linux/fs/udf/balloc.c
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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
  45static 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);
  75found_first:
  76        tmp &= ~0UL >> (BITS_PER_LONG - size);
  77found_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
  84static 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
 103static 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
 126static 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
 143static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
 144{
 145        struct udf_sb_info *sbi = UDF_SB(sb);
 146        struct logicalVolIntegrityDesc *lvid;
 147
 148        if (!sbi->s_lvid_bh)
 149                return;
 150
 151        lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
 152        le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
 153        udf_updated_lvid(sb);
 154}
 155
 156static 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(sb, 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
 222error_return:
 223        mutex_unlock(&sbi->s_alloc_mutex);
 224}
 225
 226static int udf_bitmap_prealloc_blocks(struct super_block *sb,
 227                                      struct inode *inode,
 228                                      struct udf_bitmap *bitmap,
 229                                      uint16_t partition, uint32_t first_block,
 230                                      uint32_t block_count)
 231{
 232        struct udf_sb_info *sbi = UDF_SB(sb);
 233        int alloc_count = 0;
 234        int bit, block, block_group, group_start;
 235        int nr_groups, bitmap_nr;
 236        struct buffer_head *bh;
 237        __u32 part_len;
 238
 239        mutex_lock(&sbi->s_alloc_mutex);
 240        part_len = sbi->s_partmaps[partition].s_partition_len;
 241        if (first_block >= part_len)
 242                goto out;
 243
 244        if (first_block + block_count > part_len)
 245                block_count = part_len - first_block;
 246
 247        do {
 248                nr_groups = udf_compute_nr_groups(sb, partition);
 249                block = first_block + (sizeof(struct spaceBitmapDesc) << 3);
 250                block_group = block >> (sb->s_blocksize_bits + 3);
 251                group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 252
 253                bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 254                if (bitmap_nr < 0)
 255                        goto out;
 256                bh = bitmap->s_block_bitmap[bitmap_nr];
 257
 258                bit = block % (sb->s_blocksize << 3);
 259
 260                while (bit < (sb->s_blocksize << 3) && block_count > 0) {
 261                        if (!udf_test_bit(bit, bh->b_data))
 262                                goto out;
 263                        else if (vfs_dq_prealloc_block(inode, 1))
 264                                goto out;
 265                        else if (!udf_clear_bit(bit, bh->b_data)) {
 266                                udf_debug("bit already cleared for block %d\n", bit);
 267                                vfs_dq_free_block(inode, 1);
 268                                goto out;
 269                        }
 270                        block_count--;
 271                        alloc_count++;
 272                        bit++;
 273                        block++;
 274                }
 275                mark_buffer_dirty(bh);
 276        } while (block_count > 0);
 277
 278out:
 279        udf_add_free_space(sb, partition, -alloc_count);
 280        mutex_unlock(&sbi->s_alloc_mutex);
 281        return alloc_count;
 282}
 283
 284static int udf_bitmap_new_block(struct super_block *sb,
 285                                struct inode *inode,
 286                                struct udf_bitmap *bitmap, uint16_t partition,
 287                                uint32_t goal, int *err)
 288{
 289        struct udf_sb_info *sbi = UDF_SB(sb);
 290        int newbit, bit = 0, block, block_group, group_start;
 291        int end_goal, nr_groups, bitmap_nr, i;
 292        struct buffer_head *bh = NULL;
 293        char *ptr;
 294        int newblock = 0;
 295
 296        *err = -ENOSPC;
 297        mutex_lock(&sbi->s_alloc_mutex);
 298
 299repeat:
 300        if (goal >= sbi->s_partmaps[partition].s_partition_len)
 301                goal = 0;
 302
 303        nr_groups = bitmap->s_nr_groups;
 304        block = goal + (sizeof(struct spaceBitmapDesc) << 3);
 305        block_group = block >> (sb->s_blocksize_bits + 3);
 306        group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 307
 308        bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 309        if (bitmap_nr < 0)
 310                goto error_return;
