1 /* 2 * linux/fs/hfsplus/btree.c 3 * 4 * Copyright (C) 2001 5 * Brad Boyer (flar@allandria.com) 6 * (C) 2003 Ardis Technologies <roman@ardistech.com> 7 * 8 * Handle opening/closing btree 9 */ 10 11 #include <linux/slab.h> 12 #include <linux/pagemap.h> 13 #include <linux/log2.h> 14 15 #include "hfsplus_fs.h" 16 #include "hfsplus_raw.h" 17 18 /* 19 * Initial source code of clump size calculation is gotten 20 * from http://opensource.apple.com/tarballs/diskdev_cmds/ 21 */ 22 #define CLUMP_ENTRIES 15 23 24 static short clumptbl[CLUMP_ENTRIES * 3] = { 25 /* 26 * Volume Attributes Catalog Extents 27 * Size Clump (MB) Clump (MB) Clump (MB) 28 */ 29 /* 1GB */ 4, 4, 4, 30 /* 2GB */ 6, 6, 4, 31 /* 4GB */ 8, 8, 4, 32 /* 8GB */ 11, 11, 5, 33 /* 34 * For volumes 16GB and larger, we want to make sure that a full OS 35 * install won't require fragmentation of the Catalog or Attributes 36 * B-trees. We do this by making the clump sizes sufficiently large, 37 * and by leaving a gap after the B-trees for them to grow into. 38 * 39 * For SnowLeopard 10A298, a FullNetInstall with all packages selected 40 * results in: 41 * Catalog B-tree Header 42 * nodeSize: 8192 43 * totalNodes: 31616 44 * freeNodes: 1978 45 * (used = 231.55 MB) 46 * Attributes B-tree Header 47 * nodeSize: 8192 48 * totalNodes: 63232 49 * freeNodes: 958 50 * (used = 486.52 MB) 51 * 52 * We also want Time Machine backup volumes to have a sufficiently 53 * large clump size to reduce fragmentation. 54 * 55 * The series of numbers for Catalog and Attribute form a geometric 56 * series. For Catalog (16GB to 512GB), each term is 8**(1/5) times 57 * the previous term. For Attributes (16GB to 512GB), each term is 58 * 4**(1/5) times the previous term. For 1TB to 16TB, each term is 59 * 2**(1/5) times the previous term. 60 */ 61 /* 16GB */ 64, 32, 5, 62 /* 32GB */ 84, 49, 6, 63 /* 64GB */ 111, 74, 7, 64 /* 128GB */ 147, 111, 8, 65 /* 256GB */ 194, 169, 9, 66 /* 512GB */ 256, 256, 11, 67 /* 1TB */ 294, 294, 14, 68 /* 2TB */ 338, 338, 16, 69 /* 4TB */ 388, 388, 20, 70 /* 8TB */ 446, 446, 25, 71 /* 16TB */ 512, 512, 32 72 }; 73 74 u32 hfsplus_calc_btree_clump_size(u32 block_size, u32 node_size, 75 u64 sectors, int file_id) 76 { 77 u32 mod = max(node_size, block_size); 78 u32 clump_size; 79 int column; 80 int i; 81 82 /* Figure out which column of the above table to use for this file. */ 83 switch (file_id) { 84 case HFSPLUS_ATTR_CNID: 85 column = 0; 86 break; 87 case HFSPLUS_CAT_CNID: 88 column = 1; 89 break; 90 default: 91 column = 2; 92 break; 93 } 94 95 /* 96 * The default clump size is 0.8% of the volume size. And 97 * it must also be a multiple of the node and block size. 98 */ 99 if (sectors < 0x200000) { 100 clump_size = sectors << 2; /* 0.8 % */ 101 if (clump_size < (8 * node_size)) 102 clump_size = 8 * node_size; 103 } else { 104 /* turn exponent into table index... */ 105 for (i = 0, sectors = sectors >> 22; 106 sectors && (i < CLUMP_ENTRIES - 1); 107 ++i, sectors = sectors >> 1) { 108 /* empty body */ 109 } 110 111 clump_size = clumptbl[column + (i) * 3] * 1024 * 1024; 112 } 113 114 /* 115 * Round the clump size to a multiple of node and block size. 116 * NOTE: This rounds down. 117 */ 118 clump_size /= mod; 119 clump_size *= mod; 120 121 /* 122 * Rounding down