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         down(&sbi->s_alloc_sem);
 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         up(&sbi->s_alloc_sem);
 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         down(&sbi->s_alloc_sem);
 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         up(&sbi->s_alloc_sem);
 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         down(&sbi->s_alloc_sem);
 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                 up(&sbi->s_alloc_sem);
 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                 up(&sbi->s_alloc_sem);
 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                 up(&sbi->s_alloc_sem);
 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         up(&sbi->s_alloc_sem);
 414         *err = 0;
 415         return newblock;
 416
 417 error_return:
 418         *err = -EIO;
 419         up(&sbi->s_alloc_sem);
 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 nextoffset, oextoffset, elen;
 431         kernel_lb_addr nbloc, obloc, eloc;
 432         struct buffer_head *obh, *nbh;
 433         int8_t etype;
 434         int i;
 435
 436         down(&sbi->s_alloc_sem);
 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         oextoffset = nextoffset = sizeof(struct unallocSpaceEntry);
 461         elen = 0;
 462         obloc = nbloc = UDF_I_LOCATION(table);
 463
 464         obh = nbh = NULL;
 465
 466         while (count && (etype =
 467                 udf_next_aext(table, &nbloc, &nextoffset, &eloc, &elen, &nbh, 1)) != -1)
 468         {
 469                 if (((eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits)) ==
 470                         start))
 471                 {
 472                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits))
 473                         {
 474                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 475                                 start += ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 476                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 477                         }
 478                         else
 479                         {
 480                                 elen = (etype << 30) |
 481                                         (elen + (count << sb->s_blocksize_bits));
 482                                 start += count;
 483                                 count = 0;
 484                         }
 485                         udf_write_aext(table, obloc, &oextoffset, eloc, elen, obh, 1);
 486                 }
 487                 else if (eloc.logicalBlockNum == (end + 1))
 488                 {
 489                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits))
 490                         {
 491                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 492                                 end -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 493                                 eloc.logicalBlockNum -=
 494                                         ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 495                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 496                         }
 497                         else
 498                         {
 499                                 eloc.logicalBlockNum = start;
 500                                 elen = (etype << 30) |
 501                                         (elen + (count << sb->s_blocksize_bits));
 502                                 end -= count;
 503                                 count = 0;
 504                         }
 505                         udf_write_aext(table, obloc, &oextoffset, eloc, elen, obh, 1);
 506                 }
 507
 508                 if (nbh != obh)
 509                 {
 510                         i = -1;
 511                         obloc = nbloc;
 512                         udf_release_data(obh);
 513                         atomic_inc(&nbh->b_count);
 514                         obh = nbh;
 515                         oextoffset = 0;
 516                 }
 517                 else
 518                         oextoffset = nextoffset;
 519         }
 520
 521         if (count)
 522         {
 523                 /* NOTE: we CANNOT use udf_add_aext here, as it can try to allocate
 524                                  a new block, and since we hold the super block lock already
 525                                  very bad things would happen :)
 526
 527                                  We copy the behavior of udf_add_aext, but instead of
 528                                  trying to allocate a new block close to the existing one,
 529                                  we just steal a block from the extent we are trying to add.
 530
 531                                  It would be nice if the blocks were close together, but it
 532                                  isn't required.
