~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/hfs/bnode.c

Version: ~ [ linux-5.2 ] ~ [ linux-5.1.16 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.57 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.132 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.184 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.184 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.69 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  *  linux/fs/hfs/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/pagemap.h>
 12 #include <linux/slab.h>
 13 #include <linux/swap.h>
 14 
 15 #include "btree.h"
 16 
 17 void hfs_bnode_read(struct hfs_bnode *node, void *buf,
 18                 int off, int len)
 19 {
 20         struct page *page;
 21 
 22         off += node->page_offset;
 23         page = node->page[0];
 24 
 25         memcpy(buf, kmap(page) + off, len);
 26         kunmap(page);
 27 }
 28 
 29 u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
 30 {
 31         __be16 data;
 32         // optimize later...
 33         hfs_bnode_read(node, &data, off, 2);
 34         return be16_to_cpu(data);
 35 }
 36 
 37 u8 hfs_bnode_read_u8(struct hfs_bnode *node, int off)
 38 {
 39         u8 data;
 40         // optimize later...
 41         hfs_bnode_read(node, &data, off, 1);
 42         return data;
 43 }
 44 
 45 void hfs_bnode_read_key(struct hfs_bnode *node, void *key, int off)
 46 {
 47         struct hfs_btree *tree;
 48         int key_len;
 49 
 50         tree = node->tree;
 51         if (node->type == HFS_NODE_LEAF ||
 52             tree->attributes & HFS_TREE_VARIDXKEYS)
 53                 key_len = hfs_bnode_read_u8(node, off) + 1;
 54         else
 55                 key_len = tree->max_key_len + 1;
 56 
 57         hfs_bnode_read(node, key, off, key_len);
 58 }
 59 
 60 void hfs_bnode_write(struct hfs_bnode *node, void *buf, int off, int len)
 61 {
 62         struct page *page;
 63 
 64         off += node->page_offset;
 65         page = node->page[0];
 66 
 67         memcpy(kmap(page) + off, buf, len);
 68         kunmap(page);
 69         set_page_dirty(page);
 70 }
 71 
 72 void hfs_bnode_write_u16(struct hfs_bnode *node, int off, u16 data)
 73 {
 74         __be16 v = cpu_to_be16(data);
 75         // optimize later...
 76         hfs_bnode_write(node, &v, off, 2);
 77 }
 78 
 79 void hfs_bnode_write_u8(struct hfs_bnode *node, int off, u8 data)
 80 {
 81         // optimize later...
 82         hfs_bnode_write(node, &data, off, 1);
 83 }
 84 
 85 void hfs_bnode_clear(struct hfs_bnode *node, int off, int len)
 86 {
 87         struct page *page;
 88 
 89         off += node->page_offset;
 90         page = node->page[0];
 91 
 92         memset(kmap(page) + off, 0, len);
 93         kunmap(page);
 94         set_page_dirty(page);
 95 }
 96 
 97 void hfs_bnode_copy(struct hfs_bnode *dst_node, int dst,
 98                 struct hfs_bnode *src_node, int src, int len)
 99 {
100         struct hfs_btree *tree;
101         struct page *src_page, *dst_page;
102 
103         dprint(DBG_BNODE_MOD, "copybytes: %u,%u,%u\n", dst, src, len);
104         if (!len)
105                 return;
106         tree = src_node->tree;
107         src += src_node->page_offset;
108         dst += dst_node->page_offset;
109         src_page = src_node->page[0];
110         dst_page = dst_node->page[0];
111 
112         memcpy(kmap(dst_page) + dst, kmap(src_page) + src, len);
113         kunmap(src_page);
114         kunmap(dst_page);
115         set_page_dirty(dst_page);
116 }
117 
118 void hfs_bnode_move(struct hfs_bnode *node, int dst, int src, int len)
119 {
120         struct page *page;
121         void *ptr;
122 
123         dprint(DBG_BNODE_MOD, "movebytes: %u,%u,%u\n", dst, src, len);
124         if (!len)
125                 return;
126         src += node->page_offset;
127         dst += node->page_offset;
128         page = node->page[0];
129         ptr = kmap(page);
130         memmove(ptr + dst, ptr + src, len);
131         kunmap(page);
132         set_page_dirty(page);
133 }
134 
135 void hfs_bnode_dump(struct hfs_bnode *node)
136 {
137         struct hfs_bnode_desc desc;
138         __be32 cnid;
139         int i, off, key_off;
140 
141         dprint(DBG_BNODE_MOD, "bnode: %d\n", node->this);
