Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[platform/kernel/linux-rpi.git] / fs / hfsplus / bnode.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/hfsplus/bnode.c
4  *
5  * Copyright (C) 2001
6  * Brad Boyer (flar@allandria.com)
7  * (C) 2003 Ardis Technologies <roman@ardistech.com>
8  *
9  * Handle basic btree node operations
10  */
11
12 #include <linux/string.h>
13 #include <linux/slab.h>
14 #include <linux/pagemap.h>
15 #include <linux/fs.h>
16 #include <linux/swap.h>
17
18 #include "hfsplus_fs.h"
19 #include "hfsplus_raw.h"
20
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)
23 {
24         struct page **pagep;
25         int l;
26
27         off += node->page_offset;
28         pagep = node->page + (off >> PAGE_SHIFT);
29         off &= ~PAGE_MASK;
30
31         l = min_t(int, len, PAGE_SIZE - off);
32         memcpy_from_page(buf, *pagep, off, l);
33
34         while ((len -= l) != 0) {
35                 buf += l;
36                 l = min_t(int, len, PAGE_SIZE);
37                 memcpy_from_page(buf, *++pagep, 0, l);
38         }
39 }
40
41 u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
42 {
43         __be16 data;
44         /* TODO: optimize later... */
45         hfs_bnode_read(node, &data, off, 2);
46         return be16_to_cpu(data);
47 }
48
49 u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
50 {
51         u8 data;
52         /* TODO: optimize later... */
53         hfs_bnode_read(node, &data, off, 1);
54         return data;
55 }
56
57 void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
58 {
59         struct hfs_btree *tree;
60         int key_len;
61
62         tree = node->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;
67         else
68                 key_len = tree->max_key_len + 2;
69
70         hfs_bnode_read(node, key, off, key_len);
71 }
72
73 void 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_SHIFT);
80         off &= ~PAGE_MASK;
81
82         l = min_t(int, len, PAGE_SIZE - off);
83         memcpy_to_page(*pagep, off, buf, l);
84         set_page_dirty(*pagep);
85
86         while ((len -= l) != 0) {
87                 buf += l;
88                 l = min_t(int, len, PAGE_SIZE);
89                 memcpy_to_page(*++pagep, 0, buf, l);
90                 set_page_dirty(*pagep);
91         }
92 }
93
94 void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
95 {
96         __be16 v = cpu_to_be16(data);
97         /* TODO: optimize later... */
98         hfs_bnode_write(node, &v, off, 2);
99 }
100
101 void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
102 {
103         struct page **pagep;
104         int l;
105
106         off += node->page_offset;
107         pagep = node->page + (off >> PAGE_SHIFT);
108         off &= ~PAGE_MASK;
109
110         l = min_t(int, len, PAGE_SIZE - off);
111         memzero_page(*pagep, off, l);
112         set_page_dirty(*pagep);
113
114         while ((len -= l) != 0) {
115                 l = min_t(int, len, PAGE_SIZE);
116                 memzero_page(*++pagep, 0, l);
117                 set_page_dirty(*pagep);
118         }
119 }
120
121 void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
122                     struct hfs_bnode *src_node, int src, int len)
123 {
124         struct page **src_page, **dst_page;
125         int l;
126
127         hfs_dbg(BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
128         if (!len)
129                 return;
130         src += src_node->page_offset;
131         dst += dst_node->page_offset;
132         src_page = src_node->page + (src >> PAGE_SHIFT);
133         src &= ~PAGE_MASK;
134         dst_page = dst_node->page + (dst >> PAGE_SHIFT);
135         dst &= ~PAGE_MASK;
136
137         if (src == dst) {
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);
141
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);
146                 }
147         } else {
148                 void *src_ptr, *dst_ptr;
149
150                 do {
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) {
154                                 l = PAGE_SIZE - src;
155                                 src = 0;
156                                 dst += l;
157                         } else {
158                                 l = PAGE_SIZE - dst;
159                                 src += l;
160                                 dst = 0;
161                         }
162                         l = min(len, l);
163                         memcpy(dst_ptr, src_ptr, l);
164                         kunmap_local(src_ptr);
165                         set_page_dirty(*dst_page);
166                         kunmap_local(dst_ptr);
167                         if (!dst)
168                                 dst_page++;
