fs/udf/balloc.c

   1 /*
   2  * balloc.c
   3  *
   4  * PURPOSE
   5  *      Block allocation handling routines for the OSTA-UDF(tm) filesystem.
   6  *
   7  * COPYRIGHT
   8  *      This file is distributed under the terms of the GNU General Public
   9  *      License (GPL). Copies of the GPL can be obtained from:
  10  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
  11  *      Each contributing author retains all rights to their own work.
  12  *
  13  *  (C) 1999-2001 Ben Fennema
  14  *  (C) 1999 Stelias Computing Inc
  15  *
  16  * HISTORY
  17  *
  18  *  02/24/99 blf  Created.
  19  *
  20  */
  21
  22 #include "udfdecl.h"
  23
  24 #include <linux/quotaops.h>
  25 #include <linux/buffer_head.h>
  26 #include <linux/bitops.h>
  27
  28 #include "udf_i.h"
  29 #include "udf_sb.h"
  30
  31 #define udf_clear_bit(nr, addr) ext2_clear_bit(nr, addr)
  32 #define udf_set_bit(nr, addr) ext2_set_bit(nr, addr)
  33 #define udf_test_bit(nr, addr) ext2_test_bit(nr, addr)
  34 #define udf_find_first_one_bit(addr, size) find_first_one_bit(addr, size)
  35 #define udf_find_next_one_bit(addr, size, offset) \
  36                 find_next_one_bit(addr, size, offset)
  37
  38 #define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x)
  39 #define leNUM_to_cpup(x, y) xleNUM_to_cpup(x, y)
  40 #define xleNUM_to_cpup(x, y) (le ## x ## _to_cpup(y))
  41 #define uintBPL_t uint(BITS_PER_LONG)
  42 #define uint(x) xuint(x)
  43 #define xuint(x) __le ## x
  44
  45 static inline int find_next_one_bit(void *addr, int size, int offset)
  46 {
  47         uintBPL_t *p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG);
  48         int result = offset & ~(BITS_PER_LONG - 1);
  49         unsigned long tmp;
  50
  51         if (offset >= size)
  52                 return size;
  53         size -= result;
  54         offset &= (BITS_PER_LONG - 1);
  55         if (offset) {
  56                 tmp = leBPL_to_cpup(p++);
  57                 tmp &= ~0UL << offset;
  58                 if (size < BITS_PER_LONG)
  59                         goto found_first;
  60                 if (tmp)
  61                         goto found_middle;
  62                 size -= BITS_PER_LONG;
  63                 result += BITS_PER_LONG;
  64         }
  65         while (size & ~(BITS_PER_LONG - 1)) {
  66                 tmp = leBPL_to_cpup(p++);
  67                 if (tmp)
  68                         goto found_middle;
  69                 result += BITS_PER_LONG;
  70                 size -= BITS_PER_LONG;
  71         }
  72         if (!size)
  73                 return result;
  74         tmp = leBPL_to_cpup(p);
  75 found_first:
  76         tmp &= ~0UL >> (BITS_PER_LONG - size);
  77 found_middle:
  78         return result + ffz(~tmp);
  79 }
  80
  81 #define find_first_one_bit(addr, size)\
  82         find_next_one_bit((addr), (size), 0)
  83
  84 static int read_block_bitmap(struct super_block *sb,
  85                              struct udf_bitmap *bitmap, unsigned int block,
  86                              unsigned long bitmap_nr)
  87 {
  88         struct buffer_head *bh = NULL;
  89         int retval = 0;
  90         kernel_lb_addr loc;
  91
  92         loc.logicalBlockNum = bitmap->s_extPosition;
  93         loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
  94
  95         bh = udf_tread(sb, udf_get_lb_pblock(sb, loc, block));
  96         if (!bh)
  97                 retval = -EIO;
  98
  99         bitmap->s_block_bitmap[bitmap_nr] = bh;