142         hfs_bnode_read(node, &desc, 0, sizeof(desc));
143         dprint(DBG_BNODE_MOD, "%d, %d, %d, %d, %d\n",
144                 be32_to_cpu(desc.next), be32_to_cpu(desc.prev),
145                 desc.type, desc.height, be16_to_cpu(desc.num_recs));
146 
147         off = node->tree->node_size - 2;
148         for (i = be16_to_cpu(desc.num_recs); i >= 0; off -= 2, i--) {
149                 key_off = hfs_bnode_read_u16(node, off);
150                 dprint(DBG_BNODE_MOD, " %d", key_off);
151                 if (i && node->type == HFS_NODE_INDEX) {
152                         int tmp;
153 
154                         if (node->tree->attributes & HFS_TREE_VARIDXKEYS)
155                                 tmp = (hfs_bnode_read_u8(node, key_off) | 1) + 1;
156                         else
157                                 tmp = node->tree->max_key_len + 1;
158                         dprint(DBG_BNODE_MOD, " (%d,%d", tmp, hfs_bnode_read_u8(node, key_off));
159                         hfs_bnode_read(node, &cnid, key_off + tmp, 4);
160                         dprint(DBG_BNODE_MOD, ",%d)", be32_to_cpu(cnid));
161                 } else if (i && node->type == HFS_NODE_LEAF) {
162                         int tmp;
163 
164                         tmp = hfs_bnode_read_u8(node, key_off);
165                         dprint(DBG_BNODE_MOD, " (%d)", tmp);
166                 }
167         }
168         dprint(DBG_BNODE_MOD, "\n");
169 }
170 
171 void hfs_bnode_unlink(struct hfs_bnode *node)
172 {
173         struct hfs_btree *tree;
174         struct hfs_bnode *tmp;
175         __be32 cnid;
176 
177         tree = node->tree;
178         if (node->prev) {
179                 tmp = hfs_bnode_find(tree, node->prev);
180                 if (IS_ERR(tmp))
181                         return;
182                 tmp->next = node->next;
183                 cnid = cpu_to_be32(tmp->next);
184                 hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, next), 4);
185                 hfs_bnode_put(tmp);
186         } else if (node->type == HFS_NODE_LEAF)
187                 tree->leaf_head = node->next;
188 
189         if (node->next) {
190                 tmp = hfs_bnode_find(tree, node->next);
191                 if (IS_ERR(tmp))
192                         return;
193                 tmp->prev = node->prev;
194                 cnid = cpu_to_be32(tmp->prev);
195                 hfs_bnode_write(tmp, &cnid, offsetof(struct hfs_bnode_desc, prev), 4);
196                 hfs_bnode_put(tmp);
197         } else if (node->type == HFS_NODE_LEAF)
198                 tree->leaf_tail = node->prev;
199 
200         // move down?
201         if (!node->prev && !node->next) {
202                 printk(KERN_DEBUG "hfs_btree_del_level\n");
203         }
204         if (!node->parent) {
205                 tree->root = 0;
206                 tree->depth = 0;
207         }
208         set_bit(HFS_BNODE_DELETED, &node->flags);
209 }
210 
211 static inline int hfs_bnode_hash(u32 num)
212 {
213         num = (num >> 16) + num;
214         num += num >> 8;
215         return num & (NODE_HASH_SIZE - 1);
216 }
217 
218 struct hfs_bnode *hfs_bnode_findhash(struct hfs_btree *tree, u32 cnid)
219 {
220         struct hfs_bnode *node;
221 
222         if (cnid >= tree->node_count) {
223                 printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
224                 return NULL;
225         }
226 
227         for (node = tree->node_hash[hfs_bnode_hash(cnid)];
228              node; node = node->next_hash) {
229                 if (node->this == cnid) {
230                         return node;
231                 }
232         }
233         return NULL;
234 }
235 
236 static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
237 {
238         struct super_block *sb;
239         struct hfs_bnode *node, *node2;
240         struct address_space *mapping;
241         struct page *page;
242         int size, block, i, hash;
243         loff_t off;
244 
245         if (cnid >= tree->node_count) {
246                 printk(KERN_ERR "hfs: request for non-existent node %d in B*Tree\n", cnid);
247                 return NULL;
248         }
249 
250         sb = tree->inode->i_sb;
251         size = sizeof(struct hfs_bnode) + tree->pages_per_bnode *
252                 sizeof(struct page *);
