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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Dave Jonesc3ed85a2007-07-15 23:40:03 -070010 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 * isofs directory handling functions
12 */
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090013#include <linux/gfp.h>
Al Viro94f2f7152005-04-25 18:32:12 -070014#include "isofs.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070015
Linus Torvalds1da177e2005-04-16 15:20:36 -070016int isofs_name_translate(struct iso_directory_record *de, char *new, struct inode *inode)
17{
18 char * old = de->name;
19 int len = de->name_len[0];
20 int i;
Dave Jonesc3ed85a2007-07-15 23:40:03 -070021
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 for (i = 0; i < len; i++) {
23 unsigned char c = old[i];
24 if (!c)
25 break;
26
27 if (c >= 'A' && c <= 'Z')
28 c |= 0x20; /* lower case */
29
30 /* Drop trailing '.;1' (ISO 9660:1988 7.5.1 requires period) */
31 if (c == '.' && i == len - 3 && old[i + 1] == ';' && old[i + 2] == '1')
32 break;
33
34 /* Drop trailing ';1' */
35 if (c == ';' && i == len - 2 && old[i + 1] == '1')
36 break;
37
38 /* Convert remaining ';' to '.' */
39 /* Also '/' to '.' (broken Acorn-generated ISO9660 images) */
40 if (c == ';' || c == '/')
41 c = '.';
42
43 new[i] = c;
44 }
45 return i;
46}
47
48/* Acorn extensions written by Matthew Wilcox <willy@bofh.ai> 1998 */
Dave Jonesc3ed85a2007-07-15 23:40:03 -070049int get_acorn_filename(struct iso_directory_record *de,
50 char *retname, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -070051{
52 int std;
Dave Jonesc3ed85a2007-07-15 23:40:03 -070053 unsigned char *chr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 int retnamlen = isofs_name_translate(de, retname, inode);
Dave Jonesc3ed85a2007-07-15 23:40:03 -070055
56 if (retnamlen == 0)
57 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 std = sizeof(struct iso_directory_record) + de->name_len[0];
Dave Jonesc3ed85a2007-07-15 23:40:03 -070059 if (std & 1)
60 std++;
61 if ((*((unsigned char *) de) - std) != 32)
62 return retnamlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 chr = ((unsigned char *) de) + std;
Dave Jonesc3ed85a2007-07-15 23:40:03 -070064 if (strncmp(chr, "ARCHIMEDES", 10))
65 return retnamlen;
66 if ((*retname == '_') && ((chr[19] & 1) == 1))
67 *retname = '!';
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 if (((de->flags[0] & 2) == 0) && (chr[13] == 0xff)
Dave Jonesc3ed85a2007-07-15 23:40:03 -070069 && ((chr[12] & 0xf0) == 0xf0)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 retname[retnamlen] = ',';
71 sprintf(retname+retnamlen+1, "%3.3x",
72 ((chr[12] & 0xf) << 8) | chr[11]);
73 retnamlen += 4;
74 }
75 return retnamlen;
76}
77
78/*
79 * This should _really_ be cleaned up some day..
80 */
Al Virobfee7162013-05-17 21:11:59 -040081static int do_isofs_readdir(struct inode *inode, struct file *file,
82 struct dir_context *ctx,
Dave Jonesc3ed85a2007-07-15 23:40:03 -070083 char *tmpname, struct iso_directory_record *tmpde)
Linus Torvalds1da177e2005-04-16 15:20:36 -070084{
85 unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
86 unsigned char bufbits = ISOFS_BUFFER_BITS(inode);
87 unsigned long block, offset, block_saved, offset_saved;
88 unsigned long inode_number = 0; /* Quiet GCC */
89 struct buffer_head *bh = NULL;
90 int len;
91 int map;
92 int first_de = 1;
93 char *p = NULL; /* Quiet GCC */
94 struct iso_directory_record *de;
95 struct isofs_sb_info *sbi = ISOFS_SB(inode->i_sb);
96
Al Virobfee7162013-05-17 21:11:59 -040097 offset = ctx->pos & (bufsize - 1);
98 block = ctx->pos >> bufbits;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
Al Virobfee7162013-05-17 21:11:59 -0400100 while (ctx->pos < inode->i_size) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 int de_len;
102
103 if (!bh) {
104 bh = isofs_bread(inode, block);
105 if (!bh)
106 return 0;
107 }
108
109 de = (struct iso_directory_record *) (bh->b_data + offset);
110
Al Virobfee7162013-05-17 21:11:59 -0400111 de_len = *(unsigned char *)de;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700113 /*
114 * If the length byte is zero, we should move on to the next
115 * CDROM sector. If we are at the end of the directory, we
116 * kick out of the while loop.
