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