Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/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/buffer_head.h> 25 #include <linux/bitops.h> 26 27 #include "udf_i.h" 28 #include "udf_sb.h" 29 30 #define udf_clear_bit __test_and_clear_bit_le 31 #define udf_set_bit __test_and_set_bit_le 32 #define udf_test_bit test_bit_le 33 #define udf_find_next_one_bit find_next_bit_le 34 35 static int read_block_bitmap(struct super_block *sb, 36 struct udf_bitmap *bitmap, unsigned int block, 37 unsigned long bitmap_nr) 38 { 39 struct buffer_head *bh = NULL; 40 int retval = 0; 41 struct kernel_lb_addr loc; 42 43 loc.logicalBlockNum = bitmap->s_extPosition; 44 loc.partitionReferenceNum = UDF_SB(sb)->s_partition; 45 46 bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block)); 47 if (!bh) 48 retval = -EIO; 49 50 bitmap->s_block_bitmap[bitmap_nr] = bh; 51 return retval; 52 } 53 54 static int __load_block_bitmap(struct super_block *sb, 55 struct udf_bitmap *bitmap, 56 unsigned int block_group) 57 { 58 int retval = 0; 59 int nr_groups = bitmap->s_nr_groups; 60 61 if (block_group >= nr_groups) { 62 udf_debug("block_group (%d) > nr_groups (%d)\n", 63 block_group, nr_groups); 64 } 65 66 if (bitmap->s_block_bitmap[block_group]) { 67 return block_group; 68 } else { 69 retval = read_block_bitmap(sb, bitmap, block_group, 70 block_group); 71 if (retval < 0) 72 return retval; 73 return block_group; 74 } 75 } 76 77 static inline int load_block_bitmap(struct super_block *sb, 78 struct udf_bitmap *bitmap, 79 unsigned int block_group) 80 { 81 int slot; 82 83 slot = __load_block_bitmap(sb, bitmap, block_group); 84 85 if (slot < 0) 86 return slot; 87 88 if (!bitmap->s_block_bitmap[slot]) 89 return -EIO; 90 91 return slot; 92 } 93 94 static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt) 95 { 96 struct udf_sb_info *sbi = UDF_SB(sb); 97 struct logicalVolIntegrityDesc *lvid; 98 99 if (!sbi->s_lvid_bh) 100 return; 101 102 lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data; 103 le32_add_cpu(&lvid->freeSpaceTable[partition], cnt); 104 udf_updated_lvid(sb); 105 } 106 107 static void udf_bitmap_free_blocks(struct super_block *sb, 108 struct udf_bitmap *bitmap, 109 struct kernel_lb_addr *bloc, 110 uint32_t offset, 111 uint32_t count) 112 { 113 struct udf_sb_info *sbi = UDF_SB(sb); 114 struct buffer_head *bh = NULL; 115 struct udf_part_map *partmap; 116 unsigned long block; 117 unsigned long block_group; 118 unsigned long bit; 119 unsigned long i; 120 int bitmap_nr; 121 unsigned long overflow; 122 123 mutex_lock(&sbi->s_alloc_mutex); 124 partmap = &sbi->s_partmaps[bloc->partitionReferenceNum]; 125 if (bloc->logicalBlockNum + count < count || 126 (bloc->logicalBlockNum + count) > partmap->s_partition_len) { 127 udf_debug("%d < %d || %d + %d > %d\n", 128 bloc->logicalBlockNum, 0, 129 bloc->logicalBlockNum, count, 130 partmap->s_partition_len); 131 goto error_return; 132 } 133 134 block = bloc->logicalBlockNum + offset + 135 (sizeof(struct spaceBitmapDesc) << 3); 136 137 do { 138 overflow = 0; 139 block_group = block >> (sb->s_blocksize_bits + 3); 140 bit = block % (sb->s_blocksize << 3); 141 142 /* 143 * Check to see if we are freeing blocks across a group boundary. 