 311        bh = bitmap->s_block_bitmap[bitmap_nr];
 312        ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 313                      sb->s_blocksize - group_start);
 314
 315        if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 316                bit = block % (sb->s_blocksize << 3);
 317                if (udf_test_bit(bit, bh->b_data))
 318                        goto got_block;
 319
 320                end_goal = (bit + 63) & ~63;
 321                bit = udf_find_next_one_bit(bh->b_data, end_goal, bit);
 322                if (bit < end_goal)
 323                        goto got_block;
 324
 325                ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF,
 326                              sb->s_blocksize - ((bit + 7) >> 3));
 327                newbit = (ptr - ((char *)bh->b_data)) << 3;
 328                if (newbit < sb->s_blocksize << 3) {
 329                        bit = newbit;
 330                        goto search_back;
 331                }
 332
 333                newbit = udf_find_next_one_bit(bh->b_data,
 334                                               sb->s_blocksize << 3, bit);
 335                if (newbit < sb->s_blocksize << 3) {
 336                        bit = newbit;
 337                        goto got_block;
 338                }
 339        }
 340
 341        for (i = 0; i < (nr_groups * 2); i++) {
 342                block_group++;
 343                if (block_group >= nr_groups)
 344                        block_group = 0;
 345                group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc);
 346
 347                bitmap_nr = load_block_bitmap(sb, bitmap, block_group);
 348                if (bitmap_nr < 0)
 349                        goto error_return;
 350                bh = bitmap->s_block_bitmap[bitmap_nr];
 351                if (i < nr_groups) {
 352                        ptr = memscan((char *)bh->b_data + group_start, 0xFF,
 353                                      sb->s_blocksize - group_start);
 354                        if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) {
 355                                bit = (ptr - ((char *)bh->b_data)) << 3;
 356                                break;
 357                        }
 358                } else {
 359                        bit = udf_find_next_one_bit((char *)bh->b_data,
 360                                                    sb->s_blocksize << 3,
 361                                                    group_start << 3);
 362                        if (bit < sb->s_blocksize << 3)
 363                                break;
 364                }
 365        }
 366        if (i >= (nr_groups * 2)) {
 367                mutex_unlock(&sbi->s_alloc_mutex);
 368                return newblock;
 369        }
 370        if (bit < sb->s_blocksize << 3)
 371                goto search_back;
 372        else
 373                bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3,
 374                                            group_start << 3);
 375        if (bit >= sb->s_blocksize << 3) {
 376                mutex_unlock(&sbi->s_alloc_mutex);
 377                return 0;
 378        }
 379
 380search_back:
 381        i = 0;
 382        while (i < 7 && bit > (group_start << 3) &&
 383               udf_test_bit(bit - 1, bh->b_data)) {
 384                ++i;
 385                --bit;
 386        }
 387
 388got_block:
 389
 390        /*
 391         * Check quota for allocation of this block.
 392         */
 393        if (inode && vfs_dq_alloc_block(inode, 1)) {
 394                mutex_unlock(&sbi->s_alloc_mutex);
 395                *err = -EDQUOT;
 396                return 0;
 397        }
 398
 399        newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) -
 400                (sizeof(struct spaceBitmapDesc) << 3);
 401
 402        if (!udf_clear_bit(bit, bh->b_data)) {
 403                udf_debug("bit already cleared for block %d\n", bit);
 404                goto repeat;
 405        }
 406
 407        mark_buffer_dirty(bh);
 408
 409        udf_add_free_space(sb, partition, -1);
 410        mutex_unlock(&sbi->s_alloc_mutex);
 411        *err = 0;
 412        return newblock;
 413
 414error_return:
 415        *err = -EIO;
 416        mutex_unlock(&sbi->s_alloc_mutex);
 417        return 0;
 418}
 419
 420static void udf_table_free_blocks(struct super_block *sb,
 421                                  struct inode *inode,
 422                                  struct inode *table,
 423                                  struct kernel_lb_addr *bloc,
 424                                  uint32_t offset,
 425                                  uint32_t count)
 426{
 427        struct udf_sb_info *sbi = UDF_SB(sb);
 428        struct udf_part_map *partmap;
 429        uint32_t start, end;
