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

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

Version: ~ [ linux-5.9 ] ~ [ linux-5.8.14 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.70 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.150 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.200 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.238 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.238 ] ~ [ 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-3.16.85 ] ~ [ 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-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 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  *  linux/fs/hfs/brec.c
  4  *
  5  * Copyright (C) 2001
  6  * Brad Boyer (flar@allandria.com)
  7  * (C) 2003 Ardis Technologies <roman@ardistech.com>
  8  *
  9  * Handle individual btree records
 10  */
 11 
 12 #include "btree.h"
 13 
 14 static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd);
 15 static int hfs_brec_update_parent(struct hfs_find_data *fd);
 16 static int hfs_btree_inc_height(struct hfs_btree *tree);
 17 
 18 /* Get the length and offset of the given record in the given node */
 19 u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off)
 20 {
 21         __be16 retval[2];
 22         u16 dataoff;
 23 
 24         dataoff = node->tree->node_size - (rec + 2) * 2;
 25         hfs_bnode_read(node, retval, dataoff, 4);
 26         *off = be16_to_cpu(retval[1]);
 27         return be16_to_cpu(retval[0]) - *off;
 28 }
 29 
 30 /* Get the length of the key from a keyed record */
 31 u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
 32 {
 33         u16 retval, recoff;
 34 
 35         if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF)
 36                 return 0;
 37 
 38         if ((node->type == HFS_NODE_INDEX) &&
 39            !(node->tree->attributes & HFS_TREE_VARIDXKEYS)) {
 40                 if (node->tree->attributes & HFS_TREE_BIGKEYS)
 41                         retval = node->tree->max_key_len + 2;
 42                 else
 43                         retval = node->tree->max_key_len + 1;
 44         } else {
 45                 recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2);
 46                 if (!recoff)
 47                         return 0;
 48                 if (node->tree->attributes & HFS_TREE_BIGKEYS) {
 49                         retval = hfs_bnode_read_u16(node, recoff) + 2;
 50                         if (retval > node->tree->max_key_len + 2) {
 51                                 pr_err("keylen %d too large\n", retval);
 52                                 retval = 0;
 53                         }
 54                 } else {
 55                         retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
 56                         if (retval > node->tree->max_key_len + 1) {
 57                                 pr_err("keylen %d too large\n", retval);
 58                                 retval = 0;
 59                         }
 60                 }
 61         }
 62         return retval;
 63 }
 64 
 65 int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
 66 {
 67         struct hfs_btree *tree;
 68         struct hfs_bnode *node, *new_node;
 69         int size, key_len, rec;
 70         int data_off, end_off;
 71         int idx_rec_off, data_rec_off, end_rec_off;
 72         __be32 cnid;
 73 
 74         tree = fd->tree;
 75         if (!fd->bnode) {
 76                 if (!tree->root)
 77                         hfs_btree_inc_height(tree);
 78                 fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
 79                 if (IS_ERR(fd->bnode))
 80                         return PTR_ERR(fd->bnode);
 81                 fd->record = -1;
 82         }
 83         new_node = NULL;
 84         key_len = (fd->search_key->key_len | 1) + 1;
 85 again:
 86         /* new record idx and complete record size */
 87         rec = fd->record + 1;
 88         size = key_len + entry_len;
 89 
 90         node = fd->bnode;
 91         hfs_bnode_dump(node);
 92         /* get last offset */
 93         end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
 94         end_off = hfs_bnode_read_u16(node, end_rec_off);
 95         end_rec_off -= 2;
 96         hfs_dbg(BNODE_MOD, "insert_rec: %d, %d, %d, %d\n",
 97                 rec, size, end_off, end_rec_off);
 98         if (size > end_rec_off - end_off) {
 99                 if (new_node)
100                         panic("not enough room!\n");
101                 new_node = hfs_bnode_split(fd);
102                 if (IS_ERR(new_node))
103                         return PTR_ERR(new_node);
104                 goto again;
105         }
106         if (node->type == HFS_NODE_LEAF) {
107                 tree->leaf_count++;
108                 mark_inode_dirty(tree->inode);
109         }
110         node->num_recs++;
111         /* write new last offset */
112         hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
113         hfs_bnode_write_u16(node, end_rec_off, end_off + size);
114         data_off = end_off;
115         data_rec_off = end_rec_off + 2;
116         idx_rec_off = tree->node_size - (rec + 1) * 2;
117         if (idx_rec_off == data_rec_off)
118                 goto skip;