117 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
119 if (de_len == 0) {
120 brelse(bh);
121 bh = NULL;
Al Virobfee7162013-05-17 21:11:59 -0400122 ctx->pos = (ctx->pos + ISOFS_BLOCK_SIZE) & ~(ISOFS_BLOCK_SIZE - 1);
123 block = ctx->pos >> bufbits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 offset = 0;
125 continue;
126 }
127
128 block_saved = block;
129 offset_saved = offset;
130 offset += de_len;
131
132 /* Make sure we have a full directory entry */
133 if (offset >= bufsize) {
134 int slop = bufsize - offset + de_len;
135 memcpy(tmpde, de, slop);
136 offset &= bufsize - 1;
137 block++;
138 brelse(bh);
139 bh = NULL;
140 if (offset) {
141 bh = isofs_bread(inode, block);
142 if (!bh)
143 return 0;
144 memcpy((void *) tmpde + slop, bh->b_data, offset);
145 }
146 de = tmpde;
147 }
Jan Kara2deb1ac2008-04-30 00:52:33 -0700148 /* Basic sanity check, whether name doesn't exceed dir entry */
149 if (de_len < de->name_len[0] +
150 sizeof(struct iso_directory_record)) {
151 printk(KERN_NOTICE "iso9660: Corrupted directory entry"
152 " in block %lu of inode %lu\n", block,
153 inode->i_ino);
154 return -EIO;
155 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
157 if (first_de) {
158 isofs_normalize_block_and_offset(de,
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700159 &block_saved,
160 &offset_saved);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 inode_number = isofs_get_ino(block_saved,
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700162 offset_saved, bufbits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 }
164
165 if (de->flags[-sbi->s_high_sierra] & 0x80) {
166 first_de = 0;
Al Virobfee7162013-05-17 21:11:59 -0400167 ctx->pos += de_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 continue;
169 }
170 first_de = 1;
171
172 /* Handle the case of the '.' directory */
173 if (de->name_len[0] == 1 && de->name[0] == 0) {
Al Virobfee7162013-05-17 21:11:59 -0400174 if (!dir_emit_dot(file, ctx))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 break;
Al Virobfee7162013-05-17 21:11:59 -0400176 ctx->pos += de_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 continue;
178 }
179
180 len = 0;
181
182 /* Handle the case of the '..' directory */
183 if (de->name_len[0] == 1 && de->name[0] == 1) {
Al Virobfee7162013-05-17 21:11:59 -0400184 if (!dir_emit_dotdot(file, ctx))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 break;
Al Virobfee7162013-05-17 21:11:59 -0400186 ctx->pos += de_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 continue;
188 }
189
190 /* Handle everything else. Do name translation if there
191 is no Rock Ridge NM field. */
Jeremy White9769f4e2005-06-21 17:16:53 -0700192
193 /*
194 * Do not report hidden files if so instructed, or associated
195 * files unless instructed to do so
196 */
Jan Kara5404ac82009-06-17 16:26:27 -0700197 if ((sbi->s_hide && (de->flags[-sbi->s_high_sierra] & 1)) ||
198 (!sbi->s_showassoc &&
Jeremy White9769f4e2005-06-21 17:16:53 -0700199 (de->flags[-sbi->s_high_sierra] & 4))) {
Al Virobfee7162013-05-17 21:11:59 -0400200 ctx->pos += de_len;
Jeremy White9769f4e2005-06-21 17:16:53 -0700201 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 }
203
204 map = 1;
205 if (sbi->s_rock) {
206 len = get_rock_ridge_filename(de, tmpname, inode);
207 if (len != 0) { /* may be -1 */
208 p = tmpname;
209 map = 0;
210 }
211 }
212 if (map) {
213#ifdef CONFIG_JOLIET
214 if (sbi->s_joliet_level) {
215 len = get_joliet_filename(de, tmpname, inode);
216 p = tmpname;
217 } else
218#endif
219 if (sbi->s_mapping == 'a') {
220 len = get_acorn_filename(de, tmpname, inode);
221 p = tmpname;
222 } else
223 if (sbi->s_mapping == 'n') {
224 len = isofs_name_translate(de, tmpname, inode);
225 p = tmpname;
226 } else {
227 p = de->name;
228 len = de->name_len[0];
229 }
230 }
231 if (len > 0) {
Al Virobfee7162013-05-17 21:11:59 -0400232 if (!dir_emit(ctx, p, len, inode_number, DT_UNKNOWN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 break;
234 }
Al Virobfee7162013-05-17 21:11:59 -0400235 ctx->pos += de_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
237 continue;
238 }
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700239 if (bh)
240 brelse(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 return 0;
242}
243
244/*
245 * Handle allocation of temporary space for name translation and
246 * handling split directory entries.. The real work is done by
247 * "do_isofs_readdir()".
248 */
Al Virobfee7162013-05-17 21:11:59 -0400249static int isofs_readdir(struct file *file, struct dir_context *ctx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250{
251 int result;
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700252 char *tmpname;
253 struct iso_directory_record *tmpde;
Al Virobfee7162013-05-17 21:11:59 -0400254 struct inode *inode = file_inode(file);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 tmpname = (char *)__get_free_page(GFP_KERNEL);
257 if (tmpname == NULL)
258 return -ENOMEM;
259
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 tmpde = (struct iso_directory_record *) (tmpname+1024);
261
Al Virobfee7162013-05-17 21:11:59 -0400262 result = do_isofs_readdir(inode, file, ctx, tmpname, tmpde);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
264 free_page((unsigned long) tmpname);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265 return result;
266}
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700267
268const struct file_operations isofs_dir_operations =
269{
jan Blunckca572722010-05-26 14:44:53 -0700270 .llseek = generic_file_llseek,
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700271 .read = generic_read_dir,
Al Virobfee7162013-05-17 21:11:59 -0400272 .iterate = isofs_readdir,
Dave Jonesc3ed85a2007-07-15 23:40:03 -0700273};
274
275/*
276 * directories can handle most operations...
277 */
278const struct inode_operations isofs_dir_inode_operations =
279{
280 .lookup = isofs_lookup,
281};
282
283