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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/isofs/namei.c | |
3 | * | |
4 | * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. | |
5 | * | |
6 | * (C) 1991 Linus Torvalds - minix filesystem | |
7 | */ | |
8 | ||
5a0e3ad6 | 9 | #include <linux/gfp.h> |
94f2f715 | 10 | #include "isofs.h" |
1da177e4 LT |
11 | |
12 | /* | |
13 | * ok, we cannot use strncmp, as the name is not in our data space. | |
14 | * Thus we'll have to use isofs_match. No big problem. Match also makes | |
15 | * some sanity tests. | |
16 | */ | |
17 | static int | |
c3ed85a3 | 18 | isofs_cmp(struct dentry *dentry, const char *compare, int dlen) |
1da177e4 LT |
19 | { |
20 | struct qstr qstr; | |
1da177e4 LT |
21 | qstr.name = compare; |
22 | qstr.len = dlen; | |
da53be12 | 23 | return dentry->d_op->d_compare(NULL, NULL, dentry->d_name.len, dentry->d_name.name, &qstr); |
1da177e4 LT |
24 | } |
25 | ||
26 | /* | |
27 | * isofs_find_entry() | |
28 | * | |
29 | * finds an entry in the specified directory with the wanted name. It | |
30 | * returns the inode number of the found entry, or 0 on error. | |
31 | */ | |
32 | static unsigned long | |
33 | isofs_find_entry(struct inode *dir, struct dentry *dentry, | |
c3ed85a3 DJ |
34 | unsigned long *block_rv, unsigned long *offset_rv, |
35 | char *tmpname, struct iso_directory_record *tmpde) | |
1da177e4 LT |
36 | { |
37 | unsigned long bufsize = ISOFS_BUFFER_SIZE(dir); | |
38 | unsigned char bufbits = ISOFS_BUFFER_BITS(dir); | |
39 | unsigned long block, f_pos, offset, block_saved, offset_saved; | |
c3ed85a3 | 40 | struct buffer_head *bh = NULL; |
1da177e4 LT |
41 | struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb); |
42 | ||
43 | if (!ISOFS_I(dir)->i_first_extent) | |
44 | return 0; | |
c3ed85a3 | 45 | |
1da177e4 LT |
46 | f_pos = 0; |
47 | offset = 0; | |
48 | block = 0; | |
49 | ||
50 | while (f_pos < dir->i_size) { | |
c3ed85a3 | 51 | struct iso_directory_record *de; |
1da177e4 LT |
52 | int de_len, match, i, dlen; |
53 | char *dpnt; | |
54 | ||
55 | if (!bh) { | |
56 | bh = isofs_bread(dir, block); | |
57 | if (!bh) | |
58 | return 0; | |
59 | } | |
60 | ||
61 | de = (struct iso_directory_record *) (bh->b_data + offset); | |
62 | ||
63 | de_len = *(unsigned char *) de; | |
64 | if (!de_len) { | |
65 | brelse(bh); | |
66 | bh = NULL; | |
67 | f_pos = (f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1); | |
68 | block = f_pos >> bufbits; | |
69 | offset = 0; | |
70 | continue; | |
71 | } | |
72 | ||
73 | block_saved = bh->b_blocknr; | |
74 | offset_saved = offset; | |
75 | offset += de_len; | |
76 | f_pos += de_len; | |
77 | ||
78 | /* Make sure we have a full directory entry */ | |
79 | if (offset >= bufsize) { | |
80 | int slop = bufsize - offset + de_len; | |
81 | memcpy(tmpde, de, slop); | |
82 | offset &= bufsize - 1; | |
83 | block++; | |
84 | brelse(bh); | |
85 | bh = NULL; | |
86 | if (offset) { | |
