fs/udf/balloc.c

   1 /*
   2  * balloc.c
   3  *
   4  * PURPOSE
   5  *      Block allocation handling routines for the OSTA-UDF(tm) filesystem.
   6  *
   7  * COPYRIGHT
   8  *      This file is distributed under the terms of the GNU General Public
   9  *      License (GPL). Copies of the GPL can be obtained from:
  10  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
  11  *      Each contributing author retains all rights to their own work.
  12  *
  13  *  (C) 1999-2001 Ben Fennema
  14  *  (C) 1999 Stelias Computing Inc
  15  *
  16  * HISTORY
  17  *
  18  *  02/24/99 blf  Created.
  19  *
  20  */
  21
  22 #include "udfdecl.h"
  23
  24 #include <linux/quotaops.h>
  25 #include <linux/buffer_head.h>
  26 #include <linux/bitops.h>
  27
  28 #include "udf_i.h"
  29 #include "udf_sb.h"
  30
  31 #define udf_clear_bit(nr,addr) ext2_clear_bit(nr,addr)
  32 #define udf_set_bit(nr,addr) ext2_set_bit(nr,addr)
  33 #define udf_test_bit(nr, addr) ext2_test_bit(nr, addr)
  34 #define udf_find_first_one_bit(addr, size) find_first_one_bit(addr, size)
  35 #define udf_find_next_one_bit(addr, size, offset) find_next_one_bit(addr, size, offset)
  36
  37 #define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x)
  38 #define leNUM_to_cpup(x,y) xleNUM_to_cpup(x,y)
  39 #define xleNUM_to_cpup(x,y) (le ## x ## _to_cpup(y))
  40 #define uintBPL_t uint(BITS_PER_LONG)
  41 #define uint(x) xuint(x)
  42 #define xuint(x) __le ## x
  43
  44 static inline int find_next_one_bit(void *addr, int size, int offset)
  45 {
  46         uintBPL_t *p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG);
  47         int result = offset & ~(BITS_PER_LONG - 1);
  48         unsigned long tmp;
  49
  50         if (offset >= size)
  51                 return size;
  52         size -= result;
  53         offset &= (BITS_PER_LONG - 1);
  54         if (offset) {
  55                 tmp = leBPL_to_cpup(p++);
  56                 tmp &= ~0UL << offset;
  57                 if (size < BITS_PER_LONG)
  58                         goto found_first;
  59                 if (tmp)
  60                         goto found_middle;
  61                 size -= BITS_PER_LONG;
  62                 result += BITS_PER_LONG;
  63         }
  64         while (size & ~(BITS_PER_LONG - 1)) {
  65                 if ((tmp = leBPL_to_cpup(p++)))
  66                         goto found_middle;
  67                 result += BITS_PER_LONG;
  68                 size -= BITS_PER_LONG;
  69         }
  70         if (!size)
  71                 return result;
  72         tmp = leBPL_to_cpup(p);
  73 found_first:
  74         tmp &= ~0UL >> (BITS_PER_LONG - size);
  75 found_middle:
  76         return result + ffz(~tmp);
  77 }
  78
  79 #define find_first_one_bit(addr, size)\
  80         find_next_one_bit((addr), (size), 0)
  81
  82 static int read_block_bitmap(struct super_block *sb,
  83                              struct udf_bitmap *bitmap, unsigned int block,
  84                              unsigned long bitmap_nr)
  85 {
  86         struct buffer_head *bh = NULL;
  87         int retval = 0;
  88         kernel_lb_addr loc;
  89
  90         loc.logicalBlockNum = bitmap->s_extPosition;
  91         loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
  92
  93         bh = udf_tread(sb, udf_get_lb_pblock(sb, loc, block));
  94         if (!bh) {
  95                 retval = -EIO;
  96         }
  97         bitmap->s_block_bitmap[bitmap_nr] = bh;
  98         return retval;
  99 }
 100
 101 static int __load_block_bitmap(struct super_block *sb,
 102                                struct udf_bitmap *bitmap,
 103                                unsigned int block_group)
 104 {
 105         int retval = 0;
 106         int nr_groups = bitmap->s_nr_groups;
 107
 108         if (block_group >= nr_groups) {
 109                 udf_debug("block_group (%d) > nr_groups (%d)\n", block_group,
 110                           nr_groups);
 111         }
 112
 113         if (bitmap->s_block_bitmap[block_group]) {
 114                 return block_group;
 115         } else {
 116                 retval = read_block_bitmap(sb, bitmap, block_group,
 117                                            block_group);
 118                 if (retval < 0)
 119                         return retval;
 120                 return block_group;
 121         }
 122 }
 123
 124 static inline int load_block_bitmap(struct super_block *sb,
 125                                     struct udf_bitmap *bitmap,
 126                                     unsigned int block_group)
 127 {
 128         int slot;
 129
 130         slot = __load_block_bitmap(sb, bitmap, block_group);
 131
 132         if (slot < 0)
 133                 return slot;
 134
 135         if (!bitmap->s_block_bitmap[slot])