169                         else
170                                 src_page++;
171                 } while ((len -= l));
172         }
173 }
174
175 void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
176 {
177         struct page **src_page, **dst_page;
178         void *src_ptr, *dst_ptr;
179         int l;
180
181         hfs_dbg(BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
182         if (!len)
183                 return;
184         src += node->page_offset;
185         dst += node->page_offset;
186         if (dst > src) {
187                 src += len - 1;
188                 src_page = node->page + (src >> PAGE_SHIFT);
189                 src = (src & ~PAGE_MASK) + 1;
190                 dst += len - 1;
191                 dst_page = node->page + (dst >> PAGE_SHIFT);
192                 dst = (dst & ~PAGE_MASK) + 1;
193
194                 if (src == dst) {
195                         while (src < len) {
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);
202                                 len -= src;
203                                 src = PAGE_SIZE;
204                                 src_page--;
205                                 dst_page--;
206                         }
207                         src -= len;
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);
214                 } else {
215                         do {
216                                 dst_ptr = kmap_local_page(*dst_page) + dst;
217                                 src_ptr = kmap_local_page(*src_page) + src;
218                                 if (src < dst) {
219                                         l = src;
220                                         src = PAGE_SIZE;
221                                         dst -= l;
222                                 } else {
223                                         l = dst;
224                                         src -= l;
225                                         dst = PAGE_SIZE;
226                                 }
227                                 l = min(len, l);
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)
233                                         dst_page--;
234                                 else
235                                         src_page--;
236                         } while ((len -= l));
237                 }
238         } else {
239                 src_page = node->page + (src >> PAGE_SHIFT);
240                 src &= ~PAGE_MASK;
241                 dst_page = node->page + (dst >> PAGE_SHIFT);
242                 dst &= ~PAGE_MASK;
243
244                 if (src == dst) {
245                         l = min_t(int, len, PAGE_SIZE - src);
246
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);
253
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);
262                         }
263                 } else {
264                         do {
265                                 dst_ptr = kmap_local_page(*dst_page) + dst;
266                                 src_ptr = kmap_local_page(*src_page) + src;
267                                 if (PAGE_SIZE - src <
268                                                 PAGE_SIZE - dst) {
269                                         l = PAGE_SIZE - src;
270                                         src = 0;
271                                         dst += l;
272                                 } else {
273                                         l = PAGE_SIZE - dst;
274                                         src += l;
275                                         dst = 0;
276                                 }
277                                 l = min(len, l);
278                                 memmove(dst_ptr, src_ptr, l);
279                                 kunmap_local(src_ptr);
280                                 set_page_dirty(*dst_page);
281                                 kunmap_local(dst_ptr);
282                                 if (!dst)
283                                         dst_page++;
284                                 else
285                                         src_page++;
286                         } while ((len -= l));
287                 }
288         }
289 }
290
291 void hfs_bnode_dump(struct hfs_bnode *node)
292 {
293         struct hfs_bnode_desc desc;
294         __be32 cnid;
295         int i, off, key_off;
296
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));
302
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) {
308                         int tmp;
309
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;
313                         else
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) {
319                         int tmp;
320
321                         tmp = hfs_bnode_read_u16(node, key_off);
