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 /* Fail early and avoid ENOSPC during the btree operation */ 104 res = hfs_bmap_reserve(fd->tree, fd->tree->depth + 1); 105 if (res) 106 return res; 107 hfs_brec_insert(fd, hip->cached_extents, 108 sizeof(hfsplus_extent_rec)); 109 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW); 110 } else { 111 if (res) 112 return res; 113 hfs_bnode_write(fd->bnode, hip->cached_extents, 114 fd->entryoffset, fd->entrylength); 115 hip->extent_state &= ~HFSPLUS_EXT_DIRTY; 116 } 117 118 /* 119 * We can't just use hfsplus_mark_inode_dirty here, because we 120 * also get called from hfsplus_write_inode, which should not 121 * redirty the inode. Instead the callers have to be careful 122 * to explicily mark the inode dirty, too. 123 */ 124 set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags); 125 126 return 0; 127 } 128 129 static int hfsplus_ext_write_extent_locked(struct inode *inode) 130 { 131 int res = 0; 132 133 if (HFSPLUS_I(inode)->extent_state & HFSPLUS_EXT_DIRTY) { 134 struct hfs_find_data fd; 135 136 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd); 137 if (res) 138 return res; 139 res = __hfsplus_ext_write_extent(inode, &fd); 140 hfs_find_exit(&fd); 141 } 142 return res; 143 } 144 145 int hfsplus_ext_write_extent(struct inode *inode) 146 { 147 int res; 148 149 mutex_lock(&HFSPLUS_I(inode)->extents_lock); 150 res = hfsplus_ext_write_extent_locked(inode); 151 mutex_unlock(&HFSPLUS_I(inode)->extents_lock); 152 153 return res; 154 } 155 156 static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd, 157 struct hfsplus_extent *extent, 158 u32 cnid, u32 block, u8 type) 159 { 160 int res; 161 162 hfsplus_ext_build_key(fd->search_key, cnid, block, type); 163 fd->key->ext.cnid = 0; 164 res = hfs_brec_find(fd, hfs_find_rec_by_key); 165 if (res && res != -ENOENT) 166 return res; 167 if (fd->key->ext.cnid != fd->search_key->ext.cnid || 168 fd->key->ext.fork_type != fd->search_key->ext.fork_type) 169 return -ENOENT; 170 if (fd->entrylength != sizeof(hfsplus_extent_rec)) 171 return -EIO; 172 hfs_bnode_read(fd->bnode, extent, fd->entryoffset, 173 sizeof(hfsplus_extent_rec)); 174 return 0; 175 } 176 177 static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, 178 struct inode *inode, u32 block) 179 { 180 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 181 int res; 182 183 WARN_ON(!mutex_is_locked(&hip->extents_lock)); 184 185 if (hip->extent_state & HFSPLUS_EXT_DIRTY) { 186 res = __hfsplus_ext_write_extent(inode, fd); 187 if (res) 188 return res; 189 } 190 191 res = __hfsplus_ext_read_extent(fd, hip->cached_extents, inode->i_ino, 192 block, HFSPLUS_IS_RSRC(inode) ? 193 HFSPLUS_TYPE_RSRC : 194 HFSPLUS_TYPE_DATA); 195 if (!res) { 196 hip->cached_start = be32_to_cpu(fd->key->ext.start_block); 197 hip->cached_blocks = 198 hfsplus_ext_block_count(hip->cached_extents); 199 } else { 200 hip->cached_start = hip->cached_blocks = 0; 201 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW); 202 } 203 return res; 204 } 205 206 static int hfsplus_ext_read_extent(struct inode *inode, u32 block) 207 { 208 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 209 struct hfs_find_data fd; 210 int res; 211 212 if (block >= hip->cached_start && 213 block < hip->cached_start + hip->cached_blocks) 214 return 0; 215 216 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->ext_tree, &fd); 217 if (!res) { 218 res = __hfsplus_ext_cache_extent(&fd, inode, block); 219 hfs_find_exit(&fd); 220 } 221 return res; 222 } 223 224 /* Get a block at iblock for inode, possibly allocating if create */ 225 int hfsplus_get_block(struct inode *inode, sector_t iblock, 226 struct buffer_head *bh_result, int create) 227 { 228 struct