1 // SPDX-License-Identifier: GPL-2.0
3 * linux/fs/hfsplus/bnode.c
6 * Brad Boyer (flar@allandria.com)
7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
9 * Handle basic btree node operations
12 #include <linux/string.h>
13 #include <linux/slab.h>
14 #include <linux/pagemap.h>
16 #include <linux/swap.h>
18 #include "hfsplus_fs.h"
19 #include "hfsplus_raw.h"
21 /* Copy a specified range of bytes from the raw data of a node */
22 void hfs_bnode_read(struct hfs_bnode
*node
, void *buf
, int off
, int len
)
27 off
+= node
->page_offset
;
28 pagep
= node
->page
+ (off
>> PAGE_SHIFT
);
31 l
= min_t(int, len
, PAGE_SIZE
- off
);
32 memcpy_from_page(buf
, *pagep
, off
, l
);
34 while ((len
-= l
) != 0) {
36 l
= min_t(int, len
, PAGE_SIZE
);
37 memcpy_from_page(buf
, *++pagep
, 0, l
);
41 u16
hfs_bnode_read_u16(struct hfs_bnode
*node
, int off
)
44 /* TODO: optimize later... */
45 hfs_bnode_read(node
, &data
, off
, 2);
46 return be16_to_cpu(data
);
49 u8
hfs_bnode_read_u8(struct hfs_bnode
*node
, int off
)
52 /* TODO: optimize later... */
53 hfs_bnode_read(node
, &data
, off
, 1);
57 void hfs_bnode_read_key(struct hfs_bnode
*node
, void *key
, int off
)
59 struct hfs_btree
*tree
;
63 if (node
->type
== HFS_NODE_LEAF
||
64 tree
->attributes
& HFS_TREE_VARIDXKEYS
||
65 node
->tree
->cnid
== HFSPLUS_ATTR_CNID
)
66 key_len
= hfs_bnode_read_u16(node
, off
) + 2;
68 key_len
= tree
->max_key_len
+ 2;
70 hfs_bnode_read(node
, key
, off
, key_len
);
73 void hfs_bnode_write(struct hfs_bnode
*node
, void *buf
, int off
, int len
)
78 off
+= node
->page_offset
;
79 pagep
= node
->page
+ (off
>> PAGE_SHIFT
);
82 l
= min_t(int, len
, PAGE_SIZE
- off
);
83 memcpy_to_page(*pagep
, off
, buf
, l
);
84 set_page_dirty(*pagep
);
86 while ((len
-= l
) != 0) {
88 l
= min_t(int, len
, PAGE_SIZE
);
89 memcpy_to_page(*++pagep
, 0, buf
, l
);
90 set_page_dirty(*pagep
);
94 void hfs_bnode_write_u16(struct hfs_bnode
*node
, int off
, u16 data
)
96 __be16 v
= cpu_to_be16(data
);
97 /* TODO: optimize later... */
98 hfs_bnode_write(node
, &v
, off
, 2);
101 void hfs_bnode_clear(struct hfs_bnode
*node
, int off
, int len
)
106 off
+= node
->page_offset
;
107 pagep
= node
->page
+ (off
>> PAGE_SHIFT
);
110 l
= min_t(int, len
, PAGE_SIZE
- off
);
111 memzero_page(*pagep
, off
, l
);
112 set_page_dirty(*pagep
);
114 while ((len
-= l
) != 0) {
115 l
= min_t(int, len
, PAGE_SIZE
);
116 memzero_page(*++pagep
, 0, l
);
117 set_page_dirty(*pagep
);
121 void hfs_bnode_copy(struct hfs_bnode
*dst_node
, int dst
,
122 struct hfs_bnode
*src_node
, int src
, int len
)
124 struct page
**src_page
, **dst_page
;
127 hfs_dbg(BNODE_MOD
, "copybytes: %u,%u,%u\n", dst
, src
, len
);
130 src
+= src_node
->page_offset
;
131 dst
+= dst_node
->page_offset
;
132 src_page
= src_node
->page
+ (src
