126 lines
2.6 KiB
C
126 lines
2.6 KiB
C
/*
|
|
* symlink.c
|
|
*
|
|
* PURPOSE
|
|
* Symlink handling routines for the OSTA-UDF(tm) filesystem.
|
|
*
|
|
* 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) 1998-2001 Ben Fennema
|
|
* (C) 1999 Stelias Computing Inc
|
|
*
|
|
* HISTORY
|
|
*
|
|
* 04/16/99 blf Created.
|
|
*
|
|
*/
|
|
|
|
#include "udfdecl.h"
|
|
#include <linux/uaccess.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/time.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/buffer_head.h>
|
|
#include "udf_i.h"
|
|
|
|
static void udf_pc_to_char(struct super_block *sb, unsigned char *from,
|
|
int fromlen, unsigned char *to)
|
|
{
|
|
struct pathComponent *pc;
|
|
int elen = 0;
|
|
unsigned char *p = to;
|
|
|
|
while (elen < fromlen) {
|
|
pc = (struct pathComponent *)(from + elen);
|
|
switch (pc->componentType) {
|
|
case 1:
|
|
/*
|
|
* Symlink points to some place which should be agreed
|
|
* upon between originator and receiver of the media. Ignore.
|
|
*/
|
|
if (pc->lengthComponentIdent > 0)
|
|
break;
|
|
/* Fall through */
|
|
case 2:
|
|
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:
|
|
p += udf_get_filename(sb, pc->componentIdent, p,
|
|
pc->lengthComponentIdent);
|
|
*p++ = '/';
|
|
break;
|
|
}
|
|
elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
|
|
}
|
|
if (p > to + 1)
|
|
p[-1] = '\0';
|
|
else
|
|
p[0] = '\0';
|
|
}
|
|
|
|
static int udf_symlink_filler(struct file *file, struct page *page)
|
|
{
|
|
struct inode *inode = page->mapping->host;
|
|
struct buffer_head *bh = NULL;
|
|
unsigned char *symlink;
|
|
int err = -EIO;
|
|
unsigned char *p = kmap(page);
|
|
struct udf_inode_info *iinfo;
|
|
uint32_t pos;
|
|
|
|
iinfo = UDF_I(inode);
|
|
pos = udf_block_map(inode, 0);
|
|
|
|
down_read(&iinfo->i_data_sem);
|
|
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
|
|
symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
|
|
} else {
|
|
bh = sb_bread(inode->i_sb, pos);
|
|
|
|
if (!bh)
|
|
goto out;
|
|
|
|
symlink = bh->b_data;
|
|
}
|
|
|
|
udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
|
|
brelse(bh);
|
|
|
|
up_read(&iinfo->i_data_sem);
|
|
SetPageUptodate(page);
|
|
kunmap(page);
|
|
unlock_page(page);
|
|
return 0;
|
|
|
|
out:
|
|
up_read(&iinfo->i_data_sem);
|
|
SetPageError(page);
|
|
kunmap(page);
|
|
unlock_page(page);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* symlinks can't do much...
|
|
*/
|
|
const struct address_space_operations udf_symlink_aops = {
|
|
.readpage = udf_symlink_filler,
|
|
};
|