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/quotaops.h>
  25 #include <linux/buffer_head.h>
  26 #include <linux/bitops.h>
  27
  28 #include "udf_i.h"
  29 #include "udf_sb.h"
  30
  31 #define udf_clear_bit(nr,addr) ext2_clear_bit(nr,addr)
  32 #define udf_set_bit(nr,addr) ext2_set_bit(nr,addr)
  33 #define udf_test_bit(nr, addr) ext2_test_bit(nr, addr)
  34 #define udf_find_first_one_bit(addr, size) find_first_one_bit(addr, size)
  35 #define udf_find_next_one_bit(addr, size, offset) find_next_one_bit(addr, size, offset)
  36
  37 #define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x)
  38 #define leNUM_to_cpup(x,y) xleNUM_to_cpup(x,y)
  39 #define xleNUM_to_cpup(x,y) (le ## x ## _to_cpup(y))
  40 #define uintBPL_t uint(BITS_PER_LONG)
  41 #define uint(x) xuint(x)
  42 #define xuint(x) __le ## x
  43
  44 static inline int find_next_one_bit (void * addr, int size, int offset)
  45 {
  46         uintBPL_t * p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG);
  47         int result = offset & ~(BITS_PER_LONG-1);
  48         unsigned long tmp;
  49
  50         if (offset >= size)
  51                 return size;
  52         size -= result;
  53         offset &= (BITS_PER_LONG-1);
  54         if (offset)
  55         {
  56                 tmp = leBPL_to_cpup(p++);
  57                 tmp &= ~0UL << offset;
  58                 if (size < BITS_PER_LONG)
  59                         goto found_first;
  60                 if (tmp)
  61                         goto found_middle;
  62                 size -= BITS_PER_LONG;
  63                 result += BITS_PER_LONG;
  64         }
  65         while (size & ~(BITS_PER_LONG-1))
  66         {
  67                 if ((tmp = leBPL_to_cpup(p++)))
  68                         goto found_middle;
  69                 result += BITS_PER_LONG;
  70                 size -= BITS_PER_LONG;
  71         }
  72         if (!size)
  73                 return result;
  74         tmp = leBPL_to_cpup(p);
  75 found_first:
  76         tmp &= ~0UL >> (BITS_PER_LONG-size);
  77 found_middle:
  78         return result + ffz(~tmp);
  79 }
  80
  81 #define find_first_one_bit(addr, size)\
  82         find_next_one_bit((addr), (size), 0)
  83
  84 static int read_block_bitmap(struct super_block * sb,
  85         struct udf_bitmap *bitmap, unsigned int block, unsigned long bitmap_nr)
  86 {
  87         struct buffer_head *bh = NULL;
  88         int retval = 0;
  89         kernel_lb_addr loc;
  90
  91         loc.logicalBlockNum = bitmap->s_extPosition;
  92         loc.partitionReferenceNum = UDF_SB_PARTITION(sb);
  93
  94         bh = udf_tread(sb, udf_get_lb_pblock(sb, loc, block));
  95         if (!bh)
  96         {
  97                 retval = -EIO;
  98         }
  99         bitmap->s_block_bitmap[bitmap_nr] = bh;
 100         return retval;
 101 }
 102
 103 static int __load_block_bitmap(struct super_block * sb,
 104         struct udf_bitmap *bitmap, unsigned int block_group)
 105 {
 106         int retval = 0;
 107         int nr_groups = bitmap->s_nr_groups;
 108
 109         if (block_group >= nr_groups)
 110         {
 111                 udf_debug("block_group (%d) > nr_groups (%d)\n", block_group, nr_groups);
 112         }
 113
 114         if (bitmap->s_block_bitmap[block_group])
 115                 return block_group;
 116         else
 117         {
 118                 retval = read_block_bitmap(sb, bitmap, block_group, block_group);
 119                 if (retval < 0)
 120                         return retval;
 121                 return block_group;
 122         }
 123 }
 124
 125 static inline int load_block_bitmap(struct super_block * sb,
 126         struct udf_bitmap *bitmap, unsigned int block_group)
 127 {
 128         int slot;
 129
 130         slot = __load_block_bitmap(sb, bitmap, block_group);
 131
 132         if (slot < 0)
 133                 return slot;
 134
 135         if (!bitmap->s_block_bitmap[slot])
 136                 return -EIO;
 137
 138         return slot;
 139 }
 140
 141 static void udf_bitmap_free_blocks(struct super_block * sb,
 142         struct inode * inode,
 143         struct udf_bitmap *bitmap,
 144         kernel_lb_addr bloc, uint32_t offset, uint32_t count)
 145 {
 146         struct udf_sb_info *sbi = UDF_SB(sb);
 147         struct buffer_head * bh = NULL;
 148         unsigned long block;
 149         unsigned long block_group;
 150         unsigned long bit;
 151         unsigned long i;
 152         int bitmap_nr;
 153         unsigned long overflow;
 154
 155         mutex_lock(&sbi->s_alloc_mutex);
 156         if (bloc.logicalBlockNum < 0 ||
 157                 (bloc.logicalBlockNum + count) > UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum))