>> PAGE_SHIFT
);
134 dst_page
= dst_node
->page
+ (dst
>> PAGE_SHIFT
);
138 l
= min_t(int, len
, PAGE_SIZE
- src
);
139 memcpy_page(*dst_page
, src
, *src_page
, src
, l
);
140 set_page_dirty(*dst_page
);
142 while ((len
-= l
) != 0) {
143 l
= min_t(int, len
, PAGE_SIZE
);
144 memcpy_page(*++dst_page
, 0, *++src_page
, 0, l
);
145 set_page_dirty(*dst_page
);
148 void *src_ptr
, *dst_ptr
;
151 dst_ptr
= kmap_local_page(*dst_page
) + dst
;
152 src_ptr
= kmap_local_page(*src_page
) + src
;
153 if (PAGE_SIZE
- src
< PAGE_SIZE
- dst
) {
163 memcpy(dst_ptr
, src_ptr
, l
);
164 kunmap_local(src_ptr
);
165 set_page_dirty(*dst_page
);
166 kunmap_local(dst_ptr
);
171 } while ((len
-= l
));
175 void hfs_bnode_move(struct hfs_bnode
*node
, int dst
, int src
, int len
)
177 struct page
**src_page
, **dst_page
;
178 void *src_ptr
, *dst_ptr
;
181 hfs_dbg(BNODE_MOD
, "movebytes: %u,%u,%u\n", dst
, src
, len
);
184 src
+= node
->page_offset
;
185 dst
+= node
->page_offset
;
188 src_page
= node
->page
+ (src
>> PAGE_SHIFT
);
189 src
= (src
& ~PAGE_MASK
) + 1;
191 dst_page
= node
->page
+ (dst
>> PAGE_SHIFT
);
192 dst
= (dst
& ~PAGE_MASK
) + 1;
196 dst_ptr
= kmap_local_page(*dst_page
);
197 src_ptr
= kmap_local_page(*src_page
);
198 memmove(dst_ptr
, src_ptr
, src
);
199 kunmap_local(src_ptr
);
200 set_page_dirty(*dst_page
);
201 kunmap_local(dst_ptr
);
208 dst_ptr
= kmap_local_page(*dst_page
);
209 src_ptr
= kmap_local_page(*src_page
);
210 memmove(dst_ptr
+ src
, src_ptr
+ src
, len
);
211 kunmap_local(src_ptr
);
212 set_page_dirty(*dst_page
);
213 kunmap_local(dst_ptr
);
216 dst_ptr
= kmap_local_page(*dst_page
) + dst
;
217 src_ptr
= kmap_local_page(*src_page
) + src
;
228 memmove(dst_ptr
- l
, src_ptr
- l
, l
);
229 kunmap_local(src_ptr
);
230 set_page_dirty(*dst_page
);
231 kunmap_local(dst_ptr
);
232 if (dst
== PAGE_SIZE
)
236 } while ((len
-= l
));
239 src_page
= node
->page
+ (src
>> PAGE_SHIFT
);
241 dst_page
= node
->page
+ (dst
>> PAGE_SHIFT
);
245 l
= min_t(int, len
, PAGE_SIZE
- src
);
247 dst_ptr
= kmap_local_page(*dst_page
) + src
;
248 src_ptr
= kmap_local_page(*src_page
) + src
;
249 memmove(dst_ptr
, src_ptr
, l
);
250 kunmap_local(src_ptr
);
251 set_page_dirty(*dst_page
);
252 kunmap_local(dst_ptr
);
254 while ((len
-= l
) != 0) {
255 l
= min_t(int, len
, PAGE_SIZE
);
256 dst_ptr
= kmap_local_page(*++dst_page
);
257 src_ptr
= kmap_local_page(*++src_page
);
258 memmove(dst_ptr
, src_ptr
, l
);
259 kunmap_local(src_ptr
);
260 set_page_dirty(*dst_page
);
261 kunmap_local(dst_ptr
);
265 dst_ptr
= kmap_local_page(*dst_page
) + dst
;
266 src_ptr
= kmap_local_page(*src_page
) + src
;
267 if (PAGE_SIZE
- src
<
278 memmove(dst_ptr
, src_ptr
, l
);
279 kunmap_local(src_ptr
);
280 set_page_dirty(*dst_page
);
281 kunmap_local(dst_ptr
);
286 } while ((len
