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_PARTITION(sb);
  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) > UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum)) {
 159                 udf_debug("%d < %d || %d + %d > %d\n",
 160                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 161                           UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum));
 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 (UDF_SB_LVIDBH(sb)) {
 192                                 UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)] =
 193                                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)]) + 1);
 194                         }
 195                 }
 196         }
 197         mark_buffer_dirty(bh);
 198         if (overflow) {
 199                 block += count;
 200                 count = overflow;
 201                 goto do_more;
 202         }
 203 error_return:
 204         sb->s_dirt = 1;
 205         if (UDF_SB_LVIDBH(sb))
 206                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 207         mutex_unlock(&sbi->s_alloc_mutex);
 208         return;
 209 }
 210
 211 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 212                                       struct inode *inode,
 213                                       struct udf_bitmap *bitmap,
 214                                       uint16_t partition, uint32_t first_block,
 215                                       uint32_t block_count)
 216 {
 217         struct udf_sb_info *sbi = UDF_SB(sb);
 218         int alloc_count = 0;
 219         int bit, block, block_group, group_start;
 220         int nr_groups, bitmap_nr;
 221         struct buffer_head *bh;
 222
 223         mutex_lock(&sbi->s_alloc_mutex);
 224         if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
 225                 goto out;
 226
 227         if (first_block + block_count > UDF_SB_PARTLEN(sb, partition))
 228                 block_count = UDF_SB_PARTLEN(sb, partition) - first_block;
 229
 230 repeat:
 231         nr_groups = (UDF_SB_PARTLEN(sb, partition) +
 232                      (sizeof(struct spaceBitmapDesc) << 3) +
 233                      (sb->s_blocksize * 8) - 1) / (sb->s_blocksize * 8);
 234         block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 235         block_group = block >> (sb->s_blocksize_bits + 3);
 236         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 237
 238         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 239         if (bitmap_nr < 0)
 240                 goto out;
 241         bh = bitmap->s_block_bitmap[bitmap_nr];
 242
 243         bit = block % (sb->s_blocksize << 3);
 244
 245         while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 246                 if (!udf_test_bit(bit, bh->b_data)) {
 247                         goto out;
 248                 } else if (DQUOT_PREALLOC_BLOCK(inode, 1)) {
 249                         goto out;
 250                 } else if (!udf_clear_bit(bit, bh->b_data)) {
 251                         udf_debug("bit already cleared for block %d\n", bit);
 252                         DQUOT_FREE_BLOCK(inode, 1);
 253                         goto out;
 254                 }
 255                 block_count--;
 256                 alloc_count++;
 257                 bit++;
 258                 block++;
 259         }
 260         mark_buffer_dirty(bh);
 261         if (block_count > 0)
 262                 goto repeat;
 263 out:
 264         if (UDF_SB_LVIDBH(sb)) {
 265                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 266                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition]) - alloc_count);
 267                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 268         }
 269         sb->s_dirt = 1;
 270         mutex_unlock(&sbi->s_alloc_mutex);
 271         return alloc_count;
 272 }
 273
 274 static int udf_bitmap_new_block(struct super_block *sb,
 275                                 struct inode *inode,
 276                                 struct udf_bitmap *bitmap, uint16_t partition,
 277                                 uint32_t goal, int *err)
 278 {
 279         struct udf_sb_info *sbi = UDF_SB(sb);
 280         int newbit, bit = 0, block, block_group, group_start;
 281         int end_goal, nr_groups, bitmap_nr, i;
 282         struct buffer_head *bh = NULL;
 283         char *ptr;
 284         int newblock = 0;
 285
 286         *err = -ENOSPC;
 287         mutex_lock(&sbi->s_alloc_mutex);
 288
 289 repeat:
 290         if (goal < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
 291                 goal = 0;
 292
 293         nr_groups = bitmap->s_nr_groups;
 294         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 295         block_group = block >> (sb->s_blocksize_bits + 3);
 296         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 297
 298         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 299         if (bitmap_nr < 0)
 300                 goto error_return;
 301         bh = bitmap->s_block_bitmap[bitmap_nr];
 302         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 303                       sb->s_blocksize - group_start);
 304
 305         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 306                 bit = block % (sb->s_blocksize << 3);