 100         return retval;
 101 }
 102
 103 static int __load_block_bitmap(struct super_block *sb,
 104                                struct udf_bitmap *bitmap,
 105                                unsigned int block_group)
 106 {
 107         int retval = 0;
 108         int nr_groups = bitmap->s_nr_groups;
 109
 110         if (block_group >= nr_groups) {
 111                 udf_debug("block_group (%d) > nr_groups (%d)\n", block_group,
 112                           nr_groups);
 113         }
 114
 115         if (bitmap->s_block_bitmap[block_group]) {
 116                 return block_group;
 117         } else {
 118                 retval = read_block_bitmap(sb, bitmap, block_group,
 119                                            block_group);
 120                 if (retval < 0)
 121                         return retval;
 122                 return block_group;
 123         }
 124 }
 125
 126 static inline int load_block_bitmap(struct super_block *sb,
 127                                     struct udf_bitmap *bitmap,
 128                                     unsigned int block_group)
 129 {
 130         int slot;
 131
 132         slot = __load_block_bitmap(sb, bitmap, block_group);
 133
 134         if (slot < 0)
 135                 return slot;
 136
 137         if (!bitmap->s_block_bitmap[slot])
 138                 return -EIO;
 139
 140         return slot;
 141 }
 142
 143 static bool udf_add_free_space(struct udf_sb_info *sbi,
 144                                 u16 partition, u32 cnt)
 145 {
 146         struct logicalVolIntegrityDesc *lvid;
 147
 148         if (sbi->s_lvid_bh)
 149                 return false;
 150
 151         lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 152         lvid->freeSpaceTable[partition] = cpu_to_le32(le32_to_cpu(
 153                                         lvid->freeSpaceTable[partition]) + cnt);
 154         return true;
 155 }
 156
 157 static void udf_bitmap_free_blocks(struct super_block *sb,
 158                                    struct inode *inode,
 159                                    struct udf_bitmap *bitmap,
 160                                    kernel_lb_addr bloc, uint32_t offset,
 161                                    uint32_t count)
 162 {
 163         struct udf_sb_info *sbi = UDF_SB(sb);
 164         struct buffer_head *bh = NULL;
 165         unsigned long block;
 166         unsigned long block_group;
 167         unsigned long bit;
 168         unsigned long i;
 169         int bitmap_nr;
 170         unsigned long overflow;
 171
 172         mutex_lock(&sbi->s_alloc_mutex);
 173         if (bloc.logicalBlockNum < 0 ||
 174             (bloc.logicalBlockNum + count) >
 175                 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
 176                 udf_debug("%d < %d || %d + %d > %d\n",
 177                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 178                           sbi->s_partmaps[bloc.partitionReferenceNum].
 179                                                         s_partition_len);
 180                 goto error_return;
 181         }
 182
 183         block = bloc.logicalBlockNum + offset +
 184                 (sizeof(struct spaceBitmapDesc) << 3);
 185
 186         do {
 187                 overflow = 0;
 188                 block_group = block >> (sb->s_blocksize_bits + 3);
 189                 bit = block % (sb->s_blocksize << 3);
 190
 191                 /*
 192                 * Check to see if we are freeing blocks across a group boundary.
