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   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,
 160                                    uint32_t offset,
 161                                    uint32_t count)
 162 {
 163         struct udf_sb_info *sbi = UDF_SB(sb);
 164         struct buffer_head *bh = NULL;
 165         struct udf_part_map *partmap;
 166         unsigned long block;
 167         unsigned long block_group;
 168         unsigned long bit;
 169         unsigned long i;
 170         int bitmap_nr;
 171         unsigned long overflow;
 172
 173         mutex_lock(&sbi->s_alloc_mutex);
 174         partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 175         if (bloc->logicalBlockNum < 0 ||
 176             (bloc->logicalBlockNum + count) >
 177                 partmap->s_partition_len) {
 178                 udf_debug("%d < %d || %d + %d > %d\n",
 179                           bloc->logicalBlockNum, 0, bloc->logicalBlockNum,
 180                           count, partmap->s_partition_len);
 181                 goto error_return;
 182         }
 183
 184         block = bloc->logicalBlockNum + offset +
 185                 (sizeof(struct spaceBitmapDesc) << 3);
 186
 187         do {
 188                 overflow = 0;
 189                 block_group = block >> (sb->s_blocksize_bits + 3);
 190                 bit = block % (sb->s_blocksize << 3);
 191
 192                 /*
 193                 * Check to see if we are freeing blocks across a group boundary.
 194                 */
 195                 if (bit + count > (sb->s_blocksize << 3)) {
 196                         overflow = bit + count - (sb->s_blocksize << 3);
 197                         count -= overflow;
 198                 }
 199                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 200                 if (bitmap_nr < 0)
 201                         goto error_return;
 202
 203                 bh = bitmap->s_block_bitmap[bitmap_nr];
 204                 for (i = 0; i < count; i++) {
 205                         if (udf_set_bit(bit + i, bh->b_data)) {
 206                                 udf_debug("bit %ld already set\n", bit + i);
 207                                 udf_debug("byte=%2x\n",
 208                                         ((char *)bh->b_data)[(bit + i) >> 3]);
 209                         } else {
 210                                 if (inode)
 211                                         vfs_dq_free_block(inode, 1);
 212                                 udf_add_free_space(sbi, sbi->s_partition, 1);
 213                         }
 214                 }
 215                 mark_buffer_dirty(bh);
 216                 if (overflow) {
 217                         block += count;
 218                         count = overflow;
 219                 }
 220         } while (overflow);
 221
 222 error_return:
 223         sb->s_dirt = 1;
 224         if (sbi->s_lvid_bh)
 225                 mark_buffer_dirty(sbi->s_lvid_bh);
 226         mutex_unlock(&sbi->s_alloc_mutex);
 227 }
 228
 229 static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 230                                       struct inode *inode,
 231                                       struct udf_bitmap *bitmap,
 232                                       uint16_t partition, uint32_t first_block,
 233                                       uint32_t block_count)
 234 {
 235         struct udf_sb_info *sbi = UDF_SB(sb);
 236         int alloc_count = 0;
 237         int bit, block, block_group, group_start;
 238         int nr_groups, bitmap_nr;
 239         struct buffer_head *bh;
 240         __u32 part_len;
 241
 242         mutex_lock(&sbi->s_alloc_mutex);
 243         part_len = sbi->s_partmaps[partition].s_partition_len;
 244         if (first_block < 0 || first_block >= part_len)
 245                 goto out;
 246
 247         if (first_block + block_count > part_len)
 248                 block_count = part_len - first_block;
 249
 250         do {
 251                 nr_groups = udf_compute_nr_groups(sb, partition);
 252                 block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 253                 block_group = block >> (sb->s_blocksize_bits + 3);
 254                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 255
 256                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 257                 if (bitmap_nr < 0)
 258                         goto out;
 259                 bh = bitmap->s_block_bitmap[bitmap_nr];
 260
 261                 bit = block % (sb->s_blocksize << 3);
 262
 263                 while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 264                         if (!udf_test_bit(bit, bh->b_data))
 265                                 goto out;
 266                         else if (vfs_dq_prealloc_block(inode, 1))
 267                                 goto out;
 268                         else if (!udf_clear_bit(bit, bh->b_data)) {
 269                                 udf_debug("bit already cleared for block %d\n", bit);
 270                                 vfs_dq_free_block(inode, 1);
 271                                 goto out;
 272                         }