super_block *sb = inode->i_sb; 229 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); 230 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 231 int res = -EIO; 232 u32 ablock, dblock, mask; 233 sector_t sector; 234 int was_dirty = 0; 235 236 /* Convert inode block to disk allocation block */ 237 ablock = iblock >> sbi->fs_shift; 238 239 if (iblock >= hip->fs_blocks) { 240 if (!create) 241 return 0; 242 if (iblock > hip->fs_blocks) 243 return -EIO; 244 if (ablock >= hip->alloc_blocks) { 245 res = hfsplus_file_extend(inode, false); 246 if (res) 247 return res; 248 } 249 } else 250 create = 0; 251 252 if (ablock < hip->first_blocks) { 253 dblock = hfsplus_ext_find_block(hip->first_extents, ablock); 254 goto done; 255 } 256 257 if (inode->i_ino == HFSPLUS_EXT_CNID) 258 return -EIO; 259 260 mutex_lock(&hip->extents_lock); 261 262 /* 263 * hfsplus_ext_read_extent will write out a cached extent into 264 * the extents btree. In that case we may have to mark the inode 265 * dirty even for a pure read of an extent here. 266 */ 267 was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY); 268 res = hfsplus_ext_read_extent(inode, ablock); 269 if (res) { 270 mutex_unlock(&hip->extents_lock); 271 return -EIO; 272 } 273 dblock = hfsplus_ext_find_block(hip->cached_extents, 274 ablock - hip->cached_start); 275 mutex_unlock(&hip->extents_lock); 276 277 done: 278 hfs_dbg(EXTENT, "get_block(%lu): %llu - %u\n", 279 inode->i_ino, (long long)iblock, dblock); 280 281 mask = (1 << sbi->fs_shift) - 1; 282 sector = ((sector_t)dblock << sbi->fs_shift) + 283 sbi->blockoffset + (iblock & mask); 284 map_bh(bh_result, sb, sector); 285 286 if (create) { 287 set_buffer_new(bh_result); 288 hip->phys_size += sb->s_blocksize; 289 hip->fs_blocks++; 290 inode_add_bytes(inode, sb->s_blocksize); 291 } 292 if (create || was_dirty) 293 mark_inode_dirty(inode); 294 return 0; 295 } 296 297 static void hfsplus_dump_extent(struct hfsplus_extent *extent) 298 { 299 int i; 300 301 hfs_dbg(EXTENT, " "); 302 for (i = 0; i < 8; i++) 303 hfs_dbg_cont(EXTENT, " %u:%u", 304 be32_to_cpu(extent[i].start_block), 305 be32_to_cpu(extent[i].block_count)); 306 hfs_dbg_cont(EXTENT, "\n"); 307 } 308 309 static int hfsplus_add_extent(struct hfsplus_extent *extent, u32 offset, 310 u32 alloc_block, u32 block_count) 311 { 312 u32 count, start; 313 int i; 314 315 hfsplus_dump_extent(extent); 316 for (i = 0; i < 8; extent++, i++) { 317 count = be32_to_cpu(extent->block_count); 318 if (offset == count) { 319 start = be32_to_cpu(extent->start_block); 320 if (alloc_block != start + count) { 321 if (++i >= 8) 322 return -ENOSPC; 323 extent++; 324 extent->start_block = cpu_to_be32(alloc_block); 325 } else 326 block_count += count; 327 extent->block_count = cpu_to_be32(block_count); 328 return 0; 329 } else if (offset < count) 330 break; 331 offset -= count; 332 } 333 /* panic? */ 334 return -EIO; 335 } 336 337 static int hfsplus_free_extents(struct super_block *sb, 338 struct hfsplus_extent *extent, 339 u32 offset, u32 block_nr) 340 { 341 u32 count, start; 342 int i; 343 int err = 0; 344 345 /* Mapping the allocation file may lock the extent tree */ 346 WARN_ON(mutex_is_locked(&HFSPLUS_SB(sb)->ext_tree->tree_lock)); 347 348 hfsplus_dump_extent(extent); 349 for (i = 0; i < 8; extent++, i++) { 350 count = be32_to_cpu(extent->block_count); 351 if (offset == count) 352 goto found; 353 else if (offset < count) 354 break; 355 offset -= count; 356 } 357 /* panic? */ 358 return -EIO; 359 found: 360 for (;;) { 361 start = be32_to_cpu(extent->start_block); 362 if (count <= block_nr) { 363 err = hfsplus_block_free(sb, start, count); 364 if (err) { 365 pr_err("can't free extent\n"); 366 hfs_dbg(EXTENT, " start: %u count: %u\n", 367 