 307                 if (udf_test_bit(bit, bh->b_data))
 308                         goto got_block;
 309
 310                 end_goal = (bit + 63) & ~63;
 311                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 312                 if (bit < end_goal)
 313                         goto got_block;
 314
 315                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF, sb->s_blocksize - ((bit + 7) >> 3));
 316                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 317                 if (newbit < sb->s_blocksize << 3) {
 318                         bit = newbit;
 319                         goto search_back;
 320                 }
 321
 322                 newbit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, bit);
 323                 if (newbit < sb->s_blocksize << 3) {
 324                         bit = newbit;
 325                         goto got_block;
 326                 }
 327         }
 328
 329         for (i = 0; i < (nr_groups * 2); i++) {
 330                 block_group++;
 331                 if (block_group >= nr_groups)
 332                         block_group = 0;
 333                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 334
 335                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 336                 if (bitmap_nr < 0)
 337                         goto error_return;
 338                 bh = bitmap->s_block_bitmap[bitmap_nr];
 339                 if (i < nr_groups) {
 340                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 341                                       sb->s_blocksize - group_start);
 342                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 343                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 344                                 break;
 345                         }
 346                 } else {
 347                         bit = udf_find_next_one_bit((char *)bh->b_data,
 348                                                     sb->s_blocksize << 3,
 349                                                     group_start << 3);
 350                         if (bit < sb->s_blocksize << 3)
 351                                 break;
 352                 }
 353         }
 354         if (i >= (nr_groups * 2)) {
 355                 mutex_unlock(&sbi->s_alloc_mutex);
 356                 return newblock;
 357         }
 358         if (bit < sb->s_blocksize << 3)
 359                 goto search_back;
 360         else
 361                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, group_start << 3);
 362         if (bit >= sb->s_blocksize << 3) {
 363                 mutex_unlock(&sbi->s_alloc_mutex);
 364                 return 0;
 365         }
 366
 367 search_back:
 368         for (i = 0; i < 7 && bit > (group_start << 3) && udf_test_bit(bit - 1, bh->b_data); i++, bit--)
 369                 ; /* empty loop */
 370
 371 got_block:
 372
 373         /*
 374          * Check quota for allocation of this block.
 375          */
 376         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 377                 mutex_unlock(&sbi->s_alloc_mutex);
 378                 *err = -EDQUOT;
 379                 return 0;
 380         }
 381
 382         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 383                 (sizeof(struct spaceBitmapDesc) << 3);
 384
 385         if (!udf_clear_bit(bit, bh->b_data)) {
 386                 udf_debug("bit already cleared for block %d\n", bit);
 387                 goto repeat;
 388         }
 389
 390         mark_buffer_dirty(bh);
 391
 392         if (UDF_SB_LVIDBH(sb)) {
 393                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 394                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition]) - 1);
 395                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 396         }
 397         sb->s_dirt = 1;
 398         mutex_unlock(&sbi->s_alloc_mutex);
 399         *err = 0;
 400         return newblock;
 401
 402 error_return:
 403         *err = -EIO;
 404         mutex_unlock(&sbi->s_alloc_mutex);
 405         return 0;
 406 }
 407
 408 static void udf_table_free_blocks(struct super_block *sb,
 409                                   struct inode *inode,
 410                                   struct inode *table,
 411                                   kernel_lb_addr bloc, uint32_t offset,
 412                                   uint32_t count)
 413 {
 414         struct udf_sb_info *sbi = UDF_SB(sb);
 415         uint32_t start, end;
 416         uint32_t elen;
 417         kernel_lb_addr eloc;
 418         struct extent_position oepos, epos;
 419         int8_t etype;
 420         int i;
 421
 422         mutex_lock(&sbi->s_alloc_mutex);
 423         if (bloc.logicalBlockNum < 0 ||
 424             (bloc.logicalBlockNum + count) > UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum)) {
 425                 udf_debug("%d < %d || %d + %d > %d\n",
 426                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 427                           UDF_SB_PARTLEN(sb, bloc.partitionReferenceNum));
 428                 goto error_return;
 429         }
 430
 431         /* We do this up front - There are some error conditions that could occure,
 432            but.. oh well */
