitmap
  59                  * blocks reserved.
  60                  */
  61                 if (bitmap_nr >
  62                     (bitmap->s_nr_groups >> (sb->s_blocksize_bits + 3)) + 2)
  63                         return 0;
  64                 off = 0;
  65                 count = bitmap->s_nr_groups - bitmap_nr * max_bits +
  66                                 (sizeof(struct spaceBitmapDesc) << 3);
  67                 count = min(count, max_bits);
  68         }
  69
  70         for (i = 0; i < count; i++)
  71                 if (udf_test_bit(i + off, bh->b_data))
  72                         return -EFSCORRUPTED;
  73         return 0;
  74 }
  75
  76 static int __load_block_bitmap(struct super_block *sb,
  77                                struct udf_bitmap *bitmap,
  78                                unsigned int block_group)
  79 {
  80         int retval = 0;
  81         int nr_groups = bitmap->s_nr_groups;
  82
  83         if (block_group >= nr_groups) {
  84                 udf_debug("block_group (%u) > nr_groups (%d)\n",
  85                           block_group, nr_groups);
  86         }
  87
  88         if (bitmap->s_block_bitmap[block_group])
  89                 return block_group;
  90
  91         retval = read_block_bitmap(sb, bitmap, block_group, block_group);
  92         if (retval < 0)
  93                 return retval;
  94
  95         return block_group;
  96 }
  97
  98 static inline int load_block_bitmap(struct super_block *sb,
  99                                     struct udf_bitmap *bitmap,
 100                                     unsigned int block_group)
 101 {
 102         int slot;
 103
 104         slot = __load_block_bitmap(sb, bitmap, block_group);
 105
 106         if (slot < 0)
 107                 return slot;
 108
 109         if (!bitmap->s_block_bitmap[slot])
 110                 return -EIO;
 111
 112         return slot;
 113 }
 114
 115 static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
 116 {
 117         struct udf_sb_info *sbi = UDF_SB(sb);
 118         struct logicalVolIntegrityDesc *lvid;
 119
 120         if (!sbi->s_lvid_bh)
 121                 return;
 122
 123         lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 124         le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
 125         udf_updated_lvid(sb);
 126 }
 127
 128 static void udf_bitmap_free_blocks(struct super_block *sb,
 129                                    struct udf_bitmap *bitmap,
 130                                    struct kernel_lb_addr *bloc,
 131                                    uint32_t offset,
 132                                    uint32_t count)
 133 {
 134         struct udf_sb_info *sbi = UDF_SB(sb);
 135         struct buffer_head *bh = NULL;
 136         struct udf_part_map *partmap;
 137         unsigned long block;
 138         unsigned long block_group;
 139         unsigned long bit;
 140         unsigned long i;
 141         int bitmap_nr;
 142         unsigned long overflow;
 143
 144         mutex_lock(&sbi->s_alloc_mutex);
 145         partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 146         if (bloc->logicalBlockNum + count < count ||
 147             (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
 148                 udf_debug("%u < %d || %u + %u > %u\n",
 149                           bloc->logicalBlockNum, 0,
 150                           bloc->logicalBlockNum, count,
 151                           partmap->s_partition_len);
 152                 goto error_return;
 153         }
 154
 155         block = bloc->logicalBlockNum + offset +
 156                 (sizeof(struct spaceBitmapDesc) << 3);
 157
 158         do {
 159                 overflow = 0;
 160                 block_group = block >> (sb->s_blocksize_bits + 3);
 161                 bit = block % (sb->s_blocksize << 3);
 162
 163                 /*
 164                 * Check to see if we are freeing blocks across a group boundary.
