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