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/buffer_head.h>
  25 #include <linux/bitops.h>
  26
  27 #include "udf_i.h"
  28 #include "udf_sb.h"
  29
  30 #define udf_clear_bit   __test_and_clear_bit_le
  31 #define udf_set_bit     __test_and_set_bit_le
  32 #define udf_test_bit    test_bit_le
  33 #define udf_find_next_one_bit   find_next_bit_le
  34
  35 static int read_block_bitmap(struct super_block *sb,
  36                              struct udf_bitmap *bitmap, unsigned int block,
  37                              unsigned long bitmap_nr)
  38 {
  39         struct buffer_head *bh = NULL;
  40         int retval = 0;
  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         if (!bh)
  48                 retval = -EIO;
  49
  50         bitmap->s_block_bitmap[bitmap_nr] = bh;
  51         return retval;
  52 }
  53
  54 static int __load_block_bitmap(struct super_block *sb,
  55                                struct udf_bitmap *bitmap,
  56                                unsigned int block_group)
  57 {
  58         int retval = 0;
  59         int nr_groups = bitmap->s_nr_groups;
  60
  61         if (block_group >= nr_groups) {
  62                 udf_debug("block_group (%d) > nr_groups (%d)\n",
  63                           block_group, nr_groups);
  64         }
  65
  66         if (bitmap->s_block_bitmap[block_group]) {
  67                 return block_group;
  68         } else {
  69                 retval = read_block_bitmap(sb, bitmap, block_group,
  70                                            block_group);
  71                 if (retval < 0)
  72                         return retval;
  73                 return block_group;
  74         }
  75 }
  76
  77 static inline int load_block_bitmap(struct super_block *sb,
  78                                     struct udf_bitmap *bitmap,
  79                                     unsigned int block_group)
  80 {
  81         int slot;
  82
  83         slot = __load_block_bitmap(sb, bitmap, block_group);
  84
  85         if (slot < 0)
  86                 return slot;
  87
  88         if (!bitmap->s_block_bitmap[slot])
  89                 return -EIO;
  90
  91         return slot;
  92 }
  93
  94 static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
  95 {
  96         struct udf_sb_info *sbi = UDF_SB(sb);
  97         struct logicalVolIntegrityDesc *lvid;
  98
  99         if (!sbi->s_lvid_bh)
 100                 return;
 101
 102         lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 103         le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
 104         udf_updated_lvid(sb);
 105 }
 106
 107 static void udf_bitmap_free_blocks(struct super_block *sb,
 108                                    struct udf_bitmap *bitmap,
 109                                    struct kernel_lb_addr *bloc,
 110                                    uint32_t offset,
 111                                    uint32_t count)
 112 {
 113         struct udf_sb_info *sbi = UDF_SB(sb);
 114         struct buffer_head *bh = NULL;
 115         struct udf_part_map *partmap;
 116         unsigned long block;
 117         unsigned long block_group;
 118         unsigned long bit;
 119         unsigned long i;
 120         int bitmap_nr;
 121         unsigned long overflow;
 122
 123         mutex_lock(&sbi->s_alloc_mutex);
 124         partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 125         if (bloc->logicalBlockNum + count < count ||
 126             (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
 127                 udf_debug("%d < %d || %d + %d > %d\n",
 128                           bloc->logicalBlockNum, 0,
 129                           bloc->logicalBlockNum, count,
 130                           partmap->s_partition_len);
 131                 goto error_return;
 132         }
 133
 134         block = bloc->logicalBlockNum + offset +
 135                 (sizeof(struct spaceBitmapDesc) << 3);
 136
 137         do {
 138                 overflow = 0;
 139                 block_group = block >> (sb->s_blocksize_bits + 3);
 140                 bit = block % (sb->s_blocksize << 3);
 141
 142                 /*
 143                 * Check to see if we are freeing blocks across a group boundary.
