1/* 2 * linux/fs/hfs/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 "btree.h" 12 13static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd); 14static int hfs_brec_update_parent(struct hfs_find_data *fd); 15static int hfs_btree_inc_height(struct hfs_btree *tree); 16 17/* Get the length and offset of the given record in the given node */ 18u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off) 19{ 20 __be16 retval[2]; 21 u16 dataoff; 22 23 dataoff = node->tree->node_size - (rec + 2) * 2; 24 hfs_bnode_read(node, retval, dataoff, 4); 25 *off = be16_to_cpu(retval[1]); 26 return be16_to_cpu(retval[0]) - *off; 27} 28 29/* Get the length of the key from a keyed record */ 30u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec) 31{ 32 u16 retval, recoff; 33 34 if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF) 35 return 0; 36 37 if ((node->type == HFS_NODE_INDEX) && 38 !(node->tree->attributes & HFS_TREE_VARIDXKEYS)) { 39 if (node->tree->attributes & HFS_TREE_BIGKEYS) 40 retval = node->tree->max_key_len + 2; 41 else 42 retval = node->tree->max_key_len + 1; 43 } else { 44 recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2); 45 if (!recoff) 46 return 0; 47 if (node->tree->attributes & HFS_TREE_BIGKEYS) { 48 retval = hfs_bnode_read_u16(node, recoff) + 2; 49 if (retval > node->tree->max_key_len + 2) { 50 printk(KERN_ERR "hfs: keylen %d too large\n", 51 retval); 52 retval = 0; 53 } 54 } else { 55 retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1; 56 if (retval > node->tree->max_key_len + 1) { 57 printk(KERN_ERR "hfs: keylen %d too large\n", 58 retval); 59 retval = 0; 60 } 61 } 62 } 63 return retval; 64} 65 66int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len) 67{ 68 struct hfs_btree *tree; 69 struct hfs_bnode *node, *new_node; 70 int size, key_len, rec; 71 int data_off, end_off; 72 int idx_rec_off, data_rec_off, end_rec_off; 73 __be32 cnid; 74 75 tree = fd->tree; 76 if (!fd->bnode) { 77 if (!tree->root) 78 hfs_btree_inc_height(tree); 79 fd->bnode = hfs_bnode_find(tree, tree->leaf_head); 80 if (IS_ERR(fd->bnode)) 81 return PTR_ERR(fd->bnode); 82 fd->record = -1; 83 } 84 new_node = NULL; 85 key_len = (fd->search_key->key_len | 1) + 1; 86again: 87 /* new record idx and complete record size */ 88 rec = fd->record + 1; 89 size = key_len + entry_len; 90 91 node = fd->bnode; 92 hfs_bnode_dump(node); 93 /* get last offset */ 94 end_rec_off = tree->node_size - (node->num_recs + 1) * 2; 95 end_off = hfs_bnode_read_u16(node, end_rec_off); 96 end_rec_off -= 2; 97 dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", rec, size, end_off, end_rec_off); 98 if (size > end_rec_off - end_off) { 99 if (new_node) 100 panic("not enough room!\n"); 101 new_node = hfs_bnode_split(fd); 102 if (IS_ERR(new_node)) 103 return PTR_ERR(new_node); 104 goto again; 105 } 106 if (node->type == HFS_NODE_LEAF) { 107 tree->leaf_count++; 108 mark_inode_dirty(tree->inode); 109 } 110 node->num_recs++; 111 /* write new last offset */ 112 hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), 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 130skip: 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 if (new_node) { 136 /* update parent key if we inserted a key 137 * at the start of the first node 138 */ 139 if (!rec && new_node != node) 140 hfs_brec_update_parent(fd); 141 142 hfs_bnode_put(fd->bnode); 143 if (!new_node->parent) { 144 hfs_btree_inc_height(tree); 