 165                 */
 166                 if (bit + count > (sb->s_blocksize << 3)) {
 167                         overflow = bit + count - (sb->s_blocksize << 3);
 168                         count -= overflow;
 169                 }
 170                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 171                 if (bitmap_nr < 0)
 172                         goto error_return;
 173
 174                 bh = bitmap->s_block_bitmap[bitmap_nr];
 175                 for (i = 0; i < count; i++) {
 176                         if (udf_set_bit(bit + i, bh->b_data)) {
 177                                 udf_debug("bit %lu already set\n", bit + i);
 178                                 udf_debug("byte=%2x\n",
 179                                           ((__u8 *)bh->b_data)[(bit + i) >> 3]);
 180                         }
 181                 }
 182                 udf_add_free_space(sb, sbi->s_partition, count);
 183                 mark_buffer_dirty(bh);
 184                 if (overflow) {
 185                         block += count;
 186                         count = overflow;
 187                 }
 188         } while (overflow);
 189
 190 error_return:
 191         mutex_unlock(&sbi->s_alloc_mutex);
 192 }
 193
 194 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 195                                       struct udf_bitmap *bitmap,
 196                                       uint16_t partition, uint32_t first_block,
 197                                       uint32_t block_count)
 198 {
 199         struct udf_sb_info *sbi = UDF_SB(sb);
 200         int alloc_count = 0;
 201         int bit, block, block_group, group_start;
 202         int nr_groups, bitmap_nr;
 203         struct buffer_head *bh;
 204         __u32 part_len;
 205
 206         mutex_lock(&sbi->s_alloc_mutex);
 207         part_len = sbi->s_partmaps[partition].s_partition_len;
 208         if (first_block >= part_len)
 209                 goto out;
 210
 211         if (first_block + block_count > part_len)
 212                 block_count = part_len - first_block;
 213
 214         do {
 215                 nr_groups = udf_compute_nr_groups(sb, partition);
 216                 block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 217                 block_group = block >> (sb->s_blocksize_bits + 3);
 218                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 219
 220                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 221                 if (bitmap_nr < 0)
 222                         goto out;
 223                 bh = bitmap->s_block_bitmap[bitmap_nr];
 224
 225                 bit = block % (sb->s_blocksize << 3);
 226
 227                 while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 228                         if (!udf_clear_bit(bit, bh->b_data))
 229                                 goto out;
 230                         block_count--;
 231                         alloc_count++;
 232                         bit++;
 233                         block++;
 234                 }
 235                 mark_buffer_dirty(bh);
 236         } while (block_count > 0);
 237
 238 out:
 239         udf_add_free_space(sb, partition, -alloc_count);
 240         mutex_unlock(&sbi->s_alloc_mutex);
 241         return alloc_count;
 242 }
 243
 244 static udf_pblk_t udf_bitmap_new_block(struct super_block *sb,
 245                                 struct udf_bitmap *bitmap, uint16_t partition,
 246                                 uint32_t goal, int *err)
 247 {
 248         struct udf_sb_info *sbi = UDF_SB(sb);
 249         int newbit, bit = 0;
 250         udf_pblk_t block;
 251         int block_group, group_start;
 252         int end_goal, nr_groups, bitmap_nr, i;
 253         struct buffer_head *bh = NULL;
 254         char *ptr;
 255         udf_pblk_t newblock = 0;
 256
 257         *err = -ENOSPC;
 258         mutex_lock(&sbi->s_alloc_mutex);
 259
 260 repeat:
 261         if (goal >= sbi->s_partmaps[partition].s_partition_len)
 262                 goal = 0;
 263
 264         nr_groups = bitmap->s_nr_groups;
 265         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 266         block_group = block >> (sb->s_blocksize_bits + 3);
 267         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 268
 269         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 270         if (bitmap_nr < 0)
 271                 goto error_return;
 272         bh = bitmap->s_block_bitmap[bitmap_nr];
 273         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 274                       sb->s_blocksize - group_start);
 275
 276         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 277                 bit = block % (sb->s_blocksize << 3);
 278                 if (udf_test_bit(bit, bh->b_data))
 279                         goto got_block;
 280
 281                 end_goal = (bit + 63) & ~63;
 282                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 283                 if (bit < end_goal)
 284                         goto got_block;
 285
 286                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
 287                               sb->s_blocksize - ((bit + 7) >> 3));