could have rounded down to 0 if the block size was 123 * greater than the clump size. If so, just use one block or node. 124 */ 125 if (clump_size == 0) 126 clump_size = mod; 127 128 return clump_size; 129 } 130 131 /* Get a reference to a B*Tree and do some initial checks */ 132 struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id) 133 { 134 struct hfs_btree *tree; 135 struct hfs_btree_header_rec *head; 136 struct address_space *mapping; 137 struct inode *inode; 138 struct page *page; 139 unsigned int size; 140 141 tree = kzalloc(sizeof(*tree), GFP_KERNEL); 142 if (!tree) 143 return NULL; 144 145 mutex_init(&tree->tree_lock); 146 spin_lock_init(&tree->hash_lock); 147 tree->sb = sb; 148 tree->cnid = id; 149 inode = hfsplus_iget(sb, id); 150 if (IS_ERR(inode)) 151 goto free_tree; 152 tree->inode = inode; 153 154 if (!HFSPLUS_I(tree->inode)->first_blocks) { 155 pr_err("invalid btree extent records (0 size)\n"); 156 goto free_inode; 157 } 158 159 mapping = tree->inode->i_mapping; 160 page = read_mapping_page(mapping, 0, NULL); 161 if (IS_ERR(page)) 162 goto free_inode; 163 164 /* Load the header */ 165 head = (struct hfs_btree_header_rec *)(kmap(page) + 166 sizeof(struct hfs_bnode_desc)); 167 tree->root = be32_to_cpu(head->root); 168 tree->leaf_count = be32_to_cpu(head->leaf_count); 169 tree->leaf_head = be32_to_cpu(head->leaf_head); 170 tree->leaf_tail = be32_to_cpu(head->leaf_tail); 171 tree->node_count = be32_to_cpu(head->node_count); 172 tree->free_nodes = be32_to_cpu(head->free_nodes); 173 tree->attributes = be32_to_cpu(head->attributes); 174 tree->node_size = be16_to_cpu(head->node_size); 175 tree->max_key_len = be16_to_cpu(head->max_key_len); 176 tree->depth = be16_to_cpu(head->depth); 177 178 /* Verify the tree and set the correct compare function */ 179 switch (id) { 180 case HFSPLUS_EXT_CNID: 181 if (tree->max_key_len != HFSPLUS_EXT_KEYLEN - sizeof(u16)) { 182 pr_err("invalid extent max_key_len %d\n", 183 tree->max_key_len); 184 goto fail_page; 185 } 186 if (tree->attributes & HFS_TREE_VARIDXKEYS) { 187 pr_err("invalid extent btree flag\n"); 188 goto fail_page; 189 } 190 191 tree->keycmp = hfsplus_ext_cmp_key; 192 break; 193 case HFSPLUS_CAT_CNID: 194 if (tree->max_key_len != HFSPLUS_CAT_KEYLEN - sizeof(u16)) { 195 pr_err("invalid catalog max_key_len %d\n", 196 tree->max_key_len); 197 goto fail_page; 198 } 199 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) { 200 pr_err("invalid catalog btree flag\n"); 201 goto fail_page; 202 } 203 204 if (test_bit(HFSPLUS_SB_HFSX, &HFSPLUS_SB(sb)->flags) && 205 (head->key_type == HFSPLUS_KEY_BINARY)) 206 tree->keycmp = hfsplus_cat_bin_cmp_key; 207 else { 208 tree->keycmp = hfsplus_cat_case_cmp_key; 209 set_bit(HFSPLUS_SB_CASEFOLD, &HFSPLUS_SB(sb)->flags); 210 } 211 break; 212 case HFSPLUS_ATTR_CNID: 213 if (tree->max_key_len != HFSPLUS_ATTR_KEYLEN - sizeof(u16)) { 214 pr_err("invalid attributes max_key_len %d\n", 215 tree->max_key_len); 216 goto fail_page; 217 } 218 tree->keycmp = hfsplus_attr_bin_cmp_key; 219 break; 220 default: 221 pr_err("unknown B*Tree requested\n"); 222 goto fail_page; 223 } 224 225 if (!