145 new_node->parent = tree->root; 146 } 147 fd->bnode = hfs_bnode_find(tree, new_node->parent); 148 149 /* create index data entry */ 150 cnid = cpu_to_be32(new_node->this); 151 entry = &cnid; 152 entry_len = sizeof(cnid); 153 154 /* get index key */ 155 hfs_bnode_read_key(new_node, fd->search_key, 14); 156 __hfs_brec_find(fd->bnode, fd); 157 158 hfs_bnode_put(new_node); 159 new_node = NULL; 160 161 if (tree->attributes & HFS_TREE_VARIDXKEYS) 162 key_len = fd->search_key->key_len + 1; 163 else { 164 fd->search_key->key_len = tree->max_key_len; 165 key_len = tree->max_key_len + 1; 166 } 167 goto again; 168 } 169 170 if (!rec) 171 hfs_brec_update_parent(fd); 172 173 return 0; 174} 175 176int hfs_brec_remove(struct hfs_find_data *fd) 177{ 178 struct hfs_btree *tree; 179 struct hfs_bnode *node, *parent; 180 int end_off, rec_off, data_off, size; 181 182 tree = fd->tree; 183 node = fd->bnode; 184again: 185 rec_off = tree->node_size - (fd->record + 2) * 2; 186 end_off = tree->node_size - (node->num_recs + 1) * 2; 187 188 if (node->type == HFS_NODE_LEAF) { 189 tree->leaf_count--; 190 mark_inode_dirty(tree->inode); 191 } 192 hfs_bnode_dump(node); 193 dprint(DBG_BNODE_MOD, "remove_rec: %d, %d\n", fd->record, fd->keylength + fd->entrylength); 194 if (!--node->num_recs) { 195 hfs_bnode_unlink(node); 196 if (!node->parent) 197 return 0; 198 parent = hfs_bnode_find(tree, node->parent); 199 if (IS_ERR(parent)) 200 return PTR_ERR(parent); 201 hfs_bnode_put(node); 202 node = fd->bnode = parent; 203 204 __hfs_brec_find(node, fd); 205 goto again; 206 } 207 hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); 208 209 if (rec_off == end_off) 210 goto skip; 211 size = fd->keylength + fd->entrylength; 212 213 do { 214 data_off = hfs_bnode_read_u16(node, rec_off); 215 hfs_bnode_write_u16(node, rec_off + 2, data_off - size); 216 rec_off -= 2; 217 } while (rec_off >= end_off); 218 219 /* fill hole */ 220 hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size, 221 data_off - fd->keyoffset - size); 222skip: 223 hfs_bnode_dump(node); 224 if (!fd->record) 225 hfs_brec_update_parent(fd); 226 return 0; 227} 228 229static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd) 230{ 231 struct hfs_btree *tree; 232 struct hfs_bnode *node, *new_node, *next_node; 233 struct hfs_bnode_desc node_desc; 234 int num_recs, new_rec_off, new_off, old_rec_off; 235 int data_start, data_end, size; 236 237 tree = fd->tree; 238 node = fd->bnode; 239 new_node = hfs_bmap_alloc(tree); 240 if (IS_ERR(new_node)) 241 return new_node; 242 hfs_bnode_get(node); 243 dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n", 244 node->this, new_node->this, node->next); 245 new_node->next = node->next; 246 new_node->prev = node->this; 247 new_node->parent = node->parent; 248 new_node->type = node->type; 249 new_node->height = node->height; 250 251 if (node->next) 252 next_node = hfs_bnode_find(tree, node->next); 253 else 254 next_node = NULL; 255 256 if (IS_ERR(next_node)) { 257 hfs_bnode_put(node); 258 hfs_bnode_put(new_node); 259 return next_node; 260 } 261 262 size = tree->node_size / 2 - node->num_recs * 2 - 14; 263 old_rec_off = tree->node_size - 4; 264 num_recs = 1; 265 for (;;) { 266 data_start = hfs_bnode_read_u16(node, old_rec_off); 267 if (data_start > size) 268 break; 269 old_rec_off -= 2; 270 if (++num_recs < node->num_recs) 271 continue; 272 /* panic? */ 273 hfs_bnode_put(node); 274 hfs_bnode_put(new_node); 