 158         {
 159                 udf_debug("%d < %d || %d + %d > %d\n",
 160                         bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 161                         UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum));
 162                 goto error_return;
 163         }
 164
 165         block = bloc.logicalBlockNum + offset + (sizeof(struct spaceBitmapDesc) << 3);
 166
 167 do_more:
 168         overflow = 0;
 169         block_group = block >> (sb->s_blocksize_bits + 3);
 170         bit = block % (sb->s_blocksize << 3);
 171
 172         /*
 173          * Check to see if we are freeing blocks across a group boundary.
 174          */
 175         if (bit + count > (sb->s_blocksize << 3))
 176         {
 177                 overflow = bit + count - (sb->s_blocksize << 3);
 178                 count -= overflow;
 179         }
 180         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 181         if (bitmap_nr < 0)
 182                 goto error_return;
 183
 184         bh = bitmap->s_block_bitmap[bitmap_nr];
 185         for (i=0; i < count; i++)
 186         {
 187                 if (udf_set_bit(bit + i, bh->b_data))
 188                 {
 189                         udf_debug("bit %ld already set\n", bit + i);
 190                         udf_debug("byte=%2x\n", ((char *)bh->b_data)[(bit + i) >> 3]);
 191                 }
 192                 else
 193                 {
 194                         if (inode)
 195                                 DQUOT_FREE_BLOCK(inode, 1);
 196                         if (UDF_SB_LVIDBH(sb))
 197                         {
 198                                 UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)] =
 199                                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)])+1);
 200                         }
 201                 }
 202         }
 203         mark_buffer_dirty(bh);
 204         if (overflow)
 205         {
 206                 block += count;
 207                 count = overflow;
 208                 goto do_more;
 209         }
 210 error_return:
 211         sb->s_dirt = 1;
 212         if (UDF_SB_LVIDBH(sb))
 213                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 214         mutex_unlock(&sbi->s_alloc_mutex);
 215         return;
 216 }
 217
 218 static int udf_bitmap_prealloc_blocks(struct super_block * sb,
 219         struct inode * inode,
 220         struct udf_bitmap *bitmap, uint16_t partition, uint32_t first_block,
 221         uint32_t block_count)
 222 {
 223         struct udf_sb_info *sbi = UDF_SB(sb);
 224         int alloc_count = 0;
 225         int bit, block, block_group, group_start;
 226         int nr_groups, bitmap_nr;
 227         struct buffer_head *bh;
 228
 229         mutex_lock(&sbi->s_alloc_mutex);
 230         if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
 231                 goto out;
 232
 233         if (first_block + block_count > UDF_SB_PARTLEN(sb, partition))
 234                 block_count = UDF_SB_PARTLEN(sb, partition) - first_block;
 235
 236 repeat:
 237         nr_groups = (UDF_SB_PARTLEN(sb, partition) +
 238                 (sizeof(struct spaceBitmapDesc) << 3) + (sb->s_blocksize * 8) - 1) / (sb->s_blocksize * 8);
 239         block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 240         block_group = block >> (sb->s_blocksize_bits + 3);
 241         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 242
 243         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 244         if (bitmap_nr < 0)
 245                 goto out;
 246         bh = bitmap->s_block_bitmap[bitmap_nr];
 247
 248         bit = block % (sb->s_blocksize << 3);
 249
 250         while (bit < (sb->s_blocksize << 3) && block_count > 0)
 251         {
 252                 if (!udf_test_bit(bit, bh->b_data))
 253                         goto out;
 254                 else if (DQUOT_PREALLOC_BLOCK(inode, 1))
 255                         goto out;
 256                 else if (!udf_clear_bit(bit, bh->b_data))
 257                 {
 258                         udf_debug("bit already cleared for block %d\n", bit);
 259                         DQUOT_FREE_BLOCK(inode, 1);
 260                         goto out;
 261                 }
 262                 block_count --;
 263                 alloc_count ++;
 264                 bit ++;
 265                 block ++;
 266         }
 267         mark_buffer_dirty(bh);
 268         if (block_count > 0)
 269                 goto repeat;
 270 out:
 271         if (UDF_SB_LVIDBH(sb))
 272         {
 273                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 274                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-alloc_count);
