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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/hfsplus/bnode.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/hfsplus/bnode.c')
-rw-r--r--fs/hfsplus/bnode.c662
1 files changed, 662 insertions, 0 deletions
diff --git a/fs/hfsplus/bnode.c b/fs/hfsplus/bnode.c
new file mode 100644
index 000000000000..267872e84d71
--- /dev/null
+++ b/fs/hfsplus/bnode.c
@@ -0,0 +1,662 @@
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 */
24void 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
45u16 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
53u8 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
61void 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
76void 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
99void 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
106void 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
128void 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
188void 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
297void 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
333void 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
373static 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
380struct 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
398static 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;
460fail:
461 set_bit(HFS_BNODE_ERROR, &node->flags);
462 return node;
463}
464
465void 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 */
481struct 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
556node_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
564void 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
574struct 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
611void 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 */
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, 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++) {
646 mark_page_accessed(node->page[i]);
647#if REF_PAGES
648 put_page(node->page[i]);
649#endif
650 }
651
652 if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
653 hfs_bnode_unhash(node);
654 spin_unlock(&tree->hash_lock);
655 hfs_bmap_free(node);
656 hfs_bnode_free(node);
657 return;
658 }
659 spin_unlock(&tree->hash_lock);
660 }
661}
662
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