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         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 bool udf_add_free_space(struct udf_sb_info *sbi,
 144                                 u16 partition, u32 cnt)
 145 {
 146         struct logicalVolIntegrityDesc *lvid;
 147
 148         if (sbi->s_lvid_bh)
 149                 return false;
 150
 151         lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 152         lvid->freeSpaceTable[partition] = cpu_to_le32(le32_to_cpu(
 153                                         lvid->freeSpaceTable[partition]) + cnt);
 154         return true;
 155 }
 156
 157 static void udf_bitmap_free_blocks(struct super_block *sb,
 158                                    struct inode *inode,
 159                                    struct udf_bitmap *bitmap,
 160                                    kernel_lb_addr bloc, uint32_t offset,
 161                                    uint32_t count)
 162 {
 163         struct udf_sb_info *sbi = UDF_SB(sb);
 164         struct buffer_head *bh = NULL;
 165         unsigned long block;
 166         unsigned long block_group;
 167         unsigned long bit;
 168         unsigned long i;
 169         int bitmap_nr;
 170         unsigned long overflow;
 171
 172         mutex_lock(&sbi->s_alloc_mutex);
 173         if (bloc.logicalBlockNum < 0 ||
 174             (bloc.logicalBlockNum + count) >
 175                 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
 176                 udf_debug("%d < %d || %d + %d > %d\n",
 177                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 178                           sbi->s_partmaps[bloc.partitionReferenceNum].
 179                                                         s_partition_len);
 180                 goto error_return;
 181         }
 182
 183         block = bloc.logicalBlockNum + offset +
 184                 (sizeof(struct spaceBitmapDesc) << 3);
 185
 186         do {
 187                 overflow = 0;
 188                 block_group = block >> (sb->s_blocksize_bits + 3);
 189                 bit = block % (sb->s_blocksize << 3);
 190
 191                 /*
 192                 * Check to see if we are freeing blocks across a group boundary.
 193                 */
 194                 if (bit + count > (sb->s_blocksize << 3)) {
 195                         overflow = bit + count - (sb->s_blocksize << 3);
 196                         count -= overflow;
 197                 }
 198                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 199                 if (bitmap_nr < 0)
 200                         goto error_return;
 201
 202                 bh = bitmap->s_block_bitmap[bitmap_nr];
 203                 for (i = 0; i < count; i++) {
 204                         if (udf_set_bit(bit + i, bh->b_data)) {
 205                                 udf_debug("bit %ld already set\n", bit + i);
 206                                 udf_debug("byte=%2x\n",
 207                                         ((char *)bh->b_data)[(bit + i) >> 3]);
 208                         } else {
 209                                 if (inode)
 210                                         DQUOT_FREE_BLOCK(inode, 1);
 211                                 udf_add_free_space(sbi, sbi->s_partition, 1);
 212                         }
 213                 }
 214                 mark_buffer_dirty(bh);
 215                 if (overflow) {
 216                         block += count;
 217                         count = overflow;
 218                 }
 219         } while (overflow);
 220
 221 error_return:
 222         sb->s_dirt = 1;
 223         if (sbi->s_lvid_bh)
 224                 mark_buffer_dirty(sbi->s_lvid_bh);
 225         mutex_unlock(&sbi->s_alloc_mutex);
 226 }
 227
 228 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 229                                       struct inode *inode,
 230                                       struct udf_bitmap *bitmap,
 231                                       uint16_t partition, uint32_t first_block,
 232                                       uint32_t block_count)
 233 {
 234         struct udf_sb_info *sbi = UDF_SB(sb);
 235         int alloc_count = 0;
 236         int bit, block, block_group, group_start;
 237         int nr_groups, bitmap_nr;
 238         struct buffer_head *bh;
 239         __u32 part_len;
 240
 241         mutex_lock(&sbi->s_alloc_mutex);
 242         part_len = sbi->s_partmaps[partition].s_partition_len;
 243         if (first_block < 0 || first_block >= part_len)
 244                 goto out;
 245
 246         if (first_block + block_count > part_len)
 247                 block_count = part_len - first_block;
 248
 249         do {
 250                 nr_groups = udf_compute_nr_groups(sb, partition);
 251                 block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 252                 block_group = block >> (sb->s_blocksize_bits + 3);
 253                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 254
 255                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 256                 if (bitmap_nr < 0)
 257                         goto out;
 258                 bh = bitmap->s_block_bitmap[bitmap_nr];
 259
 260                 bit = block % (sb->s_blocksize << 3);
 261
 262                 while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 263                         if (!udf_test_bit(bit, bh->b_data))
 264                                 goto out;
 265                         else if (DQUOT_PREALLOC_BLOCK(inode, 1))