144 */ 145 if (bit + count > (sb->s_blocksize << 3)) { 146 overflow = bit + count - (sb->s_blocksize << 3); 147 count -= overflow; 148 } 149 bitmap_nr = load_block_bitmap(sb, bitmap, block_group); 150 if (bitmap_nr < 0) 151 goto error_return; 152 153 bh = bitmap->s_block_bitmap[bitmap_nr]; 154 for (i = 0; i < count; i++) { 155 if (udf_set_bit(bit + i, bh->b_data)) { 156 udf_debug("bit %ld already set\n", bit + i); 157 udf_debug("byte=%2x\n", 158 ((char *)bh->b_data)[(bit + i) >> 3]); 159 } 160 } 161 udf_add_free_space(sb, sbi->s_partition, count); 162 mark_buffer_dirty(bh); 163 if (overflow) { 164 block += count; 165 count = overflow; 166 } 167 } while (overflow); 168 169 error_return: 170 mutex_unlock(&sbi->s_alloc_mutex); 171 } 172 173 static int udf_bitmap_prealloc_blocks(struct super_block *sb, 174 struct udf_bitmap *bitmap, 175 uint16_t partition, uint32_t first_block, 176 uint32_t block_count) 177 { 178 struct udf_sb_info *sbi = UDF_SB(sb); 179 int alloc_count = 0; 180 int bit, block, block_group, group_start; 181 int nr_groups, bitmap_nr; 182 struct buffer_head *bh; 183 __u32 part_len; 184 185 mutex_lock(&sbi->s_alloc_mutex); 186 part_len = sbi->s_partmaps[partition].s_partition_len; 187 if (first_block >= part_len) 188 goto out; 189 190 if (first_block + block_count > part_len) 191 block_count = part_len - first_block; 192 193 do { 194 nr_groups = udf_compute_nr_groups(sb, partition); 195 block = first_block + (sizeof(struct spaceBitmapDesc) << 3); 196 block_group = block >> (sb->s_blocksize_bits + 3); 197 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc); 198 199 bitmap_nr = load_block_bitmap(sb, bitmap, block_group); 200 if (bitmap_nr < 0) 201 goto out; 202 bh = bitmap->s_block_bitmap[bitmap_nr]; 203 204 bit = block % (sb->s_blocksize << 3); 205 206 while (bit < (sb->s_blocksize << 3) && block_count > 0) { 207 if (!udf_clear_bit(bit, bh->b_data)) 208 goto out; 209 block_count--; 210 alloc_count++; 211 bit++; 212 block++; 213 } 214 mark_buffer_dirty(bh); 215 } while (block_count > 0); 216 217 out: 218 udf_add_free_space(sb, partition, -alloc_count); 219 mutex_unlock(&sbi->s_alloc_mutex); 220 return alloc_count; 221 } 222 223 static int udf_bitmap_new_block(struct super_block *sb, 224 struct udf_bitmap *bitmap, uint16_t partition, 225 uint32_t goal, int *err) 226 { 227 struct udf_sb_info *sbi = UDF_SB(sb); 228 int newbit, bit = 0, block, block_group, group_start; 229 int end_goal, nr_groups, bitmap_nr, i; 230 struct buffer_head *bh = NULL; 231 char *ptr; 232 int newblock = 0; 233 234 *err = -ENOSPC; 235 mutex_lock(&sbi->s_alloc_mutex); 236 237 repeat: 238 if (goal >= sbi->s_partmaps[partition].s_partition_len) 239 goal = 0; 240 241 nr_groups = bitmap->s_nr_groups; 242 block = goal + (sizeof(struct spaceBitmapDesc) << 3); 243 block_group = block >> (sb->s_blocksize_bits + 3); 244 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc); 245 246 bitmap_nr = load_block_bitmap(sb, bitmap, block_group); 247 if (bitmap_nr < 0) 248 goto error_return; 249 bh = bitmap->s_block_bitmap[bitmap_nr]; 250 ptr = memscan((char *)bh->b_data + group_start, 0xFF, 251 sb->s_blocksize - group_start); 252 253 if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) { 254 bit = block % (sb->s_blocksize << 3); 255 if (udf_test_bit(bit, bh->b_data)) 256 goto got_block; 257 258 end_goal = (bit + 63) & ~63; 