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/*
* linux/fs/isofs/symlink.c
*
* (C) 1992 Eric Youngdale Modified for ISO9660 filesystem.
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* isofs symlink handling code. This is only used with the Rock Ridge
* extensions to iso9660
*/
#include <asm/segment.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/iso_fs.h>
#include <linux/stat.h>
#include <linux/malloc.h>
static int isofs_readlink(struct inode *, char *, int);
static int isofs_follow_link(struct inode *, struct inode *, int, int, struct inode **);
/*
* symlinks can't do much...
*/
struct inode_operations isofs_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 */
isofs_readlink, /* readlink */
isofs_follow_link, /* follow_link */
NULL, /* bmap */
NULL, /* truncate */
NULL /* permission */
};
static int isofs_follow_link(struct inode * dir, struct inode * inode,
int flag, int mode, struct inode ** res_inode)
{
int error;
char * pnt;
if (!dir) {
dir = current->fs->root;
dir->i_count++;
}
if (!inode) {
iput(dir);
*res_inode = NULL;
return -ENOENT;
}
if (!S_ISLNK(inode->i_mode)) {
iput(dir);
*res_inode = inode;
return 0;
}
if ((current->link_count > 5) ||
!(pnt = get_rock_ridge_symlink(inode))) {
iput(dir);
iput(inode);
*res_inode = NULL;
return -ELOOP;
}
iput(inode);
current->link_count++;
error = open_namei(pnt,flag,mode,res_inode,dir);
current->link_count--;
kfree(pnt);
return error;
}
static int isofs_readlink(struct inode * inode, char * buffer, int buflen)
{
char * pnt;
int i;
char c;
if (!S_ISLNK(inode->i_mode)) {
iput(inode);
return -EINVAL;
}
if (buflen > 1023)
buflen = 1023;
pnt = get_rock_ridge_symlink(inode);
iput(inode);
if (!pnt)
return 0;
i = 0;
while (i<buflen && (c = pnt[i])) {
i++;
put_fs_byte(c,buffer++);
}
kfree(pnt);
return i;
}
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