 266                                 goto out;
 267                         else if (!udf_clear_bit(bit, bh->b_data)) {
 268                                 udf_debug("bit already cleared for block %d\n", bit);
 269                                 DQUOT_FREE_BLOCK(inode, 1);
 270                                 goto out;
 271                         }
 272                         block_count--;
 273                         alloc_count++;
 274                         bit++;
 275                         block++;
 276                 }
 277                 mark_buffer_dirty(bh);
 278         } while (block_count > 0);
 279
 280 out:
 281         if (udf_add_free_space(sbi, partition, -alloc_count))
 282                 mark_buffer_dirty(sbi->s_lvid_bh);
 283         sb->s_dirt = 1;
 284         mutex_unlock(&sbi->s_alloc_mutex);
 285         return alloc_count;
 286 }
 287
 288 static int udf_bitmap_new_block(struct super_block *sb,
 289                                 struct inode *inode,
 290                                 struct udf_bitmap *bitmap, uint16_t partition,
 291                                 uint32_t goal, int *err)
 292 {
 293         struct udf_sb_info *sbi = UDF_SB(sb);
 294         int newbit, bit = 0, block, block_group, group_start;
 295         int end_goal, nr_groups, bitmap_nr, i;
 296         struct buffer_head *bh = NULL;
 297         char *ptr;
 298         int newblock = 0;
 299
 300         *err = -ENOSPC;
 301         mutex_lock(&sbi->s_alloc_mutex);
 302
 303 repeat:
 304         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 305                 goal = 0;
 306
 307         nr_groups = bitmap->s_nr_groups;
 308         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 309         block_group = block >> (sb->s_blocksize_bits + 3);
 310         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 311
 312         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 313         if (bitmap_nr < 0)
 314                 goto error_return;
 315         bh = bitmap->s_block_bitmap[bitmap_nr];
 316         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 317                       sb->s_blocksize - group_start);
 318
 319         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 320                 bit = block % (sb->s_blocksize << 3);
 321                 if (udf_test_bit(bit, bh->b_data))
 322                         goto got_block;
 323
 324                 end_goal = (bit + 63) & ~63;
 325                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 326                 if (bit < end_goal)
 327                         goto got_block;
 328
 329                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
 330                               sb->s_blocksize - ((bit + 7) >> 3));
 331                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 332                 if (newbit < sb->s_blocksize << 3) {
 333                         bit = newbit;
 334                         goto search_back;
 335                 }
 336
 337                 newbit = udf_find_next_one_bit(bh->b_data,
 338                                                sb->s_blocksize << 3, bit);
 339                 if (newbit < sb->s_blocksize << 3) {
 340                         bit = newbit;
 341                         goto got_block;
 342                 }
 343         }
 344
 345         for (i = 0; i < (nr_groups * 2); i++) {
 346                 block_group++;
 347                 if (block_group >= nr_groups)
 348                         block_group = 0;
 349                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 350
 351                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 352                 if (bitmap_nr < 0)
 353                         goto error_return;
 354                 bh = bitmap->s_block_bitmap[bitmap_nr];
 355                 if (i < nr_groups) {
 356                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 357                                       sb->s_blocksize - group_start);
 358                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 359                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 360                                 break;
 361                         }
 362                 } else {
 363                         bit = udf_find_next_one_bit((char *)bh->b_data,
 364                                                     sb->s_blocksize << 3,
 365                                                     group_start << 3);
 366                         if (bit < sb->s_blocksize << 3)
 367                                 break;
 368                 }
 369         }
 370         if (i >= (nr_groups * 2)) {
 371                 mutex_unlock(&sbi->s_alloc_mutex);
 372                 return newblock;
 373         }
 374         if (bit < sb->s_blocksize << 3)
 375                 goto search_back;
 376         else
 377                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
 378                                             group_start << 3);
 379         if (bit >= sb->s_blocksize << 3) {
 380                 mutex_unlock(&sbi->s_alloc_mutex);
 381                 return 0;
 382         }
 383
 384 search_back:
 385         i = 0;
 386         while (i < 7 && bit > (group_start << 3) &&
 387                udf_test_bit(bit - 1, bh->b_data)) {
 388                 ++i;
 389                 --bit;
 390         }
 391
 392 got_block:
 393
 394         /*
 395          * Check quota for allocation of this block.