start, count); 368 } 369 extent->block_count = 0; 370 extent->start_block = 0; 371 block_nr -= count; 372 } else { 373 count -= block_nr; 374 err = hfsplus_block_free(sb, start + count, block_nr); 375 if (err) { 376 pr_err("can't free extent\n"); 377 hfs_dbg(EXTENT, " start: %u count: %u\n", 378 start, count); 379 } 380 extent->block_count = cpu_to_be32(count); 381 block_nr = 0; 382 } 383 if (!block_nr || !i) { 384 /* 385 * Try to free all extents and 386 * return only last error 387 */ 388 return err; 389 } 390 i--; 391 extent--; 392 count = be32_to_cpu(extent->block_count); 393 } 394 } 395 396 int hfsplus_free_fork(struct super_block *sb, u32 cnid, 397 struct hfsplus_fork_raw *fork, int type) 398 { 399 struct hfs_find_data fd; 400 hfsplus_extent_rec ext_entry; 401 u32 total_blocks, blocks, start; 402 int res, i; 403 404 total_blocks = be32_to_cpu(fork->total_blocks); 405 if (!total_blocks) 406 return 0; 407 408 blocks = 0; 409 for (i = 0; i < 8; i++) 410 blocks += be32_to_cpu(fork->extents[i].block_count); 411 412 res = hfsplus_free_extents(sb, fork->extents, blocks, blocks); 413 if (res) 414 return res; 415 if (total_blocks == blocks) 416 return 0; 417 418 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd); 419 if (res) 420 return res; 421 do { 422 res = __hfsplus_ext_read_extent(&fd, ext_entry, cnid, 423 total_blocks, type); 424 if (res) 425 break; 426 start = be32_to_cpu(fd.key->ext.start_block); 427 hfs_brec_remove(&fd); 428 429 mutex_unlock(&fd.tree->tree_lock); 430 hfsplus_free_extents(sb, ext_entry, total_blocks - start, 431 total_blocks); 432 total_blocks = start; 433 mutex_lock_nested(&fd.tree->tree_lock, 434 hfsplus_btree_lock_class(fd.tree)); 435 } while (total_blocks > blocks); 436 hfs_find_exit(&fd); 437 438 return res; 439 } 440 441 int hfsplus_file_extend(struct inode *inode, bool zeroout) 442 { 443 struct super_block *sb = inode->i_sb; 444 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); 445 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 446 u32 start, len, goal; 447 int res; 448 449 if (sbi->alloc_file->i_size * 8 < 450 sbi->total_blocks - sbi->free_blocks + 8) { 451 /* extend alloc file */ 452 pr_err_ratelimited("extend alloc file! (%llu,%u,%u)\n", 453 sbi->alloc_file->i_size * 8, 454 sbi->total_blocks, sbi->free_blocks); 455 return -ENOSPC; 456 } 457 458 mutex_lock(&hip->extents_lock); 459 if (hip->alloc_blocks == hip->first_blocks) 460 goal = hfsplus_ext_lastblock(hip->first_extents); 461 else { 462 res = hfsplus_ext_read_extent(inode, hip->alloc_blocks); 463 if (res) 464 goto out; 465 goal = hfsplus_ext_lastblock(hip->cached_extents); 466 } 467 468 len = hip->clump_blocks; 469 start = hfsplus_block_allocate(sb, sbi->total_blocks, goal, &len); 470 if (start >= sbi->total_blocks) { 471 start = hfsplus_block_allocate(sb, goal, 0, &len); 472 if (start >= goal) { 473 res = -ENOSPC; 474 goto out; 475 } 476 } 477 478 if (zeroout) { 479 res = sb_issue_zeroout(sb, start, len, GFP_NOFS); 480 if (res) 481 goto out; 482 } 483 484 hfs_dbg(EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len); 485 486 if (hip->alloc_blocks <= hip->first_blocks) { 487 if (!hip->first_blocks) { 488 hfs_dbg(EXTENT, "first extents\n"); 489 /* no extents yet */ 490 hip->first_extents[0].start_block = cpu_to_be32(start); 491 hip->first_extents[0].block_count = cpu_to_be32(len); 492 res = 0; 493 } else { 494 /* try to append to extents in inode */ 495 res = hfsplus_add_extent(hip->first_extents, 496 hip->alloc_blocks, 497 start, len); 498 if (res == -ENOSPC) 499 goto insert_extent; 500 } 501 if (!res) { 502 hfsplus_dump_extent(hip->first_extents); 503 hip->first_blocks += len; 504 } 505 } else { 506 res = hfsplus_add_extent(hip->cached_extents, 507 