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