1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/hfsplus/extents.c 4 * 5 * Copyright (C) 2001 6 * Brad Boyer (flar@allandria.com) 7 * (C) 2003 Ardis Technologies <roman@ardistech.com> 8 * 9 * Handling of Extents both in catalog and extents overflow trees 10 */ 11 12 #include <linux/errno.h> 13 #include <linux/fs.h> 14 #include <linux/pagemap.h> 15 16 #include "hfsplus_fs.h" 17 #include "hfsplus_raw.h" 18 19 /* Compare two extents keys, returns 0 on same, pos/neg for difference */ 20 int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1, 21 const hfsplus_btree_key *k2) 22 { 23 __be32 k1id, k2id; 24 __be32 k1s, k2s; 25 26 k1id = k1->ext.cnid; 27 k2id = k2->ext.cnid; 28 if (k1id != k2id) 29 return be32_to_cpu(k1id) < be32_to_cpu(k2id) ? -1 : 1; 30 31 if (k1->ext.fork_type != k2->ext.fork_type) 32 return k1->ext.fork_type < k2->ext.fork_type ? -1 : 1; 33 34 k1s = k1->ext.start_block; 35 k2s = k2->ext.start_block; 36 if (k1s == k2s) 37 return 0; 38 return be32_to_cpu(k1s) < be32_to_cpu(k2s) ? -1 : 1; 39 } 40 41 static void hfsplus_ext_build_key(hfsplus_btree_key *key, u32 cnid, 42 u32 block, u8 type) 43 { 44 key->key_len = cpu_to_be16(HFSPLUS_EXT_KEYLEN - 2); 45 key->ext.cnid = cpu_to_be32(cnid); 46 key->ext.start_block = cpu_to_be32(block); 47 key->ext.fork_type = type; 48 key->ext.pad = 0; 49 } 50 51 static u32 hfsplus_ext_find_block(struct hfsplus_extent *ext, u32 off) 52 { 53 int i; 54 u32 count; 55 56 for (i = 0; i < 8; ext++, i++) { 57 count = be32_to_cpu(ext->block_count); 58 if (off < count) 59 return be32_to_cpu(ext->start_block) + off; 60 off -= count; 61 } 62 /* panic? */ 63 return 0; 64 } 65 66 static int hfsplus_ext_block_count(struct hfsplus_extent *ext) 67 { 68 int i; 69 u32 count = 0; 70 71 for (i = 0; i < 8; ext++, i++) 72 count += be32_to_cpu(ext->block_count); 73 return count; 74 } 75 76 static u32 hfsplus_ext_lastblock(struct hfsplus_extent *ext) 77 { 78 int i; 79 80 ext += 7; 81 for (i = 0; i < 7; ext--, i++) 82 if (ext->block_count) 83 break; 84 return be32_to_cpu(ext->start_block) + be32_to_cpu(ext->block_count); 85 } 86 87 static int __hfsplus_ext_write_extent(struct inode *inode, 88 struct hfs_find_data *fd) 89 { 90 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 91 int res; 92 93 WARN_ON(!mutex_is_locked(&hip->extents_lock)); 94 95 hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start, 96 HFSPLUS_IS_RSRC(inode) ? 97 HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA); 98 99 res = hfs_brec_find(fd, hfs_find_rec_by_key); 100 if (hip->extent_state & HFSPLUS_EXT_NEW) { 101 if (res != -ENOENT) 102 return res; 103 hfs_brec_insert(fd, hip->cached_extents, 104 sizeof(hfsplus_extent_rec)); 105 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW); 106 } else { 107 if (res) 108 return res; 109 hfs_bnode_write(fd->bnode, hip->cached_extents, 110 fd->entryoffset, fd->entrylength); 111 hip->extent_state &= ~HFSPLUS_EXT_DIRTY; 112 } 113 114 /* 115 * We can't just use hfsplus_mark_inode_dirty here, because we 116 * also get called from hfsplus_write_inode, which should not 117 * redirty the inode. Instead the callers have to be careful 118 * to explicily mark the inode dirty, too. 119 */ 120 set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags); 121 122 return 0; 123 } 124 125 static int hfsplus_ext_write_extent_locked(struct inode *inode) 126 { 127 int res = 0; 128 129 if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) { 