 136                 return -EIO;
 137
 138         return slot;
 139 }
 140
 141 static void udf_bitmap_free_blocks(struct super_block *sb,
 142                                    struct inode *inode,
 143                                    struct udf_bitmap *bitmap,
 144                                    kernel_lb_addr bloc, uint32_t offset,
 145                                    uint32_t count)
 146 {
 147         struct udf_sb_info *sbi = UDF_SB(sb);
 148         struct buffer_head *bh = NULL;
 149         unsigned long block;
 150         unsigned long block_group;
 151         unsigned long bit;
 152         unsigned long i;
 153         int bitmap_nr;
 154         unsigned long overflow;
 155
 156         mutex_lock(&sbi->s_alloc_mutex);
 157         if (bloc.logicalBlockNum < 0 ||
 158             (bloc.logicalBlockNum + count) > sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
 159                 udf_debug("%d < %d || %d + %d > %d\n",
 160                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 161                           sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len);
 162                 goto error_return;
 163         }
 164
 165         block = bloc.logicalBlockNum + offset + (sizeof(struct spaceBitmapDesc) << 3);
 166
 167 do_more:
 168         overflow = 0;
 169         block_group = block >> (sb->s_blocksize_bits + 3);
 170         bit = block % (sb->s_blocksize << 3);
 171
 172         /*
 173          * Check to see if we are freeing blocks across a group boundary.
 174          */
 175         if (bit + count > (sb->s_blocksize << 3)) {
 176                 overflow = bit + count - (sb->s_blocksize << 3);
 177                 count -= overflow;
 178         }
 179         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 180         if (bitmap_nr < 0)
 181                 goto error_return;
 182
 183         bh = bitmap->s_block_bitmap[bitmap_nr];
 184         for (i = 0; i < count; i++) {
 185                 if (udf_set_bit(bit + i, bh->b_data)) {
 186                         udf_debug("bit %ld already set\n", bit + i);
 187                         udf_debug("byte=%2x\n", ((char *)bh->b_data)[(bit + i) >> 3]);
 188                 } else {
 189                         if (inode)
 190                                 DQUOT_FREE_BLOCK(inode, 1);
 191                         if (sbi->s_lvid_bh) {
 192                                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 193                                 lvid->freeSpaceTable[sbi->s_partition] =
 194                                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[sbi->s_partition]) + 1);
 195                         }
 196                 }
 197         }
 198         mark_buffer_dirty(bh);
 199         if (overflow) {
 200                 block += count;
 201                 count = overflow;
 202                 goto do_more;
 203         }
 204 error_return:
 205         sb->s_dirt = 1;
 206         if (sbi->s_lvid_bh)
 207                 mark_buffer_dirty(sbi->s_lvid_bh);
 208         mutex_unlock(&sbi->s_alloc_mutex);
 209         return;
 210 }
 211
 212 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 213                                       struct inode *inode,
 214                                       struct udf_bitmap *bitmap,
 215                                       uint16_t partition, uint32_t first_block,
 216                                       uint32_t block_count)
 217 {
 218         struct udf_sb_info *sbi = UDF_SB(sb);
 219         int alloc_count = 0;
 220         int bit, block, block_group, group_start;
 221         int nr_groups, bitmap_nr;
 222         struct buffer_head *bh;
 223         __u32 part_len;
 224
 225         mutex_lock(&sbi->s_alloc_mutex);
 226         part_len = sbi->s_partmaps[partition].s_partition_len;
 227         if (first_block < 0 || first_block >= part_len)
 228                 goto out;
 229
 230         if (first_block + block_count > part_len)
 231                 block_count = part_len - first_block;
 232
 233 repeat:
 234         nr_groups = (sbi->s_partmaps[partition].s_partition_len +
 235                      (sizeof(struct spaceBitmapDesc) << 3) +
 236                      (sb->s_blocksize * 8) - 1) / (sb->s_blocksize * 8);
 237         block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 238         block_group = block >> (sb->s_blocksize_bits + 3);
 239         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 240
 241         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 242         if (bitmap_nr < 0)
 243                 goto out;
 244         bh = bitmap->s_block_bitmap[bitmap_nr];
 245
 246         bit = block % (sb->s_blocksize << 3);
 247
