Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/hfs/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/pagemap.h> |
| 12 | #include <linux/swap.h> |
| 13 | |
| 14 | #include "btree.h" |
| 15 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | void hfs_bnode_read(struct hfs_bnode *node, void *buf, |
| 17 | int off, int len) |
| 18 | { |
| 19 | struct page *page; |
| 20 | |
| 21 | off += node->page_offset; |
| 22 | page = node->page[0]; |
| 23 | |
| 24 | memcpy(buf, kmap(page) + off, len); |
| 25 | kunmap(page); |
| 26 | } |
| 27 | |
| 28 | u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off) |
| 29 | { |
| 30 | __be16 data; |
| 31 | // optimize later... |
| 32 | hfs_bnode_read(node, &data, off, 2); |
| 33 | return be16_to_cpu(data); |
| 34 | } |
| 35 | |
| 36 | u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off) |
| 37 | { |
| 38 | u8 data; |
| 39 | // optimize later... |
| 40 | hfs_bnode_read(node, &data, off, 1); |
| 41 | return data; |
| 42 | } |
| 43 | |
| 44 | void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off) |
| 45 | { |
| 46 | struct hfs_btree *tree; |
| 47 | int key_len; |
| 48 | |
| 49 | tree = node->tree; |
| 50 | if (node->type == HFS_NODE_LEAF || |
| 51 | tree->attributes & HFS_TREE_VARIDXKEYS) |
| 52 | key_len = hfs_bnode_read_u8(node, off) + 1; |
| 53 | else |
| 54 | key_len = tree->max_key_len + 1; |
| 55 | |
| 56 | hfs_bnode_read(node, key, off, key_len); |
| 57 | } |
| 58 | |
| 59 | void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len) |
| 60 | { |
| 61 | struct page *page; |
| 62 | |
| 63 | off += node->page_offset; |
| 64 | page = node->page[0]; |
| 65 | |
| 66 | memcpy(kmap(page) + off, buf, len); |
| 67 | kunmap(page); |
| 68 | set_page_dirty(page); |
| 69 | } |
| 70 | |
| 71 | void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data) |
| 72 | { |
| 73 | __be16 v = cpu_to_be16(data); |
| 74 | // optimize later... |
| 75 | hfs_bnode_write(node, &v, off, 2); |
| 76 | } |
| 77 | |
| 78 | void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data) |
| 79 | { |
| 80 | // optimize later... |
| 81 | hfs_bnode_write(node, &data, off, 1); |
| 82 | } |
| 83 | |
| 84 | void hfs_bnode_clear(struct hfs_bnode *node, int off, int len) |
| 85 | { |
| 86 | struct page *page; |
| 87 | |
| 88 | off += node->page_offset; |
| 89 | page = node->page[0]; |
| 90 | |
| 91 | memset(kmap(page) + off, 0, len); |
| 92 | kunmap(page); |
| 93 | set_page_dirty(page); |
| 94 | } |
| 95 | |
| 96 | void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst, |
| 97 | struct hfs_bnode *src_node, int src, int len) |
| 98 | { |
| 99 | struct hfs_btree *tree; |
| 100 | struct page *src_page, *dst_page; |
| 101 | |
| 102 | dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len); |
| 103 | if (!len) |
| 104 | return; |
| 105 | tree = src_node->tree; |
| 106 | src += src_node->page_offset; |
| 107 | dst += dst_node->page_offset; |
| 108 | src_page = src_node->page[0]; |
| 109 | dst_page = dst_node->page[0]; |
| 110 | |
| 111 | memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len); |
| 112 | kunmap(src_page); |
| 113 | kunmap(dst_page); |
| 114 | set_page_dirty(dst_page); |
| 115 | } |
| 116 | |
| 117 | void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len) |
