Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 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_CACHE_SIZE - 1) >> |
| 240 | PAGE_CACHE_SHIFT; |
| 241 | |
| 242 | kunmap(page); |
| 243 | page_cache_release(page); |
| 244 | return tree; |
| 245 | |
| 246 | fail_page: |
| 247 | page_cache_release(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_CACHE_SHIFT); |
| 384 | data = kmap(*pagep); |
| 385 | off &= ~PAGE_CACHE_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_CACHE_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_CACHE_SHIFT); |
| 430 | data = kmap(*pagep); |
| 431 | off &= ~PAGE_CACHE_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_CACHE_SHIFT]; |
| 479 | data = kmap(page); |
| 480 | off &= ~PAGE_CACHE_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 | } |