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) \
  36                 find_next_one_bit(addr, size, offset)
  37
  38 #define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x)
  39 #define leNUM_to_cpup(x, y) xleNUM_to_cpup(x, y)
  40 #define xleNUM_to_cpup(x, y) (le ## x ## _to_cpup(y))
  41 #define uintBPL_t uint(BITS_PER_LONG)
  42 #define uint(x) xuint(x)
  43 #define xuint(x) __le ## x
  44
  45 static inline int find_next_one_bit(void *addr, int size, int offset)
  46 {
  47         uintBPL_t *p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG);
  48         int result = offset & ~(BITS_PER_LONG - 1);
  49         unsigned long tmp;
  50
  51         if (offset >= size)
  52                 return size;
  53         size -= result;
  54         offset &= (BITS_PER_LONG - 1);
  55         if (offset) {
  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                 tmp = leBPL_to_cpup(p++);
  67                 if (tmp)
  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,
  86                              unsigned long bitmap_nr)
  87 {
  88         struct buffer_head *bh = NULL;
  89         int retval = 0;
  90         struct kernel_lb_addr loc;
  91
  92         loc.logicalBlockNum = bitmap->s_extPosition;
  93         loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
  94
  95         bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block));
  96         if (!bh)
  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,
 105                                unsigned int block_group)
 106 {
 107         int retval = 0;
 108         int nr_groups = bitmap->s_nr_groups;
 109
 110         if (block_group >= nr_groups) {
 111                 udf_debug("block_group (%d) > nr_groups (%d)\n", block_group,
 112                           nr_groups);
 113         }
 114
 115         if (bitmap->s_block_bitmap[block_group]) {
 116                 return block_group;
 117         } else {
 118                 retval = read_block_bitmap(sb, bitmap, block_group,
 119                                            block_group);
 120                 if (retval < 0)
 121                         return retval;
 122                 return block_group;
 123         }
 124 }
 125
 126 static inline int load_block_bitmap(struct super_block *sb,
 127                                     struct udf_bitmap *bitmap,
 128                                     unsigned int block_group)
 129 {
 130         int slot;
 131
 132         slot = __load_block_bitmap(sb, bitmap, block_group);
 133
 134         if (slot < 0)
 135                 return slot;
 136
 137         if (!bitmap->s_block_bitmap[slot])
 138                 return -EIO;
 139
 140         return slot;
 141 }
 142
 143 static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
 144 {
 145         struct udf_sb_info *sbi = UDF_SB(sb);
 146         struct logicalVolIntegrityDesc *lvid;
 147
 148         if (!sbi->s_lvid_bh)
 149                 return;
 150
 151         lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 152         le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
 153         udf_updated_lvid(sb);
 154 }
 155
 156 static void udf_bitmap_free_blocks(struct super_block *sb,
 157                                    struct inode *inode,
 158                                    struct udf_bitmap *bitmap,
 159                                    struct kernel_lb_addr *bloc,
 160                                    uint32_t offset,
 161                                    uint32_t count)
 162 {
 163         struct udf_sb_info *sbi = UDF_SB(sb);
 164         struct buffer_head *bh = NULL;
 165         struct udf_part_map *partmap;
 166         unsigned long block;
 167         unsigned long block_group;
 168         unsigned long bit;
 169         unsigned long i;
 170         int bitmap_nr;
 171         unsigned long overflow;
 172
 173         mutex_lock(&sbi->s_alloc_mutex);
 174         partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 175         if (bloc->logicalBlockNum < 0 ||
 176             (bloc->logicalBlockNum + count) >
 177                 partmap->s_partition_len) {
 178                 udf_debug("%d < %d || %d + %d > %d\n",
 179                           bloc->logicalBlockNum, 0, bloc->logicalBlockNum,
 180                           count, partmap->s_partition_len);
 181                 goto error_return;
 182         }
 183
 184         block = bloc->logicalBlockNum + offset +
 185                 (sizeof(struct spaceBitmapDesc) << 3);
 186
 187         do {
 188                 overflow = 0;
 189                 block_group = block >> (sb->s_blocksize_bits + 3);
 190                 bit = block % (sb->s_blocksize << 3);
 191
 192                 /*
 193                 * Check to see if we are freeing blocks across a group boundary.
