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/*
* linux/fs/sysv/symlink.c
*
* minix/symlink.c
* Copyright (C) 1991, 1992 Linus Torvalds
*
* coh/symlink.c
* Copyright (C) 1993 Pascal Haible, Bruno Haible
*
* sysv/symlink.c
* Copyright (C) 1993 Bruno Haible
*
* SystemV/Coherent symlink handling code
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/sysv_fs.h>
#include <linux/stat.h>
#include <asm/uaccess.h>
static int sysv_readlink(struct dentry *, char *, int);
static struct dentry *sysv_follow_link(struct dentry *, struct dentry *, unsigned int);
/*
* symlinks can't do much...
*/
struct inode_operations sysv_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 */
sysv_readlink, /* readlink */
sysv_follow_link, /* follow_link */
NULL, /* get_block */
NULL, /* readpage */
NULL, /* writepage */
NULL, /* flushpage */
NULL, /* truncate */
NULL, /* permission */
NULL, /* smap */
NULL /* revalidate */
};
static struct dentry *sysv_follow_link(struct dentry * dentry,
struct dentry * base,
unsigned int follow)
{
struct inode *inode = dentry->d_inode;
struct buffer_head * bh;
bh = sysv_file_bread(inode, 0, 0);
if (!bh) {
dput(base);
return ERR_PTR(-EIO);
}
UPDATE_ATIME(inode);
base = lookup_dentry(bh->b_data, base, follow);
brelse(bh);
return base;
}
static int sysv_readlink(struct dentry * dentry, char * buffer, int buflen)
{
struct inode *inode = dentry->d_inode;
struct buffer_head * bh;
char * bh_data;
int i;
char c;
if (buflen > inode->i_sb->sv_block_size_1)
buflen = inode->i_sb->sv_block_size_1;
bh = sysv_file_bread(inode, 0, 0);
if (!bh)
return 0;
bh_data = bh->b_data;
i = 0;
while (i<buflen && (c = bh_data[i])) {
i++;
put_user(c,buffer++);
}
brelse(bh);
return i;
}
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