 533                 */
 534
 535                 int adsize;
 536                 short_ad *sad = NULL;
 537                 long_ad *lad = NULL;
 538                 struct allocExtDesc *aed;
 539
 540                 eloc.logicalBlockNum = start;
 541                 elen = EXT_RECORDED_ALLOCATED |
 542                         (count << sb->s_blocksize_bits);
 543
 544                 if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 545                         adsize = sizeof(short_ad);
 546                 else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 547                         adsize = sizeof(long_ad);
 548                 else
 549                 {
 550                         udf_release_data(obh);
 551                         udf_release_data(nbh);
 552                         goto error_return;
 553                 }
 554
 555                 if (nextoffset + (2 * adsize) > sb->s_blocksize)
 556                 {
 557                         char *sptr, *dptr;
 558                         int loffset;
 559
 560                         udf_release_data(obh);
 561                         obh = nbh;
 562                         obloc = nbloc;
 563                         oextoffset = nextoffset;
 564
 565                         /* Steal a block from the extent being free'd */
 566                         nbloc.logicalBlockNum = eloc.logicalBlockNum;
 567                         eloc.logicalBlockNum ++;
 568                         elen -= sb->s_blocksize;
 569
 570                         if (!(nbh = udf_tread(sb,
 571                                 udf_get_lb_pblock(sb, nbloc, 0))))
 572                         {
 573                                 udf_release_data(obh);
 574                                 goto error_return;
 575                         }
 576                         aed = (struct allocExtDesc *)(nbh->b_data);
 577                         aed->previousAllocExtLocation = cpu_to_le32(obloc.logicalBlockNum);
 578                         if (nextoffset + adsize > sb->s_blocksize)
 579                         {
 580                                 loffset = nextoffset;
 581                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 582                                 sptr = UDF_I_DATA(inode) + nextoffset -
 583                                         udf_file_entry_alloc_offset(inode) +
 584                                         UDF_I_LENEATTR(inode) - adsize;
 585                                 dptr = nbh->b_data + sizeof(struct allocExtDesc);
 586                                 memcpy(dptr, sptr, adsize);
 587                                 nextoffset = sizeof(struct allocExtDesc) + adsize;
 588                         }
 589                         else
 590                         {
 591                                 loffset = nextoffset + adsize;
 592                                 aed->lengthAllocDescs = cpu_to_le32(0);
 593                                 sptr = (obh)->b_data + nextoffset;
 594                                 nextoffset = sizeof(struct allocExtDesc);
 595
 596                                 if (obh)
 597                                 {
 598                                         aed = (struct allocExtDesc *)(obh)->b_data;
 599                                         aed->lengthAllocDescs =
 600                                                 cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 601                                 }
 602                                 else
 603                                 {
 604                                         UDF_I_LENALLOC(table) += adsize;
 605                                         mark_inode_dirty(table);
 606                                 }
 607                         }
 608                         if (UDF_SB_UDFREV(sb) >= 0x0200)
 609                                 udf_new_tag(nbh->b_data, TAG_IDENT_AED, 3, 1,
 610                                         nbloc.logicalBlockNum, sizeof(tag));
 611                         else
 612                                 udf_new_tag(nbh->b_data, TAG_IDENT_AED, 2, 1,
 613                                         nbloc.logicalBlockNum, sizeof(tag));
 614                         switch (UDF_I_ALLOCTYPE(table))
 615                         {
 616                                 case ICBTAG_FLAG_AD_SHORT:
 617                                 {
 618                                         sad = (short_ad *)sptr;
 619                                         sad->extLength = cpu_to_le32(
 620                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 621                                                 sb->s_blocksize);
 622                                         sad->extPosition = cpu_to_le32(nbloc.logicalBlockNum);
 623                                         break;
 624                                 }
 625                                 case ICBTAG_FLAG_AD_LONG:
 626                                 {
 627                                         lad = (long_ad *)sptr;
 628                                         lad->extLength = cpu_to_le32(
 629                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 630                                                 sb->s_blocksize);
 631                                         lad->extLocation = cpu_to_lelb(nbloc);
 632                                         break;
 633                                 }
 634                         }
 635                         if (obh)
 636                         {
 637                                 udf_update_tag(obh->b_data, loffset);
 638                                 mark_buffer_dirty(obh);
 639                         }
 640                         else
 641                                 mark_inode_dirty(table);
 642                 }
 643
 644                 if (elen) /* It's possible that stealing the block emptied the extent */
 645                 {
 646                         udf_write_aext(table, nbloc, &nextoffset, eloc, elen, nbh, 1);
 647
 648                         if (!nbh)
 649                         {
 650                                 UDF_I_LENALLOC(table) += adsize;
 651                                 mark_inode_dirty(table);
 652                         }
 653                         else
 654                         {
 655                                 aed = (struct allocExtDesc *)nbh->b_data;
 656                                 aed->lengthAllocDescs =
