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1da177e4 LT |
1 | /* |
2 | * linux/fs/isofs/dir.c | |
3 | * | |
4 | * (C) 1992, 1993, 1994 Eric Youngdale Modified for ISO 9660 filesystem. | |
5 | * | |
6 | * (C) 1991 Linus Torvalds - minix filesystem | |
7 | * | |
8 | * Steve Beynon : Missing last directory entries fixed | |
9 | * (stephen@askone.demon.co.uk) : 21st June 1996 | |
10 | * | |
11 | * isofs directory handling functions | |
12 | */ | |
1da177e4 LT |
13 | #include <linux/config.h> |
14 | #include <linux/smp_lock.h> | |
94f2f715 | 15 | #include "isofs.h" |
1da177e4 LT |
16 | |
17 | static int isofs_readdir(struct file *, void *, filldir_t); | |
18 | ||
19 | struct file_operations isofs_dir_operations = | |
20 | { | |
21 | .read = generic_read_dir, | |
22 | .readdir = isofs_readdir, | |
23 | }; | |
24 | ||
25 | /* | |
26 | * directories can handle most operations... | |
27 | */ | |
28 | struct inode_operations isofs_dir_inode_operations = | |
29 | { | |
30 | .lookup = isofs_lookup, | |
31 | }; | |
32 | ||
33 | int isofs_name_translate(struct iso_directory_record *de, char *new, struct inode *inode) | |
34 | { | |
35 | char * old = de->name; | |
36 | int len = de->name_len[0]; | |
37 | int i; | |
38 | ||
39 | for (i = 0; i < len; i++) { | |
40 | unsigned char c = old[i]; | |
41 | if (!c) | |
42 | break; | |
43 | ||
44 | if (c >= 'A' && c <= 'Z') | |
45 | c |= 0x20; /* lower case */ | |
46 | ||
47 | /* Drop trailing '.;1' (ISO 9660:1988 7.5.1 requires period) */ | |
48 | if (c == '.' && i == len - 3 && old[i + 1] == ';' && old[i + 2] == '1') | |
49 | break; | |
50 | ||
51 | /* Drop trailing ';1' */ | |
52 | if (c == ';' && i == len - 2 && old[i + 1] == '1') | |
53 | break; | |
54 | ||
55 | /* Convert remaining ';' to '.' */ | |
56 | /* Also '/' to '.' (broken Acorn-generated ISO9660 images) */ | |
57 | if (c == ';' || c == '/') | |
58 | c = '.'; | |
59 | ||
60 | new[i] = c; | |
61 | } | |
62 | return i; | |
63 | } | |
64 | ||
65 | /* Acorn extensions written by Matthew Wilcox <willy@bofh.ai> 1998 */ | |
66 | int get_acorn_filename(struct iso_directory_record * de, | |
67 | char * retname, struct inode * inode) | |
68 | { | |
69 | int std; | |
70 | unsigned char * chr; | |
71 | int retnamlen = isofs_name_translate(de, retname, inode); | |
72 | if (retnamlen == 0) return 0; | |
73 | std = sizeof(struct iso_directory_record) + de->name_len[0]; | |
74 | if (std & 1) std++; | |
75 | if ((*((unsigned char *) de) - std) != 32) return retnamlen; | |
76 | chr = ((unsigned char *) de) + std; | |
77 | if (strncmp(chr, "ARCHIMEDES", 10)) return retnamlen; | |
78 | if ((*retname == '_') && ((chr[19] & 1) == 1)) *retname = '!'; | |
79 | if (((de->flags[0] & 2) == 0) && (chr[13] == 0xff) | |
80 | && ((chr[12] & 0xf0) == 0xf0)) | |
81 | { | |
82 | retname[retnamlen] = ','; | |
83 | sprintf(retname+retnamlen+1, "%3.3x", | |
84 | ((chr[12] & 0xf) << 8) | chr[11]); | |
85 | retnamlen += 4; | |
86 | } | |
87 | return retnamlen; | |
88 | } | |
89 | ||
90 | /* | |
91 | * This should _really_ be cleaned up some day.. | |
92 | */ | |
93 | static int do_isofs_readdir(struct inode *inode, struct file *filp, | |
94 | void *dirent, filldir_t filldir, | |
95 | char * tmpname, struct iso_directory_record * tmpde) | |
96 | { | |
97 | unsigned long bufsize = ISOFS_BUFFER_SIZE(inode); | |
98 | unsigned char bufbits = ISOFS_BUFFER_BITS(inode); | |
99 | unsigned long block, offset, block_saved, offset_saved; | |
100 | unsigned long inode_number = 0; /* Quiet GCC */ | |
101 | struct buffer_head *bh = NULL; | |
102 | int len; | |
103 | int map; | |
104 | int first_de = 1; | |
105 | char *p = NULL; /* Quiet GCC */ | |
106 | struct iso_directory_record *de; | |
107 | struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb); | |
108 | ||
109 | offset = filp->f_pos & (bufsize - 1); | |
110 | block = filp->f_pos >> bufbits; | |
111 | ||
112 | while (filp->f_pos < inode->i_size) { | |
113 | int de_len; | |
114 | ||
115 | if (!bh) { | |
116 | bh = isofs_bread(inode, block); | |
117 | if (!bh) | |
118 | return 0; | |
119 | } | |
120 | ||
121 | de = (struct iso_directory_record *) (bh->b_data + offset); | |
122 | ||
123 | de_len = *(unsigned char *) de; | |
124 | ||
125 | /* If the length byte is zero, we should move on to the next | |
126 | CDROM sector. If we are at the end of the directory, we | |
127 | kick out of the while loop. */ | |
128 | ||