322                         hfs_dbg_cont(BNODE_MOD, " (%d)", tmp);
323                 }
324         }
325         hfs_dbg_cont(BNODE_MOD, "\n");
326 }
327
328 void hfs_bnode_unlink(struct hfs_bnode *node)
329 {
330         struct hfs_btree *tree;
331         struct hfs_bnode *tmp;
332         __be32 cnid;
333
334         tree = node->tree;
335         if (node->prev) {
336                 tmp = hfs_bnode_find(tree, node->prev);
337                 if (IS_ERR(tmp))
338                         return;
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);
343                 hfs_bnode_put(tmp);
344         } else if (node->type == HFS_NODE_LEAF)
345                 tree->leaf_head = node->next;
346
347         if (node->next) {
348                 tmp = hfs_bnode_find(tree, node->next);
349                 if (IS_ERR(tmp))
350                         return;
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);
355                 hfs_bnode_put(tmp);
356         } else if (node->type == HFS_NODE_LEAF)
357                 tree->leaf_tail = node->prev;
358
359         /* move down? */
360         if (!node->prev && !node->next)
361                 hfs_dbg(BNODE_MOD, "hfs_btree_del_level\n");
362         if (!node->parent) {
363                 tree->root = 0;
364                 tree->depth = 0;
365         }
366         set_bit(HFS_BNODE_DELETED, &node->flags);
367 }
368
369 static inline int hfs_bnode_hash(u32 num)
370 {
371         num = (num >> 16) + num;
372         num += num >> 8;
373         return num & (NODE_HASH_SIZE - 1);
374 }
375
376 struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
377 {
378         struct hfs_bnode *node;
379
380         if (cnid >= tree->node_count) {
381                 pr_err("request for non-existent node %d in B*Tree\n",
382                        cnid);
383                 return NULL;
384         }
385
386         for (node = tree->node_hash[hfs_bnode_hash(cnid)];
387                         node; node = node->next_hash)
388                 if (node->this == cnid)
389                         return node;
390         return NULL;
391 }
392
393 static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
394 {
395         struct hfs_bnode *node, *node2;
396         struct address_space *mapping;
397         struct page *page;
398         int size, block, i, hash;
399         loff_t off;
400
401         if (cnid >= tree->node_count) {
402                 pr_err("request for non-existent node %d in B*Tree\n",
403                        cnid);
404                 return NULL;
405         }
406
407         size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
408                 sizeof(struct page *);
409         node = kzalloc(size, GFP_KERNEL);
410         if (!node)
411                 return NULL;
412         node->tree = tree;
413         node->this = cnid;
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);
421         if (!node2) {
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++;
426         } else {
427                 spin_unlock(&tree->hash_lock);
428                 kfree(node);
429                 wait_event(node2->lock_wq,
430                         !test_bit(HFS_BNODE_NEW, &node2->flags));
431                 return node2;
432         }
433         spin_unlock(&tree->hash_lock);
434
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);
441                 if (IS_ERR(page))
442                         goto fail;
443                 node->page[i] = page;
444         }
445
446         return node;
447 fail:
448         set_bit(HFS_BNODE_ERROR, &node->flags);
449         return node;
450 }
451
452 void hfs_bnode_unhash(struct hfs_bnode *node)
453 {
454         struct hfs_bnode **p;
455
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)
460                 ;
461         BUG_ON(!*p);
462         *p = node->next_hash;
463         node->tree->node_hash_cnt--;
464 }
465
466 /* Load a particular node out of a tree */
467 struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
468 {
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;
473
474         spin_lock(&tree->hash_lock);
475         node = hfs_bnode_findhash(tree, num);
476         if (node) {
477                 hfs_bnode_get(node);
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))
482                         goto node_error;
483                 return node;
484         }
485         spin_unlock(&tree->hash_lock);
486         node = __hfs_bnode_create(tree, num);
487         if (!node)
488                 return ERR_PTR(-ENOMEM);
489         if (test_bit(HFS_BNODE_ERROR, &node->flags))
490                 goto node_error;
491         if (!test_bit(HFS_BNODE_NEW, &node->flags))
492                 return node;
493
