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