 248         while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 249                 if (!udf_test_bit(bit, bh->b_data)) {
 250                         goto out;
 251                 } else if (DQUOT_PREALLOC_BLOCK(inode, 1)) {
 252                         goto out;
 253                 } else if (!udf_clear_bit(bit, bh->b_data)) {
 254                         udf_debug("bit already cleared for block %d\n", bit);
 255                         DQUOT_FREE_BLOCK(inode, 1);
 256                         goto out;
 257                 }
 258                 block_count--;
 259                 alloc_count++;
 260                 bit++;
 261                 block++;
 262         }
 263         mark_buffer_dirty(bh);
 264         if (block_count > 0)
 265                 goto repeat;
 266 out:
 267         if (sbi->s_lvid_bh) {
 268                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 269                 lvid->freeSpaceTable[partition] =
 270                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - alloc_count);
 271                 mark_buffer_dirty(sbi->s_lvid_bh);
 272         }
 273         sb->s_dirt = 1;
 274         mutex_unlock(&sbi->s_alloc_mutex);
 275         return alloc_count;
 276 }
 277
 278 static int udf_bitmap_new_block(struct super_block *sb,
 279                                 struct inode *inode,
 280                                 struct udf_bitmap *bitmap, uint16_t partition,
 281                                 uint32_t goal, int *err)
 282 {
 283         struct udf_sb_info *sbi = UDF_SB(sb);
 284         int newbit, bit = 0, block, block_group, group_start;
 285         int end_goal, nr_groups, bitmap_nr, i;
 286         struct buffer_head *bh = NULL;
 287         char *ptr;
 288         int newblock = 0;
 289
 290         *err = -ENOSPC;
 291         mutex_lock(&sbi->s_alloc_mutex);
 292
 293 repeat:
 294         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 295                 goal = 0;
 296
 297         nr_groups = bitmap->s_nr_groups;
 298         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 299         block_group = block >> (sb->s_blocksize_bits + 3);
 300         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 301
 302         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 303         if (bitmap_nr < 0)
 304                 goto error_return;
 305         bh = bitmap->s_block_bitmap[bitmap_nr];
 306         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 307                       sb->s_blocksize - group_start);
 308
 309         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 310                 bit = block % (sb->s_blocksize << 3);
 311                 if (udf_test_bit(bit, bh->b_data))
 312                         goto got_block;
 313
 314                 end_goal = (bit + 63) & ~63;
 315                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 316                 if (bit < end_goal)
 317                         goto got_block;
 318
 319                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF, sb->s_blocksize - ((bit + 7) >> 3));
 320                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 321                 if (newbit < sb->s_blocksize << 3) {
 322                         bit = newbit;
 323                         goto search_back;
 324                 }
 325
 326                 newbit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, bit);
 327                 if (newbit < sb->s_blocksize << 3) {
 328                         bit = newbit;
 329                         goto got_block;
 330                 }
 331         }
 332
 333         for (i = 0; i < (nr_groups * 2); i++) {
 334                 block_group++;
 335                 if (block_group >= nr_groups)
 336                         block_group = 0;
 337                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 338
 339                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 340                 if (bitmap_nr < 0)
 341                         goto error_return;
 342                 bh = bitmap->s_block_bitmap[bitmap_nr];
 343                 if (i < nr_groups) {
 344                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 345                                       sb->s_blocksize - group_start);
 346                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 347                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 348                                 break;
 349                         }
 350                 } else {
 351                         bit = udf_find_next_one_bit((char *)bh->b_data,
 352                                                     sb->s_blocksize << 3,
 353                                                     group_start << 3);
 354                         if (bit < sb->s_blocksize << 3)
