git.oblomov.eu Git - linux-2.6/blob - 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                                         vfs_dq_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 < 0 || 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 (vfs_dq_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                                 vfs_dq_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 < 0 || 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 && vfs_dq_alloc_block(inode, 1)) {
 394                 mutex_unlock(&sbi->s_alloc_mutex);
 395                 *err = -EDQUOT;
 396                 return 0;
 397         }
 398
 399         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 400                 (sizeof(struct spaceBitmapDesc) << 3);
 401
 402         if (!udf_clear_bit(bit, bh->b_data)) {
 403                 udf_debug("bit already cleared for block %d\n", bit);
 404                 goto repeat;
 405         }
 406
 407         mark_buffer_dirty(bh);
 408
 409         udf_add_free_space(sb, partition, -1);
 410         mutex_unlock(&sbi->s_alloc_mutex);
 411         *err = 0;
 412         return newblock;
 413
 414 error_return:
 415         *err = -EIO;
 416         mutex_unlock(&sbi->s_alloc_mutex);
 417         return 0;
 418 }
 419
 420 static void udf_table_free_blocks(struct super_block *sb,
 421                                   struct inode *inode,
 422                                   struct inode *table,
 423                                   struct kernel_lb_addr *bloc,
 424                                   uint32_t offset,
 425                                   uint32_t count)
 426 {
 427         struct udf_sb_info *sbi = UDF_SB(sb);
 428         struct udf_part_map *partmap;
 429         uint32_t start, end;
 430         uint32_t elen;
 431         struct kernel_lb_addr eloc;
 432         struct extent_position oepos, epos;
 433         int8_t etype;
 434         int i;
 435         struct udf_inode_info *iinfo;
 436
 437         mutex_lock(&sbi->s_alloc_mutex);
 438         partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 439         if (bloc->logicalBlockNum < 0 ||
 440             (bloc->logicalBlockNum + count) >
 441                 partmap->s_partition_len) {
 442                 udf_debug("%d < %d || %d + %d > %d\n",
 443                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 444                           partmap->s_partition_len);
 445                 goto error_return;
 446         }
 447
 448         iinfo = UDF_I(table);
 449         /* We do this up front - There are some error conditions that
 450            could occure, but.. oh well */
 451         if (inode)
 452                 vfs_dq_free_block(inode, count);
 453         udf_add_free_space(sb, sbi->s_partition, count);
 454
 455         start = bloc->logicalBlockNum + offset;
 456         end = bloc->logicalBlockNum + offset + count - 1;
 457
 458         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 459         elen = 0;
 460         epos.block = oepos.block = iinfo->i_location;
 461         epos.bh = oepos.bh = NULL;
 462
 463         while (count &&
 464                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 465                 if (((eloc.logicalBlockNum +
 466                         (elen >> sb->s_blocksize_bits)) == start)) {
 467                         if ((0x3FFFFFFF - elen) <
 468                                         (count << sb->s_blocksize_bits)) {
 469                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 470                                                         sb->s_blocksize_bits);
 471                                 count -= tmp;
 472                                 start += tmp;
 473                                 elen = (etype << 30) |
 474                                         (0x40000000 - sb->s_blocksize);
 475                         } else {
 476                                 elen = (etype << 30) |
 477                                         (elen +
 478                                         (count << sb->s_blocksize_bits));
 479                                 start += count;
 480                                 count = 0;
 481                         }
 482                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 483                 } else if (eloc.logicalBlockNum == (end + 1)) {
 484                         if ((0x3FFFFFFF - elen) <
 485                                         (count << sb->s_blocksize_bits)) {
 486                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 487                                                 sb->s_blocksize_bits);
 488                                 count -= tmp;
 489                                 end -= tmp;
 490                                 eloc.logicalBlockNum -= tmp;
 491                                 elen = (etype << 30) |
 492                                         (0x40000000 - sb->s_blocksize);
 493                         } else {
 494                                 eloc.logicalBlockNum = start;
 495                                 elen = (etype << 30) |
 496                                         (elen +
 497                                         (count << sb->s_blocksize_bits));
 498                                 end -= count;
 499                                 count = 0;
 500                         }
 501                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 502                 }
 503
 504                 if (epos.bh != oepos.bh) {
 505                         i = -1;
 506                         oepos.block = epos.block;
 507                         brelse(oepos.bh);
 508                         get_bh(epos.bh);
 509                         oepos.bh = epos.bh;
 510                         oepos.offset = 0;
 511                 } else {
 512                         oepos.offset = epos.offset;
 513                 }
 514         }
 515
 516         if (count) {
 517                 /*
 518                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
 519                  * allocate a new block, and since we hold the super block
 520                  * lock already very bad things would happen :)
 521                  *
 522                  * We copy the behavior of udf_add_aext, but instead of
 523                  * trying to allocate a new block close to the existing one,
 524                  * we just steal a block from the extent we are trying to add.
