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11#include <linux/slab.h>
12#include "hfsplus_fs.h"
13
14int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
15{
16 void *ptr;
17
18 fd->tree = tree;
19 fd->bnode = NULL;
20 ptr = kmalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
21 if (!ptr)
22 return -ENOMEM;
23 fd->search_key = ptr;
24 fd->key = ptr + tree->max_key_len + 2;
25 hfs_dbg(BNODE_REFS, "find_init: %d (%p)\n",
26 tree->cnid, __builtin_return_address(0));
27 switch (tree->cnid) {
28 case HFSPLUS_CAT_CNID:
29 mutex_lock_nested(&tree->tree_lock, CATALOG_BTREE_MUTEX);
30 break;
31 case HFSPLUS_EXT_CNID:
32 mutex_lock_nested(&tree->tree_lock, EXTENTS_BTREE_MUTEX);
33 break;
34 case HFSPLUS_ATTR_CNID:
35 mutex_lock_nested(&tree->tree_lock, ATTR_BTREE_MUTEX);
36 break;
37 default:
38 BUG();
39 }
40 return 0;
41}
42
43void hfs_find_exit(struct hfs_find_data *fd)
44{
45 hfs_bnode_put(fd->bnode);
46 kfree(fd->search_key);
47 hfs_dbg(BNODE_REFS, "find_exit: %d (%p)\n",
48 fd->tree->cnid, __builtin_return_address(0));
49 mutex_unlock(&fd->tree->tree_lock);
50 fd->tree = NULL;
51}
52
53int hfs_find_1st_rec_by_cnid(struct hfs_bnode *bnode,
54 struct hfs_find_data *fd,
55 int *begin,
56 int *end,
57 int *cur_rec)
58{
59 __be32 cur_cnid;
60 __be32 search_cnid;
61
62 if (bnode->tree->cnid == HFSPLUS_EXT_CNID) {
63 cur_cnid = fd->key->ext.cnid;
64 search_cnid = fd->search_key->ext.cnid;
65 } else if (bnode->tree->cnid == HFSPLUS_CAT_CNID) {
66 cur_cnid = fd->key->cat.parent;
67 search_cnid = fd->search_key->cat.parent;
68 } else if (bnode->tree->cnid == HFSPLUS_ATTR_CNID) {
69 cur_cnid = fd->key->attr.cnid;
70 search_cnid = fd->search_key->attr.cnid;
71 } else {
72 cur_cnid = 0;
73 search_cnid = 0;
74 BUG();
75 }
76
77 if (cur_cnid == search_cnid) {
78 (*end) = (*cur_rec);
79 if ((*begin) == (*end))
80 return 1;
81 } else {
82 if (be32_to_cpu(cur_cnid) < be32_to_cpu(search_cnid))
83 (*begin) = (*cur_rec) + 1;
84 else
85 (*end) = (*cur_rec) - 1;
86 }
87
88 return 0;
89}
90
91int hfs_find_rec_by_key(struct hfs_bnode *bnode,
92 struct hfs_find_data *fd,
93 int *begin,
94 int *end,
95 int *cur_rec)
96{
97 int cmpval;
98
99 cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
100 if (!cmpval) {
101 (*end) = (*cur_rec);
102 return 1;
103 }
104 if (cmpval < 0)
105 (*begin) = (*cur_rec) + 1;
106 else
107 *(end) = (*cur_rec) - 1;
108
109 return 0;
110}
111
112
113int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd,
114 search_strategy_t rec_found)
115{
116 u16 off, len, keylen;
117 int rec;
118 int b, e;
119 int res;
120
121 if (!rec_found)
122 BUG();
123
124 b = 0;
125 e = bnode->num_recs - 1;
126 res = -ENOENT;
127 do {
128 rec = (e + b) / 2;
129 len = hfs_brec_lenoff(bnode, rec, &off);
130 keylen = hfs_brec_keylen(bnode, rec);
131 if (keylen == 0) {
132 res = -EINVAL;
133 goto fail;
134 }
135 hfs_bnode_read(bnode, fd->key, off, keylen);
136 if (rec_found(bnode, fd, &b, &e, &rec)) {
137 res = 0;
138 goto done;
139 }
140 } while (b <= e);
141
142 if (rec != e && e >= 0) {
143 len = hfs_brec_lenoff(bnode, e, &off);
144 keylen = hfs_brec_keylen(bnode, e);
145 if (keylen == 0) {
146 res = -EINVAL;
147 goto fail;
148 }