 433         if (inode)
 434                 DQUOT_FREE_BLOCK(inode, count);
 435         if (UDF_SB_LVIDBH(sb)) {
 436                 UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)] =
 437                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)]) + count);
 438                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 439         }
 440
 441         start = bloc.logicalBlockNum + offset;
 442         end = bloc.logicalBlockNum + offset + count - 1;
 443
 444         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 445         elen = 0;
 446         epos.block = oepos.block = UDF_I_LOCATION(table);
 447         epos.bh = oepos.bh = NULL;
 448
 449         while (count &&
 450                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 451                 if (((eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits)) == start)) {
 452                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits)) {
 453                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 454                                 start += ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 455                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 456                         } else {
 457                                 elen = (etype << 30) | (elen + (count << sb->s_blocksize_bits));
 458                                 start += count;
 459                                 count = 0;
 460                         }
 461                         udf_write_aext(table, &oepos, eloc, elen, 1);
 462                 } else if (eloc.logicalBlockNum == (end + 1)) {
 463                         if ((0x3FFFFFFF - elen) < (count << sb->s_blocksize_bits)) {
 464                                 count -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 465                                 end -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 466                                 eloc.logicalBlockNum -= ((0x3FFFFFFF - elen) >> sb->s_blocksize_bits);
 467                                 elen = (etype << 30) | (0x40000000 - sb->s_blocksize);
 468                         } else {
 469                                 eloc.logicalBlockNum = start;
 470                                 elen = (etype << 30) | (elen + (count << sb->s_blocksize_bits));
 471                                 end -= count;
 472                                 count = 0;
 473                         }
 474                         udf_write_aext(table, &oepos, eloc, elen, 1);
 475                 }
 476
 477                 if (epos.bh != oepos.bh) {
 478                         i = -1;
 479                         oepos.block = epos.block;
 480                         brelse(oepos.bh);
 481                         get_bh(epos.bh);
 482                         oepos.bh = epos.bh;
 483                         oepos.offset = 0;
 484                 } else {
 485                         oepos.offset = epos.offset;
 486                 }
 487         }
 488
 489         if (count) {
 490                 /*
 491                  * NOTE: we CANNOT use udf_add_aext here, as it can try to allocate
 492                  * a new block, and since we hold the super block lock already
 493                  * very bad things would happen :)
 494                  *
 495                  * We copy the behavior of udf_add_aext, but instead of
 496                  * trying to allocate a new block close to the existing one,
 497                  * we just steal a block from the extent we are trying to add.
 498                  *
 499                  * It would be nice if the blocks were close together, but it
 500                  * isn't required.
 501                  */
 502
 503                 int adsize;
 504                 short_ad *sad = NULL;
 505                 long_ad *lad = NULL;
 506                 struct allocExtDesc *aed;
 507
 508                 eloc.logicalBlockNum = start;
 509                 elen = EXT_RECORDED_ALLOCATED |
 510                         (count << sb->s_blocksize_bits);
 511
 512                 if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT) {
 513                         adsize = sizeof(short_ad);
 514                 } else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG) {
 515                         adsize = sizeof(long_ad);
 516                 } else {
 517                         brelse(oepos.bh);
 518                         brelse(epos.bh);
 519                         goto error_return;
 520                 }
 521
 522                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 523                         char *sptr, *dptr;
 524                         int loffset;
 525
 526                         brelse(oepos.bh);
 527                         oepos = epos;
 528
 529                         /* Steal a block from the extent being free'd */
 530                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 531                         eloc.logicalBlockNum++;
 532                         elen -= sb->s_blocksize;
 533
 534                         if (!(epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, epos.block, 0)))) {
 535                                 brelse(oepos.bh);
 536                                 goto error_return;
 537                         }