 525                  *
 526                  * It would be nice if the blocks were close together, but it
 527                  * isn't required.
 528                  */
 529
 530                 int adsize;
 531                 struct short_ad *sad = NULL;
 532                 struct long_ad *lad = NULL;
 533                 struct allocExtDesc *aed;
 534
 535                 eloc.logicalBlockNum = start;
 536                 elen = EXT_RECORDED_ALLOCATED |
 537                         (count << sb->s_blocksize_bits);
 538
 539                 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 540                         adsize = sizeof(struct short_ad);
 541                 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 542                         adsize = sizeof(struct long_ad);
 543                 else {
 544                         brelse(oepos.bh);
 545                         brelse(epos.bh);
 546                         goto error_return;
 547                 }
 548
 549                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 550                         char *sptr, *dptr;
 551                         int loffset;
 552
 553                         brelse(oepos.bh);
 554                         oepos = epos;
 555
 556                         /* Steal a block from the extent being free'd */
 557                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 558                         eloc.logicalBlockNum++;
 559                         elen -= sb->s_blocksize;
 560
 561                         epos.bh = udf_tread(sb,
 562                                         udf_get_lb_pblock(sb, &epos.block, 0));
 563                         if (!epos.bh) {
 564                                 brelse(oepos.bh);
 565                                 goto error_return;
 566                         }
 567                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 568                         aed->previousAllocExtLocation =
 569                                 cpu_to_le32(oepos.block.logicalBlockNum);
 570                         if (epos.offset + adsize > sb->s_blocksize) {
 571                                 loffset = epos.offset;
 572                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 573                                 sptr = iinfo->i_ext.i_data + epos.offset
 574                                                                 - adsize;
 575                                 dptr = epos.bh->b_data +
 576                                         sizeof(struct allocExtDesc);
 577                                 memcpy(dptr, sptr, adsize);
 578                                 epos.offset = sizeof(struct allocExtDesc) +
 579                                                 adsize;
 580                         } else {
 581                                 loffset = epos.offset + adsize;
 582                                 aed->lengthAllocDescs = cpu_to_le32(0);
 583                                 if (oepos.bh) {
 584                                         sptr = oepos.bh->b_data + epos.offset;
 585                                         aed = (struct allocExtDesc *)
 586                                                 oepos.bh->b_data;
 587                                         le32_add_cpu(&aed->lengthAllocDescs,
 588                                                         adsize);
 589                                 } else {
 590                                         sptr = iinfo->i_ext.i_data +
 591                                                                 epos.offset;
 592                                         iinfo->i_lenAlloc += adsize;
 593                                         mark_inode_dirty(table);
 594                                 }
 595                                 epos.offset = sizeof(struct allocExtDesc);
 596                         }
 597                         if (sbi->s_udfrev >= 0x0200)
 598                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 599                                             3, 1, epos.block.logicalBlockNum,
 600                                             sizeof(struct tag));
 601                         else
 602                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 603                                             2, 1, epos.block.logicalBlockNum,
 604                                             sizeof(struct tag));
 605
 606                         switch (iinfo->i_alloc_type) {
 607                         case ICBTAG_FLAG_AD_SHORT:
 608                                 sad = (struct short_ad *)sptr;
 609                                 sad->extLength = cpu_to_le32(
 610                                         EXT_NEXT_EXTENT_ALLOCDECS |
 611                                         sb->s_blocksize);
 612                                 sad->extPosition =
 613                                         cpu_to_le32(epos.block.logicalBlockNum);
 614                                 break;
 615                         case ICBTAG_FLAG_AD_LONG:
 616                                 lad = (struct long_ad *)sptr;
 617                                 lad->extLength = cpu_to_le32(
 618                                         EXT_NEXT_EXTENT_ALLOCDECS |
 619                                         sb->s_blocksize);
 620                                 lad->extLocation =
 621                                         cpu_to_lelb(epos.block);
 622                                 break;
 623                         }
 624                         if (oepos.bh) {