 355                                 break;
 356                 }
 357         }
 358         if (i >= (nr_groups * 2)) {
 359                 mutex_unlock(&sbi->s_alloc_mutex);
 360                 return newblock;
 361         }
 362         if (bit < sb->s_blocksize << 3)
 363                 goto search_back;
 364         else
 365                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, group_start << 3);
 366         if (bit >= sb->s_blocksize << 3) {
 367                 mutex_unlock(&sbi->s_alloc_mutex);
 368                 return 0;
 369         }
 370
 371 search_back:
 372         for (i = 0; i < 7 && bit > (group_start << 3) && udf_test_bit(bit - 1, bh->b_data); i++, bit--)
 373                 ; /* empty loop */
 374
 375 got_block:
 376
 377         /*
 378          * Check quota for allocation of this block.
 379          */
 380         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 381                 mutex_unlock(&sbi->s_alloc_mutex);
 382                 *err = -EDQUOT;
 383                 return 0;
 384         }
 385
 386         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 387                 (sizeof(struct spaceBitmapDesc) << 3);
 388
 389         if (!udf_clear_bit(bit, bh->b_data)) {
 390                 udf_debug("bit already cleared for block %d\n", bit);
 391                 goto repeat;
 392         }
 393
 394         mark_buffer_dirty(bh);
 395
 396         if (sbi->s_lvid_bh) {
 397                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 398                 lvid->freeSpaceTable[partition] =
 399                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - 1);
 400                 mark_buffer_dirty(sbi->s_lvid_bh);
 401         }
 402         sb->s_dirt = 1;
 403         mutex_unlock(&sbi->s_alloc_mutex);
 404         *err = 0;
 405         return newblock;
 406
 407 error_return:
 408         *err = -EIO;
 409         mutex_unlock(&sbi->s_alloc_mutex);
 410         return 0;
 411 }
 412
 413 static void udf_table_free_blocks(struct super_block *sb,
 414                                   struct inode *inode,
 415                                   struct inode *table,
 416                                   kernel_lb_addr bloc, uint32_t offset,
 417                                   uint32_t count)
 418 {
 419         struct udf_sb_info *sbi = UDF_SB(sb);
 420         uint32_t start, end;
 421         uint32_t elen;
 422         kernel_lb_addr eloc;
 423         struct extent_position oepos, epos;
 424         int8_t etype;
 425         int i;
 426
 427         mutex_lock(&sbi->s_alloc_mutex);
 428         if (bloc.logicalBlockNum < 0 ||
 429             (bloc.logicalBlockNum + count) > sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
 430                 udf_debug("%d < %d || %d + %d > %d\n",
 431                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 432                           sbi->s_partmaps[bloc.partitionReferenceNum]->s_partition_len);
 433                 goto error_return;
 434         }
 435
 436         /* We do this up front - There are some error conditions that could occure,
 437            but.. oh well */
 438         if (inode)
 439                 DQUOT_FREE_BLOCK(inode, count);
 440         if (sbi->s_lvid_bh) {
 441                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 442                 lvid->freeSpaceTable[sbi->s_partition] =
 443                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[sbi->s_partition]) + count);
 444                 mark_buffer_dirty(sbi->s_lvid_bh);
 445         }
 446
 447         start = bloc.logicalBlockNum + offset;
 448         end = bloc.logicalBlockNum + offset + count - 1;
 449
 450         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 451         elen = 0;
 452         epos.block = oepos.block = UDF_I_LOCATION(table);
 453         epos.bh = oepos.bh = NULL;
 454
 455         while (count &&
 456                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 457                 if (((eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits)) == start)) {
 458                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits)) {
 459                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 460                                 start += ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 461                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 462                         } else {
 463                                 elen = (etype << 30) | (elen + (count << sb->s_blocksize_bits));
 464                                 start += count;
 465                                 count = 0;
 466                         }
 467                         udf_write_aext(table, &oepos, eloc, elen, 1);