 273                         block_count--;
 274                         alloc_count++;
 275                         bit++;
 276                         block++;
 277                 }
 278                 mark_buffer_dirty(bh);
 279         } while (block_count > 0);
 280
 281 out:
 282         if (udf_add_free_space(sbi, partition, -alloc_count))
 283                 mark_buffer_dirty(sbi->s_lvid_bh);
 284         sb->s_dirt = 1;
 285         mutex_unlock(&sbi->s_alloc_mutex);
 286         return alloc_count;
 287 }
 288
 289 static int udf_bitmap_new_block(struct super_block *sb,
 290                                 struct inode *inode,
 291                                 struct udf_bitmap *bitmap, uint16_t partition,
 292                                 uint32_t goal, int *err)
 293 {
 294         struct udf_sb_info *sbi = UDF_SB(sb);
 295         int newbit, bit = 0, block, block_group, group_start;
 296         int end_goal, nr_groups, bitmap_nr, i;
 297         struct buffer_head *bh = NULL;
 298         char *ptr;
 299         int newblock = 0;
 300
 301         *err = -ENOSPC;
 302         mutex_lock(&sbi->s_alloc_mutex);
 303
 304 repeat:
 305         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 306                 goal = 0;
 307
 308         nr_groups = bitmap->s_nr_groups;
 309         block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 310         block_group = block >> (sb->s_blocksize_bits + 3);
 311         group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 312
 313         bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 314         if (bitmap_nr < 0)
 315                 goto error_return;
 316         bh = bitmap->s_block_bitmap[bitmap_nr];
 317         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 318                       sb->s_blocksize - group_start);
 319
 320         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 321                 bit = block % (sb->s_blocksize << 3);
 322                 if (udf_test_bit(bit, bh->b_data))
 323                         goto got_block;
 324
 325                 end_goal = (bit + 63) & ~63;
 326                 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 327                 if (bit < end_goal)
 328                         goto got_block;
 329
 330                 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
 331                               sb->s_blocksize - ((bit + 7) >> 3));
 332                 newbit = (ptr - ((char *)bh->b_data)) << 3;
 333                 if (newbit < sb->s_blocksize << 3) {
 334                         bit = newbit;
 335                         goto search_back;
 336                 }
 337
 338                 newbit = udf_find_next_one_bit(bh->b_data,
 339                                                sb->s_blocksize << 3, bit);
 340                 if (newbit < sb->s_blocksize << 3) {
 341                         bit = newbit;
 342                         goto got_block;
 343                 }
 344         }
 345
 346         for (i = 0; i < (nr_groups * 2); i++) {
 347                 block_group++;
 348                 if (block_group >= nr_groups)
 349                         block_group = 0;
 350                 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 351
 352                 bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 353                 if (bitmap_nr < 0)
 354                         goto error_return;
 355                 bh = bitmap->s_block_bitmap[bitmap_nr];
 356                 if (i < nr_groups) {
 357                         ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 358                                       sb->s_blocksize - group_start);
 359                         if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 360                                 bit = (ptr - ((char *)bh->b_data)) << 3;
 361                                 break;
 362                         }
 363                 } else {
 364                         bit = udf_find_next_one_bit((char *)bh->b_data,
 365                                                     sb->s_blocksize << 3,
 366                                                     group_start << 3);
 367                         if (bit < sb->s_blocksize << 3)
 368                                 break;
 369                 }
 370         }
 371         if (i >= (nr_groups * 2)) {
 372                 mutex_unlock(&sbi->s_alloc_mutex);
 373                 return newblock;
 374         }
 375         if (bit < sb->s_blocksize << 3)
 376                 goto search_back;
 377         else
 378                 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
 379                                             group_start << 3);
 380         if (bit >= sb->s_blocksize << 3) {
 381                 mutex_unlock(&sbi->s_alloc_mutex);
 382                 return 0;
 383         }
 384
 385 search_back:
 386         i = 0;
 387         while (i < 7 && bit > (group_start << 3) &&
 388                udf_test_bit(bit - 1, bh->b_data)) {
 389                 ++i;
 390                 --bit;
 391         }
 392
 393 got_block:
 394
 395         /*
 396          * Check quota for allocation of this block.
