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*/
1 /*
2 * linux/fs/isofs/dir.c
3 *
4 * (C) 1992, 1993, 1994 Eric Youngdale Modified for ISO9660 filesystem.
5 *
6 * (C) 1991 Linus Torvalds - minix filesystem
7 *
8 * isofs directory handling functions
9 */
10
11 #include <linux/errno.h>
12
13 #include <asm/segment.h>
14
15 #include <linux/fs.h>
16 #include <linux/iso_fs.h>
17 #include <linux/kernel.h>
18 #include <linux/stat.h>
19 #include <linux/string.h>
20 #include <linux/mm.h>
21 #include <linux/malloc.h>
22 #include <linux/sched.h>
23 #include <linux/locks.h>
24
25 #define NAME_OFFSET(de) ((int) ((de)->d_name - (char *) (de)))
26 #define ROUND_UP(x) (((x)+3) & ~3)
27
28 static int isofs_readdir(struct inode *, struct file *, struct dirent *, int);
29
30 static struct file_operations isofs_dir_operations = {
31 NULL, /* lseek - default */
32 NULL, /* read */
33 NULL, /* write - bad */
34 isofs_readdir, /* readdir */
35 NULL, /* select - default */
36 NULL, /* ioctl - default */
37 NULL, /* no special open code */
38 NULL, /* no special release code */
39 NULL /* fsync */
40 };
41
42 /*
43 * directories can handle most operations...
44 */
45 struct inode_operations isofs_dir_inode_operations = {
46 &isofs_dir_operations, /* default directory file-ops */
47 NULL, /* create */
48 isofs_lookup, /* lookup */
49 NULL, /* link */
50 NULL, /* unlink */
51 NULL, /* symlink */
52 NULL, /* mkdir */
53 NULL, /* rmdir */
54 NULL, /* mknod */
55 NULL, /* rename */
56 NULL, /* readlink */
57 NULL, /* follow_link */
58 isofs_bmap, /* bmap */
59 NULL, /* truncate */
60 NULL /* permission */
61 };
62
63 static int isofs_readdir(struct inode * inode, struct file * filp,
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*/
64 struct dirent * dirent, int count)
65 {
66 unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
67 unsigned char bufbits = ISOFS_BUFFER_BITS(inode);
68 unsigned int block,offset,i, j;
69 char c = 0;
70 int inode_number;
71 struct buffer_head * bh;
72 void * cpnt = NULL;
73 unsigned int old_offset;
74 int dlen, rrflag;
75 int high_sierra = 0;
76 char * dpnt, *dpnt1;
77 struct iso_directory_record * de;
78
79 dpnt1 = NULL;
80 if (!inode || !S_ISDIR(inode->i_mode))
81 return -EBADF;
82
83 offset = filp->f_pos & (bufsize - 1);
84 block = isofs_bmap(inode,filp->f_pos>>bufbits);
85
86 if(!block) return 0;
87
88 if(!(bh = breada(inode->i_dev, block, bufsize, filp->f_pos, inode->i_size)))
89 return 0;
90
91 while (filp->f_pos < inode->i_size) {
92 #ifdef DEBUG
93 printk("Block, offset, f_pos: %x %x %x\n",
94 block, offset, filp->f_pos);
95 #endif
96 de = (struct iso_directory_record *) (bh->b_data + offset);
97 inode_number = (block << bufbits) + (offset & (bufsize - 1));
98
99 /* If the length byte is zero, we should move on to the next
100 CDROM sector. If we are at the end of the directory, we
101 kick out of the while loop. */
102
103 if (*((unsigned char *) de) == 0) {
104 brelse(bh);
105 offset = 0;
106 filp->f_pos = ((filp->f_pos & ~(ISOFS_BLOCK_SIZE - 1))
107 + ISOFS_BLOCK_SIZE);
108 block = isofs_bmap(inode,(filp->f_pos)>>bufbits);
109 if (!block
110 || !(bh = breada(inode->i_dev, block, bufsize, filp->f_pos,
111 inode->i_size)))
112 return 0;
113 continue;
114 }
115
116 /* Make sure that the entire directory record is in the
117 current bh block.