 538                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 539                         aed->previousAllocExtLocation = cpu_to_le32(oepos.block.logicalBlockNum);
 540                         if (epos.offset + adsize > sb->s_blocksize) {
 541                                 loffset = epos.offset;
 542                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 543                                 sptr = UDF_I_DATA(table) + epos.offset - adsize;
 544                                 dptr = epos.bh->b_data + sizeof(struct allocExtDesc);
 545                                 memcpy(dptr, sptr, adsize);
 546                                 epos.offset = sizeof(struct allocExtDesc) + adsize;
 547                         } else {
 548                                 loffset = epos.offset + adsize;
 549                                 aed->lengthAllocDescs = cpu_to_le32(0);
 550                                 if (oepos.bh) {
 551                                         sptr = oepos.bh->b_data + epos.offset;
 552                                         aed = (struct allocExtDesc *)oepos.bh->b_data;
 553                                         aed->lengthAllocDescs =
 554                                                 cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 555                                 } else {
 556                                         sptr = UDF_I_DATA(table) + epos.offset;
 557                                         UDF_I_LENALLOC(table) += adsize;
 558                                         mark_inode_dirty(table);
 559                                 }
 560                                 epos.offset = sizeof(struct allocExtDesc);
 561                         }
 562                         if (UDF_SB_UDFREV(sb) >= 0x0200)
 563                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 3, 1,
 564                                             epos.block.logicalBlockNum, sizeof(tag));
 565                         else
 566                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 2, 1,
 567                                             epos.block.logicalBlockNum, sizeof(tag));
 568
 569                         switch (UDF_I_ALLOCTYPE(table)) {
 570                                 case ICBTAG_FLAG_AD_SHORT:
 571                                         sad = (short_ad *)sptr;
 572                                         sad->extLength = cpu_to_le32(
 573                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 574                                                 sb->s_blocksize);
 575                                         sad->extPosition = cpu_to_le32(epos.block.logicalBlockNum);
 576                                         break;
 577                                 case ICBTAG_FLAG_AD_LONG:
 578                                         lad = (long_ad *)sptr;
 579                                         lad->extLength = cpu_to_le32(
 580                                                 EXT_NEXT_EXTENT_ALLOCDECS |
 581                                                 sb->s_blocksize);
 582                                         lad->extLocation = cpu_to_lelb(epos.block);
 583                                         break;
 584                         }
 585                         if (oepos.bh) {
 586                                 udf_update_tag(oepos.bh->b_data, loffset);
 587                                 mark_buffer_dirty(oepos.bh);
 588                         } else {
 589                                 mark_inode_dirty(table);
 590                         }
 591                 }
 592
 593                 if (elen) { /* It's possible that stealing the block emptied the extent */
 594                         udf_write_aext(table, &epos, eloc, elen, 1);
 595
 596                         if (!epos.bh) {
 597                                 UDF_I_LENALLOC(table) += adsize;
 598                                 mark_inode_dirty(table);
 599                         } else {
 600                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 601                                 aed->lengthAllocDescs =
 602                                         cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
 603                                 udf_update_tag(epos.bh->b_data, epos.offset);
 604                                 mark_buffer_dirty(epos.bh);
 605                         }
 606                 }
 607         }
 608
 609         brelse(epos.bh);
 610         brelse(oepos.bh);
 611
 612 error_return:
 613         sb->s_dirt = 1;
 614         mutex_unlock(&sbi->s_alloc_mutex);
 615         return;
 616 }
 617
 618 static int udf_table_prealloc_blocks(struct super_block *sb,
 619                                      struct inode *inode,
 620                                      struct inode *table, uint16_t partition,
 621                                      uint32_t first_block, uint32_t block_count)
 622 {
 623         struct udf_sb_info *sbi = UDF_SB(sb);
 624         int alloc_count = 0;
 625         uint32_t elen, adsize;
 626         kernel_lb_addr eloc;
 627         struct extent_position epos;
 628         int8_t etype = -1;
 629
 630         if (first_block < 0 || first_block >= UDF_SB_PARTLEN(sb, partition))
 631                 return 0;
 632