275 if (next_node) 276 hfs_bnode_put(next_node); 277 return ERR_PTR(-ENOSPC); 278 } 279 280 if (fd->record + 1 < num_recs) { 281 /* new record is in the lower half, 282 * so leave some more space there 283 */ 284 old_rec_off += 2; 285 num_recs--; 286 data_start = hfs_bnode_read_u16(node, old_rec_off); 287 } else { 288 hfs_bnode_put(node); 289 hfs_bnode_get(new_node); 290 fd->bnode = new_node; 291 fd->record -= num_recs; 292 fd->keyoffset -= data_start - 14; 293 fd->entryoffset -= data_start - 14; 294 } 295 new_node->num_recs = node->num_recs - num_recs; 296 node->num_recs = num_recs; 297 298 new_rec_off = tree->node_size - 2; 299 new_off = 14; 300 size = data_start - new_off; 301 num_recs = new_node->num_recs; 302 data_end = data_start; 303 while (num_recs) { 304 hfs_bnode_write_u16(new_node, new_rec_off, new_off); 305 old_rec_off -= 2; 306 new_rec_off -= 2; 307 data_end = hfs_bnode_read_u16(node, old_rec_off); 308 new_off = data_end - size; 309 num_recs--; 310 } 311 hfs_bnode_write_u16(new_node, new_rec_off, new_off); 312 hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start); 313 314 /* update new bnode header */ 315 node_desc.next = cpu_to_be32(new_node->next); 316 node_desc.prev = cpu_to_be32(new_node->prev); 317 node_desc.type = new_node->type; 318 node_desc.height = new_node->height; 319 node_desc.num_recs = cpu_to_be16(new_node->num_recs); 320 node_desc.reserved = 0; 321 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); 322 323 /* update previous bnode header */ 324 node->next = new_node->this; 325 hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc)); 326 node_desc.next = cpu_to_be32(node->next); 327 node_desc.num_recs = cpu_to_be16(node->num_recs); 328 hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc)); 329 330 /* update next bnode header */ 331 if (next_node) { 332 next_node->prev = new_node->this; 333 hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc)); 334 node_desc.prev = cpu_to_be32(next_node->prev); 335 hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc)); 336 hfs_bnode_put(next_node); 337 } else if (node->this == tree->leaf_tail) { 338 /* if there is no next node, this might be the new tail */ 339 tree->leaf_tail = new_node->this; 340 mark_inode_dirty(tree->inode); 341 } 342 343 hfs_bnode_dump(node); 344 hfs_bnode_dump(new_node); 345 hfs_bnode_put(node); 346 347 return new_node; 348} 349 350static int hfs_brec_update_parent(struct hfs_find_data *fd) 351{ 352 struct hfs_btree *tree; 353 struct hfs_bnode *node, *new_node, *parent; 354 int newkeylen, diff; 355 int rec, rec_off, end_rec_off; 356 int start_off, end_off; 357 358 tree = fd->tree; 359 node = fd->bnode; 360 new_node = NULL; 361 if (!node->parent) 362 return 0; 363 364again: 365 parent = hfs_bnode_find(tree, node->parent); 366 if (IS_ERR(parent)) 367 return PTR_ERR(parent); 368 __hfs_brec_find(parent, fd); 369 hfs_bnode_dump(parent); 370 rec = fd->record; 371 372 /* size difference between old and new key */ 373 if (tree->attributes & HFS_TREE_VARIDXKEYS) 374 newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1; 375 else 376 fd->keylength = newkeylen = tree->max_key_len + 1; 377 dprint(DBG_BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen); 378 379 rec_off = tree->node_size - (rec + 2) * 2; 380 end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; 381 diff = newkeylen - fd->keylength; 382 if (!diff) 383 goto skip; 384 if (diff > 0) { 385 end_off = hfs_bnode_read_u16(parent, end_rec_off); 386 if (end_rec_off - end_off < diff) { 387 388 printk(KERN_DEBUG "hfs: splitting index node...