 396          */
 397         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 398                 mutex_unlock(&sbi->s_alloc_mutex);
 399                 *err = -EDQUOT;
 400                 return 0;
 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         if (udf_add_free_space(sbi, partition, -1))
 414                 mark_buffer_dirty(sbi->s_lvid_bh);
 415         sb->s_dirt = 1;
 416         mutex_unlock(&sbi->s_alloc_mutex);
 417         *err = 0;
 418         return newblock;
 419
 420 error_return:
 421         *err = -EIO;
 422         mutex_unlock(&sbi->s_alloc_mutex);
 423         return 0;
 424 }
 425
 426 static void udf_table_free_blocks(struct super_block *sb,
 427                                   struct inode *inode,
 428                                   struct inode *table,
 429                                   kernel_lb_addr bloc, uint32_t offset,
 430                                   uint32_t count)
 431 {
 432         struct udf_sb_info *sbi = UDF_SB(sb);
 433         uint32_t start, end;
 434         uint32_t elen;
 435         kernel_lb_addr eloc;
 436         struct extent_position oepos, epos;
 437         int8_t etype;
 438         int i;
 439
 440         mutex_lock(&sbi->s_alloc_mutex);
 441         if (bloc.logicalBlockNum < 0 ||
 442             (bloc.logicalBlockNum + count) >
 443                 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
 444                 udf_debug("%d < %d || %d + %d > %d\n",
 445                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 446                           sbi->s_partmaps[bloc.partitionReferenceNum].
 447                                                         s_partition_len);
 448                 goto error_return;
 449         }
 450
 451         /* We do this up front - There are some error conditions that
 452            could occure, but.. oh well */
 453         if (inode)
 454                 DQUOT_FREE_BLOCK(inode, count);
 455         if (udf_add_free_space(sbi, sbi->s_partition, count))
 456                 mark_buffer_dirty(sbi->s_lvid_bh);
 457
 458         start = bloc.logicalBlockNum + offset;
 459         end = bloc.logicalBlockNum + offset + count - 1;
 460
 461         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 462         elen = 0;
 463         epos.block = oepos.block = UDF_I_LOCATION(table);
 464         epos.bh = oepos.bh = NULL;
 465
 466         while (count &&
 467                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 468                 if (((eloc.logicalBlockNum +
 469                         (elen >> sb->s_blocksize_bits)) == start)) {
 470                         if ((0x3FFFFFFF - elen) <
 471                                         (count << sb->s_blocksize_bits)) {
 472                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 473                                                         sb->s_blocksize_bits);
 474                                 count -= tmp;
 475                                 start += tmp;
 476                                 elen = (etype << 30) |
 477                                         (0x40000000 - sb->s_blocksize);
 478                         } else {
 479                                 elen = (etype << 30) |
 480                                         (elen +
 481                                         (count << sb->s_blocksize_bits));
 482                                 start += count;
 483                                 count = 0;
 484                         }
 485                         udf_write_aext(table, &oepos, eloc, elen, 1);
 486                 } else if (eloc.logicalBlockNum == (end + 1)) {
 487                         if ((0x3FFFFFFF - elen) <
 488                                         (count << sb->s_blocksize_bits)) {
 489                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 490                                                 sb->s_blocksize_bits);
 491                                 count -= tmp;
 492                                 end -= tmp;
 493                                 eloc.logicalBlockNum -= tmp;
 494                                 elen = (etype << 30) |
 495                                         (0x40000000 - sb->s_blocksize);
 496                         } else {
 497                                 eloc.logicalBlockNum = start;
 498                                 elen = (etype << 30) |
 499                                         (elen +
 500                                         (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                         i = -1;
 509                         oepos.block = epos.block;
