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         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_bitmap_free_blocks(struct super_block *sb,
 144                                    struct inode *inode,
 145                                    struct udf_bitmap *bitmap,
 146                                    kernel_lb_addr bloc, uint32_t offset,
 147                                    uint32_t count)
 148 {
 149         struct udf_sb_info *sbi = UDF_SB(sb);
 150         struct buffer_head *bh = NULL;
 151         unsigned long block;
 152         unsigned long block_group;
 153         unsigned long bit;
 154         unsigned long i;
 155         int bitmap_nr;
 156         unsigned long overflow;
 157
 158         mutex_lock(&sbi->s_alloc_mutex);
 159         if (bloc.logicalBlockNum < 0 ||
 160             (bloc.logicalBlockNum + count) >
 161                 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
 162                 udf_debug("%d < %d || %d + %d > %d\n",
 163                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 164                           sbi->s_partmaps[bloc.partitionReferenceNum].
 165                                                         s_partition_len);
 166                 goto error_return;
 167         }
 168
 169         block = bloc.logicalBlockNum + offset +
 170                 (sizeof(struct spaceBitmapDesc) << 3);
 171
 172 do_more:
 173         overflow = 0;
 174         block_group = block >> (sb->s_blocksize_bits + 3);
 175         bit = block % (sb->s_blocksize << 3);
 176
 177         /*
 178          * Check to see if we are freeing blocks across a group boundary.
 179          */
 180         if (bit + count > (sb->s_blocksize << 3)) {
 181                 overflow = bit + count - (sb->s_blocksize << 3);
 182                 count -= overflow;
 183         }
 184         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 185         if (bitmap_nr < 0)
 186                 goto error_return;
 187
 188         bh = bitmap->s_block_bitmap[bitmap_nr];
 189         for (i = 0; i < count; i++) {
 190                 if (udf_set_bit(bit + i, bh->b_data)) {
 191                         udf_debug("bit %ld already set\n", bit + i);
 192                         udf_debug("byte=%2x\n",
 193                                   ((char *)bh->b_data)[(bit + i) >> 3]);
 194                 } else {
 195                         if (inode)
 196                                 DQUOT_FREE_BLOCK(inode, 1);
 197                         if (sbi->s_lvid_bh) {
 198                                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 199                                 lvid->freeSpaceTable[sbi->s_partition] =
 200                                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[sbi->s_partition]) + 1);
 201                         }
 202                 }
 203         }
 204         mark_buffer_dirty(bh);
 205         if (overflow) {
 206                 block += count;
 207                 count = overflow;
 208                 goto do_more;
 209         }
 210 error_return:
 211         sb->s_dirt = 1;
 212         if (sbi->s_lvid_bh)
 213                 mark_buffer_dirty(sbi->s_lvid_bh);
 214         mutex_unlock(&sbi->s_alloc_mutex);
 215         return;
 216 }
 217
 218 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 219                                       struct inode *inode,
 220                                       struct udf_bitmap *bitmap,
 221                                       uint16_t partition, uint32_t first_block,
 222                                       uint32_t block_count)
 223 {
 224         struct udf_sb_info *sbi = UDF_SB(sb);
 225         int alloc_count = 0;
 226         int bit, block, block_group, group_start;
 227         int nr_groups, bitmap_nr;
 228         struct buffer_head *bh;
 229         __u32 part_len;
 230
 231         mutex_lock(&sbi->s_alloc_mutex);
 232         part_len = sbi->s_partmaps[partition].s_partition_len;
 233         if (first_block < 0 || first_block >= part_len)
 234                 goto out;
 235
 236         if (first_block + block_count > part_len)
 237                 block_count = part_len - first_block;
 238
 239 repeat:
 240         nr_groups = udf_compute_nr_groups(sb, partition);
 241         block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 242         block_group = block >> (sb->s_blocksize_bits + 3);
 243         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 244
 245         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 246         if (bitmap_nr < 0)
 247                 goto out;
 248         bh = bitmap->s_block_bitmap[bitmap_nr];
 249
 250         bit = block % (sb->s_blocksize << 3);
 251
 252         while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 253                 if (!udf_test_bit(bit, bh->b_data)) {
 254                         goto out;
 255                 } else if (DQUOT_PREALLOC_BLOCK(inode, 1)) {
 256                         goto out;
 257                 } else if (!udf_clear_bit(bit, bh->b_data)) {
 258                         udf_debug("bit already cleared for block %d\n", bit);
 259                         DQUOT_FREE_BLOCK(inode, 1);
 260                         goto out;
 261                 }
 262                 block_count--;