 430        uint32_t elen;
 431        struct kernel_lb_addr eloc;
 432        struct extent_position oepos, epos;
 433        int8_t etype;
 434        int i;
 435        struct udf_inode_info *iinfo;
 436
 437        mutex_lock(&sbi->s_alloc_mutex);
 438        partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
 439        if (bloc->logicalBlockNum < 0 ||
 440            (bloc->logicalBlockNum + count) >
 441                partmap->s_partition_len) {
 442                udf_debug("%d < %d || %d + %d > %d\n",
 443                          bloc.logicalBlockNum, 0, bloc.logicalBlockNum, count,
 444                          partmap->s_partition_len);
 445                goto error_return;
 446        }
 447
 448        iinfo = UDF_I(table);
 449        /* We do this up front - There are some error conditions that
 450           could occure, but.. oh well */
 451        if (inode)
 452                vfs_dq_free_block(inode, count);
 453        udf_add_free_space(sb, sbi->s_partition, count);
 454
 455        start = bloc->logicalBlockNum + offset;
 456        end = bloc->logicalBlockNum + offset + count - 1;
 457
 458        epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry);
 459        elen = 0;
 460        epos.block = oepos.block = iinfo->i_location;
 461        epos.bh = oepos.bh = NULL;
 462
 463        while (count &&
 464               (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 465                if (((eloc.logicalBlockNum +
 466                        (elen >> sb->s_blocksize_bits)) == start)) {
 467                        if ((0x3FFFFFFF - elen) <
 468                                        (count << sb->s_blocksize_bits)) {
 469                                uint32_t tmp = ((0x3FFFFFFF - elen) >>
 470                                                        sb->s_blocksize_bits);
 471                                count -= tmp;
 472                                start += tmp;
 473                                elen = (etype << 30) |
 474                                        (0x40000000 - sb->s_blocksize);
 475                        } else {
 476                                elen = (etype << 30) |
 477                                        (elen +
 478                                        (count << sb->s_blocksize_bits));
 479                                start += count;
 480                                count = 0;
 481                        }
 482                        udf_write_aext(table, &oepos, &eloc, elen, 1);
 483                } else if (eloc.logicalBlockNum == (end + 1)) {
 484                        if ((0x3FFFFFFF - elen) <
 485                                        (count << sb->s_blocksize_bits)) {
 486                                uint32_t tmp = ((0x3FFFFFFF - elen) >>
 487                                                sb->s_blocksize_bits);
 488                                count -= tmp;
 489                                end -= tmp;
 490                                eloc.logicalBlockNum -= tmp;
 491                                elen = (etype << 30) |
 492                                        (0x40000000 - sb->s_blocksize);
 493                        } else {
 494                                eloc.logicalBlockNum = start;
 495                                elen = (etype << 30) |
 496                                        (elen +
 497                                        (count << sb->s_blocksize_bits));
 498                                end -= count;
 499                                count = 0;
 500                        }
 501                        udf_write_aext(table, &oepos, &eloc, elen, 1);
 502                }
 503
 504                if (epos.bh != oepos.bh) {
 505                        i = -1;
 506                        oepos.block = epos.block;
 507                        brelse(oepos.bh);
 508                        get_bh(epos.bh);
 509                        oepos.bh = epos.bh;
 510                        oepos.offset = 0;
 511                } else {
 512                        oepos.offset = epos.offset;
 513                }
 514        }
 515
 516        if (count) {
 517                /*
 518                 * NOTE: we CANNOT use udf_add_aext here, as it can try to
 519                 * allocate a new block, and since we hold the super block
 520                 * lock already very bad things would happen :)
 521                 *
 522                 * We copy the behavior of udf_add_aext, but instead of
 523                 * trying to allocate a new block close to the existing one,
 524                 * we just steal a block from the extent we are trying to add.
 525                 *
 526                 * It would be nice if the blocks were close together, but it
 527                 * isn't required.