-= l
));
291 void hfs_bnode_dump(struct hfs_bnode
*node
)
293 struct hfs_bnode_desc desc
;
297 hfs_dbg(BNODE_MOD
, "bnode: %d\n", node
->this);
298 hfs_bnode_read(node
, &desc
, 0, sizeof(desc
));
299 hfs_dbg(BNODE_MOD
, "%d, %d, %d, %d, %d\n",
300 be32_to_cpu(desc
.next
), be32_to_cpu(desc
.prev
),
301 desc
.type
, desc
.height
, be16_to_cpu(desc
.num_recs
));
303 off
= node
->tree
->node_size
- 2;
304 for (i
= be16_to_cpu(desc
.num_recs
); i
>= 0; off
-= 2, i
--) {
305 key_off
= hfs_bnode_read_u16(node
, off
);
306 hfs_dbg(BNODE_MOD
, " %d", key_off
);
307 if (i
&& node
->type
== HFS_NODE_INDEX
) {
310 if (node
->tree
->attributes
& HFS_TREE_VARIDXKEYS
||
311 node
->tree
->cnid
== HFSPLUS_ATTR_CNID
)
312 tmp
= hfs_bnode_read_u16(node
, key_off
) + 2;
314 tmp
= node
->tree
->max_key_len
+ 2;
315 hfs_dbg_cont(BNODE_MOD
, " (%d", tmp
);
316 hfs_bnode_read(node
, &cnid
, key_off
+ tmp
, 4);
317 hfs_dbg_cont(BNODE_MOD
, ",%d)", be32_to_cpu(cnid
));
318 } else if (i
&& node
->type
== HFS_NODE_LEAF
) {
321 tmp
= hfs_bnode_read_u16(node
, key_off
);
322 hfs_dbg_cont(BNODE_MOD
, " (%d)", tmp
);
325 hfs_dbg_cont(BNODE_MOD
, "\n");
328 void hfs_bnode_unlink(struct hfs_bnode
*node
)
330 struct hfs_btree
*tree
;
331 struct hfs_bnode
*tmp
;
336 tmp
= hfs_bnode_find(tree
, node
->prev
);
339 tmp
->next
= node
->next
;
340 cnid
= cpu_to_be32(tmp
->next
);
341 hfs_bnode_write(tmp
, &cnid
,
342 offsetof(struct hfs_bnode_desc
, next
), 4);
344 } else if (node
->type
== HFS_NODE_LEAF
)
345 tree
->leaf_head
= node
->next
;
348 tmp
= hfs_bnode_find(tree
, node
->next
);
351 tmp
->prev
= node
->prev
;
352 cnid
= cpu_to_be32(tmp
->prev
);
353 hfs_bnode_write(tmp
, &cnid
,
354 offsetof(struct hfs_bnode_desc
, prev
), 4);
356 } else if (node
->type
== HFS_NODE_LEAF
)
357 tree
->leaf_tail
= node
->prev
;
360 if (!node
->prev
&& !node
->next
)
361 hfs_dbg(BNODE_MOD
, "hfs_btree_del_level\n");
366 set_bit(HFS_BNODE_DELETED
, &node
->flags
);
369 static inline int hfs_bnode_hash(u32 num
)
371 num
= (num
>> 16) + num
;
373 return num
& (NODE_HASH_SIZE
- 1);
376 struct hfs_bnode
*hfs_bnode_findhash(struct hfs_btree
*tree
, u32 cnid
)
378 struct hfs_bnode
*node
;
380 if (cnid
>= tree
->node_count
) {
381 pr_err("request for non-existent node %d in B*Tree\n",
386 for (node
= tree
->node_hash
[hfs_bnode_hash(cnid
)];
387 node
; node
= node
->next_hash
)
388 if (node
->this == cnid
)
393 static struct hfs_bnode
*__hfs_bnode_create(struct hfs_btree
*tree
, u32 cnid
)
395 struct hfs_bnode
*node
, *node2
;
396 struct address_space
*mapping
;
398 int size
, block
, i
, hash
;
401 if (cnid
>= tree
->node_count
) {
402 pr_err("request for non-existent node %d in B*Tree\n",
407 size
= sizeof(struct hfs_bnode
) + tree
->pages_per_bnode
*
408 sizeof(struct page
*);
409 node