 288                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 289                 if (newbit < sb->s_blocksize << 3) {
 290                         bit = newbit;
 291                         goto search_back;
 292                 }
 293
 294                 newbit = udf_find_next_one_bit(bh->b_data,
 295                                                sb->s_blocksize << 3, bit);
 296                 if (newbit < sb->s_blocksize << 3) {
 297                         bit = newbit;
 298                         goto got_block;
 299                 }
 300         }
 301
 302         for (i = 0; i < (nr_groups * 2); i++) {
 303                 block_group++;
 304                 if (block_group >= nr_groups)
 305                         block_group = 0;
 306                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 307
 308                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 309                 if (bitmap_nr < 0)
 310                         goto error_return;
 311                 bh = bitmap->s_block_bitmap[bitmap_nr];
 312                 if (i < nr_groups) {
 313                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 314                                       sb->s_blocksize - group_start);
 315                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 316                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 317                                 break;
 318                         }
 319                 } else {
 320                         bit = udf_find_next_one_bit(bh->b_data,
 321                                                     sb->s_blocksize << 3,
 322                                                     group_start << 3);
 323                         if (bit < sb->s_blocksize << 3)
 324                                 break;
 325                 }
 326         }
 327         if (i >= (nr_groups * 2)) {
 328                 mutex_unlock(&sbi->s_alloc_mutex);
 329                 return newblock;
 330         }
 331         if (bit < sb->s_blocksize << 3)
 332                 goto search_back;
 333         else
 334                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
 335                                             group_start << 3);
 336         if (bit >= sb->s_blocksize << 3) {
 337                 mutex_unlock(&sbi->s_alloc_mutex);
 338                 return 0;
 339         }
 340
 341 search_back:
 342         i = 0;
 343         while (i < 7 && bit > (group_start << 3) &&
 344                udf_test_bit(bit - 1, bh->b_data)) {
 345                 ++i;
 346                 --bit;
 347         }
 348
 349 got_block:
 350         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 351                 (sizeof(struct spaceBitmapDesc) << 3);
 352
 353         if (!udf_clear_bit(bit, bh->b_data)) {
 354                 udf_debug("bit already cleared for block %d\n", bit);
 355                 goto repeat;
 356         }
 357
 358         mark_buffer_dirty(bh);
 359
 360         udf_add_free_space(sb, partition, -1);
 361         mutex_unlock(&sbi->s_alloc_mutex);
 362         *err = 0;
 363         return newblock;
 364
 365 error_return:
 366         *err = -EIO;
 367         mutex_unlock(&sbi->s_alloc_mutex);
 368         return 0;
 369 }
 370
 371 static void udf_table_free_blocks(struct super_block *sb,
 372                                   struct inode *table,
 373                                   struct kernel_lb_addr *bloc,
 374                                   uint32_t offset,
 375                                   uint32_t count)
 376 {
 377         struct udf_sb_info *sbi = UDF_SB(sb);
 378         struct udf_part_map *partmap;
 379         uint32_t start, end;
 380         uint32_t elen;
 381         struct kernel_lb_addr eloc;
 382         struct extent_position oepos, epos;
 383         int8_t etype;
 384         struct udf_inode_info *iinfo;
 385
 386         mutex_lock(&sbi->s_alloc_mutex);
 387         partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 388         if (bloc->logicalBlockNum + count < count ||
 389             (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
 390                 udf_debug("%u < %d || %u + %u > %u\n",
 391                           bloc->logicalBlockNum, 0,
 392                           bloc->logicalBlockNum, count,
 393                           partmap->s_partition_len);
 394                 goto error_return;
 395         }
 396
 397         iinfo = UDF_I(table);
 398         udf_add_free_space(sb, sbi->s_partition, count);
 399
 400         start = bloc->logicalBlockNum + offset;
 401         end = bloc->logicalBlockNum + offset + count - 1;
 402
 403         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 404         elen = 0;
 405         epos.block = oepos.block = iinfo->i_location;
 406         epos.bh = oepos.bh = NULL;
 407
 408         while (count &&
 409                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 410                 if (((eloc.logicalBlockNum +
 411                         (elen >> sb->s_blocksize_bits)) == start)) {
 412                         if ((0x3FFFFFFF - elen) <