 528                 */
 529
 530                int adsize;
 531                struct short_ad *sad = NULL;
 532                struct long_ad *lad = NULL;
 533                struct allocExtDesc *aed;
 534
 535                eloc.logicalBlockNum = start;
 536                elen = EXT_RECORDED_ALLOCATED |
 537                        (count << sb->s_blocksize_bits);
 538
 539                if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 540                        adsize = sizeof(struct short_ad);
 541                else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 542                        adsize = sizeof(struct long_ad);
 543                else {
 544                        brelse(oepos.bh);
 545                        brelse(epos.bh);
 546                        goto error_return;
 547                }
 548
 549                if (epos.offset + (2 * adsize) > sb->s_blocksize) {
 550                        char *sptr, *dptr;
 551                        int loffset;
 552
 553                        brelse(oepos.bh);
 554                        oepos = epos;
 555
 556                        /* Steal a block from the extent being free'd */
 557                        epos.block.logicalBlockNum = eloc.logicalBlockNum;
 558                        eloc.logicalBlockNum++;
 559                        elen -= sb->s_blocksize;
 560
 561                        epos.bh = udf_tread(sb,
 562                                        udf_get_lb_pblock(sb, &epos.block, 0));
 563                        if (!epos.bh) {
 564                                brelse(oepos.bh);
 565                                goto error_return;
 566                        }
 567                        aed = (struct allocExtDesc *)(epos.bh->b_data);
 568                        aed->previousAllocExtLocation =
 569                                cpu_to_le32(oepos.block.logicalBlockNum);
 570                        if (epos.offset + adsize > sb->s_blocksize) {
 571                                loffset = epos.offset;
 572                                aed->lengthAllocDescs = cpu_to_le32(adsize);
 573                                sptr = iinfo->i_ext.i_data + epos.offset
 574                                                                - adsize;
 575                                dptr = epos.bh->b_data +
 576                                        sizeof(struct allocExtDesc);
 577                                memcpy(dptr, sptr, adsize);
 578                                epos.offset = sizeof(struct allocExtDesc) +
 579                                                adsize;
 580                        } else {
 581                                loffset = epos.offset + adsize;
 582                                aed->lengthAllocDescs = cpu_to_le32(0);
 583                                if (oepos.bh) {
 584                                        sptr = oepos.bh->b_data + epos.offset;
 585                                        aed = (struct allocExtDesc *)
 586                                                oepos.bh->b_data;
 587                                        le32_add_cpu(&aed->lengthAllocDescs,
 588                                                        adsize);
 589                                } else {
 590                                        sptr = iinfo->i_ext.i_data +
 591                                                                epos.offset;
 592                                        iinfo->i_lenAlloc += adsize;
 593                                        mark_inode_dirty(table);
 594                                }
 595                                epos.offset = sizeof(struct allocExtDesc);
 596                        }
 597                        if (sbi->s_udfrev >= 0x0200)
 598                                udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 599                                            3, 1, epos.block.logicalBlockNum,
 600                                            sizeof(struct tag));
 601                        else
 602                                udf_new_tag(epos.bh->b_data, TAG_IDENT_AED,
 603                                            2, 1, epos.block.logicalBlockNum,
 604                                            sizeof(struct tag));
 605
 606                        switch (iinfo->i_alloc_type) {
 607                        case ICBTAG_FLAG_AD_SHORT:
 608                                sad = (struct short_ad *)sptr;
 609                                sad->extLength = cpu_to_le32(
 610                                        EXT_NEXT_EXTENT_ALLOCDECS |
 611                                        sb->s_blocksize);
 612                                sad->extPosition =
 613                                        cpu_to_le32(epos.block.logicalBlockNum);
 614                                break;
 615                        case ICBTAG_FLAG_AD_LONG:
 616                                lad = (struct long_ad *)sptr;
 617                                lad->extLength = cpu_to_le32(
 618                                        EXT_NEXT_EXTENT_ALLOCDECS |
 619                                        sb->s_blocksize);
 620                                lad->extLocation =
 621                                        cpu_to_lelb(epos.block);
 622                                break;
 623                        }
 624                        if (oepos.bh) {
 625                                udf_update_tag(oepos.bh->b_data, loffset);
 626                                mark_buffer_dirty(oepos.bh);
 627                        } else {
 628                                mark_inode_dirty(table);
 629                        }
 630                }
 631
 632                /* It's possible that stealing the block emptied the extent */
 633                if (elen) {
 634                        udf_write_aext(table, &epos, &eloc, elen, 1);
 635
 636                        if (!epos.bh) {
 637                                iinfo->i_lenAlloc += adsize;
 638                                mark_inode_dirty(table);
 639                        } else {
 640                                aed = (struct allocExtDesc *)epos.bh->b_data;
 641                                le32_add_cpu(&aed->lengthAllocDescs, adsize);
 642                                udf_update_tag(epos.bh->b_data, epos.offset);
