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 = udf_compute_nr_groups(sb, partition);
 235         block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 236         block_group = block >> (sb->s_blocksize_bits + 3);
 237         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 238
 239         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 240         if (bitmap_nr < 0)
 241                 goto out;
 242         bh = bitmap->s_block_bitmap[bitmap_nr];
 243
 244         bit = block % (sb->s_blocksize << 3);
 245
 246         while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 247                 if (!udf_test_bit(bit, bh->b_data)) {
 248                         goto out;
 249                 } else if (DQUOT_PREALLOC_BLOCK(inode, 1)) {
 250                         goto out;
 251                 } else if (!udf_clear_bit(bit, bh->b_data)) {
 252                         udf_debug("bit already cleared for block %d\n", bit);
 253                         DQUOT_FREE_BLOCK(inode, 1);
 254                         goto out;
 255                 }
 256                 block_count--;
 257                 alloc_count++;
 258                 bit++;
 259                 block++;
 260         }
 261         mark_buffer_dirty(bh);
 262         if (block_count > 0)
 263                 goto repeat;
 264 out:
 265         if (sbi->s_lvid_bh) {
 266                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 267                 lvid->freeSpaceTable[partition] =
 268                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - alloc_count);
 269                 mark_buffer_dirty(sbi->s_lvid_bh);
 270         }
 271         sb->s_dirt = 1;
 272         mutex_unlock(&sbi->s_alloc_mutex);
 273         return alloc_count;
 274 }
 275
 276 static int udf_bitmap_new_block(struct super_block *sb,
 277                                 struct inode *inode,
 278                                 struct udf_bitmap *bitmap, uint16_t partition,
 279                                 uint32_t goal, int *err)
 280 {
 281         struct udf_sb_info *sbi = UDF_SB(sb);
 282         int newbit, bit = 0, block, block_group, group_start;
 283         int end_goal, nr_groups, bitmap_nr, i;
 284         struct buffer_head *bh = NULL;
 285         char *ptr;
 286         int newblock = 0;
 287
 288         *err = -ENOSPC;
 289         mutex_lock(&sbi->s_alloc_mutex);
 290
 291 repeat:
 292         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 293                 goal = 0;
 294
 295         nr_groups = bitmap->s_nr_groups;
 296         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 297         block_group = block >> (sb->s_blocksize_bits + 3);
 298         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 299
 300         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 301         if (bitmap_nr < 0)
 302                 goto error_return;
 303         bh = bitmap->s_block_bitmap[bitmap_nr];
 304         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 305                       sb->s_blocksize - group_start);
 306
 307         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 308                 bit = block % (sb->s_blocksize << 3);
 309                 if (udf_test_bit(bit, bh->b_data))
 310                         goto got_block;
 311
 312                 end_goal = (bit + 63) & ~63;
 313                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 314                 if (bit < end_goal)
 315                         goto got_block;
 316
 317                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF, sb->s_blocksize - ((bit + 7) >> 3));
 318                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 319                 if (newbit < sb->s_blocksize << 3) {
 320                         bit = newbit;
 321                         goto search_back;
 322                 }
 323
 324                 newbit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, bit);
 325                 if (newbit < sb->s_blocksize << 3) {
 326                         bit = newbit;
 327                         goto got_block;
 328                 }
 329         }
 330
 331         for (i = 0; i < (nr_groups * 2); i++) {
 332                 block_group++;
 333                 if (block_group >= nr_groups)
 334                         block_group = 0;
 335                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 336
 337                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 338                 if (bitmap_nr < 0)
 339                         goto error_return;
 340                 bh = bitmap->s_block_bitmap[bitmap_nr];
 341                 if (i < nr_groups) {
 342                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 343                                       sb->s_blocksize - group_start);
 344                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 345                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 346                                 break;
 347                         }
 348                 } else {
 349                         bit = udf_find_next_one_bit((char *)bh->b_data,
 350                                                     sb->s_blocksize << 3,
 351                                                     group_start << 3);
 352                         if (bit < sb->s_blocksize << 3)
 353                                 break;
 354                 }
 355         }
 356         if (i >= (nr_groups * 2)) {
 357                 mutex_unlock(&sbi->s_alloc_mutex);
 358                 return newblock;
 359         }
 360         if (bit < sb->s_blocksize << 3)
 361                 goto search_back;
 362         else
 363                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, group_start << 3);
 364         if (bit >= sb->s_blocksize << 3) {
 365                 mutex_unlock(&sbi->s_alloc_mutex);
 366                 return 0;
 367         }
 368
 369 search_back:
 370         for (i = 0; i < 7 && bit > (group_start << 3) && udf_test_bit(bit - 1, bh->b_data); i++, bit--)
 371                 ; /* empty loop */
 372
 373 got_block:
 374
 375         /*
 376          * Check quota for allocation of this block.