 194                 */
 195                 if (bit + count > (sb->s_blocksize << 3)) {
 196                         overflow = bit + count - (sb->s_blocksize << 3);
 197                         count -= overflow;
 198                 }
 199                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 200                 if (bitmap_nr < 0)
 201                         goto error_return;
 202
 203                 bh = bitmap->s_block_bitmap[bitmap_nr];
 204                 for (i = 0; i < count; i++) {
 205                         if (udf_set_bit(bit + i, bh->b_data)) {
 206                                 udf_debug("bit %ld already set\n", bit + i);
 207                                 udf_debug("byte=%2x\n",
 208                                         ((char *)bh->b_data)[(bit + i) >> 3]);
 209                         } else {
 210                                 if (inode)
 211                                         dquot_free_block(inode, 1);
 212                                 udf_add_free_space(sb, sbi->s_partition, 1);
 213                         }
 214                 }
 215                 mark_buffer_dirty(bh);
 216                 if (overflow) {
 217                         block += count;
 218                         count = overflow;
 219                 }
 220         } while (overflow);
 221
 222 error_return:
 223         mutex_unlock(&sbi->s_alloc_mutex);
 224 }
 225
 226 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 227                                       struct inode *inode,
 228                                       struct udf_bitmap *bitmap,
 229                                       uint16_t partition, uint32_t first_block,
 230                                       uint32_t block_count)
 231 {
 232         struct udf_sb_info *sbi = UDF_SB(sb);
 233         int alloc_count = 0;
 234         int bit, block, block_group, group_start;
 235         int nr_groups, bitmap_nr;
 236         struct buffer_head *bh;
 237         __u32 part_len;
 238
 239         mutex_lock(&sbi->s_alloc_mutex);
 240         part_len = sbi->s_partmaps[partition].s_partition_len;
 241         if (first_block >= part_len)
 242                 goto out;
 243
 244         if (first_block + block_count > part_len)
 245                 block_count = part_len - first_block;
 246
 247         do {
 248                 nr_groups = udf_compute_nr_groups(sb, partition);
 249                 block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 250                 block_group = block >> (sb->s_blocksize_bits + 3);
 251                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 252
 253                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 254                 if (bitmap_nr < 0)
 255                         goto out;
 256                 bh = bitmap->s_block_bitmap[bitmap_nr];
 257
 258                 bit = block % (sb->s_blocksize << 3);
 259
 260                 while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 261                         if (!udf_test_bit(bit, bh->b_data))
 262                                 goto out;
 263                         else if (dquot_prealloc_block(inode, 1))
 264                                 goto out;
 265                         else if (!udf_clear_bit(bit, bh->b_data)) {
 266                                 udf_debug("bit already cleared for block %d\n", bit);
 267                                 dquot_free_block(inode, 1);
 268                                 goto out;
 269                         }
 270                         block_count--;
 271                         alloc_count++;
 272                         bit++;
 273                         block++;
 274                 }
 275                 mark_buffer_dirty(bh);
 276         } while (block_count > 0);
 277
 278 out:
 279         udf_add_free_space(sb, partition, -alloc_count);
 280         mutex_unlock(&sbi->s_alloc_mutex);
 281         return alloc_count;
 282 }
 283
 284 static int udf_bitmap_new_block(struct super_block *sb,
 285                                 struct inode *inode,
 286                                 struct udf_bitmap *bitmap, uint16_t partition,
 287                                 uint32_t goal, int *err)
 288 {
 289         struct udf_sb_info *sbi = UDF_SB(sb);
 290         int newbit, bit = 0, block, block_group, group_start;
 291         int end_goal, nr_groups, bitmap_nr, i;
 292         struct buffer_head *bh = NULL;
 293         char *ptr;
 294         int newblock = 0;
 295
 296         *err = -ENOSPC;
 297         mutex_lock(&sbi->s_alloc_mutex);
 298
 299 repeat:
 300         if (goal >= sbi->s_partmaps[partition].s_partition_len)
 301                 goal = 0;
 302
 303         nr_groups = bitmap->s_nr_groups;
 304         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 305         block_group = block >> (sb->s_blocksize_bits + 3);
 306         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 307
 308         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 309         if (bitmap_nr < 0)
 310                 goto error_return;
 311         bh = bitmap->s_block_bitmap[bitmap_nr];
 312         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 313                       sb->s_blocksize - group_start);
 314