 263                 alloc_count++;
 264                 bit++;
 265                 block++;
 266         }
 267         mark_buffer_dirty(bh);
 268         if (block_count > 0)
 269                 goto repeat;
 270 out:
 271         if (sbi->s_lvid_bh) {
 272                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 273                 lvid->freeSpaceTable[partition] =
 274                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - alloc_count);
 275                 mark_buffer_dirty(sbi->s_lvid_bh);
 276         }
 277         sb->s_dirt = 1;
 278         mutex_unlock(&sbi->s_alloc_mutex);
 279         return alloc_count;
 280 }
 281
 282 static int udf_bitmap_new_block(struct super_block *sb,
 283                                 struct inode *inode,
 284                                 struct udf_bitmap *bitmap, uint16_t partition,
 285                                 uint32_t goal, int *err)
 286 {
 287         struct udf_sb_info *sbi = UDF_SB(sb);
 288         int newbit, bit = 0, block, block_group, group_start;
 289         int end_goal, nr_groups, bitmap_nr, i;
 290         struct buffer_head *bh = NULL;
 291         char *ptr;
 292         int newblock = 0;
 293
 294         *err = -ENOSPC;
 295         mutex_lock(&sbi->s_alloc_mutex);
 296
 297 repeat:
 298         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 299                 goal = 0;
 300
 301         nr_groups = bitmap->s_nr_groups;
 302         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 303         block_group = block >> (sb->s_blocksize_bits + 3);
 304         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 305
 306         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 307         if (bitmap_nr < 0)
 308                 goto error_return;
 309         bh = bitmap->s_block_bitmap[bitmap_nr];
 310         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 311                       sb->s_blocksize - group_start);
 312
 313         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 314                 bit = block % (sb->s_blocksize << 3);
 315                 if (udf_test_bit(bit, bh->b_data))
 316                         goto got_block;
 317
 318                 end_goal = (bit + 63) & ~63;
 319                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 320                 if (bit < end_goal)
 321                         goto got_block;
 322
 323                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
 324                               sb->s_blocksize - ((bit + 7) >> 3));
 325                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 326                 if (newbit < sb->s_blocksize << 3) {
 327                         bit = newbit;
 328                         goto search_back;
 329                 }
 330
 331                 newbit = udf_find_next_one_bit(bh->b_data,
 332                                                sb->s_blocksize << 3, bit);
 333                 if (newbit < sb->s_blocksize << 3) {
 334                         bit = newbit;
 335                         goto got_block;
 336                 }
 337         }
 338
 339         for (i = 0; i < (nr_groups * 2); i++) {
 340                 block_group++;
 341                 if (block_group >= nr_groups)
 342                         block_group = 0;
 343                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 344
 345                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 346                 if (bitmap_nr < 0)
 347                         goto error_return;
 348                 bh = bitmap->s_block_bitmap[bitmap_nr];
 349                 if (i < nr_groups) {
 350                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 351                                       sb->s_blocksize - group_start);
 352                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 353                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 354                                 break;
 355                         }
 356                 } else {
 357                         bit = udf_find_next_one_bit((char *)bh->b_data,
 358                                                     sb->s_blocksize << 3,
 359                                                     group_start << 3);
 360                         if (bit < sb->s_blocksize << 3)
 361                                 break;
 362                 }
 363         }
 364         if (i >= (nr_groups * 2)) {
 365                 mutex_unlock(&sbi->s_alloc_mutex);
 366                 return newblock;
 367         }
 368         if (bit < sb->s_blocksize << 3)
 369                 goto search_back;
 370         else
 371                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
 372                                             group_start << 3);
 373         if (bit >= sb->s_blocksize << 3) {
 374                 mutex_unlock(&sbi->s_alloc_mutex);
 375                 return 0;
 376         }
 377
 378 search_back:
 379         i = 0;
 380         while (i < 7 && bit > (group_start << 3) &&
 381                udf_test_bit(bit - 1, bh->b_data)) {
 382                 ++i;
 383                 --bit;
 384         }
 385
 386 got_block:
 387
 388         /*
 389          * Check quota for allocation of this block.