 377          */
 378         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 379                 mutex_unlock(&sbi->s_alloc_mutex);
 380                 *err = -EDQUOT;
 381                 return 0;
 382         }
 383
 384         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 385                 (sizeof(struct spaceBitmapDesc) << 3);
 386
 387         if (!udf_clear_bit(bit, bh->b_data)) {
 388                 udf_debug("bit already cleared for block %d\n", bit);
 389                 goto repeat;
 390         }
 391
 392         mark_buffer_dirty(bh);
 393
 394         if (sbi->s_lvid_bh) {
 395                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 396                 lvid->freeSpaceTable[partition] =
 397                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - 1);
 398                 mark_buffer_dirty(sbi->s_lvid_bh);
 399         }
 400         sb->s_dirt = 1;
 401         mutex_unlock(&sbi->s_alloc_mutex);
 402         *err = 0;
 403         return newblock;
 404
 405 error_return:
 406         *err = -EIO;
 407         mutex_unlock(&sbi->s_alloc_mutex);
 408         return 0;
 409 }
 410
 411 static void udf_table_free_blocks(struct super_block *sb,
 412                                   struct inode *inode,
 413                                   struct inode *table,
 414                                   kernel_lb_addr bloc, uint32_t offset,
 415                                   uint32_t count)
 416 {
 417         struct udf_sb_info *sbi = UDF_SB(sb);
 418         uint32_t start, end;
 419         uint32_t elen;
 420         kernel_lb_addr eloc;
 421         struct extent_position oepos, epos;
 422         int8_t etype;
 423         int i;
 424
 425         mutex_lock(&sbi->s_alloc_mutex);
 426         if (bloc.logicalBlockNum < 0 ||
 427             (bloc.logicalBlockNum + count) > sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
 428                 udf_debug("%d < %d || %d + %d > %d\n",
 429                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 430                           sbi->s_partmaps[bloc.partitionReferenceNum]->s_partition_len);
 431                 goto error_return;
 432         }
 433
 434         /* We do this up front - There are some error conditions that could occure,
 435            but.. oh well */
 436         if (inode)
 437                 DQUOT_FREE_BLOCK(inode, count);
 438         if (sbi->s_lvid_bh) {
 439                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 440                 lvid->freeSpaceTable[sbi->s_partition] =
 441                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[sbi->s_partition]) + count);
 442                 mark_buffer_dirty(sbi->s_lvid_bh);
 443         }
 444
 445         start = bloc.logicalBlockNum + offset;
 446         end = bloc.logicalBlockNum + offset + count - 1;
 447
 448         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 449         elen = 0;
 450         epos.block = oepos.block = UDF_I_LOCATION(table);
 451         epos.bh = oepos.bh = NULL;
 452
 453         while (count &&
 454                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 455                 if (((eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits)) == start)) {
 456                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits)) {
 457                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 458                                 start += ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 459                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 460                         } else {
 461                                 elen = (etype << 30) | (elen + (count << sb->s_blocksize_bits));
 462                                 start += count;
 463                                 count = 0;
 464                         }
 465                         udf_write_aext(table, &oepos, eloc, elen, 1);
 466                 } else if (eloc.logicalBlockNum == (end + 1)) {
 467                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits)) {
 468                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 469                                 end -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 470                                 eloc.logicalBlockNum -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 471                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 472                         } else {
 473                                 eloc.logicalBlockNum = start;
 474                                 elen = (etype << 30) | (elen + (count << sb->s_blocksize_bits));
 475                                 end -= count;
 476                                 count = 0;
 477                         }
 478                         udf_write_aext(table, &oepos, eloc, elen, 1);
 479                 }
 480
 481                 if (epos.bh != oepos.bh) {
 482                         i = -1;
 483                         oepos.block = epos.block;
 484                         brelse(oepos.bh);
 485                         get_bh(epos.bh);
 486                         oepos.bh = epos.bh;
 487                         oepos.offset = 0;
 488                 } else {
 489                         oepos.offset = epos.offset;
 490                 }
 491         }
 492
 493         if (count) {
 494                 /*
 495                  * NOTE: we CANNOT use udf_add_aext here, as it can try to allocate
 496                  * a new block, and since we hold the super block lock already
 497                  * very bad things would happen :)
 498                  *
 499                  * We copy the behavior of udf_add_aext, but instead of
 500                  * trying to allocate a new block close to the existing one,
 501                  * we just steal a block from the extent we are trying to add.
