d7f2ff6718
My existing email address may stop working in a month or two, so update email to one that will continue working. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
95 lines
2.7 KiB
C
95 lines
2.7 KiB
C
/*
|
|
* Squashfs - a compressed read only filesystem for Linux
|
|
*
|
|
* Copyright (c) 2010
|
|
* Phillip Lougher <phillip@squashfs.org.uk>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2,
|
|
* or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
*
|
|
* xattr_id.c
|
|
*/
|
|
|
|
/*
|
|
* This file implements code to map the 32-bit xattr id stored in the inode
|
|
* into the on disk location of the xattr data.
|
|
*/
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/vfs.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include "squashfs_fs.h"
|
|
#include "squashfs_fs_sb.h"
|
|
#include "squashfs.h"
|
|
#include "xattr.h"
|
|
|
|
/*
|
|
* Map xattr id using the xattr id look up table
|
|
*/
|
|
int squashfs_xattr_lookup(struct super_block *sb, unsigned int index,
|
|
int *count, unsigned int *size, unsigned long long *xattr)
|
|
{
|
|
struct squashfs_sb_info *msblk = sb->s_fs_info;
|
|
int block = SQUASHFS_XATTR_BLOCK(index);
|
|
int offset = SQUASHFS_XATTR_BLOCK_OFFSET(index);
|
|
u64 start_block = le64_to_cpu(msblk->xattr_id_table[block]);
|
|
struct squashfs_xattr_id id;
|
|
int err;
|
|
|
|
err = squashfs_read_metadata(sb, &id, &start_block, &offset,
|
|
sizeof(id));
|
|
if (err < 0)
|
|
return err;
|
|
|
|
*xattr = le64_to_cpu(id.xattr);
|
|
*size = le32_to_cpu(id.size);
|
|
*count = le32_to_cpu(id.count);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* Read uncompressed xattr id lookup table indexes from disk into memory
|
|
*/
|
|
__le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 start,
|
|
u64 *xattr_table_start, int *xattr_ids)
|
|
{
|
|
unsigned int len;
|
|
struct squashfs_xattr_id_table *id_table;
|
|
|
|
id_table = squashfs_read_table(sb, start, sizeof(*id_table));
|
|
if (IS_ERR(id_table))
|
|
return (__le64 *) id_table;
|
|
|
|
*xattr_table_start = le64_to_cpu(id_table->xattr_table_start);
|
|
*xattr_ids = le32_to_cpu(id_table->xattr_ids);
|
|
kfree(id_table);
|
|
|
|
/* Sanity check values */
|
|
|
|
/* there is always at least one xattr id */
|
|
if (*xattr_ids == 0)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
/* xattr_table should be less than start */
|
|
if (*xattr_table_start >= start)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids);
|
|
|
|
TRACE("In read_xattr_index_table, length %d\n", len);
|
|
|
|
return squashfs_read_table(sb, start + sizeof(*id_table), len);
|
|
}
|