1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/hfsplus/brec.c 4 * 5 * Copyright (C) 2001 6 * Brad Boyer (flar@allandria.com) 7 * (C) 2003 Ardis Technologies <roman@ardistech.com> 8 * 9 * Handle individual btree records 10 */ 11 12 #include "hfsplus_fs.h" 13 #include "hfsplus_raw.h" 14 15 static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd); 16 static int hfs_brec_update_parent(struct hfs_find_data *fd); 17 static int hfs_btree_inc_height(struct hfs_btree *); 18 19 /* Get the length and offset of the given record in the given node */ 20 u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off) 21 { 22 __be16 retval[2]; 23 u16 dataoff; 24 25 dataoff = node->tree->node_size - (rec + 2) * 2; 26 hfs_bnode_read(node, retval, dataoff, 4); 27 *off = be16_to_cpu(retval[1]); 28 return be16_to_cpu(retval[0]) - *off; 29 } 30 31 /* Get the length of the key from a keyed record */ 32 u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec) 33 { 34 u16 retval, recoff; 35 36 if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF) 37 return 0; 38 39 if ((node->type == HFS_NODE_INDEX) && 40 !(node->tree->attributes & HFS_TREE_VARIDXKEYS) && 41 (node->tree->cnid != HFSPLUS_ATTR_CNID)) { 42 retval = node->tree->max_key_len + 2; 43 } else { 44 recoff = hfs_bnode_read_u16(node, 45 node->tree->node_size - (rec + 1) * 2); 46 if (!recoff) 47 return 0; 48 if (recoff > node->tree->node_size - 2) { 49 pr_err("recoff %d too large\n", recoff); 50 return 0; 51 } 52 53 retval = hfs_bnode_read_u16(node, recoff) + 2; 54 if (retval > node->tree->max_key_len + 2) { 55 pr_err("keylen %d too large\n", 56 retval); 57 retval = 0; 58 } 59 } 60 return retval; 61 } 62 63 int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len) 64 { 65 struct hfs_btree *tree; 66 struct hfs_bnode *node, *new_node; 67 int size, key_len, rec; 68 int data_off, end_off; 69 int idx_rec_off, data_rec_off, end_rec_off; 70 __be32 cnid; 71 72 tree = fd->tree; 73 if (!fd->bnode) { 74 if (!tree->root) 75 hfs_btree_inc_height(tree); 76 fd->bnode = hfs_bnode_find(tree, tree->leaf_head); 77 if (IS_ERR(fd->bnode)) 78 return PTR_ERR(fd->bnode); 79 fd->record = -1; 80 } 81 new_node = NULL; 82 key_len = be16_to_cpu(fd->search_key->key_len) + 2; 83 again: 84 /* new record idx and complete record size */ 85 rec = fd->record + 1; 86 size = key_len + entry_len; 87 88 node = fd->bnode; 89 hfs_bnode_dump(node); 90 /* get last offset */ 91 end_rec_off = tree->node_size - (node->num_recs + 1) * 2; 92 end_off = hfs_bnode_read_u16(node, end_rec_off); 93 end_rec_off -= 2; 94 hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", 95 rec, size, end_off, end_rec_off); 96 if (size > end_rec_off - end_off) { 97 if (new_node) 98 panic("not enough room!\n"); 99 new_node = hfs_bnode_split(fd); 100 if (IS_ERR(new_node)) 101 return PTR_ERR(new_node); 102 goto again; 103 } 104 if (node->type == HFS_NODE_LEAF) { 105 tree->leaf_count++; 106 mark_inode_dirty(tree->inode); 107 } 108 node->num_recs++; 109 /* write new last offset */ 110 hfs_bnode_write_u16(node, 111 offsetof(struct hfs_bnode_desc, num_recs), 112 node->num_recs); 113 hfs_bnode_write_u16(node, end_rec_off, end_off + size); 114 data_off = end_off; 115 data_rec_off = end_rec_off + 2; 116 idx_rec_off = tree->node_size - (rec + 1) * 2; 117 if (idx_rec_off == data_rec_off) 118 goto skip; 119 /* move all following entries */ 120 do { 121 data_off = hfs_bnode_read_u16(node, data_rec_off + 2); 122 hfs_bnode_write_u16(node, data_rec_off, data_off + size); 123 data_rec_off += 2; 124 } while (data_rec_off < idx_rec_off); 125 126 /* move data away */ 127 hfs_bnode_move(node, data_off + size, data_off, 128 end_off - data_off); 129 130 skip: 131 hfs_bnode_write(node, fd->search_key, data_off, key_len); 132 hfs_bnode_write(node, entry, data_off + key_len, entry_len); 133 hfs_bnode_dump(node); 134 135 /* 136 * update parent key if we inserted a key 137 * at the start of the node and it is not the new node 138 */ 139 if (!rec && new_node != node) { 140 hfs_bnode_read_key(node, fd->search_key, data_off + size); 141 hfs_brec_update_parent(fd); 142 } 143 144 if (new_node) { 145 hfs_bnode_put(fd->bnode); 146 if (!new_node->parent) { 147 hfs_btree_inc_height(tree); 148 new_node->parent = tree->root; 149 } 150 fd->bnode = hfs_bnode_find(tree, new_node->parent); 151 152 /* create index data entry */ 153 cnid = cpu_to_be32(new_node->this); 154 entry = &cnid; 155 entry_len = sizeof(cnid); 156 157 /* get index key */ 158 hfs_bnode_read_key(new_node, fd->search_key, 14); 159 __hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key); 160 161 hfs_bnode_put(new_node); 162 new_node = NULL; 163 164 if ((tree->attributes & HFS_TREE_VARIDXKEYS) || 165 (tree->cnid == HFSPLUS_ATTR_CNID)) 166 key_len = be16_to_cpu(fd->search_key->key_len) + 2; 167 else { 168 fd->search_key->key_len = 169 cpu_to_be16(tree->max_key_len); 170 key_len = tree->max_key_len + 2; 171 } 172 goto again; 173 } 174 175 return 0; 176 } 177 178 int hfs_brec_remove(struct hfs_find_data *fd) 179 { 180 struct hfs_btree *tree; 181 struct hfs_bnode *node, *parent; 182 int end_off, rec_off, data_off, size; 183 184 tree = fd->tree; 185 node = fd->bnode; 186 again: 187 rec_off = tree->node_size - (fd->record + 2) * 2; 188 end_off = tree->node_size - (node->num_recs + 1) * 2; 189 190 if (node->type == HFS_NODE_LEAF) { 191 tree->leaf_count--; 192 mark_inode_dirty(tree->inode); 193 } 194 hfs_bnode_dump(node); 195 hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n", 196 fd->record, fd->keylength + fd->entrylength); 197 if (!--node->num_recs) { 198 hfs_bnode_unlink(node); 199 if (!node->parent) 200 return 0; 201 parent = hfs_bnode_find(tree, node->parent); 202 if (IS_ERR(parent)) 203 return PTR_ERR(parent); 204 hfs_bnode_put(node); 205 node = fd->bnode = parent; 206 207 __hfs_brec_find(node, fd, hfs_find_rec_by_key); 208 goto again; 209 } 210 hfs_bnode_write_u16(node, 211 offsetof(struct hfs_bnode_desc, num_recs), 212 node->num_recs); 213 214 if (rec_off == end_off) 215 goto skip; 216 size = fd->keylength + fd->entrylength; 217 218 do { 219 data_off = hfs_bnode_read_u16(node, rec_off); 220 hfs_bnode_write_u16(node, rec_off + 2, data_off - size); 221 rec_off -= 2; 222 } while (rec_off >= end_off); 223 224 /* fill hole */ 225 hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size, 226 data_off - fd->keyoffset - size); 227 skip: 228 hfs_bnode_dump(node); 229 if (!fd->record) 230 hfs_brec_update_parent(fd); 231 return 0; 232 } 233 234 static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) 235 { 236 struct hfs_btree *tree; 237 struct hfs_bnode *node, *new_node, *next_node; 238 struct hfs_bnode_desc node_desc; 239 int num_recs, new_rec_off, new_off, old_rec_off; 240 int data_start, data_end, size; 241 242 tree = fd->tree; 243 node = fd->bnode; 244 new_node = hfs_bmap_alloc(tree); 245 if (IS_ERR(new_node)) 246 return new_node; 247 hfs_bnode_get(node); 248 hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n", 249 node->this, new_node->this, node->next); 250 new_node->next = node->next; 251 new_node->prev = node->this; 252 new_node->parent = node->parent; 253 new_node->type = node->type; 254 new_node->height = node->height; 255 256 if (node->next) 257 next_node = hfs_bnode_find(tree, node->next); 258 else 259 next_node = NULL; 260 261 if (IS_ERR(next_node)) { 262 hfs_bnode_put(node); 263 hfs_bnode_put(new_node); 264 return next_node; 265 } 266 267 size = tree->node_size / 2 - node->num_recs * 2 - 14; 268 old_rec_off = tree->node_size - 4; 269 num_recs = 1; 270 for (;;) { 271 data_start = hfs_bnode_read_u16(node, old_rec_off); 272 if (data_start > size) 273 break; 274 old_rec_off -= 2; 275 if (++num_recs < node->num_recs) 276 continue; 277 /* panic? */ 278 hfs_bnode_put(node); 279 hfs_bnode_put(new_node); 280 if (next_node) 281 hfs_bnode_put(next_node); 282 return ERR_PTR(-ENOSPC); 283 } 284 285 if (fd->record + 1 < num_recs) { 286 /* new record is in the lower half, 287 * so leave some more space there 288 */ 289 old_rec_off += 2; 290 num_recs--; 291 data_start = hfs_bnode_read_u16(node, old_rec_off); 292 } else { 293 hfs_bnode_put(node); 294 hfs_bnode_get(new_node); 295 fd->bnode = new_node; 296 fd->record -= num_recs; 297 fd->keyoffset -= data_start - 14; 298 fd->entryoffset -= data_start - 14; 299 } 300 new_node->num_recs = node->num_recs - num_recs; 301 node->num_recs = num_recs; 302 303 new_rec_off = tree->node_size - 2; 304 new_off = 14; 305 size = data_start - new_off; 306 num_recs = new_node->num_recs; 307 data_end = data_start; 308 while (num_recs) { 309 hfs_bnode_write_u16(new_node, new_rec_off, new_off); 310 old_rec_off -= 2; 311 new_rec_off -= 2; 312 data_end = hfs_bnode_read_u16(node, old_rec_off); 313 new_off = data_end - size; 314 num_recs--; 315 } 316 hfs_bnode_write_u16(new_node, new_rec_off, new_off); 317 hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start); 318 319 /* update new bnode header */ 320 node_desc.next = cpu_to_be32(new_node->next); 321 node_desc.prev = cpu_to_be32(new_node->prev); 322 node_desc.type = new_node->type; 323 node_desc.height = new_node->height; 324 node_desc.num_recs = cpu_to_be16(new_node->num_recs); 325 node_desc.reserved = 0; 326 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); 327 328 /* update previous bnode header */ 329 node->next = new_node->this; 330 hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc)); 331 node_desc.next = cpu_to_be32(node->next); 332 node_desc.num_recs = cpu_to_be16(node->num_recs); 333 hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc)); 334 335 /* update next bnode header */ 336 if (next_node) { 337 next_node->prev = new_node->this; 338 hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc)); 339 node_desc.prev = cpu_to_be32(next_node->prev); 340 hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc)); 341 hfs_bnode_put(next_node); 342 } else if (node->this == tree->leaf_tail) { 343 /* if there is no next node, this might be the new tail */ 344 tree->leaf_tail = new_node->this; 345 mark_inode_dirty(tree->inode); 346 } 347 348 hfs_bnode_dump(node); 349 hfs_bnode_dump(new_node); 350 hfs_bnode_put(node); 351 352 return new_node; 353 } 354 355 static int hfs_brec_update_parent(struct hfs_find_data *fd) 356 { 357 struct hfs_btree *tree; 358 struct hfs_bnode *node, *new_node, *parent; 359 int newkeylen, diff; 360 int rec, rec_off, end_rec_off; 361 int start_off, end_off; 362 363 tree = fd->tree; 364 node = fd->bnode; 365 new_node = NULL; 366 if (!node->parent) 367 return 0; 368 369 again: 370 parent = hfs_bnode_find(tree, node->parent); 371 if (IS_ERR(parent)) 372 return PTR_ERR(parent); 373 __hfs_brec_find(parent, fd, hfs_find_rec_by_key); 374 if (fd->record < 0) 375 return -ENOENT; 376 hfs_bnode_dump(parent); 377 rec = fd->record; 378 379 /* size difference between old and new key */ 380 if ((tree->attributes & HFS_TREE_VARIDXKEYS) || 381 (tree->cnid == HFSPLUS_ATTR_CNID)) 382 newkeylen = hfs_bnode_read_u16(node, 14) + 2; 383 else 384 fd->keylength = newkeylen = tree->max_key_len + 2; 385 hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n", 386 rec, fd->keylength, newkeylen); 387 388 rec_off = tree->node_size - (rec + 2) * 2; 389 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; 390 diff = newkeylen - fd->keylength; 391 if (!diff) 392 goto skip; 393 if (diff > 0) { 394 end_off = hfs_bnode_read_u16(parent, end_rec_off); 395 if (end_rec_off - end_off < diff) { 396 397 hfs_dbg(BNODE_MOD, "splitting index node\n"); 398 fd->bnode = parent; 399 new_node = hfs_bnode_split(fd); 400 if (IS_ERR(new_node)) 401 return PTR_ERR(new_node); 402 parent = fd->bnode; 403 rec = fd->record; 404 rec_off = tree->node_size - (rec + 2) * 2; 405 end_rec_off = tree->node_size - 406 (parent->num_recs + 1) * 2; 407 } 408 } 409 410 end_off = start_off = hfs_bnode_read_u16(parent, rec_off); 411 hfs_bnode_write_u16(parent, rec_off, start_off + diff); 412 start_off -= 4; /* move previous cnid too */ 413 414 while (rec_off > end_rec_off) { 415 rec_off -= 2; 416 end_off = hfs_bnode_read_u16(parent, rec_off); 417 hfs_bnode_write_u16(parent, rec_off, end_off + diff); 418 } 419 hfs_bnode_move(parent, start_off + diff, start_off, 420 end_off - start_off); 421 skip: 422 hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen); 423 hfs_bnode_dump(parent); 424 425 hfs_bnode_put(node); 426 node = parent; 427 428 if (new_node) { 429 __be32 cnid; 430 431 fd->bnode = hfs_bnode_find(tree, new_node->parent); 432 /* create index key and entry */ 433 hfs_bnode_read_key(new_node, fd->search_key, 14); 434 cnid = cpu_to_be32(new_node->this); 435 436 __hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key); 437 hfs_brec_insert(fd, &cnid, sizeof(cnid)); 438 hfs_bnode_put(fd->bnode); 439 hfs_bnode_put(new_node); 440 441 if (!rec) { 442 if (new_node == node) 443 goto out; 444 /* restore search_key */ 445 hfs_bnode_read_key(node, fd->search_key, 14); 446 } 447 } 448 449 if (!rec && node->parent) 450 goto again; 451 out: 452 fd->bnode = node; 453 return 0; 454 } 455 456 static int hfs_btree_inc_height(struct hfs_btree *tree) 457 { 458 struct hfs_bnode *node, *new_node; 459 struct hfs_bnode_desc node_desc; 460 int key_size, rec; 461 __be32 cnid; 462 463 node = NULL; 464 if (tree->root) { 465 node = hfs_bnode_find(tree, tree->root); 466 if (IS_ERR(node)) 467 return PTR_ERR(node); 468 } 469 new_node = hfs_bmap_alloc(tree); 470 if (IS_ERR(new_node)) { 471 hfs_bnode_put(node); 472 return PTR_ERR(new_node); 473 } 474 475 tree->root = new_node->this; 476 if (!tree->depth) { 477 tree->leaf_head = tree->leaf_tail = new_node->this; 478 new_node->type = HFS_NODE_LEAF; 479 new_node->num_recs = 0; 480 } else { 481 new_node->type = HFS_NODE_INDEX; 482 new_node->num_recs = 1; 483 } 484 new_node->parent = 0; 485 new_node->next = 0; 486 new_node->prev = 0; 487 new_node->height = ++tree->depth; 488 489 node_desc.next = cpu_to_be32(new_node->next); 490 node_desc.prev = cpu_to_be32(new_node->prev); 491 node_desc.type = new_node->type; 492 node_desc.height = new_node->height; 493 node_desc.num_recs = cpu_to_be16(new_node->num_recs); 494 node_desc.reserved = 0; 495 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); 496 497 rec = tree->node_size - 2; 498 hfs_bnode_write_u16(new_node, rec, 14); 499 500 if (node) { 501 /* insert old root idx into new root */ 502 node->parent = tree->root; 503 if (node->type == HFS_NODE_LEAF || 504 tree->attributes & HFS_TREE_VARIDXKEYS || 505 tree->cnid == HFSPLUS_ATTR_CNID) 506 key_size = hfs_bnode_read_u16(node, 14) + 2; 507 else 508 key_size = tree->max_key_len + 2; 509 hfs_bnode_copy(new_node, 14, node, 14, key_size); 510 511 if (!(tree->attributes & HFS_TREE_VARIDXKEYS) && 512 (tree->cnid != HFSPLUS_ATTR_CNID)) { 513 key_size = tree->max_key_len + 2; 514 hfs_bnode_write_u16(new_node, 14, tree->max_key_len); 515 } 516 cnid = cpu_to_be32(node->this); 517 hfs_bnode_write(new_node, &cnid, 14 + key_size, 4); 518 519 rec -= 2; 520 hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4); 521 522 hfs_bnode_put(node); 523 } 524 hfs_bnode_put(new_node); 525 mark_inode_dirty(tree->inode); 526 527 return 0; 528 } 529