1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
/*
* linux/fs/xiafs/symlink.c
*
* Copyright (C) Q. Frank Xia, 1993.
*
* Based on Linus' minix/symlink.c
* Copyright (C) Linus Torvalds, 1991, 1992.
*
* This software may be redistributed per Linux Copyright.
*/
#include <asm/segment.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/xia_fs.h>
#include <linux/stat.h>
static int
xiafs_readlink(struct inode *, char *, int);
static int
xiafs_follow_link(struct inode *, struct inode *, int, int, struct inode **);
/*
* symlinks can't do much...
*/
struct inode_operations xiafs_symlink_inode_operations = {
NULL, /* no file-operations */
NULL, /* create */
NULL, /* lookup */
NULL, /* link */
NULL, /* unlink */
NULL, /* symlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* mknod */
NULL, /* rename */
xiafs_readlink, /* readlink */
xiafs_follow_link, /* follow_link */
NULL, /* bmap */
NULL, /* truncate */
NULL /* permission */
};
static int xiafs_readlink(struct inode * inode, char * buffer, int buflen)
{
struct buffer_head * bh;
int i;
char c;
if (!S_ISLNK(inode->i_mode)) {
iput(inode);
return -EINVAL;
}
if (buflen > BLOCK_SIZE)
buflen = BLOCK_SIZE;
bh = xiafs_bread(inode, 0, 0);
if (!IS_RDONLY (inode)) {
inode->i_atime=CURRENT_TIME;
inode->i_dirt=1;
}
iput(inode);
if (!bh)
return 0;
for (i=0; i < buflen && (c=bh->b_data[i]); i++)
put_fs_byte(c, buffer++);
if (i < buflen-1)
put_fs_byte((char)0, buffer);
brelse(bh);
return i;
}
static int xiafs_follow_link(struct inode * dir, struct inode * inode,
int flag, int mode, struct inode ** res_inode)
{
int error;
struct buffer_head * bh;
*res_inode = NULL;
if (!dir) {
dir = current->root;
dir->i_count++;
}
if (!inode) {
iput(dir);
return -ENOENT;
}
if (!S_ISLNK(inode->i_mode)) {
iput(dir);
*res_inode = inode;
return 0;
}
if (!IS_RDONLY (inode)) {
inode->i_atime=CURRENT_TIME;
inode->i_dirt=1;
}
if (current->link_count > 5) {
iput(inode);
iput(dir);
return -ELOOP;
}
if (!(bh = xiafs_bread(inode, 0, 0))) {
iput(inode);
iput(dir);
return -EIO;
}
iput(inode);
current->link_count++;
error = open_namei(bh->b_data,flag,mode,res_inode,dir);
current->link_count--;
brelse(bh);
return error;
}