 468                 } else if (eloc.logicalBlockNum == (end + 1)) {
 469                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits)) {
 470                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 471                                 end -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 472                                 eloc.logicalBlockNum -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 473                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 474                         } else {
 475                                 eloc.logicalBlockNum = start;
 476                                 elen = (etype << 30) | (elen + (count << sb->s_blocksize_bits));
 477                                 end -= count;
 478                                 count = 0;
 479                         }
 480                         udf_write_aext(table, &oepos, eloc, elen, 1);
 481                 }
 482
 483                 if (epos.bh != oepos.bh) {
 484                         i = -1;
 485                         oepos.block = epos.block;
 486                         brelse(oepos.bh);
 487                         get_bh(epos.bh);
 488                         oepos.bh = epos.bh;
 489                         oepos.offset = 0;
 490                 } else {
 491                         oepos.offset = epos.offset;
 492                 }
 493         }
 494
 495         if (count) {
 496                 /*
 497                  * NOTE: we CANNOT use udf_add_aext here, as it can try to allocate
 498                  * a new block, and since we hold the super block lock already
 499                  * very bad things would happen :)
 500                  *
 501                  * We copy the behavior of udf_add_aext, but instead of
 502                  * trying to allocate a new block close to the existing one,
 503                  * we just steal a block from the extent we are trying to add.
 504                  *
 505                  * It would be nice if the blocks were close together, but it
 506                  * isn't required.
 507                  */
 508
 509                 int adsize;
 510                 short_ad *sad = NULL;
 511                 long_ad *lad = NULL;
 512                 struct allocExtDesc *aed;
 513
 514                 eloc.logicalBlockNum = start;
 515                 elen = EXT_RECORDED_ALLOCATED |
 516                         (count << sb->s_blocksize_bits);
 517
 518                 if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT) {
 519                         adsize = sizeof(short_ad);
 520                 } else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG) {
 521                         adsize = sizeof(long_ad);
 522                 } else {
 523                         brelse(oepos.bh);
 524                         brelse(epos.bh);
 525                         goto error_return;
 526                 }
 527
 528                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 529                         char *sptr, *dptr;
 530                         int loffset;
 531
 532                         brelse(oepos.bh);
 533                         oepos = epos;
 534
 535                         /* Steal a block from the extent being free'd */
 536                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 537                         eloc.logicalBlockNum++;
 538                         elen -= sb->s_blocksize;
 539
 540                         if (!(epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, epos.block, 0)))) {
 541                                 brelse(oepos.bh);
 542                                 goto error_return;
 543                         }
 544                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 545                         aed->previousAllocExtLocation = cpu_to_le32(oepos.block.logicalBlockNum);
 546                         if (epos.offset + adsize > sb->s_blocksize) {
 547                                 loffset = epos.offset;
 548                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 549                                 sptr = UDF_I_DATA(table) + epos.offset - adsize;
 550                                 dptr = epos.bh->b_data + sizeof(struct allocExtDesc);
 551                                 memcpy(dptr, sptr, adsize);
 552                                 epos.offset = sizeof(struct allocExtDesc) + adsize;
 553                         } else {
 554                                 loffset = epos.offset + adsize;
 555                                 aed->lengthAllocDescs = cpu_to_le32(0);
 556                                 if (oepos.bh) {
 557                                         sptr = oepos.bh->b_data + epos.offset;
 558                                         aed = (struct allocExtDesc *)oepos.bh->b_data;