 625                                 udf_update_tag(oepos.bh->b_data, loffset);
 626                                 mark_buffer_dirty(oepos.bh);
 627                         } else {
 628                                 mark_inode_dirty(table);
 629                         }
 630                 }
 631
 632                 /* It's possible that stealing the block emptied the extent */
 633                 if (elen) {
 634                         udf_write_aext(table, &epos, &eloc, elen, 1);
 635
 636                         if (!epos.bh) {
 637                                 iinfo->i_lenAlloc += adsize;
 638                                 mark_inode_dirty(table);
 639                         } else {
 640                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 641                                 le32_add_cpu(&aed->lengthAllocDescs, adsize);
 642                                 udf_update_tag(epos.bh->b_data, epos.offset);
 643                                 mark_buffer_dirty(epos.bh);
 644                         }
 645                 }
 646         }
 647
 648         brelse(epos.bh);
 649         brelse(oepos.bh);
 650
 651 error_return:
 652         mutex_unlock(&sbi->s_alloc_mutex);
 653         return;
 654 }
 655
 656 static int udf_table_prealloc_blocks(struct super_block *sb,
 657                                      struct inode *inode,
 658                                      struct inode *table, uint16_t partition,
 659                                      uint32_t first_block, uint32_t block_count)
 660 {
 661         struct udf_sb_info *sbi = UDF_SB(sb);
 662         int alloc_count = 0;
 663         uint32_t elen, adsize;
 664         struct kernel_lb_addr eloc;
 665         struct extent_position epos;
 666         int8_t etype = -1;
 667         struct udf_inode_info *iinfo;
 668
 669         if (first_block < 0 ||
 670                 first_block >= sbi->s_partmaps[partition].s_partition_len)
 671                 return 0;
 672
 673         iinfo = UDF_I(table);
 674         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 675                 adsize = sizeof(struct short_ad);
 676         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 677                 adsize = sizeof(struct long_ad);
 678         else
 679                 return 0;
 680
 681         mutex_lock(&sbi->s_alloc_mutex);
 682         epos.offset = sizeof(struct unallocSpaceEntry);
 683         epos.block = iinfo->i_location;
 684         epos.bh = NULL;
 685         eloc.logicalBlockNum = 0xFFFFFFFF;
 686
 687         while (first_block != eloc.logicalBlockNum &&
 688                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 689                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 690                           eloc.logicalBlockNum, elen, first_block);
 691                 ; /* empty loop body */
 692         }
 693
 694         if (first_block == eloc.logicalBlockNum) {
 695                 epos.offset -= adsize;
 696
 697                 alloc_count = (elen >> sb->s_blocksize_bits);
 698                 if (inode && vfs_dq_prealloc_block(inode,
 699                         alloc_count > block_count ? block_count : alloc_count))
 700                         alloc_count = 0;
 701                 else if (alloc_count > block_count) {
 702                         alloc_count = block_count;
 703                         eloc.logicalBlockNum += alloc_count;
 704                         elen -= (alloc_count << sb->s_blocksize_bits);
 705                         udf_write_aext(table, &epos, &eloc,
 706                                         (etype << 30) | elen, 1);
 707                 } else
 708                         udf_delete_aext(table, epos, eloc,
 709                                         (etype << 30) | elen);
 710         } else {
 711                 alloc_count = 0;
 712         }
 713
 714         brelse(epos.bh);
 715
 716         if (alloc_count)
 717                 udf_add_free_space(sb, partition, -alloc_count);
 718         mutex_unlock(&sbi->s_alloc_mutex);
 719         return alloc_count;
 720 }
 721
 722 static int udf_table_new_block(struct super_block *sb,
 723                                struct inode *inode,
 724                                struct inode *table, uint16_t partition,
 725                                uint32_t goal, int *err)
 726 {
 727         struct udf_sb_info *sbi = UDF_SB(sb);
 728         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 729         uint32_t newblock = 0, adsize;
 730         uint32_t elen, goal_elen = 0;
 731         struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 732         struct extent_position epos, goal_epos;
 733         int8_t etype;
 734         struct udf_inode_info *iinfo = UDF_I(table);
 735
 736         *err = -ENOSPC;
 737
 738         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 739                 adsize = sizeof(struct short_ad);
 740         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 741                 adsize = sizeof(struct long_ad);
 742         else
 743                 return newblock;
 744
 745         mutex_lock(&sbi->s_alloc_mutex);
 746         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 747                 goal = 0;
 748
 749         /* We search for the closest matching block to goal. If we find
 750            a exact hit, we stop. Otherwise we keep going till we run out
 751            of extents. We store the buffer_head, bloc, and extoffset
 752            of the current closest match and use that when we are done.