494         desc = (struct hfs_bnode_desc *)(kmap_local_page(node->page[0]) +
495                                                          node->page_offset);
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;
501         kunmap_local(desc);
502
503         switch (node->type) {
504         case HFS_NODE_HEADER:
505         case HFS_NODE_MAP:
506                 if (node->height != 0)
507                         goto node_error;
508                 break;
509         case HFS_NODE_LEAF:
510                 if (node->height != 1)
511                         goto node_error;
512                 break;
513         case HFS_NODE_INDEX:
514                 if (node->height <= 1 || node->height > tree->depth)
515                         goto node_error;
516                 break;
517         default:
518                 goto node_error;
519         }
520
521         rec_off = tree->node_size - 2;
522         off = hfs_bnode_read_u16(node, rec_off);
523         if (off != sizeof(struct hfs_bnode_desc))
524                 goto node_error;
525         for (i = 1; i <= node->num_recs; off = next_off, i++) {
526                 rec_off -= 2;
527                 next_off = hfs_bnode_read_u16(node, rec_off);
528                 if (next_off <= off ||
529                     next_off > tree->node_size ||
530                     next_off & 1)
531                         goto node_error;
532                 entry_size = next_off - off;
533                 if (node->type != HFS_NODE_INDEX &&
534                     node->type != HFS_NODE_LEAF)
535                         continue;
536                 key_size = hfs_bnode_read_u16(node, off) + 2;
537                 if (key_size >= entry_size || key_size & 1)
538                         goto node_error;
539         }
540         clear_bit(HFS_BNODE_NEW, &node->flags);
541         wake_up(&node->lock_wq);
542         return node;
543
544 node_error:
545         set_bit(HFS_BNODE_ERROR, &node->flags);
546         clear_bit(HFS_BNODE_NEW, &node->flags);
547         wake_up(&node->lock_wq);
548         hfs_bnode_put(node);
549         return ERR_PTR(-EIO);
550 }
551
552 void hfs_bnode_free(struct hfs_bnode *node)
553 {
554         int i;
555
556         for (i = 0; i < node->tree->pages_per_bnode; i++)
557                 if (node->page[i])
558                         put_page(node->page[i]);
559         kfree(node);
560 }
561
562 struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
563 {
564         struct hfs_bnode *node;
565         struct page **pagep;
566         int i;
567
568         spin_lock(&tree->hash_lock);
569         node = hfs_bnode_findhash(tree, num);
570         spin_unlock(&tree->hash_lock);
571         if (node) {
572                 pr_crit("new node %u already hashed?\n", num);
573                 WARN_ON(1);
574                 return node;
575         }
576         node = __hfs_bnode_create(tree, num);
577         if (!node)
578                 return ERR_PTR(-ENOMEM);
579         if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
580                 hfs_bnode_put(node);
581                 return ERR_PTR(-EIO);
582         }
583
584         pagep = node->page;
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);
591         }
592         clear_bit(HFS_BNODE_NEW, &node->flags);
593         wake_up(&node->lock_wq);
594
595         return node;
596 }
597
598 void hfs_bnode_get(struct hfs_bnode *node)
599 {
600         if (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));
605         }
606 }
607
608 /* Dispose of resources used by a node */
609 void hfs_bnode_put(struct hfs_bnode *node)
610 {
611         if (node) {
612                 struct hfs_btree *tree = node->tree;
613                 int i;
614
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))
620                         return;
621                 for (i = 0; i < tree->pages_per_bnode; i++) {
622                         if (!node->page[i])
623                                 continue;
624                         mark_page_accessed(node->page[i]);
625                 }
626
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);
632                         hfs_bmap_free(node);
633                         hfs_bnode_free(node);
634                         return;
635                 }
636                 spin_unlock(&tree->hash_lock);
637         }
638 }
639
640 /*
641  * Unused nodes have to be zeroed if this is the catalog tree and
642  * a corresponding flag in the volume header is set.
643  */
644 bool hfs_bnode_need_zeroout(struct hfs_btree *tree)
645 {
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);
649
650         return tree->cnid == HFSPLUS_CAT_CNID &&
651                 volume_attr & HFSPLUS_VOL_UNUSED_NODE_FIX;
652 }