129 | if (de_len == 0) { | |
130 | brelse(bh); | |
131 | bh = NULL; | |
132 | filp->f_pos = (filp->f_pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1); | |
133 | block = filp->f_pos >> bufbits; | |
134 | offset = 0; | |
135 | continue; | |
136 | } | |
137 | ||
138 | block_saved = block; | |
139 | offset_saved = offset; | |
140 | offset += de_len; | |
141 | ||
142 | /* Make sure we have a full directory entry */ | |
143 | if (offset >= bufsize) { | |
144 | int slop = bufsize - offset + de_len; | |
145 | memcpy(tmpde, de, slop); | |
146 | offset &= bufsize - 1; | |
147 | block++; | |
148 | brelse(bh); | |
149 | bh = NULL; | |
150 | if (offset) { | |
151 | bh = isofs_bread(inode, block); | |
152 | if (!bh) | |
153 | return 0; | |
154 | memcpy((void *) tmpde + slop, bh->b_data, offset); | |
155 | } | |
156 | de = tmpde; | |
157 | } | |
158 | ||
159 | if (first_de) { | |
160 | isofs_normalize_block_and_offset(de, | |
161 | &block_saved, | |
162 | &offset_saved); | |
163 | inode_number = isofs_get_ino(block_saved, | |
164 | offset_saved, | |
165 | bufbits); | |
166 | } | |
167 | ||
168 | if (de->flags[-sbi->s_high_sierra] & 0x80) { | |
169 | first_de = 0; | |
170 | filp->f_pos += de_len; | |
171 | continue; | |
172 | } | |
173 | first_de = 1; | |
174 | ||
175 | /* Handle the case of the '.' directory */ | |
176 | if (de->name_len[0] == 1 && de->name[0] == 0) { | |
177 | if (filldir(dirent, ".", 1, filp->f_pos, inode->i_ino, DT_DIR) < 0) | |
178 | break; | |
179 | filp->f_pos += de_len; | |
180 | continue; | |
181 | } | |
182 | ||
183 | len = 0; | |
184 | ||
185 | /* Handle the case of the '..' directory */ | |
186 | if (de->name_len[0] == 1 && de->name[0] == 1) { | |
187 | inode_number = parent_ino(filp->f_dentry); | |
188 | if (filldir(dirent, "..", 2, filp->f_pos, inode_number, DT_DIR) < 0) | |
189 | break; | |
190 | filp->f_pos += de_len; | |
191 | continue; | |
192 | } | |
193 | ||
194 | /* Handle everything else. Do name translation if there | |
195 | is no Rock Ridge NM field. */ | |
9769f4eb JW |
196 | |
197 | /* | |
198 | * Do not report hidden files if so instructed, or associated | |
199 | * files unless instructed to do so | |
200 | */ | |
201 | if ((sbi->s_hide == 'y' && | |
202 | (de->flags[-sbi->s_high_sierra] & 1)) || | |
203 | (sbi->s_showassoc =='n' && | |
204 | (de->flags[-sbi->s_high_sierra] & 4))) { | |
205 | filp->f_pos += de_len; | |
206 | continue; | |
1da177e4 LT |
207 | } |
208 | ||
209 | map = 1; | |
210 | if (sbi->s_rock) { | |
211 | len = get_rock_ridge_filename(de, tmpname, inode); | |
212 | if (len != 0) { /* may be -1 */ | |
213 | p = tmpname; | |
214 | map = 0; | |
215 | } | |
216 | } | |
217 | if (map) { | |
218 | #ifdef CONFIG_JOLIET | |
219 | if (sbi->s_joliet_level) { | |
220 | len = get_joliet_filename(de, tmpname, inode); | |
221 | p = tmpname; | |
222 | } else | |
223 | #endif | |
224 | if (sbi->s_mapping == 'a') { | |
225 | len = get_acorn_filename(de, tmpname, inode); | |
226 | p = tmpname; | |
227 | } else | |
228 | if (sbi->s_mapping == 'n') { | |
229 | len = isofs_name_translate(de, tmpname, inode); | |
230 | p = tmpname; | |
231 | } else { | |
232 | p = de->name; | |
233 | len = de->name_len[0]; | |
234 | } | |
235 | } | |
236 | if (len > 0) { | |
237 | if (filldir(dirent, p, len, filp->f_pos, inode_number, DT_UNKNOWN) < 0) | |
238 | break; | |
239 | } | |
240 | filp->f_pos += de_len; | |
241 | ||
242 | continue; | |
243 | } | |
244 | if (bh) brelse(bh); | |
245 | return 0; | |
246 | } | |
247 | ||
248 | /* | |
249 | * Handle allocation of temporary space for name translation and | |
250 | * handling split directory entries.. The real work is done by | |
251 | * "do_isofs_readdir()". | |
252 | */ | |
253 | static int isofs_readdir(struct file *filp, | |
254 | void *dirent, filldir_t filldir) | |
255 | { | |
256 | int result; | |
257 | char * tmpname; | |
258 | struct iso_directory_record * tmpde; | |
259 | struct inode *inode = filp->f_dentry->d_inode; | |
260 | ||
261 | ||
262 | tmpname = (char *)__get_free_page(GFP_KERNEL); | |
263 | if (tmpname == NULL) | |
264 | return -ENOMEM; | |
265 | ||
266 | lock_kernel(); | |
267 | tmpde = (struct iso_directory_record *) (tmpname+1024); | |
268 | ||
269 | result = do_isofs_readdir(inode, filp, dirent, filldir, tmpname, tmpde); | |
270 | ||
271 | free_page((unsigned long) tmpname); | |
272 | unlock_kernel(); | |
273 | return result; | |
274 | } |