1 /* 2 * linux/fs/hfsplus/bnode.c 3 * 4 * Copyright (C) 2001 5 * Brad Boyer (flar@allandria.com) 6 * (C) 2003 Ardis Technologies <roman@ardistech.com> 7 * 8 * Handle basic btree node operations 9 */ 10 11 #include <linux/string.h> 12 #include <linux/slab.h> 13 #include <linux/pagemap.h> 14 #include <linux/fs.h> 15 #include <linux/swap.h> 16 17 #include "hfsplus_fs.h" 18 #include "hfsplus_raw.h" 19 20 /* Copy a specified range of bytes from the raw data of a node */ 21 void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len) 22 { 23 struct page **pagep; 24 int l; 25 26 off += node->page_offset; 27 pagep = node->page + (off >> PAGE_CACHE_SHIFT); 28 off &= ~PAGE_CACHE_MASK; 29 30 l = min(len, (int)PAGE_CACHE_SIZE - off); 31 memcpy(buf, kmap(*pagep) + off, l); 32 kunmap(*pagep); 33 34 while ((len -= l) != 0) { 35 buf += l; 36 l = min(len, (int)PAGE_CACHE_SIZE); 37 memcpy(buf, kmap(*++pagep), l); 38 kunmap(*pagep); 39 } 40 } 41 42 u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off) 43 { 44 __be16 data; 45 /* TODO: optimize later... */ 46 hfs_bnode_read(node, &data, off, 2); 47 return be16_to_cpu(data); 48 } 49 50 u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off) 51 { 52 u8 data; 53 /* TODO: optimize later... */ 54 hfs_bnode_read(node, &data, off, 1); 55 return data; 56 } 57 58 void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off) 59 { 60 struct hfs_btree *tree; 61 int key_len; 62 63 tree = node->tree; 64 if (node->type == HFS_NODE_LEAF || 65 tree->attributes & HFS_TREE_VARIDXKEYS) 66 key_len = hfs_bnode_read_u16(node, off) + 2; 67 else 68 key_len = tree->max_key_len + 2; 69 70 hfs_bnode_read(node, key, off, key_len); 71 } 72 73 void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len) 74 { 75 struct page **pagep; 76 int l; 77 78 off += node->page_offset; 79 pagep = node->page + (off >> PAGE_CACHE_SHIFT); 80 off &= ~PAGE_CACHE_MASK; 81 82 l = min(len, (int)PAGE_CACHE_SIZE - off); 83 memcpy(kmap(*pagep) + off, buf, l); 84 set_page_dirty(*pagep); 85 kunmap(*pagep); 86 87 while ((len -= l) != 0) { 88 buf += l; 89 l = min(len, (int)PAGE_CACHE_SIZE); 90 memcpy(kmap(*++pagep), buf, l); 91 set_page_dirty(*pagep); 92 kunmap(*pagep); 93 } 94 } 95 96 void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data) 97 { 98 __be16 v = cpu_to_be16(data); 99 /* TODO: optimize later... */ 100 hfs_bnode_write(node, &v, off, 2); 101 } 102 103 void hfs_bnode_clear(struct hfs_bnode *node, int off, int len) 104 { 105 struct page **pagep; 106 int l; 107 108 off += node->page_offset; 109 pagep = node->page + (off >> PAGE_CACHE_SHIFT); 110 off &= ~PAGE_CACHE_MASK; 111 112 l = min(len, (int)PAGE_CACHE_SIZE - off); 113 memset(kmap(*pagep) + off, 0, l); 114 set_page_dirty(*pagep); 115 kunmap(*pagep); 116 117 while ((len -= l) != 0) { 118 l = min(len, (int)PAGE_CACHE_SIZE); 119 memset(kmap(*++pagep), 0, l); 120 set_page_dirty(*pagep); 121 kunmap(*pagep); 122 } 123 } 124 125 void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst, 126 struct hfs_bnode *src_node, int src, int len) 127 { 128 struct hfs_btree *tree; 129 struct page **src_page, **dst_page; 130 int l; 131 132 dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len); 133 if (!len) 134 return; 135 tree = src_node->tree; 136 src += src_node->page_offset; 137 dst += dst_node->page_offset; 138 src_page = src_node->page + (src >> PAGE_CACHE_SHIFT); 139 src &= ~PAGE_CACHE_MASK; 140 dst_page = dst_node->page + (dst >> PAGE_CACHE_SHIFT); 141 dst &= ~PAGE_CACHE_MASK; 142 143 if (src == dst) { 144 l = min(len, (int)PAGE_CACHE_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(len, (int)PAGE_CACHE_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_CACHE_SIZE - src < PAGE_CACHE_SIZE - dst) { 164 l = PAGE_CACHE_SIZE - src; 165 src = 0; 166 dst += l; 167 } else { 168 l = PAGE_CACHE_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 } 184 185 void 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 dprint(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_CACHE_SHIFT); 198 src = (src & ~PAGE_CACHE_MASK) + 1; 199 dst += len - 1; 200 dst_page = node->page + (dst >> PAGE_CACHE_SHIFT); 201 dst = (dst & ~PAGE_CACHE_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_CACHE_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_CACHE_SIZE; 229 dst -= l; 230 } else { 231 l = dst; 232 src -= l; 233 dst = PAGE_CACHE_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_CACHE_SIZE) 241 dst_page--; 242 else 243 src_page--; 244 } while ((len -= l)); 245 } 246 } else { 247 src_page = node->page + (src >> PAGE_CACHE_SHIFT); 248 src &= ~PAGE_CACHE_MASK; 249 dst_page = node->page + (dst >> PAGE_CACHE_SHIFT); 250 dst &= ~PAGE_CACHE_MASK; 251 252 if (src == dst) { 253 l = min(len, (int)PAGE_CACHE_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(len, (int)PAGE_CACHE_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_CACHE_SIZE - src < 275 PAGE_CACHE_SIZE - dst) { 276 l = PAGE_CACHE_SIZE - src; 277 src = 0; 278 dst += l; 279 } else { 280 l = PAGE_CACHE_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 } 297 298 void 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 dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this); 305 hfs_bnode_read(node, &desc, 0, sizeof(desc)); 306 dprint(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 dprint(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 tmp = hfs_bnode_read_u16(node, key_off) + 2; 319 else 320 tmp = node->tree->max_key_len + 2; 321 dprint(DBG_BNODE_MOD, " (%d", tmp); 322 hfs_bnode_read(node, &cnid, key_off + tmp, 4); 323 dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid)); 324 } else if (i && node->type == HFS_NODE_LEAF) { 325 int tmp; 326 327 tmp = hfs_bnode_read_u16(node, key_off); 328 dprint(DBG_BNODE_MOD, " (%d)", tmp); 329 } 330 } 331 dprint(DBG_BNODE_MOD, "\n"); 332 } 333 334 void hfs_bnode_unlink(struct hfs_bnode *node) 335 { 336 struct hfs_btree *tree; 337 struct hfs_bnode *tmp; 338 __be32 cnid; 339 340 tree = node->tree; 341 if (node->prev) { 342 tmp = hfs_bnode_find(tree, node->prev); 343 if (IS_ERR(tmp)) 344 return; 345 tmp->next = node->next; 346 cnid = cpu_to_be32(tmp->next); 347 hfs_bnode_write(tmp, &cnid, 348 offsetof(struct hfs_bnode_desc, next), 4); 349 hfs_bnode_put(tmp); 350 } else if (node->type == HFS_NODE_LEAF) 351 tree->leaf_head = node->next; 352 353 if (node->next) { 354 tmp = hfs_bnode_find(tree, node->next); 355 if (IS_ERR(tmp)) 356 return; 357 tmp->prev = node->prev; 358 cnid = cpu_to_be32(tmp->prev); 359 hfs_bnode_write(tmp, &cnid, 360 offsetof(struct hfs_bnode_desc, prev), 4); 361 hfs_bnode_put(tmp); 362 } else if (node->type == HFS_NODE_LEAF) 363 tree->leaf_tail = node->prev; 364 365 /* move down? */ 366 if (!node->prev && !node->next) 367 dprint(DBG_BNODE_MOD, "hfs_btree_del_level\n"); 368 if (!node->parent) { 369 tree->root = 0; 370 tree->depth = 0; 371 } 372 set_bit(HFS_BNODE_DELETED, &node->flags); 373 } 374 375 static inline int hfs_bnode_hash(u32 num) 376 { 377 num = (num >> 16) + num; 378 num += num >> 8; 379 return num & (NODE_HASH_SIZE - 1); 380 } 381 382 struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid) 383 { 384 struct hfs_bnode *node; 385 386 if (cnid >= tree->node_count) { 387 printk(KERN_ERR "hfs: request for non-existent node " 388 "%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 } 399 400 static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid) 401 { 402 struct super_block *sb; 403 struct hfs_bnode *node, *node2; 404 struct address_space *mapping; 405 struct page *page; 406 int size, block, i, hash; 407 loff_t off; 408 409 if (cnid >= tree->node_count) { 410 printk(KERN_ERR "hfs: request for non-existent node " 411 "%d in B*Tree\n", 412 cnid); 413 return NULL; 414 } 415 416 sb = tree->inode->i_sb; 417 size = sizeof(struct hfs_bnode) + tree->pages_per_bnode * 418 sizeof(struct page *); 419 node = kzalloc(size, GFP_KERNEL); 420 if (!node) 421 return NULL; 422 node->tree = tree; 423 node->this = cnid; 424 set_bit(HFS_BNODE_NEW, &node->flags); 425 atomic_set(&node->refcnt, 1); 426 dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n", 427 node->tree->cnid, node->this); 428 init_waitqueue_head(&node->lock_wq); 429 spin_lock(&tree->hash_lock); 430 node2 = hfs_bnode_findhash(tree, cnid); 431 if (!node2) { 432 hash = hfs_bnode_hash(cnid); 433 node->next_hash = tree->node_hash[hash]; 434 tree->node_hash[hash] = node; 435 tree->node_hash_cnt++; 436 } else { 437 spin_unlock(&tree->hash_lock); 438 kfree(node); 439 wait_event(node2->lock_wq, 440 !test_bit(HFS_BNODE_NEW, &node2->flags)); 441 return node2; 442 } 443 spin_unlock(&tree->hash_lock); 444 445 mapping = tree->inode->i_mapping; 446 off = (loff_t)cnid << tree->node_size_shift; 447 block = off >> PAGE_CACHE_SHIFT; 448 node->page_offset = off & ~PAGE_CACHE_MASK; 449 for (i = 0; i < tree->pages_per_bnode; block++, i++) { 450 page = read_mapping_page(mapping, block, NULL); 451 if (IS_ERR(page)) 452 goto fail; 453 if (PageError(page)) { 454 page_cache_release(page); 455 goto fail; 456 } 457 page_cache_release(page); 458 node->page[i] = page; 459 } 460 461 return node; 462 fail: 463 set_bit(HFS_BNODE_ERROR, &node->flags); 464 return node; 465 } 466 467 void hfs_bnode_unhash(struct hfs_bnode *node) 468 { 469 struct hfs_bnode **p; 470 471 dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n", 472 node->tree->cnid, node->this, atomic_read(&node->refcnt)); 473 for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)]; 474 *p && *p != node; p = &(*p)->next_hash) 475 ; 476 BUG_ON(!*p); 477 *p = node->next_hash; 478 node->tree->node_hash_cnt--; 479 } 480 481 /* Load a particular node out of a tree */ 482 struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num) 483 { 484 struct hfs_bnode *node; 485 struct hfs_bnode_desc *desc; 486 int i, rec_off, off, next_off; 487 int entry_size, key_size; 488 489 spin_lock(&tree->hash_lock); 490 node = hfs_bnode_findhash(tree, num); 491 if (node) { 492 hfs_bnode_get(node); 493 spin_unlock(&tree->hash_lock); 494 wait_event(node->lock_wq, 495 !test_bit(HFS_BNODE_NEW, &node->flags)); 496 if (test_bit(HFS_BNODE_ERROR, &node->flags)) 497 goto node_error; 498 return node; 499 } 500 spin_unlock(&tree->hash_lock); 501 node = __hfs_bnode_create(tree, num); 502 if (!node) 503 return ERR_PTR(-ENOMEM); 504 if (test_bit(HFS_BNODE_ERROR, &node->flags)) 505 goto node_error; 506 if (!test_bit(HFS_BNODE_NEW, &node->flags)) 507 return node; 508 509 desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + 510 node->page_offset); 511 node->prev = be32_to_cpu(desc->prev); 512 node->next = be32_to_cpu(desc->next); 513 node->num_recs = be16_to_cpu(desc->num_recs); 514 node->type = desc->type; 515 node->height = desc->height; 516 kunmap(node->page[0]); 