 193                 */
 194                 if (bit + count > (sb->s_blocksize << 3)) {
 195                         overflow = bit + count - (sb->s_blocksize << 3);
 196                         count -= overflow;
 197                 }
 198                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 199                 if (bitmap_nr < 0)
 200                         goto error_return;
 201
 202                 bh = bitmap->s_block_bitmap[bitmap_nr];
 203                 for (i = 0; i < count; i++) {
 204                         if (udf_set_bit(bit + i, bh->b_data)) {
 205                                 udf_debug("bit %ld already set\n", bit + i);
 206                                 udf_debug("byte=%2x\n",
 207                                         ((char *)bh->b_data)[(bit + i) >> 3]);
 208                         } else {
 209                                 if (inode)
 210                                         DQUOT_FREE_BLOCK(inode, 1);
 211                                 udf_add_free_space(sbi, sbi->s_partition, 1);
 212                         }
 213                 }
 214                 mark_buffer_dirty(bh);
 215                 if (overflow) {
 216                         block += count;
 217                         count = overflow;
 218                 }
 219         } while (overflow);
 220
 221 error_return:
 222         sb->s_dirt = 1;
 223         if (sbi->s_lvid_bh)
 224                 mark_buffer_dirty(sbi->s_lvid_bh);
 225         mutex_unlock(&sbi->s_alloc_mutex);
 226 }
 227
 228 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 229                                       struct inode *inode,
 230                                       struct udf_bitmap *bitmap,
 231                                       uint16_t partition, uint32_t first_block,
 232                                       uint32_t block_count)
 233 {
 234         struct udf_sb_info *sbi = UDF_SB(sb);
 235         int alloc_count = 0;
 236         int bit, block, block_group, group_start;
 237         int nr_groups, bitmap_nr;
 238         struct buffer_head *bh;
 239         __u32 part_len;
 240
 241         mutex_lock(&sbi->s_alloc_mutex);
 242         part_len = sbi->s_partmaps[partition].s_partition_len;
 243         if (first_block < 0 || first_block >= part_len)
 244                 goto out;
 245
 246         if (first_block + block_count > part_len)
 247                 block_count = part_len - first_block;
 248
 249         do {
 250                 nr_groups = udf_compute_nr_groups(sb, partition);
 251                 block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 252                 block_group = block >> (sb->s_blocksize_bits + 3);
 253                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 254
 255                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 256                 if (bitmap_nr < 0)
 257                         goto out;
 258                 bh = bitmap->s_block_bitmap[bitmap_nr];
 259
 260                 bit = block % (sb->s_blocksize << 3);
 261
 262                 while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 263                         if (!udf_test_bit(bit, bh->b_data))
 264                                 goto out;
 265                         else if (DQUOT_PREALLOC_BLOCK(inode, 1))
 266                                 goto out;
 267                         else if (!udf_clear_bit(bit, bh->b_data)) {
 268                                 udf_debug("bit already cleared for block %d\n", bit);
 269                                 DQUOT_FREE_BLOCK(inode, 1);
 270                                 goto out;
 271                         }
 272                         block_count--;
 273                         alloc_count++;
 274                         bit++;
 275                         block++;
 276                 }
 277                 mark_buffer_dirty(bh);
 278         } while (block_count > 0);
 279
 280 out:
 281         if (udf_add_free_space(sbi, partition, -alloc_count))
 282                 mark_buffer_dirty(sbi->s_lvid_bh);
 283         sb->s_dirt = 1;
 284         mutex_unlock(&sbi->s_alloc_mutex);
 285         return alloc_count;
 286 }
 287
 288 static int udf_bitmap_new_block(struct super_block *sb,
 289                                 struct inode *inode,
 290                                 struct udf_bitmap *bitmap, uint16_t partition,
 291                                 uint32_t goal, int *err)
 292 {
 293         struct udf_sb_info *sbi = UDF_SB(sb);
 294         int newbit, bit = 0, block, block_group, group_start;
 295         int end_goal, nr_groups, bitmap_nr, i;
 296         struct buffer_head *bh = NULL;
 297         char *ptr;
 298         int newblock = 0;
 299
 300         *err = -ENOSPC;
 301         mutex_lock(&sbi->s_alloc_mutex);
 302
 303 repeat:
 304         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 305                 goal = 0;
 306
 307         nr_groups = bitmap->s_nr_groups;
 308         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 309         block_group = block >> (sb->s_blocksize_bits + 3);
 310         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 311
 312         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 313         if (bitmap_nr < 0)
 314                 goto error_return;
 315         bh = bitmap->s_block_bitmap[bitmap_nr];
