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 (%d) > 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("%d < %d || %d + %d > %d\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 %ld already set\n", bit + i);
 178                                 udf_debug("byte=%2x\n",
 179                                           ((char *)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 int 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, block, block_group, group_start;
 250         int end_goal, nr_groups, bitmap_nr, i;
 251         struct buffer_head *bh = NULL;
 252         char *ptr;
 253         int newblock = 0;
 254
 255         *err = -ENOSPC;
 256         mutex_lock(&sbi->s_alloc_mutex);
 257
 258 repeat:
 259         if (goal >= sbi->s_partmaps[partition].s_partition_len)
 260                 goal = 0;
 261
 262         nr_groups = bitmap->s_nr_groups;
 263         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 264         block_group = block >> (sb->s_blocksize_bits + 3);
 265         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 266
 267         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 268         if (bitmap_nr < 0)
 269                 goto error_return;
 270         bh = bitmap->s_block_bitmap[bitmap_nr];
 271         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 272                       sb->s_blocksize - group_start);
 273
 274         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 275                 bit = block % (sb->s_blocksize << 3);
 276                 if (udf_test_bit(bit, bh->b_data))
 277                         goto got_block;
 278
 279                 end_goal = (bit + 63) & ~63;
 280                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 281                 if (bit < end_goal)
 282                         goto got_block;
 283
 284                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
 285                               sb->s_blocksize - ((bit + 7) >> 3));
 286                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 287                 if (newbit < sb->s_blocksize << 3) {
 288                         bit = newbit;
 289                         goto search_back;
 290                 }
 291
 292                 newbit = udf_find_next_one_bit(bh->b_data,
 293                                                sb->s_blocksize << 3, bit);
 294                 if (newbit < sb->s_blocksize << 3) {
 295                         bit = newbit;
 296                         goto got_block;
 297                 }
 298         }
 299
 300         for (i = 0; i < (nr_groups * 2); i++) {
 301                 block_group++;
 302                 if (block_group >= nr_groups)
 303                         block_group = 0;
 304                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 305
 306                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 307                 if (bitmap_nr < 0)
 308                         goto error_return;
 309                 bh = bitmap->s_block_bitmap[bitmap_nr];
 310                 if (i < nr_groups) {
 311                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 312                                       sb->s_blocksize - group_start);
 313                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 314                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 315                                 break;
 316                         }
 317                 } else {
 318                         bit = udf_find_next_one_bit(bh->b_data,
 319                                                     sb->s_blocksize << 3,
 320                                                     group_start << 3);
 321                         if (bit < sb->s_blocksize << 3)
 322                                 break;
 323                 }
 324         }
 325         if (i >= (nr_groups * 2)) {
 326                 mutex_unlock(&sbi->s_alloc_mutex);
 327                 return newblock;
 328         }
 329         if (bit < sb->s_blocksize << 3)
 330                 goto search_back;
 331         else
 332                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
 333                                             group_start << 3);
 334         if (bit >= sb->s_blocksize << 3) {
 335                 mutex_unlock(&sbi->s_alloc_mutex);
 336                 return 0;
 337         }
 338
 339 search_back:
 340         i = 0;
 341         while (i < 7 && bit > (group_start << 3) &&
 342                udf_test_bit(bit - 1, bh->b_data)) {
 343                 ++i;
 344                 --bit;
 345         }
 346
 347 got_block:
 348         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 349                 (sizeof(struct spaceBitmapDesc) << 3);
 350
 351         if (!udf_clear_bit(bit, bh->b_data)) {
 352                 udf_debug("bit already cleared for block %d\n", bit);
 353                 goto repeat;
 354         }
 355
 356         mark_buffer_dirty(bh);
 357
 358         udf_add_free_space(sb, partition, -1);
 359         mutex_unlock(&sbi->s_alloc_mutex);
 360         *err = 0;
 361         return newblock;
 362
 363 error_return:
 364         *err = -EIO;
 365         mutex_unlock(&sbi->s_alloc_mutex);
 366         return 0;
 367 }
 368
 369 static void udf_table_free_blocks(struct super_block *sb,
 370                                   struct inode *table,
 371                                   struct kernel_lb_addr *bloc,
 372                                   uint32_t offset,
 373                                   uint32_t count)
 374 {
 375         struct udf_sb_info *sbi = UDF_SB(sb);
 376         struct udf_part_map *partmap;
 377         uint32_t start, end;
 378         uint32_t elen;
 379         struct kernel_lb_addr eloc;
 380         struct extent_position oepos, epos;
 381         int8_t etype;
 382         struct udf_inode_info *iinfo;
 383
 384         mutex_lock(&sbi->s_alloc_mutex);
 385         partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 386         if (bloc->logicalBlockNum + count < count ||
 387             (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
 388                 udf_debug("%d < %d || %d + %d > %d\n",
 389                           bloc->logicalBlockNum, 0,
 390                           bloc->logicalBlockNum, count,
 391                           partmap->s_partition_len);
 392                 goto error_return;
 393         }
 394
 395         iinfo = UDF_I(table);
 396         udf_add_free_space(sb, sbi->s_partition, count);
 397
 398         start = bloc->logicalBlockNum + offset;
 399         end = bloc->logicalBlockNum + offset + count - 1;
 400
 401         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 402         elen = 0;
 403         epos.block = oepos.block = iinfo->i_location;
 404         epos.bh = oepos.bh = NULL;
 405
 406         while (count &&
 407                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 408                 if (((eloc.logicalBlockNum +
 409                         (elen >> sb->s_blocksize_bits)) == start)) {
 410                         if ((0x3FFFFFFF - elen) <
 411                                         (count << sb->s_blocksize_bits)) {
 412                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 413                                                         sb->s_blocksize_bits);
 414                                 count -= tmp;
 415                                 start += tmp;
 416                                 elen = (etype << 30) |
 417                                         (0x40000000 - sb->s_blocksize);
 418                         } else {
 419                                 elen = (etype << 30) |
 420                                         (elen +
 421                                         (count << sb->s_blocksize_bits));
 422                                 start += count;
 423                                 count = 0;
 424                         }
 425                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 426                 } else if (eloc.logicalBlockNum == (end + 1)) {
 427                         if ((0x3FFFFFFF - elen) <
 428                                         (count << sb->s_blocksize_bits)) {
 429                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 430                                                 sb->s_blocksize_bits);
 431                                 count -= tmp;
 432                                 end -= tmp;
 433                                 eloc.logicalBlockNum -= tmp;
 434                                 elen = (etype << 30) |
 435                                         (0x40000000 - sb->s_blocksize);
 436                         } else {
 437                                 eloc.logicalBlockNum = start;
 438                                 elen = (etype << 30) |
 439                                         (elen +
 440                                         (count << sb->s_blocksize_bits));
 441                                 end -= count;
 442                                 count = 0;
 443                         }
 444                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 445                 }
 446
 447                 if (epos.bh != oepos.bh) {
 448                         oepos.block = epos.block;
 449                         brelse(oepos.bh);
 450                         get_bh(epos.bh);
 451                         oepos.bh = epos.bh;
 452                         oepos.offset = 0;
 453                 } else {
 454                         oepos.offset = epos.offset;
 455                 }
 456         }
 457
 458         if (count) {
 459                 /*
 460                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
 461                  * allocate a new block, and since we hold the super block
 462                  * lock already very bad things would happen :)
 463                  *
 464                  * We copy the behavior of udf_add_aext, but instead of
 465                  * trying to allocate a new block close to the existing one,
 466                  * we just steal a block from the extent we are trying to add.
 467                  *
 468                  * It would be nice if the blocks were close together, but it
 469                  * isn't required.