(tree->attributes & HFS_TREE_BIGKEYS)) { 226 pr_err("invalid btree flag\n"); 227 goto fail_page; 228 } 229 230 size = tree->node_size; 231 if (!is_power_of_2(size)) 232 goto fail_page; 233 if (!tree->node_count) 234 goto fail_page; 235 236 tree->node_size_shift = ffs(size) - 1; 237 238 tree->pages_per_bnode = 239 (tree->node_size + PAGE_SIZE - 1) >> 240 PAGE_SHIFT; 241 242 kunmap(page); 243 put_page(page); 244 return tree; 245 246 fail_page: 247 put_page(page); 248 free_inode: 249 tree->inode->i_mapping->a_ops = &hfsplus_aops; 250 iput(tree->inode); 251 free_tree: 252 kfree(tree); 253 return NULL; 254 } 255 256 /* Release resources used by a btree */ 257 void hfs_btree_close(struct hfs_btree *tree) 258 { 259 struct hfs_bnode *node; 260 int i; 261 262 if (!tree) 263 return; 264 265 for (i = 0; i < NODE_HASH_SIZE; i++) { 266 while ((node = tree->node_hash[i])) { 267 tree->node_hash[i] = node->next_hash; 268 if (atomic_read(&node->refcnt)) 269 pr_crit("node %d:%d " 270 "still has %d user(s)!\n", 271 node->tree->cnid, node->this, 272 atomic_read(&node->refcnt)); 273 hfs_bnode_free(node); 274 tree->node_hash_cnt--; 275 } 276 } 277 iput(tree->inode); 278 kfree(tree); 279 } 280 281 int hfs_btree_write(struct hfs_btree *tree) 282 { 283 struct hfs_btree_header_rec *head; 284 struct hfs_bnode *node; 285 struct page *page; 286 287 node = hfs_bnode_find(tree, 0); 288 if (IS_ERR(node)) 289 /* panic? */ 290 return -EIO; 291 /* Load the header */ 292 page = node->page[0]; 293 head = (struct hfs_btree_header_rec *)(kmap(page) + 294 sizeof(struct hfs_bnode_desc)); 295 296 head->root = cpu_to_be32(tree->root); 297 head->leaf_count = cpu_to_be32(tree->leaf_count); 298 head->leaf_head = cpu_to_be32(tree->leaf_head); 299 head->leaf_tail = cpu_to_be32(tree->leaf_tail); 300 head->node_count = cpu_to_be32(tree->node_count); 301 head->free_nodes = cpu_to_be32(tree->free_nodes); 302 head->attributes = cpu_to_be32(tree->attributes); 303 head->depth = cpu_to_be16(tree->depth); 304 305 kunmap(page); 306 set_page_dirty(page); 307 hfs_bnode_put(node); 308 return 0; 309 } 310 311 static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx) 312 { 313 struct hfs_btree *tree = prev->tree; 314 struct hfs_bnode *node; 315 struct hfs_bnode_desc desc; 316 __be32 cnid; 317 318 node = hfs_bnode_create(tree, idx); 319 if (IS_ERR(node)) 320 return node; 321 322 tree->free_nodes--; 323 prev->next = idx; 324 cnid = cpu_to_be32(idx); 325 hfs_bnode_write(prev, &cnid, offsetof(struct hfs_bnode_desc, next), 4); 326 327 node->type = HFS_NODE_MAP; 328 node->num_recs = 1; 329 hfs_bnode_clear(node, 0, tree->node_size); 330 desc.next = 0; 331 desc.prev = 0; 332 desc.type = HFS_NODE_MAP; 333 desc.height = 0; 334 desc.num_recs = cpu_to_be16(1); 335 desc.reserved = 0; 336 hfs_bnode_write(node, &desc, 0, sizeof(desc)); 337 hfs_bnode_write_u16(node, 14, 0x8000); 338 hfs_bnode_write_u16(node, tree->node_size - 2, 14); 339 hfs_bnode_write_u16(node, tree->node_size - 4, tree->node_size - 6); 340 341 return node; 342 } 343 344 struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree) 345 { 346 struct hfs_bnode *node, *next_node; 347 struct page **pagep; 348 u32 nidx, idx; 349 unsigned off; 350 u16 off16; 351 u16 len; 352 u8 *data, byte, m; 353 int i; 354 355 while (!tree->free_nodes) { 356 struct inode *inode = tree->inode; 357 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 358 u32 count; 359 int res; 