 502                  *
 503                  * It would be nice if the blocks were close together, but it
 504                  * isn't required.
 505                  */
 506
 507                 int adsize;
 508                 short_ad *sad = NULL;
 509                 long_ad *lad = NULL;
 510                 struct allocExtDesc *aed;
 511
 512                 eloc.logicalBlockNum = start;
 513                 elen = EXT_RECORDED_ALLOCATED |
 514                         (count << sb->s_blocksize_bits);
 515
 516                 if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT) {
 517                         adsize = sizeof(short_ad);
 518                 } else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG) {
 519                         adsize = sizeof(long_ad);
 520                 } else {
 521                         brelse(oepos.bh);
 522                         brelse(epos.bh);
 523                         goto error_return;
 524                 }
 525
 526                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 527                         char *sptr, *dptr;
 528                         int loffset;
 529
 530                         brelse(oepos.bh);
 531                         oepos = epos;
 532
 533                         /* Steal a block from the extent being free'd */
 534                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 535                         eloc.logicalBlockNum++;
 536                         elen -= sb->s_blocksize;
 537
 538                         if (!(epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, epos.block, 0)))) {
 539                                 brelse(oepos.bh);
 540                                 goto error_return;
 541                         }
 542                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 543                         aed->previousAllocExtLocation = cpu_to_le32(oepos.block.logicalBlockNum);
 544                         if (epos.offset + adsize > sb->s_blocksize) {
 545                                 loffset = epos.offset;
 546                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 547                                 sptr = UDF_I_DATA(table) + epos.offset - adsize;
 548                                 dptr = epos.bh->b_data + sizeof(struct allocExtDesc);
 549                                 memcpy(dptr, sptr, adsize);
 550                                 epos.offset = sizeof(struct allocExtDesc) + adsize;
 551                         } else {
 552                                 loffset = epos.offset + adsize;
 553                                 aed->lengthAllocDescs = cpu_to_le32(0);
 554                                 if (oepos.bh) {
 555                                         sptr = oepos.bh->b_data + epos.offset;
 556                                         aed = (struct allocExtDesc *)oepos.bh->b_data;
 557                                         aed->lengthAllocDescs =
 558                                                 cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 559                                 } else {
 560                                         sptr = UDF_I_DATA(table) + epos.offset;
 561                                         UDF_I_LENALLOC(table) += adsize;
 562                                         mark_inode_dirty(table);
 563                                 }
 564                                 epos.offset = sizeof(struct allocExtDesc);
 565                         }
 566                         if (sbi->s_udfrev >= 0x0200)
 567                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 3, 1,
 568                                             epos.block.logicalBlockNum, sizeof(tag));
 569                         else
 570                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 2, 1,
 571                                             epos.block.logicalBlockNum, sizeof(tag));
 572
 573                         switch (UDF_I_ALLOCTYPE(table)) {
 574                                 case ICBTAG_FLAG_AD_SHORT:
 575                                         sad = (short_ad *)sptr;
 576                                         sad->extLength = cpu_to_le32(
 577                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 578                                                 sb->s_blocksize);
 579                                         sad->extPosition = cpu_to_le32(epos.block.logicalBlockNum);
 580                                         break;
 581                                 case ICBTAG_FLAG_AD_LONG:
 582                                         lad = (long_ad *)sptr;
 583                                         lad->extLength = cpu_to_le32(
 584                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 585                                                 sb->s_blocksize);
 586                                         lad->extLocation = cpu_to_lelb(epos.block);
 587                                         break;
 588                         }
 589                         if (oepos.bh) {
 590                                 udf_update_tag(oepos.bh->b_data, loffset);
 591                                 mark_buffer_dirty(oepos.bh);
 592                         } else {
 593                                 mark_inode_dirty(table);
 594                         }
 595                 }
 596
 597                 if (elen) { /* It's possible that stealing the block emptied the extent */
 598                         udf_write_aext(table, &epos, eloc, elen, 1);
 599
 600                         if (!epos.bh) {
 601                                 UDF_I_LENALLOC(table) += adsize;
 602                                 mark_inode_dirty(table);
 603                         } else {
 604                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 605                                 aed->lengthAllocDescs =
 606                                         cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 607                                 udf_update_tag(epos.bh->b_data, epos.offset);
 608                                 mark_buffer_dirty(epos.bh);
 609                         }
 610                 }
 611         }
 612
 613         brelse(epos.bh);