259 bit = udf_find_next_one_bit(bh->b_data, end_goal, bit); 260 if (bit < end_goal) 261 goto got_block; 262 263 ptr = memscan((char *)bh->b_data + (bit >> 3), 0xFF, 264 sb->s_blocksize - ((bit + 7) >> 3)); 265 newbit = (ptr - ((char *)bh->b_data)) << 3; 266 if (newbit < sb->s_blocksize << 3) { 267 bit = newbit; 268 goto search_back; 269 } 270 271 newbit = udf_find_next_one_bit(bh->b_data, 272 sb->s_blocksize << 3, bit); 273 if (newbit < sb->s_blocksize << 3) { 274 bit = newbit; 275 goto got_block; 276 } 277 } 278 279 for (i = 0; i < (nr_groups * 2); i++) { 280 block_group++; 281 if (block_group >= nr_groups) 282 block_group = 0; 283 group_start = block_group ? 0 : sizeof(struct spaceBitmapDesc); 284 285 bitmap_nr = load_block_bitmap(sb, bitmap, block_group); 286 if (bitmap_nr < 0) 287 goto error_return; 288 bh = bitmap->s_block_bitmap[bitmap_nr]; 289 if (i < nr_groups) { 290 ptr = memscan((char *)bh->b_data + group_start, 0xFF, 291 sb->s_blocksize - group_start); 292 if ((ptr - ((char *)bh->b_data)) < sb->s_blocksize) { 293 bit = (ptr - ((char *)bh->b_data)) << 3; 294 break; 295 } 296 } else { 297 bit = udf_find_next_one_bit(bh->b_data, 298 sb->s_blocksize << 3, 299 group_start << 3); 300 if (bit < sb->s_blocksize << 3) 301 break; 302 } 303 } 304 if (i >= (nr_groups * 2)) { 305 mutex_unlock(&sbi->s_alloc_mutex); 306 return newblock; 307 } 308 if (bit < sb->s_blocksize << 3) 309 goto search_back; 310 else 311 bit = udf_find_next_one_bit(bh->b_data, sb->s_blocksize << 3, 312 group_start << 3); 313 if (bit >= sb->s_blocksize << 3) { 314 mutex_unlock(&sbi->s_alloc_mutex); 315 return 0; 316 } 317 318 search_back: 319 i = 0; 320 while (i < 7 && bit > (group_start << 3) && 321 udf_test_bit(bit - 1, bh->b_data)) { 322 ++i; 323 --bit; 324 } 325 326 got_block: 327 newblock = bit + (block_group << (sb->s_blocksize_bits + 3)) - 328 (sizeof(struct spaceBitmapDesc) << 3); 329 330 if (!udf_clear_bit(bit, bh->b_data)) { 331 udf_debug("bit already cleared for block %d\n", bit); 332 goto repeat; 333 } 334 335 mark_buffer_dirty(bh); 336 337 udf_add_free_space(sb, partition, -1); 338 mutex_unlock(&sbi->s_alloc_mutex); 339 *err = 0; 340 return newblock; 341 342 error_return: 343 *err = -EIO; 344 mutex_unlock(&sbi->s_alloc_mutex); 345 return 0; 346 } 347 348 static void udf_table_free_blocks(struct super_block *sb, 349 struct inode *table, 350 struct kernel_lb_addr *bloc, 351 uint32_t offset, 352 uint32_t count) 353 { 354 struct udf_sb_info *sbi = UDF_SB(sb); 355 struct udf_part_map *partmap; 356 uint32_t start, end; 357 uint32_t elen; 358 struct kernel_lb_addr eloc; 359 struct extent_position oepos, epos; 360 int8_t etype; 361 int i; 362 struct udf_inode_info *iinfo; 363 364 mutex_lock(&sbi->s_alloc_mutex); 365 partmap = &sbi->s_partmaps[bloc->partitionReferenceNum]; 366 if (bloc->logicalBlockNum + count < count || 367 (bloc->logicalBlockNum + count) > partmap->s_partition_len) { 368 udf_debug("%d < %d || %d + %d > %d\n", 369 bloc->logicalBlockNum, 0, 370 bloc->logicalBlockNum, count, 371 partmap->s_partition_len); 372 goto error_return; 373 } 374 375 iinfo = UDF_I(table); 376 udf_add_free_space(sb, sbi->s_partition, count); 377 378 start = bloc->logicalBlockNum + offset; 379 end = bloc->logicalBlockNum + offset + count - 1; 380 381 epos.offset = oepos.offset = sizeof(struct unallocSpaceEntry); 382 elen = 0; 383 epos.block = oepos.block = iinfo->i_location; 384 epos.bh = oepos.bh = NULL; 385 386 while (count && 387 (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) { 388 if (((eloc.logicalBlockNum + 389 (elen >> sb->s_blocksize_bits)) == start)) { 390 if ((0x3FFFFFFF - elen) < 391 (count << sb->s_blocksize_bits)) { 392 uint32_t tmp = ((0x3FFFFFFF - elen) >> 393 sb->s_blocksize_bits); 394 count -= tmp; 395 start += tmp; 396 elen = (etype << 30) | 397 (0x40000000 - sb->s_blocksize); 398 } else { 399 elen = (etype << 30) | 400 (elen + 401 (count << sb->s_blocksize_bits)); 402 start += count; 403 count = 0; 404 } 405 udf_write_aext(table, &oepos, &eloc, elen, 1); 406 } else if (eloc.logicalBlockNum == (end + 1)) { 407 if ((0x3FFFFFFF - elen) < 408 (count << sb->s_blocksize_bits)) { 409 uint32_t tmp = ((0x3FFFFFFF - elen) >> 410 sb->s_blocksize_bits); 411 count -= tmp; 412 end -= tmp; 413 eloc.logicalBlockNum -= tmp; 414 elen = (etype << 30) | 415 (0x40000000 - sb->s_blocksize); 416 } else { 417 eloc.logicalBlockNum = start; 418 elen = (etype << 30) | 419 (elen + 420 (count << sb->s_blocksize_bits)); 421 end -= count; 422 count = 0; 423 } 424 udf_write_aext(table, &oepos, &eloc, elen, 1); 425 } 426 427 if (epos.bh != oepos.bh) { 428 i = -1; 429 oepos.block = epos.block; 430 brelse(oepos.bh); 431 get_bh(epos.bh); 432 oepos.bh = epos.bh; 433 oepos.offset = 0; 434 } else { 435 oepos.offset = epos.offset; 436 } 437 } 438 439 if (count) { 440 /* 441 * NOTE: we CANNOT use udf_add_aext here, as it can try to 442 * allocate a new block, and since we hold the super block 443 * lock already very bad things would happen :) 444 * 445 * We copy the behavior of udf_add_aext, but instead of 446 * trying to allocate a new block close to the existing one, 447 * we just steal a block from the extent we are trying to add. 448 * 449 * It would be nice if the blocks were close together, but it 450 * isn't required. 451 */ 452 453 int adsize; 454 struct short_ad *sad = NULL; 455 struct long_ad *lad = NULL; 456 struct allocExtDesc *aed; 457 458 eloc.logicalBlockNum = start; 459 elen = EXT_RECORDED_ALLOCATED | 460 (count << sb->s_blocksize_bits); 461 462 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) 463 adsize = sizeof(struct short_ad); 464 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG) 465 adsize = sizeof(struct long_ad); 466 else { 467 brelse(oepos.bh); 468 brelse(epos.bh); 469 goto error_return; 470 } 471 472 if (epos.offset + (2 * adsize) > sb->s_blocksize) { 473 unsigned char *sptr, *dptr; 474 int loffset; 475 476 brelse(oepos.bh); 477 oepos = epos; 478 479 /* Steal a block from the extent being free'd */ 480 epos.block.logicalBlockNum = eloc.logicalBlockNum; 481 eloc.logicalBlockNum++; 482 elen -= sb->s_blocksize; 483 484 epos.bh = udf_tread(sb, 485 udf_get_lb_pblock(sb, &epos.block, 0)); 486 if (!epos.bh) { 487 brelse(oepos.bh); 488 goto error_return; 489 } 490 aed = (struct allocExtDesc *)(epos.bh->b_data); 491 aed->previousAllocExtLocation = 492 cpu_to_le32(oepos.block.logicalBlockNum); 493 if (epos.offset + adsize > sb->s_blocksize) { 494 loffset = epos.offset; 495 aed->lengthAllocDescs = cpu_to_le32(adsize); 496 sptr = iinfo->i_ext.i_data + epos.offset 