 275                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 276         }
 277         sb->s_dirt = 1;
 278         mutex_unlock(&sbi->s_alloc_mutex);
 279         return alloc_count;
 280 }
 281
 282 static int udf_bitmap_new_block(struct super_block * sb,
 283         struct inode * inode,
 284         struct udf_bitmap *bitmap, uint16_t partition, uint32_t goal, int *err)
 285 {
 286         struct udf_sb_info *sbi = UDF_SB(sb);
 287         int newbit, bit=0, block, block_group, group_start;
 288         int end_goal, nr_groups, bitmap_nr, i;
 289         struct buffer_head *bh = NULL;
 290         char *ptr;
 291         int newblock = 0;
 292
 293         *err = -ENOSPC;
 294         mutex_lock(&sbi->s_alloc_mutex);
 295
 296 repeat:
 297         if (goal < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
 298                 goal = 0;
 299
 300         nr_groups = bitmap->s_nr_groups;
 301         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 302         block_group = block >> (sb->s_blocksize_bits + 3);
 303         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 304
 305         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 306         if (bitmap_nr < 0)
 307                 goto error_return;
 308         bh = bitmap->s_block_bitmap[bitmap_nr];
 309         ptr = memscan((char *)bh->b_data + group_start, 0xFF, sb->s_blocksize - group_start);
 310
 311         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize)
 312         {
 313                 bit = block % (sb->s_blocksize << 3);
 314
 315                 if (udf_test_bit(bit, bh->b_data))
 316                 {
 317                         goto got_block;
 318                 }
 319                 end_goal = (bit + 63) & ~63;
 320                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 321                 if (bit < end_goal)
 322                         goto got_block;
 323                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF, sb->s_blocksize - ((bit + 7) >> 3));
 324                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 325                 if (newbit < sb->s_blocksize << 3)
 326                 {
 327                         bit = newbit;
 328                         goto search_back;
 329                 }
 330                 newbit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, bit);
 331                 if (newbit < sb->s_blocksize << 3)
 332                 {
 333                         bit = newbit;
 334                         goto got_block;
 335                 }
 336         }
 337
 338         for (i=0; i<(nr_groups*2); i++)
 339         {
 340                 block_group ++;
 341                 if (block_group >= nr_groups)
 342                         block_group = 0;
 343                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 344
 345                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 346                 if (bitmap_nr < 0)
 347                         goto error_return;
 348                 bh = bitmap->s_block_bitmap[bitmap_nr];
 349                 if (i < nr_groups)
 350                 {
 351                         ptr = memscan((char *)bh->b_data + group_start, 0xFF, sb->s_blocksize - group_start);
 352                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize)
 353                         {
 354                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 355                                 break;
 356                         }
 357                 }
 358                 else
 359                 {
 360                         bit = udf_find_next_one_bit((char *)bh->b_data, sb->s_blocksize << 3, group_start << 3);
 361                         if (bit < sb->s_blocksize << 3)
 362                                 break;
 363                 }
 364         }
 365         if (i >= (nr_groups*2))
 366         {
 367                 mutex_unlock(&sbi->s_alloc_mutex);
 368                 return newblock;
 369         }
 370         if (bit < sb->s_blocksize << 3)
 371                 goto search_back;
 372         else
 373                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, group_start << 3);
 374         if (bit >= sb->s_blocksize << 3)
 375         {
 376                 mutex_unlock(&sbi->s_alloc_mutex);
 377                 return 0;
 378         }
 379
 380 search_back:
 381         for (i=0; i<7 && bit > (group_start << 3) && udf_test_bit(bit - 1, bh->b_data); i++, bit--);
 382
 383 got_block:
 384
 385         /*
 386          * Check quota for allocation of this block.
 387          */
 388         if (inode && DQUOT_ALLOC_BLOCK(inode, 1))
 389         {
 390                 mutex_unlock(&sbi->s_alloc_mutex);
 391                 *err = -EDQUOT;
 392                 return 0;
