git.oblomov.eu Git - linux-2.6/blob - fs/udf/balloc.c

   1 /*
   2  * balloc.c
   3  *
   4  * PURPOSE
   5  *      Block allocation handling routines for the OSTA-UDF(tm) filesystem.
   6  *
   7  * COPYRIGHT
   8  *      This file is distributed under the terms of the GNU General Public
   9  *      License (GPL). Copies of the GPL can be obtained from:
  10  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
  11  *      Each contributing author retains all rights to their own work.
  12  *
  13  *  (C) 1999-2001 Ben Fennema
  14  *  (C) 1999 Stelias Computing Inc
  15  *
  16  * HISTORY
  17  *
  18  *  02/24/99 blf  Created.
  19  *
  20  */
  21
  22 #include "udfdecl.h"
  23
  24 #include <linux/quotaops.h>
  25 #include <linux/buffer_head.h>
  26 #include <linux/bitops.h>
  27
  28 #include "udf_i.h"
  29 #include "udf_sb.h"
  30
  31 #define udf_clear_bit(nr, addr) ext2_clear_bit(nr, addr)
  32 #define udf_set_bit(nr, addr) ext2_set_bit(nr, addr)
  33 #define udf_test_bit(nr, addr) ext2_test_bit(nr, addr)
  34 #define udf_find_first_one_bit(addr, size) find_first_one_bit(addr, size)
  35 #define udf_find_next_one_bit(addr, size, offset) \
  36                 find_next_one_bit(addr, size, offset)
  37
  38 #define leBPL_to_cpup(x) leNUM_to_cpup(BITS_PER_LONG, x)
  39 #define leNUM_to_cpup(x, y) xleNUM_to_cpup(x, y)
  40 #define xleNUM_to_cpup(x, y) (le ## x ## _to_cpup(y))
  41 #define uintBPL_t uint(BITS_PER_LONG)
  42 #define uint(x) xuint(x)
  43 #define xuint(x) __le ## x
  44
  45 static inline int find_next_one_bit(void *addr, int size, int offset)
  46 {
  47         uintBPL_t *p = ((uintBPL_t *) addr) + (offset / BITS_PER_LONG);
  48         int result = offset & ~(BITS_PER_LONG - 1);
  49         unsigned long tmp;
  50
  51         if (offset >= size)
  52                 return size;
  53         size -= result;
  54         offset &= (BITS_PER_LONG - 1);
  55         if (offset) {
  56                 tmp = leBPL_to_cpup(p++);
  57                 tmp &= ~0UL << offset;
  58                 if (size < BITS_PER_LONG)
  59                         goto found_first;
  60                 if (tmp)
  61                         goto found_middle;
  62                 size -= BITS_PER_LONG;
  63                 result += BITS_PER_LONG;
  64         }
  65         while (size & ~(BITS_PER_LONG - 1)) {
  66                 tmp = leBPL_to_cpup(p++);
  67                 if (tmp)
  68                         goto found_middle;
  69                 result += BITS_PER_LONG;
  70                 size -= BITS_PER_LONG;
  71         }
  72         if (!size)
  73                 return result;
  74         tmp = leBPL_to_cpup(p);
  75 found_first:
  76         tmp &= ~0UL >> (BITS_PER_LONG - size);
  77 found_middle:
  78         return result + ffz(~tmp);
  79 }
  80
  81 #define find_first_one_bit(addr, size)\
  82         find_next_one_bit((addr), (size), 0)
  83
  84 static int read_block_bitmap(struct super_block *sb,
  85                              struct udf_bitmap *bitmap, unsigned int block,
  86                              unsigned long bitmap_nr)
  87 {
  88         struct buffer_head *bh = NULL;
  89         int retval = 0;
  90         struct 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 == NULL)
 149                 return false;
 150
 151         lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 152         le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
 153         return true;
 154 }
 155
 156 static void udf_bitmap_free_blocks(struct super_block *sb,
 157                                    struct inode *inode,
 158                                    struct udf_bitmap *bitmap,
 159                                    struct kernel_lb_addr bloc, uint32_t offset,
 160                                    uint32_t count)
 161 {
 162         struct udf_sb_info *sbi = UDF_SB(sb);
 163         struct buffer_head *bh = NULL;
 164         unsigned long block;
 165         unsigned long block_group;
 166         unsigned long bit;
 167         unsigned long i;
 168         int bitmap_nr;
 169         unsigned long overflow;
 170
 171         mutex_lock(&sbi->s_alloc_mutex);
 172         if (bloc.logicalBlockNum < 0 ||
 173             (bloc.logicalBlockNum + count) >
 174                 sbi->s_partmaps[bloc.partitionReferenceNum].s_partition_len) {
 175                 udf_debug("%d < %d || %d + %d > %d\n",
 176                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 177                           sbi->s_partmaps[bloc.partitionReferenceNum].
