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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 dprint(DBG_BNODE_REFS, "find_init: %d (%p)\n",
26 tree->cnid, __builtin_return_address(0));
27 mutex_lock(&tree->tree_lock);
28 return 0;
29}
30
31void hfs_find_exit(struct hfs_find_data *fd)
32{
33 hfs_bnode_put(fd->bnode);
34 kfree(fd->search_key);
35 dprint(DBG_BNODE_REFS, "find_exit: %d (%p)\n",
36 fd->tree->cnid, __builtin_return_address(0));
37 mutex_unlock(&fd->tree->tree_lock);
38 fd->tree = NULL;
39}
40
41
42int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd)
43{
44 int cmpval;
45 u16 off, len, keylen;
46 int rec;
47 int b, e;
48 int res;
49
50 b = 0;
51 e = bnode->num_recs - 1;
52 res = -ENOENT;
53 do {
54 rec = (e + b) / 2;
55 len = hfs_brec_lenoff(bnode, rec, &off);
56 keylen = hfs_brec_keylen(bnode, rec);
57 if (keylen == 0) {
58 res = -EINVAL;
59 goto fail;
60 }
61 hfs_bnode_read(bnode, fd->key, off, keylen);
62 cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
63 if (!cmpval) {
64 e = rec;
65 res = 0;
66 goto done;
67 }
68 if (cmpval < 0)
69 b = rec + 1;
70 else
71 e = rec - 1;
72 } while (b <= e);
73 if (rec != e && e >= 0) {
74 len = hfs_brec_lenoff(bnode, e, &off);
75 keylen = hfs_brec_keylen(bnode, e);
76 if (keylen == 0) {
77 res = -EINVAL;
78 goto fail;
79 }
80 hfs_bnode_read(bnode, fd->key, off, keylen);
81 }
82done:
83 fd->record = e;
84 fd->keyoffset = off;
85 fd->keylength = keylen;
86 fd->entryoffset = off + keylen;
87 fd->entrylength = len - keylen;
88fail:
89 return res;
90}
91
92
93
94int hfs_brec_find(struct hfs_find_data *fd)
95{
96 struct hfs_btree *tree;
97 struct hfs_bnode *bnode;
98 u32 nidx, parent;
99 __be32 data;
100 int height, res;
101
102 tree = fd->tree;
103 if (fd->bnode)
104 hfs_bnode_put(fd->bnode);
105 fd->bnode = NULL;
106 nidx = tree->root;
107 if (!nidx)
108 return -ENOENT;
109 height = tree->depth;
110 res = 0;
111 parent = 0;
112 for (;;) {
113 bnode = hfs_bnode_find(tree, nidx);
114 if (IS_ERR(bnode)) {
115 res = PTR_ERR(bnode);
116 bnode = NULL;
117 break;
118 }
119 if (bnode->height != height)
120 goto invalid;
121 if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
122 goto invalid;
123 bnode->parent = parent;
124
125 res = __hfs_brec_find(bnode, fd);
126 if (!height)
127 break;
128 if (fd->record < 0)
129 goto release;
130
131 parent = nidx;
132 hfs_bnode_read(bnode, &data, fd->entryoffset, 4);
133 nidx = be32_to_cpu(data);
134 hfs_bnode_put(bnode);
135 }
136 fd->bnode = bnode;
137 return res;
138
139invalid:
140 printk(KERN_ERR "hfs: inconsistency in B*Tree (%d,%d,%d,%u,%u)\n",
141 height, bnode->height, bnode->type, nidx, parent);
142 res = -EIO;
143release:
144 hfs_bnode_put(bnode);
145 return res;
146}
147
148int hfs_brec_read(struct hfs_find_data *fd, void *rec, int rec_len)
149{
150 int res;
151
152 res = hfs_brec_find(fd);
153 if (res)
154 return res;
155 if (fd->entrylength > rec_len)
156 return -EINVAL;
157 hfs_bnode_read(fd->bnode, rec, fd->entryoffset, fd->entrylength);
158 return 0;
159}
160
161int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
162{
163 struct hfs_btree *tree;
164 struct hfs_bnode *bnode;
165 int idx, res = 0;
166 u16 off, len, keylen;
167
168 bnode = fd->bnode;
169 tree = bnode->tree;
170
171 if (cnt < 0) {
172 cnt = -cnt;
173 while (cnt > fd->record) {
174 cnt -= fd->record + 1;
175 fd->record = bnode->num_recs - 1;
176 idx = bnode->prev;
177 if (!idx) {
178 res = -ENOENT;
179 goto out;
180 }
181 hfs_bnode_put(bnode);
182 bnode = hfs_bnode_find(tree, idx);
183 if (IS_ERR(bnode)) {
184 res = PTR_ERR(bnode);
185 bnode = NULL;
186 goto out;
187 }
188 }
189 fd->record -= cnt;
190 } else {
191 while (cnt >= bnode->num_recs - fd->record) {
192 cnt -= bnode->num_recs - fd->record;
193 fd->record = 0;
194 idx = bnode->next;
195 if (!idx) {
196 res = -ENOENT;
197 goto out;
198 }
199 hfs_bnode_put(bnode);
200 bnode = hfs_bnode_find(tree, idx);
201 if (IS_ERR(bnode)) {
202 res = PTR_ERR(bnode);
203 bnode = NULL;
204 goto out;
205 }
206 }
207 fd->record += cnt;
208 }
209
210 len = hfs_brec_lenoff(bnode, fd->record, &off);
211 keylen = hfs_brec_keylen(bnode, fd->record);
212 if (keylen == 0) {
213 res = -EINVAL;
214 goto out;
215 }
216 fd->keyoffset = off;
217 fd->keylength = keylen;
218 fd->entryoffset = off + keylen;
219 fd->entrylength = len - keylen;
220 hfs_bnode_read(bnode, fd->key, off, keylen);
221out:
222 fd->bnode = bnode;
223 return res;
224}
225