= kzalloc(size
, GFP_KERNEL
);
414 set_bit(HFS_BNODE_NEW
, &node
->flags
);
415 atomic_set(&node
->refcnt
, 1);
416 hfs_dbg(BNODE_REFS
, "new_node(%d:%d): 1\n",
417 node
->tree
->cnid
, node
->this);
418 init_waitqueue_head(&node
->lock_wq
);
419 spin_lock(&tree
->hash_lock
);
420 node2
= hfs_bnode_findhash(tree
, cnid
);
422 hash
= hfs_bnode_hash(cnid
);
423 node
->next_hash
= tree
->node_hash
[hash
];
424 tree
->node_hash
[hash
] = node
;
425 tree
->node_hash_cnt
++;
427 spin_unlock(&tree
->hash_lock
);
429 wait_event(node2
->lock_wq
,
430 !test_bit(HFS_BNODE_NEW
, &node2
->flags
));
433 spin_unlock(&tree
->hash_lock
);
435 mapping
= tree
->inode
->i_mapping
;
436 off
= (loff_t
)cnid
<< tree
->node_size_shift
;
437 block
= off
>> PAGE_SHIFT
;
438 node
->page_offset
= off
& ~PAGE_MASK
;
439 for (i
= 0; i
< tree
->pages_per_bnode
; block
++, i
++) {
440 page
= read_mapping_page(mapping
, block
, NULL
);
443 node
->page
[i
] = page
;
448 set_bit(HFS_BNODE_ERROR
, &node
->flags
);
452 void hfs_bnode_unhash(struct hfs_bnode
*node
)
454 struct hfs_bnode
**p
;
456 hfs_dbg(BNODE_REFS
, "remove_node(%d:%d): %d\n",
457 node
->tree
->cnid
, node
->this, atomic_read(&node
->refcnt
));
458 for (p
= &node
->tree
->node_hash
[hfs_bnode_hash(node
->this)];
459 *p
&& *p
!= node
; p
= &(*p
)->next_hash
)
462 *p
= node
->next_hash
;
463 node
->tree
->node_hash_cnt
--;
466 /* Load a particular node out of a tree */
467 struct hfs_bnode
*hfs_bnode_find(struct hfs_btree
*tree
, u32 num
)
469 struct hfs_bnode
*node
;
470 struct hfs_bnode_desc
*desc
;
471 int i
, rec_off
, off
, next_off
;
472 int entry_size
, key_size
;
474 spin_lock(&tree
->hash_lock
);
475 node
= hfs_bnode_findhash(tree
, num
);
478 spin_unlock(&tree
->hash_lock
);
479 wait_event(node
->lock_wq
,
480 !test_bit(HFS_BNODE_NEW
, &node
->flags
));
481 if (test_bit(HFS_BNODE_ERROR
, &node
->flags
))
485 spin_unlock(&tree
->hash_lock
);
486 node
= __hfs_bnode_create(tree
, num
);
488 return ERR_PTR(-ENOMEM
);
489 if (test_bit(HFS_BNODE_ERROR
, &node
->flags
))
491 if (!test_bit(HFS_BNODE_NEW
, &node
->flags
))
494 desc
= (struct hfs_bnode_desc
*)(kmap_local_page(node
->page
[0]) +
496 node
->prev
= be32_to_cpu(desc
->prev
);
497 node
->next
= be32_to_cpu(desc
->next
);
498 node
->num_recs
= be16_to_cpu(desc
->num_recs
);
499 node
->type
= desc
->type
;
500 node
->height
= desc
->height
;
503 switch (node
->type
) {
504 case HFS_NODE_HEADER
:
506 if (node
->height
!= 0)
510 if (node
->height
!= 1)
514 if (node
->height
<= 1 || node
->height
> tree
->depth
)
521 rec_off
= tree
->node_size
- 2;
522 off
= hfs_bnode_read_u16(node
, rec_off
);
523 if (off
!= sizeof(struct hfs_bnode_desc
))
525 for (i
= 1; i
<= node
->num_recs
; off
= next_off
, i
++) {
527 next_off
= hfs_bnode_read_u16(node
, rec_off