 559                                         aed->lengthAllocDescs =
 560                                                 cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 561                                 } else {
 562                                         sptr = UDF_I_DATA(table) + epos.offset;
 563                                         UDF_I_LENALLOC(table) += adsize;
 564                                         mark_inode_dirty(table);
 565                                 }
 566                                 epos.offset = sizeof(struct allocExtDesc);
 567                         }
 568                         if (sbi->s_udfrev >= 0x0200)
 569                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 3, 1,
 570                                             epos.block.logicalBlockNum, sizeof(tag));
 571                         else
 572                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 2, 1,
 573                                             epos.block.logicalBlockNum, sizeof(tag));
 574
 575                         switch (UDF_I_ALLOCTYPE(table)) {
 576                                 case ICBTAG_FLAG_AD_SHORT:
 577                                         sad = (short_ad *)sptr;
 578                                         sad->extLength = cpu_to_le32(
 579                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 580                                                 sb->s_blocksize);
 581                                         sad->extPosition = cpu_to_le32(epos.block.logicalBlockNum);
 582                                         break;
 583                                 case ICBTAG_FLAG_AD_LONG:
 584                                         lad = (long_ad *)sptr;
 585                                         lad->extLength = cpu_to_le32(
 586                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 587                                                 sb->s_blocksize);
 588                                         lad->extLocation = cpu_to_lelb(epos.block);
 589                                         break;
 590                         }
 591                         if (oepos.bh) {
 592                                 udf_update_tag(oepos.bh->b_data, loffset);
 593                                 mark_buffer_dirty(oepos.bh);
 594                         } else {
 595                                 mark_inode_dirty(table);
 596                         }
 597                 }
 598
 599                 if (elen) { /* It's possible that stealing the block emptied the extent */
 600                         udf_write_aext(table, &epos, eloc, elen, 1);
 601
 602                         if (!epos.bh) {
 603                                 UDF_I_LENALLOC(table) += adsize;
 604                                 mark_inode_dirty(table);
 605                         } else {
 606                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 607                                 aed->lengthAllocDescs =
 608                                         cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 609                                 udf_update_tag(epos.bh->b_data, epos.offset);
 610                                 mark_buffer_dirty(epos.bh);
 611                         }
 612                 }
 613         }
 614
 615         brelse(epos.bh);
 616         brelse(oepos.bh);
 617
 618 error_return:
 619         sb->s_dirt = 1;
 620         mutex_unlock(&sbi->s_alloc_mutex);
 621         return;
 622 }
 623
 624 static int udf_table_prealloc_blocks(struct super_block *sb,
 625                                      struct inode *inode,
 626                                      struct inode *table, uint16_t partition,
 627                                      uint32_t first_block, uint32_t block_count)
 628 {
 629         struct udf_sb_info *sbi = UDF_SB(sb);
 630         int alloc_count = 0;
 631         uint32_t elen, adsize;
 632         kernel_lb_addr eloc;
 633         struct extent_position epos;
 634         int8_t etype = -1;
 635
 636         if (first_block < 0 || first_block >= sbi->s_partmaps[partition].s_partition_len)
 637                 return 0;
 638
 639         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 640                 adsize = sizeof(short_ad);
 641         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 642                 adsize = sizeof(long_ad);
 643         else
 644                 return 0;
 645
 646         mutex_lock(&sbi->s_alloc_mutex);
 647         epos.offset = sizeof(struct unallocSpaceEntry);
 648         epos.block = UDF_I_LOCATION(table);
 649         epos.bh = NULL;
 650         eloc.logicalBlockNum = 0xFFFFFFFF;
 651
 652         while (first_block != eloc.logicalBlockNum &&