 657                                         cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 658                                 udf_update_tag(nbh->b_data, nextoffset);
 659                                 mark_buffer_dirty(nbh);
 660                         }
 661                 }
 662         }
 663
 664         udf_release_data(nbh);
 665         udf_release_data(obh);
 666
 667 error_return:
 668         sb->s_dirt = 1;
 669         up(&sbi->s_alloc_sem);
 670         return;
 671 }
 672
 673 static int udf_table_prealloc_blocks(struct super_block * sb,
 674         struct inode * inode,
 675         struct inode *table, uint16_t partition, uint32_t first_block,
 676         uint32_t block_count)
 677 {
 678         struct udf_sb_info *sbi = UDF_SB(sb);
 679         int alloc_count = 0;
 680         uint32_t extoffset, elen, adsize;
 681         kernel_lb_addr bloc, eloc;
 682         struct buffer_head *bh;
 683         int8_t etype = -1;
 684
 685         if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
 686                 return 0;
 687
 688         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 689                 adsize = sizeof(short_ad);
 690         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 691                 adsize = sizeof(long_ad);
 692         else
 693                 return 0;
 694
 695         down(&sbi->s_alloc_sem);
 696         extoffset = sizeof(struct unallocSpaceEntry);
 697         bloc = UDF_I_LOCATION(table);
 698
 699         bh = NULL;
 700         eloc.logicalBlockNum = 0xFFFFFFFF;
 701
 702         while (first_block != eloc.logicalBlockNum && (etype =
 703                 udf_next_aext(table, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
 704         {
 705                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 706                         eloc.logicalBlockNum, elen, first_block);
 707                 ; /* empty loop body */
 708         }
 709
 710         if (first_block == eloc.logicalBlockNum)
 711         {
 712                 extoffset -= adsize;
 713
 714                 alloc_count = (elen >> sb->s_blocksize_bits);
 715                 if (inode && DQUOT_PREALLOC_BLOCK(inode, alloc_count > block_count ? block_count : alloc_count))
 716                         alloc_count = 0;
 717                 else if (alloc_count > block_count)
 718                 {
 719                         alloc_count = block_count;
 720                         eloc.logicalBlockNum += alloc_count;
 721                         elen -= (alloc_count << sb->s_blocksize_bits);
 722                         udf_write_aext(table, bloc, &extoffset, eloc, (etype << 30) | elen, bh, 1);
 723                 }
 724                 else
 725                         udf_delete_aext(table, bloc, extoffset, eloc, (etype << 30) | elen, bh);
 726         }
 727         else
 728                 alloc_count = 0;
 729
 730         udf_release_data(bh);
 731
 732         if (alloc_count && UDF_SB_LVIDBH(sb))
 733         {
 734                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 735                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-alloc_count);
 736                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 737                 sb->s_dirt = 1;
 738         }
 739         up(&sbi->s_alloc_sem);
 740         return alloc_count;
 741 }
 742
 743 static int udf_table_new_block(struct super_block * sb,
 744         struct inode * inode,
 745         struct inode *table, uint16_t partition, uint32_t goal, int *err)
 746 {
 747         struct udf_sb_info *sbi = UDF_SB(sb);
 748         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 749         uint32_t newblock = 0, adsize;
 750         uint32_t extoffset, goal_extoffset, elen, goal_elen = 0;
 751         kernel_lb_addr bloc, goal_bloc, eloc, goal_eloc;
 752         struct buffer_head *bh, *goal_bh;
 753         int8_t etype;
 754
 755         *err = -ENOSPC;
 756
 757         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 758                 adsize = sizeof(short_ad);
 759         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 760                 adsize = sizeof(long_ad);
 761         else
 762                 return newblock;
 763
 764         down(&sbi->s_alloc_sem);
 765         if (goal < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
 766                 goal = 0;
 767
 768         /* We search for the closest matching block to goal. If we find a exact hit,
 769            we stop. Otherwise we keep going till we run out of extents.
 770            We store the buffer_head, bloc, and extoffset of the current closest
 771            match and use that when we are done.
 772         */
 773
 774         extoffset = sizeof(struct unallocSpaceEntry);
 775         bloc = UDF_I_LOCATION(table);
 776
 777         goal_bh = bh = NULL;
 778
 779         while (spread && (etype =
 780                 udf_next_aext(table, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
 781         {
 782                 if (goal >= eloc.logicalBlockNum)
 783                 {
 784                         if (goal < eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits))
 785                                 nspread = 0;
 786                         else
 787                                 nspread = goal - eloc.logicalBlockNum -
 788                                         (elen >> sb->s_blocksize_bits);
 789                 }
 790                 else
 791                         nspread = eloc.logicalBlockNum - goal;
 792
 793                 if (nspread < spread)
 794                 {
 795                         spread = nspread;
 796                         if (goal_bh != bh)
 797                         {
 798                                 udf_release_data(goal_bh);
 799                                 goal_bh = bh;
 800                                 atomic_inc(&goal_bh->b_count);
 801                         }
 802                         goal_bloc = bloc;
 803                         goal_extoffset = extoffset - adsize;
 804                         goal_eloc = eloc;
 805                         goal_elen = (etype << 30) | elen;
 806                 }
 807         }
 808
 809         udf_release_data(bh);
 810
 811         if (spread == 0xFFFFFFFF)
 812         {
 813                 udf_release_data(goal_bh);
 814                 up(&sbi->s_alloc_sem);
 815                 return 0;
 816         }
 817
 818         /* Only allocate blocks from the beginning of the extent.
