diff options
Diffstat (limited to 'fs/squashfs/xattr_id.c')
-rw-r--r-- | fs/squashfs/xattr_id.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/fs/squashfs/xattr_id.c b/fs/squashfs/xattr_id.c new file mode 100644 index 000000000000..cfb41106098f --- /dev/null +++ b/fs/squashfs/xattr_id.c | |||
@@ -0,0 +1,100 @@ | |||
1 | /* | ||
2 | * Squashfs - a compressed read only filesystem for Linux | ||
3 | * | ||
4 | * Copyright (c) 2010 | ||
5 | * Phillip Lougher <phillip@lougher.demon.co.uk> | ||
6 | * | ||
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. | ||
11 | * | ||
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. | ||
16 | * | ||
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. | ||
20 | * | ||
21 | * xattr_id.c | ||
22 | */ | ||
23 | |||
24 | /* | ||
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. | ||
27 | */ | ||
28 | |||
29 | #include <linux/fs.h> | ||
30 | #include <linux/vfs.h> | ||
31 | #include <linux/slab.h> | ||
32 | |||
33 | #include "squashfs_fs.h" | ||
34 | #include "squashfs_fs_sb.h" | ||
35 | #include "squashfs_fs_i.h" | ||
36 | #include "squashfs.h" | ||
37 | |||
38 | /* | ||
39 | * Map xattr id using the xattr id look up table | ||
40 | */ | ||
41 | int squashfs_xattr_lookup(struct super_block *sb, unsigned int index, | ||
42 | int *count, unsigned int *size, unsigned long long *xattr) | ||
43 | { | ||
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; | ||
49 | int err; | ||
50 | |||
51 | err = squashfs_read_metadata(sb, &id, &start_block, &offset, | ||
52 | sizeof(id)); | ||
53 | if (err < 0) | ||
54 | return err; | ||
55 | |||
56 | *xattr = le64_to_cpu(id.xattr); | ||
57 | *size = le32_to_cpu(id.size); | ||
58 | *count = le32_to_cpu(id.count); | ||
59 | return 0; | ||
60 | } | ||
61 | |||
62 | |||
63 | /* | ||
64 | * Read uncompressed xattr id lookup table indexes from disk into memory | ||
65 | */ | ||
66 | __le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 start, | ||
67 | u64 *xattr_table_start, int *xattr_ids) | ||
68 | { | ||
69 | unsigned int len; | ||
70 | __le64 *xid_table; | ||
71 | struct squashfs_xattr_id_table id_table; | ||
72 | int err; | ||
73 | |||
74 | err = squashfs_read_table(sb, &id_table, start, sizeof(id_table)); | ||
75 | if (err < 0) { | ||
76 | ERROR("unable to read xattr id table\n"); | ||
77 | return ERR_PTR(err); | ||
78 | } | ||
79 | *xattr_table_start = le64_to_cpu(id_table.xattr_table_start); | ||
80 | *xattr_ids = le32_to_cpu(id_table.xattr_ids); | ||
81 | len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids); | ||
82 | |||
83 | TRACE("In read_xattr_index_table, length %d\n", len); | ||
84 | |||
85 | /* Allocate xattr id lookup table indexes */ | ||
86 | xid_table = kmalloc(len, GFP_KERNEL); | ||
87 | if (xid_table == NULL) { | ||
88 | ERROR("Failed to allocate xattr id index table\n"); | ||
89 | return ERR_PTR(-ENOMEM); | ||
90 | } | ||
91 | |||
92 | err = squashfs_read_table(sb, xid_table, start + sizeof(id_table), len); | ||
93 | if (err < 0) { | ||
94 | ERROR("unable to read xattr id index table\n"); | ||
95 | kfree(xid_table); | ||
96 | return ERR_PTR(err); | ||
97 | } | ||
98 | |||
99 | return xid_table; | ||
100 | } | ||