 315         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 316                 bit = block % (sb->s_blocksize << 3);
 317                 if (udf_test_bit(bit, bh->b_data))
 318                         goto got_block;
 319
 320                 end_goal = (bit + 63) & ~63;
 321                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 322                 if (bit < end_goal)
 323                         goto got_block;
 324
 325                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
 326                               sb->s_blocksize - ((bit + 7) >> 3));
 327                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 328                 if (newbit < sb->s_blocksize << 3) {
 329                         bit = newbit;
 330                         goto search_back;
 331                 }
 332
 333                 newbit = udf_find_next_one_bit(bh->b_data,
 334                                                sb->s_blocksize << 3, bit);
 335                 if (newbit < sb->s_blocksize << 3) {
 336                         bit = newbit;
 337                         goto got_block;
 338                 }
 339         }
 340
 341         for (i = 0; i < (nr_groups * 2); i++) {
 342                 block_group++;
 343                 if (block_group >= nr_groups)
 344                         block_group = 0;
 345                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 346
 347                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 348                 if (bitmap_nr < 0)
 349                         goto error_return;
 350                 bh = bitmap->s_block_bitmap[bitmap_nr];
 351                 if (i < nr_groups) {
 352                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 353                                       sb->s_blocksize - group_start);
 354                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 355                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 356                                 break;
 357                         }
 358                 } else {
 359                         bit = udf_find_next_one_bit((char *)bh->b_data,
 360                                                     sb->s_blocksize << 3,
 361                                                     group_start << 3);
 362                         if (bit < sb->s_blocksize << 3)
 363                                 break;
 364                 }
 365         }
 366         if (i >= (nr_groups * 2)) {
 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,
 374                                             group_start << 3);
 375         if (bit >= sb->s_blocksize << 3) {
 376                 mutex_unlock(&sbi->s_alloc_mutex);
 377                 return 0;
 378         }
 379
 380 search_back:
 381         i = 0;
 382         while (i < 7 && bit > (group_start << 3) &&
 383                udf_test_bit(bit - 1, bh->b_data)) {
 384                 ++i;
 385                 --bit;
 386         }
 387
 388 got_block:
 389
 390         /*
 391          * Check quota for allocation of this block.
 392          */
 393         if (inode) {
 394                 int ret = dquot_alloc_block(inode, 1);
 395
 396                 if (ret) {
 397                         mutex_unlock(&sbi->s_alloc_mutex);
 398                         *err = ret;
 399                         return 0;
 400                 }
 401         }
 402
 403         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 404                 (sizeof(struct spaceBitmapDesc) << 3);
 405
 406         if (!udf_clear_bit(bit, bh->b_data)) {
 407                 udf_debug("bit already cleared for block %d\n", bit);
 408                 goto repeat;
 409         }
 410
 411         mark_buffer_dirty(bh);
 412
 413         udf_add_free_space(sb, partition, -1);
 414         mutex_unlock(&sbi->s_alloc_mutex);
 415         *err = 0;
 416         return newblock;
 417
 418 error_return:
 419         *err = -EIO;
 420         mutex_unlock(&sbi->s_alloc_mutex);
 421         return 0;
 422 }
 423
 424 static void udf_table_free_blocks(struct super_block *sb,
 425                                   struct inode *inode,
 426                                   struct inode *table,
 427                                   struct kernel_lb_addr *bloc,
 428                                   uint32_t offset,
 429                                   uint32_t count)
 430 {
 431         struct udf_sb_info *sbi = UDF_SB(sb);
 432         struct udf_part_map *partmap;
 433         uint32_t start, end;
 434         uint32_t elen;
 435         struct kernel_lb_addr eloc;
 436         struct extent_position oepos, epos;
 437         int8_t etype;
 438         int i;
 439         struct udf_inode_info *iinfo;
 440
 441         mutex_lock(&sbi->s_alloc_mutex);
 442         partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 443         if (bloc->logicalBlockNum < 0 ||
 444             (bloc->logicalBlockNum + count) >
 445                 partmap->s_partition_len) {
 446                 udf_debug("%d < %d || %d + %d > %d\n",
 447                           bloc->logicalBlockNum, 0, bloc->logicalBlockNum, count,
 448                           partmap->s_partition_len);
 449                 goto error_return;
 450         }
 451
 452         iinfo = UDF_I(table);
