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/*
* linux/fs/ufs/ufs_symlink.c
*
* Copyright (C) 1996
* Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
* Laboratory for Computer Science Research Computing Facility
* Rutgers, The State University of New Jersey
*
* Ported to 2.1.62 by Francois-Rene Rideau <rideau@ens.fr> 19971109
*
* 4.4BSD (FreeBSD) support added on February 1st 1998 by
* Niels Kristian Bech Jensen <nkbj@image.dk> partially based
* on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>.
*/
#include <linux/fs.h>
#include <linux/ufs_fs.h>
#include <linux/sched.h>
#include <asm/uaccess.h>
extern int ufs_bmap (struct inode *, int);
static int
ufs_readlink(struct dentry * dentry, char * buffer, int buflen)
{
struct inode * inode = dentry->d_inode;
struct super_block * sb = inode->i_sb;
unsigned long int block;
struct buffer_head * bh = NULL;
char * link;
int i;
char c;
if (sb->u.ufs_sb.s_flags & (UFS_DEBUG|UFS_DEBUG_LINKS)) {
printk("ufs_readlink: called on ino %lu dev %u/%u\n",
inode->i_ino, MAJOR(inode->i_dev), MINOR(inode->i_dev));
}
if (!S_ISLNK(inode->i_mode)) {
return -EINVAL;
}
if (buflen > sb->s_blocksize - 1)
buflen = sb->s_blocksize - 1;
if (inode->i_blocks) {
/* XXX - error checking */
block = ufs_bmap(inode, 0);
if (sb->u.ufs_sb.s_flags &(UFS_DEBUG|UFS_DEBUG_LINKS)) {
printk("ufs_readlink: bmap got %lu for ino %lu\n",
block, inode->i_ino);
}
bh = bread(inode->i_dev, block, sb->s_blocksize);
if (!bh) {
printk("ufs_readlink: can't read block 0 for ino %lu on dev %u/%u\n",
inode->i_ino, MAJOR(inode->i_dev),
MINOR(inode->i_dev));
return 0;
}
link = bh->b_data;
/* no need to bswap */
} else /* fast symlink */ {
link = (char *)&(inode->u.ufs_i.i_u1.i_symlink[0]);
}
i = 0;
while (i < buflen && (c = link[i])) {
i++;
put_user (c, buffer++);
}
brelse (bh);
return i;
}
/*
* XXX - blatantly stolen from minix fs
*/
static struct dentry *
ufs_follow_link(struct dentry * dentry, struct dentry * base)
{
struct inode * inode = dentry->d_inode;
unsigned long int block;
struct buffer_head * bh = NULL;
char * link;
if (inode->i_sb->u.ufs_sb.s_flags & (UFS_DEBUG|UFS_DEBUG_LINKS)) {
printk("ufs_follow_link: called on ino %lu dev %u/%u\n",
inode->i_ino, MAJOR(inode->i_dev), MINOR(inode->i_dev));
}
if (inode->i_blocks) {
/* read the link from disk */
/* XXX - error checking */
block = ufs_bmap(inode, 0);
bh = bread(inode->i_dev, block, inode->i_sb->s_blocksize);
if (bh == NULL) {
printk("ufs_follow_link: can't read block 0 for ino %lu on dev %u/%u\n",
inode->i_ino, MAJOR(inode->i_dev),
MINOR(inode->i_dev));
dput(base);
return ERR_PTR(-EIO);
}
link = bh->b_data;
} else /* fast symlink */ {
link = (char *)&(inode->u.ufs_i.i_u1.i_symlink[0]);
}
base = lookup_dentry(link, base, 1);
brelse (bh);
return base;
}
static struct file_operations ufs_symlink_operations = {
NULL, /* lseek */
NULL, /* read */
NULL, /* write */
NULL, /* readdir */
NULL, /* select */
NULL, /* ioctl */
NULL, /* mmap */
NULL, /* open */
NULL, /* release */
NULL, /* fsync */ /* XXX - is this ok? */
NULL, /* fasync */
NULL, /* check_media_change */
NULL, /* revalidate */
};
struct inode_operations ufs_symlink_inode_operations = {
&ufs_symlink_operations, /* default directory file operations */
NULL, /* create */
NULL, /* lookup */
NULL, /* link */
NULL, /* unlink */
NULL, /* symlink */
NULL, /* mkdir */
NULL, /* rmdir */
NULL, /* mknod */
NULL, /* rename */
&ufs_readlink, /* readlink */
&ufs_follow_link, /* follow_link */
NULL, /* readpage */
NULL, /* writepage */
NULL, /* bmap */
NULL, /* truncate */
NULL, /* permission */
};
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