253         node = kzalloc(size, GFP_KERNEL);
254         if (!node)
255                 return NULL;
256         node->tree = tree;
257         node->this = cnid;
258         set_bit(HFS_BNODE_NEW, &node->flags);
259         atomic_set(&node->refcnt, 1);
260         dprint(DBG_BNODE_REFS, "new_node(%d:%d): 1\n",
261                node->tree->cnid, node->this);
262         init_waitqueue_head(&node->lock_wq);
263         spin_lock(&tree->hash_lock);
264         node2 = hfs_bnode_findhash(tree, cnid);
265         if (!node2) {
266                 hash = hfs_bnode_hash(cnid);
267                 node->next_hash = tree->node_hash[hash];
268                 tree->node_hash[hash] = node;
269                 tree->node_hash_cnt++;
270         } else {
271                 spin_unlock(&tree->hash_lock);
272                 kfree(node);
273                 wait_event(node2->lock_wq, !test_bit(HFS_BNODE_NEW, &node2->flags));
274                 return node2;
275         }
276         spin_unlock(&tree->hash_lock);
277 
278         mapping = tree->inode->i_mapping;
279         off = (loff_t)cnid * tree->node_size;
280         block = off >> PAGE_CACHE_SHIFT;
281         node->page_offset = off & ~PAGE_CACHE_MASK;
282         for (i = 0; i < tree->pages_per_bnode; i++) {
283                 page = read_mapping_page(mapping, block++, NULL);
284                 if (IS_ERR(page))
285                         goto fail;
286                 if (PageError(page)) {
287                         page_cache_release(page);
288                         goto fail;
289                 }
290                 page_cache_release(page);
291                 node->page[i] = page;
292         }
293 
294         return node;
295 fail:
296         set_bit(HFS_BNODE_ERROR, &node->flags);
297         return node;
298 }
299 
300 void hfs_bnode_unhash(struct hfs_bnode *node)
301 {
302         struct hfs_bnode **p;
303 
304         dprint(DBG_BNODE_REFS, "remove_node(%d:%d): %d\n",
305                 node->tree->cnid, node->this, atomic_read(&node->refcnt));
306         for (p = &node->tree->node_hash[hfs_bnode_hash(node->this)];
307              *p && *p != node; p = &(*p)->next_hash)
308                 ;
309         BUG_ON(!*p);
310         *p = node->next_hash;
311         node->tree->node_hash_cnt--;
312 }
313 
314 /* Load a particular node out of a tree */
315 struct hfs_bnode *hfs_bnode_find(struct hfs_btree *tree, u32 num)
316 {
317         struct hfs_bnode *node;
318         struct hfs_bnode_desc *desc;
319         int i, rec_off, off, next_off;
320         int entry_size, key_size;
321 
322         spin_lock(&tree->hash_lock);
323         node = hfs_bnode_findhash(tree, num);
324         if (node) {
325                 hfs_bnode_get(node);
326                 spin_unlock(&tree->hash_lock);
327                 wait_event(node->lock_wq, !test_bit(HFS_BNODE_NEW, &node->flags));
328                 if (test_bit(HFS_BNODE_ERROR, &node->flags))
329                         goto node_error;
330                 return node;
331         }
332         spin_unlock(&tree->hash_lock);
333         node = __hfs_bnode_create(tree, num);
334         if (!node)
335                 return ERR_PTR(-ENOMEM);
336         if (test_bit(HFS_BNODE_ERROR, &node->flags))
337                 goto node_error;
338         if (!test_bit(HFS_BNODE_NEW, &node->flags))
339                 return node;
340 
341         desc = (struct hfs_bnode_desc *)(kmap(node->page[0]) + node->page_offset);
342         node->prev = be32_to_cpu(desc->prev);
343         node->next = be32_to_cpu(desc->next);
344         node->num_recs = be16_to_cpu(desc->num_recs);
345         node->type = desc->type;
346         node->height = desc->height;
347         kunmap(node->page[0]);
348 
349         switch (node->type) {
350         case HFS_NODE_HEADER:
351         case HFS_NODE_MAP:
352                 if (node->height != 0)
353                         goto node_error;
354                 break;
355         case HFS_NODE_LEAF:
356                 if (node->height != 1)
357                         goto node_error;
358                 break;
359         case HFS_NODE_INDEX:
360                 if (node->height <= 1 || node->height > tree->depth)
361                         goto node_error;
362                 break;
363         default:
364                 goto node_error;