497 - adsize; 498 dptr = epos.bh->b_data + 499 sizeof(struct allocExtDesc); 500 memcpy(dptr, sptr, adsize); 501 epos.offset = sizeof(struct allocExtDesc) + 502 adsize; 503 } else { 504 loffset = epos.offset + adsize; 505 aed->lengthAllocDescs = cpu_to_le32(0); 506 if (oepos.bh) { 507 sptr = oepos.bh->b_data + epos.offset; 508 aed = (struct allocExtDesc *) 509 oepos.bh->b_data; 510 le32_add_cpu(&aed->lengthAllocDescs, 511 adsize); 512 } else { 513 sptr = iinfo->i_ext.i_data + 514 epos.offset; 515 iinfo->i_lenAlloc += adsize; 516 mark_inode_dirty(table); 517 } 518 epos.offset = sizeof(struct allocExtDesc); 519 } 520 if (sbi->s_udfrev >= 0x0200) 521 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 522 3, 1, epos.block.logicalBlockNum, 523 sizeof(struct tag)); 524 else 525 udf_new_tag(epos.bh->b_data, TAG_IDENT_AED, 526 2, 1, epos.block.logicalBlockNum, 527 sizeof(struct tag)); 528 529 switch (iinfo->i_alloc_type) { 530 case ICBTAG_FLAG_AD_SHORT: 531 sad = (struct short_ad *)sptr; 532 sad->extLength = cpu_to_le32( 533 EXT_NEXT_EXTENT_ALLOCDECS | 534 sb->s_blocksize); 535 sad->extPosition = 536 cpu_to_le32(epos.block.logicalBlockNum); 537 break; 538 case ICBTAG_FLAG_AD_LONG: 539 lad = (struct long_ad *)sptr; 540 lad->extLength = cpu_to_le32( 541 EXT_NEXT_EXTENT_ALLOCDECS | 542 sb->s_blocksize); 543 lad->extLocation = 544 cpu_to_lelb(epos.block); 545 break; 546 } 547 if (oepos.bh) { 548 udf_update_tag(oepos.bh->b_data, loffset); 549 mark_buffer_dirty(oepos.bh); 550 } else { 551 mark_inode_dirty(table); 552 } 553 } 554 555 /* It's possible that stealing the block emptied the extent */ 556 if (elen) { 557 udf_write_aext(table, &epos, &eloc, elen, 1); 558 559 if (!epos.bh) { 560 iinfo->i_lenAlloc += adsize; 561 mark_inode_dirty(table); 562 } else { 563 aed = (struct allocExtDesc *)epos.bh->b_data; 564 le32_add_cpu(&aed->lengthAllocDescs, adsize); 565 udf_update_tag(epos.bh->b_data, epos.offset); 566 mark_buffer_dirty(epos.bh); 567 } 568 } 569 } 570 571 brelse(epos.bh); 572 brelse(oepos.bh); 573 574 error_return: 575 mutex_unlock(&sbi->s_alloc_mutex); 576 return; 577 } 578 579 static int udf_table_prealloc_blocks(struct super_block *sb, 580 struct inode *table, uint16_t partition, 581 uint32_t first_block, uint32_t block_count) 582 { 583 struct udf_sb_info *sbi = UDF_SB(sb); 584 int alloc_count = 0; 585 uint32_t elen, adsize; 586 struct kernel_lb_addr eloc; 587 struct extent_position epos; 588 int8_t etype = -1; 589 struct udf_inode_info *iinfo; 590 591 if (first_block >= sbi->s_partmaps[partition].s_partition_len) 592 return 0; 593 594 iinfo = UDF_I(table); 595 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) 596 adsize = sizeof(struct short_ad); 597 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG) 598 adsize = sizeof(struct long_ad); 599 else 600 return 0; 601 602 mutex_lock(&sbi->s_alloc_mutex); 603 epos.offset = sizeof(struct unallocSpaceEntry); 604 epos.block = iinfo->i_location; 605 epos.bh = NULL; 606 eloc.logicalBlockNum = 0xFFFFFFFF; 607 608 while (first_block != eloc.logicalBlockNum && 609 (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) { 610 udf_debug("eloc=%d, elen=%d, first_block=%d\n", 611 eloc.logicalBlockNum, elen, first_block); 612 ; /* empty loop body */ 613 } 614 615 if (first_block == eloc.logicalBlockNum) { 616 epos.offset -= adsize; 617 618 alloc_count = (elen >> sb->s_blocksize_bits); 619 if (alloc_count > block_count) { 620 alloc_count = block_count; 621 eloc.logicalBlockNum += alloc_count; 622 elen -= (alloc_count << sb->s_blocksize_bits); 623 udf_write_aext(table, &epos, &eloc, 624 (etype << 30) | elen, 1); 625 } else 626 udf_delete_aext(table, epos, eloc, 627 (etype << 30) | elen); 628 } else { 629 alloc_count = 0; 630 } 631 632 brelse(epos.bh); 633 634 if (alloc_count) 635 udf_add_free_space(sb, partition, -alloc_count); 636 mutex_unlock(&sbi->s_alloc_mutex); 637 return alloc_count; 638 } 639 640 static int udf_table_new_block(struct super_block *sb, 641 struct inode *table, uint16_t partition, 642 uint32_t goal, int *err) 643 { 644 struct udf_sb_info *sbi = UDF_SB(sb); 645 uint32_t spread = 0xFFFFFFFF, nspread = 0xFFFFFFFF; 646 uint32_t newblock = 0, adsize; 647 uint32_t elen, goal_elen = 0; 648 struct kernel_lb_addr eloc, uninitialized_var(goal_eloc); 649 struct extent_position epos, goal_epos; 650 int8_t etype; 651 struct udf_inode_info *iinfo = UDF_I(table); 652 653 *err = -ENOSPC; 654 655 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT) 656 adsize = sizeof(struct short_ad); 657 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG) 658 adsize = sizeof(struct long_ad); 659 else 660 return newblock; 661 662 mutex_lock(&sbi->s_alloc_mutex); 663 if (goal >= sbi->s_partmaps[partition].s_partition_len) 664 goal = 0; 665 666 /* We search for the closest matching block to goal. If we find 667 a exact hit, we stop. Otherwise we keep going till we run out 668 of extents. We store the buffer_head, bloc, and extoffset 669 of the current closest match and use that when we are done. 670 */ 671 epos.offset = sizeof(struct unallocSpaceEntry); 672 epos.block = iinfo->i_location; 673 epos.bh = goal_epos.bh = NULL; 674 675 while (spread && 676 (etype = udf_next_aext(table, &epos, &eloc, &elen, 1)) != -1) { 677 if (goal >= eloc.logicalBlockNum) { 678 if (goal < eloc.logicalBlockNum + 679 (elen >> sb->s_blocksize_bits)) 680 nspread = 0; 681 else 682 nspread = goal - eloc.logicalBlockNum - 683 (elen >> sb->s_blocksize_bits); 684 } else { 685 nspread = eloc.logicalBlockNum - goal; 686 } 687 688 if (nspread < spread) { 689 spread = nspread; 690 if (goal_epos.bh != epos.bh) { 691 brelse(goal_epos.bh); 692 goal_epos.bh = epos.bh; 693 get_bh(goal_epos.bh); 694 } 695 goal_epos.block = epos.block; 696 goal_epos.offset = epos.offset - adsize; 697 goal_eloc = eloc; 698 goal_elen = (etype << 30) | elen; 699 } 700 } 701 702 brelse(epos.bh); 703 704 if (spread == 0xFFFFFFFF) { 705 brelse(goal_epos.bh); 706 mutex_unlock(&sbi->s_alloc_mutex); 707 return 0; 708 } 709 710 /* Only allocate blocks from the beginning of the extent. 711 That way, we only delete (empty) extents, never have to insert an 712 extent because of splitting */ 713 /* This works, but very poorly.... */ 714 715 newblock = goal_eloc.logicalBlockNum; 716 goal_eloc.logicalBlockNum++; 717 goal_elen -= sb->s_blocksize; 718 719 if (goal_elen) 720 udf_write_aext(table, &goal_epos, &goal_eloc, goal_elen, 1); 721 else 722 udf_delete_aext(table, goal_epos, goal_eloc, goal_elen); 723 brelse(goal_epos.bh); 724 725 udf_add_free_space(sb, partition, -1); 726 727 