 178                                                         s_partition_len);
 179                 goto error_return;
 180         }
 181
 182         block = bloc.logicalBlockNum + offset +
 183                 (sizeof(struct spaceBitmapDesc) << 3);
 184
 185         do {
 186                 overflow = 0;
 187                 block_group = block >> (sb->s_blocksize_bits + 3);
 188                 bit = block % (sb->s_blocksize << 3);
 189
 190                 /*
 191                 * Check to see if we are freeing blocks across a group boundary.
 192                 */
 193                 if (bit + count > (sb->s_blocksize << 3)) {
 194                         overflow = bit + count - (sb->s_blocksize << 3);
 195                         count -= overflow;
 196                 }
 197                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 198                 if (bitmap_nr < 0)
 199                         goto error_return;
 200
 201                 bh = bitmap->s_block_bitmap[bitmap_nr];
 202                 for (i = 0; i < count; i++) {
 203                         if (udf_set_bit(bit + i, bh->b_data)) {
 204                                 udf_debug("bit %ld already set\n", bit + i);
 205                                 udf_debug("byte=%2x\n",
 206                                         ((char *)bh->b_data)[(bit + i) >> 3]);
 207                         } else {
 208                                 if (inode)
 209                                         vfs_dq_free_block(inode, 1);
 210                                 udf_add_free_space(sbi, sbi->s_partition, 1);
 211                         }
 212                 }
 213                 mark_buffer_dirty(bh);
 214                 if (overflow) {
 215                         block += count;
 216                         count = overflow;
 217                 }
 218         } while (overflow);
 219
 220 error_return:
 221         sb->s_dirt = 1;
 222         if (sbi->s_lvid_bh)
 223                 mark_buffer_dirty(sbi->s_lvid_bh);
 224         mutex_unlock(&sbi->s_alloc_mutex);
 225 }
 226
 227 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 228                                       struct inode *inode,
 229                                       struct udf_bitmap *bitmap,
 230                                       uint16_t partition, uint32_t first_block,
 231                                       uint32_t block_count)
 232 {
 233         struct udf_sb_info *sbi = UDF_SB(sb);
 234         int alloc_count = 0;
 235         int bit, block, block_group, group_start;
 236         int nr_groups, bitmap_nr;
 237         struct buffer_head *bh;
 238         __u32 part_len;
 239
 240         mutex_lock(&sbi->s_alloc_mutex);
 241         part_len = sbi->s_partmaps[partition].s_partition_len;
 242         if (first_block < 0 || first_block >= part_len)
 243                 goto out;
 244
 245         if (first_block + block_count > part_len)
 246                 block_count = part_len - first_block;
 247
 248         do {
 249                 nr_groups = udf_compute_nr_groups(sb, partition);
 250                 block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 251                 block_group = block >> (sb->s_blocksize_bits + 3);
 252                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 253
 254                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 255                 if (bitmap_nr < 0)
 256                         goto out;
 257                 bh = bitmap->s_block_bitmap[bitmap_nr];
 258
 259                 bit = block % (sb->s_blocksize << 3);
 260
 261                 while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 262                         if (!udf_test_bit(bit, bh->b_data))
 263                                 goto out;
 264                         else if (vfs_dq_prealloc_block(inode, 1))
 265                                 goto out;
 266                         else if (!udf_clear_bit(bit, bh->b_data)) {
 267                                 udf_debug("bit already cleared for block %d\n", bit);
 268                                 vfs_dq_free_block(inode, 1);
 269                                 goto out;
 270                         }
 271                         block_count--;
 272                         alloc_count++;
 273                         bit++;
 274                         block++;
 275                 }
 276                 mark_buffer_dirty(bh);
 277         } while (block_count > 0);
 278
 279 out:
 280         if (udf_add_free_space(sbi, partition, -alloc_count))
 281                 mark_buffer_dirty(sbi->s_lvid_bh);
 282         sb->s_dirt = 1;
 283         mutex_unlock(&sbi->s_alloc_mutex);
