Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/hfsplus/bnode.c |
| 3 | * |
| 4 | * Copyright (C) 2001 |
| 5 | * Brad Boyer (flar@allandria.com) |
| 6 | * (C) 2003 Ardis Technologies <roman@ardistech.com> |
| 7 | * |
| 8 | * Handle basic btree node operations |
| 9 | */ |
| 10 | |
| 11 | #include <linux/string.h> |
| 12 | #include <linux/slab.h> |
| 13 | #include <linux/pagemap.h> |
| 14 | #include <linux/fs.h> |
| 15 | #include <linux/swap.h> |
| 16 | #include <linux/version.h> |
| 17 | |
| 18 | #include "hfsplus_fs.h" |
| 19 | #include "hfsplus_raw.h" |
| 20 | |
| 21 | #define REF_PAGES 0 |
| 22 | |
| 23 | /* Copy a specified range of bytes from the raw data of a node */ |
| 24 | void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len) |
| 25 | { |
| 26 | struct page **pagep; |
| 27 | int l; |
| 28 | |
| 29 | off += node->page_offset; |
| 30 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); |
| 31 | off &= ~PAGE_CACHE_MASK; |
| 32 | |
| 33 | l = min(len, (int)PAGE_CACHE_SIZE - off); |
| 34 | memcpy(buf, kmap(*pagep) + off, l); |
| 35 | kunmap(*pagep); |
| 36 | |
| 37 | while ((len -= l) != 0) { |
| 38 | buf += l; |
| 39 | l = min(len, (int)PAGE_CACHE_SIZE); |
| 40 | memcpy(buf, kmap(*++pagep), l); |
| 41 | kunmap(*pagep); |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off) |
| 46 | { |
| 47 | __be16 data; |
| 48 | // optimize later... |
| 49 | hfs_bnode_read(node, &data, off, 2); |
| 50 | return be16_to_cpu(data); |
| 51 | } |
| 52 | |
| 53 | u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off) |
| 54 | { |
| 55 | u8 data; |
| 56 | // optimize later... |
| 57 | hfs_bnode_read(node, &data, off, 1); |
| 58 | return data; |
| 59 | } |
| 60 | |
| 61 | void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off) |
| 62 | { |
| 63 | struct hfs_btree *tree; |
| 64 | int key_len; |
| 65 | |
| 66 | tree = node->tree; |
| 67 | if (node->type == HFS_NODE_LEAF || |
| 68 | tree->attributes & HFS_TREE_VARIDXKEYS) |
| 69 | key_len = hfs_bnode_read_u16(node, off) + 2; |
| 70 | else |
| 71 | key_len = tree->max_key_len + 2; |
| 72 | |
| 73 | hfs_bnode_read(node, key, off, key_len); |
| 74 | } |
| 75 | |
| 76 | void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len) |
| 77 | { |
| 78 | struct page **pagep; |
| 79 | int l; |
| 80 | |
| 81 | off += node->page_offset; |
| 82 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); |
| 83 | off &= ~PAGE_CACHE_MASK; |
| 84 | |
| 85 | l = min(len, (int)PAGE_CACHE_SIZE - off); |
| 86 | memcpy(kmap(*pagep) + off, buf, l); |
| 87 | set_page_dirty(*pagep); |
| 88 | kunmap(*pagep); |
| 89 | |
| 90 | while ((len -= l) != 0) { |
| 91 | buf += l; |
| 92 | l = min(len, (int)PAGE_CACHE_SIZE); |
| 93 | memcpy(kmap(*++pagep), buf, l); |
| 94 | set_page_dirty(*pagep); |
| 95 | kunmap(*pagep); |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data) |
| 100 | { |
| 101 | __be16 v = cpu_to_be16(data); |
| 102 | // optimize later... |
| 103 | hfs_bnode_write(node, &v, off, 2); |
| 104 | } |
| 105 | |