 753          */
 754         epos.offset = sizeof(struct unallocSpaceEntry);
 755         epos.block = iinfo->i_location;
 756         epos.bh = goal_epos.bh = NULL;
 757
 758         while (spread &&
 759                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 760                 if (goal >= eloc.logicalBlockNum) {
 761                         if (goal < eloc.logicalBlockNum +
 762                                         (elen >> sb->s_blocksize_bits))
 763                                 nspread = 0;
 764                         else
 765                                 nspread = goal - eloc.logicalBlockNum -
 766                                         (elen >> sb->s_blocksize_bits);
 767                 } else {
 768                         nspread = eloc.logicalBlockNum - goal;
 769                 }
 770
 771                 if (nspread < spread) {
 772                         spread = nspread;
 773                         if (goal_epos.bh != epos.bh) {
 774                                 brelse(goal_epos.bh);
 775                                 goal_epos.bh = epos.bh;
 776                                 get_bh(goal_epos.bh);
 777                         }
 778                         goal_epos.block = epos.block;
 779                         goal_epos.offset = epos.offset - adsize;
 780                         goal_eloc = eloc;
 781                         goal_elen = (etype << 30) | elen;
 782                 }
 783         }
 784
 785         brelse(epos.bh);
 786
 787         if (spread == 0xFFFFFFFF) {
 788                 brelse(goal_epos.bh);
 789                 mutex_unlock(&sbi->s_alloc_mutex);
 790                 return 0;
 791         }
 792
 793         /* Only allocate blocks from the beginning of the extent.
 794            That way, we only delete (empty) extents, never have to insert an
 795            extent because of splitting */
 796         /* This works, but very poorly.... */
 797
 798         newblock = goal_eloc.logicalBlockNum;
 799         goal_eloc.logicalBlockNum++;
 800         goal_elen -= sb->s_blocksize;
 801
 802         if (inode && vfs_dq_alloc_block(inode, 1)) {
 803                 brelse(goal_epos.bh);
 804                 mutex_unlock(&sbi->s_alloc_mutex);
 805                 *err = -EDQUOT;
 806                 return 0;
 807         }
 808
 809         if (goal_elen)
 810                 udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
 811         else
 812                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 813         brelse(goal_epos.bh);
 814
 815         udf_add_free_space(sb, partition, -1);
 816
 817         mutex_unlock(&sbi->s_alloc_mutex);
 818         *err = 0;
 819         return newblock;
 820 }
 821
 822 void udf_free_blocks(struct super_block *sb, struct inode *inode,
 823                      struct kernel_lb_addr *bloc, uint32_t offset,
 824                      uint32_t count)
 825 {
 826         uint16_t partition = bloc->partitionReferenceNum;
 827         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 828
 829         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 830                 udf_bitmap_free_blocks(sb, inode, map->s_uspace.s_bitmap,
 831                                        bloc, offset, count);
 832         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 833                 udf_table_free_blocks(sb, inode, map->s_uspace.s_table,
 834                                       bloc, offset, count);
 835         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 836                 udf_bitmap_free_blocks(sb, inode, map->s_fspace.s_bitmap,
 837                                        bloc, offset, count);
 838         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 839                 udf_table_free_blocks(sb, inode, map->s_fspace.s_table,
 840                                       bloc, offset, count);
 841         }
 842 }
 843
 844 inline int udf_prealloc_blocks(struct super_block *sb,
 845                                struct inode *inode,
 846                                uint16_t partition, uint32_t first_block,
 847                                uint32_t block_count)
 848 {
 849         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 850
 851         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 852                 return udf_bitmap_prealloc_blocks(sb, inode,
 853                                                   map->s_uspace.s_bitmap,
 854                                                   partition, first_block,
 855                                                   block_count);
 856         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 857                 return udf_table_prealloc_blocks(sb, inode,
 858                                                  map->s_uspace.s_table,
 859                                                  partition, first_block,
 860                                                  block_count);
 861         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 862                 return udf_bitmap_prealloc_blocks(sb, inode,
 863                                                   map->s_fspace.s_bitmap,
 864                                                   partition, first_block,
 865                                                   block_count);
 866         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 867                 return udf_table_prealloc_blocks(sb, inode,
 868                                                  map->s_fspace.s_table,
 869                                                  partition, first_block,
 870                                                  block_count);
 871         else
 872                 return 0;
 873 }
 874
 875 inline int udf_new_block(struct super_block *sb,
 876                          struct inode *inode,
 877                          uint16_t partition, uint32_t goal, int *err)
 878 {
 879         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 880
 881         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 882                 return udf_bitmap_new_block(sb, inode,
 883                                            map->s_uspace.s_bitmap,
 884                                            partition, goal, err);
 885         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 886                 return udf_table_new_block(sb, inode,
 887                                            map->s_uspace.s_table,
 888                                            partition, goal, err);
 889         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 890                 return udf_bitmap_new_block(sb, inode,
 891                                             map->s_fspace.s_bitmap,
 892                                             partition, goal, err);
 893         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 894                 return udf_table_new_block(sb, inode,
 895                                            map->s_fspace.s_table,
 896                                            partition, goal, err);
 897         else {
 898                 *err = -EIO;
 899                 return 0;
 900         }
 901 }