 643                                mark_buffer_dirty(epos.bh);
 644                        }
 645                }
 646        }
 647
 648        brelse(epos.bh);
 649        brelse(oepos.bh);
 650
 651error_return:
 652        mutex_unlock(&sbi->s_alloc_mutex);
 653        return;
 654}
 655
 656static int udf_table_prealloc_blocks(struct super_block *sb,
 657                                     struct inode *inode,
 658                                     struct inode *table, uint16_t partition,
 659                                     uint32_t first_block, uint32_t block_count)
 660{
 661        struct udf_sb_info *sbi = UDF_SB(sb);
 662        int alloc_count = 0;
 663        uint32_t elen, adsize;
 664        struct kernel_lb_addr eloc;
 665        struct extent_position epos;
 666        int8_t etype = -1;
 667        struct udf_inode_info *iinfo;
 668
 669        if (first_block >= sbi->s_partmaps[partition].s_partition_len)
 670                return 0;
 671
 672        iinfo = UDF_I(table);
 673        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 674                adsize = sizeof(struct short_ad);
 675        else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 676                adsize = sizeof(struct long_ad);
 677        else
 678                return 0;
 679
 680        mutex_lock(&sbi->s_alloc_mutex);
 681        epos.offset = sizeof(struct unallocSpaceEntry);
 682        epos.block = iinfo->i_location;
 683        epos.bh = NULL;
 684        eloc.logicalBlockNum = 0xFFFFFFFF;
 685
 686        while (first_block != eloc.logicalBlockNum &&
 687               (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 688                udf_debug("eloc=%d, elen=%d, first_block=%d\n",
 689                          eloc.logicalBlockNum, elen, first_block);
 690                ; /* empty loop body */
 691        }
 692
 693        if (first_block == eloc.logicalBlockNum) {
 694                epos.offset -= adsize;
 695
 696                alloc_count = (elen >> sb->s_blocksize_bits);
 697                if (inode && vfs_dq_prealloc_block(inode,
 698                        alloc_count > block_count ? block_count : alloc_count))
 699                        alloc_count = 0;
 700                else if (alloc_count > block_count) {
 701                        alloc_count = block_count;
 702                        eloc.logicalBlockNum += alloc_count;
 703                        elen -= (alloc_count << sb->s_blocksize_bits);
 704                        udf_write_aext(table, &epos, &eloc,
 705                                        (etype << 30) | elen, 1);
 706                } else
 707                        udf_delete_aext(table, epos, eloc,
 708                                        (etype << 30) | elen);
 709        } else {
 710                alloc_count = 0;
 711        }
 712
 713        brelse(epos.bh);
 714
 715        if (alloc_count)
 716                udf_add_free_space(sb, partition, -alloc_count);
 717        mutex_unlock(&sbi->s_alloc_mutex);
 718        return alloc_count;
 719}
 720
 721static int udf_table_new_block(struct super_block *sb,
 722                               struct inode *inode,
 723                               struct inode *table, uint16_t partition,
 724                               uint32_t goal, int *err)
 725{
 726        struct udf_sb_info *sbi = UDF_SB(sb);
 727        uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF;
 728        uint32_t newblock = 0, adsize;
 729        uint32_t elen, goal_elen = 0;
 730        struct kernel_lb_addr eloc, uninitialized_var(goal_eloc);
 731        struct extent_position epos, goal_epos;
 732        int8_t etype;
 733        struct udf_inode_info *iinfo = UDF_I(table);
 734
 735        *err = -ENOSPC;
 736
 737        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
 738                adsize = sizeof(struct short_ad);
 739        else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
 740                adsize = sizeof(struct long_ad);
 741        else
 742                return newblock;
 743
 744        mutex_lock(&sbi->s_alloc_mutex);
 745        if (goal >= sbi->s_partmaps[partition].s_partition_len)
 746                goal = 0;
 747
 748        /* We search for the closest matching block to goal. If we find
 749           a exact hit, we stop. Otherwise we keep going till we run out
 750           of extents. We store the buffer_head, bloc, and extoffset
 751           of the current closest match and use that when we are done.
 752         */
 753        epos.offset = sizeof(struct unallocSpaceEntry);
 754        epos.block = iinfo->i_location;
 755        epos.bh = goal_epos.bh = NULL;
 756
 757        while (spread &&
 758               (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) {
 759                if (goal >= eloc.logicalBlockNum) {
 760                        if (goal < eloc.logicalBlockNum +
 761                                        (elen >> sb->s_blocksize_bits))
 762                                nspread = 0;
 763                        else
 764                                nspread = goal - eloc.logicalBlockNum -
 765                                        (elen >> sb->s_blocksize_bits);
 766                } else {
 767                        nspread = eloc.logicalBlockNum - goal;
 768                }
 769
 770                if (nspread < spread) {
 771                        spread = nspread;
 772                        if (goal_epos.bh != epos.bh) {
 773                                brelse(goal_epos.bh);
 774                                goal_epos.bh = epos.bh;
 775                                get_bh(goal_epos.bh);
 776                        }
 777                        goal_epos.block = epos.block;
 778                        goal_epos.offset = epos.offset - adsize;
 779                        goal_eloc = eloc;
 780                        goal_elen = (etype << 30) | elen;
 781                }
 782        }
 783
 784        brelse(epos.bh);
 785
 786        if (spread == 0xFFFFFFFF) {
 787                brelse(goal_epos.bh);
 788                mutex_unlock(&sbi->s_alloc_mutex);
 789                return 0;
 790        }
 791
 792        /* Only allocate blocks from the beginning of the extent.