 453         /* We do this up front - There are some error conditions that
 454            could occure, but.. oh well */
 455         if (inode)
 456                 dquot_free_block(inode, count);
 457         udf_add_free_space(sb, sbi->s_partition, count);
 458
 459         start = bloc->logicalBlockNum + offset;
 460         end = bloc->logicalBlockNum + offset + count - 1;
 461
 462         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 463         elen = 0;
 464         epos.block = oepos.block = iinfo->i_location;
 465         epos.bh = oepos.bh = NULL;
 466
 467         while (count &&
 468                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 469                 if (((eloc.logicalBlockNum +
 470                         (elen >> sb->s_blocksize_bits)) == start)) {
 471                         if ((0x3FFFFFFF - elen) <
 472                                         (count << sb->s_blocksize_bits)) {
 473                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 474                                                         sb->s_blocksize_bits);
 475                                 count -= tmp;
 476                                 start += tmp;
 477                                 elen = (etype << 30) |
 478                                         (0x40000000 - sb->s_blocksize);
 479                         } else {
 480                                 elen = (etype << 30) |
 481                                         (elen +
 482                                         (count << sb->s_blocksize_bits));
 483                                 start += count;
 484                                 count = 0;
 485                         }
 486                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 487                 } else if (eloc.logicalBlockNum == (end + 1)) {
 488                         if ((0x3FFFFFFF - elen) <
 489                                         (count << sb->s_blocksize_bits)) {
 490                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 491                                                 sb->s_blocksize_bits);
 492                                 count -= tmp;
 493                                 end -= tmp;
 494                                 eloc.logicalBlockNum -= tmp;
 495                                 elen = (etype << 30) |
 496                                         (0x40000000 - sb->s_blocksize);
 497                         } else {
 498                                 eloc.logicalBlockNum = start;
 499                                 elen = (etype << 30) |
 500                                         (elen +
 501                                         (count << sb->s_blocksize_bits));
 502                                 end -= count;
 503                                 count = 0;
 504                         }
 505                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 506                 }
 507
 508                 if (epos.bh != oepos.bh) {
 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                 } else {
 516                         oepos.offset = epos.offset;
 517                 }
 518         }
 519
 520         if (count) {
 521                 /*
 522                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
 523                  * allocate a new block, and since we hold the super block
 524                  * lock already 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                 struct short_ad *sad = NULL;
 536                 struct 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 (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 544                         adsize = sizeof(struct short_ad);
 545                 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 546                         adsize = sizeof(struct long_ad);
 547                 else {
 548                         brelse(oepos.bh);
 549                         brelse(epos.bh);
 550                         goto error_return;
 551                 }
 552
 553                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 554                         unsigned char *sptr, *dptr;
 555                         int loffset;
 556
 557                         brelse(oepos.bh);
 558                         oepos = epos;
 559
 560                         /* Steal a block from the extent being free'd */
 561                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 562                         eloc.logicalBlockNum++;
 563                         elen -= sb->s_blocksize;
 564
 565                         epos.bh = udf_tread(sb,
 566                                         udf_get_lb_pblock(sb, &epos.block, 0));
 567                         if (!epos.bh) {
 568                                 brelse(oepos.bh);
 569                                 goto error_return;
 570                         }
 571                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 572                         aed->previousAllocExtLocation =
 573                                 cpu_to_le32(oepos.block.logicalBlockNum);
 574                         if (epos.offset + adsize > sb->s_blocksize) {
 575                                 loffset = epos.offset;