 390          */
 391         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 392                 mutex_unlock(&sbi->s_alloc_mutex);
 393                 *err = -EDQUOT;
 394                 return 0;
 395         }
 396
 397         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 398                 (sizeof(struct spaceBitmapDesc) << 3);
 399
 400         if (!udf_clear_bit(bit, bh->b_data)) {
 401                 udf_debug("bit already cleared for block %d\n", bit);
 402                 goto repeat;
 403         }
 404
 405         mark_buffer_dirty(bh);
 406
 407         if (sbi->s_lvid_bh) {
 408                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 409                 lvid->freeSpaceTable[partition] =
 410                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - 1);
 411                 mark_buffer_dirty(sbi->s_lvid_bh);
 412         }
 413         sb->s_dirt = 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                                   kernel_lb_addr bloc, uint32_t offset,
 428                                   uint32_t count)
 429 {
 430         struct udf_sb_info *sbi = UDF_SB(sb);
 431         uint32_t start, end;
 432         uint32_t elen;
 433         kernel_lb_addr eloc;
 434         struct extent_position oepos, epos;
 435         int8_t etype;
 436         int i;
 437
 438         mutex_lock(&sbi->s_alloc_mutex);
 439         if (bloc.logicalBlockNum < 0 ||
 440             (bloc.logicalBlockNum + count) >
 441                 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
 442                 udf_debug("%d < %d || %d + %d > %d\n",
 443                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 444                           sbi->s_partmaps[bloc.partitionReferenceNum].
 445                                                         s_partition_len);
 446                 goto error_return;
 447         }
 448
 449         /* We do this up front - There are some error conditions that
 450            could occure, but.. oh well */
 451         if (inode)
 452                 DQUOT_FREE_BLOCK(inode, count);
 453         if (sbi->s_lvid_bh) {
 454                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 455                 lvid->freeSpaceTable[sbi->s_partition] =
 456                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[sbi->s_partition]) + count);
 457                 mark_buffer_dirty(sbi->s_lvid_bh);
 458         }
 459
 460         start = bloc.logicalBlockNum + offset;
 461         end = bloc.logicalBlockNum + offset + count - 1;
 462
 463         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 464         elen = 0;
 465         epos.block = oepos.block = UDF_I_LOCATION(table);
 466         epos.bh = oepos.bh = NULL;
 467
 468         while (count &&
 469                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 470                 if (((eloc.logicalBlockNum +
 471                         (elen >> sb->s_blocksize_bits)) == start)) {
 472                         if ((0x3FFFFFFF - elen) <
 473                                         (count << sb->s_blocksize_bits)) {
 474                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 475                                                         sb->s_blocksize_bits);
 476                                 count -= tmp;
 477                                 start += tmp;
 478                                 elen = (etype << 30) |
 479                                         (0x40000000 - sb->s_blocksize);
 480                         } else {
 481                                 elen = (etype << 30) |
 482                                         (elen +
 483                                         (count << sb->s_blocksize_bits));
 484                                 start += count;
 485                                 count = 0;
 486                         }
 487                         udf_write_aext(table, &oepos, eloc, elen, 1);
 488                 } else if (eloc.logicalBlockNum == (end + 1)) {
 489                         if ((0x3FFFFFFF - elen) <
 490                                         (count << sb->s_blocksize_bits)) {
 491                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 492                                                 sb->s_blocksize_bits);
 493                                 count -= tmp;
 494                                 end -= tmp;
 495                                 eloc.logicalBlockNum -= tmp;
 496                                 elen = (etype << 30) |
 497                                         (0x40000000 - sb->s_blocksize);
 498                         } else {