119         /* move all following entries */
120         do {
121                 data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
122                 hfs_bnode_write_u16(node, data_rec_off, data_off + size);
123                 data_rec_off += 2;
124         } while (data_rec_off < idx_rec_off);
125 
126         /* move data away */
127         hfs_bnode_move(node, data_off + size, data_off,
128                        end_off - data_off);
129 
130 skip:
131         hfs_bnode_write(node, fd->search_key, data_off, key_len);
132         hfs_bnode_write(node, entry, data_off + key_len, entry_len);
133         hfs_bnode_dump(node);
134 
135         /*
136          * update parent key if we inserted a key
137          * at the start of the node and it is not the new node
138          */
139         if (!rec && new_node != node) {
140                 hfs_bnode_read_key(node, fd->search_key, data_off + size);
141                 hfs_brec_update_parent(fd);
142         }
143 
144         if (new_node) {
145                 hfs_bnode_put(fd->bnode);
146                 if (!new_node->parent) {
147                         hfs_btree_inc_height(tree);
148                         new_node->parent = tree->root;
149                 }
150                 fd->bnode = hfs_bnode_find(tree, new_node->parent);
151 
152                 /* create index data entry */
153                 cnid = cpu_to_be32(new_node->this);
154                 entry = &cnid;
155                 entry_len = sizeof(cnid);
156 
157                 /* get index key */
158                 hfs_bnode_read_key(new_node, fd->search_key, 14);
159                 __hfs_brec_find(fd->bnode, fd);
160 
161                 hfs_bnode_put(new_node);
162                 new_node = NULL;
163 
164                 if (tree->attributes & HFS_TREE_VARIDXKEYS)
165                         key_len = fd->search_key->key_len + 1;
166                 else {
167                         fd->search_key->key_len = tree->max_key_len;
168                         key_len = tree->max_key_len + 1;
169                 }
170                 goto again;
171         }
172 
173         return 0;
174 }
175 
176 int hfs_brec_remove(struct hfs_find_data *fd)
177 {
178         struct hfs_btree *tree;
179         struct hfs_bnode *node, *parent;
180         int end_off, rec_off, data_off, size;
181 
182         tree = fd->tree;
183         node = fd->bnode;
184 again:
185         rec_off = tree->node_size - (fd->record + 2) * 2;
186         end_off = tree->node_size - (node->num_recs + 1) * 2;
187 
188         if (node->type == HFS_NODE_LEAF) {
189                 tree->leaf_count--;
190                 mark_inode_dirty(tree->inode);
191         }
192         hfs_bnode_dump(node);
193         hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n",
194                 fd->record, fd->keylength + fd->entrylength);
195         if (!--node->num_recs) {
196                 hfs_bnode_unlink(node);
197                 if (!node->parent)
198                         return 0;
199                 parent = hfs_bnode_find(tree, node->parent);
200                 if (IS_ERR(parent))
201                         return PTR_ERR(parent);
202                 hfs_bnode_put(node);
203                 node = fd->bnode = parent;
204 
205                 __hfs_brec_find(node, fd);
206                 goto again;
207         }
208         hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
209 
210         if (rec_off == end_off)
211                 goto skip;
212         size = fd->keylength + fd->entrylength;
213 
214         do {
215                 data_off = hfs_bnode_read_u16(node, rec_off);
216                 hfs_bnode_write_u16(node, rec_off + 2, data_off - size);
217                 rec_off -= 2;
218         } while (rec_off >= end_off);
219 
220         /* fill hole */
221         hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size,
222                        data_off - fd->keyoffset - size);
223 skip:
224         hfs_bnode_dump(node);
225         if (!fd->record)
226                 hfs_brec_update_parent(fd);
227         return 0;
228 }
229 
230 static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
231 {
232         struct hfs_btree *tree;
233         struct hfs_bnode *node, *new_node, *next_node;
234         struct hfs_bnode_desc node_desc;
235         int num_recs, new_rec_off, new_off, old_rec_off;
236         int data_start, data_end, size;
237 
238         tree = fd->tree;
239         node = fd->bnode;
240         new_node = hfs_bmap_alloc(tree);
241         if (IS_ERR(new_node))
242                 return new_node;
243         hfs_bnode_get(node);
244         hfs_dbg(BNODE_MOD, "split_nodes: %d - %d - %d\n",
245                 node->this, new_node->this, node->next);
246         new_node->next = node->next;
247         new_node->prev = node->this;
248         new_node->parent = node->parent;
249         new_node->type = node->type;
250         new_node->height = node->height;
251 
252         if (node->next)
253                 next_node = hfs_bnode_find(tree, node->next);
254         else
255                 next_node = NULL;
256 
257         if (IS_ERR(next_node)) {
258                 hfs_bnode_put(node);
259                 hfs_bnode_put(new_node);
