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/*
* linux/fs/ext2/symlink.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/symlink.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* ext2 symlink handling code
*/
#include <asm/uaccess.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/stat.h>
static int ext2_readlink (struct dentry *, char *, int);
static struct dentry *ext2_follow_link(struct dentry *, struct dentry *, unsigned int);
/*
* symlinks can't do much...
*/
struct inode_operations ext2_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 */
ext2_readlink, /* readlink */
ext2_follow_link, /* follow_link */
NULL, /* readpage */
NULL, /* writepage */
NULL, /* bmap */
NULL, /* truncate */
NULL, /* permission */
NULL /* smap */
};
static struct dentry * ext2_follow_link(struct dentry * dentry,
struct dentry *base,
unsigned int follow)
{
struct inode *inode = dentry->d_inode;
struct buffer_head * bh = NULL;
int error;
char * link;
link = (char *) inode->u.ext2_i.i_data;
if (inode->i_blocks) {
if (!(bh = ext2_bread (inode, 0, 0, &error))) {
dput(base);
return ERR_PTR(-EIO);
}
link = bh->b_data;
}
UPDATE_ATIME(inode);
base = lookup_dentry(link, base, follow);
if (bh)
brelse(bh);
return base;
}
static int ext2_readlink (struct dentry * dentry, char * buffer, int buflen)
{
struct inode *inode = dentry->d_inode;
struct buffer_head * bh = NULL;
char * link;
int i;
if (buflen > inode->i_sb->s_blocksize - 1)
buflen = inode->i_sb->s_blocksize - 1;
link = (char *) inode->u.ext2_i.i_data;
if (inode->i_blocks) {
int err;
bh = ext2_bread (inode, 0, 0, &err);
if (!bh) {
if(err < 0) /* indicate type of error */
return err;
return 0;
}
link = bh->b_data;
}
i = 0;
while (i < buflen && link[i])
i++;
if (copy_to_user(buffer, link, i))
i = -EFAULT;
UPDATE_ATIME(inode);
if (bh)
brelse (bh);
return i;
}
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