 499                                 eloc.logicalBlockNum = start;
 500                                 elen = (etype << 30) |
 501                                         (elen +
 502                                         (count << sb->s_blocksize_bits));
 503                                 end -= count;
 504                                 count = 0;
 505                         }
 506                         udf_write_aext(table, &oepos, eloc, elen, 1);
 507                 }
 508
 509                 if (epos.bh != oepos.bh) {
 510                         i = -1;
 511                         oepos.block = epos.block;
 512                         brelse(oepos.bh);
 513                         get_bh(epos.bh);
 514                         oepos.bh = epos.bh;
 515                         oepos.offset = 0;
 516                 } else {
 517                         oepos.offset = epos.offset;
 518                 }
 519         }
 520
 521         if (count) {
 522                 /*
 523                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
 524                  * allocate a new block, and since we hold the super block
 525                  * lock already very bad things would happen :)
 526                  *
 527                  * We copy the behavior of udf_add_aext, but instead of
 528                  * trying to allocate a new block close to the existing one,
 529                  * we just steal a block from the extent we are trying to add.
 530                  *
 531                  * It would be nice if the blocks were close together, but it
 532                  * isn't required.
 533                  */
 534
 535                 int adsize;
 536                 short_ad *sad = NULL;
 537                 long_ad *lad = NULL;
 538                 struct allocExtDesc *aed;
 539
 540                 eloc.logicalBlockNum = start;
 541                 elen = EXT_RECORDED_ALLOCATED |
 542                         (count << sb->s_blocksize_bits);
 543
 544                 if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT) {
 545                         adsize = sizeof(short_ad);
 546                 } else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG) {
 547                         adsize = sizeof(long_ad);
 548                 } else {
 549                         brelse(oepos.bh);
 550                         brelse(epos.bh);
 551                         goto error_return;
 552                 }
 553
 554                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 555                         char *sptr, *dptr;
 556                         int loffset;
 557
 558                         brelse(oepos.bh);
 559                         oepos = epos;
 560
 561                         /* Steal a block from the extent being free'd */
 562                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 563                         eloc.logicalBlockNum++;
 564                         elen -= sb->s_blocksize;
 565
 566                         epos.bh = udf_tread(sb,
 567                                         udf_get_lb_pblock(sb, epos.block, 0));
 568                         if (!epos.bh) {
 569                                 brelse(oepos.bh);
 570                                 goto error_return;
 571                         }
 572                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 573                         aed->previousAllocExtLocation =
 574                                 cpu_to_le32(oepos.block.logicalBlockNum);
 575                         if (epos.offset + adsize > sb->s_blocksize) {
 576                                 loffset = epos.offset;
 577                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 578                                 sptr = UDF_I_DATA(table) + epos.offset - 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                                         aed->lengthAllocDescs =
 592                                                 cpu_to_le32(le32_to_cpu(
 593                                                         aed->lengthAllocDescs) +
 594                                                                 adsize);
 595                                 } else {
 596                                         sptr = UDF_I_DATA(table) + epos.offset;
 597                                         UDF_I_LENALLOC(table) += adsize;
 598                                         mark_inode_dirty(table);
 599                                 }
 600                                 epos.offset = sizeof(struct allocExtDesc);
 601                         }
