1// SPDX-License-Identifier: GPL-2.0 2/* 3 * linux/fs/hfsplus/bnode.c 4 * 5 * Copyright (C) 2001 6 * Brad Boyer (flar@allandria.com) 7 * (C) 2003 Ardis Technologies <roman@ardistech.com> 8 * 9 * Handle basic btree node operations 10 */ 11 12#include <linux/string.h> 13#include <linux/slab.h> 14#include <linux/pagemap.h> 15#include <linux/fs.h> 16#include <linux/swap.h> 17 18#include "hfsplus_fs.h" 19#include "hfsplus_raw.h" 20 21/* Copy a specified range of bytes from the raw data of a node */ 22void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len) 23{ 24 struct page **pagep; 25 int l; 26 27 off += node->page_offset; 28 pagep = node->page + (off >> PAGE_SHIFT); 29 off &= ~PAGE_MASK; 30 31 l = min_t(int, len, PAGE_SIZE - off); 32 memcpy(buf, kmap(*pagep) + off, l); 33 kunmap(*pagep); 34 35 while ((len -= l) != 0) { 36 buf += l; 37 l = min_t(int, len, PAGE_SIZE); 38 memcpy(buf, kmap(*++pagep), l); 39 kunmap(*pagep); 40 } 41} 42 43u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off) 44{ 45 __be16 data; 46 /* TODO: optimize later... */ 47 hfs_bnode_read(node, &data, off, 2); 48 return be16_to_cpu(data); 49} 50 51u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off) 52{ 53 u8 data; 54 /* TODO: optimize later... */ 55 hfs_bnode_read(node, &data, off, 1); 56 return data; 57} 58 59void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off) 60{ 61 struct hfs_btree *tree; 62 int key_len; 63 64 tree = node->tree; 65 if (node->type == HFS_NODE_LEAF || 66 tree->attributes & HFS_TREE_VARIDXKEYS || 67 node->tree->cnid == HFSPLUS_ATTR_CNID) 68 key_len = hfs_bnode_read_u16(node, off) + 2; 69 else 70 key_len = tree->max_key_len + 2; 71 72 hfs_bnode_read(node, key, off, key_len); 73} 74 75void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len) 76{ 77 struct page **pagep; 78 int l; 79 80 off += node->page_offset; 81 pagep = node->page + (off >> PAGE_SHIFT); 82 off &= ~PAGE_MASK; 83 84 l = min_t(int, len, PAGE_SIZE - off); 85 memcpy(kmap(*pagep) + off, buf, l); 86 set_page_dirty(*pagep); 87 kunmap(*pagep); 88 89 while ((len -= l) != 0) { 90 buf += l; 91 l = min_t(int, len, PAGE_SIZE); 92 memcpy(kmap(*++pagep), buf, l); 93 set_page_dirty(*pagep); 94 kunmap(*pagep); 95 } 96} 97 98void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data) 99{ 100 __be16 v = cpu_to_be16(data); 101 /* TODO: optimize later... */ 102 hfs_bnode_write(node, &v, off, 2); 103} 104 105void hfs_bnode_clear(struct hfs_bnode *node, int off, int len) 106{ 107 struct page **pagep; 108 int l; 109 110 off += node->page_offset; 111 pagep = node->page + (off >> PAGE_SHIFT); 112 off &= ~PAGE_MASK; 113 114 l = min_t(int, len, PAGE_SIZE - off); 115 memset(kmap(*pagep) + off, 0, l); 116 set_page_dirty(*pagep); 117 kunmap(*pagep); 118 119 while ((len -= l) != 0) { 120 l = min_t(int, len, PAGE_SIZE); 121 memset(kmap(*++pagep), 0, l); 122 set_page_dirty(*pagep); 123 kunmap(*pagep); 124 } 125} 126 127void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst, 128 struct hfs_bnode *src_node, int src, int len) 129{ 130 struct page **src_page, **dst_page; 131 int l; 132 133 hfs_dbg(BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len); 134 if (!len) 135 return; 136 src += src_node->page_offset; 137 dst += dst_node->page_offset; 138 src_page = src_node->page + (src >> PAGE_SHIFT); 139 src &= ~PAGE_MASK; 140 dst_page = dst_node->page + (dst >> PAGE_SHIFT); 141 