149 hfs_bnode_read(bnode, fd->key, off, keylen);
150 }
151
152done:
153 fd->record = e;
154 fd->keyoffset = off;
155 fd->keylength = keylen;
156 fd->entryoffset = off + keylen;
157 fd->entrylength = len - keylen;
158
159fail:
160 return res;
161}
162
163
164
165int hfs_brec_find(struct hfs_find_data *fd, search_strategy_t do_key_compare)
166{
167 struct hfs_btree *tree;
168 struct hfs_bnode *bnode;
169 u32 nidx, parent;
170 __be32 data;
171 int height, res;
172
173 tree = fd->tree;
174 if (fd->bnode)
175 hfs_bnode_put(fd->bnode);
176 fd->bnode = NULL;
177 nidx = tree->root;
178 if (!nidx)
179 return -ENOENT;
180 height = tree->depth;
181 res = 0;
182 parent = 0;
183 for (;;) {
184 bnode = hfs_bnode_find(tree, nidx);
185 if (IS_ERR(bnode)) {
186 res = PTR_ERR(bnode);
187 bnode = NULL;
188 break;
189 }
190 if (bnode->height != height)
191 goto invalid;
192 if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
193 goto invalid;
194 bnode->parent = parent;
195
196 res = __hfs_brec_find(bnode, fd, do_key_compare);
197 if (!height)
198 break;
199 if (fd->record < 0)
200 goto release;
201
202 parent = nidx;
203 hfs_bnode_read(bnode, &data, fd->entryoffset, 4);
204 nidx = be32_to_cpu(data);
205 hfs_bnode_put(bnode);
206 }
207 fd->bnode = bnode;
208 return res;
209
210invalid:
211 pr_err("inconsistency in B*Tree (%d,%d,%d,%u,%u)\n",
212 height, bnode->height, bnode->type, nidx, parent);
213 res = -EIO;
214release:
215 hfs_bnode_put(bnode);
216 return res;
217}
218
219int hfs_brec_read(struct hfs_find_data *fd, void *rec, int rec_len)
220{
221 int res;
222
223 res = hfs_brec_find(fd, hfs_find_rec_by_key);
224 if (res)
225 return res;
226 if (fd->entrylength > rec_len)
227 return -EINVAL;
228 hfs_bnode_read(fd->bnode, rec, fd->entryoffset, fd->entrylength);
229 return 0;
230}
231
232int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
233{
234 struct hfs_btree *tree;
235 struct hfs_bnode *bnode;
236 int idx, res = 0;
237 u16 off, len, keylen;
238
239 bnode = fd->bnode;
240 tree = bnode->tree;
241
242 if (cnt < 0) {
243 cnt = -cnt;
244 while (cnt > fd->record) {
245 cnt -= fd->record + 1;
246 fd->record = bnode->num_recs - 1;
247 idx = bnode->prev;
248 if (!idx) {
249 res = -ENOENT;
250 goto out;
251 }
252 hfs_bnode_put(bnode);
253 bnode = hfs_bnode_find(tree, idx);
254 if (IS_ERR(bnode)) {
255 res = PTR_ERR(bnode);
256 bnode = NULL;
257 goto out;
258 }
259 }
260 fd->record -= cnt;
261 } else {
262 while (cnt >= bnode->num_recs - fd->record) {
263 cnt -= bnode->num_recs - fd->record;
264 fd->record = 0;
265 idx = bnode->next;
266 if (!idx) {
267 res = -ENOENT;
268 goto out;
269 }
270 hfs_bnode_put(bnode);
271 bnode = hfs_bnode_find(tree, idx);
272 if (IS_ERR(bnode)) {
273 res = PTR_ERR(bnode);
274 bnode = NULL;
275 goto out;
276 }
277 }
278 fd->record += cnt;
279 }
280
281 len = hfs_brec_lenoff(bnode, fd->record, &off);
282 keylen = hfs_brec_keylen(bnode, fd->record);
283 if (keylen == 0) {
284 res = -EINVAL;
285 goto out;
286 }
287 fd->keyoffset = off;
288 fd->keylength = keylen;
289 fd->entryoffset = off + keylen;
290 fd->entrylength = len - keylen;
291 hfs_bnode_read(bnode, fd->key, off, keylen);
292out:
293 fd->bnode = bnode;
294 return res;
295}
296