 470                  */
 471
 472                 int adsize;
 473
 474                 eloc.logicalBlockNum = start;
 475                 elen = EXT_RECORDED_ALLOCATED |
 476                         (count << sb->s_blocksize_bits);
 477
 478                 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 479                         adsize = sizeof(struct short_ad);
 480                 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 481                         adsize = sizeof(struct long_ad);
 482                 else {
 483                         brelse(oepos.bh);
 484                         brelse(epos.bh);
 485                         goto error_return;
 486                 }
 487
 488                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 489                         /* Steal a block from the extent being free'd */
 490                         udf_setup_indirect_aext(table, eloc.logicalBlockNum,
 491                                                 &epos);
 492
 493                         eloc.logicalBlockNum++;
 494                         elen -= sb->s_blocksize;
 495                 }
 496
 497                 /* It's possible that stealing the block emptied the extent */
 498                 if (elen)
 499                         __udf_add_aext(table, &epos, &eloc, elen, 1);
 500         }
 501
 502         brelse(epos.bh);
 503         brelse(oepos.bh);
 504
 505 error_return:
 506         mutex_unlock(&sbi->s_alloc_mutex);
 507         return;
 508 }
 509
 510 static int udf_table_prealloc_blocks(struct super_block *sb,
 511                                      struct inode *table, uint16_t partition,
 512                                      uint32_t first_block, uint32_t block_count)
 513 {
 514         struct udf_sb_info *sbi = UDF_SB(sb);
 515         int alloc_count = 0;
 516         uint32_t elen, adsize;
 517         struct kernel_lb_addr eloc;
 518         struct extent_position epos;
 519         int8_t etype = -1;
 520         struct udf_inode_info *iinfo;
 521
 522         if (first_block >= sbi->s_partmaps[partition].s_partition_len)
 523                 return 0;
 524
 525         iinfo = UDF_I(table);
 526         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 527                 adsize = sizeof(struct short_ad);
 528         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 529                 adsize = sizeof(struct long_ad);
 530         else
 531                 return 0;
 532
 533         mutex_lock(&sbi->s_alloc_mutex);
 534         epos.offset = sizeof(struct unallocSpaceEntry);
 535         epos.block = iinfo->i_location;
 536         epos.bh = NULL;
 537         eloc.logicalBlockNum = 0xFFFFFFFF;
 538
 539         while (first_block != eloc.logicalBlockNum &&
 540                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 541                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 542                           eloc.logicalBlockNum, elen, first_block);
 543                 ; /* empty loop body */
 544         }
 545
 546         if (first_block == eloc.logicalBlockNum) {
 547                 epos.offset -= adsize;
 548
 549                 alloc_count = (elen >> sb->s_blocksize_bits);
 550                 if (alloc_count > block_count) {
 551                         alloc_count = block_count;
 552                         eloc.logicalBlockNum += alloc_count;
 553                         elen -= (alloc_count << sb->s_blocksize_bits);
 554                         udf_write_aext(table, &epos, &eloc,
 555                                         (etype << 30) | elen, 1);
 556                 } else
 557                         udf_delete_aext(table, epos);
 558         } else {
 559                 alloc_count = 0;
 560         }
 561
 562         brelse(epos.bh);
 563
 564         if (alloc_count)
 565                 udf_add_free_space(sb, partition, -alloc_count);
 566         mutex_unlock(&sbi->s_alloc_mutex);
 567         return alloc_count;
 568 }
 569
 570 static int udf_table_new_block(struct super_block *sb,
 571                                struct inode *table, uint16_t partition,
 572                                uint32_t goal, int *err)
 573 {
 574         struct udf_sb_info *sbi = UDF_SB(sb);
 575         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 576         uint32_t newblock = 0, adsize;
 577         uint32_t elen, goal_elen = 0;
 578         struct kernel_lb_addr eloc, goal_eloc;
 579         struct extent_position epos, goal_epos;
 580         int8_t etype;
 581         struct udf_inode_info *iinfo = UDF_I(table);
 582
 583         *err = -ENOSPC;
 584
 585         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 586                 adsize = sizeof(struct short_ad);
 587         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 588                 adsize = sizeof(struct long_ad);
 589         else
 590                 return newblock;
 591
 592         mutex_lock(&sbi->s_alloc_mutex);
 593         if (goal >= sbi->s_partmaps[partition].s_partition_len)
 594                 goal = 0;
 595
 596         /* We search for the closest matching block to goal. If we find
 597            a exact hit, we stop. Otherwise we keep going till we run out
 598            of extents. We store the buffer_head, bloc, and extoffset
 599            of the current closest match and use that when we are done.
 600          */
 601         epos.offset = sizeof(struct unallocSpaceEntry);
 602         epos.block = iinfo->i_location;
 603         epos.bh = goal_epos.bh = NULL;
 604
 605         while (spread &&
 606                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 607                 if (goal >= eloc.logicalBlockNum) {
 608                         if (goal < eloc.logicalBlockNum +
 609                                         (elen >> sb->s_blocksize_bits))
 610                                 nspread = 0;
 611                         else
 612                                 nspread = goal - eloc.logicalBlockNum -
 613                                         (elen >> sb->s_blocksize_bits);
 614                 } else {
 615                         nspread = eloc.logicalBlockNum - goal;
 616                 }
 617
 618                 if (nspread < spread) {
 619                         spread = nspread;
 620                         if (goal_epos.bh != epos.bh) {
 621                                 brelse(goal_epos.bh);
 622                                 goal_epos.bh = epos.bh;
 623                                 get_bh(goal_epos.bh);
 624                         }
 625                         goal_epos.block = epos.block;
 626                         goal_epos.offset = epos.offset - adsize;
 627                         goal_eloc = eloc;
 628                         goal_elen = (etype << 30) | elen;
 629                 }
 630         }
 631
 632         brelse(epos.bh);
 633
 634         if (spread == 0xFFFFFFFF) {
 635                 brelse(goal_epos.bh);
 636                 mutex_unlock(&sbi->s_alloc_mutex);
 637                 return 0;
 638         }
 639
 640         /* Only allocate blocks from the beginning of the extent.