dst &= ~PAGE_MASK; 142 143 if (src == dst) { 144 l = min_t(int, len, PAGE_SIZE - src); 145 memcpy(kmap(*dst_page) + src, kmap(*src_page) + src, l); 146 kunmap(*src_page); 147 set_page_dirty(*dst_page); 148 kunmap(*dst_page); 149 150 while ((len -= l) != 0) { 151 l = min_t(int, len, PAGE_SIZE); 152 memcpy(kmap(*++dst_page), kmap(*++src_page), l); 153 kunmap(*src_page); 154 set_page_dirty(*dst_page); 155 kunmap(*dst_page); 156 } 157 } else { 158 void *src_ptr, *dst_ptr; 159 160 do { 161 src_ptr = kmap(*src_page) + src; 162 dst_ptr = kmap(*dst_page) + dst; 163 if (PAGE_SIZE - src < PAGE_SIZE - dst) { 164 l = PAGE_SIZE - src; 165 src = 0; 166 dst += l; 167 } else { 168 l = PAGE_SIZE - dst; 169 src += l; 170 dst = 0; 171 } 172 l = min(len, l); 173 memcpy(dst_ptr, src_ptr, l); 174 kunmap(*src_page); 175 set_page_dirty(*dst_page); 176 kunmap(*dst_page); 177 if (!dst) 178 dst_page++; 179 else 180 src_page++; 181 } while ((len -= l)); 182 } 183} 184 185void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len) 186{ 187 struct page **src_page, **dst_page; 188 int l; 189 190 hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len); 191 if (!len) 192 return; 193 src += node->page_offset; 194 dst += node->page_offset; 195 if (dst > src) { 196 src += len - 1; 197 src_page = node->page + (src >> PAGE_SHIFT); 198 src = (src & ~PAGE_MASK) + 1; 199 dst += len - 1; 200 dst_page = node->page + (dst >> PAGE_SHIFT); 201 dst = (dst & ~PAGE_MASK) + 1; 202 203 if (src == dst) { 204 while (src < len) { 205 memmove(kmap(*dst_page), kmap(*src_page), src); 206 kunmap(*src_page); 207 set_page_dirty(*dst_page); 208 kunmap(*dst_page); 209 len -= src; 210 src = PAGE_SIZE; 211 src_page--; 212 dst_page--; 213 } 214 src -= len; 215 memmove(kmap(*dst_page) + src, 216 kmap(*src_page) + src, len); 217 kunmap(*src_page); 218 set_page_dirty(*dst_page); 219 kunmap(*dst_page); 220 } else { 221 void *src_ptr, *dst_ptr; 222 223 do { 224 src_ptr = kmap(*src_page) + src; 225 dst_ptr = kmap(*dst_page) + dst; 226 if (src < dst) { 227 l = src; 228 src = PAGE_SIZE; 229 dst -= l; 230 } else { 231 l = dst; 232 src -= l; 233 dst = PAGE_SIZE; 234 } 235 l = min(len, l); 236 memmove(dst_ptr - l, src_ptr - l, l); 237 kunmap(*src_page); 238 set_page_dirty(*dst_page); 239 kunmap(*dst_page); 240 if (dst == PAGE_SIZE) 241 dst_page--; 242 else 243 src_page--; 244 } while ((len -= l)); 245 } 246 } else { 247 src_page = node->page + (src >> PAGE_SHIFT); 248 src &= ~PAGE_MASK; 249 dst_page = node->page + (dst >> PAGE_SHIFT); 250 dst &= ~PAGE_MASK; 251 252 if (src == dst) { 253 l = min_t(int, len, PAGE_SIZE - src); 254 memmove(kmap(*dst_page) + src, 255 kmap(*src_page) + src, l); 256 kunmap(*src_page); 257 set_page_dirty(*dst_page); 258 kunmap(*dst_page); 259 260 while ((len -= l) != 0) { 261 l = min_t(int, len, PAGE_SIZE); 262 memmove(kmap(*++dst_page), 263 kmap(*++src_page), l); 264 kunmap(*src_page); 265 set_page_dirty(*dst_page); 266 kunmap(*dst_page); 267 } 268 } else { 269 void *src_ptr, *dst_ptr; 270 271 do { 272 src_ptr = kmap(*src_page) + src; 273 dst_ptr = kmap(*dst_page) + dst; 274 if (PAGE_SIZE - src < 275 PAGE_SIZE - dst) { 276 l = PAGE_SIZE - src; 277 src = 0; 278 dst += l; 279 } else { 280 l = PAGE_SIZE - dst; 281 src += l; 282 dst = 0; 283 } 284 l = min(len, l); 285 memmove(dst_ptr, src_ptr, l); 286 kunmap(*src_page); 287 set_page_dirty(*dst_page); 288 kunmap(*dst_page); 