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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 BUG_ON(!rec_found);
122 b = 0;
123 e = bnode->num_recs - 1;
124 res = -ENOENT;
125 do {
126 rec = (e + b) / 2;
127 len = hfs_brec_lenoff(bnode, rec, &off);
128 keylen = hfs_brec_keylen(bnode, rec);
129 if (keylen == 0) {
130 res = -EINVAL;
131 goto fail;
132 }
133 hfs_bnode_read(bnode, fd->key, off, keylen);
134 if (rec_found(bnode, fd, &b, &e, &rec)) {
135 res = 0;
136 goto done;
137 }
138 } while (b <= e);
139
140 if (rec != e && e >= 0) {
141 len = hfs_brec_lenoff(bnode, e, &off);
142 keylen = hfs_brec_keylen(bnode, e);
143 if (keylen == 0) {
144 res = -EINVAL;
145 goto fail;
146 }
147 hfs_bnode_read(bnode, fd->key, off, keylen);
148 }
149
150done:
151 fd->record = e;
152 fd->keyoffset = off;
153 fd->keylength = keylen;
154 fd->entryoffset = off + keylen;
155 fd->entrylength = len - keylen;
156
157fail:
158 return res;
159}
160
161
162
163int hfs_brec_find(struct hfs_find_data *fd, search_strategy_t do_key_compare)
164{
165 struct hfs_btree *tree;
166 struct hfs_bnode *bnode;
167 u32 nidx, parent;
168 __be32 data;
169 int height, res;
170
171 tree = fd->tree;
172 if (fd->bnode)
173 hfs_bnode_put(fd->bnode);
174 fd->bnode = NULL;
175 nidx = tree->root;
176 if (!nidx)
177 return -ENOENT;
178 height = tree->depth;
179 res = 0;
180 parent = 0;
181 for (;;) {
182 bnode = hfs_bnode_find(tree, nidx);
183 if (IS_ERR(bnode)) {
184 res = PTR_ERR(bnode);
185 bnode = NULL;
186 break;
187 }
188 if (bnode->height != height)
189 goto invalid;
190 if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
191 goto invalid;
192 bnode->parent = parent;
193
194 res = __hfs_brec_find(bnode, fd, do_key_compare);
195 if (!height)
196 break;
197 if (fd->record < 0)
198 goto release;
199
200 parent = nidx;
201 hfs_bnode_read(bnode, &data, fd->entryoffset, 4);
202 nidx = be32_to_cpu(data);
203 hfs_bnode_put(bnode);
204 }
205 fd->bnode = bnode;
206 return res;
207
208invalid:
209 pr_err("inconsistency in B*Tree (%d,%d,%d,%u,%u)\n",
210 height, bnode->height, bnode->type, nidx, parent);
211 res = -EIO;
212release:
213 hfs_bnode_put(bnode);
214 return res;
215}
216
217int hfs_brec_read(struct hfs_find_data *fd, void *rec, int rec_len)
218{
219 int res;
220
221 res = hfs_brec_find(fd, hfs_find_rec_by_key);
222 if (res)
223 return res;
224 if (fd->entrylength > rec_len)
225 return -EINVAL;
226 hfs_bnode_read(fd->bnode, rec, fd->entryoffset, fd->entrylength);
227 return 0;
228}
229
230int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
231{
232 struct hfs_btree *tree;
233 struct hfs_bnode *bnode;
234 int idx, res = 0;
235 u16 off, len, keylen;
236
237 bnode = fd->bnode;
238 tree = bnode->tree;
239
240 if (cnt < 0) {
241 cnt = -cnt;
242 while (cnt > fd->record) {
243 cnt -= fd->record + 1;
244 fd->record = bnode->num_recs - 1;
245 idx = bnode->prev;
246 if (!idx) {
247 res = -ENOENT;
248 goto out;
249 }
250 hfs_bnode_put(bnode);
251 bnode = hfs_bnode_find(tree, idx);
252 if (IS_ERR(bnode)) {
253 res = PTR_ERR(bnode);
254 bnode = NULL;
255 goto out;
256 }
257 }
258 fd->record -= cnt;
259 } else {
260 while (cnt >= bnode->num_recs - fd->record) {
261 cnt -= bnode->num_recs - fd->record;
262 fd->record = 0;
263 idx = bnode->next;
264 if (!idx) {
265 res = -ENOENT;
266 goto out;
267 }
268 hfs_bnode_put(bnode);
269 bnode = hfs_bnode_find(tree, idx);
270 if (IS_ERR(bnode)) {
271 res = PTR_ERR(bnode);
272 bnode = NULL;
273 goto out;
274 }
275 }
276 fd->record += cnt;
277 }
278
279 len = hfs_brec_lenoff(bnode, fd->record, &off);
280 keylen = hfs_brec_keylen(bnode, fd->record);
281 if (keylen == 0) {
282 res = -EINVAL;
283 goto out;
284 }
285 fd->keyoffset = off;
286 fd->keylength = keylen;
287 fd->entryoffset = off + keylen;
288 fd->entrylength = len - keylen;
289 hfs_bnode_read(bnode, fd->key, off, keylen);
290out:
291 fd->bnode = bnode;
292 return res;
293}
294