 614         brelse(oepos.bh);
 615
 616 error_return:
 617         sb->s_dirt = 1;
 618         mutex_unlock(&sbi->s_alloc_mutex);
 619         return;
 620 }
 621
 622 static int udf_table_prealloc_blocks(struct super_block *sb,
 623                                      struct inode *inode,
 624                                      struct inode *table, uint16_t partition,
 625                                      uint32_t first_block, uint32_t block_count)
 626 {
 627         struct udf_sb_info *sbi = UDF_SB(sb);
 628         int alloc_count = 0;
 629         uint32_t elen, adsize;
 630         kernel_lb_addr eloc;
 631         struct extent_position epos;
 632         int8_t etype = -1;
 633
 634         if (first_block < 0 || first_block >= sbi->s_partmaps[partition].s_partition_len)
 635                 return 0;
 636
 637         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 638                 adsize = sizeof(short_ad);
 639         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 640                 adsize = sizeof(long_ad);
 641         else
 642                 return 0;
 643
 644         mutex_lock(&sbi->s_alloc_mutex);
 645         epos.offset = sizeof(struct unallocSpaceEntry);
 646         epos.block = UDF_I_LOCATION(table);
 647         epos.bh = NULL;
 648         eloc.logicalBlockNum = 0xFFFFFFFF;
 649
 650         while (first_block != eloc.logicalBlockNum &&
 651                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 652                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 653                           eloc.logicalBlockNum, elen, first_block);
 654                 ; /* empty loop body */
 655         }
 656
 657         if (first_block == eloc.logicalBlockNum) {
 658                 epos.offset -= adsize;
 659
 660                 alloc_count = (elen >> sb->s_blocksize_bits);
 661                 if (inode && DQUOT_PREALLOC_BLOCK(inode, alloc_count > block_count ? block_count : alloc_count)) {
 662                         alloc_count = 0;
 663                 } else if (alloc_count > block_count) {
 664                         alloc_count = block_count;
 665                         eloc.logicalBlockNum += alloc_count;
 666                         elen -= (alloc_count << sb->s_blocksize_bits);
 667                         udf_write_aext(table, &epos, eloc, (etype << 30) | elen, 1);
 668                 } else {
 669                         udf_delete_aext(table, epos, eloc, (etype << 30) | elen);
 670                 }
 671         } else {
 672                 alloc_count = 0;
 673         }
 674
 675         brelse(epos.bh);
 676
 677         if (alloc_count && sbi->s_lvid_bh) {
 678                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 679                 lvid->freeSpaceTable[partition] =
 680                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - alloc_count);
 681                 mark_buffer_dirty(sbi->s_lvid_bh);
 682                 sb->s_dirt = 1;
 683         }
 684         mutex_unlock(&sbi->s_alloc_mutex);
 685         return alloc_count;
 686 }
 687
 688 static int udf_table_new_block(struct super_block *sb,
 689                                struct inode *inode,
 690                                struct inode *table, uint16_t partition,
 691                                uint32_t goal, int *err)
 692 {
 693         struct udf_sb_info *sbi = UDF_SB(sb);
 694         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 695         uint32_t newblock = 0, adsize;
 696         uint32_t elen, goal_elen = 0;
 697         kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 698         struct extent_position epos, goal_epos;
 699         int8_t etype;
 700
 701         *err = -ENOSPC;
 702
 703         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 704                 adsize = sizeof(short_ad);
 705         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 706                 adsize = sizeof(long_ad);
 707         else
 708                 return newblock;
 709
 710         mutex_lock(&sbi->s_alloc_mutex);
 711         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 712                 goal = 0;
 713
 714         /* We search for the closest matching block to goal. If we find a exact hit,
 715            we stop. Otherwise we keep going till we run out of extents.
 716            We store the buffer_head, bloc, and extoffset of the current closest
 717            match and use that when we are done.
 718          */
 719         epos.offset = sizeof(struct unallocSpaceEntry);
 720         epos.block = UDF_I_LOCATION(table);
 721         epos.bh = goal_epos.bh = NULL;
 722
 723         while (spread &&
 724                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 725                 if (goal >= eloc.logicalBlockNum) {
 726                         if (goal < eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits))
 727                                 nspread = 0;
 728                         else
 729                                 nspread = goal - eloc.logicalBlockNum -
 730                                         (elen >> sb->s_blocksize_bits);
 731                 } else {
 732                         nspread = eloc.logicalBlockNum - goal;
 733                 }
 734
 735                 if (nspread < spread) {
 736                         spread = nspread;
 737                         if (goal_epos.bh != epos.bh) {
 738                                 brelse(goal_epos.bh);
 739                                 goal_epos.bh = epos.bh;
 740                                 get_bh(goal_epos.bh);
 741                         }
 742                         goal_epos.block = epos.block;
 743                         goal_epos.offset = epos.offset - adsize;
 744                         goal_eloc = eloc;
 745                         goal_elen = (etype << 30) | elen;
 746                 }
 747         }
 748
 749         brelse(epos.bh);
 750
 751         if (spread == 0xFFFFFFFF) {
 752                 brelse(goal_epos.bh);
 753                 mutex_unlock(&sbi->s_alloc_mutex);
 754                 return 0;
 755         }
 756
 757         /* Only allocate blocks from the beginning of the extent.