289 if (!dst) 290 dst_page++; 291 else 292 src_page++; 293 } while ((len -= l)); 294 } 295 } 296} 297 298void hfs_bnode_dump(struct hfs_bnode *node) 299{ 300 struct hfs_bnode_desc desc; 301 __be32 cnid; 302 int i, off, key_off; 303 304 hfs_dbg(BNODE_MOD, "bnode: %d\n", node->this); 305 hfs_bnode_read(node, &desc, 0, sizeof(desc)); 306 hfs_dbg(BNODE_MOD, "%d, %d, %d, %d, %d\n", 307 be32_to_cpu(desc.next), be32_to_cpu(desc.prev), 308 desc.type, desc.height, be16_to_cpu(desc.num_recs)); 309 310 off = node->tree->node_size - 2; 311 for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) { 312 key_off = hfs_bnode_read_u16(node, off); 313 hfs_dbg(BNODE_MOD, " %d", key_off); 314 if (i && node->type == HFS_NODE_INDEX) { 315 int tmp; 316 317 if (node->tree->attributes & HFS_TREE_VARIDXKEYS || 318 node->tree->cnid == HFSPLUS_ATTR_CNID) 319 tmp = hfs_bnode_read_u16(node, key_off) + 2; 320 else 321 tmp = node->tree->max_key_len + 2; 322 hfs_dbg_cont(BNODE_MOD, " (%d", tmp); 323 hfs_bnode_read(node, &cnid, key_off + tmp, 4); 324 hfs_dbg_cont(BNODE_MOD, ",%d)", be32_to_cpu(cnid)); 325 } else if (i && node->type == HFS_NODE_LEAF) { 326 int tmp; 327 328 tmp = hfs_bnode_read_u16(node, key_off); 329 hfs_dbg_cont(BNODE_MOD, " (%d)", tmp); 330 } 331 } 332 hfs_dbg_cont(BNODE_MOD, "\n"); 333} 334 335void hfs_bnode_unlink(struct hfs_bnode *node) 336{ 337 struct hfs_btree *tree; 338 struct hfs_bnode *tmp; 339 __be32 cnid; 340 341 tree = node->tree; 342 if (node->prev) { 343 tmp = hfs_bnode_find(tree, node->prev); 344 if (IS_ERR(tmp)) 345 return; 346 tmp->next = node->next; 347 cnid = cpu_to_be32(tmp->next); 348 hfs_bnode_write(tmp, &cnid, 349 offsetof(struct hfs_bnode_desc, next), 4); 350 hfs_bnode_put(tmp); 351 } else if (node->type == HFS_NODE_LEAF) 352 tree->leaf_head = node->next; 353 354 if (node->next) { 355 tmp = hfs_bnode_find(tree, node->next); 356 if (IS_ERR(tmp)) 357 return; 358 tmp->prev = node->prev; 359 cnid = cpu_to_be32(tmp->prev); 360 hfs_bnode_write(tmp, &cnid, 361 offsetof(struct hfs_bnode_desc, prev), 4); 362 hfs_bnode_put(tmp); 363 } else if (node->type == HFS_NODE_LEAF) 364 tree->leaf_tail = node->prev; 365 366 /* move down? */ 367 if (!node->prev && !node->next) 368 hfs_dbg(BNODE_MOD, "hfs_btree_del_level\n"); 369 if (!node->parent) { 370 tree->root = 0; 371 tree->depth = 0; 372 } 373 set_bit(HFS_BNODE_DELETED, &node->flags); 374} 375 376static inline int hfs_bnode_hash(u32 num) 377{ 378 num = (num >> 16) + num; 379 num += num >> 8; 380 return num & (NODE_HASH_SIZE - 1); 381} 382 383struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid) 384{ 385 struct hfs_bnode *node; 386 387 if (cnid >= tree->node_count) { 388 pr_err("request for non-existent node %d in B*Tree\n", 389 cnid); 390 return NULL; 391 } 392 393 for (node = tree->node_hash[hfs_bnode_hash(cnid)]; 394 node; node = node->next_hash) 395 if (node->this == cnid) 396 return node; 397 return NULL; 398} 399 400static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid) 401{ 402 struct hfs_bnode *node, *node2; 403 struct address_space *mapping; 404 struct page *page; 405 int size, block, i, hash; 406 loff_t off; 407 408 if (cnid >= tree->node_count) { 409 pr_err("request for non-existent node %d in B*Tree\n", 410 cnid); 411 return NULL; 412 } 413 414 size = sizeof(struct hfs_bnode) + tree->pages_per_bnode * 415 sizeof(struct page *); 416 node = kzalloc(size, GFP_KERNEL); 