 144                 */
 145                 if (bit + count > (sb->s_blocksize << 3)) {
 146                         overflow = bit + count - (sb->s_blocksize << 3);
 147                         count -= overflow;
 148                 }
 149                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 150                 if (bitmap_nr < 0)
 151                         goto error_return;
 152
 153                 bh = bitmap->s_block_bitmap[bitmap_nr];
 154                 for (i = 0; i < count; i++) {
 155                         if (udf_set_bit(bit + i, bh->b_data)) {
 156                                 udf_debug("bit %ld already set\n", bit + i);
 157                                 udf_debug("byte=%2x\n",
 158                                           ((char *)bh->b_data)[(bit + i) >> 3]);
 159                         }
 160                 }
 161                 udf_add_free_space(sb, sbi->s_partition, count);
 162                 mark_buffer_dirty(bh);
 163                 if (overflow) {
 164                         block += count;
 165                         count = overflow;
 166                 }
 167         } while (overflow);
 168
 169 error_return:
 170         mutex_unlock(&sbi->s_alloc_mutex);
 171 }
 172
 173 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 174                                       struct udf_bitmap *bitmap,
 175                                       uint16_t partition, uint32_t first_block,
 176                                       uint32_t block_count)
 177 {
 178         struct udf_sb_info *sbi = UDF_SB(sb);
 179         int alloc_count = 0;
 180         int bit, block, block_group, group_start;
 181         int nr_groups, bitmap_nr;
 182         struct buffer_head *bh;
 183         __u32 part_len;
 184
 185         mutex_lock(&sbi->s_alloc_mutex);
 186         part_len = sbi->s_partmaps[partition].s_partition_len;
 187         if (first_block >= part_len)
 188                 goto out;
 189
 190         if (first_block + block_count > part_len)
 191                 block_count = part_len - first_block;
 192
 193         do {
 194                 nr_groups = udf_compute_nr_groups(sb, partition);
 195                 block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 196                 block_group = block >> (sb->s_blocksize_bits + 3);
 197                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 198
 199                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 200                 if (bitmap_nr < 0)
 201                         goto out;
 202                 bh = bitmap->s_block_bitmap[bitmap_nr];
 203
 204                 bit = block % (sb->s_blocksize << 3);
 205
 206                 while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 207                         if (!udf_clear_bit(bit, bh->b_data))
 208                                 goto out;
 209                         block_count--;
 210                         alloc_count++;
 211                         bit++;
 212                         block++;
 213                 }
 214                 mark_buffer_dirty(bh);
 215         } while (block_count > 0);
 216
 217 out:
 218         udf_add_free_space(sb, partition, -alloc_count);
 219         mutex_unlock(&sbi->s_alloc_mutex);
 220         return alloc_count;
 221 }
 222
 223 static int udf_bitmap_new_block(struct super_block *sb,
 224                                 struct udf_bitmap *bitmap, uint16_t partition,
 225                                 uint32_t goal, int *err)
 226 {
 227         struct udf_sb_info *sbi = UDF_SB(sb);
 228         int newbit, bit = 0, block, block_group, group_start;
 229         int end_goal, nr_groups, bitmap_nr, i;
 230         struct buffer_head *bh = NULL;
 231         char *ptr;
 232         int newblock = 0;
 233
 234         *err = -ENOSPC;
 235         mutex_lock(&sbi->s_alloc_mutex);
 236
 237 repeat:
 238         if (goal >= sbi->s_partmaps[partition].s_partition_len)
 239                 goal = 0;
 240
 241         nr_groups = bitmap->s_nr_groups;
 242         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 243         block_group = block >> (sb->s_blocksize_bits + 3);
 244         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 245
 246         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 247         if (bitmap_nr < 0)
 248                 goto error_return;
 249         bh = bitmap->s_block_bitmap[bitmap_nr];
 250         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 251                       sb->s_blocksize - group_start);
 252
 253         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 254                 bit = block % (sb->s_blocksize << 3);
 255                 if (udf_test_bit(bit, bh->b_data))
 256                         goto got_block;
 257
 258                 end_goal = (bit + 63) & ~63;
 259                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 260                 if (bit < end_goal)
 261                         goto got_block;
 262
 263                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
 264                               sb->s_blocksize - ((bit + 7) >> 3));