 602                         if (sbi->s_udfrev >= 0x0200)
 603                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 604                                             3, 1, epos.block.logicalBlockNum,
 605                                             sizeof(tag));
 606                         else
 607                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 608                                             2, 1, epos.block.logicalBlockNum,
 609                                             sizeof(tag));
 610
 611                         switch (UDF_I_ALLOCTYPE(table)) {
 612                         case ICBTAG_FLAG_AD_SHORT:
 613                                 sad = (short_ad *)sptr;
 614                                 sad->extLength = cpu_to_le32(
 615                                         EXT_NEXT_EXTENT_ALLOCDECS |
 616                                         sb->s_blocksize);
 617                                 sad->extPosition =
 618                                         cpu_to_le32(epos.block.logicalBlockNum);
 619                                 break;
 620                         case ICBTAG_FLAG_AD_LONG:
 621                                 lad = (long_ad *)sptr;
 622                                 lad->extLength = cpu_to_le32(
 623                                         EXT_NEXT_EXTENT_ALLOCDECS |
 624                                         sb->s_blocksize);
 625                                 lad->extLocation =
 626                                         cpu_to_lelb(epos.block);
 627                                 break;
 628                         }
 629                         if (oepos.bh) {
 630                                 udf_update_tag(oepos.bh->b_data, loffset);
 631                                 mark_buffer_dirty(oepos.bh);
 632                         } else {
 633                                 mark_inode_dirty(table);
 634                         }
 635                 }
 636
 637                 /* It's possible that stealing the block emptied the extent */
 638                 if (elen) {
 639                         udf_write_aext(table, &epos, eloc, elen, 1);
 640
 641                         if (!epos.bh) {
 642                                 UDF_I_LENALLOC(table) += adsize;
 643                                 mark_inode_dirty(table);
 644                         } else {
 645                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 646                                 aed->lengthAllocDescs =
 647                                         cpu_to_le32(le32_to_cpu(
 648                                             aed->lengthAllocDescs) + adsize);
 649                                 udf_update_tag(epos.bh->b_data, epos.offset);
 650                                 mark_buffer_dirty(epos.bh);
 651                         }
 652                 }
 653         }
 654
 655         brelse(epos.bh);
 656         brelse(oepos.bh);
 657
 658 error_return:
 659         sb->s_dirt = 1;
 660         mutex_unlock(&sbi->s_alloc_mutex);
 661         return;
 662 }
 663
 664 static int udf_table_prealloc_blocks(struct super_block *sb,
 665                                      struct inode *inode,
 666                                      struct inode *table, uint16_t partition,
 667                                      uint32_t first_block, uint32_t block_count)
 668 {
 669         struct udf_sb_info *sbi = UDF_SB(sb);
 670         int alloc_count = 0;
 671         uint32_t elen, adsize;
 672         kernel_lb_addr eloc;
 673         struct extent_position epos;
 674         int8_t etype = -1;
 675
 676         if (first_block < 0 ||
 677                 first_block >= sbi->s_partmaps[partition].s_partition_len)
 678                 return 0;
 679
 680         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 681                 adsize = sizeof(short_ad);
 682         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 683                 adsize = sizeof(long_ad);
 684         else
 685                 return 0;
 686
 687         mutex_lock(&sbi->s_alloc_mutex);
 688         epos.offset = sizeof(struct unallocSpaceEntry);
 689         epos.block = UDF_I_LOCATION(table);
 690         epos.bh = NULL;
 691         eloc.logicalBlockNum = 0xFFFFFFFF;
 692
 693         while (first_block != eloc.logicalBlockNum &&
 694                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 695                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 696                           eloc.logicalBlockNum, elen, first_block);
 697                 ; /* empty loop body */
 698         }
 699