 397          */
 398         if (inode && vfs_dq_alloc_block(inode, 1)) {
 399                 mutex_unlock(&sbi->s_alloc_mutex);
 400                 *err = -EDQUOT;
 401                 return 0;
 402         }
 403
 404         newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 405                 (sizeof(struct spaceBitmapDesc) << 3);
 406
 407         if (!udf_clear_bit(bit, bh->b_data)) {
 408                 udf_debug("bit already cleared for block %d\n", bit);
 409                 goto repeat;
 410         }
 411
 412         mark_buffer_dirty(bh);
 413
 414         if (udf_add_free_space(sbi, partition, -1))
 415                 mark_buffer_dirty(sbi->s_lvid_bh);
 416         sb->s_dirt = 1;
 417         mutex_unlock(&sbi->s_alloc_mutex);
 418         *err = 0;
 419         return newblock;
 420
 421 error_return:
 422         *err = -EIO;
 423         mutex_unlock(&sbi->s_alloc_mutex);
 424         return 0;
 425 }
 426
 427 static void udf_table_free_blocks(struct super_block *sb,
 428                                   struct inode *inode,
 429                                   struct inode *table,
 430                                   struct kernel_lb_addr *bloc,
 431                                   uint32_t offset,
 432                                   uint32_t count)
 433 {
 434         struct udf_sb_info *sbi = UDF_SB(sb);
 435         struct udf_part_map *partmap;
 436         uint32_t start, end;
 437         uint32_t elen;
 438         struct kernel_lb_addr eloc;
 439         struct extent_position oepos, epos;
 440         int8_t etype;
 441         int i;
 442         struct udf_inode_info *iinfo;
 443
 444         mutex_lock(&sbi->s_alloc_mutex);
 445         partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 446         if (bloc->logicalBlockNum < 0 ||
 447             (bloc->logicalBlockNum + count) >
 448                 partmap->s_partition_len) {
 449                 udf_debug("%d < %d || %d + %d > %d\n",
 450                           bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 451                           partmap->s_partition_len);
 452                 goto error_return;
 453         }
 454
 455         iinfo = UDF_I(table);
 456         /* We do this up front - There are some error conditions that
 457            could occure, but.. oh well */
 458         if (inode)
 459                 vfs_dq_free_block(inode, count);
 460         if (udf_add_free_space(sbi, sbi->s_partition, count))
 461                 mark_buffer_dirty(sbi->s_lvid_bh);
 462
 463         start = bloc->logicalBlockNum + offset;
 464         end = bloc->logicalBlockNum + offset + count - 1;
 465
 466         epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 467         elen = 0;
 468         epos.block = oepos.block = iinfo->i_location;
 469         epos.bh = oepos.bh = NULL;
 470
 471         while (count &&
 472                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 473                 if (((eloc.logicalBlockNum +
 474                         (elen >> sb->s_blocksize_bits)) == start)) {
 475                         if ((0x3FFFFFFF - elen) <
 476                                         (count << sb->s_blocksize_bits)) {
 477                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 478                                                         sb->s_blocksize_bits);
 479                                 count -= tmp;
 480                                 start += tmp;
 481                                 elen = (etype << 30) |
 482                                         (0x40000000 - sb->s_blocksize);
 483                         } else {
 484                                 elen = (etype << 30) |
 485                                         (elen +
 486                                         (count << sb->s_blocksize_bits));
 487                                 start += count;
 488                                 count = 0;
 489                         }
 490                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 491                 } else if (eloc.logicalBlockNum == (end + 1)) {
 492                         if ((0x3FFFFFFF - elen) <
 493                                         (count << sb->s_blocksize_bits)) {
 494                                 uint32_t tmp = ((0x3FFFFFFF - elen) >>
 495                                                 sb->s_blocksize_bits);
 496                                 count -= tmp;
 497                                 end -= tmp;
 498                                 eloc.logicalBlockNum -= tmp;
 499                                 elen = (etype << 30) |
 500                                         (0x40000000 - sb->s_blocksize);
 501                         } else {
 502                                 eloc.logicalBlockNum = start;
 503                                 elen = (etype << 30) |