 316         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 317                       sb->s_blocksize - group_start);
 318
 319         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 320                 bit = block % (sb->s_blocksize << 3);
 321                 if (udf_test_bit(bit, bh->b_data))
 322                         goto got_block;
 323
 324                 end_goal = (bit + 63) & ~63;
 325                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 326                 if (bit < end_goal)
 327                         goto got_block;
 328
 329                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
 330                               sb->s_blocksize - ((bit + 7) >> 3));
 331                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 332                 if (newbit < sb->s_blocksize << 3) {
 333                         bit = newbit;
 334                         goto search_back;
 335                 }
 336
 337                 newbit = udf_find_next_one_bit(bh->b_data,
 338                                                sb->s_blocksize << 3, bit);
 339                 if (newbit < sb->s_blocksize << 3) {
 340                         bit = newbit;
 341                         goto got_block;
 342                 }
 343         }
 344
 345         for (i = 0; i < (nr_groups * 2); i++) {
 346                 block_group++;
 347                 if (block_group >= nr_groups)
 348                         block_group = 0;
 349                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 350
 351                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 352                 if (bitmap_nr < 0)
 353                         goto error_return;
 354                 bh = bitmap->s_block_bitmap[bitmap_nr];
 355                 if (i < nr_groups) {
 356                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 357                                       sb->s_blocksize - group_start);
 358                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 359                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 360                                 break;
 361                         }
 362                 } else {
 363                         bit = udf_find_next_one_bit((char *)bh->b_data,
 364                                                     sb->s_blocksize << 3,
 365                                                     group_start << 3);
 366                         if (bit < sb->s_blocksize << 3)
 367                                 break;
 368                 }
 369         }
 370         if (i >= (nr_groups * 2)) {
 371                 mutex_unlock(&sbi->s_alloc_mutex);
 372                 return newblock;
 373         }
 374         if (bit < sb->s_blocksize << 3)
 375                 goto search_back;
 376         else
 377                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
 378                                             group_start << 3);
 379         if (bit >= sb->s_blocksize << 3) {
 380                 mutex_unlock(&sbi->s_alloc_mutex);
 381                 return 0;
 382         }
 383
 384 search_back:
 385         i = 0;
 386         while (i < 7 && bit > (group_start << 3) &&
 387                udf_test_bit(bit - 1, bh->b_data)) {
 388                 ++i;
 389                 --bit;
 390         }
 391
 392 got_block:
 393
 394         /*
 395          * Check quota for allocation of this block.
 396          */
 397         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 398                 mutex_unlock(&sbi->s_alloc_mutex);
 399                 *err = -EDQUOT;
 400                 return 0;
 401         }
 402
 403         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 404                 (sizeof(struct spaceBitmapDesc) << 3);
 405
 406         if (!udf_clear_bit(bit, bh->b_data)) {
 407                 udf_debug("bit already cleared for block %d\n", bit);
 408                 goto repeat;
 409         }
 410
 411         mark_buffer_dirty(bh);
 412
 413         if (udf_add_free_space(sbi, partition, -1))
 414                 mark_buffer_dirty(sbi->s_lvid_bh);
 415         sb->s_dirt = 1;
 416         mutex_unlock(&sbi->s_alloc_mutex);
 417         *err = 0;
 418         return newblock;
 419
 420 error_return:
 421         *err = -EIO;
 422         mutex_unlock(&sbi->s_alloc_mutex);
 423         return 0;
 424 }
 425
 426 static void udf_table_free_blocks(struct super_block *sb,
 427                                   struct inode *inode,
 428                                   struct inode *table,
 429                                   kernel_lb_addr bloc, uint32_t offset,
 430                                   uint32_t count)
 431 {
 432         struct udf_sb_info *sbi = UDF_SB(sb);
 433         uint32_t start, end;
 434         uint32_t elen;
 435         kernel_lb_addr eloc;
 436         struct extent_position oepos, epos;
 437         int8_t etype;
 438         int i;
 439
 440         mutex_lock(&sbi->s_alloc_mutex);
 441         if (bloc.logicalBlockNum < 0 ||
 442             (bloc.logicalBlockNum + count) >
 443                 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
 444                 udf_debug("%d < %d || %d + %d > %d\n",
 445                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 446                           sbi->s_partmaps[bloc.partitionReferenceNum].