 510                         brelse(oepos.bh);
 511                         get_bh(epos.bh);
 512                         oepos.bh = epos.bh;
 513                         oepos.offset = 0;
 514                 } else {
 515                         oepos.offset = epos.offset;
 516                 }
 517         }
 518
 519         if (count) {
 520                 /*
 521                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
 522                  * allocate a new block, and since we hold the super block
 523                  * lock already very bad things would happen :)
 524                  *
 525                  * We copy the behavior of udf_add_aext, but instead of
 526                  * trying to allocate a new block close to the existing one,
 527                  * we just steal a block from the extent we are trying to add.
 528                  *
 529                  * It would be nice if the blocks were close together, but it
 530                  * isn't required.
 531                  */
 532
 533                 int adsize;
 534                 short_ad *sad = NULL;
 535                 long_ad *lad = NULL;
 536                 struct allocExtDesc *aed;
 537
 538                 eloc.logicalBlockNum = start;
 539                 elen = EXT_RECORDED_ALLOCATED |
 540                         (count << sb->s_blocksize_bits);
 541
 542                 if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT) {
 543                         adsize = sizeof(short_ad);
 544                 } else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG) {
 545                         adsize = sizeof(long_ad);
 546                 } else {
 547                         brelse(oepos.bh);
 548                         brelse(epos.bh);
 549                         goto error_return;
 550                 }
 551
 552                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 553                         char *sptr, *dptr;
 554                         int loffset;
 555
 556                         brelse(oepos.bh);
 557                         oepos = epos;
 558
 559                         /* Steal a block from the extent being free'd */
 560                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 561                         eloc.logicalBlockNum++;
 562                         elen -= sb->s_blocksize;
 563
 564                         epos.bh = udf_tread(sb,
 565                                         udf_get_lb_pblock(sb, epos.block, 0));
 566                         if (!epos.bh) {
 567                                 brelse(oepos.bh);
 568                                 goto error_return;
 569                         }
 570                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 571                         aed->previousAllocExtLocation =
 572                                 cpu_to_le32(oepos.block.logicalBlockNum);
 573                         if (epos.offset + adsize > sb->s_blocksize) {
 574                                 loffset = epos.offset;
 575                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 576                                 sptr = UDF_I_DATA(table) + epos.offset - adsize;
 577                                 dptr = epos.bh->b_data +
 578                                         sizeof(struct allocExtDesc);
 579                                 memcpy(dptr, sptr, adsize);
 580                                 epos.offset = sizeof(struct allocExtDesc) +
 581                                                 adsize;
 582                         } else {
 583                                 loffset = epos.offset + adsize;
 584                                 aed->lengthAllocDescs = cpu_to_le32(0);
 585                                 if (oepos.bh) {
 586                                         sptr = oepos.bh->b_data + epos.offset;
 587                                         aed = (struct allocExtDesc *)
 588                                                 oepos.bh->b_data;
 589                                         aed->lengthAllocDescs =
 590                                                 cpu_to_le32(le32_to_cpu(
 591                                                         aed->lengthAllocDescs) +
 592                                                                 adsize);
 593                                 } else {
 594                                         sptr = UDF_I_DATA(table) + epos.offset;
 595                                         UDF_I_LENALLOC(table) += adsize;
 596                                         mark_inode_dirty(table);