 576                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 577                                 sptr = iinfo->i_ext.i_data + epos.offset
 578                                                                 - adsize;
 579                                 dptr = epos.bh->b_data +
 580                                         sizeof(struct allocExtDesc);
 581                                 memcpy(dptr, sptr, adsize);
 582                                 epos.offset = sizeof(struct allocExtDesc) +
 583                                                 adsize;
 584                         } else {
 585                                 loffset = epos.offset + adsize;
 586                                 aed->lengthAllocDescs = cpu_to_le32(0);
 587                                 if (oepos.bh) {
 588                                         sptr = oepos.bh->b_data + epos.offset;
 589                                         aed = (struct allocExtDesc *)
 590                                                 oepos.bh->b_data;
 591                                         le32_add_cpu(&aed->lengthAllocDescs,
 592                                                         adsize);
 593                                 } else {
 594                                         sptr = iinfo->i_ext.i_data +
 595                                                                 epos.offset;
 596                                         iinfo->i_lenAlloc += adsize;
 597                                         mark_inode_dirty(table);
 598                                 }
 599                                 epos.offset = sizeof(struct allocExtDesc);
 600                         }
 601                         if (sbi->s_udfrev >= 0x0200)
 602                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 603                                             3, 1, epos.block.logicalBlockNum,
 604                                             sizeof(struct tag));
 605                         else
 606                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 607                                             2, 1, epos.block.logicalBlockNum,
 608                                             sizeof(struct tag));
 609
 610                         switch (iinfo->i_alloc_type) {
 611                         case ICBTAG_FLAG_AD_SHORT:
 612                                 sad = (struct short_ad *)sptr;
 613                                 sad->extLength = cpu_to_le32(
 614                                         EXT_NEXT_EXTENT_ALLOCDECS |
 615                                         sb->s_blocksize);
 616                                 sad->extPosition =
 617                                         cpu_to_le32(epos.block.logicalBlockNum);
 618                                 break;
 619                         case ICBTAG_FLAG_AD_LONG:
 620                                 lad = (struct long_ad *)sptr;
 621                                 lad->extLength = cpu_to_le32(
 622                                         EXT_NEXT_EXTENT_ALLOCDECS |
 623                                         sb->s_blocksize);
 624                                 lad->extLocation =
 625                                         cpu_to_lelb(epos.block);
 626                                 break;
 627                         }
 628                         if (oepos.bh) {
 629                                 udf_update_tag(oepos.bh->b_data, loffset);
 630                                 mark_buffer_dirty(oepos.bh);
 631                         } else {
 632                                 mark_inode_dirty(table);
 633                         }
 634                 }
 635
 636                 /* It's possible that stealing the block emptied the extent */
 637                 if (elen) {
 638                         udf_write_aext(table, &epos, &eloc, elen, 1);
 639
 640                         if (!epos.bh) {
 641                                 iinfo->i_lenAlloc += adsize;
 642                                 mark_inode_dirty(table);
 643                         } else {
 644                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 645                                 le32_add_cpu(&aed->lengthAllocDescs, adsize);
 646                                 udf_update_tag(epos.bh->b_data, epos.offset);
 647                                 mark_buffer_dirty(epos.bh);
 648                         }
 649                 }
 650         }
 651
 652         brelse(epos.bh);
 653         brelse(oepos.bh);
 654
 655 error_return:
 656         mutex_unlock(&sbi->s_alloc_mutex);
 657         return;
 658 }
 659
 660 static int udf_table_prealloc_blocks(struct super_block *sb,
 661                                      struct inode *inode,
 662                                      struct inode *table, uint16_t partition,
 663                                      uint32_t first_block, uint32_t block_count)
 664 {
 665         struct udf_sb_info *sbi = UDF_SB(sb);
 666         int alloc_count = 0;
 667         uint32_t elen, adsize;
 668         struct kernel_lb_addr eloc;
 669         struct extent_position epos;
 670         int8_t etype = -1;
 671         struct udf_inode_info *iinfo;
 672
 673         if (first_block >= sbi->s_partmaps[partition].s_partition_len)
 674                 return 0;
 675
 676         iinfo = UDF_I(table);