 793           That way, we only delete (empty) extents, never have to insert an
 794           extent because of splitting */
 795        /* This works, but very poorly.... */
 796
 797        newblock = goal_eloc.logicalBlockNum;
 798        goal_eloc.logicalBlockNum++;
 799        goal_elen -= sb->s_blocksize;
 800
 801        if (inode && vfs_dq_alloc_block(inode, 1)) {
 802                brelse(goal_epos.bh);
 803                mutex_unlock(&sbi->s_alloc_mutex);
 804                *err = -EDQUOT;
 805                return 0;
 806        }
 807
 808        if (goal_elen)
 809                udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1);
 810        else
 811                udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
 812        brelse(goal_epos.bh);
 813
 814        udf_add_free_space(sb, partition, -1);
 815
 816        mutex_unlock(&sbi->s_alloc_mutex);
 817        *err = 0;
 818        return newblock;
 819}
 820
 821void udf_free_blocks(struct super_block *sb, struct inode *inode,
 822                     struct kernel_lb_addr *bloc, uint32_t offset,
 823                     uint32_t count)
 824{
 825        uint16_t partition = bloc->partitionReferenceNum;
 826        struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 827
 828        if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 829                udf_bitmap_free_blocks(sb, inode, map->s_uspace.s_bitmap,
 830                                       bloc, offset, count);
 831        } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) {
 832                udf_table_free_blocks(sb, inode, map->s_uspace.s_table,
 833                                      bloc, offset, count);
 834        } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) {
 835                udf_bitmap_free_blocks(sb, inode, map->s_fspace.s_bitmap,
 836                                       bloc, offset, count);
 837        } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) {
 838                udf_table_free_blocks(sb, inode, map->s_fspace.s_table,
 839                                      bloc, offset, count);
 840        }
 841}
 842
 843inline int udf_prealloc_blocks(struct super_block *sb,
 844                               struct inode *inode,
 845                               uint16_t partition, uint32_t first_block,
 846                               uint32_t block_count)
 847{
 848        struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 849
 850        if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 851                return udf_bitmap_prealloc_blocks(sb, inode,
 852                                                  map->s_uspace.s_bitmap,
 853                                                  partition, first_block,
 854                                                  block_count);
 855        else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 856                return udf_table_prealloc_blocks(sb, inode,
 857                                                 map->s_uspace.s_table,
 858                                                 partition, first_block,
 859                                                 block_count);
 860        else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 861                return udf_bitmap_prealloc_blocks(sb, inode,
 862                                                  map->s_fspace.s_bitmap,
 863                                                  partition, first_block,
 864                                                  block_count);
 865        else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 866                return udf_table_prealloc_blocks(sb, inode,
 867                                                 map->s_fspace.s_table,
 868                                                 partition, first_block,
 869                                                 block_count);
 870        else
 871                return 0;
 872}
 873
 874inline int udf_new_block(struct super_block *sb,
 875                         struct inode *inode,
 876                         uint16_t partition, uint32_t goal, int *err)
 877{
 878        struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
 879
 880        if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP)
 881                return udf_bitmap_new_block(sb, inode,
 882                                           map->s_uspace.s_bitmap,
 883                                           partition, goal, err);
 884        else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE)
 885                return udf_table_new_block(sb, inode,
 886                                           map->s_uspace.s_table,
 887                                           partition, goal, err);
 888        else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP)
 889                return udf_bitmap_new_block(sb, inode,
 890                                            map->s_fspace.s_bitmap,
 891                                            partition, goal, err);
 892        else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE)
 893                return udf_table_new_block(sb, inode,
 894                                           map->s_fspace.s_table,
 895                                           partition, goal, err);
 896        else {
 897                *err = -EIO;
 898                return 0;
 899        }
 900}
 901