| 118 | { |
| 119 | struct page *page; |
| 120 | void *ptr; |
| 121 | |
| 122 | dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len); |
| 123 | if (!len) |
| 124 | return; |
| 125 | src += node->page_offset; |
| 126 | dst += node->page_offset; |
| 127 | page = node->page[0]; |
| 128 | ptr = kmap(page); |
| 129 | memmove(ptr + dst, ptr + src, len); |
| 130 | kunmap(page); |
| 131 | set_page_dirty(page); |
| 132 | } |
| 133 | |
| 134 | void hfs_bnode_dump(struct hfs_bnode *node) |
| 135 | { |
| 136 | struct hfs_bnode_desc desc; |
| 137 | __be32 cnid; |
| 138 | int i, off, key_off; |
| 139 | |
| 140 | dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this); |
| 141 | hfs_bnode_read(node, &desc, 0, sizeof(desc)); |
| 142 | dprint(DBG_BNODE_MOD, "%d, %d, %d, %d, %d\n", |
| 143 | be32_to_cpu(desc.next), be32_to_cpu(desc.prev), |
| 144 | desc.type, desc.height, be16_to_cpu(desc.num_recs)); |
| 145 | |
| 146 | off = node->tree->node_size - 2; |
| 147 | for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) { |
| 148 | key_off = hfs_bnode_read_u16(node, off); |
| 149 | dprint(DBG_BNODE_MOD, " %d", key_off); |
| 150 | if (i && node->type == HFS_NODE_INDEX) { |
| 151 | int tmp; |
| 152 | |
| 153 | if (node->tree->attributes & HFS_TREE_VARIDXKEYS) |
| 154 | tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1; |
| 155 | else |
| 156 | tmp = node->tree->max_key_len + 1; |
| 157 | dprint(DBG_BNODE_MOD, " (%d,%d", tmp, hfs_bnode_read_u8(node, key_off)); |
| 158 | hfs_bnode_read(node, &cnid, key_off + tmp, 4); |
| 159 | dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid)); |
| 160 | } else if (i && node->type == HFS_NODE_LEAF) { |
| 161 | int tmp; |
| 162 | |
| 163 | tmp = hfs_bnode_read_u8(node, key_off); |
| 164 | dprint(DBG_BNODE_MOD, " (%d)", tmp); |
| 165 | } |
| 166 | } |
| 167 | dprint(DBG_BNODE_MOD, "\n"); |
| 168 | } |
| 169 | |
| 170 | void hfs_bnode_unlink(struct hfs_bnode *node) |
| 171 | { |
| 172 | struct hfs_btree *tree; |
| 173 | struct hfs_bnode *tmp; |
| 174 | __be32 cnid; |
| 175 | |
| 176 | tree = node->tree; |
| 177 | if (node->prev) { |
| 178 | tmp = hfs_bnode_find(tree, node->prev); |
| 179 | if (IS_ERR(tmp)) |
| 180 | return; |
| 181 | tmp->next = node->next; |
| 182 | cnid = cpu_to_be32(tmp->next); |
| 183 | hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4); |
| 184 | hfs_bnode_put(tmp); |
| 185 | } else if (node->type == HFS_NODE_LEAF) |
| 186 | tree->leaf_head = node->next; |
| 187 | |
| 188 | if (node->next) { |
| 189 | tmp = hfs_bnode_find(tree, node->next); |
| 190 | if (IS_ERR(tmp)) |
| 191 | return; |
| 192 | tmp->prev = node->prev; |
| 193 | cnid = cpu_to_be32(tmp->prev); |
| 194 | hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4); |
| 195 | hfs_bnode_put(tmp); |
| 196 | } else if (node->type == HFS_NODE_LEAF) |
| 197 | tree->leaf_tail = node->prev; |
| 198 | |
| 199 | // move down? |
| 200 | if (!node->prev && !node->next) { |
Roman Zippel | 7cf3cc3 | 2006-01-18 17:43:07 -0800 | [diff] [blame] | 201 | printk(KERN_DEBUG "hfs_btree_del_level\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | } |
| 203 | if (!node->parent) { |
| 204 | tree->root = 0; |
| 205 | tree->depth = 0; |
| 206 | } |
| 207 | set_bit(HFS_BNODE_DELETED, &node->flags); |