 677         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 678                 adsize = sizeof(struct short_ad);
 679         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 680                 adsize = sizeof(struct long_ad);
 681         else
 682                 return 0;
 683
 684         mutex_lock(&sbi->s_alloc_mutex);
 685         epos.offset = sizeof(struct unallocSpaceEntry);
 686         epos.block = iinfo->i_location;
 687         epos.bh = NULL;
 688         eloc.logicalBlockNum = 0xFFFFFFFF;
 689
 690         while (first_block != eloc.logicalBlockNum &&
 691                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 692                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 693                           eloc.logicalBlockNum, elen, first_block);
 694                 ; /* empty loop body */
 695         }
 696
 697         if (first_block == eloc.logicalBlockNum) {
 698                 epos.offset -= adsize;
 699
 700                 alloc_count = (elen >> sb->s_blocksize_bits);
 701                 if (inode && dquot_prealloc_block(inode,
 702                         alloc_count > block_count ? block_count : alloc_count))
 703                         alloc_count = 0;
 704                 else if (alloc_count > block_count) {
 705                         alloc_count = block_count;
 706                         eloc.logicalBlockNum += alloc_count;
 707                         elen -= (alloc_count << sb->s_blocksize_bits);
 708                         udf_write_aext(table, &epos, &eloc,
 709                                         (etype << 30) | elen, 1);
 710                 } else
 711                         udf_delete_aext(table, epos, eloc,
 712                                         (etype << 30) | elen);
 713         } else {
 714                 alloc_count = 0;
 715         }
 716
 717         brelse(epos.bh);
 718
 719         if (alloc_count)
 720                 udf_add_free_space(sb, partition, -alloc_count);
 721         mutex_unlock(&sbi->s_alloc_mutex);
 722         return alloc_count;
 723 }
 724
 725 static int udf_table_new_block(struct super_block *sb,
 726                                struct inode *inode,
 727                                struct inode *table, uint16_t partition,
 728                                uint32_t goal, int *err)
 729 {
 730         struct udf_sb_info *sbi = UDF_SB(sb);
 731         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 732         uint32_t newblock = 0, adsize;
 733         uint32_t elen, goal_elen = 0;
 734         struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 735         struct extent_position epos, goal_epos;
 736         int8_t etype;
 737         struct udf_inode_info *iinfo = UDF_I(table);
 738
 739         *err = -ENOSPC;
 740
 741         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 742                 adsize = sizeof(struct short_ad);
 743         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 744                 adsize = sizeof(struct long_ad);
 745         else
 746                 return newblock;
 747
 748         mutex_lock(&sbi->s_alloc_mutex);
 749         if (goal >= sbi->s_partmaps[partition].s_partition_len)
 750                 goal = 0;
 751
 752         /* We search for the closest matching block to goal. If we find
 753            a exact hit, we stop. Otherwise we keep going till we run out
 754            of extents. We store the buffer_head, bloc, and extoffset
 755            of the current closest match and use that when we are done.
 756          */
 757         epos.offset = sizeof(struct unallocSpaceEntry);
 758         epos.block = iinfo->i_location;
 759         epos.bh = goal_epos.bh = NULL;
 760
 761         while (spread &&
 762                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 763                 if (goal >= eloc.logicalBlockNum) {
 764                         if (goal < eloc.logicalBlockNum +
 765                                         (elen >> sb->s_blocksize_bits))
 766                                 nspread = 0;
 767                         else
 768                                 nspread = goal - eloc.logicalBlockNum -
 769                                         (elen >> sb->s_blocksize_bits);
 770                 } else {
 771                         nspread = eloc.logicalBlockNum - goal;
 772                 }
 773
 774                 if (nspread < spread) {
 775                         spread = nspread;
 776                         if (goal_epos.bh != epos.bh) {
 777                                 brelse(goal_epos.bh);
 778                                 goal_epos.bh = epos.bh;
 779                                 get_bh(goal_epos.bh);
 780                         }
 781                         goal_epos.block = epos.block;
 782                         goal_epos.offset = epos.offset - adsize;
 783                         goal_eloc = eloc;
 784                         goal_elen = (etype << 30) | elen;
 785                 }
 786         }
 787
 788         brelse(epos.bh);
 789
 790         if (spread == 0xFFFFFFFF) {
 791                 brelse(goal_epos.bh);
 792                 mutex_unlock(&sbi->s_alloc_mutex);
 793                 return 0;
 794         }
 795
 796         /* Only allocate blocks from the beginning of the extent.