 504                                         (elen +
 505                                         (count << sb->s_blocksize_bits));
 506                                 end -= count;
 507                                 count = 0;
 508                         }
 509                         udf_write_aext(table, &oepos, &eloc, elen, 1);
 510                 }
 511
 512                 if (epos.bh != oepos.bh) {
 513                         i = -1;
 514                         oepos.block = epos.block;
 515                         brelse(oepos.bh);
 516                         get_bh(epos.bh);
 517                         oepos.bh = epos.bh;
 518                         oepos.offset = 0;
 519                 } else {
 520                         oepos.offset = epos.offset;
 521                 }
 522         }
 523
 524         if (count) {
 525                 /*
 526                  * NOTE: we CANNOT use udf_add_aext here, as it can try to
 527                  * allocate a new block, and since we hold the super block
 528                  * lock already very bad things would happen :)
 529                  *
 530                  * We copy the behavior of udf_add_aext, but instead of
 531                  * trying to allocate a new block close to the existing one,
 532                  * we just steal a block from the extent we are trying to add.
 533                  *
 534                  * It would be nice if the blocks were close together, but it
 535                  * isn't required.
 536                  */
 537
 538                 int adsize;
 539                 struct short_ad *sad = NULL;
 540                 struct long_ad *lad = NULL;
 541                 struct allocExtDesc *aed;
 542
 543                 eloc.logicalBlockNum = start;
 544                 elen = EXT_RECORDED_ALLOCATED |
 545                         (count << sb->s_blocksize_bits);
 546
 547                 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 548                         adsize = sizeof(struct short_ad);
 549                 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 550                         adsize = sizeof(struct long_ad);
 551                 else {
 552                         brelse(oepos.bh);
 553                         brelse(epos.bh);
 554                         goto error_return;
 555                 }
 556
 557                 if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 558                         char *sptr, *dptr;
 559                         int loffset;
 560
 561                         brelse(oepos.bh);
 562                         oepos = epos;
 563
 564                         /* Steal a block from the extent being free'd */
 565                         epos.block.logicalBlockNum = eloc.logicalBlockNum;
 566                         eloc.logicalBlockNum++;
 567                         elen -= sb->s_blocksize;
 568
 569                         epos.bh = udf_tread(sb,
 570                                         udf_get_lb_pblock(sb, &epos.block, 0));
 571                         if (!epos.bh) {
 572                                 brelse(oepos.bh);
 573                                 goto error_return;
 574                         }
 575                         aed = (struct allocExtDesc *)(epos.bh->b_data);
 576                         aed->previousAllocExtLocation =
 577                                 cpu_to_le32(oepos.block.logicalBlockNum);
 578                         if (epos.offset + adsize > sb->s_blocksize) {
 579                                 loffset = epos.offset;
 580                                 aed->lengthAllocDescs = cpu_to_le32(adsize);
 581                                 sptr = iinfo->i_ext.i_data + epos.offset
 582                                                                 - adsize;
 583                                 dptr = epos.bh->b_data +
 584                                         sizeof(struct allocExtDesc);
 585                                 memcpy(dptr, sptr, adsize);
 586                                 epos.offset = sizeof(struct allocExtDesc) +
 587                                                 adsize;
 588                         } else {
 589                                 loffset = epos.offset + adsize;
 590                                 aed->lengthAllocDescs = cpu_to_le32(0);
 591                                 if (oepos.bh) {
 592                                         sptr = oepos.bh->b_data + epos.offset;
 593                                         aed = (struct allocExtDesc *)
 594                                                 oepos.bh->b_data;
 595                                         le32_add_cpu(&aed->lengthAllocDescs,
 596                                                         adsize);
 597                                 } else {