417 if (!node) 418 return NULL; 419 node->tree = tree; 420 node->this = cnid; 421 set_bit(HFS_BNODE_NEW, &node->flags); 422 atomic_set(&node->refcnt, 1); 423 hfs_dbg(BNODE_REFS, "new_node(%d:%d): 1\n", 424 node->tree->cnid, node->this); 425 init_waitqueue_head(&node->lock_wq); 426 spin_lock(&tree->hash_lock); 427 node2 = hfs_bnode_findhash(tree, cnid); 428 if (!node2) { 429 hash = hfs_bnode_hash(cnid); 430 node->next_hash = tree->node_hash[hash]; 431 tree->node_hash[hash] = node; 432 tree->node_hash_cnt++; 433 } else { 434 spin_unlock(&tree->hash_lock); 435 kfree(node); 436 wait_event(node2->lock_wq, 437 !test_bit(HFS_BNODE_NEW, &node2->flags)); 438 return node2; 439 } 440 spin_unlock(&tree->hash_lock); 441 442 mapping = tree->inode->i_mapping; 443 off = (loff_t)cnid << tree->node_size_shift; 444 block = off >> PAGE_SHIFT; 445 node->page_offset = off & ~PAGE_MASK; 446 for (i = 0; i < tree->pages_per_bnode; block++, i++) { 447 page = read_mapping_page(mapping, block, NULL); 448 if (IS_ERR(page)) 449 goto fail; 450 if (PageError(page)) { 451 put_page(page); 452 goto fail; 453 } 454 node->page[i] = page; 455 } 456 457 return node; 458fail: 459 set_bit(HFS_BNODE_ERROR, &node->flags); 460 return node; 461} 462 463void hfs_bnode_unhash(struct hfs_bnode *node) 464{ 465 struct hfs_bnode **p; 466 467 hfs_dbg(BNODE_REFS, "remove_node(%d:%d): %d\n", 468 node->tree->cnid, node->this, atomic_read(&node->refcnt)); 469 for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)]; 470 *p && *p != node; p = &(*p)->next_hash) 471 ; 472 BUG_ON(!*p); 473 *p = node->next_hash; 474 node->tree->node_hash_cnt--; 475} 476 477/* Load a particular node out of a tree */ 478struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num) 479{ 480 struct hfs_bnode *node; 481 struct hfs_bnode_desc *desc; 482 int i, rec_off, off, next_off; 483 int entry_size, key_size; 484 485 spin_lock(&tree->hash_lock); 486 node = hfs_bnode_findhash(tree, num); 487 if (node) { 488 hfs_bnode_get(node); 489 spin_unlock(&tree->hash_lock); 490 wait_event(node->lock_wq, 491 !test_bit(HFS_BNODE_NEW, &node->flags)); 492 if (test_bit(HFS_BNODE_ERROR, &node->flags)) 493 goto node_error; 494 return node; 495 } 496 spin_unlock(&tree->hash_lock); 497 node = __hfs_bnode_create(tree, num); 498 if (!node) 499 return ERR_PTR(-ENOMEM); 500 if (test_bit(HFS_BNODE_ERROR, &node->flags)) 501 goto node_error; 502 if (!test_bit(HFS_BNODE_NEW, &node->flags)) 503 return node; 504 505 desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + 506 node->page_offset); 507 node->prev = be32_to_cpu(desc->prev); 508 node->next = be32_to_cpu(desc->next); 509 node->num_recs = be16_to_cpu(desc->num_recs); 510 node->type = desc->type; 511 node->height = desc->height; 512 kunmap(node->page[0]); 513 514 switch (node->type) { 515 case HFS_NODE_HEADER: 516 case HFS_NODE_MAP: 517 if (node->height != 0) 518 goto node_error; 519 break; 520 case HFS_NODE_LEAF: 521 if (node->height != 1) 522 goto node_error; 523 break; 524 case HFS_NODE_INDEX: 525 if (node->height <= 1 || node->height > tree->depth) 526 goto node_error; 527 break; 528 default: 529 goto node_error; 530 } 531 532 rec_off = tree->node_size - 2; 533 off = hfs_bnode_read_u16(node, rec_off); 534 if (off != sizeof(struct hfs_bnode_desc)) 535 goto node_error; 536 for (i = 1; i <= node->num_recs; off = next_off, i++) { 537 rec_off -= 2; 538 next_off = hfs_bnode_read_u16(node, rec_off); 539 if (next_off <= off || 540 next_off > tree->node_size || 541 next_off & 1) 542 goto node_error; 543 entry_size = next_off - off; 544 if (node->type != HFS_NODE_INDEX && 545 node->type != HFS_NODE_LEAF) 546 continue; 547 key_size = hfs_bnode_read_u16(node, off) + 2; 548 if (key_size >= entry_size || key_size & 1) 549 goto node_error; 550 } 551 clear_bit(HFS_BNODE_NEW, &node->flags); 552 wake_up(&node->lock_wq); 553 return node; 554 555node_error: 556 set_bit(HFS_BNODE_ERROR, &node->flags); 557 clear_bit(HFS_BNODE_NEW, &node->flags); 558 wake_up(&node->lock_wq); 559 hfs_bnode_put(node); 560 return ERR_PTR(-EIO); 561} 562 563void hfs_bnode_free(struct hfs_bnode *node) 564{ 565 int i; 566 567 for (i = 0; i < node->tree->pages_per_bnode; i++) 568 if (node->page[i]) 569 put_page(node->page[i]); 570 kfree(node); 571} 572 573struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num) 574{ 575 struct hfs_bnode *node; 576 struct page **pagep; 577 int i; 578 579 spin_lock(&tree->hash_lock); 580 node = hfs_bnode_findhash(tree, num); 581 spin_unlock(&tree->hash_lock); 582 if (node) { 583 pr_crit("new node %u already hashed?\n", num); 584 WARN_ON(1); 585 return node; 586 } 587 node = __hfs_bnode_create(tree, num); 588 if (!node) 589 return ERR_PTR(-ENOMEM); 590 if (test_bit(HFS_BNODE_ERROR, &node->flags)) { 591 hfs_bnode_put(node); 592 return ERR_PTR(-EIO); 593 } 594 595 pagep = node->page; 596 memset(kmap(*pagep) + node->page_offset, 0, 597 min_t(int, PAGE_SIZE, tree->node_size)); 598 set_page_dirty(*pagep); 599 kunmap(*pagep); 600 for (i = 1; i < tree->pages_per_bnode; i++) { 601 memset(kmap(*++pagep), 0, PAGE_SIZE); 602 set_page_dirty(*pagep); 603 kunmap(*pagep); 604 } 605 clear_bit(HFS_BNODE_NEW, &node->flags); 606 wake_up(&node->lock_wq); 607 608 return node; 609} 610 611void hfs_bnode_get(struct hfs_bnode *node) 612{ 613 if (node) { 614 atomic_inc(&node->refcnt); 615 hfs_dbg(BNODE_REFS, "get_node(%d:%d): %d\n", 616 node->tree->cnid, node->this, 617 atomic_read(&node->refcnt)); 618 } 619} 620 621/* Dispose of resources used by a node */ 622void hfs_bnode_put(struct hfs_bnode *node) 623{ 624 if (node) { 625 struct hfs_btree *tree = node->tree; 626 int i; 627 628 hfs_dbg(BNODE_REFS, "put_node(%d:%d): %d\n", 629 node->tree->cnid, node->this, 630 atomic_read(&node->refcnt)); 631 BUG_ON(!atomic_read(&node->refcnt)); 632 if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock)) 633 return; 634 for (i = 0; i < tree->pages_per_bnode; i++) { 635 if (!node->page[i]) 636 continue; 637 mark_page_accessed(node->page[i]); 638 } 639 640 if (test_bit(HFS_BNODE_DELETED, &node->flags)) { 641 hfs_bnode_unhash(node); 642 spin_unlock(&tree->hash_lock); 643 if (hfs_bnode_need_zeroout(tree)) 644 hfs_bnode_clear(node, 0, tree->node_size); 645 hfs_bmap_free(node); 646 hfs_bnode_free(node); 647 return; 648 } 649 spin_unlock(&tree->hash_lock); 650 } 651} 652 653/* 654 * Unused nodes have to be zeroed if this is the catalog tree and 655 * a corresponding flag in the volume header is set. 656 */ 657bool hfs_bnode_need_zeroout(struct hfs_btree *tree) 658{ 659 struct super_block *sb = tree->inode->i_sb; 660 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); 661 const u32 volume_attr = be32_to_cpu(sbi->s_vhdr->attributes); 662 663 return tree->cnid == HFSPLUS_CAT_CNID && 664 volume_attr & HFSPLUS_VOL_UNUSED_NODE_FIX; 665} 666