517 518 switch (node->type) { 519 case HFS_NODE_HEADER: 520 case HFS_NODE_MAP: 521 if (node->height != 0) 522 goto node_error; 523 break; 524 case HFS_NODE_LEAF: 525 if (node->height != 1) 526 goto node_error; 527 break; 528 case HFS_NODE_INDEX: 529 if (node->height <= 1 || node->height > tree->depth) 530 goto node_error; 531 break; 532 default: 533 goto node_error; 534 } 535 536 rec_off = tree->node_size - 2; 537 off = hfs_bnode_read_u16(node, rec_off); 538 if (off != sizeof(struct hfs_bnode_desc)) 539 goto node_error; 540 for (i = 1; i <= node->num_recs; off = next_off, i++) { 541 rec_off -= 2; 542 next_off = hfs_bnode_read_u16(node, rec_off); 543 if (next_off <= off || 544 next_off > tree->node_size || 545 next_off & 1) 546 goto node_error; 547 entry_size = next_off - off; 548 if (node->type != HFS_NODE_INDEX && 549 node->type != HFS_NODE_LEAF) 550 continue; 551 key_size = hfs_bnode_read_u16(node, off) + 2; 552 if (key_size >= entry_size || key_size & 1) 553 goto node_error; 554 } 555 clear_bit(HFS_BNODE_NEW, &node->flags); 556 wake_up(&node->lock_wq); 557 return node; 558 559 node_error: 560 set_bit(HFS_BNODE_ERROR, &node->flags); 561 clear_bit(HFS_BNODE_NEW, &node->flags); 562 wake_up(&node->lock_wq); 563 hfs_bnode_put(node); 564 return ERR_PTR(-EIO); 565 } 566 567 void hfs_bnode_free(struct hfs_bnode *node) 568 { 569 #if 0 570 int i; 571 572 for (i = 0; i < node->tree->pages_per_bnode; i++) 573 if (node->page[i]) 574 page_cache_release(node->page[i]); 575 #endif 576 kfree(node); 577 } 578 579 struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num) 580 { 581 struct hfs_bnode *node; 582 struct page **pagep; 583 int i; 584 585 spin_lock(&tree->hash_lock); 586 node = hfs_bnode_findhash(tree, num); 587 spin_unlock(&tree->hash_lock); 588 if (node) { 589 printk(KERN_CRIT "new node %u already hashed?\n", num); 590 WARN_ON(1); 591 return node; 592 } 593 node = __hfs_bnode_create(tree, num); 594 if (!node) 595 return ERR_PTR(-ENOMEM); 596 if (test_bit(HFS_BNODE_ERROR, &node->flags)) { 597 hfs_bnode_put(node); 598 return ERR_PTR(-EIO); 599 } 600 601 pagep = node->page; 602 memset(kmap(*pagep) + node->page_offset, 0, 603 min((int)PAGE_CACHE_SIZE, (int)tree->node_size)); 604 set_page_dirty(*pagep); 605 kunmap(*pagep); 606 for (i = 1; i < tree->pages_per_bnode; i++) { 607 memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE); 608 set_page_dirty(*pagep); 609 kunmap(*pagep); 610 } 611 clear_bit(HFS_BNODE_NEW, &node->flags); 612 wake_up(&node->lock_wq); 613 614 return node; 615 } 616 617 void hfs_bnode_get(struct hfs_bnode *node) 618 { 619 if (node) { 620 atomic_inc(&node->refcnt); 621 dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n", 622 node->tree->cnid, node->this, 623 atomic_read(&node->refcnt)); 624 } 625 } 626 627 /* Dispose of resources used by a node */ 628 void hfs_bnode_put(struct hfs_bnode *node) 629 { 630 if (node) { 631 struct hfs_btree *tree = node->tree; 632 int i; 633 634 dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n", 635 node->tree->cnid, node->this, 636 atomic_read(&node->refcnt)); 637 BUG_ON(!atomic_read(&node->refcnt)); 638 if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock)) 639 return; 640 for (i = 0; i < tree->pages_per_bnode; i++) { 641 if (!node->page[i]) 642 continue; 643 mark_page_accessed(node->page[i]); 644 } 645 646 if (test_bit(HFS_BNODE_DELETED, &node->flags)) { 647 hfs_bnode_unhash(node); 648 spin_unlock(&tree->hash_lock); 649 hfs_bmap_free(node); 650 hfs_bnode_free(node); 651 return; 652 } 653 spin_unlock(&tree->hash_lock); 654 } 655 } 656 657