 447                                                         s_partition_len);
 448                 goto error_return;
 449         }
 450
 451         /* We do this up front - There are some error conditions that
 452            could occure, but.. oh well */
 453         if (inode)
 454                 DQUOT_FREE_BLOCK(inode, count);
 455         if (udf_add_free_space(sbi, sbi->s_partition, count))
 456                 mark_buffer_dirty(sbi->s_lvid_bh);
 457
 458         start = bloc.logicalBlockNum + offset;
 459         end = bloc.logicalBlockNum + offset + count - 1;
 460
 461         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 462         elen = 0;
 463         epos.block = oepos.block = UDF_I(table)->i_location;
 464         epos.bh = oepos.bh = NULL;
 465
 466         while (count &&
 467                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 468                 if (((eloc.logicalBlockNum +
 469                         (elen >> sb->s_blocksize_bits)) == start)) {
 470                         if ((0x3FFFFFFF - elen) <
 471                                         (count << sb->s_blocksize_bits)) {
 472                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 473                                                         sb->s_blocksize_bits);
 474                                 count -= tmp;
 475                                 start += tmp;
 476                                 elen = (etype << 30) |
 477                                         (0x40000000 - sb->s_blocksize);
 478                         } else {
 479                                 elen = (etype << 30) |
 480                                         (elen +
 481                                         (count << sb->s_blocksize_bits));
 482                                 start += count;
 483                                 count = 0;
 484                         }
 485                         udf_write_aext(table, &oepos, eloc, elen, 1);
 486                 } else if (eloc.logicalBlockNum == (end + 1)) {
 487                         if ((0x3FFFFFFF - elen) <
 488                                         (count << sb->s_blocksize_bits)) {
 489                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 490                                                 sb->s_blocksize_bits);
 491                                 count -= tmp;
 492                                 end -= tmp;
 493                                 eloc.logicalBlockNum -= tmp;
 494                                 elen = (etype << 30) |
 495                                         (0x40000000 - sb->s_blocksize);
 496                         } else {
 497                                 eloc.logicalBlockNum = start;
 498                                 elen = (etype << 30) |
 499                                         (elen +
 500                                         (count << sb->s_blocksize_bits));
 501                                 end -= count;
 502                                 count = 0;
 503                         }
 504                         udf_write_aext(table, &oepos, eloc, elen, 1);
 505                 }
 506
 507                 if (epos.bh != oepos.bh) {
 508                         i = -1;
 509                         oepos.block = epos.block;
 510                         brelse(oepos.bh);
 511                         get_bh(epos.bh);
 512                         oepos.bh = epos.bh;
 513                         oepos.offset = 0;
 514                 } else {
 515                         oepos.offset = epos.offset;
 516                 }
 517         }
 518
 519         if (count) {
 520                 /*
 521                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
 522                  * allocate a new block, and since we hold the super block
 523                  * lock already very bad things would happen :)
 524                  *
 525                  * We copy the behavior of udf_add_aext, but instead of
 526                  * trying to allocate a new block close to the existing one,
 527                  * we just steal a block from the extent we are trying to add.
 528                  *
 529                  * It would be nice if the blocks were close together, but it
 530                  * isn't required.
 531                  */
 532
 533                 int adsize;
 534                 short_ad *sad = NULL;
 535                 long_ad *lad = NULL;
 536                 struct allocExtDesc *aed;
 537
 538                 eloc.logicalBlockNum = start;
 539                 elen = EXT_RECORDED_ALLOCATED |
 540                         (count << sb->s_blocksize_bits);
 541
 542                 if (UDF_I(table)->i_alloc_type == ICBTAG_FLAG_AD_SHORT) {
 543                         adsize = sizeof(short_ad);
 544                 } else if (UDF_I(table)->i_alloc_type == ICBTAG_FLAG_AD_LONG) {
 545                         adsize = sizeof(long_ad);
 546                 } else {
 547                         brelse(oepos.bh);
 548                         brelse(epos.bh);
 549                         goto error_return;
 550                 }
 551
 552                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 553                         char *sptr, *dptr;
 554                         int loffset;
 555
 556                         brelse(oepos.bh);
 557                         oepos = epos;
 558
 559                         /* Steal a block from the extent being free'd */
 560                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 561                         eloc.logicalBlockNum++;
 562                         elen -= sb->s_blocksize;
 563
 564                         epos.bh = udf_tread(sb,
 565                                         udf_get_lb_pblock(sb, epos.block, 0));
 566                         if (!epos.bh) {
 567                                 brelse(oepos.bh);
 568                                 goto error_return;