 284         return alloc_count;
 285 }
 286
 287 static int udf_bitmap_new_block(struct super_block *sb,
 288                                 struct inode *inode,
 289                                 struct udf_bitmap *bitmap, uint16_t partition,
 290                                 uint32_t goal, int *err)
 291 {
 292         struct udf_sb_info *sbi = UDF_SB(sb);
 293         int newbit, bit = 0, block, block_group, group_start;
 294         int end_goal, nr_groups, bitmap_nr, i;
 295         struct buffer_head *bh = NULL;
 296         char *ptr;
 297         int newblock = 0;
 298
 299         *err = -ENOSPC;
 300         mutex_lock(&sbi->s_alloc_mutex);
 301
 302 repeat:
 303         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 304                 goal = 0;
 305
 306         nr_groups = bitmap->s_nr_groups;
 307         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 308         block_group = block >> (sb->s_blocksize_bits + 3);
 309         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 310
 311         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 312         if (bitmap_nr < 0)
 313                 goto error_return;
 314         bh = bitmap->s_block_bitmap[bitmap_nr];
 315         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 316                       sb->s_blocksize - group_start);
 317
 318         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 319                 bit = block % (sb->s_blocksize << 3);
 320                 if (udf_test_bit(bit, bh->b_data))
 321                         goto got_block;
 322
 323                 end_goal = (bit + 63) & ~63;
 324                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 325                 if (bit < end_goal)
 326                         goto got_block;
 327
 328                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
 329                               sb->s_blocksize - ((bit + 7) >> 3));
 330                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 331                 if (newbit < sb->s_blocksize << 3) {
 332                         bit = newbit;
 333                         goto search_back;
 334                 }
 335
 336                 newbit = udf_find_next_one_bit(bh->b_data,
 337                                                sb->s_blocksize << 3, bit);
 338                 if (newbit < sb->s_blocksize << 3) {
 339                         bit = newbit;
 340                         goto got_block;
 341                 }
 342         }
 343
 344         for (i = 0; i < (nr_groups * 2); i++) {
 345                 block_group++;
 346                 if (block_group >= nr_groups)
 347                         block_group = 0;
 348                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 349
 350                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 351                 if (bitmap_nr < 0)
 352                         goto error_return;
 353                 bh = bitmap->s_block_bitmap[bitmap_nr];
 354                 if (i < nr_groups) {
 355                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 356                                       sb->s_blocksize - group_start);
 357                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 358                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 359                                 break;
 360                         }
 361                 } else {
 362                         bit = udf_find_next_one_bit((char *)bh->b_data,
 363                                                     sb->s_blocksize << 3,
 364                                                     group_start << 3);
 365                         if (bit < sb->s_blocksize << 3)
 366                                 break;
 367                 }
 368         }
 369         if (i >= (nr_groups * 2)) {
 370                 mutex_unlock(&sbi->s_alloc_mutex);
 371                 return newblock;
 372         }
 373         if (bit < sb->s_blocksize << 3)
 374                 goto search_back;
 375         else
 376                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
 377                                             group_start << 3);
 378         if (bit >= sb->s_blocksize << 3) {
 379                 mutex_unlock(&sbi->s_alloc_mutex);
 380                 return 0;
 381         }
 382
 383 search_back:
 384         i = 0;
 385         while (i < 7 && bit > (group_start << 3) &&
 386                udf_test_bit(bit - 1, bh->b_data)) {
 387                 ++i;
 388                 --bit;
 389         }
 390
 391 got_block:
 392
 393         /*
 394          * Check quota for allocation of this block.