\n"); 389 fd->bnode = parent; 390 new_node = hfs_bnode_split(fd); 391 if (IS_ERR(new_node)) 392 return PTR_ERR(new_node); 393 parent = fd->bnode; 394 rec = fd->record; 395 rec_off = tree->node_size - (rec + 2) * 2; 396 end_rec_off = tree->node_size - (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); 411skip: 412 hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen); 413 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) 414 hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1); 415 hfs_bnode_dump(parent); 416 417 hfs_bnode_put(node); 418 node = parent; 419 420 if (new_node) { 421 __be32 cnid; 422 423 fd->bnode = hfs_bnode_find(tree, new_node->parent); 424 /* create index key and entry */ 425 hfs_bnode_read_key(new_node, fd->search_key, 14); 426 cnid = cpu_to_be32(new_node->this); 427 428 __hfs_brec_find(fd->bnode, fd); 429 hfs_brec_insert(fd, &cnid, sizeof(cnid)); 430 hfs_bnode_put(fd->bnode); 431 hfs_bnode_put(new_node); 432 433 if (!rec) { 434 if (new_node == node) 435 goto out; 436 /* restore search_key */ 437 hfs_bnode_read_key(node, fd->search_key, 14); 438 } 439 } 440 441 if (!rec && node->parent) 442 goto again; 443out: 444 fd->bnode = node; 445 return 0; 446} 447 448static int hfs_btree_inc_height(struct hfs_btree *tree) 449{ 450 struct hfs_bnode *node, *new_node; 451 struct hfs_bnode_desc node_desc; 452 int key_size, rec; 453 __be32 cnid; 454 455 node = NULL; 456 if (tree->root) { 457 node = hfs_bnode_find(tree, tree->root); 458 if (IS_ERR(node)) 459 return PTR_ERR(node); 460 } 461 new_node = hfs_bmap_alloc(tree); 462 if (IS_ERR(new_node)) { 463 hfs_bnode_put(node); 464 return PTR_ERR(new_node); 465 } 466 467 tree->root = new_node->this; 468 if (!tree->depth) { 469 tree->leaf_head = tree->leaf_tail = new_node->this; 470 new_node->type = HFS_NODE_LEAF; 471 new_node->num_recs = 0; 472 } else { 473 new_node->type = HFS_NODE_INDEX; 474 new_node->num_recs = 1; 475 } 476 new_node->parent = 0; 477 new_node->next = 0; 478 new_node->prev = 0; 479 new_node->height = ++tree->depth; 480 481 node_desc.next = cpu_to_be32(new_node->next); 482 node_desc.prev = cpu_to_be32(new_node->prev); 483 node_desc.type = new_node->type; 484 node_desc.height = new_node->height; 485 node_desc.num_recs = cpu_to_be16(new_node->num_recs); 486 node_desc.reserved = 0; 487 hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc)); 488 489 rec = tree->node_size - 2; 490 hfs_bnode_write_u16(new_node, rec, 14); 491 492 if (node) { 493 /* insert old root idx into new root */ 494 node->parent = tree->root; 495 if (node->type == HFS_NODE_LEAF || 496 tree->attributes & HFS_TREE_VARIDXKEYS) 497 key_size = hfs_bnode_read_u8(node, 14) + 1; 498 else 499 key_size = tree->max_key_len + 1; 500 hfs_bnode_copy(new_node, 14, node, 14, key_size); 501 502 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) { 503 key_size = tree->max_key_len + 1; 504 hfs_bnode_write_u8(new_node, 14, tree->max_key_len); 505 } 506 key_size = (key_size + 1) & -2; 507 cnid = cpu_to_be32(node->this); 508 hfs_bnode_write(new_node, &cnid, 14 + key_size, 4); 509 510 rec -= 2; 511 hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4); 512 513 hfs_bnode_put(node); 514 } 515 hfs_bnode_put(new_node); 516 mark_inode_dirty(tree->inode); 517 518 return 0; 519} 520