360 361 res = hfsplus_file_extend(inode, hfs_bnode_need_zeroout(tree)); 362 if (res) 363 return ERR_PTR(res); 364 hip->phys_size = inode->i_size = 365 (loff_t)hip->alloc_blocks << 366 HFSPLUS_SB(tree->sb)->alloc_blksz_shift; 367 hip->fs_blocks = 368 hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift; 369 inode_set_bytes(inode, inode->i_size); 370 count = inode->i_size >> tree->node_size_shift; 371 tree->free_nodes = count - tree->node_count; 372 tree->node_count = count; 373 } 374 375 nidx = 0; 376 node = hfs_bnode_find(tree, nidx); 377 if (IS_ERR(node)) 378 return node; 379 len = hfs_brec_lenoff(node, 2, &off16); 380 off = off16; 381 382 off += node->page_offset; 383 pagep = node->page + (off >> PAGE_SHIFT); 384 data = kmap(*pagep); 385 off &= ~PAGE_MASK; 386 idx = 0; 387 388 for (;;) { 389 while (len) { 390 byte = data[off]; 391 if (byte != 0xff) { 392 for (m = 0x80, i = 0; i < 8; m >>= 1, i++) { 393 if (!(byte & m)) { 394 idx += i; 395 data[off] |= m; 396 set_page_dirty(*pagep); 397 kunmap(*pagep); 398 tree->free_nodes--; 399 mark_inode_dirty(tree->inode); 400 hfs_bnode_put(node); 401 return hfs_bnode_create(tree, 402 idx); 403 } 404 } 405 } 406 if (++off >= PAGE_SIZE) { 407 kunmap(*pagep); 408 data = kmap(*++pagep); 409 off = 0; 410 } 411 idx += 8; 412 len--; 413 } 414 kunmap(*pagep); 415 nidx = node->next; 416 if (!nidx) { 417 hfs_dbg(BNODE_MOD, "create new bmap node\n"); 418 next_node = hfs_bmap_new_bmap(node, idx); 419 } else 420 next_node = hfs_bnode_find(tree, nidx); 421 hfs_bnode_put(node); 422 if (IS_ERR(next_node)) 423 return next_node; 424 node = next_node; 425 426 len = hfs_brec_lenoff(node, 0, &off16); 427 off = off16; 428 off += node->page_offset; 429 pagep = node->page + (off >> PAGE_SHIFT); 430 data = kmap(*pagep); 431 off &= ~PAGE_MASK; 432 } 433 } 434 435 void hfs_bmap_free(struct hfs_bnode *node) 436 { 437 struct hfs_btree *tree; 438 struct page *page; 439 u16 off, len; 440 u32 nidx; 441 u8 *data, byte, m; 442 443 hfs_dbg(BNODE_MOD, "btree_free_node: %u\n", node->this); 444 BUG_ON(!node->this); 445 tree = node->tree; 446 nidx = node->this; 447 node = hfs_bnode_find(tree, 0); 448 if (IS_ERR(node)) 449 return; 450 len = hfs_brec_lenoff(node, 2, &off); 451 while (nidx >= len * 8) { 452 u32 i; 453 454 nidx -= len * 8; 455 i = node->next; 456 hfs_bnode_put(node); 457 if (!i) { 458 /* panic */; 459 pr_crit("unable to free bnode %u. " 460 "bmap not found!\n", 461 node->this); 462 return; 463 } 464 node = hfs_bnode_find(tree, i); 465 if (IS_ERR(node)) 466 return; 467 if (node->type != HFS_NODE_MAP) { 468 /* panic */; 469 pr_crit("invalid bmap found! " 470 "(%u,%d)\n", 471 node->this, node->type); 472 hfs_bnode_put(node); 473 return; 474 } 475 len = hfs_brec_lenoff(node, 0, &off); 476 } 477 off += node->page_offset + nidx / 8; 478 page = node->page[off >> PAGE_SHIFT]; 479 data = kmap(page); 480 off &= ~PAGE_MASK; 481 m = 1 << (~nidx & 7); 482 byte = data[off]; 483 if (!(byte & m)) { 484 pr_crit("trying to free free bnode " 485 "%u(%d)\n", 486 node->this, node->type); 487 kunmap(page); 488 hfs_bnode_put(node); 489 return; 490 } 491 data[off] = byte & ~m; 492 set_page_dirty(page); 493 kunmap(page); 494 hfs_bnode_put(node); 495 tree->free_nodes++; 496 mark_inode_dirty(tree->inode); 497 } 498