Commit | Line | Data |
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1da177e4 LT |
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++) { | |
74f9c9c2 RZ |
646 | if (!node->page[i]) |
647 | continue; | |
1da177e4 LT |
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 |