 265                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 266                 if (newbit < sb->s_blocksize << 3) {
 267                         bit = newbit;
 268                         goto search_back;
 269                 }
 270
 271                 newbit = udf_find_next_one_bit(bh->b_data,
 272                                                sb->s_blocksize << 3, bit);
 273                 if (newbit < sb->s_blocksize << 3) {
 274                         bit = newbit;
 275                         goto got_block;
 276                 }
 277         }
 278
 279         for (i = 0; i < (nr_groups * 2); i++) {
 280                 block_group++;
 281                 if (block_group >= nr_groups)
 282                         block_group = 0;
 283                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 284
 285                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 286                 if (bitmap_nr < 0)
 287                         goto error_return;
 288                 bh = bitmap->s_block_bitmap[bitmap_nr];
 289                 if (i < nr_groups) {
 290                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 291                                       sb->s_blocksize - group_start);
 292                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 293                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 294                                 break;
 295                         }
 296                 } else {
 297                         bit = udf_find_next_one_bit(bh->b_data,
 298                                                     sb->s_blocksize << 3,
 299                                                     group_start << 3);
 300                         if (bit < sb->s_blocksize << 3)
 301                                 break;
 302                 }
 303         }
 304         if (i >= (nr_groups * 2)) {
 305                 mutex_unlock(&sbi->s_alloc_mutex);
 306                 return newblock;
 307         }
 308         if (bit < sb->s_blocksize << 3)
 309                 goto search_back;
 310         else
 311                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
 312                                             group_start << 3);
 313         if (bit >= sb->s_blocksize << 3) {
 314                 mutex_unlock(&sbi->s_alloc_mutex);
 315                 return 0;
 316         }
 317
 318 search_back:
 319         i = 0;
 320         while (i < 7 && bit > (group_start << 3) &&
 321                udf_test_bit(bit - 1, bh->b_data)) {
 322                 ++i;
 323                 --bit;
 324         }
 325
 326 got_block:
 327         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 328                 (sizeof(struct spaceBitmapDesc) << 3);
 329
 330         if (!udf_clear_bit(bit, bh->b_data)) {
 331                 udf_debug("bit already cleared for block %d\n", bit);
 332                 goto repeat;
 333         }
 334
 335         mark_buffer_dirty(bh);
 336
 337         udf_add_free_space(sb, partition, -1);
 338         mutex_unlock(&sbi->s_alloc_mutex);
 339         *err = 0;
 340         return newblock;
 341
 342 error_return:
 343         *err = -EIO;
 344         mutex_unlock(&sbi->s_alloc_mutex);
 345         return 0;
 346 }
 347
 348 static void udf_table_free_blocks(struct super_block *sb,
 349                                   struct inode *table,
 350                                   struct kernel_lb_addr *bloc,
 351                                   uint32_t offset,
 352                                   uint32_t count)
 353 {
 354         struct udf_sb_info *sbi = UDF_SB(sb);
 355         struct udf_part_map *partmap;
 356         uint32_t start, end;
 357         uint32_t elen;
 358         struct kernel_lb_addr eloc;
 359         struct extent_position oepos, epos;
 360         int8_t etype;
 361         int i;
 362         struct udf_inode_info *iinfo;
 363
 364         mutex_lock(&sbi->s_alloc_mutex);
 365         partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 366         if (bloc->logicalBlockNum + count < count ||
 367             (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
 368                 udf_debug("%d < %d || %d + %d > %d\n",
 369                           bloc->logicalBlockNum, 0,
 370                           bloc->logicalBlockNum, count,
 371                           partmap->s_partition_len);
 372                 goto error_return;
 373         }
 374
 375         iinfo = UDF_I(table);
 376         udf_add_free_space(sb, sbi->s_partition, count);
 377
 378         start = bloc->logicalBlockNum + offset;
 379         end = bloc->logicalBlockNum + offset + count - 1;
 380
 381         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 382         elen = 0;
 383         epos.block = oepos.block = iinfo->i_location;
 384         epos.bh = oepos.bh = NULL;
 385
 386         while (count &&
 387                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 388                 if (((eloc.logicalBlockNum +
 389                         (elen >> sb->s_blocksize_bits)) == start)) {
 390                         if ((0x3FFFFFFF - elen) <
 391                                         (count << sb->s_blocksize_bits)) {