 597                                 }
 598                                 epos.offset = sizeof(struct allocExtDesc);
 599                         }
 600                         if (sbi->s_udfrev >= 0x0200)
 601                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 602                                             3, 1, epos.block.logicalBlockNum,
 603                                             sizeof(tag));
 604                         else
 605                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 606                                             2, 1, epos.block.logicalBlockNum,
 607                                             sizeof(tag));
 608
 609                         switch (UDF_I_ALLOCTYPE(table)) {
 610                         case ICBTAG_FLAG_AD_SHORT:
 611                                 sad = (short_ad *)sptr;
 612                                 sad->extLength = cpu_to_le32(
 613                                         EXT_NEXT_EXTENT_ALLOCDECS |
 614                                         sb->s_blocksize);
 615                                 sad->extPosition =
 616                                         cpu_to_le32(epos.block.logicalBlockNum);
 617                                 break;
 618                         case ICBTAG_FLAG_AD_LONG:
 619                                 lad = (long_ad *)sptr;
 620                                 lad->extLength = cpu_to_le32(
 621                                         EXT_NEXT_EXTENT_ALLOCDECS |
 622                                         sb->s_blocksize);
 623                                 lad->extLocation =
 624                                         cpu_to_lelb(epos.block);
 625                                 break;
 626                         }
 627                         if (oepos.bh) {
 628                                 udf_update_tag(oepos.bh->b_data, loffset);
 629                                 mark_buffer_dirty(oepos.bh);
 630                         } else {
 631                                 mark_inode_dirty(table);
 632                         }
 633                 }
 634
 635                 /* It's possible that stealing the block emptied the extent */
 636                 if (elen) {
 637                         udf_write_aext(table, &epos, eloc, elen, 1);
 638
 639                         if (!epos.bh) {
 640                                 UDF_I_LENALLOC(table) += adsize;
 641                                 mark_inode_dirty(table);
 642                         } else {
 643                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 644                                 aed->lengthAllocDescs =
 645                                         cpu_to_le32(le32_to_cpu(
 646                                             aed->lengthAllocDescs) + adsize);
 647                                 udf_update_tag(epos.bh->b_data, epos.offset);
 648                                 mark_buffer_dirty(epos.bh);
 649                         }
 650                 }
 651         }
 652
 653         brelse(epos.bh);
 654         brelse(oepos.bh);
 655
 656 error_return:
 657         sb->s_dirt = 1;
 658         mutex_unlock(&sbi->s_alloc_mutex);
 659         return;
 660 }
 661
 662 static int udf_table_prealloc_blocks(struct super_block *sb,
 663                                      struct inode *inode,
 664                                      struct inode *table, uint16_t partition,
 665                                      uint32_t first_block, uint32_t block_count)
 666 {
 667         struct udf_sb_info *sbi = UDF_SB(sb);
 668         int alloc_count = 0;
 669         uint32_t elen, adsize;
 670         kernel_lb_addr eloc;
 671         struct extent_position epos;
 672         int8_t etype = -1;
 673
 674         if (first_block < 0 ||
 675                 first_block >= sbi->s_partmaps[partition].s_partition_len)
 676                 return 0;
 677
 678         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 679                 adsize = sizeof(short_ad);
 680         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 681                 adsize = sizeof(long_ad);
 682         else
 683                 return 0;
 684
 685         mutex_lock(&sbi->s_alloc_mutex);
 686         epos.offset = sizeof(struct unallocSpaceEntry);
 687         epos.block = UDF_I_LOCATION(table);
 688         epos.bh = NULL;
 689         eloc.logicalBlockNum = 0xFFFFFFFF;
 690
 691         while (first_block != eloc.logicalBlockNum &&
 692                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 693                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 694                           eloc.logicalBlockNum, elen, first_block);