| 208 | } |
| 209 | |
| 210 | static inline int hfs_bnode_hash(u32 num) |
| 211 | { |
| 212 | num = (num >> 16) + num; |
| 213 | num += num >> 8; |
| 214 | return num & (NODE_HASH_SIZE - 1); |
| 215 | } |
| 216 | |
| 217 | struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid) |
| 218 | { |
| 219 | struct hfs_bnode *node; |
| 220 | |
| 221 | if (cnid >= tree->node_count) { |
Roman Zippel | 7cf3cc3 | 2006-01-18 17:43:07 -0800 | [diff] [blame] | 222 | printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | return NULL; |
| 224 | } |
| 225 | |
| 226 | for (node = tree->node_hash[hfs_bnode_hash(cnid)]; |
| 227 | node; node = node->next_hash) { |
| 228 | if (node->this == cnid) { |
| 229 | return node; |
| 230 | } |
| 231 | } |
| 232 | return NULL; |
| 233 | } |
| 234 | |
| 235 | static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid) |
| 236 | { |
| 237 | struct super_block *sb; |
| 238 | struct hfs_bnode *node, *node2; |
| 239 | struct address_space *mapping; |
| 240 | struct page *page; |
| 241 | int size, block, i, hash; |
| 242 | loff_t off; |
| 243 | |
| 244 | if (cnid >= tree->node_count) { |
Roman Zippel | 7cf3cc3 | 2006-01-18 17:43:07 -0800 | [diff] [blame] | 245 | printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | return NULL; |
| 247 | } |
| 248 | |
| 249 | sb = tree->inode->i_sb; |
| 250 | size = sizeof(struct hfs_bnode) + tree->pages_per_bnode * |
| 251 | sizeof(struct page *); |
| 252 | node = kmalloc(size, GFP_KERNEL); |
| 253 | if (!node) |
| 254 | return NULL; |
| 255 | memset(node, 0, size); |
| 256 | node->tree = tree; |
| 257 | node->this = cnid; |
| 258 | set_bit(HFS_BNODE_NEW, &node->flags); |
| 259 | atomic_set(&node->refcnt, 1); |
| 260 | dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n", |
| 261 | node->tree->cnid, node->this); |
| 262 | init_waitqueue_head(&node->lock_wq); |
| 263 | spin_lock(&tree->hash_lock); |
| 264 | node2 = hfs_bnode_findhash(tree, cnid); |
| 265 | if (!node2) { |
| 266 | hash = hfs_bnode_hash(cnid); |
| 267 | node->next_hash = tree->node_hash[hash]; |
| 268 | tree->node_hash[hash] = node; |
| 269 | tree->node_hash_cnt++; |
| 270 | } else { |
| 271 | spin_unlock(&tree->hash_lock); |
| 272 | kfree(node); |
| 273 | wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags)); |
| 274 | return node2; |
| 275 | } |
| 276 | spin_unlock(&tree->hash_lock); |
| 277 | |
| 278 | mapping = tree->inode->i_mapping; |
| 279 | off = (loff_t)cnid * tree->node_size; |
| 280 | block = off >> PAGE_CACHE_SHIFT; |
| 281 | node->page_offset = off & ~PAGE_CACHE_MASK; |
| 282 | for (i = 0; i < tree->pages_per_bnode; i++) { |
Pekka Enberg | 090d2b1 | 2006-06-23 02:05:08 -0700 | [diff] [blame] | 283 | page = read_mapping_page(mapping, block++, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | if (IS_ERR(page)) |
| 285 | goto fail; |
| 286 | if (PageError(page)) { |
| 287 | page_cache_release(page); |
| 288 | goto fail; |
| 289 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | page_cache_release(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | node->page[i] = page; |
| 292 | } |
| 293 | |
| 294 | return node; |
| 295 | fail: |
| 296 | set_bit(HFS_BNODE_ERROR, &node->flags); |
| 297 | return node; |
| 298 | } |
| 299 | |
| 300 | void hfs_bnode_unhash(struct hfs_bnode *node) |
| 301 | { |
| 302 | struct hfs_bnode **p; |
| 303 | |
| 304 | dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n", |
| 305 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); |
| 306 | for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)]; |
| 307 | *p && *p != node; p = &(*p)->next_hash) |
| 308 | ; |
Eric Sesterhenn | 4d4ef9a | 2006-03-26 18:26:51 +0200 | [diff] [blame] | 309 | BUG_ON(!*p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | *p = node->next_hash; |
| 311 | node->tree->node_hash_cnt--; |
| 312 | } |
| 313 | |
| 314 | /* Load a particular node out of a tree */ |
| 315 | struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num) |
| 316 | { |
| 317 | struct hfs_bnode *node; |
| 318 | struct hfs_bnode_desc *desc; |
| 319 | int i, rec_off, off, next_off; |
| 320 | int entry_size, key_size; |
| 321 | |
| 322 | spin_lock(&tree->hash_lock); |
| 323 | node = hfs_bnode_findhash(tree, num); |
| 324 | if (node) { |
| 325 | hfs_bnode_get(node); |
| 326 | spin_unlock(&tree->hash_lock); |
| 327 | wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags)); |
| 328 | if (test_bit(HFS_BNODE_ERROR, &node->flags)) |
| 329 | goto node_error; |
| 330 | return node; |
| 331 | } |
| 332 | spin_unlock(&tree->hash_lock); |
| 333 | node = __hfs_bnode_create(tree, num); |
| 334 | if (!node) |
| 335 | return ERR_PTR(-ENOMEM); |
| 336 | if (test_bit(HFS_BNODE_ERROR, &node->flags)) |
| 337 | goto node_error; |
| 338 | if (!test_bit(HFS_BNODE_NEW, &node->flags)) |
| 339 | return node; |
| 340 | |
| 341 | desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset); |
| 342 | node->prev = be32_to_cpu(desc->prev); |
| 343 | node->next = be32_to_cpu(desc->next); |
| 344 | node->num_recs = be16_to_cpu(desc->num_recs); |
| 345 | node->type = desc->type; |
| 346 | node->height = desc->height; |
| 347 | kunmap(node->page[0]); |
| 348 | |
| 349 | switch (node->type) { |
| 350 | case HFS_NODE_HEADER: |
| 351 | case HFS_NODE_MAP: |
| 352 | if (node->height != 0) |
| 353 | goto node_error; |
| 354 | break; |
| 355 | case HFS_NODE_LEAF: |
| 356 | if (node->height != 1) |
| 357 | goto node_error; |
| 358 | break; |
| 359 | case HFS_NODE_INDEX: |
| 360 | if (node->height <= 1 || node->height > tree->depth) |
| 361 | goto node_error; |
| 362 | break; |
| 363 | default: |
| 364 | goto node_error; |
| 365 | } |
| 366 | |
| 367 | rec_off = tree->node_size - 2; |
| 368 | off = hfs_bnode_read_u16(node, rec_off); |
| 369 | if (off != sizeof(struct hfs_bnode_desc)) |
| 370 | goto node_error; |
| 371 | for (i = 1; i <= node->num_recs; off = next_off, i++) { |
| 372 | rec_off -= 2; |
| 373 | next_off = hfs_bnode_read_u16(node, rec_off); |
| 374 | if (next_off <= off || |
| 375 | next_off > tree->node_size || |
| 376 | next_off & 1) |
| 377 | goto node_error; |
| 378 | entry_size = next_off - off; |
| 379 | if (node->type != HFS_NODE_INDEX && |
| 380 | node->type != HFS_NODE_LEAF) |
| 381 | continue; |
| 382 | key_size = hfs_bnode_read_u8(node, off) + 1; |
| 383 | if (key_size >= entry_size /*|| key_size & 1*/) |
| 384 | goto node_error; |
| 385 | } |
| 386 | clear_bit(HFS_BNODE_NEW, &node->flags); |
| 387 | wake_up(&node->lock_wq); |
| 388 | return node; |
