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/*
* symlink.c
*
* PURPOSE
* Symlink handling routines for the OSTA-UDF(tm) filesystem.
*
* CONTACTS
* E-mail regarding any portion of the Linux UDF file system should be
* directed to the development team mailing list (run by majordomo):
* linux_udf@hootie.lvld.hp.com
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1998-2000 Ben Fennema
* (C) 1999 Stelias Computing Inc
*
* HISTORY
*
* 04/16/99 blf Created.
*
*/
#include "udfdecl.h"
#include <asm/uaccess.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/udf_fs.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/stat.h>
#include <linux/malloc.h>
#include <linux/pagemap.h>
#include "udf_i.h"
static void udf_pc_to_char(char *from, int fromlen, char *to)
{
struct PathComponent *pc;
int elen = 0;
char *p = to;
while (elen < fromlen)
{
pc = (struct PathComponent *)(from + elen);
switch (pc->componentType)
{
case 1:
if (pc->lengthComponentIdent == 0)
{
p = to;
*p++ = '/';
}
break;
case 3:
memcpy(p, "../", 3);
p += 3;
break;
case 4:
memcpy(p, "./", 2);
p += 2;
/* that would be . - just ignore */
break;
case 5:
memcpy(p, pc->componentIdent, pc->lengthComponentIdent);
p += pc->lengthComponentIdent;
*p++ = '/';
}
elen += sizeof(struct PathComponent) + pc->lengthComponentIdent;
}
if (p > to+1)
p[-1] = '\0';
else
p[0] = '\0';
}
static int udf_symlink_filler(struct dentry * dentry, struct page *page)
{
struct inode *inode = dentry->d_inode;
struct buffer_head *bh = NULL;
char *symlink;
int err = -EIO;
char *p = (char *)kmap(page);
if (UDF_I_ALLOCTYPE(inode) == ICB_FLAG_AD_IN_ICB)
{
bh = udf_tread(inode->i_sb, inode->i_ino, inode->i_sb->s_blocksize);
if (!bh)
goto out;
symlink = bh->b_data + udf_file_entry_alloc_offset(inode);
}
else
{
bh = bread(inode->i_dev, udf_block_map(inode, 0),
inode->i_sb->s_blocksize);
if (!bh)
goto out;
symlink = bh->b_data;
}
udf_pc_to_char(symlink, inode->i_size, p);
udf_release_data(bh);
SetPageUptodate(page);
kunmap(page);
UnlockPage(page);
return 0;
out:
SetPageError(page);
kunmap(page);
UnlockPage(page);
return err;
}
/*
* symlinks can't do much...
*/
struct inode_operations udf_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 */
page_readlink, /* readlink */
page_follow_link, /* follow_link */
NULL, /* get_block */
udf_symlink_filler, /* readpage */
NULL, /* writepage */
NULL, /* truncate */
NULL, /* permission */
NULL /* revalidate */
};
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