 695                 ; /* empty loop body */
 696         }
 697
 698         if (first_block == eloc.logicalBlockNum) {
 699                 epos.offset -= adsize;
 700
 701                 alloc_count = (elen >> sb->s_blocksize_bits);
 702                 if (inode && DQUOT_PREALLOC_BLOCK(inode,
 703                         alloc_count > block_count ? block_count : alloc_count))
 704                         alloc_count = 0;
 705                 else if (alloc_count > block_count) {
 706                         alloc_count = block_count;
 707                         eloc.logicalBlockNum += alloc_count;
 708                         elen -= (alloc_count << sb->s_blocksize_bits);
 709                         udf_write_aext(table, &epos, eloc,
 710                                         (etype << 30) | elen, 1);
 711                 } else
 712                         udf_delete_aext(table, epos, eloc,
 713                                         (etype << 30) | elen);
 714         } else {
 715                 alloc_count = 0;
 716         }
 717
 718         brelse(epos.bh);
 719
 720         if (alloc_count && udf_add_free_space(sbi, partition, -alloc_count)) {
 721                 mark_buffer_dirty(sbi->s_lvid_bh);
 722                 sb->s_dirt = 1;
 723         }
 724         mutex_unlock(&sbi->s_alloc_mutex);
 725         return alloc_count;
 726 }
 727
 728 static int udf_table_new_block(struct super_block *sb,
 729                                struct inode *inode,
 730                                struct inode *table, uint16_t partition,
 731                                uint32_t goal, int *err)
 732 {
 733         struct udf_sb_info *sbi = UDF_SB(sb);
 734         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 735         uint32_t newblock = 0, adsize;
 736         uint32_t elen, goal_elen = 0;
 737         kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 738         struct extent_position epos, goal_epos;
 739         int8_t etype;
 740
 741         *err = -ENOSPC;
 742
 743         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 744                 adsize = sizeof(short_ad);
 745         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 746                 adsize = sizeof(long_ad);
 747         else
 748                 return newblock;
 749
 750         mutex_lock(&sbi->s_alloc_mutex);
 751         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 752                 goal = 0;
 753
 754         /* We search for the closest matching block to goal. If we find
 755            a exact hit, we stop. Otherwise we keep going till we run out
 756            of extents. We store the buffer_head, bloc, and extoffset
 757            of the current closest match and use that when we are done.
 758          */
 759         epos.offset = sizeof(struct unallocSpaceEntry);
 760         epos.block = UDF_I_LOCATION(table);
 761         epos.bh = goal_epos.bh = NULL;
 762
 763         while (spread &&
 764                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 765                 if (goal >= eloc.logicalBlockNum) {
 766                         if (goal < eloc.logicalBlockNum +
 767                                         (elen >> sb->s_blocksize_bits))
 768                                 nspread = 0;
 769                         else
 770                                 nspread = goal - eloc.logicalBlockNum -
 771                                         (elen >> sb->s_blocksize_bits);
 772                 } else {
 773                         nspread = eloc.logicalBlockNum - goal;
 774                 }
 775
 776                 if (nspread < spread) {
 777                         spread = nspread;
 778                         if (goal_epos.bh != epos.bh) {
 779                                 brelse(goal_epos.bh);
 780                                 goal_epos.bh = epos.bh;
 781                                 get_bh(goal_epos.bh);
 782                         }
 783                         goal_epos.block = epos.block;
 784                         goal_epos.offset = epos.offset - adsize;
 785                         goal_eloc = eloc;
 786                         goal_elen = (etype << 30) | elen;
 787                 }
 788         }
 789
 790         brelse(epos.bh);
 791
 792         if (spread == 0xFFFFFFFF) {
 793                 brelse(goal_epos.bh);
 794                 mutex_unlock(&sbi->s_alloc_mutex);
 795                 return 0;
 796         }
 797
 798         /* Only allocate blocks from the beginning of the extent.