365         }
366 
367         rec_off = tree->node_size - 2;
368         off = hfs_bnode_read_u16(node, rec_off);
369         if (off != sizeof(struct hfs_bnode_desc))
370                 goto node_error;
371         for (i = 1; i <= node->num_recs; off = next_off, i++) {
372                 rec_off -= 2;
373                 next_off = hfs_bnode_read_u16(node, rec_off);
374                 if (next_off <= off ||
375                     next_off > tree->node_size ||
376                     next_off & 1)
377                         goto node_error;
378                 entry_size = next_off - off;
379                 if (node->type != HFS_NODE_INDEX &&
380                     node->type != HFS_NODE_LEAF)
381                         continue;
382                 key_size = hfs_bnode_read_u8(node, off) + 1;
383                 if (key_size >= entry_size /*|| key_size & 1*/)
384                         goto node_error;
385         }
386         clear_bit(HFS_BNODE_NEW, &node->flags);
387         wake_up(&node->lock_wq);
388         return node;
389 
390 node_error:
391         set_bit(HFS_BNODE_ERROR, &node->flags);
392         clear_bit(HFS_BNODE_NEW, &node->flags);
393         wake_up(&node->lock_wq);
394         hfs_bnode_put(node);
395         return ERR_PTR(-EIO);
396 }
397 
398 void hfs_bnode_free(struct hfs_bnode *node)
399 {
400         //int i;
401 
402         //for (i = 0; i < node->tree->pages_per_bnode; i++)
403         //      if (node->page[i])
404         //              page_cache_release(node->page[i]);
405         kfree(node);
406 }
407 
408 struct hfs_bnode *hfs_bnode_create(struct hfs_btree *tree, u32 num)
409 {
410         struct hfs_bnode *node;
411         struct page **pagep;
412         int i;
413 
414         spin_lock(&tree->hash_lock);
415         node = hfs_bnode_findhash(tree, num);
416         spin_unlock(&tree->hash_lock);
417         BUG_ON(node);
418         node = __hfs_bnode_create(tree, num);
419         if (!node)
420                 return ERR_PTR(-ENOMEM);
421         if (test_bit(HFS_BNODE_ERROR, &node->flags)) {
422                 hfs_bnode_put(node);
423                 return ERR_PTR(-EIO);
424         }
425 
426         pagep = node->page;
427         memset(kmap(*pagep) + node->page_offset, 0,
428                min((int)PAGE_CACHE_SIZE, (int)tree->node_size));
429         set_page_dirty(*pagep);
430         kunmap(*pagep);
431         for (i = 1; i < tree->pages_per_bnode; i++) {
432                 memset(kmap(*++pagep), 0, PAGE_CACHE_SIZE);
433                 set_page_dirty(*pagep);
434                 kunmap(*pagep);
435         }
436         clear_bit(HFS_BNODE_NEW, &node->flags);
437         wake_up(&node->lock_wq);
438 
439         return node;
440 }
441 
442 void hfs_bnode_get(struct hfs_bnode *node)
443 {
444         if (node) {
445                 atomic_inc(&node->refcnt);
446                 dprint(DBG_BNODE_REFS, "get_node(%d:%d): %d\n",
447                        node->tree->cnid, node->this, atomic_read(&node->refcnt));
448         }
449 }
450 
451 /* Dispose of resources used by a node */
452 void hfs_bnode_put(struct hfs_bnode *node)
453 {
454         if (node) {
455                 struct hfs_btree *tree = node->tree;
456                 int i;
457 
458                 dprint(DBG_BNODE_REFS, "put_node(%d:%d): %d\n",
459                        node->tree->cnid, node->this, atomic_read(&node->refcnt));
460                 BUG_ON(!atomic_read(&node->refcnt));
461                 if (!atomic_dec_and_lock(&node->refcnt, &tree->hash_lock))
462                         return;
463                 for (i = 0; i < tree->pages_per_bnode; i++) {
464                         if (!node->page[i])
465                                 continue;
466                         mark_page_accessed(node->page[i]);
467                 }
468 
469                 if (test_bit(HFS_BNODE_DELETED, &node->flags)) {
470                         hfs_bnode_unhash(node);
471                         spin_unlock(&tree->hash_lock);
472                         hfs_bmap_free(node);
473                         hfs_bnode_free(node);
474                         return;
475                 }
476                 spin_unlock(&tree->hash_lock);
477         }
478 }
479 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp