![[first]](../icons/first.png){kind=icon}
![[previous]](../icons/n_left.png){kind=icon}
![[next]](../icons/n_right.png){kind=icon}
![[last]](../icons/n_last.png){kind=icon}
![[top]](../icons/n_top.png){kind=icon}
![[bottom]](../icons/bottom.png){kind=icon}
![[index]](../icons/index.png){kind=icon}
![[help]](../icons/help.png){kind=icon}
*/
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,
/* ![[first]](../icons/n_first.png)
![[top]](../icons/top.png)
*/
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 char * dpnt, *dpnt1;
76 struct iso_directory_record * de;
77
78 dpnt1 = NULL;
79 if (!inode || !S_ISDIR(inode->i_mode))
80 return -EBADF;
81
82 offset = filp->f_pos & (bufsize - 1);
83 block = isofs_bmap(inode,filp->f_pos>>bufbits);
84
85 if(!block) return 0;
86
87 if(!(bh = breada(inode->i_dev, block, bufsize, filp->f_pos, inode->i_size)))
88 return 0;
89
90 while (filp->f_pos < inode->i_size) {
91 #ifdef DEBUG
92 printk("Block, offset: %x %x %x\n",
93 block, offset, filp->f_pos);
94 #endif
95 de = (struct iso_directory_record *) (bh->b_data + offset);
96 inode_number = (block << bufbits) + (offset & (bufsize - 1));
97
98 /* If the length byte is zero, we should move on to the next
99 CDROM sector. If we are at the end of the directory, we
100 kick out of the while loop. */
101
102 if (*((unsigned char *) de) == 0) {
103 brelse(bh);
104 offset = 0;
105 filp->f_pos = ((filp->f_pos & ~(ISOFS_BLOCK_SIZE - 1))
106 + ISOFS_BLOCK_SIZE);
107 block = isofs_bmap(inode,(filp->f_pos)>>bufbits);
108 if (!block
109 || !(bh = breada(inode->i_dev, block, bufsize, filp->f_pos,
110 inode->i_size)))
111 return 0;
112 continue;
113 }
114
115 /* Make sure that the entire directory record is in the
116 current bh block.
117 If not, we malloc a buffer, and put the two halves together,
118 so that we can cleanly read the block */
119
120 old_offset = offset;
121 offset += *((unsigned char *) de);
122 filp->f_pos += *((unsigned char *) de);
123
124 if (offset >= bufsize) {
125 unsigned int frag1;
126 frag1 = bufsize - old_offset;
127 cpnt = kmalloc(*((unsigned char *) de),GFP_KERNEL);
128 memcpy(cpnt, bh->b_data + old_offset, frag1);
129 de = (struct iso_directory_record *) ((char *)cpnt);
130 brelse(bh);
131 offset = filp->f_pos & (bufsize - 1);
132 block = isofs_bmap(inode,(filp->f_pos)>> bufbits);
133 if (!block
134 || !(bh = breada(inode->i_dev, block, bufsize,
135 filp->f_pos, inode->i_size))) {
136 kfree(cpnt);
137 return 0;
138 };
139 memcpy((char *)cpnt+frag1, bh->b_data, offset);
140 }
141
142 /* Handle the case of the '.' directory */
143
144 rrflag = 0;
145 i = 1;
146 if (de->name_len[0] == 1 && de->name[0] == 0) {
147 put_fs_byte('.',dirent->d_name);
148 inode_number = inode->i_ino;
149 dpnt = ".";
150 }
151
152 /* Handle the case of the '..' directory */
153
154 else if (de->name_len[0] == 1 && de->name[0] == 1) {
155 put_fs_byte('.',dirent->d_name);
156 put_fs_byte('.',dirent->d_name+1);
157 i = 2;
158 dpnt = "..";
159 if((inode->i_sb->u.isofs_sb.s_firstdatazone
160 << bufbits) != inode->i_ino)
161 inode_number = inode->u.isofs_i.i_backlink;
162 else
163 inode_number = inode->i_ino;
164
165 /* This should never happen, but who knows. Try to be forgiving */
166 if(inode_number == -1) {
167 inode_number =
168 isofs_lookup_grandparent(inode,
169 find_rock_ridge_relocation(de, inode));
170 if(inode_number == -1){ /* Should never happen */
171 printk("Backlink not properly set.\n");
172 goto out;
173 };
174 }
175 }
176
177 /* Handle everything else. Do name translation if there
178 is no Rock Ridge NM field. */
179
180 else {
181 dlen = de->name_len[0];
182 dpnt = de->name;
183 i = dlen;
184 rrflag = get_rock_ridge_filename(de, &dpnt, &dlen, inode);
185 if (rrflag) {
186 if (rrflag == -1) { /* This is a rock ridge reloc dir */
187 if (cpnt) {
188 kfree(cpnt);
189 cpnt = NULL;
190 };
191 continue;
192 };
193 i = dlen;
194 }
195 else
196 if(inode->i_sb->u.isofs_sb.s_mapping == 'n') {
197 dpnt1 = dpnt;
198 dpnt = kmalloc(dlen, GFP_KERNEL);
199 for (i = 0; i < dlen && i < NAME_MAX; i++) {
200 if (!(c = dpnt1[i])) break;
201 if (c >= 'A' && c <= 'Z') c |= 0x20; /* lower case */
202 if (c == '.' && i == dlen-3 && de->name[i+1] == ';' && de->name[i+2] == '1')
203 break; /* Drop trailing '.;1' (ISO9660:1988 7.5.1 requires period) */
204 if (c == ';' && i == dlen-2 && de->name[i+1] == '1')
205 break; /* Drop trailing ';1' */
206 if (c == ';') c = '.'; /* Convert remaining ';' to '.' */
207 dpnt[i] = c;
208 }
209 }
210 for(j=0; j<i; j++)
211 put_fs_byte(dpnt[j],j+dirent->d_name); /* And save it */
212 if(dpnt1) {
213 kfree(dpnt);
214 dpnt = dpnt1;
215 }
216
217 dcache_add(inode, dpnt, i, inode_number);
218 };
219 #if 0
220 printk("Nchar: %d\n",i);
221 #endif
222
223 if (rrflag) kfree(dpnt);
224 if (cpnt) {
225 kfree(cpnt);
226 cpnt = NULL;
227 };
228
229 if (i) {
230 put_fs_long(inode_number, &dirent->d_ino);
231 put_fs_byte(0,i+dirent->d_name);
232 put_fs_word(i,&dirent->d_reclen);
233 brelse(bh);
234 return ROUND_UP(NAME_OFFSET(dirent) + i + 1);
235 }
236 }
237 /* We go here for any condition we cannot handle. We also drop through
238 to here at the end of the directory. */
239 out:
240 if (cpnt)
241 kfree(cpnt);
242 brelse(bh);
243 return 0;
244 }
245
246
247
![[last]](../icons/last.png){kind=icon}
![[bottom]](../icons/n_bottom.png){kind=icon}
*/