 393         }
 394
 395         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 396                 (sizeof(struct spaceBitmapDesc) << 3);
 397
 398         if (!udf_clear_bit(bit, bh->b_data))
 399         {
 400                 udf_debug("bit already cleared for block %d\n", bit);
 401                 goto repeat;
 402         }
 403
 404         mark_buffer_dirty(bh);
 405
 406         if (UDF_SB_LVIDBH(sb))
 407         {
 408                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 409                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-1);
 410                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 411         }
 412         sb->s_dirt = 1;
 413         mutex_unlock(&sbi->s_alloc_mutex);
 414         *err = 0;
 415         return newblock;
 416
 417 error_return:
 418         *err = -EIO;
 419         mutex_unlock(&sbi->s_alloc_mutex);
 420         return 0;
 421 }
 422
 423 static void udf_table_free_blocks(struct super_block * sb,
 424         struct inode * inode,
 425         struct inode * table,
 426         kernel_lb_addr bloc, uint32_t offset, uint32_t count)
 427 {
 428         struct udf_sb_info *sbi = UDF_SB(sb);
 429         uint32_t start, end;
 430         uint32_t elen;
 431         kernel_lb_addr eloc;
 432         struct extent_position oepos, epos;
 433         int8_t etype;
 434         int i;
 435
 436         mutex_lock(&sbi->s_alloc_mutex);
 437         if (bloc.logicalBlockNum < 0 ||
 438                 (bloc.logicalBlockNum + count) > UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum))
 439         {
 440                 udf_debug("%d < %d || %d + %d > %d\n",
 441                         bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 442                         UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum));
 443                 goto error_return;
 444         }
 445
 446         /* We do this up front - There are some error conditions that could occure,
 447            but.. oh well */
 448         if (inode)
 449                 DQUOT_FREE_BLOCK(inode, count);
 450         if (UDF_SB_LVIDBH(sb))
 451         {
 452                 UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)] =
 453                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)])+count);
 454                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 455         }
 456
 457         start = bloc.logicalBlockNum + offset;
 458         end = bloc.logicalBlockNum + offset + count - 1;
 459
 460         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 461         elen = 0;
 462         epos.block = oepos.block = UDF_I_LOCATION(table);
 463         epos.bh = oepos.bh = NULL;
 464
 465         while (count && (etype =
 466                 udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1)
 467         {
 468                 if (((eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits)) ==
 469                         start))
 470                 {
 471                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits))
 472                         {
 473                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 474                                 start += ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 475                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 476                         }
 477                         else
 478                         {
 479                                 elen = (etype << 30) |
 480                                         (elen + (count << sb->s_blocksize_bits));
 481                                 start += count;
 482                                 count = 0;
 483                         }
 484                         udf_write_aext(table, &oepos, eloc, elen, 1);
 485                 }
 486                 else if (eloc.logicalBlockNum == (end + 1))
 487                 {
 488                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits))
 489                         {
 490                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 491                                 end -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 492                                 eloc.logicalBlockNum -=
 493                                         ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 494                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 495                         }
 496                         else
 497                         {
 498                                 eloc.logicalBlockNum = start;
 499                                 elen = (etype << 30) |
 500                                         (elen + (count << sb->s_blocksize_bits));
 501                                 end -= count;