 395          */
 396         if (inode && vfs_dq_alloc_block(inode, 1)) {
 397                 mutex_unlock(&sbi->s_alloc_mutex);
 398                 *err = -EDQUOT;
 399                 return 0;
 400         }
 401
 402         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 403                 (sizeof(struct spaceBitmapDesc) << 3);
 404
 405         if (!udf_clear_bit(bit, bh->b_data)) {
 406                 udf_debug("bit already cleared for block %d\n", bit);
 407                 goto repeat;
 408         }
 409
 410         mark_buffer_dirty(bh);
 411
 412         if (udf_add_free_space(sbi, partition, -1))
 413                 mark_buffer_dirty(sbi->s_lvid_bh);
 414         sb->s_dirt = 1;
 415         mutex_unlock(&sbi->s_alloc_mutex);
 416         *err = 0;
 417         return newblock;
 418
 419 error_return:
 420         *err = -EIO;
 421         mutex_unlock(&sbi->s_alloc_mutex);
 422         return 0;
 423 }
 424
 425 static void udf_table_free_blocks(struct super_block *sb,
 426                                   struct inode *inode,
 427                                   struct inode *table,
 428                                   struct kernel_lb_addr bloc, uint32_t offset,
 429                                   uint32_t count)
 430 {
 431         struct udf_sb_info *sbi = UDF_SB(sb);
 432         uint32_t start, end;
 433         uint32_t elen;
 434         struct kernel_lb_addr eloc;
 435         struct extent_position oepos, epos;
 436         int8_t etype;
 437         int i;
 438         struct udf_inode_info *iinfo;
 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         iinfo = UDF_I(table);
 452         /* We do this up front - There are some error conditions that
 453            could occure, but.. oh well */
 454         if (inode)
 455                 vfs_dq_free_block(inode, count);
 456         if (udf_add_free_space(sbi, sbi->s_partition, count))
 457                 mark_buffer_dirty(sbi->s_lvid_bh);
 458
 459         start = bloc.logicalBlockNum + offset;
 460         end = bloc.logicalBlockNum + offset + count - 1;
 461
 462         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 463         elen = 0;
 464         epos.block = oepos.block = iinfo->i_location;
 465         epos.bh = oepos.bh = NULL;
 466
 467         while (count &&
 468                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 469                 if (((eloc.logicalBlockNum +
 470                         (elen >> sb->s_blocksize_bits)) == start)) {
 471                         if ((0x3FFFFFFF - elen) <
 472                                         (count << sb->s_blocksize_bits)) {
 473                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 474                                                         sb->s_blocksize_bits);
 475                                 count -= tmp;
 476                                 start += tmp;
 477                                 elen = (etype << 30) |
 478                                         (0x40000000 - sb->s_blocksize);
 479                         } else {
 480                                 elen = (etype << 30) |
 481                                         (elen +
 482                                         (count << sb->s_blocksize_bits));
 483                                 start += count;
 484                                 count = 0;
 485                         }
 486                         udf_write_aext(table, &oepos, eloc, elen, 1);
 487                 } else if (eloc.logicalBlockNum == (end + 1)) {
 488                         if ((0x3FFFFFFF - elen) <
 489                                         (count << sb->s_blocksize_bits)) {
 490                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 491                                                 sb->s_blocksize_bits);
 492                                 count -= tmp;
 493                                 end -= tmp;
 494                                 eloc.logicalBlockNum -= tmp;
 495                                 elen = (etype << 30) |
 496                                         (0x40000000 - sb->s_blocksize);
 497                         } else {
 498                                 eloc.logicalBlockNum = start;
 499                                 elen = (etype << 30) |
 500                                         (elen +
 501                                         (count << sb->s_blocksize_bits));
 502                                 end -= count;
 503                                 count = 0;
 504                         }
 505                         udf_write_aext(table, &oepos, eloc, elen, 1);
 506                 }
 507
 508                 if (epos.bh != oepos.bh) {
 509                         i = -1;
 510                         oepos.block = epos.block;
 511                         brelse(oepos.bh);
 512                         get_bh(epos.bh);
 513                         oepos.bh = epos.bh;
 514                         oepos.offset = 0;
 515                 } else {
 516                         oepos.offset = epos.offset;
 517                 }
 518         }
 519
 520         if (count) {
 521                 /*
 522                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
 523                  * allocate a new block, and since we hold the super block
 524                  * lock already very bad things would happen :)
 525                  *
 526                  * We copy the behavior of udf_add_aext, but instead of
 527                  * trying to allocate a new block close to the existing one,
 528                  * we just steal a block from the extent we are trying to add.
