1 /* 2 * linux/fs/hfsplus/brec.c 3 * 4 * Copyright (C) 2001 5 * Brad Boyer (flar@allandria.com) 6 * (C) 2003 Ardis Technologies <roman@ardistech.com> 7 * 8 * Handle individual btree records 9 */ 10 11 #include "hfsplus_fs.h" 12 #include "hfsplus_raw.h" 13 14 static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd); 15 static int hfs_brec_update_parent(struct hfs_find_data *fd); 16 static int hfs_btree_inc_height(struct hfs_btree *); 17 18 /* Get the length and offset of the given record in the given node */ 19 u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off) 20 { 21 __be16 retval[2]; 22 u16 dataoff; 23 24 dataoff = node->tree->node_size - (rec + 2) * 2; 25 hfs_bnode_read(node, retval, dataoff, 4); 26 *off = be16_to_cpu(retval[1]); 27 return be16_to_cpu(retval[0]) - *off; 28 } 29 30 /* Get the length of the key from a keyed record */ 31 u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec) 32 { 33 u16 retval, recoff; 34 35 if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF) 36 return 0; 37 38 if ((node->type == HFS_NODE_INDEX) && 39 !(node->tree->attributes & HFS_TREE_VARIDXKEYS) && 40 (node->tree->cnid != HFSPLUS_ATTR_CNID)) { 41 retval = node->tree->max_key_len + 2; 42 } else { 43 recoff = hfs_bnode_read_u16(node, 44 node->tree->node_size - (rec + 1) * 2); 45 if (!recoff) 46 return 0; 47 if (recoff > node->tree->node_size - 2) { 48 pr_err("recoff %d too large\n", recoff); 49 return 0; 50 } 51 52 retval = hfs_bnode_read_u16(node, recoff) + 2; 53 if (retval > node->tree->max_key_len + 2) { 54 pr_err("keylen %d too large\n", 55 retval); 56 retval = 0; 57 } 58 } 59 return retval; 60 } 61 62 int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len) 63 { 64 struct hfs_btree *tree; 65 struct hfs_bnode *node, *new_node; 66 int size, key_len, rec; 67 int data_off, end_off; 68 int idx_rec_off, data_rec_off, end_rec_off; 69 __be32 cnid; 70 71 tree = fd->tree; 72 if (!fd->bnode) { 73 if (!tree->root) 74 hfs_btree_inc_height(tree); 75 fd->bnode = hfs_bnode_find(tree, tree->leaf_head); 76 if (IS_ERR(fd->bnode)) 77 return PTR_ERR(fd->bnode); 78 fd->record = -1; 79 } 80 new_node = NULL; 81 key_len = be16_to_cpu(fd->search_key->key_len) + 2; 82 again: 83 /* new record idx and complete record size */ 84 rec = fd->record + 1; 85 size = key_len + entry_len; 86 87 node = fd->bnode; 88 hfs_bnode_dump(node); 89 /* get last offset */ 90 end_rec_off = tree->node_size - (node->num_recs + 1) * 2; 91 end_off = hfs_bnode_read_u16(node, end_rec_off); 92 end_rec_off -= 2; 93 hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", 94 rec, size, end_off, end_rec_off); 95 if (size > end_rec_off - end_off) { 96 if (new_node) 97 panic("not enough room!\n"); 98 new_node = hfs_bnode_split(fd); 99 if (IS_ERR(new_node)) 100 return PTR_ERR(new_node); 101 goto again; 102 } 103 if (node->type == HFS_NODE_LEAF) { 104 tree->leaf_count++; 105 mark_inode_dirty(tree->inode); 106 } 107 node->num_recs++; 108 /* write new last offset */ 109 hfs_bnode_write_u16(node, 110 offsetof(struct hfs_bnode_desc, num_recs), 111 node->num_recs); 112 hfs_bnode_write_u16(node, end_rec_off, end_off + size); 113 data_off = end_off; 114 data_rec_off = end_rec_off + 2; 115 idx_rec_off = tree->node_size - (rec + 1) * 2; 116 if (idx_rec_off == data_rec_off) 117 goto skip; 118 /* move all following entries */ 119 do { 120 data_off = hfs_bnode_read_u16(node, data_rec_off + 2); 121 hfs_bnode_write_u16(node, data_rec_off, data_off + size); 122 data_rec_off += 2; 123 } while (data_rec_off < idx_rec_off); 124 125 /* move data away */ 126 hfs_bnode_move(node, data_off + size, data_off, 127 end_off - data_off); 128 129 skip: 130 hfs_bnode_write(node, fd->search_key, data_off, key_len); 131 hfs_bnode_write(node, entry, data_off + key_len, entry_len); 