 502                                 count = 0;
 503                         }
 504                         udf_write_aext(table, &oepos, eloc, elen, 1);
 505                 }
 506
 507                 if (epos.bh != oepos.bh)
 508                 {
 509                         i = -1;
 510                         oepos.block = epos.block;
 511                         brelse(oepos.bh);
 512                         get_bh(epos.bh);
 513                         oepos.bh = epos.bh;
 514                         oepos.offset = 0;
 515                 }
 516                 else
 517                         oepos.offset = epos.offset;
 518         }
 519
 520         if (count)
 521         {
 522                 /* NOTE: we CANNOT use udf_add_aext here, as it can try to allocate
 523                                  a new block, and since we hold the super block lock already
 524                                  very bad things would happen :)
 525
 526                                  We copy the behavior of udf_add_aext, but instead of
 527                                  trying to allocate a new block close to the existing one,
 528                                  we just steal a block from the extent we are trying to add.
 529
 530                                  It would be nice if the blocks were close together, but it
 531                                  isn't required.
 532                 */
 533
 534                 int adsize;
 535                 short_ad *sad = NULL;
 536                 long_ad *lad = NULL;
 537                 struct allocExtDesc *aed;
 538
 539                 eloc.logicalBlockNum = start;
 540                 elen = EXT_RECORDED_ALLOCATED |
 541                         (count << sb->s_blocksize_bits);
 542
 543                 if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 544                         adsize = sizeof(short_ad);
 545                 else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 546                         adsize = sizeof(long_ad);
 547                 else
 548                 {
 549                         brelse(oepos.bh);
 550                         brelse(epos.bh);
 551                         goto error_return;
 552                 }
 553
 554                 if (epos.offset + (2 * adsize) > sb->s_blocksize)
 555                 {
 556                         char *sptr, *dptr;
 557                         int loffset;
 558
 559                         brelse(oepos.bh);
 560                         oepos = epos;
 561
 562                         /* Steal a block from the extent being free'd */
 563                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 564                         eloc.logicalBlockNum ++;
 565                         elen -= sb->s_blocksize;
 566
 567                         if (!(epos.bh = udf_tread(sb,
 568                                 udf_get_lb_pblock(sb, epos.block, 0))))
 569                         {
 570                                 brelse(oepos.bh);
 571                                 goto error_return;
 572                         }
 573                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 574                         aed->previousAllocExtLocation = cpu_to_le32(oepos.block.logicalBlockNum);
 575                         if (epos.offset + adsize > sb->s_blocksize)
 576                         {
 577                                 loffset = epos.offset;
 578                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 579                                 sptr = UDF_I_DATA(inode) + epos.offset -
 580                                         udf_file_entry_alloc_offset(inode) +
 581                                         UDF_I_LENEATTR(inode) - adsize;
 582                                 dptr = epos.bh->b_data + sizeof(struct allocExtDesc);
 583                                 memcpy(dptr, sptr, adsize);
 584                                 epos.offset = sizeof(struct allocExtDesc) + adsize;
 585                         }
 586                         else
 587                         {
 588                                 loffset = epos.offset + adsize;
 589                                 aed->lengthAllocDescs = cpu_to_le32(0);
 590                                 sptr = oepos.bh->b_data + epos.offset;
 591                                 epos.offset = sizeof(struct allocExtDesc);
 592
 593                                 if (oepos.bh)
 594                                 {
 595                                         aed = (struct allocExtDesc *)oepos.bh->b_data;
 596                                         aed->lengthAllocDescs =
 597                                                 cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 598                                 }