 529                  *
 530                  * It would be nice if the blocks were close together, but it
 531                  * isn't required.
 532                  */
 533
 534                 int adsize;
 535                 struct short_ad *sad = NULL;
 536                 struct long_ad *lad = NULL;
 537                 struct allocExtDesc *aed;
 538
 539                 eloc.logicalBlockNum = start;
 540                 elen = EXT_RECORDED_ALLOCATED |
 541                         (count << sb->s_blocksize_bits);
 542
 543                 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 544                         adsize = sizeof(struct short_ad);
 545                 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 546                         adsize = sizeof(struct long_ad);
 547                 else {
 548                         brelse(oepos.bh);
 549                         brelse(epos.bh);
 550                         goto error_return;
 551                 }
 552
 553                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 554                         char *sptr, *dptr;
 555                         int loffset;
 556
 557                         brelse(oepos.bh);
 558                         oepos = epos;
 559
 560                         /* Steal a block from the extent being free'd */
 561                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 562                         eloc.logicalBlockNum++;
 563                         elen -= sb->s_blocksize;
 564
 565                         epos.bh = udf_tread(sb,
 566                                         udf_get_lb_pblock(sb, epos.block, 0));
 567                         if (!epos.bh) {
 568                                 brelse(oepos.bh);
 569                                 goto error_return;
 570                         }
 571                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 572                         aed->previousAllocExtLocation =
 573                                 cpu_to_le32(oepos.block.logicalBlockNum);
 574                         if (epos.offset + adsize > sb->s_blocksize) {
 575                                 loffset = epos.offset;
 576                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 577                                 sptr = iinfo->i_ext.i_data + epos.offset
 578                                                                 - adsize;
 579                                 dptr = epos.bh->b_data +
 580                                         sizeof(struct allocExtDesc);
 581                                 memcpy(dptr, sptr, adsize);
 582                                 epos.offset = sizeof(struct allocExtDesc) +
 583                                                 adsize;
 584                         } else {
 585                                 loffset = epos.offset + adsize;
 586                                 aed->lengthAllocDescs = cpu_to_le32(0);
 587                                 if (oepos.bh) {
 588                                         sptr = oepos.bh->b_data + epos.offset;
 589                                         aed = (struct allocExtDesc *)
 590                                                 oepos.bh->b_data;
 591                                         le32_add_cpu(&aed->lengthAllocDescs,
 592                                                         adsize);
 593                                 } else {
 594                                         sptr = iinfo->i_ext.i_data +
 595                                                                 epos.offset;
 596                                         iinfo->i_lenAlloc += adsize;
 597                                         mark_inode_dirty(table);
 598                                 }
 599                                 epos.offset = sizeof(struct allocExtDesc);
 600                         }
 601                         if (sbi->s_udfrev >= 0x0200)
 602                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 603                                             3, 1, epos.block.logicalBlockNum,
 604                                             sizeof(struct tag));
 605                         else
 606                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 607                                             2, 1, epos.block.logicalBlockNum,
 608                                             sizeof(struct tag));
 609
 610                         switch (iinfo->i_alloc_type) {
 611                         case ICBTAG_FLAG_AD_SHORT:
 612                                 sad = (struct short_ad *)sptr;
 613                                 sad->extLength = cpu_to_le32(
 614                                         EXT_NEXT_EXTENT_ALLOCDECS |
 615                                         sb->s_blocksize);
 616                                 sad->extPosition =
 617                                         cpu_to_le32(epos.block.logicalBlockNum);
 618                                 break;
 619                         case ICBTAG_FLAG_AD_LONG:
 620                                 lad = (struct long_ad *)sptr;
 621                                 lad->extLength = cpu_to_le32(
 622                                         EXT_NEXT_EXTENT_ALLOCDECS |
 623                                         sb->s_blocksize);
 624                                 lad->extLocation =
 625                                         cpu_to_lelb(epos.block);
 626                                 break;
 627                         }