 700         if (first_block == eloc.logicalBlockNum) {
 701                 epos.offset -= adsize;
 702
 703                 alloc_count = (elen >> sb->s_blocksize_bits);
 704                 if (inode && DQUOT_PREALLOC_BLOCK(inode,
 705                         alloc_count > block_count ? block_count : alloc_count))
 706                         alloc_count = 0;
 707                 else if (alloc_count > block_count) {
 708                         alloc_count = block_count;
 709                         eloc.logicalBlockNum += alloc_count;
 710                         elen -= (alloc_count << sb->s_blocksize_bits);
 711                         udf_write_aext(table, &epos, eloc,
 712                                         (etype << 30) | elen, 1);
 713                 } else
 714                         udf_delete_aext(table, epos, eloc,
 715                                         (etype << 30) | elen);
 716         } else {
 717                 alloc_count = 0;
 718         }
 719
 720         brelse(epos.bh);
 721
 722         if (alloc_count && sbi->s_lvid_bh) {
 723                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 724                 lvid->freeSpaceTable[partition] =
 725                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - alloc_count);
 726                 mark_buffer_dirty(sbi->s_lvid_bh);
 727                 sb->s_dirt = 1;
 728         }
 729         mutex_unlock(&sbi->s_alloc_mutex);
 730         return alloc_count;
 731 }
 732
 733 static int udf_table_new_block(struct super_block *sb,
 734                                struct inode *inode,
 735                                struct inode *table, uint16_t partition,
 736                                uint32_t goal, int *err)
 737 {
 738         struct udf_sb_info *sbi = UDF_SB(sb);
 739         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 740         uint32_t newblock = 0, adsize;
 741         uint32_t elen, goal_elen = 0;
 742         kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 743         struct extent_position epos, goal_epos;
 744         int8_t etype;
 745
 746         *err = -ENOSPC;
 747
 748         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 749                 adsize = sizeof(short_ad);
 750         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 751                 adsize = sizeof(long_ad);
 752         else
 753                 return newblock;
 754
 755         mutex_lock(&sbi->s_alloc_mutex);
 756         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 757                 goal = 0;
 758
 759         /* We search for the closest matching block to goal. If we find
 760            a exact hit, we stop. Otherwise we keep going till we run out
 761            of extents. We store the buffer_head, bloc, and extoffset
 762            of the current closest match and use that when we are done.
 763          */
 764         epos.offset = sizeof(struct unallocSpaceEntry);
 765         epos.block = UDF_I_LOCATION(table);
 766         epos.bh = goal_epos.bh = NULL;
 767
 768         while (spread &&
 769                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 770                 if (goal >= eloc.logicalBlockNum) {
 771                         if (goal < eloc.logicalBlockNum +
 772                                         (elen >> sb->s_blocksize_bits))
 773                                 nspread = 0;
 774                         else
 775                                 nspread = goal - eloc.logicalBlockNum -
 776                                         (elen >> sb->s_blocksize_bits);
 777                 } else {
 778                         nspread = eloc.logicalBlockNum - goal;
 779                 }
 780
 781                 if (nspread < spread) {
 782                         spread = nspread;
 783                         if (goal_epos.bh != epos.bh) {
 784                                 brelse(goal_epos.bh);
 785                                 goal_epos.bh = epos.bh;
 786                                 get_bh(goal_epos.bh);
 787                         }
 788                         goal_epos.block = epos.block;
 789                         goal_epos.offset = epos.offset - adsize;
 790                         goal_eloc = eloc;
 791                         goal_elen = (etype << 30) | elen;
 792                 }
 793         }
 794
 795         brelse(epos.bh);
 796
 797         if (spread == 0xFFFFFFFF) {
 798                 brelse(goal_epos.bh);
 799                 mutex_unlock(&sbi->s_alloc_mutex);
 800                 return 0;
 801         }
 802
 803         /* Only allocate blocks from the beginning of the extent.