 599                                 else
 600                                 {
 601                                         UDF_I_LENALLOC(table) += adsize;
 602                                         mark_inode_dirty(table);
 603                                 }
 604                         }
 605                         if (UDF_SB_UDFREV(sb) >= 0x0200)
 606                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 3, 1,
 607                                         epos.block.logicalBlockNum, sizeof(tag));
 608                         else
 609                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 2, 1,
 610                                         epos.block.logicalBlockNum, sizeof(tag));
 611                         switch (UDF_I_ALLOCTYPE(table))
 612                         {
 613                                 case ICBTAG_FLAG_AD_SHORT:
 614                                 {
 615                                         sad = (short_ad *)sptr;
 616                                         sad->extLength = cpu_to_le32(
 617                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 618                                                 sb->s_blocksize);
 619                                         sad->extPosition = cpu_to_le32(epos.block.logicalBlockNum);
 620                                         break;
 621                                 }
 622                                 case ICBTAG_FLAG_AD_LONG:
 623                                 {
 624                                         lad = (long_ad *)sptr;
 625                                         lad->extLength = cpu_to_le32(
 626                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 627                                                 sb->s_blocksize);
 628                                         lad->extLocation = cpu_to_lelb(epos.block);
 629                                         break;
 630                                 }
 631                         }
 632                         if (oepos.bh)
 633                         {
 634                                 udf_update_tag(oepos.bh->b_data, loffset);
 635                                 mark_buffer_dirty(oepos.bh);
 636                         }
 637                         else
 638                                 mark_inode_dirty(table);
 639                 }
 640
 641                 if (elen) /* It's possible that stealing the block emptied the extent */
 642                 {
 643                         udf_write_aext(table, &epos, eloc, elen, 1);
 644
 645                         if (!epos.bh)
 646                         {
 647                                 UDF_I_LENALLOC(table) += adsize;
 648                                 mark_inode_dirty(table);
 649                         }
 650                         else
 651                         {
 652                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 653                                 aed->lengthAllocDescs =
 654                                         cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 655                                 udf_update_tag(epos.bh->b_data, epos.offset);
 656                                 mark_buffer_dirty(epos.bh);
 657                         }
 658                 }
 659         }
 660
 661         brelse(epos.bh);
 662         brelse(oepos.bh);
 663
 664 error_return:
 665         sb->s_dirt = 1;
 666         mutex_unlock(&sbi->s_alloc_mutex);
 667         return;
 668 }
 669
 670 static int udf_table_prealloc_blocks(struct super_block * sb,
 671         struct inode * inode,
 672         struct inode *table, uint16_t partition, uint32_t first_block,
 673         uint32_t block_count)
 674 {
 675         struct udf_sb_info *sbi = UDF_SB(sb);
 676         int alloc_count = 0;
 677         uint32_t elen, adsize;
 678         kernel_lb_addr eloc;
 679         struct extent_position epos;
 680         int8_t etype = -1;
 681
 682         if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
 683                 return 0;
 684
 685         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 686                 adsize = sizeof(short_ad);
 687         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 688                 adsize = sizeof(long_ad);
 689         else
 690                 return 0;
 691
 692         mutex_lock(&sbi->s_alloc_mutex);
 693         epos.offset = sizeof(struct unallocSpaceEntry);
 694         epos.block = UDF_I_LOCATION(table);
 695         epos.bh = NULL;
 696         eloc.logicalBlockNum = 0xFFFFFFFF;
 697
 698         while (first_block != eloc.logicalBlockNum && (etype =
 699                 udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1)