 569                         }
 570                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 571                         aed->previousAllocExtLocation =
 572                                 cpu_to_le32(oepos.block.logicalBlockNum);
 573                         if (epos.offset + adsize > sb->s_blocksize) {
 574                                 loffset = epos.offset;
 575                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 576                                 sptr = UDF_I(table)->i_ext.i_data + epos.offset
 577                                                                 - adsize;
 578                                 dptr = epos.bh->b_data +
 579                                         sizeof(struct allocExtDesc);
 580                                 memcpy(dptr, sptr, adsize);
 581                                 epos.offset = sizeof(struct allocExtDesc) +
 582                                                 adsize;
 583                         } else {
 584                                 loffset = epos.offset + adsize;
 585                                 aed->lengthAllocDescs = cpu_to_le32(0);
 586                                 if (oepos.bh) {
 587                                         sptr = oepos.bh->b_data + epos.offset;
 588                                         aed = (struct allocExtDesc *)
 589                                                 oepos.bh->b_data;
 590                                         aed->lengthAllocDescs =
 591                                                 cpu_to_le32(le32_to_cpu(
 592                                                         aed->lengthAllocDescs) +
 593                                                                 adsize);
 594                                 } else {
 595                                         sptr = UDF_I(table)->i_ext.i_data +
 596                                                                 epos.offset;
 597                                         UDF_I(table)->i_lenAlloc += 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(table)->i_alloc_type) {
 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(table)->i_lenAlloc += 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(table)->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 681                 adsize = sizeof(short_ad);
 682         else if (UDF_I(table)->i_alloc_type == 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(table)->i_location;
 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 && udf_add_free_space(sbi, partition, -alloc_count)) {
 723                 mark_buffer_dirty(sbi->s_lvid_bh);
 724                 sb->s_dirt = 1;
 725         }
 726         mutex_unlock(&sbi->s_alloc_mutex);
 727         return alloc_count;
 728 }
 729
 730 static int udf_table_new_block(struct super_block *sb,
 731                                struct inode *inode,
 732                                struct inode *table, uint16_t partition,
 733                                uint32_t goal, int *err)
 734 {
 735         struct udf_sb_info *sbi = UDF_SB(sb);
 736         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 737         uint32_t newblock = 0, adsize;
 738         uint32_t elen, goal_elen = 0;
 739         kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 740         struct extent_position epos, goal_epos;
 741         int8_t etype;
 742
 743         *err = -ENOSPC;
 744
 745         if (UDF_I(table)->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 746                 adsize = sizeof(short_ad);
 747         else if (UDF_I(table)->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 748                 adsize = sizeof(long_ad);
 749         else
 750                 return newblock;
 751
 752         mutex_lock(&sbi->s_alloc_mutex);
 753         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 754                 goal = 0;
 755
 756         /* We search for the closest matching block to goal. If we find
 757            a exact hit, we stop. Otherwise we keep going till we run out
 758            of extents. We store the buffer_head, bloc, and extoffset
 759            of the current closest match and use that when we are done.
 760          */
 761         epos.offset = sizeof(struct unallocSpaceEntry);
 762         epos.block = UDF_I(table)->i_location;
 763         epos.bh = goal_epos.bh = NULL;
 764
 765         while (spread &&
 766                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 767                 if (goal >= eloc.logicalBlockNum) {
 768                         if (goal < eloc.logicalBlockNum +
 769                                         (elen >> sb->s_blocksize_bits))
 770                                 nspread = 0;
 771                         else
 772                                 nspread = goal - eloc.logicalBlockNum -
 773                                         (elen >> sb->s_blocksize_bits);
 774                 } else {
 775                         nspread = eloc.logicalBlockNum - goal;
 776                 }
 777
 778                 if (nspread < spread) {
 779                         spread = nspread;
 780                         if (goal_epos.bh != epos.bh) {
 781                                 brelse(goal_epos.bh);
 782                                 goal_epos.bh = epos.bh;
 783                                 get_bh(goal_epos.bh);
 784                         }
 785                         goal_epos.block = epos.block;
 786                         goal_epos.offset = epos.offset - adsize;
 787                         goal_eloc = eloc;
 788                         goal_elen = (etype << 30) | elen;
 789                 }
 790         }
 791
 792         brelse(epos.bh);
 793
 794         if (spread == 0xFFFFFFFF) {
 795                 brelse(goal_epos.bh);
 796                 mutex_unlock(&sbi->s_alloc_mutex);
 797                 return 0;
 798         }
 799
 800         /* Only allocate blocks from the beginning of the extent.