 819            That way, we only delete (empty) extents, never have to insert an
 820            extent because of splitting */
 821         /* This works, but very poorly.... */
 822
 823         newblock = goal_eloc.logicalBlockNum;
 824         goal_eloc.logicalBlockNum ++;
 825         goal_elen -= sb->s_blocksize;
 826
 827         if (inode && DQUOT_ALLOC_BLOCK(inode, 1))
 828         {
 829                 udf_release_data(goal_bh);
 830                 up(&sbi->s_alloc_sem);
 831                 *err = -EDQUOT;
 832                 return 0;
 833         }
 834
 835         if (goal_elen)
 836                 udf_write_aext(table, goal_bloc, &goal_extoffset, goal_eloc, goal_elen, goal_bh, 1);
 837         else
 838                 udf_delete_aext(table, goal_bloc, goal_extoffset, goal_eloc, goal_elen, goal_bh);
 839         udf_release_data(goal_bh);
 840
 841         if (UDF_SB_LVIDBH(sb))
 842         {
 843                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 844                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition])-1);
 845                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 846         }
 847
 848         sb->s_dirt = 1;
 849         up(&sbi->s_alloc_sem);
 850         *err = 0;
 851         return newblock;
 852 }
 853
 854 inline void udf_free_blocks(struct super_block * sb,
 855         struct inode * inode,
 856         kernel_lb_addr bloc, uint32_t offset, uint32_t count)
 857 {
 858         uint16_t partition = bloc.partitionReferenceNum;
 859
 860         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 861         {
 862                 return udf_bitmap_free_blocks(sb, inode,
 863                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 864                         bloc, offset, count);
 865         }
 866         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 867         {
 868                 return udf_table_free_blocks(sb, inode,
 869                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 870                         bloc, offset, count);
 871         }
 872         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 873         {
 874                 return udf_bitmap_free_blocks(sb, inode,
 875                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 876                         bloc, offset, count);
 877         }
 878         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 879         {
 880                 return udf_table_free_blocks(sb, inode,
 881                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 882                         bloc, offset, count);
 883         }
 884         else
 885                 return;
 886 }
 887
 888 inline int udf_prealloc_blocks(struct super_block * sb,
 889         struct inode * inode,
 890         uint16_t partition, uint32_t first_block, uint32_t block_count)
 891 {
 892         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 893         {
 894                 return udf_bitmap_prealloc_blocks(sb, inode,
 895                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 896                         partition, first_block, block_count);
 897         }
 898         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 899         {
 900                 return udf_table_prealloc_blocks(sb, inode,
 901                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 902                         partition, first_block, block_count);
 903         }
 904         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 905         {
 906                 return udf_bitmap_prealloc_blocks(sb, inode,
 907                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 908                         partition, first_block, block_count);
 909         }
 910         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 911         {
 912                 return udf_table_prealloc_blocks(sb, inode,
 913                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 914                         partition, first_block, block_count);
 915         }
 916         else
 917                 return 0;
 918 }
 919
 920 inline int udf_new_block(struct super_block * sb,
 921         struct inode * inode,
 922         uint16_t partition, uint32_t goal, int *err)
 923 {
 924         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP)
 925         {
 926                 return udf_bitmap_new_block(sb, inode,
 927                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 928                         partition, goal, err);
 929         }
 930         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE)
 931         {
 932                 return udf_table_new_block(sb, inode,
 933                         UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 934                         partition, goal, err);
 935         }
 936         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP)
 937         {
 938                 return udf_bitmap_new_block(sb, inode,
 939                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 940                         partition, goal, err);
 941         }
 942         else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE)
 943         {
 944                 return udf_table_new_block(sb, inode,
 945                         UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 946                         partition, goal, err);
 947         }
 948         else
 949         {
 950                 *err = -EIO;
 951                 return 0;
 952         }
 953 }