 700         {
 701                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 702                         eloc.logicalBlockNum, elen, first_block);
 703                 ; /* empty loop body */
 704         }
 705
 706         if (first_block == eloc.logicalBlockNum)
 707         {
 708                 epos.offset -= adsize;
 709
 710                 alloc_count = (elen >> sb->s_blocksize_bits);
 711                 if (inode && DQUOT_PREALLOC_BLOCK(inode, alloc_count > block_count ? block_count : alloc_count))
 712                         alloc_count = 0;
 713                 else if (alloc_count > block_count)
 714                 {
 715                         alloc_count = block_count;
 716                         eloc.logicalBlockNum += alloc_count;
 717                         elen -= (alloc_count << sb->s_blocksize_bits);
 718                         udf_write_aext(table, &epos, eloc, (etype << 30) | elen, 1);
 719                 }
 720                 else
 721                         udf_delete_aext(table, epos, eloc, (etype << 30) | elen);
 722         }
 723         else
 724                 alloc_count = 0;
 725
 726         brelse(epos.bh);
 727
 728         if (alloc_count && UDF_SB_LVIDBH(sb))
 729         {
 730                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 731                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-alloc_count);
 732                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 733                 sb->s_dirt = 1;
 734         }
 735         mutex_unlock(&sbi->s_alloc_mutex);
 736         return alloc_count;
 737 }
 738
 739 static int udf_table_new_block(struct super_block * sb,
 740         struct inode * inode,
 741         struct inode *table, uint16_t partition, uint32_t goal, int *err)
 742 {
 743         struct udf_sb_info *sbi = UDF_SB(sb);
 744         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 745         uint32_t newblock = 0, adsize;
 746         uint32_t elen, goal_elen = 0;
 747         kernel_lb_addr eloc, goal_eloc;
 748         struct extent_position epos, goal_epos;
 749         int8_t etype;
 750
 751         *err = -ENOSPC;
 752
 753         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 754                 adsize = sizeof(short_ad);
 755         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 756                 adsize = sizeof(long_ad);
 757         else
 758                 return newblock;
 759
 760         mutex_lock(&sbi->s_alloc_mutex);
 761         if (goal < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
 762                 goal = 0;
 763
 764         /* We search for the closest matching block to goal. If we find a exact hit,
 765            we stop. Otherwise we keep going till we run out of extents.
 766            We store the buffer_head, bloc, and extoffset of the current closest
 767            match and use that when we are done.
 768         */
 769         epos.offset = sizeof(struct unallocSpaceEntry);
 770         epos.block = UDF_I_LOCATION(table);
 771         epos.bh = goal_epos.bh = NULL;
 772
 773         while (spread && (etype =
 774                 udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1)
 775         {
 776                 if (goal >= eloc.logicalBlockNum)
 777                 {
 778                         if (goal < eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits))
 779                                 nspread = 0;
 780                         else
 781                                 nspread = goal - eloc.logicalBlockNum -
 782                                         (elen >> sb->s_blocksize_bits);
 783                 }
 784                 else
 785                         nspread = eloc.logicalBlockNum - goal;
 786
 787                 if (nspread < spread)
 788                 {
 789                         spread = nspread;
 790                         if (goal_epos.bh != epos.bh)
 791                         {
 792                                 brelse(goal_epos.bh);
 793                                 goal_epos.bh = epos.bh;
 794                                 get_bh(goal_epos.bh);
 795                         }
 796                         goal_epos.block = epos.block;
 797                         goal_epos.offset = epos.offset - adsize;
 798                         goal_eloc = eloc;
 799                         goal_elen = (etype << 30) | elen;
 800                 }
 801         }
 802
 803         brelse(epos.bh);
 804
 805         if (spread == 0xFFFFFFFF)
 806         {
 807                 brelse(goal_epos.bh);
 808                 mutex_unlock(&sbi->s_alloc_mutex);
 809                 return 0;
 810         }
 811
 812         /* Only allocate blocks from the beginning of the extent.