);
528 if (next_off
<= off
||
529 next_off
> tree
->node_size
||
532 entry_size
= next_off
- off
;
533 if (node
->type
!= HFS_NODE_INDEX
&&
534 node
->type
!= HFS_NODE_LEAF
)
536 key_size
= hfs_bnode_read_u16(node
, off
) + 2;
537 if (key_size
>= entry_size
|| key_size
& 1)
540 clear_bit(HFS_BNODE_NEW
, &node
->flags
);
541 wake_up(&node
->lock_wq
);
545 set_bit(HFS_BNODE_ERROR
, &node
->flags
);
546 clear_bit(HFS_BNODE_NEW
, &node
->flags
);
547 wake_up(&node
->lock_wq
);
549 return ERR_PTR(-EIO
);
552 void hfs_bnode_free(struct hfs_bnode
*node
)
556 for (i
= 0; i
< node
->tree
->pages_per_bnode
; i
++)
558 put_page(node
->page
[i
]);
562 struct hfs_bnode
*hfs_bnode_create(struct hfs_btree
*tree
, u32 num
)
564 struct hfs_bnode
*node
;
568 spin_lock(&tree
->hash_lock
);
569 node
= hfs_bnode_findhash(tree
, num
);
570 spin_unlock(&tree
->hash_lock
);
572 pr_crit("new node %u already hashed?\n", num
);
576 node
= __hfs_bnode_create(tree
, num
);
578 return ERR_PTR(-ENOMEM
);
579 if (test_bit(HFS_BNODE_ERROR
, &node
->flags
)) {
581 return ERR_PTR(-EIO
);
585 memzero_page(*pagep
, node
->page_offset
,
586 min_t(int, PAGE_SIZE
, tree
->node_size
));
587 set_page_dirty(*pagep
);
588 for (i
= 1; i
< tree
->pages_per_bnode
; i
++) {
589 memzero_page(*++pagep
, 0, PAGE_SIZE
);
590 set_page_dirty(*pagep
);
592 clear_bit(HFS_BNODE_NEW
, &node
->flags
);
593 wake_up(&node
->lock_wq
);
598 void hfs_bnode_get(struct hfs_bnode
*node
)
601 atomic_inc(&node
->refcnt
);
602 hfs_dbg(BNODE_REFS
, "get_node(%d:%d): %d\n",
603 node
->tree
->cnid
, node
->this,
604 atomic_read(&node
->refcnt
));
608 /* Dispose of resources used by a node */
609 void hfs_bnode_put(struct hfs_bnode
*node
)
612 struct hfs_btree
*tree
= node
->tree
;
615 hfs_dbg(BNODE_REFS
, "put_node(%d:%d): %d\n",
616 node
->tree
->cnid
, node
->this,
617 atomic_read(&node
->refcnt
));
618 BUG_ON(!atomic_read(&node
->refcnt
));
619 if (!atomic_dec_and_lock(&node
->refcnt
, &tree
->hash_lock
))
621 for (i
= 0; i
< tree
->pages_per_bnode
; i
++) {
624 mark_page_accessed(node
->page
[i
]);
627 if (test_bit(HFS_BNODE_DELETED
, &node
->flags
)) {
628 hfs_bnode_unhash(node
);
629 spin_unlock(&tree
->hash_lock
);
630 if (hfs_bnode_need_zeroout(tree
))
631 hfs_bnode_clear(node
, 0, tree
->node_size
);
633 hfs_bnode_free(node
);
636 spin_unlock(&tree
->hash_lock
);
641 * Unused nodes have to be zeroed if this is the catalog tree and
642 * a corresponding flag in the volume header is set.
644 bool hfs_bnode_need_zeroout(struct hfs_btree
*tree
)
646 struct super_block
*sb
= tree
->inode
->i_sb
;
647 struct hfsplus_sb_info
*sbi
= HFSPLUS_SB(sb
);
648 const u32 volume_attr
= be32_to_cpu(sbi
->s_vhdr
->attributes
);
650 return tree
->cnid
== HFSPLUS_CAT_CNID
&&
651 volume_attr
& HFSPLUS_VOL_UNUSED_NODE_FIX
;