 392                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 393                                                         sb->s_blocksize_bits);
 394                                 count -= tmp;
 395                                 start += tmp;
 396                                 elen = (etype << 30) |
 397                                         (0x40000000 - sb->s_blocksize);
 398                         } else {
 399                                 elen = (etype << 30) |
 400                                         (elen +
 401                                         (count << sb->s_blocksize_bits));
 402                                 start += count;
 403                                 count = 0;
 404                         }
 405                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 406                 } else if (eloc.logicalBlockNum == (end + 1)) {
 407                         if ((0x3FFFFFFF - elen) <
 408                                         (count << sb->s_blocksize_bits)) {
 409                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 410                                                 sb->s_blocksize_bits);
 411                                 count -= tmp;
 412                                 end -= tmp;
 413                                 eloc.logicalBlockNum -= tmp;
 414                                 elen = (etype << 30) |
 415                                         (0x40000000 - sb->s_blocksize);
 416                         } else {
 417                                 eloc.logicalBlockNum = start;
 418                                 elen = (etype << 30) |
 419                                         (elen +
 420                                         (count << sb->s_blocksize_bits));
 421                                 end -= count;
 422                                 count = 0;
 423                         }
 424                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 425                 }
 426
 427                 if (epos.bh != oepos.bh) {
 428                         i = -1;
 429                         oepos.block = epos.block;
 430                         brelse(oepos.bh);
 431                         get_bh(epos.bh);
 432                         oepos.bh = epos.bh;
 433                         oepos.offset = 0;
 434                 } else {
 435                         oepos.offset = epos.offset;
 436                 }
 437         }
 438
 439         if (count) {
 440                 /*
 441                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
 442                  * allocate a new block, and since we hold the super block
 443                  * lock already very bad things would happen :)
 444                  *
 445                  * We copy the behavior of udf_add_aext, but instead of
 446                  * trying to allocate a new block close to the existing one,
 447                  * we just steal a block from the extent we are trying to add.
 448                  *
 449                  * It would be nice if the blocks were close together, but it
 450                  * isn't required.
 451                  */
 452
 453                 int adsize;
 454                 struct short_ad *sad = NULL;
 455                 struct long_ad *lad = NULL;
 456                 struct allocExtDesc *aed;
 457
 458                 eloc.logicalBlockNum = start;
 459                 elen = EXT_RECORDED_ALLOCATED |
 460                         (count << sb->s_blocksize_bits);
 461
 462                 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 463                         adsize = sizeof(struct short_ad);
 464                 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 465                         adsize = sizeof(struct long_ad);
 466                 else {
 467                         brelse(oepos.bh);
 468                         brelse(epos.bh);
 469                         goto error_return;
 470                 }
 471
 472                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 473                         unsigned char *sptr, *dptr;
 474                         int loffset;
 475
 476                         brelse(oepos.bh);
 477                         oepos = epos;
 478
 479                         /* Steal a block from the extent being free'd */
 480                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 481                         eloc.logicalBlockNum++;
 482                         elen -= sb->s_blocksize;
 483
 484                         epos.bh = udf_tread(sb,
 485                                         udf_get_lb_pblock(sb, &epos.block, 0));
 486                         if (!epos.bh) {
 487                                 brelse(oepos.bh);
 488                                 goto error_return;
 489                         }
 490                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 491                         aed->previousAllocExtLocation =
 492                                 cpu_to_le32(oepos.block.logicalBlockNum);
 493                         if (epos.offset + adsize > sb->s_blocksize) {
 494                                 loffset = epos.offset;