 598                                         sptr = iinfo->i_ext.i_data +
 599                                                                 epos.offset;
 600                                         iinfo->i_lenAlloc += adsize;
 601                                         mark_inode_dirty(table);
 602                                 }
 603                                 epos.offset = sizeof(struct allocExtDesc);
 604                         }
 605                         if (sbi->s_udfrev >= 0x0200)
 606                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 607                                             3, 1, epos.block.logicalBlockNum,
 608                                             sizeof(struct tag));
 609                         else
 610                                 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 611                                             2, 1, epos.block.logicalBlockNum,
 612                                             sizeof(struct tag));
 613
 614                         switch (iinfo->i_alloc_type) {
 615                         case ICBTAG_FLAG_AD_SHORT:
 616                                 sad = (struct short_ad *)sptr;
 617                                 sad->extLength = cpu_to_le32(
 618                                         EXT_NEXT_EXTENT_ALLOCDECS |
 619                                         sb->s_blocksize);
 620                                 sad->extPosition =
 621                                         cpu_to_le32(epos.block.logicalBlockNum);
 622                                 break;
 623                         case ICBTAG_FLAG_AD_LONG:
 624                                 lad = (struct long_ad *)sptr;
 625                                 lad->extLength = cpu_to_le32(
 626                                         EXT_NEXT_EXTENT_ALLOCDECS |
 627                                         sb->s_blocksize);
 628                                 lad->extLocation =
 629                                         cpu_to_lelb(epos.block);
 630                                 break;
 631                         }
 632                         if (oepos.bh) {
 633                                 udf_update_tag(oepos.bh->b_data, loffset);
 634                                 mark_buffer_dirty(oepos.bh);
 635                         } else {
 636                                 mark_inode_dirty(table);
 637                         }
 638                 }
 639
 640                 /* It's possible that stealing the block emptied the extent */
 641                 if (elen) {
 642                         udf_write_aext(table, &epos, &eloc, elen, 1);
 643
 644                         if (!epos.bh) {
 645                                 iinfo->i_lenAlloc += adsize;
 646                                 mark_inode_dirty(table);
 647                         } else {
 648                                 aed = (struct allocExtDesc *)epos.bh->b_data;
 649                                 le32_add_cpu(&aed->lengthAllocDescs, adsize);
 650                                 udf_update_tag(epos.bh->b_data, epos.offset);
 651                                 mark_buffer_dirty(epos.bh);
 652                         }
 653                 }
 654         }
 655
 656         brelse(epos.bh);
 657         brelse(oepos.bh);
 658
 659 error_return:
 660         sb->s_dirt = 1;
 661         mutex_unlock(&sbi->s_alloc_mutex);
 662         return;
 663 }
 664
 665 static int udf_table_prealloc_blocks(struct super_block *sb,
 666                                      struct inode *inode,
 667                                      struct inode *table, uint16_t partition,
 668                                      uint32_t first_block, uint32_t block_count)
 669 {
 670         struct udf_sb_info *sbi = UDF_SB(sb);
 671         int alloc_count = 0;
 672         uint32_t elen, adsize;
 673         struct kernel_lb_addr eloc;
 674         struct extent_position epos;
 675         int8_t etype = -1;
 676         struct udf_inode_info *iinfo;
 677
 678         if (first_block < 0 ||
 679                 first_block >= sbi->s_partmaps[partition].s_partition_len)
 680                 return 0;
 681
 682         iinfo = UDF_I(table);
 683         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 684                 adsize = sizeof(struct short_ad);
 685         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 686                 adsize = sizeof(struct long_ad);
 687         else
 688                 return 0;
 689
 690         mutex_lock(&sbi->s_alloc_mutex);
 691         epos.offset = sizeof(struct unallocSpaceEntry);
 692         epos.block = iinfo->i_location;
 693         epos.bh = NULL;
 694         eloc.logicalBlockNum = 0xFFFFFFFF;
 695
 696         while (first_block != eloc.logicalBlockNum &&