118 If not, we malloc a buffer, and put the two halves together,
119 so that we can cleanly read the block */
120
121 old_offset = offset;
122 offset += *((unsigned char *) de);
123 filp->f_pos += *((unsigned char *) de);
124
125 if (offset > bufsize) {
126 unsigned int frag1;
127 frag1 = bufsize - old_offset;
128 cpnt = kmalloc(*((unsigned char *) de),GFP_KERNEL);
129 if (!cpnt) return 0;
130 memcpy(cpnt, bh->b_data + old_offset, frag1);
131 de = (struct iso_directory_record *) ((char *)cpnt);
132 brelse(bh);
133 offset = filp->f_pos & (bufsize - 1);
134 block = isofs_bmap(inode,(filp->f_pos)>> bufbits);
135 if (!block
136 || !(bh = breada(inode->i_dev, block, bufsize,
137 filp->f_pos, inode->i_size))) {
138 kfree(cpnt);
139 return 0;
140 };
141 memcpy((char *)cpnt+frag1, bh->b_data, offset);
142 }
143
144 /* Handle the case of the '.' directory */
145
146 rrflag = 0;
147 i = 1;
148 if (de->name_len[0] == 1 && de->name[0] == 0) {
149 put_fs_byte('.',dirent->d_name);
150 inode_number = inode->i_ino;
151 dpnt = ".";
152 }
153
154 /* Handle the case of the '..' directory */
155
156 else if (de->name_len[0] == 1 && de->name[0] == 1) {
157 put_fs_byte('.',dirent->d_name);
158 put_fs_byte('.',dirent->d_name+1);
159 i = 2;
160 dpnt = "..";
161 if((inode->i_sb->u.isofs_sb.s_firstdatazone) != inode->i_ino)
162 inode_number = inode->u.isofs_i.i_backlink;
163 else
164 inode_number = inode->i_ino;
165
166 /* This should never happen, but who knows. Try to be forgiving */
167 if(inode_number == -1) {
168 inode_number =
169 isofs_lookup_grandparent(inode,
170 find_rock_ridge_relocation(de, inode));
171 if(inode_number == -1){ /* Should never happen */
172 printk("Backlink not properly set.\n");
173 goto out;
174 };
175 }
176 }
177
178 /* Handle everything else. Do name translation if there
179 is no Rock Ridge NM field. */
180
181 else {
182 /* Do not report hidden or associated files */
183 high_sierra = inode->i_sb->u.isofs_sb.s_high_sierra;
184 if (de->flags[-high_sierra] & 5) {
185 if (cpnt) {
186 kfree(cpnt);
187 cpnt = NULL;
188 };
189 continue;
190 }
191 dlen = de->name_len[0];
192 dpnt = de->name;
193 i = dlen;
194 rrflag = get_rock_ridge_filename(de, &dpnt, &dlen, inode);
195 if (rrflag) {
196 if (rrflag == -1) { /* This is a rock ridge reloc dir */
197 if (cpnt) {
198 kfree(cpnt);
199 cpnt = NULL;
200 };
201 continue;
202 };
203 i = dlen;
204 }
205 else
206 if(inode->i_sb->u.isofs_sb.s_mapping == 'n') {
207 dpnt1 = dpnt;
208 dpnt = kmalloc(dlen, GFP_KERNEL);
209 if (!dpnt) goto out;
210 for (i = 0; i < dlen && i < NAME_MAX; i++) {
211 if (!(c = dpnt1[i])) break;
212 if (c >= 'A' && c <= 'Z') c |= 0x20; /* lower case */
213 if (c == '.' && i == dlen-3 && de->name[i+1] == ';' && de->name[i+2] == '1')
214 break; /* Drop trailing '.;1' (ISO9660:1988 7.5.1 requires period) */
215 if (c == ';' && i == dlen-2 && de->name[i+1] == '1')
216 break; /* Drop trailing ';1' */
217 if (c == ';') c = '.'; /* Convert remaining ';' to '.' */
218 dpnt[i] = c;
219 }
220 }
221 for(j=0; j<i; j++)
222 put_fs_byte(dpnt[j],j+dirent->d_name); /* And save it */
223 if(dpnt1) {
224 kfree(dpnt);
225 dpnt = dpnt1;
226 }
227
228 dcache_add(inode, dpnt, i, inode_number);
229 };
230 #if 0
231 printk("Nchar: %d\n",i);
232 #endif
233
234 if (rrflag) kfree(dpnt);
235 if (cpnt) {
236 kfree(cpnt);
237 cpnt = NULL;
238 };
239
240 if (i) {
241 put_fs_long(inode_number, &dirent->d_ino);
242 put_fs_byte(0,i+dirent->d_name);
243 put_fs_word(i,&dirent->d_reclen);
244 brelse(bh);
245 return ROUND_UP(NAME_OFFSET(dirent) + i + 1);
246 }
247 }
248 /* We go here for any condition we cannot handle. We also drop through
249 to here at the end of the directory. */
250 out:
251 if (cpnt)
252 kfree(cpnt);
253 brelse(bh);
254 return 0;
255 }
256
257
258
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*/