130 struct hfs_find_data fd; 131 132 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd); 133 if (res) 134 return res; 135 res = __hfsplus_ext_write_extent(inode, &fd); 136 hfs_find_exit(&fd); 137 } 138 return res; 139 } 140 141 int hfsplus_ext_write_extent(struct inode *inode) 142 { 143 int res; 144 145 mutex_lock(&HFSPLUS_I(inode)->extents_lock); 146 res = hfsplus_ext_write_extent_locked(inode); 147 mutex_unlock(&HFSPLUS_I(inode)->extents_lock); 148 149 return res; 150 } 151 152 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd, 153 struct hfsplus_extent *extent, 154 u32 cnid, u32 block, u8 type) 155 { 156 int res; 157 158 hfsplus_ext_build_key(fd->search_key, cnid, block, type); 159 fd->key->ext.cnid = 0; 160 res = hfs_brec_find(fd, hfs_find_rec_by_key); 161 if (res && res != -ENOENT) 162 return res; 163 if (fd->key->ext.cnid != fd->search_key->ext.cnid || 164 fd->key->ext.fork_type != fd->search_key->ext.fork_type) 165 return -ENOENT; 166 if (fd->entrylength != sizeof(hfsplus_extent_rec)) 167 return -EIO; 168 hfs_bnode_read(fd->bnode, extent, fd->entryoffset, 169 sizeof(hfsplus_extent_rec)); 170 return 0; 171 } 172 173 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, 174 struct inode *inode, u32 block) 175 { 176 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 177 int res; 178 179 WARN_ON(!mutex_is_locked(&hip->extents_lock)); 180 181 if (hip->extent_state & HFSPLUS_EXT_DIRTY) { 182 res = __hfsplus_ext_write_extent(inode, fd); 183 if (res) 184 return res; 185 } 186 187 res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino, 188 block, HFSPLUS_IS_RSRC(inode) ? 189 HFSPLUS_TYPE_RSRC : 190 HFSPLUS_TYPE_DATA); 191 if (!res) { 192 hip->cached_start = be32_to_cpu(fd->key->ext.start_block); 193 hip->cached_blocks = 194 hfsplus_ext_block_count(hip->cached_extents); 195 } else { 196 hip->cached_start = hip->cached_blocks = 0; 197 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW); 198 } 199 return res; 200 } 201 202 static int hfsplus_ext_read_extent(struct inode *inode, u32 block) 203 { 204 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 205 struct hfs_find_data fd; 206 int res; 207 208 if (block >= hip->cached_start && 209 block < hip->cached_start + hip->cached_blocks) 210 return 0; 211 212 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd); 213 if (!res) { 214 res = __hfsplus_ext_cache_extent(&fd, inode, block); 215 hfs_find_exit(&fd); 216 } 217 return res; 218 } 219 220 /* Get a block at iblock for inode, possibly allocating if create */ 221 int hfsplus_get_block(struct inode *inode, sector_t iblock, 222 struct buffer_head *bh_result, int create) 223 { 224 struct super_block *sb = inode->i_sb; 225 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); 226 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 227 int res = -EIO; 228 u32 ablock, dblock, mask; 229 sector_t sector; 230 int was_dirty = 0; 231 232 /* Convert inode block to disk allocation block */ 233 ablock = iblock >> sbi->fs_shift; 234 235 if (iblock >= hip->fs_blocks) { 236 if (iblock > hip->fs_blocks || !create) 237 return -EIO; 238 if (ablock >= hip->alloc_blocks) { 239 res = hfsplus_file_extend(inode, false); 240 if (res) 241 return res; 242 } 243 } else 244 create = 0; 245 246 if (ablock < hip->first_blocks) { 247 dblock = hfsplus_ext_find_block(hip->first_extents, ablock); 248 goto done; 249 } 250 251 if (inode->i_ino == HFSPLUS_EXT_CNID) 252 return -EIO; 253 254 mutex_lock(&hip->extents_lock); 255 256 /* 257 * hfsplus_ext_read_extent will write out a cached extent into 258 * the extents btree. In that case we may have to mark the inode 259 * dirty even for a pure read of an extent here. 260 */ 261 was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY); 262 res = hfsplus_ext_read_extent(inode, ablock); 263 if (res) { 264 mutex_unlock(&hip->extents_lock); 265 return -EIO; 266 } 267 dblock = hfsplus_ext_find_block(hip->cached_extents, 268 ablock - hip->cached_start); 269 mutex_unlock(&hip->extents_lock); 270 271 done: 272 hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n", 273 inode->i_ino, (long long)iblock, dblock); 274 275 mask = (1 << sbi->fs_shift) - 1; 276 sector = ((sector_t)dblock << sbi->fs_shift) + 277 sbi->blockoffset + (iblock & mask); 278 map_bh(bh_result, sb, sector); 279 280 if (create) { 281 set_buffer_new(bh_result); 282 hip->phys_size += sb->s_blocksize; 283 hip->fs_blocks++; 284 inode_add_bytes(inode, sb->s_blocksize); 285 } 286 if (create || was_dirty) 287 mark_inode_dirty(inode); 288 return 0; 289 } 290 291 static void hfsplus_dump_extent(struct hfsplus_extent *extent) 292 { 293 int i; 294 295 hfs_dbg(EXTENT, " "); 296 for (i = 0; i < 8; i++) 297 hfs_dbg_cont(EXTENT, " %u:%u", 298 be32_to_cpu(extent[i].start_block), 299 be32_to_cpu(extent[i].block_count)); 300 hfs_dbg_cont(EXTENT, "\n"); 301 } 302 303 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset, 304 u32 alloc_block, u32 block_count) 305 { 306 u32 count, start; 307 int i; 308 309 hfsplus_dump_extent(extent); 310 for (i = 0; i < 8; extent++, i++) { 311 count = be32_to_cpu(extent->block_count); 312 if (offset == count) { 313 start = be32_to_cpu(extent->start_block); 314 if (alloc_block != start + count) { 315 if (++i >= 8) 316 return -ENOSPC; 317 extent++; 318 extent->start_block = cpu_to_be32(alloc_block); 319 } else 320 block_count += count; 321 extent->block_count = cpu_to_be32(block_count); 322 return 0; 323 } else if (offset < count) 324 break; 325 offset -= count; 326 } 327 /* panic? */ 328 return -EIO; 329 } 330 331 static int hfsplus_free_extents(struct super_block *sb, 332 struct hfsplus_extent *extent, 333 u32 offset, u32 block_nr) 334 { 335 u32 count, start; 336 int i; 337 int err = 0; 338 339 /* Mapping the allocation file may lock the extent tree */ 340 WARN_ON(mutex_is_locked(&HFSPLUS_SB(sb)->ext_tree->tree_lock)); 341 342 hfsplus_dump_extent(extent); 343 for (i = 0; i < 8; extent++, i++) { 344 count = be32_to_cpu(extent->block_count); 345 if (offset == count) 346 goto found; 347 else if (offset < count) 348 break; 349 offset -= count; 350 } 351 /* panic? */ 352 return -EIO; 353 found: 354 for (;;) { 355 start = be32_to_cpu(extent->start_block); 356 if (count <= block_nr) { 357 err = hfsplus_block_free(sb, start, count); 358 if (err) { 359 pr_err("can't free extent\n"); 360 hfs_dbg(EXTENT, " start: %u count: %u\n", 361 start, count); 362 } 363 extent->block_count = 0; 364 extent->start_block = 0; 365 block_nr -= count; 366 } else { 367 count -= block_nr; 368 err = hfsplus_block_free(sb, start + count, block_nr); 369 if (err) { 370 pr_err("can't free extent\n"); 371 hfs_dbg(EXTENT, " start: %u count: %u\n", 372 start, count); 373 } 374 extent->block_count = cpu_to_be32(count); 375 block_nr = 0; 376 } 377 if (!block_nr || !i) { 378 /* 379 * Try to free