 804            That way, we only delete (empty) extents, never have to insert an
 805            extent because of splitting */
 806         /* This works, but very poorly.... */
 807
 808         newblock = goal_eloc.logicalBlockNum;
 809         goal_eloc.logicalBlockNum++;
 810         goal_elen -= sb->s_blocksize;
 811
 812         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 813                 brelse(goal_epos.bh);
 814                 mutex_unlock(&sbi->s_alloc_mutex);
 815                 *err = -EDQUOT;
 816                 return 0;
 817         }
 818
 819         if (goal_elen)
 820                 udf_write_aext(table, &goal_epos, goal_eloc, goal_elen, 1);
 821         else
 822                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 823         brelse(goal_epos.bh);
 824
 825         if (sbi->s_lvid_bh) {
 826                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 827                 lvid->freeSpaceTable[partition] =
 828                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - 1);
 829                 mark_buffer_dirty(sbi->s_lvid_bh);
 830         }
 831
 832         sb->s_dirt = 1;
 833         mutex_unlock(&sbi->s_alloc_mutex);
 834         *err = 0;
 835         return newblock;
 836 }
 837
 838 inline void udf_free_blocks(struct super_block *sb,
 839                             struct inode *inode,
 840                             kernel_lb_addr bloc, uint32_t offset,
 841                             uint32_t count)
 842 {
 843         uint16_t partition = bloc.partitionReferenceNum;
 844         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 845
 846         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 847                 return udf_bitmap_free_blocks(sb, inode,
 848                                               map->s_uspace.s_bitmap,
 849                                               bloc, offset, count);
 850         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 851                 return udf_table_free_blocks(sb, inode,
 852                                              map->s_uspace.s_table,
 853                                              bloc, offset, count);
 854         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 855                 return udf_bitmap_free_blocks(sb, inode,
 856                                               map->s_fspace.s_bitmap,
 857                                               bloc, offset, count);
 858         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 859                 return udf_table_free_blocks(sb, inode,
 860                                              map->s_fspace.s_table,
 861                                              bloc, offset, count);
 862         } else {
 863                 return;
 864         }
 865 }
 866
 867 inline int udf_prealloc_blocks(struct super_block *sb,
 868                                struct inode *inode,
 869                                uint16_t partition, uint32_t first_block,
 870                                uint32_t block_count)
 871 {
 872         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 873
 874         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 875                 return udf_bitmap_prealloc_blocks(sb, inode,
 876                                                   map->s_uspace.s_bitmap,
 877                                                   partition, first_block,
 878                                                   block_count);
 879         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 880                 return udf_table_prealloc_blocks(sb, inode,
 881                                                  map->s_uspace.s_table,
 882                                                  partition, first_block,
 883                                                  block_count);
 884         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 885                 return udf_bitmap_prealloc_blocks(sb, inode,
 886                                                   map->s_fspace.s_bitmap,
 887                                                   partition, first_block,
 888                                                   block_count);
 889         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 890                 return udf_table_prealloc_blocks(sb, inode,
 891                                                  map->s_fspace.s_table,
 892                                                  partition, first_block,
 893                                                  block_count);
 894         else
 895                 return 0;
 896 }
 897
 898 inline int udf_new_block(struct super_block *sb,
 899                          struct inode *inode,
 900                          uint16_t partition, uint32_t goal, int *err)
 901 {
 902         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 903
 904         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 905                 return udf_bitmap_new_block(sb, inode,
 906                                            map->s_uspace.s_bitmap,
 907                                            partition, goal, err);
 908         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 909                 return udf_table_new_block(sb, inode,
 910                                            map->s_uspace.s_table,
 911                                            partition, goal, err);
 912         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 913                 return udf_bitmap_new_block(sb, inode,
 914                                             map->s_fspace.s_bitmap,
 915                                             partition, goal, err);
 916         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 917                 return udf_table_new_block(sb, inode,
 918                                            map->s_fspace.s_table,
 919                                            partition, goal, err);
 920         else {
 921                 *err = -EIO;
 922                 return 0;
 923         }
 924 }