 413                                         (count << sb->s_blocksize_bits)) {
 414                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 415                                                         sb->s_blocksize_bits);
 416                                 count -= tmp;
 417                                 start += tmp;
 418                                 elen = (etype << 30) |
 419                                         (0x40000000 - sb->s_blocksize);
 420                         } else {
 421                                 elen = (etype << 30) |
 422                                         (elen +
 423                                         (count << sb->s_blocksize_bits));
 424                                 start += count;
 425                                 count = 0;
 426                         }
 427                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 428                 } else if (eloc.logicalBlockNum == (end + 1)) {
 429                         if ((0x3FFFFFFF - elen) <
 430                                         (count << sb->s_blocksize_bits)) {
 431                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 432                                                 sb->s_blocksize_bits);
 433                                 count -= tmp;
 434                                 end -= tmp;
 435                                 eloc.logicalBlockNum -= tmp;
 436                                 elen = (etype << 30) |
 437                                         (0x40000000 - sb->s_blocksize);
 438                         } else {
 439                                 eloc.logicalBlockNum = start;
 440                                 elen = (etype << 30) |
 441                                         (elen +
 442                                         (count << sb->s_blocksize_bits));
 443                                 end -= count;
 444                                 count = 0;
 445                         }
 446                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 447                 }
 448
 449                 if (epos.bh != oepos.bh) {
 450                         oepos.block = epos.block;
 451                         brelse(oepos.bh);
 452                         get_bh(epos.bh);
 453                         oepos.bh = epos.bh;
 454                         oepos.offset = 0;
 455                 } else {
 456                         oepos.offset = epos.offset;
 457                 }
 458         }
 459
 460         if (count) {
 461                 /*
 462                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
 463                  * allocate a new block, and since we hold the super block
 464                  * lock already very bad things would happen :)
 465                  *
 466                  * We copy the behavior of udf_add_aext, but instead of
 467                  * trying to allocate a new block close to the existing one,
 468                  * we just steal a block from the extent we are trying to add.
 469                  *
 470                  * It would be nice if the blocks were close together, but it
 471                  * isn't required.
 472                  */
 473
 474                 int adsize;
 475
 476                 eloc.logicalBlockNum = start;
 477                 elen = EXT_RECORDED_ALLOCATED |
 478                         (count << sb->s_blocksize_bits);
 479
 480                 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 481                         adsize = sizeof(struct short_ad);
 482                 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 483                         adsize = sizeof(struct long_ad);
 484                 else {
 485                         brelse(oepos.bh);
 486                         brelse(epos.bh);
 487                         goto error_return;
 488                 }
 489
 490                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 491                         /* Steal a block from the extent being free'd */
 492                         udf_setup_indirect_aext(table, eloc.logicalBlockNum,
 493                                                 &epos);
 494
 495                         eloc.logicalBlockNum++;
 496                         elen -= sb->s_blocksize;
 497                 }
 498
 499                 /* It's possible that stealing the block emptied the extent */
 500                 if (elen)
 501                         __udf_add_aext(table, &epos, &eloc, elen, 1);
 502         }
 503
 504         brelse(epos.bh);
 505         brelse(oepos.bh);
 506
 507 error_return:
 508         mutex_unlock(&sbi->s_alloc_mutex);
 509         return;
 510 }
 511
 512 static int udf_table_prealloc_blocks(struct super_block *sb,
 513                                      struct inode *table, uint16_t partition,
 514                                      uint32_t first_block, uint32_t block_count)
 515 {
 516         struct udf_sb_info *sbi = UDF_SB(sb);
 517         int alloc_count = 0;
 518         uint32_t elen, adsize;
 519         struct kernel_lb_addr eloc;
 520         struct extent_position epos;
 521         int8_t etype = -1;