 697                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 698                 udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 699                           eloc.logicalBlockNum, elen, first_block);
 700                 ; /* empty loop body */
 701         }
 702
 703         if (first_block == eloc.logicalBlockNum) {
 704                 epos.offset -= adsize;
 705
 706                 alloc_count = (elen >> sb->s_blocksize_bits);
 707                 if (inode && vfs_dq_prealloc_block(inode,
 708                         alloc_count > block_count ? block_count : alloc_count))
 709                         alloc_count = 0;
 710                 else if (alloc_count > block_count) {
 711                         alloc_count = block_count;
 712                         eloc.logicalBlockNum += alloc_count;
 713                         elen -= (alloc_count << sb->s_blocksize_bits);
 714                         udf_write_aext(table, &epos, &eloc,
 715                                         (etype << 30) | elen, 1);
 716                 } else
 717                         udf_delete_aext(table, epos, eloc,
 718                                         (etype << 30) | elen);
 719         } else {
 720                 alloc_count = 0;
 721         }
 722
 723         brelse(epos.bh);
 724
 725         if (alloc_count && udf_add_free_space(sbi, partition, -alloc_count)) {
 726                 mark_buffer_dirty(sbi->s_lvid_bh);
 727                 sb->s_dirt = 1;
 728         }
 729         mutex_unlock(&sbi->s_alloc_mutex);
 730         return alloc_count;
 731 }
 732
 733 static int udf_table_new_block(struct super_block *sb,
 734                                struct inode *inode,
 735                                struct inode *table, uint16_t partition,
 736                                uint32_t goal, int *err)
 737 {
 738         struct udf_sb_info *sbi = UDF_SB(sb);
 739         uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 740         uint32_t newblock = 0, adsize;
 741         uint32_t elen, goal_elen = 0;
 742         struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 743         struct extent_position epos, goal_epos;
 744         int8_t etype;
 745         struct udf_inode_info *iinfo = UDF_I(table);
 746
 747         *err = -ENOSPC;
 748
 749         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 750                 adsize = sizeof(struct short_ad);
 751         else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 752                 adsize = sizeof(struct long_ad);
 753         else
 754                 return newblock;
 755
 756         mutex_lock(&sbi->s_alloc_mutex);
 757         if (goal < 0 || goal >= sbi->s_partmaps[partition].s_partition_len)
 758                 goal = 0;
 759
 760         /* We search for the closest matching block to goal. If we find
 761            a exact hit, we stop. Otherwise we keep going till we run out
 762            of extents. We store the buffer_head, bloc, and extoffset
 763            of the current closest match and use that when we are done.
 764          */
 765         epos.offset = sizeof(struct unallocSpaceEntry);
 766         epos.block = iinfo->i_location;
 767         epos.bh = goal_epos.bh = NULL;
 768
 769         while (spread &&
 770                (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 771                 if (goal >= eloc.logicalBlockNum) {
 772                         if (goal < eloc.logicalBlockNum +
 773                                         (elen >> sb->s_blocksize_bits))
 774                                 nspread = 0;
 775                         else
 776                                 nspread = goal - eloc.logicalBlockNum -
 777                                         (elen >> sb->s_blocksize_bits);
 778                 } else {
 779                         nspread = eloc.logicalBlockNum - goal;
 780                 }
 781
 782                 if (nspread < spread) {
 783                         spread = nspread;
 784                         if (goal_epos.bh != epos.bh) {
 785                                 brelse(goal_epos.bh);
 786                                 goal_epos.bh = epos.bh;
 787                                 get_bh(goal_epos.bh);
 788                         }
 789                         goal_epos.block = epos.block;
 790                         goal_epos.offset = epos.offset - adsize;
 791                         goal_eloc = eloc;
 792                         goal_elen = (etype << 30) | elen;
 793                 }
 794         }
 795
 796         brelse(epos.bh);
 797
 798         if (spread == 0xFFFFFFFF) {
 799                 brelse(goal_epos.bh);
 800                 mutex_unlock(&sbi->s_alloc_mutex);
 801                 return 0;
 802         }
 803
 804         /* Only allocate blocks from the beginning of the extent.