 495                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 496                                 sptr = iinfo->i_ext.i_data + epos.offset
 497                                                                 - adsize;
 498                                 dptr = epos.bh->b_data +
 499                                         sizeof(struct allocExtDesc);
 500                                 memcpy(dptr, sptr, adsize);
 501                                 epos.offset = sizeof(struct allocExtDesc) +
 502                                                 adsize;
 503                         } else {
 504                                 loffset = epos.offset + adsize;
 505                                 aed->lengthAllocDescs = cpu_to_le32(0);
 506                                 if (oepos.bh) {
 507                                         sptr = oepos.bh->b_data + epos.offset;
 508                                         aed = (struct allocExtDesc *)
 509                                                 oepos.bh->b_data;
 510                                         le32_add_cpu(&aed->lengthAllocDescs,
 511                                                         adsize);
 512                                 } else {
 513                                         sptr = iinfo->i_ext.i_data +
 514                                                                 epos.offset;
 515                                         iinfo->i_lenAlloc += adsize;
 516                                         mark_inode_dirty(table);
 517                                 }
 518                                 epos.offset = sizeof(struct allocExtDesc);
 519                         }
 520                         if (sbi->s_udfrev >= 0x0200)
 521                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 522                                             3, 1, epos.block.logicalBlockNum,
 523                                             sizeof(struct tag));
 524                         else
 525                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 526                                             2, 1, epos.block.logicalBlockNum,
 527                                             sizeof(struct tag));
 528
 529                         switch (iinfo->i_alloc_type) {
 530                         case ICBTAG_FLAG_AD_SHORT:
 531                                 sad = (struct short_ad *)sptr;
 532                                 sad->extLength = cpu_to_le32(
 533                                         EXT_NEXT_EXTENT_ALLOCDECS |
 534                                         sb->s_blocksize);
 535                                 sad->extPosition =
 536                                         cpu_to_le32(epos.block.logicalBlockNum);
 537                                 break;
 538                         case ICBTAG_FLAG_AD_LONG:
 539                                 lad = (struct long_ad *)sptr;
 540                                 lad->extLength = cpu_to_le32(
 541                                         EXT_NEXT_EXTENT_ALLOCDECS |
 542                                         sb->s_blocksize);
 543                                 lad->extLocation =
 544                                         cpu_to_lelb(epos.block);
 545                                 break;
 546                         }
 547                         if (oepos.bh) {
 548                                 udf_update_tag(oepos.bh->b_data, loffset);
 549                                 mark_buffer_dirty(oepos.bh);
 550                         } else {
 551                                 mark_inode_dirty(table);
 552                         }
 553                 }
 554
 555                 /* It's possible that stealing the block emptied the extent */
 556                 if (elen) {
 557                         udf_write_aext(table, &epos, &eloc, elen, 1);
 558
 559                         if (!epos.bh) {
 560                                 iinfo->i_lenAlloc += adsize;
 561                                 mark_inode_dirty(table);
 562                         } else {
 563                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 564                                 le32_add_cpu(&aed->lengthAllocDescs, adsize);
 565                                 udf_update_tag(epos.bh->b_data, epos.offset);
 566                                 mark_buffer_dirty(epos.bh);
 567                         }
 568                 }
 569         }
 570
 571         brelse(epos.bh);
 572         brelse(oepos.bh);
 573
 574 error_return:
 575         mutex_unlock(&sbi->s_alloc_mutex);
 576         return;
 577 }
 578
 579 static int udf_table_prealloc_blocks(struct super_block *sb,
 580                                      struct inode *table, uint16_t partition,
 581                                      uint32_t first_block, uint32_t block_count)
 582 {
 583         struct udf_sb_info *sbi = UDF_SB(sb);
 584         int alloc_count = 0;
 585         uint32_t elen, adsize;
 586         struct kernel_lb_addr eloc;
 587         struct extent_position epos;
 588         int8_t etype = -1;
 589         struct udf_inode_info *iinfo;
 590