 653                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 654                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 655                           eloc.logicalBlockNum, elen, first_block);
 656                 ; /* empty loop body */
 657         }
 658
 659         if (first_block == eloc.logicalBlockNum) {
 660                 epos.offset -= adsize;
 661
 662                 alloc_count = (elen >> sb->s_blocksize_bits);
 663                 if (inode && DQUOT_PREALLOC_BLOCK(inode, alloc_count > block_count ? block_count : alloc_count)) {
 664                         alloc_count = 0;
 665                 } else if (alloc_count > block_count) {
 666                         alloc_count = block_count;
 667                         eloc.logicalBlockNum += alloc_count;
 668                         elen -= (alloc_count << sb->s_blocksize_bits);
 669                         udf_write_aext(table, &epos, eloc, (etype << 30) | elen, 1);
 670                 } else {
 671                         udf_delete_aext(table, epos, eloc, (etype << 30) | elen);
 672                 }
 673         } else {
 674                 alloc_count = 0;
 675         }
 676
 677         brelse(epos.bh);
 678
 679         if (alloc_count && sbi->s_lvid_bh) {
 680                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 681                 lvid->freeSpaceTable[partition] =
 682                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - alloc_count);
 683                 mark_buffer_dirty(sbi->s_lvid_bh);
 684                 sb->s_dirt = 1;
 685         }
 686         mutex_unlock(&sbi->s_alloc_mutex);
 687         return alloc_count;
 688 }
 689
 690 static int udf_table_new_block(struct super_block *sb,
 691                                struct inode *inode,
 692                                struct inode *table, uint16_t partition,
 693                                uint32_t goal, int *err)
 694 {
 695         struct udf_sb_info *sbi = UDF_SB(sb);
 696         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 697         uint32_t newblock = 0, adsize;
 698         uint32_t elen, goal_elen = 0;
 699         kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 700         struct extent_position epos, goal_epos;
 701         int8_t etype;
 702
 703         *err = -ENOSPC;
 704
 705         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 706                 adsize = sizeof(short_ad);
 707         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 708                 adsize = sizeof(long_ad);
 709         else
 710                 return newblock;
 711
 712         mutex_lock(&sbi->s_alloc_mutex);
 713         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 714                 goal = 0;
 715
 716         /* We search for the closest matching block to goal. If we find a exact hit,
 717            we stop. Otherwise we keep going till we run out of extents.
 718            We store the buffer_head, bloc, and extoffset of the current closest
 719            match and use that when we are done.
 720          */
 721         epos.offset = sizeof(struct unallocSpaceEntry);
 722         epos.block = UDF_I_LOCATION(table);
 723         epos.bh = goal_epos.bh = NULL;
 724
 725         while (spread &&
 726                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 727                 if (goal >= eloc.logicalBlockNum) {
 728                         if (goal < eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits))
 729                                 nspread = 0;
 730                         else
 731                                 nspread = goal - eloc.logicalBlockNum -
 732                                         (elen >> sb->s_blocksize_bits);
 733                 } else {
 734                         nspread = eloc.logicalBlockNum - goal;
 735                 }
 736
 737                 if (nspread < spread) {
 738                         spread = nspread;
 739                         if (goal_epos.bh != epos.bh) {
 740                                 brelse(goal_epos.bh);
 741                                 goal_epos.bh = epos.bh;
 742                                 get_bh(goal_epos.bh);
 743                         }
 744                         goal_epos.block = epos.block;
 745                         goal_epos.offset = epos.offset - adsize;
 746                         goal_eloc = eloc;
 747                         goal_elen = (etype << 30) | elen;
 748                 }
 749         }
 750
 751         brelse(epos.bh);
 752
 753         if (spread == 0xFFFFFFFF) {
 754                 brelse(goal_epos.bh);
 755                 mutex_unlock(&sbi->s_alloc_mutex);
 756                 return 0;
 757         }
 758
 759         /* Only allocate blocks from the beginning of the extent.