87 | bh = isofs_bread(dir, block); | |
88 | if (!bh) | |
89 | return 0; | |
90 | memcpy((void *) tmpde + slop, bh->b_data, offset); | |
91 | } | |
92 | de = tmpde; | |
93 | } | |
94 | ||
95 | dlen = de->name_len[0]; | |
96 | dpnt = de->name; | |
2deb1acc JK |
97 | /* Basic sanity check, whether name doesn't exceed dir entry */ |
98 | if (de_len < dlen + sizeof(struct iso_directory_record)) { | |
99 | printk(KERN_NOTICE "iso9660: Corrupted directory entry" | |
100 | " in block %lu of inode %lu\n", block, | |
101 | dir->i_ino); | |
102 | return 0; | |
103 | } | |
1da177e4 LT |
104 | |
105 | if (sbi->s_rock && | |
106 | ((i = get_rock_ridge_filename(de, tmpname, dir)))) { | |
c3ed85a3 | 107 | dlen = i; /* possibly -1 */ |
1da177e4 LT |
108 | dpnt = tmpname; |
109 | #ifdef CONFIG_JOLIET | |
110 | } else if (sbi->s_joliet_level) { | |
111 | dlen = get_joliet_filename(de, tmpname, dir); | |
112 | dpnt = tmpname; | |
113 | #endif | |
114 | } else if (sbi->s_mapping == 'a') { | |
115 | dlen = get_acorn_filename(de, tmpname, dir); | |
116 | dpnt = tmpname; | |
117 | } else if (sbi->s_mapping == 'n') { | |
118 | dlen = isofs_name_translate(de, tmpname, dir); | |
119 | dpnt = tmpname; | |
120 | } | |
121 | ||
122 | /* | |
9769f4eb JW |
123 | * Skip hidden or associated files unless hide or showassoc, |
124 | * respectively, is set | |
1da177e4 LT |
125 | */ |
126 | match = 0; | |
127 | if (dlen > 0 && | |
5404ac8e | 128 | (!sbi->s_hide || |
9769f4eb | 129 | (!(de->flags[-sbi->s_high_sierra] & 1))) && |
5404ac8e | 130 | (sbi->s_showassoc || |
9769f4eb | 131 | (!(de->flags[-sbi->s_high_sierra] & 4)))) { |
f643ff55 AV |
132 | if (dpnt && (dlen > 1 || dpnt[0] > 1)) |
133 | match = (isofs_cmp(dentry, dpnt, dlen) == 0); | |
1da177e4 LT |
134 | } |
135 | if (match) { | |
136 | isofs_normalize_block_and_offset(de, | |
137 | &block_saved, | |
138 | &offset_saved); | |
c3ed85a3 DJ |
139 | *block_rv = block_saved; |
140 | *offset_rv = offset_saved; | |
9769f4eb | 141 | brelse(bh); |
1da177e4 LT |
142 | return 1; |
143 | } | |
144 | } | |
9769f4eb | 145 | brelse(bh); |
1da177e4 LT |
146 | return 0; |
147 | } | |
148 | ||
00cd8dd3 | 149 | struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
1da177e4 LT |
150 | { |
151 | int found; | |
cd215237 BP |
152 | unsigned long uninitialized_var(block); |
153 | unsigned long uninitialized_var(offset); | |
1da177e4 LT |
154 | struct inode *inode; |
155 | struct page *page; | |
156 | ||
1da177e4 LT |
157 | page = alloc_page(GFP_USER); |
158 | if (!page) | |
159 | return ERR_PTR(-ENOMEM); | |
160 | ||
1da177e4 | 161 | found = isofs_find_entry(dir, dentry, |
c3ed85a3 DJ |
162 | &block, &offset, |
163 | page_address(page), | |
164 | 1024 + page_address(page)); | |
1da177e4 LT |
165 | __free_page(page); |
166 | ||
a9049376 AV |
167 | inode = found ? isofs_iget(dir->i_sb, block, offset) : NULL; |
168 | ||
2ff6b1c2 | 169 | return d_splice_alias(inode, dentry); |
1da177e4 | 170 | } |