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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - fs/squashfs/xattr_id.c
2 * Squashfs - a compressed read only filesystem for Linux
5 * Phillip Lougher <phillip@squashfs.org.uk>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2,
10 * or (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
25 * This file implements code to map the 32-bit xattr id stored in the inode
26 * into the on disk location of the xattr data.
30 #include <linux/vfs.h>
31 #include <linux/slab.h>
33 #include "squashfs_fs.h"
34 #include "squashfs_fs_sb.h"
39 * Map xattr id using the xattr id look up table
41 int squashfs_xattr_lookup(struct super_block
*sb
, unsigned int index
,
42 int *count
, unsigned int *size
, unsigned long long *xattr
)
44 struct squashfs_sb_info
*msblk
= sb
->s_fs_info
;
45 int block
= SQUASHFS_XATTR_BLOCK(index
);
46 int offset
= SQUASHFS_XATTR_BLOCK_OFFSET(index
);
47 u64 start_block
= le64_to_cpu(msblk
->xattr_id_table
[block
]);
48 struct squashfs_xattr_id id
;
51 err
= squashfs_read_metadata(sb
, &id
, &start_block
, &offset
,
56 *xattr
= le64_to_cpu(id
.xattr
);
57 *size
= le32_to_cpu(id
.size
);
58 *count
= le32_to_cpu(id
.count
);
64 * Read uncompressed xattr id lookup table indexes from disk into memory
66 __le64
*squashfs_read_xattr_id_table(struct super_block
*sb
, u64 start
,
67 u64
*xattr_table_start
, int *xattr_ids
)
70 struct squashfs_xattr_id_table
*id_table
;
72 id_table
= squashfs_read_table(sb
, start
, sizeof(*id_table
));
74 return (__le64
*) id_table
;
76 *xattr_table_start
= le64_to_cpu(id_table
->xattr_table_start
);
77 *xattr_ids
= le32_to_cpu(id_table
->xattr_ids
);
80 /* Sanity check values */
82 /* there is always at least one xattr id */
84 return ERR_PTR(-EINVAL
);
86 /* xattr_table should be less than start */
87 if (*xattr_table_start
>= start
)
88 return ERR_PTR(-EINVAL
);
90 len
= SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids
);
92 TRACE("In read_xattr_index_table, length %d\n", len
);
94 return squashfs_read_table(sb
, start
+ sizeof(*id_table
), len
);