 805            That way, we only delete (empty) extents, never have to insert an
 806            extent because of splitting */
 807         /* This works, but very poorly.... */
 808
 809         newblock = goal_eloc.logicalBlockNum;
 810         goal_eloc.logicalBlockNum++;
 811         goal_elen -= sb->s_blocksize;
 812
 813         if (inode && vfs_dq_alloc_block(inode, 1)) {
 814                 brelse(goal_epos.bh);
 815                 mutex_unlock(&sbi->s_alloc_mutex);
 816                 *err = -EDQUOT;
 817                 return 0;
 818         }
 819
 820         if (goal_elen)
 821                 udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
 822         else
 823                 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 824         brelse(goal_epos.bh);
 825
 826         if (udf_add_free_space(sbi, partition, -1))
 827                 mark_buffer_dirty(sbi->s_lvid_bh);
 828
 829         sb->s_dirt = 1;
 830         mutex_unlock(&sbi->s_alloc_mutex);
 831         *err = 0;
 832         return newblock;
 833 }
 834
 835 void udf_free_blocks(struct super_block *sb, struct inode *inode,
 836                      struct kernel_lb_addr *bloc, uint32_t offset,
 837                      uint32_t count)
 838 {
 839         uint16_t partition = bloc->partitionReferenceNum;
 840         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 841
 842         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 843                 udf_bitmap_free_blocks(sb, inode, map->s_uspace.s_bitmap,
 844                                        bloc, offset, count);
 845         } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 846                 udf_table_free_blocks(sb, inode, map->s_uspace.s_table,
 847                                       bloc, offset, count);
 848         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 849                 udf_bitmap_free_blocks(sb, inode, map->s_fspace.s_bitmap,
 850                                        bloc, offset, count);
 851         } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 852                 udf_table_free_blocks(sb, inode, map->s_fspace.s_table,
 853                                       bloc, offset, count);
 854         }
 855 }
 856
 857 inline int udf_prealloc_blocks(struct super_block *sb,
 858                                struct inode *inode,
 859                                uint16_t partition, uint32_t first_block,
 860                                uint32_t block_count)
 861 {
 862         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 863
 864         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 865                 return udf_bitmap_prealloc_blocks(sb, inode,
 866                                                   map->s_uspace.s_bitmap,
 867                                                   partition, first_block,
 868                                                   block_count);
 869         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 870                 return udf_table_prealloc_blocks(sb, inode,
 871                                                  map->s_uspace.s_table,
 872                                                  partition, first_block,
 873                                                  block_count);
 874         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 875                 return udf_bitmap_prealloc_blocks(sb, inode,
 876                                                   map->s_fspace.s_bitmap,
 877                                                   partition, first_block,
 878                                                   block_count);
 879         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 880                 return udf_table_prealloc_blocks(sb, inode,
 881                                                  map->s_fspace.s_table,
 882                                                  partition, first_block,
 883                                                  block_count);
 884         else
 885                 return 0;
 886 }
 887
 888 inline int udf_new_block(struct super_block *sb,
 889                          struct inode *inode,
 890                          uint16_t partition, uint32_t goal, int *err)
 891 {
 892         struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 893
 894         if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 895                 return udf_bitmap_new_block(sb, inode,
 896                                            map->s_uspace.s_bitmap,
 897                                            partition, goal, err);
 898         else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 899                 return udf_table_new_block(sb, inode,
 900                                            map->s_uspace.s_table,
 901                                            partition, goal, err);
 902         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 903                 return udf_bitmap_new_block(sb, inode,
 904                                             map->s_fspace.s_bitmap,
 905                                             partition, goal, err);
 906         else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 907                 return udf_table_new_block(sb, inode,
 908                                            map->s_fspace.s_table,
 909                                            partition, goal, err);
 910         else {
 911                 *err = -EIO;
 912                 return 0;
 913         }
 914 }