 628                         if (oepos.bh) {
 629                                 udf_update_tag(oepos.bh->b_data, loffset);
 630                                 mark_buffer_dirty(oepos.bh);
 631                         } else {
 632                                 mark_inode_dirty(table);
 633                         }
 634                 }
 635
 636                 /* It's possible that stealing the block emptied the extent */
 637                 if (elen) {
 638                         udf_write_aext(table, &epos, eloc, elen, 1);
 639
 640                         if (!epos.bh) {
 641                                 iinfo->i_lenAlloc += adsize;
 642                                 mark_inode_dirty(table);
 643                         } else {
 644                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 645                                 le32_add_cpu(&aed->lengthAllocDescs, adsize);
 646                                 udf_update_tag(epos.bh->b_data, epos.offset);
 647                                 mark_buffer_dirty(epos.bh);
 648                         }
 649                 }
 650         }
 651
 652         brelse(epos.bh);
 653         brelse(oepos.bh);
 654
 655 error_return:
 656         sb->s_dirt = 1;
 657         mutex_unlock(&sbi->s_alloc_mutex);
 658         return;
 659 }
 660
 661 static int udf_table_prealloc_blocks(struct super_block *sb,
 662                                      struct inode *inode,
 663                                      struct inode *table, uint16_t partition,
 664                                      uint32_t first_block, uint32_t block_count)
 665 {
 666         struct udf_sb_info *sbi = UDF_SB(sb);
 667         int alloc_count = 0;
 668         uint32_t elen, adsize;
 669         struct kernel_lb_addr eloc;
 670         struct extent_position epos;
 671         int8_t etype = -1;
 672         struct udf_inode_info *iinfo;
 673
 674         if (first_block < 0 ||
 675                 first_block >= sbi->s_partmaps[partition].s_partition_len)
 676                 return 0;
 677
 678         iinfo = UDF_I(table);
 679         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 680                 adsize = sizeof(struct short_ad);
 681         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 682                 adsize = sizeof(struct long_ad);
 683         else
 684                 return 0;
 685
 686         mutex_lock(&sbi->s_alloc_mutex);
 687         epos.offset = sizeof(struct unallocSpaceEntry);
 688         epos.block = iinfo->i_location;
 689         epos.bh = NULL;
 690         eloc.logicalBlockNum = 0xFFFFFFFF;
 691
 692         while (first_block != eloc.logicalBlockNum &&
 693                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 694                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 695                           eloc.logicalBlockNum, elen, first_block);
 696                 ; /* empty loop body */
 697         }
 698
 699         if (first_block == eloc.logicalBlockNum) {
 700                 epos.offset -= adsize;
 701
 702                 alloc_count = (elen >> sb->s_blocksize_bits);
 703                 if (inode && vfs_dq_prealloc_block(inode,
 704                         alloc_count > block_count ? block_count : alloc_count))
 705                         alloc_count = 0;
 706                 else if (alloc_count > block_count) {
 707                         alloc_count = block_count;
 708                         eloc.logicalBlockNum += alloc_count;
 709                         elen -= (alloc_count << sb->s_blocksize_bits);
 710                         udf_write_aext(table, &epos, eloc,
 711                                         (etype << 30) | elen, 1);
 712                 } else
 713                         udf_delete_aext(table, epos, eloc,
 714                                         (etype << 30) | elen);
 715         } else {
 716                 alloc_count = 0;
 717         }
 718
 719         brelse(epos.bh);
 720
 721         if (alloc_count && udf_add_free_space(sbi, partition, -alloc_count)) {
 722                 mark_buffer_dirty(sbi->s_lvid_bh);
 723                 sb->s_dirt = 1;
 724         }
 725         mutex_unlock(&sbi->s_alloc_mutex);
 726         return alloc_count;
 727 }
 728
 729 static int udf_table_new_block(struct super_block *sb,
 730                                struct inode *inode,
 731                                struct inode *table, uint16_t partition,
 732                                uint32_t goal, int *err)
 733 {
 734         struct udf_sb_info *sbi = UDF_SB(sb);
 735         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 736         uint32_t newblock = 0, adsize;
 737         uint32_t elen, goal_elen = 0;
 738         struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 739         struct extent_position epos, goal_epos;
 740         int8_t etype;
 741         struct udf_inode_info *iinfo = UDF_I(table);
 742
 743         *err = -ENOSPC;
 744
 745         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 746                 adsize = sizeof(struct short_ad);
 747         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 748                 adsize = sizeof(struct 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 = iinfo->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 && vfs_dq_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                             struct 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 }