 633         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 634                 adsize = sizeof(short_ad);
 635         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 636                 adsize = sizeof(long_ad);
 637         else
 638                 return 0;
 639
 640         mutex_lock(&sbi->s_alloc_mutex);
 641         epos.offset = sizeof(struct unallocSpaceEntry);
 642         epos.block = UDF_I_LOCATION(table);
 643         epos.bh = NULL;
 644         eloc.logicalBlockNum = 0xFFFFFFFF;
 645
 646         while (first_block != eloc.logicalBlockNum &&
 647                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 648                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 649                           eloc.logicalBlockNum, elen, first_block);
 650                 ; /* empty loop body */
 651         }
 652
 653         if (first_block == eloc.logicalBlockNum) {
 654                 epos.offset -= adsize;
 655
 656                 alloc_count = (elen >> sb->s_blocksize_bits);
 657                 if (inode && DQUOT_PREALLOC_BLOCK(inode, alloc_count > block_count ? block_count : alloc_count)) {
 658                         alloc_count = 0;
 659                 } else if (alloc_count > block_count) {
 660                         alloc_count = block_count;
 661                         eloc.logicalBlockNum += alloc_count;
 662                         elen -= (alloc_count << sb->s_blocksize_bits);
 663                         udf_write_aext(table, &epos, eloc, (etype << 30) | elen, 1);
 664                 } else {
 665                         udf_delete_aext(table, epos, eloc, (etype << 30) | elen);
 666                 }
 667         } else {
 668                 alloc_count = 0;
 669         }
 670
 671         brelse(epos.bh);
 672
 673         if (alloc_count && UDF_SB_LVIDBH(sb)) {
 674                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 675                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition]) - alloc_count);
 676                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 677                 sb->s_dirt = 1;
 678         }
 679         mutex_unlock(&sbi->s_alloc_mutex);
 680         return alloc_count;
 681 }
 682
 683 static int udf_table_new_block(struct super_block *sb,
 684                                struct inode *inode,
 685                                struct inode *table, uint16_t partition,
 686                                uint32_t goal, int *err)
 687 {
 688         struct udf_sb_info *sbi = UDF_SB(sb);
 689         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 690         uint32_t newblock = 0, adsize;
 691         uint32_t elen, goal_elen = 0;
 692         kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 693         struct extent_position epos, goal_epos;
 694         int8_t etype;
 695
 696         *err = -ENOSPC;
 697
 698         if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_SHORT)
 699                 adsize = sizeof(short_ad);
 700         else if (UDF_I_ALLOCTYPE(table) == ICBTAG_FLAG_AD_LONG)
 701                 adsize = sizeof(long_ad);
 702         else
 703                 return newblock;
 704
 705         mutex_lock(&sbi->s_alloc_mutex);
 706         if (goal < 0 || goal >= UDF_SB_PARTLEN(sb, partition))
 707                 goal = 0;
 708
 709         /* We search for the closest matching block to goal. If we find a exact hit,
 710            we stop. Otherwise we keep going till we run out of extents.
 711            We store the buffer_head, bloc, and extoffset of the current closest
 712            match and use that when we are done.
 713          */
 714         epos.offset = sizeof(struct unallocSpaceEntry);
 715         epos.block = UDF_I_LOCATION(table);
 716         epos.bh = goal_epos.bh = NULL;
 717
 718         while (spread &&
 719                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 720                 if (goal >= eloc.logicalBlockNum) {
 721                         if (goal < eloc.logicalBlockNum + (elen >> sb->s_blocksize_bits))
 722                                 nspread = 0;
 723                         else
 724                                 nspread = goal - eloc.logicalBlockNum -
 725                                         (elen >> sb->s_blocksize_bits);
 726                 } else {
 727                         nspread = eloc.logicalBlockNum - goal;
 728                 }
 729
 730                 if (nspread < spread) {
 731                         spread = nspread;
 732                         if (goal_epos.bh != epos.bh) {
 733                                 brelse(goal_epos.bh);
 734                                 goal_epos.bh = epos.bh;
 735                                 get_bh(goal_epos.bh);
 736                         }
 737                         goal_epos.block = epos.block;
 738                         goal_epos.offset = epos.offset - adsize;
 739                         goal_eloc = eloc;
 740                         goal_elen = (etype << 30) | elen;
 741                 }
 742         }
 743
 744         brelse(epos.bh);
 745
 746         if (spread == 0xFFFFFFFF) {
 747                 brelse(goal_epos.bh);
 748                 mutex_unlock(&sbi->s_alloc_mutex);
 749                 return 0;
 750         }
 751
 752         /* Only allocate blocks from the beginning of the extent.