mutex_unlock(&sbi->s_alloc_mutex); 728 *err = 0; 729 return newblock; 730 } 731 732 void udf_free_blocks(struct super_block *sb, struct inode *inode, 733 struct kernel_lb_addr *bloc, uint32_t offset, 734 uint32_t count) 735 { 736 uint16_t partition = bloc->partitionReferenceNum; 737 struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition]; 738 739 if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) { 740 udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap, 741 bloc, offset, count); 742 } else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) { 743 udf_table_free_blocks(sb, map->s_uspace.s_table, 744 bloc, offset, count); 745 } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) { 746 udf_bitmap_free_blocks(sb, map->s_fspace.s_bitmap, 747 bloc, offset, count); 748 } else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) { 749 udf_table_free_blocks(sb, map->s_fspace.s_table, 750 bloc, offset, count); 751 } 752 753 if (inode) { 754 inode_sub_bytes(inode, 755 ((sector_t)count) << sb->s_blocksize_bits); 756 } 757 } 758 759 inline int udf_prealloc_blocks(struct super_block *sb, 760 struct inode *inode, 761 uint16_t partition, uint32_t first_block, 762 uint32_t block_count) 763 { 764 struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition]; 765 sector_t allocated; 766 767 if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) 768 allocated = udf_bitmap_prealloc_blocks(sb, 769 map->s_uspace.s_bitmap, 770 partition, first_block, 771 block_count); 772 else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) 773 allocated = udf_table_prealloc_blocks(sb, 774 map->s_uspace.s_table, 775 partition, first_block, 776 block_count); 777 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) 778 allocated = udf_bitmap_prealloc_blocks(sb, 779 map->s_fspace.s_bitmap, 780 partition, first_block, 781 block_count); 782 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) 783 allocated = udf_table_prealloc_blocks(sb, 784 map->s_fspace.s_table, 785 partition, first_block, 786 block_count); 787 else 788 return 0; 789 790 if (inode && allocated > 0) 791 inode_add_bytes(inode, allocated << sb->s_blocksize_bits); 792 return allocated; 793 } 794 795 inline int udf_new_block(struct super_block *sb, 796 struct inode *inode, 797 uint16_t partition, uint32_t goal, int *err) 798 { 799 struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition]; 800 int block; 801 802 if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) 803 block = udf_bitmap_new_block(sb, 804 map->s_uspace.s_bitmap, 805 partition, goal, err); 806 else if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_TABLE) 807 block = udf_table_new_block(sb, 808 map->s_uspace.s_table, 809 partition, goal, err); 810 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_BITMAP) 811 block = udf_bitmap_new_block(sb, 812 map->s_fspace.s_bitmap, 813 partition, goal, err); 814 else if (map->s_partition_flags & UDF_PART_FLAG_FREED_TABLE) 815 block = udf_table_new_block(sb, 816 map->s_fspace.s_table, 817 partition, goal, err); 818 else { 819 *err = -EIO; 820 return 0; 821 } 822 if (inode && block) 823 inode_add_bytes(inode, sb->s_blocksize); 824 return block; 825 }
Cache object: 4fb9067fe5f80f253910b9c00161b4b9
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