| 106 | void hfs_bnode_clear(struct hfs_bnode *node, int off, int len) |
| 107 | { |
| 108 | struct page **pagep; |
| 109 | int l; |
| 110 | |
| 111 | off += node->page_offset; |
| 112 | pagep = node->page + (off >> PAGE_CACHE_SHIFT); |
| 113 | off &= ~PAGE_CACHE_MASK; |
| 114 | |
| 115 | l = min(len, (int)PAGE_CACHE_SIZE - off); |
| 116 | memset(kmap(*pagep) + off, 0, l); |
| 117 | set_page_dirty(*pagep); |
| 118 | kunmap(*pagep); |
| 119 | |
| 120 | while ((len -= l) != 0) { |
| 121 | l = min(len, (int)PAGE_CACHE_SIZE); |
| 122 | memset(kmap(*++pagep), 0, l); |
| 123 | set_page_dirty(*pagep); |
| 124 | kunmap(*pagep); |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst, |
| 129 | struct hfs_bnode *src_node, int src, int len) |
| 130 | { |
| 131 | struct hfs_btree *tree; |
| 132 | struct page **src_page, **dst_page; |
| 133 | int l; |
| 134 | |
| 135 | dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len); |
| 136 | if (!len) |
| 137 | return; |
| 138 | tree = src_node->tree; |
| 139 | src += src_node->page_offset; |
| 140 | dst += dst_node->page_offset; |
| 141 | src_page = src_node->page + (src >> PAGE_CACHE_SHIFT); |
| 142 | src &= ~PAGE_CACHE_MASK; |
| 143 | dst_page = dst_node->page + (dst >> PAGE_CACHE_SHIFT); |
| 144 | dst &= ~PAGE_CACHE_MASK; |
| 145 | |
| 146 | if (src == dst) { |
| 147 | l = min(len, (int)PAGE_CACHE_SIZE - src); |
| 148 | memcpy(kmap(*dst_page) + src, kmap(*src_page) + src, l); |
| 149 | kunmap(*src_page); |
| 150 | set_page_dirty(*dst_page); |
| 151 | kunmap(*dst_page); |
| 152 | |
| 153 | while ((len -= l) != 0) { |
| 154 | l = min(len, (int)PAGE_CACHE_SIZE); |
| 155 | memcpy(kmap(*++dst_page), kmap(*++src_page), l); |
| 156 | kunmap(*src_page); |
| 157 | set_page_dirty(*dst_page); |
| 158 | kunmap(*dst_page); |
| 159 | } |
| 160 | } else { |
| 161 | void *src_ptr, *dst_ptr; |
| 162 | |
| 163 | do { |
| 164 | src_ptr = kmap(*src_page) + src; |
| 165 | dst_ptr = kmap(*dst_page) + dst; |
| 166 | if (PAGE_CACHE_SIZE - src < PAGE_CACHE_SIZE - dst) { |
| 167 | l = PAGE_CACHE_SIZE - src; |
| 168 | src = 0; |
| 169 | dst += l; |
| 170 | } else { |
| 171 | l = PAGE_CACHE_SIZE - dst; |
| 172 | src += l; |
| 173 | dst = 0; |
| 174 | } |
| 175 | l = min(len, l); |
| 176 | memcpy(dst_ptr, src_ptr, l); |
| 177 | kunmap(*src_page); |
| 178 | set_page_dirty(*dst_page); |
| 179 | kunmap(*dst_page); |
| 180 | if (!dst) |
| 181 | dst_page++; |
| 182 | else |
| 183 | src_page++; |
| 184 | } while ((len -= l)); |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len) |
| 189 | { |
| 190 | struct page **src_page, **dst_page; |
| 191 | int l; |
| 192 | |
| 193 | dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len); |
| 194 | if (!len) |
| 195 | return; |
| 196 | src += node->page_offset; |
| 197 | dst += node->page_offset; |
| 198 | if (dst > src) { |
| 199 | src += len - 1; |
| 200 | src_page = node->page + (src >> PAGE_CACHE_SHIFT); |
| 201 | src = (src & ~PAGE_CACHE_MASK) + 1; |
| 202 | dst += len - 1; |
| 203 | dst_page = node->page + (dst >> PAGE_CACHE_SHIFT); |