 753            That way, we only delete (empty) extents, never have to insert an
 754            extent because of splitting */
 755         /* This works, but very poorly.... */
 756
 757         newblock = goal_eloc.logicalBlockNum;
 758         goal_eloc.logicalBlockNum++;
 759         goal_elen -= sb->s_blocksize;
 760
 761         if (inode && DQUOT_ALLOC_BLOCK(inode, 1)) {
 762                 brelse(goal_epos.bh);
 763                 mutex_unlock(&sbi->s_alloc_mutex);
 764                 *err = -EDQUOT;
 765                 return 0;
 766         }
 767
 768         if (goal_elen)
 769                 udf_write_aext(table, &goal_epos, goal_eloc, goal_elen, 1);
 770         else
 771                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 772         brelse(goal_epos.bh);
 773
 774         if (UDF_SB_LVIDBH(sb)) {
 775                 UDF_SB_LVID(sb)->freeSpaceTable[partition] =
 776                         cpu_to_le32(le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[partition]) - 1);
 777                 mark_buffer_dirty(UDF_SB_LVIDBH(sb));
 778         }
 779
 780         sb->s_dirt = 1;
 781         mutex_unlock(&sbi->s_alloc_mutex);
 782         *err = 0;
 783         return newblock;
 784 }
 785
 786 inline void udf_free_blocks(struct super_block *sb,
 787                             struct inode *inode,
 788                             kernel_lb_addr bloc, uint32_t offset,
 789                             uint32_t count)
 790 {
 791         uint16_t partition = bloc.partitionReferenceNum;
 792
 793         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP) {
 794                 return udf_bitmap_free_blocks(sb, inode,
 795                                               UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 796                                               bloc, offset, count);
 797         } else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE) {
 798                 return udf_table_free_blocks(sb, inode,
 799                                              UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 800                                              bloc, offset, count);
 801         } else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP) {
 802                 return udf_bitmap_free_blocks(sb, inode,
 803                                               UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 804                                               bloc, offset, count);
 805         } else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE) {
 806                 return udf_table_free_blocks(sb, inode,
 807                                              UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 808                                              bloc, offset, count);
 809         } else {
 810                 return;
 811         }
 812 }
 813
 814 inline int udf_prealloc_blocks(struct super_block *sb,
 815                                struct inode *inode,
 816                                uint16_t partition, uint32_t first_block,
 817                                uint32_t block_count)
 818 {
 819         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP) {
 820                 return udf_bitmap_prealloc_blocks(sb, inode,
 821                                                   UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 822                                                   partition, first_block, block_count);
 823         } else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE) {
 824                 return udf_table_prealloc_blocks(sb, inode,
 825                                                  UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 826                                                  partition, first_block, block_count);
 827         } else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP) {
 828                 return udf_bitmap_prealloc_blocks(sb, inode,
 829                                                   UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 830                                                   partition, first_block, block_count);
 831         } else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE) {
 832                 return udf_table_prealloc_blocks(sb, inode,
 833                                                  UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 834                                                  partition, first_block, block_count);
 835         } else {
 836                 return 0;
 837         }
 838 }
 839
 840 inline int udf_new_block(struct super_block *sb,
 841                          struct inode *inode,
 842                          uint16_t partition, uint32_t goal, int *err)
 843 {
 844         int ret;
 845
 846         if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_BITMAP) {
 847                 ret = udf_bitmap_new_block(sb, inode,
 848                                            UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_bitmap,
 849                                            partition, goal, err);
 850                 return ret;
 851         } else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_UNALLOC_TABLE) {
 852                 return udf_table_new_block(sb, inode,
 853                                            UDF_SB_PARTMAPS(sb)[partition].s_uspace.s_table,
 854                                            partition, goal, err);
 855         } else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_BITMAP) {
 856                 return udf_bitmap_new_block(sb, inode,
 857                                             UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_bitmap,
 858                                             partition, goal, err);
 859         } else if (UDF_SB_PARTFLAGS(sb, partition) & UDF_PART_FLAG_FREED_TABLE) {
 860                 return udf_table_new_block(sb, inode,
 861                                            UDF_SB_PARTMAPS(sb)[partition].s_fspace.s_table,
 862                                            partition, goal, err);
 863         } else {
 864                 *err = -EIO;
 865                 return 0;
 866         }
 867 }