 522         struct udf_inode_info *iinfo;
 523
 524         if (first_block >= sbi->s_partmaps[partition].s_partition_len)
 525                 return 0;
 526
 527         iinfo = UDF_I(table);
 528         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 529                 adsize = sizeof(struct short_ad);
 530         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 531                 adsize = sizeof(struct long_ad);
 532         else
 533                 return 0;
 534
 535         mutex_lock(&sbi->s_alloc_mutex);
 536         epos.offset = sizeof(struct unallocSpaceEntry);
 537         epos.block = iinfo->i_location;
 538         epos.bh = NULL;
 539         eloc.logicalBlockNum = 0xFFFFFFFF;
 540
 541         while (first_block != eloc.logicalBlockNum &&
 542                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 543                 udf_debug("eloc=%u, elen=%u, first_block=%u\n",
 544                           eloc.logicalBlockNum, elen, first_block);
 545                 ; /* empty loop body */
 546         }
 547
 548         if (first_block == eloc.logicalBlockNum) {
 549                 epos.offset -= adsize;
 550
 551                 alloc_count = (elen >> sb->s_blocksize_bits);
 552                 if (alloc_count > block_count) {
 553                         alloc_count = block_count;
 554                         eloc.logicalBlockNum += alloc_count;
 555                         elen -= (alloc_count << sb->s_blocksize_bits);
 556                         udf_write_aext(table, &epos, &eloc,
 557                                         (etype << 30) | elen, 1);
 558                 } else
 559                         udf_delete_aext(table, epos);
 560         } else {
 561                 alloc_count = 0;
 562         }
 563
 564         brelse(epos.bh);
 565
 566         if (alloc_count)
 567                 udf_add_free_space(sb, partition, -alloc_count);
 568         mutex_unlock(&sbi->s_alloc_mutex);
 569         return alloc_count;
 570 }
 571
 572 static udf_pblk_t udf_table_new_block(struct super_block *sb,
 573                                struct inode *table, uint16_t partition,
 574                                uint32_t goal, int *err)
 575 {
 576         struct udf_sb_info *sbi = UDF_SB(sb);
 577         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 578         udf_pblk_t newblock = 0;
 579         uint32_t adsize;
 580         uint32_t elen, goal_elen = 0;
 581         struct kernel_lb_addr eloc, goal_eloc;
 582         struct extent_position epos, goal_epos;
 583         int8_t etype;
 584         struct udf_inode_info *iinfo = UDF_I(table);
 585
 586         *err = -ENOSPC;
 587
 588         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 589                 adsize = sizeof(struct short_ad);
 590         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 591                 adsize = sizeof(struct long_ad);
 592         else
 593                 return newblock;
 594
 595         mutex_lock(&sbi->s_alloc_mutex);
 596         if (goal >= sbi->s_partmaps[partition].s_partition_len)
 597                 goal = 0;
 598
 599         /* We search for the closest matching block to goal. If we find
 600            a exact hit, we stop. Otherwise we keep going till we run out
 601            of extents. We store the buffer_head, bloc, and extoffset
 602            of the current closest match and use that when we are done.
 603          */
 604         epos.offset = sizeof(struct unallocSpaceEntry);
 605         epos.block = iinfo->i_location;
 606         epos.bh = goal_epos.bh = NULL;
 607
 608         while (spread &&
 609                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 610                 if (goal >= eloc.logicalBlockNum) {
 611                         if (goal < eloc.logicalBlockNum +
 612                                         (elen >> sb->s_blocksize_bits))
 613                                 nspread = 0;
 614                         else
 615                                 nspread = goal - eloc.logicalBlockNum -
 616                                         (elen >> sb->s_blocksize_bits);
 617                 } else {
 618                         nspread = eloc.logicalBlockNum - goal;
 619                 }
 620
 621                 if (nspread < spread) {
 622                         spread = nspread;
 623                         if (goal_epos.bh != epos.bh) {
 624                                 brelse(goal_epos.bh);
 625                                 goal_epos.bh = epos.bh;
 626                                 get_bh(goal_epos.bh);
 627                         }
 628                         goal_epos.block = epos.block;
 629                         goal_epos.offset = epos.offset - adsize;
 630                         goal_eloc = eloc;
 631                         goal_elen = (etype << 30) | elen;
 632                 }
 633         }
 634
 635         brelse(epos.bh);
 636
 637         if (spread == 0xFFFFFFFF) {
 638                 brelse(goal_epos.bh);
 639                 mutex_unlock(&sbi->s_alloc_mutex);
 640                 return 0;
 641         }
 642
 643         /* Only allocate blocks from the beginning of the extent.