 799            That way, we only delete (empty) extents, never have to insert an
 800            extent because of splitting */
 801         /* This works, but very poorly.... */
 802
 803         newblock = goal_eloc.logicalBlockNum;
 804         goal_eloc.logicalBlockNum++;
 805         goal_elen -= sb->s_blocksize;
 806
 807         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 808                 brelse(goal_epos.bh);
 809                 mutex_unlock(&sbi->s_alloc_mutex);
 810                 *err = -EDQUOT;
 811                 return 0;
 812         }
 813
 814         if (goal_elen)
 815                 udf_write_aext(table, &goal_epos, goal_eloc, goal_elen, 1);
 816         else
 817                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 818         brelse(goal_epos.bh);
 819
 820         if (udf_add_free_space(sbi, partition, -1))
 821                 mark_buffer_dirty(sbi->s_lvid_bh);
 822
 823         sb->s_dirt = 1;
 824         mutex_unlock(&sbi->s_alloc_mutex);
 825         *err = 0;
 826         return newblock;
 827 }
 828
 829 inline void udf_free_blocks(struct super_block *sb,
 830                             struct inode *inode,
 831                             kernel_lb_addr bloc, uint32_t offset,
 832                             uint32_t count)
 833 {
 834         uint16_t partition = bloc.partitionReferenceNum;
 835         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 836
 837         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 838                 return udf_bitmap_free_blocks(sb, inode,
 839                                               map->s_uspace.s_bitmap,
 840                                               bloc, offset, count);
 841         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 842                 return udf_table_free_blocks(sb, inode,
 843                                              map->s_uspace.s_table,
 844                                              bloc, offset, count);
 845         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 846                 return udf_bitmap_free_blocks(sb, inode,
 847                                               map->s_fspace.s_bitmap,
 848                                               bloc, offset, count);
 849         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 850                 return udf_table_free_blocks(sb, inode,
 851                                              map->s_fspace.s_table,
 852                                              bloc, offset, count);
 853         } else {
 854                 return;
 855         }
 856 }
 857
 858 inline int udf_prealloc_blocks(struct super_block *sb,
 859                                struct inode *inode,
 860                                uint16_t partition, uint32_t first_block,
 861                                uint32_t block_count)
 862 {
 863         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 864
 865         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 866                 return udf_bitmap_prealloc_blocks(sb, inode,
 867                                                   map->s_uspace.s_bitmap,
 868                                                   partition, first_block,
 869                                                   block_count);
 870         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 871                 return udf_table_prealloc_blocks(sb, inode,
 872                                                  map->s_uspace.s_table,
 873                                                  partition, first_block,
 874                                                  block_count);
 875         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 876                 return udf_bitmap_prealloc_blocks(sb, inode,
 877                                                   map->s_fspace.s_bitmap,
 878                                                   partition, first_block,
 879                                                   block_count);
 880         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 881                 return udf_table_prealloc_blocks(sb, inode,
 882                                                  map->s_fspace.s_table,
 883                                                  partition, first_block,
 884                                                  block_count);
 885         else
 886                 return 0;
 887 }
 888
 889 inline int udf_new_block(struct super_block *sb,
 890                          struct inode *inode,
 891                          uint16_t partition, uint32_t goal, int *err)
 892 {
 893         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 894
 895         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 896                 return udf_bitmap_new_block(sb, inode,
 897                                            map->s_uspace.s_bitmap,
 898                                            partition, goal, err);
 899         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 900                 return udf_table_new_block(sb, inode,
 901                                            map->s_uspace.s_table,
 902                                            partition, goal, err);
 903         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 904                 return udf_bitmap_new_block(sb, inode,
 905                                             map->s_fspace.s_bitmap,
 906                                             partition, goal, err);
 907         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 908                 return udf_table_new_block(sb, inode,
 909                                            map->s_fspace.s_table,
 910                                            partition, goal, err);
 911         else {
 912                 *err = -EIO;
 913                 return 0;
 914         }
 915 }