| 389 | |
| 390 | node_error: |
| 391 | set_bit(HFS_BNODE_ERROR, &node->flags); |
| 392 | clear_bit(HFS_BNODE_NEW, &node->flags); |
| 393 | wake_up(&node->lock_wq); |
| 394 | hfs_bnode_put(node); |
| 395 | return ERR_PTR(-EIO); |
| 396 | } |
| 397 | |
| 398 | void hfs_bnode_free(struct hfs_bnode *node) |
| 399 | { |
| 400 | //int i; |
| 401 | |
| 402 | //for (i = 0; i < node->tree->pages_per_bnode; i++) |
| 403 | // if (node->page[i]) |
| 404 | // page_cache_release(node->page[i]); |
| 405 | kfree(node); |
| 406 | } |
| 407 | |
| 408 | struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num) |
| 409 | { |
| 410 | struct hfs_bnode *node; |
| 411 | struct page **pagep; |
| 412 | int i; |
| 413 | |
| 414 | spin_lock(&tree->hash_lock); |
| 415 | node = hfs_bnode_findhash(tree, num); |
| 416 | spin_unlock(&tree->hash_lock); |
Eric Sesterhenn | 4d4ef9a | 2006-03-26 18:26:51 +0200 | [diff] [blame] | 417 | BUG_ON(node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | node = __hfs_bnode_create(tree, num); |
| 419 | if (!node) |
| 420 | return ERR_PTR(-ENOMEM); |
| 421 | if (test_bit(HFS_BNODE_ERROR, &node->flags)) { |
| 422 | hfs_bnode_put(node); |
| 423 | return ERR_PTR(-EIO); |
| 424 | } |
| 425 | |
| 426 | pagep = node->page; |
| 427 | memset(kmap(*pagep) + node->page_offset, 0, |
| 428 | min((int)PAGE_CACHE_SIZE, (int)tree->node_size)); |
| 429 | set_page_dirty(*pagep); |
| 430 | kunmap(*pagep); |
| 431 | for (i = 1; i < tree->pages_per_bnode; i++) { |
| 432 | memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE); |
| 433 | set_page_dirty(*pagep); |
| 434 | kunmap(*pagep); |
| 435 | } |
| 436 | clear_bit(HFS_BNODE_NEW, &node->flags); |
| 437 | wake_up(&node->lock_wq); |
| 438 | |
| 439 | return node; |
| 440 | } |
| 441 | |
| 442 | void hfs_bnode_get(struct hfs_bnode *node) |
| 443 | { |
| 444 | if (node) { |
| 445 | atomic_inc(&node->refcnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n", |
| 447 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); |
| 448 | } |
| 449 | } |
| 450 | |
| 451 | /* Dispose of resources used by a node */ |
| 452 | void hfs_bnode_put(struct hfs_bnode *node) |
| 453 | { |
| 454 | if (node) { |
| 455 | struct hfs_btree *tree = node->tree; |
| 456 | int i; |
| 457 | |
| 458 | dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n", |
| 459 | node->tree->cnid, node->this, atomic_read(&node->refcnt)); |
Eric Sesterhenn | 4d4ef9a | 2006-03-26 18:26:51 +0200 | [diff] [blame] | 460 | BUG_ON(!atomic_read(&node->refcnt)); |
Roman Zippel | a5e3985 | 2005-09-06 15:18:47 -0700 | [diff] [blame] | 461 | if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | for (i = 0; i < tree->pages_per_bnode; i++) { |
Roman Zippel | 74f9c9c | 2005-08-01 21:11:41 -0700 | [diff] [blame] | 464 | if (!node->page[i]) |
| 465 | continue; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | mark_page_accessed(node->page[i]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | } |
| 468 | |
| 469 | if (test_bit(HFS_BNODE_DELETED, &node->flags)) { |
| 470 | hfs_bnode_unhash(node); |
| 471 | spin_unlock(&tree->hash_lock); |
| 472 | hfs_bmap_free(node); |
| 473 | hfs_bnode_free(node); |
| 474 | return; |
| 475 | } |
| 476 | spin_unlock(&tree->hash_lock); |
| 477 | } |
| 478 | } |