 797            That way, we only delete (empty) extents, never have to insert an
 798            extent because of splitting */
 799         /* This works, but very poorly.... */
 800
 801         newblock = goal_eloc.logicalBlockNum;
 802         goal_eloc.logicalBlockNum++;
 803         goal_elen -= sb->s_blocksize;
 804         if (inode) {
 805                 *err = dquot_alloc_block(inode, 1);
 806                 if (*err) {
 807                         brelse(goal_epos.bh);
 808                         mutex_unlock(&sbi->s_alloc_mutex);
 809                         return 0;
 810                 }
 811         }
 812
 813         if (goal_elen)
 814                 udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
 815         else
 816                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 817         brelse(goal_epos.bh);
 818
 819         udf_add_free_space(sb, partition, -1);
 820
 821         mutex_unlock(&sbi->s_alloc_mutex);
 822         *err = 0;
 823         return newblock;
 824 }
 825
 826 void udf_free_blocks(struct super_block *sb, struct inode *inode,
 827                      struct kernel_lb_addr *bloc, uint32_t offset,
 828                      uint32_t count)
 829 {
 830         uint16_t partition = bloc->partitionReferenceNum;
 831         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 832
 833         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 834                 udf_bitmap_free_blocks(sb, inode, map->s_uspace.s_bitmap,
 835                                        bloc, offset, count);
 836         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 837                 udf_table_free_blocks(sb, inode, map->s_uspace.s_table,
 838                                       bloc, offset, count);
 839         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 840                 udf_bitmap_free_blocks(sb, inode, map->s_fspace.s_bitmap,
 841                                        bloc, offset, count);
 842         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 843                 udf_table_free_blocks(sb, inode, map->s_fspace.s_table,
 844                                       bloc, offset, count);
 845         }
 846 }
 847
 848 inline int udf_prealloc_blocks(struct super_block *sb,
 849                                struct inode *inode,
 850                                uint16_t partition, uint32_t first_block,
 851                                uint32_t block_count)
 852 {
 853         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 854
 855         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 856                 return udf_bitmap_prealloc_blocks(sb, inode,
 857                                                   map->s_uspace.s_bitmap,
 858                                                   partition, first_block,
 859                                                   block_count);
 860         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 861                 return udf_table_prealloc_blocks(sb, inode,
 862                                                  map->s_uspace.s_table,
 863                                                  partition, first_block,
 864                                                  block_count);
 865         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 866                 return udf_bitmap_prealloc_blocks(sb, inode,
 867                                                   map->s_fspace.s_bitmap,
 868                                                   partition, first_block,
 869                                                   block_count);
 870         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 871                 return udf_table_prealloc_blocks(sb, inode,
 872                                                  map->s_fspace.s_table,
 873                                                  partition, first_block,
 874                                                  block_count);
 875         else
 876                 return 0;
 877 }
 878
 879 inline int udf_new_block(struct super_block *sb,
 880                          struct inode *inode,
 881                          uint16_t partition, uint32_t goal, int *err)
 882 {
 883         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 884
 885         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 886                 return udf_bitmap_new_block(sb, inode,
 887                                            map->s_uspace.s_bitmap,
 888                                            partition, goal, err);
 889         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 890                 return udf_table_new_block(sb, inode,
 891                                            map->s_uspace.s_table,
 892                                            partition, goal, err);
 893         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 894                 return udf_bitmap_new_block(sb, inode,
 895                                             map->s_fspace.s_bitmap,
 896                                             partition, goal, err);
 897         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 898                 return udf_table_new_block(sb, inode,
 899                                            map->s_fspace.s_table,
 900                                            partition, goal, err);
 901         else {
 902                 *err = -EIO;
 903                 return 0;
 904         }
 905 }