 813            That way, we only delete (empty) extents, never have to insert an
 814            extent because of splitting */
 815         /* This works, but very poorly.... */
 816
 817         newblock = goal_eloc.logicalBlockNum;
 818         goal_eloc.logicalBlockNum ++;
 819         goal_elen -= sb->s_blocksize;
 820
 821         if (inode && DQUOT_ALLOC_BLOCK(inode, 1))
 822         {
 823                 brelse(goal_epos.bh);
 824                 mutex_unlock(&sbi->s_alloc_mutex);
 825                 *err = -EDQUOT;
 826                 return 0;
 827         }
 828
 829         if (goal_elen)
 830                 udf_write_aext(table, &goal_epos, goal_eloc, goal_elen, 1);
 831         else
 832                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 833         brelse(goal_epos.bh);
 834
 835         if (UDF_SB_LVIDBH(sb))
 836         {
 837                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 838                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-1);
 839                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 840         }
 841
 842         sb->s_dirt = 1;
 843         mutex_unlock(&sbi->s_alloc_mutex);
 844         *err = 0;
 845         return newblock;
 846 }
 847
 848 inline void udf_free_blocks(struct super_block * sb,
 849         struct inode * inode,
 850         kernel_lb_addr bloc, uint32_t offset, uint32_t count)
 851 {
 852         uint16_t partition = bloc.partitionReferenceNum;
 853
 854         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 855         {
 856                 return udf_bitmap_free_blocks(sb, inode,
 857                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 858                         bloc, offset, count);
 859         }
 860         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 861         {
 862                 return udf_table_free_blocks(sb, inode,
 863                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 864                         bloc, offset, count);
 865         }
 866         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 867         {
 868                 return udf_bitmap_free_blocks(sb, inode,
 869                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 870                         bloc, offset, count);
 871         }
 872         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 873         {
 874                 return udf_table_free_blocks(sb, inode,
 875                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 876                         bloc, offset, count);
 877         }
 878         else
 879                 return;
 880 }
 881
 882 inline int udf_prealloc_blocks(struct super_block * sb,
 883         struct inode * inode,
 884         uint16_t partition, uint32_t first_block, uint32_t block_count)
 885 {
 886         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 887         {
 888                 return udf_bitmap_prealloc_blocks(sb, inode,
 889                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 890                         partition, first_block, block_count);
 891         }
 892         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 893         {
 894                 return udf_table_prealloc_blocks(sb, inode,
 895                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 896                         partition, first_block, block_count);
 897         }
 898         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 899         {
 900                 return udf_bitmap_prealloc_blocks(sb, inode,
 901                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 902                         partition, first_block, block_count);
 903         }
 904         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 905         {
 906                 return udf_table_prealloc_blocks(sb, inode,
 907                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 908                         partition, first_block, block_count);
 909         }
 910         else
 911                 return 0;
 912 }
 913
 914 inline int udf_new_block(struct super_block * sb,
 915         struct inode * inode,
 916         uint16_t partition, uint32_t goal, int *err)
 917 {
 918         int ret;
 919
 920         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 921         {
 922                 ret = udf_bitmap_new_block(sb, inode,
 923                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 924                         partition, goal, err);
 925                 return ret;
 926         }
 927         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 928         {
 929                 return udf_table_new_block(sb, inode,
 930                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 931                         partition, goal, err);
 932         }
 933         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 934         {
 935                 return udf_bitmap_new_block(sb, inode,
 936                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 937                         partition, goal, err);
 938         }
 939         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 940         {
 941                 return udf_table_new_block(sb, inode,
 942                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 943                         partition, goal, err);
 944         }
 945         else
 946         {
 947                 *err = -EIO;
 948                 return 0;
 949         }
 950 }