132 hfs_bnode_dump(node); 133 134 /* 135 * update parent key if we inserted a key 136 * at the start of the node and it is not the new node 137 */ 138 if (!rec && new_node != node) { 139 hfs_bnode_read_key(node, fd->search_key, data_off + size); 140 hfs_brec_update_parent(fd); 141 } 142 143 if (new_node) { 144 hfs_bnode_put(fd->bnode); 145 if (!new_node->parent) { 146 hfs_btree_inc_height(tree); 147 new_node->parent = tree->root; 148 } 149 fd->bnode = hfs_bnode_find(tree, new_node->parent); 150 151 /* create index data entry */ 152 cnid = cpu_to_be32(new_node->this); 153 entry = &cnid; 154 entry_len = sizeof(cnid); 155 156 /* get index key */ 157 hfs_bnode_read_key(new_node, fd->search_key, 14); 158 __hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key); 159 160 hfs_bnode_put(new_node); 161 new_node = NULL; 162 163 if ((tree->attributes & HFS_TREE_VARIDXKEYS) || 164 (tree->cnid == HFSPLUS_ATTR_CNID)) 165 key_len = be16_to_cpu(fd->search_key->key_len) + 2; 166 else { 167 fd->search_key->key_len = 168 cpu_to_be16(tree->max_key_len); 169 key_len = tree->max_key_len + 2; 170 } 171 goto again; 172 } 173 174 return 0; 175 } 176 177 int hfs_brec_remove(struct hfs_find_data *fd) 178 { 179 struct hfs_btree *tree; 180 struct hfs_bnode *node, *parent; 181 int end_off, rec_off, data_off, size; 182 183 tree = fd->tree; 184 node = fd->bnode; 185 again: 186 rec_off = tree->node_size - (fd->record + 2) * 2; 187 end_off = tree->node_size - (node->num_recs + 1) * 2; 188 189 if (node->type == HFS_NODE_LEAF) { 190 tree->leaf_count--; 191 mark_inode_dirty(tree->inode); 192 } 193 hfs_bnode_dump(node); 194 hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n", 195 fd->record, fd->keylength + fd->entrylength); 196 if (!--node->num_recs) { 197 hfs_bnode_unlink(node); 198 if (!node->parent) 199 return 0; 200 parent = hfs_bnode_find(tree, node->parent); 201 if (IS_ERR(parent)) 202 return PTR_ERR(parent); 203 hfs_bnode_put(node); 204 node = fd->bnode = parent; 205 206 __hfs_brec_find(node, fd, hfs_find_rec_by_key); 207 goto again; 208 } 209 hfs_bnode_write_u16(node, 210 offsetof(struct hfs_bnode_desc, num_recs), 211 node->num_recs); 212 213 if (rec_off == end_off) 214 goto skip; 215 size = fd->keylength + fd->entrylength; 216 217 do { 218 data_off = hfs_bnode_read_u16(node, rec_off); 219 hfs_bnode_write_u16(node, rec_off + 2, data_off - size); 220 rec_off -= 2; 221 } while (rec_off >= end_off); 222 223 /* fill hole */ 224 hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size, 225 data_off - fd->keyoffset - size); 226 skip: 227 hfs_bnode_dump(node); 228 if (!fd->record) 229 hfs_brec_update_parent(fd); 230 return 0; 231 } 232 233 static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) 234 { 235 struct hfs_btree *tree; 236 struct hfs_bnode *node, *new_node, *next_node; 237 struct hfs_bnode_desc node_desc; 238 int num_recs, new_rec_off, new_off, old_rec_off; 239 int data_start, data_end, size; 240 241 tree = fd->tree; 242 node = fd->bnode; 243 new_node = hfs_bmap_alloc(tree); 244 if (IS_ERR(new_node)) 245 return new_node; 246 hfs_bnode_get(node); 247 hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n", 248 node->this, new_node->this, node->next); 249 new_node->next = node->next; 250 new_node->prev = node->this; 251 new_node->parent = node->parent; 252 new_node->type = node->type; 253 new_node->height = node->height; 254 255 if (node->next) 256 next_node = hfs_bnode_find(tree, node->next); 257 else 258 next_node = NULL; 259 260 if (IS_ERR(next_node)) { 261 hfs_bnode_put(node); 262 hfs_bnode_put(new_node); 263 return next_node; 264 } 265 266 size = tree->node_size / 2 - node->num_recs * 2 - 14; 267 old_rec_off = tree->node_size - 4; 268 num_recs = 1; 269 for (;;) { 270 data_start = hfs_bnode_read_u16(node, old_rec_off); 271 if (data_start > size) 272 break; 273 old_rec_off -= 2; 274 if (++num_recs < node->num_recs) 275 continue; 276 /* panic? */ 277 hfs_bnode_put(node); 278 hfs_bnode_put(new_node); 279 if (next_node) 280 hfs_bnode_put(next_node); 281 return ERR_PTR(-ENOSPC); 282 } 283 284 if (fd->record + 1 < num_recs) { 285 /* new record is in the lower half, 286 * so leave some more space there 287 */ 288 old_rec_off += 2; 289 num_recs--; 290 data_start = hfs_bnode_read_u16(node, old_rec_off); 291 } else { 292 hfs_bnode_put(node); 293 hfs_bnode_get(new_node); 294 fd->bnode = new_node; 295 fd->record -= num_recs; 296 fd->keyoffset -= data_start - 14; 297 fd->entryoffset -= data_start - 14; 298 } 299 new_node->num_recs = node->num_recs - num_recs; 300 node->num_recs = num_recs; 301 302 new_rec_off = tree->node_size - 2; 303 new_off = 14; 304 size = data_start - new_off; 305 num_recs = new_node->num_recs; 306 data_end = data_start; 307 while (num_recs) { 308 hfs_bnode_write_u16(new_node, new_rec_off, new_off); 309 old_rec_off -= 2; 310 new_rec_off -= 2; 311 data_end = hfs_bnode_read_u16(node, old_rec_off); 312 new_off = data_end - size; 313 num_recs--; 314 } 315 hfs_bnode_write_u16(new_node, new_rec_off, new_off); 316 hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start); 317 318 /* update new bnode header */ 319 node_desc.next = cpu_to_be32(new_node->next); 320 node_desc.prev = cpu_to_be32(new_node->prev); 321 node_desc.type = new_node->type; 322 node_desc.height = new_node->height; 323 node_desc.num_recs = cpu_to_be16(new_node->num_recs); 324 node_desc.reserved = 0; 325 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); 326 327 /* update previous bnode header */ 328 node->next = new_node->this; 329 hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc)); 330 node_desc.next = cpu_to_be32(node->next); 331 node_desc.num_recs = cpu_to_be16(node->num_recs); 332 hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc)); 333 334 /* update next bnode header */ 335 if (next_node) { 336 next_node->prev = new_node->this; 337 hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc)); 338 node_desc.prev = cpu_to_be32(next_node->prev); 339 hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc)); 340 hfs_bnode_put(next_node); 341 } else if (node->this == tree->leaf_tail) { 342 /* if there is no next node, this might be the new tail */ 343 tree->leaf_tail = new_node->this; 344 mark_inode_dirty(tree->inode); 345 } 346 347 hfs_bnode_dump(node); 348 hfs_bnode_dump(new_node); 349 hfs_bnode_put(node); 350 351 return new_node; 352 } 353 354 static int hfs_brec_update_parent(struct hfs_find_data *fd) 355 { 356 struct hfs_btree *tree; 357 struct hfs_bnode *node, *new_node, *parent; 358 int newkeylen, diff; 359 int rec, rec_off, end_rec_off; 360 int start_off, end_off; 361 362 tree = fd->tree; 363 node = fd->bnode; 364 new_node = NULL; 365 if (!node->parent) 366 return 0; 367 368 again: 369 parent = hfs_bnode_find(tree, node->parent); 370 if (IS_ERR(parent)) 371 return PTR_ERR(parent); 372 __hfs_brec_find(parent, fd, hfs_find_rec_by_key); 373 if (fd->record < 0) 374 return -ENOENT; 375 hfs_bnode_dump(parent); 376 rec = fd->record; 377 378 /* size difference between old and new key */ 379 if ((tree->attributes & HFS_TREE_VARIDXKEYS) || 380 (tree->cnid == HFSPLUS_ATTR_CNID)) 381 newkeylen = hfs_bnode_read_u16(node, 14) + 2; 382 else 383 fd->keylength = newkeylen = tree->max_key_len + 2; 384 hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n", 385 rec, fd->keylength, newkeylen); 386 387 rec_off = tree->node_size - (rec + 2) * 2; 388 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; 389 diff = newkeylen - fd->keylength; 390 if (!diff) 391 goto skip; 392 if (diff > 0) { 393 end_off = hfs_bnode_read_u16(parent, end_rec_off); 394 if (end_rec_off - end_off < diff) { 395 396 hfs_dbg(BNODE_MOD, "splitting index node\n"); 397 fd->bnode = parent; 398 new_node = hfs_bnode_split(fd); 399 if (IS_ERR(new_node)) 400 return PTR_ERR(new_node); 401 parent = fd->bnode; 402 rec = fd->record; 403 rec_off = tree->node_size - (rec + 2) * 2; 404 end_rec_off = tree->node_size - 405 (parent->num_recs + 1) * 2; 406 } 407 } 408 409 end_off = start_off = hfs_bnode_read_u16(parent, rec_off); 410 hfs_bnode_write_u16(parent, rec_off, start_off + diff); 411 start_off -= 4; /* move previous cnid too */ 412 413 while (rec_off > end_rec_off) { 414 rec_off -= 2; 415 end_off = hfs_bnode_read_u16(parent, rec_off); 416 hfs_bnode_write_u16(parent, rec_off, end_off + diff); 417 } 418 hfs_bnode_move(parent, start_off + diff, start_off, 419 end_off - start_off); 420 skip: 421 hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen); 422 hfs_bnode_dump(parent); 423 424 hfs_bnode_put(node); 425 node = parent; 426 427 if (new_node) { 428 __be32 cnid; 429 430 fd->bnode = hfs_bnode_find(tree, new_node->parent); 431 /* create index key and entry */ 432 hfs_bnode_read_key(new_node, fd->search_key, 14); 433 cnid = cpu_to_be32(new_node->this); 434 435 __hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key); 436 hfs_brec_insert(fd, &cnid, sizeof(cnid)); 437 hfs_bnode_put(fd->bnode); 438 hfs_bnode_put(new_node); 439 440 if (!rec) { 441 if (new_node == node) 442 goto out; 443 /* restore search_key */ 444 hfs_bnode_read_key(node, fd->search_key, 14); 445 } 446 } 447 448 if (!rec && node->parent) 449 goto again; 450 out: 451 fd->bnode = node; 452 return 0; 453 } 454 455 static int hfs_btree_inc_height(struct hfs_btree *tree) 456 { 457 struct hfs_bnode *node, *new_node; 458 struct hfs_bnode_desc node_desc; 459 int key_size, rec; 460 __be32 cnid; 461 462 node = NULL; 463 if (tree->root) { 464 node = hfs_bnode_find(tree, tree->root); 465 if (IS_ERR(node)) 466 return PTR_ERR(node); 467 } 468 new_node = hfs_bmap_alloc(tree); 469 if (IS_ERR(new_node)) { 470 hfs_bnode_put(node); 471 return PTR_ERR(new_node); 472 } 473 474 tree->root = new_node->this; 475 if (!tree->depth) { 476 tree->leaf_head = tree->leaf_tail = new_node->this; 477 new_node->type = HFS_NODE_LEAF; 478 new_node->num_recs = 0; 479 } else { 480 new_node->type = HFS_NODE_INDEX; 481 new_node->num_recs = 1; 482 } 483 new_node->parent = 0; 484 new_node->next = 0; 485 new_node->prev = 0; 486 new_node->height = ++tree->depth; 487 488 node_desc.next = cpu_to_be32(new_node->next); 489 node_desc.prev = cpu_to_be32(new_node->prev); 490 node_desc.type = new_node->type; 491 node_desc.height = new_node->height; 492 node_desc.num_recs = cpu_to_be16(new_node->num_recs); 493 node_desc.reserved = 0; 494 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); 495 496 rec = tree->node_size - 2; 497 hfs_bnode_write_u16(new_node, rec, 14); 498 499 if (node) { 500 /* insert old root idx into new root */ 501 node->parent = tree->root; 502 if (node->type == HFS_NODE_LEAF || 503 tree->attributes & HFS_TREE_VARIDXKEYS || 504 tree->cnid == HFSPLUS_ATTR_CNID) 505 key_size = hfs_bnode_read_u16(node, 14) + 2; 506 else 507 key_size = tree->max_key_len + 2; 508 hfs_bnode_copy(new_node, 14, node, 14, key_size); 509 510 if (!(tree->attributes & HFS_TREE_VARIDXKEYS) && 511 (tree->cnid != HFSPLUS_ATTR_CNID)) { 512 key_size = tree->max_key_len + 2; 513 hfs_bnode_write_u16(new_node, 14, tree->max_key_len); 514 } 515 cnid = cpu_to_be32(node->this); 516 hfs_bnode_write(new_node, &cnid, 14 + key_size, 4); 517 518 rec -= 2; 519 hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4); 520 521 hfs_bnode_put(node); 522 } 523 hfs_bnode_put(new_node); 524 mark_inode_dirty(tree->inode); 525 526 return 0; 527 } 528