260                 return next_node;
261         }
262 
263         size = tree->node_size / 2 - node->num_recs * 2 - 14;
264         old_rec_off = tree->node_size - 4;
265         num_recs = 1;
266         for (;;) {
267                 data_start = hfs_bnode_read_u16(node, old_rec_off);
268                 if (data_start > size)
269                         break;
270                 old_rec_off -= 2;
271                 if (++num_recs < node->num_recs)
272                         continue;
273                 /* panic? */
274                 hfs_bnode_put(node);
275                 hfs_bnode_put(new_node);
276                 if (next_node)
277                         hfs_bnode_put(next_node);
278                 return ERR_PTR(-ENOSPC);
279         }
280 
281         if (fd->record + 1 < num_recs) {
282                 /* new record is in the lower half,
283                  * so leave some more space there
284                  */
285                 old_rec_off += 2;
286                 num_recs--;
287                 data_start = hfs_bnode_read_u16(node, old_rec_off);
288         } else {
289                 hfs_bnode_put(node);
290                 hfs_bnode_get(new_node);
291                 fd->bnode = new_node;
292                 fd->record -= num_recs;
293                 fd->keyoffset -= data_start - 14;
294                 fd->entryoffset -= data_start - 14;
295         }
296         new_node->num_recs = node->num_recs - num_recs;
297         node->num_recs = num_recs;
298 
299         new_rec_off = tree->node_size - 2;
300         new_off = 14;
301         size = data_start - new_off;
302         num_recs = new_node->num_recs;
303         data_end = data_start;
304         while (num_recs) {
305                 hfs_bnode_write_u16(new_node, new_rec_off, new_off);
306                 old_rec_off -= 2;
307                 new_rec_off -= 2;
308                 data_end = hfs_bnode_read_u16(node, old_rec_off);
309                 new_off = data_end - size;
310                 num_recs--;
311         }
312         hfs_bnode_write_u16(new_node, new_rec_off, new_off);
313         hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
314 
315         /* update new bnode header */
316         node_desc.next = cpu_to_be32(new_node->next);
317         node_desc.prev = cpu_to_be32(new_node->prev);
318         node_desc.type = new_node->type;
319         node_desc.height = new_node->height;
320         node_desc.num_recs = cpu_to_be16(new_node->num_recs);
321         node_desc.reserved = 0;
322         hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
323 
324         /* update previous bnode header */
325         node->next = new_node->this;
326         hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
327         node_desc.next = cpu_to_be32(node->next);
328         node_desc.num_recs = cpu_to_be16(node->num_recs);
329         hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
330 
331         /* update next bnode header */
332         if (next_node) {
333                 next_node->prev = new_node->this;
334                 hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
335                 node_desc.prev = cpu_to_be32(next_node->prev);
336                 hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
337                 hfs_bnode_put(next_node);
338         } else if (node->this == tree->leaf_tail) {
339                 /* if there is no next node, this might be the new tail */
340                 tree->leaf_tail = new_node->this;
341                 mark_inode_dirty(tree->inode);
342         }
343 
344         hfs_bnode_dump(node);
345         hfs_bnode_dump(new_node);
346         hfs_bnode_put(node);
347 
348         return new_node;
349 }
350 
351 static int hfs_brec_update_parent(struct hfs_find_data *fd)
352 {
353         struct hfs_btree *tree;
354         struct hfs_bnode *node, *new_node, *parent;
355         int newkeylen, diff;
356         int rec, rec_off, end_rec_off;
357         int start_off, end_off;
358 
359         tree = fd->tree;
360         node = fd->bnode;
361         new_node = NULL;
362         if (!node->parent)
363                 return 0;
364 
365 again:
366         parent = hfs_bnode_find(tree, node->parent);
367         if (IS_ERR(parent))
368                 return PTR_ERR(parent);
369         __hfs_brec_find(parent, fd);
370         if (fd->record < 0)
371                 return -ENOENT;
372         hfs_bnode_dump(parent);
373         rec = fd->record;
374 
375         /* size difference between old and new key */
376         if (tree->attributes & HFS_TREE_VARIDXKEYS)
377                 newkeylen = (hfs_bnode_read_u8(node, 14) | 1) + 1;
378         else
379                 fd->keylength = newkeylen = tree->max_key_len + 1;
380         hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n",
381                 rec, fd->keylength, newkeylen);
382 
383         rec_off = tree->node_size - (rec + 2) * 2;
384         end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
385         diff = newkeylen - fd->keylength;
386         if (!diff)
387                 goto skip;
388         if (diff > 0) {
389                 end_off = hfs_bnode_read_u16(parent, end_rec_off);
390                 if (end_rec_off - end_off < diff) {
391 