 591         if (first_block >= sbi->s_partmaps[partition].s_partition_len)
 592                 return 0;
 593
 594         iinfo = UDF_I(table);
 595         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 596                 adsize = sizeof(struct short_ad);
 597         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 598                 adsize = sizeof(struct long_ad);
 599         else
 600                 return 0;
 601
 602         mutex_lock(&sbi->s_alloc_mutex);
 603         epos.offset = sizeof(struct unallocSpaceEntry);
 604         epos.block = iinfo->i_location;
 605         epos.bh = NULL;
 606         eloc.logicalBlockNum = 0xFFFFFFFF;
 607
 608         while (first_block != eloc.logicalBlockNum &&
 609                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 610                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 611                           eloc.logicalBlockNum, elen, first_block);
 612                 ; /* empty loop body */
 613         }
 614
 615         if (first_block == eloc.logicalBlockNum) {
 616                 epos.offset -= adsize;
 617
 618                 alloc_count = (elen >> sb->s_blocksize_bits);
 619                 if (alloc_count > block_count) {
 620                         alloc_count = block_count;
 621                         eloc.logicalBlockNum += alloc_count;
 622                         elen -= (alloc_count << sb->s_blocksize_bits);
 623                         udf_write_aext(table, &epos, &eloc,
 624                                         (etype << 30) | elen, 1);
 625                 } else
 626                         udf_delete_aext(table, epos, eloc,
 627                                         (etype << 30) | elen);
 628         } else {
 629                 alloc_count = 0;
 630         }
 631
 632         brelse(epos.bh);
 633
 634         if (alloc_count)
 635                 udf_add_free_space(sb, partition, -alloc_count);
 636         mutex_unlock(&sbi->s_alloc_mutex);
 637         return alloc_count;
 638 }
 639
 640 static int udf_table_new_block(struct super_block *sb,
 641                                struct inode *table, uint16_t partition,
 642                                uint32_t goal, int *err)
 643 {
 644         struct udf_sb_info *sbi = UDF_SB(sb);
 645         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 646         uint32_t newblock = 0, adsize;
 647         uint32_t elen, goal_elen = 0;
 648         struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 649         struct extent_position epos, goal_epos;
 650         int8_t etype;
 651         struct udf_inode_info *iinfo = UDF_I(table);
 652
 653         *err = -ENOSPC;
 654
 655         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 656                 adsize = sizeof(struct short_ad);
 657         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 658                 adsize = sizeof(struct long_ad);
 659         else
 660                 return newblock;
 661
 662         mutex_lock(&sbi->s_alloc_mutex);
 663         if (goal >= sbi->s_partmaps[partition].s_partition_len)
 664                 goal = 0;
 665
 666         /* We search for the closest matching block to goal. If we find
 667            a exact hit, we stop. Otherwise we keep going till we run out
 668            of extents. We store the buffer_head, bloc, and extoffset
 669            of the current closest match and use that when we are done.
 670          */
 671         epos.offset = sizeof(struct unallocSpaceEntry);
 672         epos.block = iinfo->i_location;
 673         epos.bh = goal_epos.bh = NULL;
 674
 675         while (spread &&
 676                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 677                 if (goal >= eloc.logicalBlockNum) {
 678                         if (goal < eloc.logicalBlockNum +
 679                                         (elen >> sb->s_blocksize_bits))
 680                                 nspread = 0;
 681                         else
 682                                 nspread = goal - eloc.logicalBlockNum -
 683                                         (elen >> sb->s_blocksize_bits);
 684                 } else {
 685                         nspread = eloc.logicalBlockNum - goal;
 686                 }
 687
 688                 if (nspread < spread) {
 689                         spread = nspread;
 690                         if (goal_epos.bh != epos.bh) {
 691                                 brelse(goal_epos.bh);
 692                                 goal_epos.bh = epos.bh;
 693                                 get_bh(goal_epos.bh);
 694                         }
 695                         goal_epos.block = epos.block;
 696                         goal_epos.offset = epos.offset - adsize;
 697                         goal_eloc = eloc;
 698                         goal_elen = (etype << 30) | elen;
 699                 }
 700         }
 701
 702         brelse(epos.bh);
 703
 704         if (spread == 0xFFFFFFFF) {
 705                 brelse(goal_epos.bh);
 706                 mutex_unlock(&sbi->s_alloc_mutex);
 707                 return 0;
 708         }
 709
 710         /* Only allocate blocks from the beginning of the extent.
 711            That way, we only delete (empty) extents, never have to insert an
 712            extent because of splitting */
 713         /* This works, but very poorly.... */
 714
 715         newblock = goal_eloc.logicalBlockNum;
 716         goal_eloc.logicalBlockNum++;
 717         goal_elen -= sb->s_blocksize;
 718
 719         if (goal_elen)
 720                 udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
 721         else
 722                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 723         brelse(goal_epos.bh);
 724
 725         udf_add_free_space(sb, partition, -1);
 726
 727         mutex_unlock(&sbi->s_alloc_mutex);
 728         *err = 0;
 729         return newblock;
 730 }
 731
 732 void udf_free_blocks(struct super_block *sb, struct inode *inode,
 733                      struct kernel_lb_addr *bloc, uint32_t offset,
 734                      uint32_t count)
 735 {
 736         uint16_t partition = bloc->partitionReferenceNum;
 737         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 738
 739         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 740                 udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,
 741                                        bloc, offset, count);
 742         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 743                 udf_table_free_blocks(sb, map->s_uspace.s_table,
 744                                       bloc, offset, count);
 745         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 746                 udf_bitmap_free_blocks(sb, map->s_fspace.s_bitmap,
 747                                        bloc, offset, count);
 748         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 749                 udf_table_free_blocks(sb, map->s_fspace.s_table,
 750                                       bloc, offset, count);
 751         }
 752
 753         if (inode) {
 754                 inode_sub_bytes(inode,
 755                                 ((sector_t)count) << sb->s_blocksize_bits);
 756         }
 757 }
 758
 759 inline int udf_prealloc_blocks(struct super_block *sb,
 760                                struct inode *inode,
 761                                uint16_t partition, uint32_t first_block,
 762                                uint32_t block_count)
 763 {
 764         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 765         sector_t allocated;
 766
 767         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 768                 allocated = udf_bitmap_prealloc_blocks(sb,
 769                                                        map->s_uspace.s_bitmap,
 770                                                        partition, first_block,
 771                                                        block_count);
 772         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 773                 allocated = udf_table_prealloc_blocks(sb,
 774                                                       map->s_uspace.s_table,
 775                                                       partition, first_block,
 776                                                       block_count);
 777         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 778                 allocated = udf_bitmap_prealloc_blocks(sb,
 779                                                        map->s_fspace.s_bitmap,
 780                                                        partition, first_block,
 781                                                        block_count);
 782         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 783                 allocated = udf_table_prealloc_blocks(sb,
 784                                                       map->s_fspace.s_table,
 785                                                       partition, first_block,
 786                                                       block_count);
 787         else
 788                 return 0;
 789
 790         if (inode && allocated > 0)
 791                 inode_add_bytes(inode, allocated << sb->s_blocksize_bits);
 792         return allocated;
 793 }
 794
 795 inline int udf_new_block(struct super_block *sb,
 796                          struct inode *inode,
 797                          uint16_t partition, uint32_t goal, int *err)
 798 {
 799         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 800         int block;
 801
 802         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 803                 block = udf_bitmap_new_block(sb,
 804                                              map->s_uspace.s_bitmap,
 805                                              partition, goal, err);
 806         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 807                 block = udf_table_new_block(sb,
 808                                             map->s_uspace.s_table,
 809                                             partition, goal, err);
 810         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 811                 block = udf_bitmap_new_block(sb,
 812                                              map->s_fspace.s_bitmap,
 813                                              partition, goal, err);
 814         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 815                 block = udf_table_new_block(sb,
 816                                             map->s_fspace.s_table,
 817                                             partition, goal, err);
 818         else {
 819                 *err = -EIO;
 820                 return 0;
 821         }
 822         if (inode && block)
 823                 inode_add_bytes(inode, sb->s_blocksize);
 824         return block;
 825 }