Commit | Line | Data |
---|---|---|
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; | |
21 | ||
22 | if (!compare) | |
23 | return 1; | |
24 | ||
25 | /* check special "." and ".." files */ | |
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; | |
621e155a NP |
40 | return dentry->d_op->d_compare(NULL, NULL, NULL, NULL, |
41 | dentry->d_name.len, dentry->d_name.name, &qstr); | |
1da177e4 LT |
42 | } |
43 | ||
44 | /* | |
45 | * isofs_find_entry() | |
46 | * | |
47 | * finds an entry in the specified directory with the wanted name. It | |
48 | * returns the inode number of the found entry, or 0 on error. | |
49 | */ | |
50 | static unsigned long | |
51 | isofs_find_entry(struct inode *dir, struct dentry *dentry, | |
c3ed85a3 DJ |
52 | unsigned long *block_rv, unsigned long *offset_rv, |
53 | char *tmpname, struct iso_directory_record *tmpde) | |
1da177e4 LT |
54 | { |
55 | unsigned long bufsize = ISOFS_BUFFER_SIZE(dir); | |
56 | unsigned char bufbits = ISOFS_BUFFER_BITS(dir); | |
57 | unsigned long block, f_pos, offset, block_saved, offset_saved; | |
c3ed85a3 | 58 | struct buffer_head *bh = NULL; |
1da177e4 LT |
59 | struct isofs_sb_info *sbi = ISOFS_SB(dir->i_sb); |
60 | ||
61 | if (!ISOFS_I(dir)->i_first_extent) | |
62 | return 0; | |
c3ed85a3 | 63 | |
1da177e4 LT |
64 | f_pos = 0; |
65 | offset = 0; | |
66 | block = 0; | |
67 | ||
68 | while (f_pos < dir->i_size) { | |
c3ed85a3 | 69 | struct iso_directory_record *de; |
1da177e4 LT |
70 | int de_len, match, i, dlen; |
71 | char *dpnt; | |
72 | ||
73 | if (!bh) { | |
74 | bh = isofs_bread(dir, block); | |
75 | if (!bh) | |
76 | return 0; | |
77 | } | |
78 | ||
79 | de = (struct iso_directory_record *) (bh->b_data + offset); | |
80 | ||
81 | de_len = *(unsigned char *) de; | |
82 | if (!de_len) { | |
83 | brelse(bh); | |
84 | bh = NULL; | |
85 | f_pos = (f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1); | |
86 | block = f_pos >> bufbits; | |
87 | offset = 0; | |
88 | continue; | |
89 | } | |
90 | ||
91 | block_saved = bh->b_blocknr; | |
92 | offset_saved = offset; | |
93 | offset += de_len; | |
94 | f_pos += de_len; | |
95 | ||
96 | /* Make sure we have a full directory entry */ | |
97 | if (offset >= bufsize) { | |
98 | int slop = bufsize - offset + de_len; | |
99 | memcpy(tmpde, de, slop); | |
100 | offset &= bufsize - 1; | |
101 | block++; | |
102 | brelse(bh); | |
103 | bh = NULL; | |
104 | if (offset) { | |
105 | bh = isofs_bread(dir, block); | |
106 | if (!bh) | |
107 | return 0; | |
108 | memcpy((void *) tmpde + slop, bh->b_data, offset); | |
109 | } | |
110 | de = tmpde; | |
111 | } | |
112 | ||
113 | dlen = de->name_len[0]; | |
114 | dpnt = de->name; | |
2deb1acc JK |
115 | /* Basic sanity check, whether name doesn't exceed dir entry */ |
116 | if (de_len < dlen + sizeof(struct iso_directory_record)) { | |
117 | printk(KERN_NOTICE "iso9660: Corrupted directory entry" | |
118 | " in block %lu of inode %lu\n", block, | |
119 | dir->i_ino); | |
120 | return 0; | |
121 | } | |
1da177e4 LT |
122 | |
123 | if (sbi->s_rock && | |
124 | ((i = get_rock_ridge_filename(de, tmpname, dir)))) { | |
c3ed85a3 | 125 | dlen = i; /* possibly -1 */ |
1da177e4 LT |
126 | dpnt = tmpname; |
127 | #ifdef CONFIG_JOLIET | |
128 | } else if (sbi->s_joliet_level) { | |
129 | dlen = get_joliet_filename(de, tmpname, dir); | |
130 | dpnt = tmpname; | |
131 | #endif | |
132 | } else if (sbi->s_mapping == 'a') { | |
133 | dlen = get_acorn_filename(de, tmpname, dir); | |
134 | dpnt = tmpname; | |
135 | } else if (sbi->s_mapping == 'n') { | |
136 | dlen = isofs_name_translate(de, tmpname, dir); | |
137 | dpnt = tmpname; | |
138 | } | |
139 | ||
140 | /* | |
9769f4eb JW |
141 | * Skip hidden or associated files unless hide or showassoc, |
142 | * respectively, is set | |
1da177e4 LT |
143 | */ |
144 | match = 0; | |
145 | if (dlen > 0 && | |
5404ac8e | 146 | (!sbi->s_hide || |
9769f4eb | 147 | (!(de->flags[-sbi->s_high_sierra] & 1))) && |
5404ac8e | 148 | (sbi->s_showassoc || |
9769f4eb JW |
149 | (!(de->flags[-sbi->s_high_sierra] & 4)))) { |
150 | match = (isofs_cmp(dentry, dpnt, dlen) == 0); | |
1da177e4 LT |
151 | } |
152 | if (match) { | |
153 | isofs_normalize_block_and_offset(de, | |
154 | &block_saved, | |
155 | &offset_saved); | |
c3ed85a3 DJ |
156 | *block_rv = block_saved; |
157 | *offset_rv = offset_saved; | |
9769f4eb | 158 | brelse(bh); |
1da177e4 LT |
159 | return 1; |
160 | } | |
161 | } | |
9769f4eb | 162 | brelse(bh); |
1da177e4 LT |
163 | return 0; |
164 | } | |
165 | ||
00cd8dd3 | 166 | struct dentry *isofs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
1da177e4 LT |
167 | { |
168 | int found; | |
cd215237 BP |
169 | unsigned long uninitialized_var(block); |
170 | unsigned long uninitialized_var(offset); | |
1da177e4 LT |
171 | struct inode *inode; |
172 | struct page *page; | |
173 | ||
1da177e4 LT |
174 | page = alloc_page(GFP_USER); |
175 | if (!page) | |
176 | return ERR_PTR(-ENOMEM); | |
177 | ||
1da177e4 | 178 | found = isofs_find_entry(dir, dentry, |
c3ed85a3 DJ |
179 | &block, &offset, |
180 | page_address(page), | |
181 | 1024 + page_address(page)); | |
1da177e4 LT |
182 | __free_page(page); |
183 | ||
a9049376 AV |
184 | inode = found ? isofs_iget(dir->i_sb, block, offset) : NULL; |
185 | ||
2ff6b1c2 | 186 | return d_splice_alias(inode, dentry); |
1da177e4 | 187 | } |