392                         printk(KERN_DEBUG "splitting index node...\n");
393                         fd->bnode = parent;
394                         new_node = hfs_bnode_split(fd);
395                         if (IS_ERR(new_node))
396                                 return PTR_ERR(new_node);
397                         parent = fd->bnode;
398                         rec = fd->record;
399                         rec_off = tree->node_size - (rec + 2) * 2;
400                         end_rec_off = tree->node_size - (parent->num_recs + 1) * 2;
401                 }
402         }
403 
404         end_off = start_off = hfs_bnode_read_u16(parent, rec_off);
405         hfs_bnode_write_u16(parent, rec_off, start_off + diff);
406         start_off -= 4; /* move previous cnid too */
407 
408         while (rec_off > end_rec_off) {
409                 rec_off -= 2;
410                 end_off = hfs_bnode_read_u16(parent, rec_off);
411                 hfs_bnode_write_u16(parent, rec_off, end_off + diff);
412         }
413         hfs_bnode_move(parent, start_off + diff, start_off,
414                        end_off - start_off);
415 skip:
416         hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen);
417         if (!(tree->attributes & HFS_TREE_VARIDXKEYS))
418                 hfs_bnode_write_u8(parent, fd->keyoffset, newkeylen - 1);
419         hfs_bnode_dump(parent);
420 
421         hfs_bnode_put(node);
422         node = parent;
423 
424         if (new_node) {
425                 __be32 cnid;
426 
427                 fd->bnode = hfs_bnode_find(tree, new_node->parent);
428                 /* create index key and entry */
429                 hfs_bnode_read_key(new_node, fd->search_key, 14);
430                 cnid = cpu_to_be32(new_node->this);
431 
432                 __hfs_brec_find(fd->bnode, fd);
433                 hfs_brec_insert(fd, &cnid, sizeof(cnid));
434                 hfs_bnode_put(fd->bnode);
435                 hfs_bnode_put(new_node);
436 
437                 if (!rec) {
438                         if (new_node == node)
439                                 goto out;
440                         /* restore search_key */
441                         hfs_bnode_read_key(node, fd->search_key, 14);
442                 }
443         }
444 
445         if (!rec && node->parent)
446                 goto again;
447 out:
448         fd->bnode = node;
449         return 0;
450 }
451 
452 static int hfs_btree_inc_height(struct hfs_btree *tree)
453 {
454         struct hfs_bnode *node, *new_node;
455         struct hfs_bnode_desc node_desc;
456         int key_size, rec;
457         __be32 cnid;
458 
459         node = NULL;
460         if (tree->root) {
461                 node = hfs_bnode_find(tree, tree->root);
462                 if (IS_ERR(node))
463                         return PTR_ERR(node);
464         }
465         new_node = hfs_bmap_alloc(tree);
466         if (IS_ERR(new_node)) {
467                 hfs_bnode_put(node);
468                 return PTR_ERR(new_node);
469         }
470 
471         tree->root = new_node->this;
472         if (!tree->depth) {
473                 tree->leaf_head = tree->leaf_tail = new_node->this;
474                 new_node->type = HFS_NODE_LEAF;
475                 new_node->num_recs = 0;
476         } else {
477                 new_node->type = HFS_NODE_INDEX;
478                 new_node->num_recs = 1;
479         }
480         new_node->parent = 0;
481         new_node->next = 0;
482         new_node->prev = 0;
483         new_node->height = ++tree->depth;
484 
485         node_desc.next = cpu_to_be32(new_node->next);
486         node_desc.prev = cpu_to_be32(new_node->prev);
487         node_desc.type = new_node->type;
488         node_desc.height = new_node->height;
489         node_desc.num_recs = cpu_to_be16(new_node->num_recs);
490         node_desc.reserved = 0;
491         hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
492 
493         rec = tree->node_size - 2;
494         hfs_bnode_write_u16(new_node, rec, 14);
495 
496         if (node) {
497                 /* insert old root idx into new root */
498                 node->parent = tree->root;
499                 if (node->type == HFS_NODE_LEAF ||
500                     tree->attributes & HFS_TREE_VARIDXKEYS)
501                         key_size = hfs_bnode_read_u8(node, 14) + 1;
502                 else
503                         key_size = tree->max_key_len + 1;
504                 hfs_bnode_copy(new_node, 14, node, 14, key_size);
505 
506                 if (!(tree->attributes & HFS_TREE_VARIDXKEYS)) {
507                         key_size = tree->max_key_len + 1;
508                         hfs_bnode_write_u8(new_node, 14, tree->max_key_len);
509                 }
510                 key_size = (key_size + 1) & -2;
511                 cnid = cpu_to_be32(node->this);
512                 hfs_bnode_write(new_node, &cnid, 14 + key_size, 4);
513 
514                 rec -= 2;
515                 hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4);
516 
517                 hfs_bnode_put(node);
518         }
519         hfs_bnode_put(new_node);
520         mark_inode_dirty(tree->inode);
521 
522         return 0;
523 }
524 

~ [ 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