| 204 | dst = (dst & ~PAGE_CACHE_MASK) + 1; |
| 205 | |
| 206 | if (src == dst) { |
| 207 | while (src < len) { |
| 208 | memmove(kmap(*dst_page), kmap(*src_page), src); |
| 209 | kunmap(*src_page); |
| 210 | set_page_dirty(*dst_page); |
| 211 | kunmap(*dst_page); |
| 212 | len -= src; |
| 213 | src = PAGE_CACHE_SIZE; |
| 214 | src_page--; |
| 215 | dst_page--; |
| 216 | } |
| 217 | src -= len; |
| 218 | memmove(kmap(*dst_page) + src, kmap(*src_page) + src, len); |
| 219 | kunmap(*src_page); |
| 220 | set_page_dirty(*dst_page); |
| 221 | kunmap(*dst_page); |
| 222 | } else { |
| 223 | void *src_ptr, *dst_ptr; |
| 224 | |
| 225 | do { |
| 226 | src_ptr = kmap(*src_page) + src; |
| 227 | dst_ptr = kmap(*dst_page) + dst; |
| 228 | if (src < dst) { |
| 229 | l = src; |
| 230 | src = PAGE_CACHE_SIZE; |
| 231 | dst -= l; |
| 232 | } else { |
| 233 | l = dst; |
| 234 | src -= l; |
| 235 | dst = PAGE_CACHE_SIZE; |
| 236 | } |
| 237 | l = min(len, l); |
| 238 | memmove(dst_ptr - l, src_ptr - l, l); |
| 239 | kunmap(*src_page); |
| 240 | set_page_dirty(*dst_page); |
| 241 | kunmap(*dst_page); |
| 242 | if (dst == PAGE_CACHE_SIZE) |
| 243 | dst_page--; |
| 244 | else |
| 245 | src_page--; |
| 246 | } while ((len -= l)); |
| 247 | } |
| 248 | } else { |
| 249 | src_page = node->page + (src >> PAGE_CACHE_SHIFT); |
| 250 | src &= ~PAGE_CACHE_MASK; |
| 251 | dst_page = node->page + (dst >> PAGE_CACHE_SHIFT); |
| 252 | dst &= ~PAGE_CACHE_MASK; |
| 253 | |
| 254 | if (src == dst) { |
| 255 | l = min(len, (int)PAGE_CACHE_SIZE - src); |
| 256 | memmove(kmap(*dst_page) + src, kmap(*src_page) + src, l); |
| 257 | kunmap(*src_page); |
| 258 | set_page_dirty(*dst_page); |
| 259 | kunmap(*dst_page); |
| 260 | |
| 261 | while ((len -= l) != 0) { |
| 262 | l = min(len, (int)PAGE_CACHE_SIZE); |
| 263 | memmove(kmap(*++dst_page), kmap(*++src_page), l); |
| 264 | kunmap(*src_page); |
| 265 | set_page_dirty(*dst_page); |
| 266 | kunmap(*dst_page); |
| 267 | } |
| 268 | } else { |
| 269 | void *src_ptr, *dst_ptr; |
| 270 | |
| 271 | do { |
| 272 | src_ptr = kmap(*src_page) + src; |
| 273 | dst_ptr = kmap(*dst_page) + dst; |
| 274 | if (PAGE_CACHE_SIZE - src < PAGE_CACHE_SIZE - dst) { |
| 275 | l = PAGE_CACHE_SIZE - src; |
| 276 | src = 0; |
| 277 | dst += l; |
| 278 | } else { |
| 279 | l = PAGE_CACHE_SIZE - dst; |
| 280 | src += l; |
| 281 | dst = 0; |
| 282 | } |
| 283 | l = min(len, l); |
| 284 | memmove(dst_ptr, src_ptr, l); |
| 285 | kunmap(*src_page); |
| 286 | set_page_dirty(*dst_page); |
| 287 | kunmap(*dst_page); |
| 288 | if (!dst) |
| 289 | dst_page++; |
| 290 | else |
| 291 | src_page++; |
| 292 | } while ((len -= l)); |
| 293 | } |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | void hfs_bnode_dump(struct hfs_bnode *node) |
| 298 | { |
| 299 | struct hfs_bnode_desc desc; |
| 300 | __be32 cnid; |
| 301 | int i, off, key_off; |
| 302 | |
| 303 | dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this); |
| 304 | hfs_bnode_read(node, &desc, 0, sizeof(desc)); |
| 305 | dprint(DBG_BNODE_MOD, "%d, %d, %d, %d, %d\n", |
| 306 | be32_to_cpu(desc.next), be32_to_cpu(desc.prev), |
| 307 | desc.type, desc.height, be16_to_cpu(desc.num_recs)); |
| 308 | |
| 309 | off = node->tree->node_size - 2; |
| 310 | for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) { |
| 311 | key_off = hfs_bnode_read_u16(node, off); |
| 312 | dprint(DBG_BNODE_MOD, " %d", key_off); |
| 313 | if (i && node->type == HFS_NODE_INDEX) { |
| 314 | int tmp; |
| 315 | |
| 316 | if (node->tree->attributes & HFS_TREE_VARIDXKEYS) |
| 317 | tmp = hfs_bnode_read_u16(node, key_off) + 2; |
| 318 | else |
| 319 | tmp = node->tree->max_key_len + 2; |
| 320 | dprint(DBG_BNODE_MOD, " (%d", tmp); |
| 321 | hfs_bnode_read(node, &cnid, key_off + tmp, 4); |
| 322 | dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid)); |
| 323 | } else if (i && node->type == HFS_NODE_LEAF) { |
| 324 | int tmp; |
| 325 | |
| 326 | tmp = hfs_bnode_read_u16(node, key_off); |
| 327 | dprint(DBG_BNODE_MOD, " (%d)", tmp); |
| 328 | } |
| 329 | } |
| 330 | dprint(DBG_BNODE_MOD, "\n"); |
| 331 | } |
| 332 | |
| 333 | void hfs_bnode_unlink(struct hfs_bnode *node) |
| 334 | { |
| 335 | struct hfs_btree *tree; |
| 336 | struct hfs_bnode *tmp; |
| 337 | __be32 cnid; |
| 338 | |
| 339 | tree = node->tree; |
| 340 | if (node->prev) { |
| 341 | tmp = hfs_bnode_find(tree, node->prev); |
| 342 | if (IS_ERR(tmp)) |
| 343 | return; |
| 344 | tmp->next = node->next; |
| 345 | cnid = cpu_to_be32(tmp->next); |
| 346 | hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4); |
| 347 | hfs_bnode_put(tmp); |
| 348 | } else if (node->type == HFS_NODE_LEAF) |
| 349 | tree->leaf_head = node->next; |
| 350 | |
| 351 | if (node->next) { |
| 352 | tmp = hfs_bnode_find(tree, node->next); |
| 353 | if (IS_ERR(tmp)) |
| 354 | return; |
| 355 | tmp->prev = node->prev; |
| 356 | cnid = cpu_to_be32(tmp->prev); |
| 357 | hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4); |
| 358 | hfs_bnode_put(tmp); |
| 359 | } else if (node->type == HFS_NODE_LEAF) |
| 360 | tree->leaf_tail = node->prev; |
| 361 | |
| 362 | // move down? |
| 363 | if (!node->prev && !node->next) { |
| 364 | printk("hfs_btree_del_level\n"); |
| 365 | } |
| 366 | if (!node->parent) { |
| 367 | tree->root = 0; |
| 368 | tree->depth = 0; |
| 369 | } |
| 370 | set_bit(HFS_BNODE_DELETED, &node->flags); |
| 371 | } |
| 372 | |
| 373 | static inline int hfs_bnode_hash(u32 num) |
| 374 | { |
| 375 | num = (num >> 16) + num; |
| 376 | num += num >> 8; |
| 377 | return num & (NODE_HASH_SIZE - 1); |
| 378 | } |
| 379 | |
| 380 | struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid) |
| 381 | { |
| 382 | struct hfs_bnode *node; |
| 383 | |
| 384 | if (cnid >= tree->node_count) { |
| 385 | printk("HFS+-fs: request for non-existent node %d in B*Tree\n", cnid); |
| 386 | return NULL; |
| 387 | } |
| 388 | |
| 389 | for (node = tree->node_hash[hfs_bnode_hash(cnid)]; |
| 390 | node; node = node->next_hash) { |
| 391 | if (node->this == cnid) { |
| 392 | return node; |
| 393 | } |
| 394 | } |
| 395 | return NULL; |
| 396 | } |
| 397 | |
| 398 | static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid) |
| 399 | { |
| 400 | struct super_block *sb; |
| 401 | struct hfs_bnode *node, *node2; |
| 402 | struct address_space *mapping; |
| 403 | struct page *page; |
| 404 | int size, block, i, hash; |
| 405 | loff_t off; |
| 406 | |
| 407 | if (cnid >= tree->node_count) { |
| 408 | printk("HFS+-fs: request for non-existent node %d in B*Tree\n", cnid); |
| 409 | return NULL; |
| 410 | } |
| 411 | |
| 412 | sb = tree->inode->i_sb; |
| 413 | size = sizeof(struct hfs_bnode) + tree->pages_per_bnode * |
| 414 | sizeof(struct page *); |
| 415 | node = kmalloc(size, GFP_KERNEL); |
| 416 | if (!node) |
| 417 | return NULL; |
| 418 | memset(node, 0, size); |
| 419 | node->tree = tree; |
| 420 | node->this = cnid; |
| 421 | set_bit(HFS_BNODE_NEW, &node->flags); |
| 422 | atomic_set(&node->refcnt, 1); |
| 423 | dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n", |
| 424 | node->tree->cnid, node->this); |
| 425 | init_waitqueue_head(&node->lock_wq); |
| 426 | spin_lock(&tree->hash_lock); |
| 427 | node2 = hfs_bnode_findhash(tree, cnid); |
| 428 | if (!node2) { |
| 429 | hash = hfs_bnode_hash(cnid); |
| 430 | node->next_hash = tree->node_hash[hash]; |
| 431 | tree->node_hash[hash] = node; |
| 432 | tree->node_hash_cnt++; |
| 433 | } else { |
| 434 | spin_unlock(&tree->hash_lock); |
| 435 | kfree(node); |
| 436 | wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags)); |
| 437 | return node2; |
| 438 | } |
| 439 | spin_unlock(&tree->hash_lock); |
| 440 | |
| 441 | mapping = tree->inode->i_mapping; |
| 442 | off = (loff_t)cnid << tree->node_size_shift; |
| 443 | block = off >> PAGE_CACHE_SHIFT; |
| 444 | node->page_offset = off & ~PAGE_CACHE_MASK; |
| 445 | for (i = 0; i < tree->pages_per_bnode; block++, i++) { |
| 446 | page = read_cache_page(mapping, block, (filler_t *)mapping->a_ops->readpage, NULL); |
| 447 | if (IS_ERR(page)) |
| 448 | goto fail; |
| 449 | if (PageError(page)) { |
| 450 | page_cache_release(page); |
| 451 | goto fail; |
| 452 | } |
| 453 | #if !REF_PAGES |
| 454 | page_cache_release(page); |
| 455 | #endif |
| 456 | node->page[i] = page; |
| 457 | } |
| 458 | |
| 459 | return node; |
| 460 | fail: |
| 461 | set_bit(HFS_BNODE_ERROR, &node->flags); |
| 462 | return node; |
| 463 | } |
| 464 | |
| 465 | void hfs_bnode_unhash(struct hfs_bnode *node) |
| 466 | { |
| 467 | struct hfs_bnode **p; |
| 468 | |
| 469 | dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n", |
| 470 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); |
| 471 | for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)]; |
| 472 | *p && *p != node; p = &(*p)->next_hash) |
| 473 | ; |
| 474 | if (!*p) |
| 475 | BUG(); |
| 476 | *p = node->next_hash; |
| 477 | node->tree->node_hash_cnt--; |
| 478 | } |
| 479 | |
| 480 | /* Load a particular node out of a tree */ |
| 481 | struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num) |
| 482 | { |
| 483 | struct hfs_bnode *node; |
| 484 | struct hfs_bnode_desc *desc; |
| 485 | int i, rec_off, off, next_off; |
| 486 | int entry_size, key_size; |
| 487 | |
| 488 | spin_lock(&tree->hash_lock); |
| 489 | node = hfs_bnode_findhash(tree, num); |
| 490 | if (node) { |
| 491 | hfs_bnode_get(node); |
| 492 | spin_unlock(&tree->hash_lock); |
| 493 | wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags)); |
| 494 | if (test_bit(HFS_BNODE_ERROR, &node->flags)) |
| 495 | goto node_error; |
| 496 | return node; |
| 497 | } |
| 498 | spin_unlock(&tree->hash_lock); |
| 499 | node = __hfs_bnode_create(tree, num); |
| 500 | if (!node) |
| 501 | return ERR_PTR(-ENOMEM); |
| 502 | if (test_bit(HFS_BNODE_ERROR, &node->flags)) |
| 503 | goto node_error; |
| 504 | if (!test_bit(HFS_BNODE_NEW, &node->flags)) |
| 505 | return node; |
| 506 | |
| 507 | desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset); |
| 508 | node->prev = be32_to_cpu(desc->prev); |
| 509 | node->next = be32_to_cpu(desc->next); |
| 510 | node->num_recs = be16_to_cpu(desc->num_recs); |
| 511 | node->type = desc->type; |
| 512 | node->height = desc->height; |
| 513 | kunmap(node->page[0]); |
| 514 | |
| 515 | switch (node->type) { |
| 516 | case HFS_NODE_HEADER: |
| 517 | case HFS_NODE_MAP: |
| 518 | if (node->height != 0) |
| 519 | goto node_error; |
| 520 | break; |
| 521 | case HFS_NODE_LEAF: |
| 522 | if (node->height != 1) |
| 523 | goto node_error; |
| 524 | break; |
| 525 | case HFS_NODE_INDEX: |
| 526 | if (node->height <= 1 || node->height > tree->depth) |
| 527 | goto node_error; |
| 528 | break; |
| 529 | default: |
| 530 | goto node_error; |
| 531 | } |
| 532 | |
| 533 | rec_off = tree->node_size - 2; |
| 534 | off = hfs_bnode_read_u16(node, rec_off); |
| 535 | if (off != sizeof(struct hfs_bnode_desc)) |
| 536 | goto node_error; |
| 537 | for (i = 1; i <= node->num_recs; off = next_off, i++) { |
| 538 | rec_off -= 2; |
| 539 | next_off = hfs_bnode_read_u16(node, rec_off); |
| 540 | if (next_off <= off || |
| 541 | next_off > tree->node_size || |
| 542 | next_off & 1) |
| 543 | goto node_error; |
| 544 | entry_size = next_off - off; |
| 545 | if (node->type != HFS_NODE_INDEX && |
| 546 | node->type != HFS_NODE_LEAF) |
| 547 | continue; |
| 548 | key_size = hfs_bnode_read_u16(node, off) + 2; |
| 549 | if (key_size >= entry_size || key_size & 1) |
| 550 | goto node_error; |
| 551 | } |
| 552 | clear_bit(HFS_BNODE_NEW, &node->flags); |
| 553 | wake_up(&node->lock_wq); |
| 554 | return node; |
| 555 | |
| 556 | node_error: |
| 557 | set_bit(HFS_BNODE_ERROR, &node->flags); |
| 558 | clear_bit(HFS_BNODE_NEW, &node->flags); |
| 559 | wake_up(&node->lock_wq); |
| 560 | hfs_bnode_put(node); |
| 561 | return ERR_PTR(-EIO); |
| 562 | } |
| 563 | |
| 564 | void hfs_bnode_free(struct hfs_bnode *node) |
| 565 | { |
| 566 | //int i; |
| 567 | |
| 568 | //for (i = 0; i < node->tree->pages_per_bnode; i++) |
| 569 | // if (node->page[i]) |
| 570 | // page_cache_release(node->page[i]); |