all extents and 380 * return only last error 381 */ 382 return err; 383 } 384 i--; 385 extent--; 386 count = be32_to_cpu(extent->block_count); 387 } 388 } 389 390 int hfsplus_free_fork(struct super_block *sb, u32 cnid, 391 struct hfsplus_fork_raw *fork, int type) 392 { 393 struct hfs_find_data fd; 394 hfsplus_extent_rec ext_entry; 395 u32 total_blocks, blocks, start; 396 int res, i; 397 398 total_blocks = be32_to_cpu(fork->total_blocks); 399 if (!total_blocks) 400 return 0; 401 402 blocks = 0; 403 for (i = 0; i < 8; i++) 404 blocks += be32_to_cpu(fork->extents[i].block_count); 405 406 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks); 407 if (res) 408 return res; 409 if (total_blocks == blocks) 410 return 0; 411 412 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd); 413 if (res) 414 return res; 415 do { 416 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid, 417 total_blocks, type); 418 if (res) 419 break; 420 start = be32_to_cpu(fd.key->ext.start_block); 421 hfs_brec_remove(&fd); 422 423 mutex_unlock(&fd.tree->tree_lock); 424 hfsplus_free_extents(sb, ext_entry, total_blocks - start, 425 total_blocks); 426 total_blocks = start; 427 mutex_lock(&fd.tree->tree_lock); 428 } while (total_blocks > blocks); 429 hfs_find_exit(&fd); 430 431 return res; 432 } 433 434 int hfsplus_file_extend(struct inode *inode, bool zeroout) 435 { 436 struct super_block *sb = inode->i_sb; 437 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); 438 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 439 u32 start, len, goal; 440 int res; 441 442 if (sbi->alloc_file->i_size * 8 < 443 sbi->total_blocks - sbi->free_blocks + 8) { 444 /* extend alloc file */ 445 pr_err("extend alloc file! (%llu,%u,%u)\n", 446 sbi->alloc_file->i_size * 8, 447 sbi->total_blocks, sbi->free_blocks); 448 return -ENOSPC; 449 } 450 451 mutex_lock(&hip->extents_lock); 452 if (hip->alloc_blocks == hip->first_blocks) 453 goal = hfsplus_ext_lastblock(hip->first_extents); 454 else { 455 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks); 456 if (res) 457 goto out; 458 goal = hfsplus_ext_lastblock(hip->cached_extents); 459 } 460 461 len = hip->clump_blocks; 462 start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len); 463 if (start >= sbi->total_blocks) { 464 start = hfsplus_block_allocate(sb, goal, 0, &len); 465 if (start >= goal) { 466 res = -ENOSPC; 467 goto out; 468 } 469 } 470 471 if (zeroout) { 472 res = sb_issue_zeroout(sb, start, len, GFP_NOFS); 473 if (res) 474 goto out; 475 } 476 477 hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len); 478 479 if (hip->alloc_blocks <= hip->first_blocks) { 480 if (!hip->first_blocks) { 481 hfs_dbg(EXTENT, "first extents\n"); 482 /* no extents yet */ 483 hip->first_extents[0].start_block = cpu_to_be32(start); 484 hip->first_extents[0].block_count = cpu_to_be32(len); 485 res = 0; 486 } else { 487 /* try to append to extents in inode */ 488 res = hfsplus_add_extent(hip->first_extents, 489 hip->alloc_blocks, 490 start, len); 491 if (res == -ENOSPC) 492 goto insert_extent; 493 } 494 if (!res) { 495 hfsplus_dump_extent(hip->first_extents); 496 hip->first_blocks += len; 497 } 498 } else { 499 res = hfsplus_add_extent(hip->cached_extents, 500 hip->alloc_blocks - hip->cached_start, 501 start, len); 502 if (!res) { 503 hfsplus_dump_extent(hip->cached_extents); 504 hip->extent_state |= HFSPLUS_EXT_DIRTY; 505 hip->cached_blocks += len; 