hip->alloc_blocks - hip->cached_start, 508 start, len); 509 if (!res) { 510 hfsplus_dump_extent(hip->cached_extents); 511 hip->extent_state |= HFSPLUS_EXT_DIRTY; 512 hip->cached_blocks += len; 513 } else if (res == -ENOSPC) 514 goto insert_extent; 515 } 516 out: 517 if (!res) { 518 hip->alloc_blocks += len; 519 mutex_unlock(&hip->extents_lock); 520 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY); 521 return 0; 522 } 523 mutex_unlock(&hip->extents_lock); 524 return res; 525 526 insert_extent: 527 hfs_dbg(EXTENT, "insert new extent\n"); 528 res = hfsplus_ext_write_extent_locked(inode); 529 if (res) 530 goto out; 531 532 memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec)); 533 hip->cached_extents[0].start_block = cpu_to_be32(start); 534 hip->cached_extents[0].block_count = cpu_to_be32(len); 535 hfsplus_dump_extent(hip->cached_extents); 536 hip->extent_state |= HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW; 537 hip->cached_start = hip->alloc_blocks; 538 hip->cached_blocks = len; 539 540 res = 0; 541 goto out; 542 } 543 544 void hfsplus_file_truncate(struct inode *inode) 545 { 546 struct super_block *sb = inode->i_sb; 547 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 548 struct hfs_find_data fd; 549 u32 alloc_cnt, blk_cnt, start; 550 int res; 551 552 hfs_dbg(INODE, "truncate: %lu, %llu -> %llu\n", 553 inode->i_ino, (long long)hip->phys_size, inode->i_size); 554 555 if (inode->i_size > hip->phys_size) { 556 struct address_space *mapping = inode->i_mapping; 557 struct page *page; 558 void *fsdata = NULL; 559 loff_t size = inode->i_size; 560 561 res = hfsplus_write_begin(NULL, mapping, size, 0, 562 &page, &fsdata); 563 if (res) 564 return; 565 res = generic_write_end(NULL, mapping, size, 0, 0, 566 page, fsdata); 567 if (res < 0) 568 return; 569 mark_inode_dirty(inode); 570 return; 571 } else if (inode->i_size == hip->phys_size) 572 return; 573 574 blk_cnt = (inode->i_size + HFSPLUS_SB(sb)->alloc_blksz - 1) >> 575 HFSPLUS_SB(sb)->alloc_blksz_shift; 576 577 mutex_lock(&hip->extents_lock); 578 579 alloc_cnt = hip->alloc_blocks; 580 if (blk_cnt == alloc_cnt) 581 goto out_unlock; 582 583 res = hfs_find_init(HFSPLUS_SB(sb)->ext_tree, &fd); 584 if (res) { 585 mutex_unlock(&hip->extents_lock); 586 /* XXX: We lack error handling of hfsplus_file_truncate() */ 587 return; 588 } 589 while (1) { 590 if (alloc_cnt == hip->first_blocks) { 591 mutex_unlock(&fd.tree->tree_lock); 592 hfsplus_free_extents(sb, hip->first_extents, 593 alloc_cnt, alloc_cnt - blk_cnt); 594 hfsplus_dump_extent(hip->first_extents); 595 hip->first_blocks = blk_cnt; 596 mutex_lock_nested(&fd.tree->tree_lock, 597 hfsplus_btree_lock_class(fd.tree)); 598 break; 599 } 600 res = __hfsplus_ext_cache_extent(&fd, inode, alloc_cnt); 601 if (res) 602 break; 603 604 start = hip->cached_start; 605 if (blk_cnt <= start) 606 hfs_brec_remove(&fd); 607 mutex_unlock(&fd.tree->tree_lock); 608 hfsplus_free_extents(sb, hip->cached_extents, 609 alloc_cnt - start, alloc_cnt - blk_cnt); 610 hfsplus_dump_extent(hip->cached_extents); 611 mutex_lock_nested(&fd.tree->tree_lock, 612 hfsplus_btree_lock_class(fd.tree)); 613 if (blk_cnt > start) { 614 hip->extent_state |= HFSPLUS_EXT_DIRTY; 615 break; 616 } 617 alloc_cnt = start; 618 hip->cached_start = hip->cached_blocks = 0; 619 hip->extent_state &= ~(HFSPLUS_EXT_DIRTY | HFSPLUS_EXT_NEW); 620 } 621 hfs_find_exit(&fd); 622 623 hip->alloc_blocks = blk_cnt; 624 out_unlock: 625 mutex_unlock(&hip->extents_lock); 626 hip->phys_size = inode->i_size; 627 hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> 628 sb->s_blocksize_bits; 629 inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits); 630 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY); 631 } 632