 644            That way, we only delete (empty) extents, never have to insert an
 645            extent because of splitting */
 646         /* This works, but very poorly.... */
 647
 648         newblock = goal_eloc.logicalBlockNum;
 649         goal_eloc.logicalBlockNum++;
 650         goal_elen -= sb->s_blocksize;
 651
 652         if (goal_elen)
 653                 udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
 654         else
 655                 udf_delete_aext(table, goal_epos);
 656         brelse(goal_epos.bh);
 657
 658         udf_add_free_space(sb, partition, -1);
 659
 660         mutex_unlock(&sbi->s_alloc_mutex);
 661         *err = 0;
 662         return newblock;
 663 }
 664
 665 void udf_free_blocks(struct super_block *sb, struct inode *inode,
 666                      struct kernel_lb_addr *bloc, uint32_t offset,
 667                      uint32_t count)
 668 {
 669         uint16_t partition = bloc->partitionReferenceNum;
 670         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 671
 672         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 673                 udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,
 674                                        bloc, offset, count);
 675         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 676                 udf_table_free_blocks(sb, map->s_uspace.s_table,
 677                                       bloc, offset, count);
 678         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 679                 udf_bitmap_free_blocks(sb, map->s_fspace.s_bitmap,
 680                                        bloc, offset, count);
 681         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 682                 udf_table_free_blocks(sb, map->s_fspace.s_table,
 683                                       bloc, offset, count);
 684         }
 685
 686         if (inode) {
 687                 inode_sub_bytes(inode,
 688                                 ((sector_t)count) << sb->s_blocksize_bits);
 689         }
 690 }
 691
 692 inline int udf_prealloc_blocks(struct super_block *sb,
 693                                struct inode *inode,
 694                                uint16_t partition, uint32_t first_block,
 695                                uint32_t block_count)
 696 {
 697         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 698         int allocated;
 699
 700         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 701                 allocated = udf_bitmap_prealloc_blocks(sb,
 702                                                        map->s_uspace.s_bitmap,
 703                                                        partition, first_block,
 704                                                        block_count);
 705         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 706                 allocated = udf_table_prealloc_blocks(sb,
 707                                                       map->s_uspace.s_table,
 708                                                       partition, first_block,
 709                                                       block_count);
 710         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 711                 allocated = udf_bitmap_prealloc_blocks(sb,
 712                                                        map->s_fspace.s_bitmap,
 713                                                        partition, first_block,
 714                                                        block_count);
 715         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 716                 allocated = udf_table_prealloc_blocks(sb,
 717                                                       map->s_fspace.s_table,
 718                                                       partition, first_block,
 719                                                       block_count);
 720         else
 721                 return 0;
 722
 723         if (inode && allocated > 0)
 724                 inode_add_bytes(inode, allocated << sb->s_blocksize_bits);
 725         return allocated;
 726 }
 727
 728 inline udf_pblk_t udf_new_block(struct super_block *sb,
 729                          struct inode *inode,
 730                          uint16_t partition, uint32_t goal, int *err)
 731 {
 732         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 733         udf_pblk_t block;
 734
 735         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 736                 block = udf_bitmap_new_block(sb,
 737                                              map->s_uspace.s_bitmap,
 738                                              partition, goal, err);
 739         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 740                 block = udf_table_new_block(sb,
 741                                             map->s_uspace.s_table,
 742                                             partition, goal, err);
 743         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 744                 block = udf_bitmap_new_block(sb,
 745                                              map->s_fspace.s_bitmap,
 746                                              partition, goal, err);
 747         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 748                 block = udf_table_new_block(sb,
 749                                             map->s_fspace.s_table,
 750                                             partition, goal, err);
 751         else {
 752                 *err = -EIO;
 753                 return 0;
 754         }
 755         if (inode && block)
 756                 inode_add_bytes(inode, sb->s_blocksize);
 757         return block;
 758 }