506 } else if (res == -ENOSPC) 507 goto insert_extent; 508 } 509 out: 510 if (!res) { 511 hip->alloc_blocks += len; 512 mutex_unlock(&hip->extents_lock); 513 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY); 514 return 0; 515 } 516 mutex_unlock(&hip->extents_lock); 517 return res; 518 519 insert_extent: 520 hfs_dbg(EXTENT, "insert new extent\n"); 521 res = hfsplus_ext_write_extent_locked(inode); 522 if (res) 523 goto out; 524 525 memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec)); 526 hip->cached_extents[0].start_block = cpu_to_be32(start); 527 hip->cached_extents[0].block_count = cpu_to_be32(len); 528 hfsplus_dump_extent(hip->cached_extents); 529 hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW; 530 hip->cached_start = hip->alloc_blocks; 531 hip->cached_blocks = len; 532 533 res = 0; 534 goto out; 535 } 536 537 void hfsplus_file_truncate(struct inode *inode) 538 { 539 struct super_block *sb = inode->i_sb; 540 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 541 struct hfs_find_data fd; 542 u32 alloc_cnt, blk_cnt, start; 543 int res; 544 545 hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n", 546 inode->i_ino, (long long)hip->phys_size, inode->i_size); 547 548 if (inode->i_size > hip->phys_size) { 549 struct address_space *mapping = inode->i_mapping; 550 struct page *page; 551 void *fsdata; 552 loff_t size = inode->i_size; 553 554 res = pagecache_write_begin(NULL, mapping, size, 0, 0, 555 &page, &fsdata); 556 if (res) 557 return; 558 res = pagecache_write_end(NULL, mapping, size, 559 0, 0, page, fsdata); 560 if (res < 0) 561 return; 562 mark_inode_dirty(inode); 563 return; 564 } else if (inode->i_size == hip->phys_size) 565 return; 566 567 blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >> 568 HFSPLUS_SB(sb)->alloc_blksz_shift; 569 570 mutex_lock(&hip->extents_lock); 571 572 alloc_cnt = hip->alloc_blocks; 573 if (blk_cnt == alloc_cnt) 574 goto out_unlock; 575 576 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd); 577 if (res) { 578 mutex_unlock(&hip->extents_lock); 579 /* XXX: We lack error handling of hfsplus_file_truncate() */ 580 return; 581 } 582 while (1) { 583 if (alloc_cnt == hip->first_blocks) { 584 mutex_unlock(&fd.tree->tree_lock); 585 hfsplus_free_extents(sb, hip->first_extents, 586 alloc_cnt, alloc_cnt - blk_cnt); 587 hfsplus_dump_extent(hip->first_extents); 588 hip->first_blocks = blk_cnt; 589 mutex_lock(&fd.tree->tree_lock); 590 break; 591 } 592 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt); 593 if (res) 594 break; 595 hfs_brec_remove(&fd); 596 597 mutex_unlock(&fd.tree->tree_lock); 598 start = hip->cached_start; 599 hfsplus_free_extents(sb, hip->cached_extents, 600 alloc_cnt - start, alloc_cnt - blk_cnt); 601 hfsplus_dump_extent(hip->cached_extents); 602 if (blk_cnt > start) { 603 hip->extent_state |= HFSPLUS_EXT_DIRTY; 604 break; 605 } 606 alloc_cnt = start; 607 hip->cached_start = hip->cached_blocks = 0; 608 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW); 609 mutex_lock(&fd.tree->tree_lock); 610 } 611 hfs_find_exit(&fd); 612 613 hip->alloc_blocks = blk_cnt; 614 out_unlock: 615 mutex_unlock(&hip->extents_lock); 616 hip->phys_size = inode->i_size; 617 hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> 618 sb->s_blocksize_bits; 619 inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits); 620 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY); 621 } 622