 758            That way, we only delete (empty) extents, never have to insert an
 759            extent because of splitting */
 760         /* This works, but very poorly.... */
 761
 762         newblock = goal_eloc.logicalBlockNum;
 763         goal_eloc.logicalBlockNum++;
 764         goal_elen -= sb->s_blocksize;
 765
 766         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 767                 brelse(goal_epos.bh);
 768                 mutex_unlock(&sbi->s_alloc_mutex);
 769                 *err = -EDQUOT;
 770                 return 0;
 771         }
 772
 773         if (goal_elen)
 774                 udf_write_aext(table, &goal_epos, goal_eloc, goal_elen, 1);
 775         else
 776                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 777         brelse(goal_epos.bh);
 778
 779         if (sbi->s_lvid_bh) {
 780                 struct logicalVolIntegrityDesc *lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 781                 lvid->freeSpaceTable[partition] =
 782                         cpu_to_le32(le32_to_cpu(lvid->freeSpaceTable[partition]) - 1);
 783                 mark_buffer_dirty(sbi->s_lvid_bh);
 784         }
 785
 786         sb->s_dirt = 1;
 787         mutex_unlock(&sbi->s_alloc_mutex);
 788         *err = 0;
 789         return newblock;
 790 }
 791
 792 inline void udf_free_blocks(struct super_block *sb,
 793                             struct inode *inode,
 794                             kernel_lb_addr bloc, uint32_t offset,
 795                             uint32_t count)
 796 {
 797         uint16_t partition = bloc.partitionReferenceNum;
 798         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 799
 800         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 801                 return udf_bitmap_free_blocks(sb, inode,
 802                                               map->s_uspace.s_bitmap,
 803                                               bloc, offset, count);
 804         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 805                 return udf_table_free_blocks(sb, inode,
 806                                              map->s_uspace.s_table,
 807                                              bloc, offset, count);
 808         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 809                 return udf_bitmap_free_blocks(sb, inode,
 810                                               map->s_fspace.s_bitmap,
 811                                               bloc, offset, count);
 812         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 813                 return udf_table_free_blocks(sb, inode,
 814                                              map->s_fspace.s_table,
 815                                              bloc, offset, count);
 816         } else {
 817                 return;
 818         }
 819 }
 820
 821 inline int udf_prealloc_blocks(struct super_block *sb,
 822                                struct inode *inode,
 823                                uint16_t partition, uint32_t first_block,
 824                                uint32_t block_count)
 825 {
 826         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 827
 828         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 829                 return udf_bitmap_prealloc_blocks(sb, inode,
 830                                                   map->s_uspace.s_bitmap,
 831                                                   partition, first_block, block_count);
 832         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 833                 return udf_table_prealloc_blocks(sb, inode,
 834                                                  map->s_uspace.s_table,
 835                                                  partition, first_block, block_count);
 836         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 837                 return udf_bitmap_prealloc_blocks(sb, inode,
 838                                                   map->s_fspace.s_bitmap,
 839                                                   partition, first_block, block_count);
 840         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 841                 return udf_table_prealloc_blocks(sb, inode,
 842                                                  map->s_fspace.s_table,
 843                                                  partition, first_block, block_count);
 844         } else {
 845                 return 0;
 846         }
 847 }
 848
 849 inline int udf_new_block(struct super_block *sb,
 850                          struct inode *inode,
 851                          uint16_t partition, uint32_t goal, int *err)
 852 {
 853         int ret;
 854         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 855
 856         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 857                 ret = udf_bitmap_new_block(sb, inode,
 858                                            map->s_uspace.s_bitmap,
 859                                            partition, goal, err);
 860                 return ret;
 861         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 862                 return udf_table_new_block(sb, inode,
 863                                            map->s_uspace.s_table,
 864                                            partition, goal, err);
 865         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 866                 return udf_bitmap_new_block(sb, inode,
 867                                             map->s_fspace.s_bitmap,
 868                                             partition, goal, err);
 869         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 870                 return udf_table_new_block(sb, inode,
 871                                            map->s_fspace.s_table,
 872                                            partition, goal, err);
 873         } else {
 874                 *err = -EIO;
 875                 return 0;
 876         }
 877 }