 760            That way, we only delete (empty) extents, never have to insert an
 761            extent because of splitting */
 762         /* This works, but very poorly.... */
 763
 764         newblock = goal_eloc.logicalBlockNum;
 765         goal_eloc.logicalBlockNum++;
 766         goal_elen -= sb->s_blocksize;
 767
 768         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 769                 brelse(goal_epos.bh);
 770                 mutex_unlock(&sbi->s_alloc_mutex);
 771                 *err = -EDQUOT;
 772                 return 0;
 773         }
 774
 775         if (goal_elen)
 776                 udf_write_aext(table, &goal_epos, goal_eloc, goal_elen, 1);
 777         else
 778                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 779         brelse(goal_epos.bh);
 780
 781         if (sbi->s_lvid_bh) {
 782                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 783                 lvid->freeSpaceTable[partition] =
 784                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - 1);
 785                 mark_buffer_dirty(sbi->s_lvid_bh);
 786         }
 787
 788         sb->s_dirt = 1;
 789         mutex_unlock(&sbi->s_alloc_mutex);
 790         *err = 0;
 791         return newblock;
 792 }
 793
 794 inline void udf_free_blocks(struct super_block *sb,
 795                             struct inode *inode,
 796                             kernel_lb_addr bloc, uint32_t offset,
 797                             uint32_t count)
 798 {
 799         uint16_t partition = bloc.partitionReferenceNum;
 800         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 801
 802         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 803                 return udf_bitmap_free_blocks(sb, inode,
 804                                               map->s_uspace.s_bitmap,
 805                                               bloc, offset, count);
 806         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 807                 return udf_table_free_blocks(sb, inode,
 808                                              map->s_uspace.s_table,
 809                                              bloc, offset, count);
 810         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 811                 return udf_bitmap_free_blocks(sb, inode,
 812                                               map->s_fspace.s_bitmap,
 813                                               bloc, offset, count);
 814         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 815                 return udf_table_free_blocks(sb, inode,
 816                                              map->s_fspace.s_table,
 817                                              bloc, offset, count);
 818         } else {
 819                 return;
 820         }
 821 }
 822
 823 inline int udf_prealloc_blocks(struct super_block *sb,
 824                                struct inode *inode,
 825                                uint16_t partition, uint32_t first_block,
 826                                uint32_t block_count)
 827 {
 828         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 829
 830         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 831                 return udf_bitmap_prealloc_blocks(sb, inode,
 832                                                   map->s_uspace.s_bitmap,
 833                                                   partition, first_block, block_count);
 834         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 835                 return udf_table_prealloc_blocks(sb, inode,
 836                                                  map->s_uspace.s_table,
 837                                                  partition, first_block, block_count);
 838         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 839                 return udf_bitmap_prealloc_blocks(sb, inode,
 840                                                   map->s_fspace.s_bitmap,
 841                                                   partition, first_block, block_count);
 842         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 843                 return udf_table_prealloc_blocks(sb, inode,
 844                                                  map->s_fspace.s_table,
 845                                                  partition, first_block, block_count);
 846         } else {
 847                 return 0;
 848         }
 849 }
 850
 851 inline int udf_new_block(struct super_block *sb,
 852                          struct inode *inode,
 853                          uint16_t partition, uint32_t goal, int *err)
 854 {
 855         int ret;
 856         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 857
 858         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 859                 ret = udf_bitmap_new_block(sb, inode,
 860                                            map->s_uspace.s_bitmap,
 861                                            partition, goal, err);
 862                 return ret;
 863         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 864                 return udf_table_new_block(sb, inode,
 865                                            map->s_uspace.s_table,
 866                                            partition, goal, err);
 867         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 868                 return udf_bitmap_new_block(sb, inode,
 869                                             map->s_fspace.s_bitmap,
 870                                             partition, goal, err);
 871         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 872                 return udf_table_new_block(sb, inode,
 873                                            map->s_fspace.s_table,
 874                                            partition, goal, err);
 875         } else {
 876                 *err = -EIO;
 877                 return 0;
 878         }
 879 }