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8
9#include <linux/smp_lock.h>
10#include "isofs.h"
11
12
13
14
15
16
17static int
18isofs_cmp(struct dentry *dentry, const char *compare, int dlen)
19{
20 struct qstr qstr;
21
22 if (!compare)
23 return 1;
24
25
26 if (dlen == 1) {
27
28 if (compare[0] == 0) {
29 if (!dentry->d_name.len)
30 return 0;
31 compare = ".";
32 } else if (compare[0] == 1) {
33 compare = "..";
34 dlen = 2;
35 }
36 }
37
38 qstr.name = compare;
39 qstr.len = dlen;
40 return dentry->d_op->d_compare(dentry, &dentry->d_name, &qstr);
41}
42
43
44
45
46
47
48
49static unsigned long
50isofs_find_entry(struct inode *dir, struct dentry *dentry,
51 unsigned long *block_rv, unsigned long *offset_rv,
52 char *tmpname, struct iso_directory_record *tmpde)
53{
54 unsigned long bufsize = ISOFS_BUFFER_SIZE(dir);
55 unsigned char bufbits = ISOFS_BUFFER_BITS(dir);
56 unsigned long block, f_pos, offset, block_saved, offset_saved;
57 struct buffer_head *bh = NULL;
58 struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb);
59
60 if (!ISOFS_I(dir)->i_first_extent)
61 return 0;
62
63 f_pos = 0;
64 offset = 0;
65 block = 0;
66
67 while (f_pos < dir->i_size) {
68 struct iso_directory_record *de;
69 int de_len, match, i, dlen;
70 char *dpnt;
71
72 if (!bh) {
73 bh = isofs_bread(dir, block);
74 if (!bh)
75 return 0;
76 }
77
78 de = (struct iso_directory_record *) (bh->b_data + offset);
79
80 de_len = *(unsigned char *) de;
81 if (!de_len) {
82 brelse(bh);
83 bh = NULL;
84 f_pos = (f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
85 block = f_pos >> bufbits;
86 offset = 0;
87 continue;
88 }
89
90 block_saved = bh->b_blocknr;
91 offset_saved = offset;
92 offset += de_len;
93 f_pos += de_len;
94
95
96 if (offset >= bufsize) {
97 int slop = bufsize - offset + de_len;
98 memcpy(tmpde, de, slop);
99 offset &= bufsize - 1;
100 block++;
101 brelse(bh);
102 bh = NULL;
103 if (offset) {
104 bh = isofs_bread(dir, block);
105 if (!bh)
106 return 0;
107 memcpy((void *) tmpde + slop, bh->b_data, offset);
108 }
109 de = tmpde;
110 }
111
112 dlen = de->name_len[0];
113 dpnt = de->name;
114
115 if (sbi->s_rock &&
116 ((i = get_rock_ridge_filename(de, tmpname, dir)))) {
117 dlen = i;
118 dpnt = tmpname;
119#ifdef CONFIG_JOLIET
120 } else if (sbi->s_joliet_level) {
121 dlen = get_joliet_filename(de, tmpname, dir);
122 dpnt = tmpname;
123#endif
124 } else if (sbi->s_mapping == 'a') {
125 dlen = get_acorn_filename(de, tmpname, dir);
126 dpnt = tmpname;
127 } else if (sbi->s_mapping == 'n') {
128 dlen = isofs_name_translate(de, tmpname, dir);
129 dpnt = tmpname;
130 }
131
132
133
134
135
136 match = 0;
137 if (dlen > 0 &&
138 (sbi->s_hide =='n' ||
139 (!(de->flags[-sbi->s_high_sierra] & 1))) &&
140 (sbi->s_showassoc =='y' ||
141 (!(de->flags[-sbi->s_high_sierra] & 4)))) {
142 match = (isofs_cmp(dentry, dpnt, dlen) == 0);
143 }
144 if (match) {
145 isofs_normalize_block_and_offset(de,
146 &block_saved,
147 &offset_saved);
148 *block_rv = block_saved;
149 *offset_rv = offset_saved;
150 brelse(bh);
151 return 1;
152 }
153 }
154 brelse(bh);
155 return 0;
156}
157
158struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
159{
160 int found;
161 unsigned long uninitialized_var(block);
162 unsigned long uninitialized_var(offset);
163 struct inode *inode;
164 struct page *page;
165
166 dentry->d_op = dir->i_sb->s_root->d_op;
167
168 page = alloc_page(GFP_USER);
169 if (!page)
170 return ERR_PTR(-ENOMEM);
171
172 lock_kernel();
173 found = isofs_find_entry(dir, dentry,
174 &block, &offset,
175 page_address(page),
176 1024 + page_address(page));
177 __free_page(page);
178
179 inode = NULL;
180 if (found) {
181 inode = isofs_iget(dir->i_sb, block, offset);
182 if (!inode) {
183 unlock_kernel();
184 return ERR_PTR(-EACCES);
185 }
186 }
187 unlock_kernel();
188 return d_splice_alias(inode, dentry);
189}
190