 641            That way, we only delete (empty) extents, never have to insert an
 642            extent because of splitting */
 643         /* This works, but very poorly.... */
 644
 645         newblock = goal_eloc.logicalBlockNum;
 646         goal_eloc.logicalBlockNum++;
 647         goal_elen -= sb->s_blocksize;
 648
 649         if (goal_elen)
 650                 udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
 651         else
 652                 udf_delete_aext(table, goal_epos);
 653         brelse(goal_epos.bh);
 654
 655         udf_add_free_space(sb, partition, -1);
 656
 657         mutex_unlock(&sbi->s_alloc_mutex);
 658         *err = 0;
 659         return newblock;
 660 }
 661
 662 void udf_free_blocks(struct super_block *sb, struct inode *inode,
 663                      struct kernel_lb_addr *bloc, uint32_t offset,
 664                      uint32_t count)
 665 {
 666         uint16_t partition = bloc->partitionReferenceNum;
 667         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 668
 669         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 670                 udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,
 671                                        bloc, offset, count);
 672         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 673                 udf_table_free_blocks(sb, map->s_uspace.s_table,
 674                                       bloc, offset, count);
 675         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 676                 udf_bitmap_free_blocks(sb, map->s_fspace.s_bitmap,
 677                                        bloc, offset, count);
 678         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 679                 udf_table_free_blocks(sb, map->s_fspace.s_table,
 680                                       bloc, offset, count);
 681         }
 682
 683         if (inode) {
 684                 inode_sub_bytes(inode,
 685                                 ((sector_t)count) << sb->s_blocksize_bits);
 686         }
 687 }
 688
 689 inline int udf_prealloc_blocks(struct super_block *sb,
 690                                struct inode *inode,
 691                                uint16_t partition, uint32_t first_block,
 692                                uint32_t block_count)
 693 {
 694         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 695         int allocated;
 696
 697         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 698                 allocated = udf_bitmap_prealloc_blocks(sb,
 699                                                        map->s_uspace.s_bitmap,
 700                                                        partition, first_block,
 701                                                        block_count);
 702         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 703                 allocated = udf_table_prealloc_blocks(sb,
 704                                                       map->s_uspace.s_table,
 705                                                       partition, first_block,
 706                                                       block_count);
 707         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 708                 allocated = udf_bitmap_prealloc_blocks(sb,
 709                                                        map->s_fspace.s_bitmap,
 710                                                        partition, first_block,
 711                                                        block_count);
 712         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 713                 allocated = udf_table_prealloc_blocks(sb,
 714                                                       map->s_fspace.s_table,
 715                                                       partition, first_block,
 716                                                       block_count);
 717         else
 718                 return 0;
 719
 720         if (inode && allocated > 0)
 721                 inode_add_bytes(inode, allocated << sb->s_blocksize_bits);
 722         return allocated;
 723 }
 724
 725 inline int udf_new_block(struct super_block *sb,
 726                          struct inode *inode,
 727                          uint16_t partition, uint32_t goal, int *err)
 728 {
 729         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 730         int block;
 731
 732         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 733                 block = udf_bitmap_new_block(sb,
 734                                              map->s_uspace.s_bitmap,
 735                                              partition, goal, err);
 736         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 737                 block = udf_table_new_block(sb,
 738                                             map->s_uspace.s_table,
 739                                             partition, goal, err);
 740         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 741                 block = udf_bitmap_new_block(sb,
 742                                              map->s_fspace.s_bitmap,
 743                                              partition, goal, err);
 744         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 745                 block = udf_table_new_block(sb,
 746                                             map->s_fspace.s_table,
 747                                             partition, goal, err);
 748         else {
 749                 *err = -EIO;
 750                 return 0;
 751         }
 752         if (inode && block)
 753                 inode_add_bytes(inode, sb->s_blocksize);
 754         return block;
 755 }