| 571 | kfree(node); |
| 572 | } |
| 573 | |
| 574 | struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num) |
| 575 | { |
| 576 | struct hfs_bnode *node; |
| 577 | struct page **pagep; |
| 578 | int i; |
| 579 | |
| 580 | spin_lock(&tree->hash_lock); |
| 581 | node = hfs_bnode_findhash(tree, num); |
| 582 | spin_unlock(&tree->hash_lock); |
| 583 | if (node) { |
| 584 | printk("new node %u already hashed?\n", num); |
| 585 | BUG(); |
| 586 | } |
| 587 | node = __hfs_bnode_create(tree, num); |
| 588 | if (!node) |
| 589 | return ERR_PTR(-ENOMEM); |
| 590 | if (test_bit(HFS_BNODE_ERROR, &node->flags)) { |
| 591 | hfs_bnode_put(node); |
| 592 | return ERR_PTR(-EIO); |
| 593 | } |
| 594 | |
| 595 | pagep = node->page; |
| 596 | memset(kmap(*pagep) + node->page_offset, 0, |
| 597 | min((int)PAGE_CACHE_SIZE, (int)tree->node_size)); |
| 598 | set_page_dirty(*pagep); |
| 599 | kunmap(*pagep); |
| 600 | for (i = 1; i < tree->pages_per_bnode; i++) { |
| 601 | memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE); |
| 602 | set_page_dirty(*pagep); |
| 603 | kunmap(*pagep); |
| 604 | } |
| 605 | clear_bit(HFS_BNODE_NEW, &node->flags); |
| 606 | wake_up(&node->lock_wq); |
| 607 | |
| 608 | return node; |
| 609 | } |
| 610 | |
| 611 | void hfs_bnode_get(struct hfs_bnode *node) |
| 612 | { |
| 613 | if (node) { |
| 614 | atomic_inc(&node->refcnt); |
| 615 | #if REF_PAGES |
| 616 | { |
| 617 | int i; |
| 618 | for (i = 0; i < node->tree->pages_per_bnode; i++) |
| 619 | get_page(node->page[i]); |
| 620 | } |
| 621 | #endif |
| 622 | dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n", |
| 623 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); |
| 624 | } |
| 625 | } |
| 626 | |
| 627 | /* Dispose of resources used by a node */ |
| 628 | void hfs_bnode_put(struct hfs_bnode *node) |
| 629 | { |
| 630 | if (node) { |
| 631 | struct hfs_btree *tree = node->tree; |
| 632 | int i; |
| 633 | |
| 634 | dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n", |
| 635 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); |
| 636 | if (!atomic_read(&node->refcnt)) |
| 637 | BUG(); |
| 638 | if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock)) { |
| 639 | #if REF_PAGES |
| 640 | for (i = 0; i < tree->pages_per_bnode; i++) |
| 641 | put_page(node->page[i]); |
| 642 | #endif |
| 643 | return; |
| 644 | } |
| 645 | for (i = 0; i < tree->pages_per_bnode; i++) { |
Roman Zippel | 74f9c9c | 2005-08-01 21:11:41 -0700 | [diff] [blame^] | 646 | if (!node->page[i]) |
| 647 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | mark_page_accessed(node->page[i]); |
| 649 | #if REF_PAGES |
| 650 | put_page(node->page[i]); |
| 651 | #endif |
| 652 | } |
| 653 | |
| 654 | if (test_bit(HFS_BNODE_DELETED, &node->flags)) { |
| 655 | hfs_bnode_unhash(node); |
| 656 | spin_unlock(&tree->hash_lock); |
| 657 | hfs_bmap_free(node); |
| 658 | hfs_bnode_free(node); |
| 659 | return; |
| 660 | } |
| 661 | spin_unlock(&tree->hash_lock); |
| 662 | } |
| 663 | } |
| 664 | |