 801            That way, we only delete (empty) extents, never have to insert an
 802            extent because of splitting */
 803         /* This works, but very poorly.... */
 804
 805         newblock = goal_eloc.logicalBlockNum;
 806         goal_eloc.logicalBlockNum++;
 807         goal_elen -= sb->s_blocksize;
 808
 809         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 810                 brelse(goal_epos.bh);
 811                 mutex_unlock(&sbi->s_alloc_mutex);
 812                 *err = -EDQUOT;
 813                 return 0;
 814         }
 815
 816         if (goal_elen)
 817                 udf_write_aext(table, &goal_epos, goal_eloc, goal_elen, 1);
 818         else
 819                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 820         brelse(goal_epos.bh);
 821
 822         if (udf_add_free_space(sbi, partition, -1))
 823                 mark_buffer_dirty(sbi->s_lvid_bh);
 824
 825         sb->s_dirt = 1;
 826         mutex_unlock(&sbi->s_alloc_mutex);
 827         *err = 0;
 828         return newblock;
 829 }
 830
 831 inline void udf_free_blocks(struct super_block *sb,
 832                             struct inode *inode,
 833                             kernel_lb_addr bloc, uint32_t offset,
 834                             uint32_t count)
 835 {
 836         uint16_t partition = bloc.partitionReferenceNum;
 837         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 838
 839         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 840                 return udf_bitmap_free_blocks(sb, inode,
 841                                               map->s_uspace.s_bitmap,
 842                                               bloc, offset, count);
 843         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 844                 return udf_table_free_blocks(sb, inode,
 845                                              map->s_uspace.s_table,
 846                                              bloc, offset, count);
 847         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 848                 return udf_bitmap_free_blocks(sb, inode,
 849                                               map->s_fspace.s_bitmap,
 850                                               bloc, offset, count);
 851         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 852                 return udf_table_free_blocks(sb, inode,
 853                                              map->s_fspace.s_table,
 854                                              bloc, offset, count);
 855         } else {
 856                 return;
 857         }
 858 }
 859
 860 inline int udf_prealloc_blocks(struct super_block *sb,
 861                                struct inode *inode,
 862                                uint16_t partition, uint32_t first_block,
 863                                uint32_t block_count)
 864 {
 865         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 866
 867         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 868                 return udf_bitmap_prealloc_blocks(sb, inode,
 869                                                   map->s_uspace.s_bitmap,
 870                                                   partition, first_block,
 871                                                   block_count);
 872         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 873                 return udf_table_prealloc_blocks(sb, inode,
 874                                                  map->s_uspace.s_table,
 875                                                  partition, first_block,
 876                                                  block_count);
 877         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 878                 return udf_bitmap_prealloc_blocks(sb, inode,
 879                                                   map->s_fspace.s_bitmap,
 880                                                   partition, first_block,
 881                                                   block_count);
 882         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 883                 return udf_table_prealloc_blocks(sb, inode,
 884                                                  map->s_fspace.s_table,
 885                                                  partition, first_block,
 886                                                  block_count);
 887         else
 888                 return 0;
 889 }
 890
 891 inline int udf_new_block(struct super_block *sb,
 892                          struct inode *inode,
 893                          uint16_t partition, uint32_t goal, int *err)
 894 {
 895         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 896
 897         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 898                 return udf_bitmap_new_block(sb, inode,
 899                                            map->s_uspace.s_bitmap,
 900                                            partition, goal, err);
 901         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 902                 return udf_table_new_block(sb, inode,
 903                                            map->s_uspace.s_table,
 904                                            partition, goal, err);
 905         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 906                 return udf_bitmap_new_block(sb, inode,
 907                                             map->s_fspace.s_bitmap,
 908                                             partition, goal, err);
 909         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 910                 return udf_table_new_block(sb, inode,
 911                                            map->s_fspace.s_table,
 912                                            partition, goal, err);
 913         else {
 914                 *err = -EIO;
 915                 return 0;
 916         }
 917 }