Commit | Line | Data |
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68252eb5 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
4b5397dc PL |
2 | /* |
3 | * Squashfs - a compressed read only filesystem for Linux | |
4 | * | |
5 | * Copyright (c) 2010 | |
d7f2ff67 | 6 | * Phillip Lougher <phillip@squashfs.org.uk> |
4b5397dc | 7 | * |
4b5397dc PL |
8 | * xattr_id.c |
9 | */ | |
10 | ||
11 | /* | |
12 | * This file implements code to map the 32-bit xattr id stored in the inode | |
13 | * into the on disk location of the xattr data. | |
14 | */ | |
15 | ||
16 | #include <linux/fs.h> | |
17 | #include <linux/vfs.h> | |
18 | #include <linux/slab.h> | |
19 | ||
20 | #include "squashfs_fs.h" | |
21 | #include "squashfs_fs_sb.h" | |
4b5397dc | 22 | #include "squashfs.h" |
5f3b321d | 23 | #include "xattr.h" |
4b5397dc PL |
24 | |
25 | /* | |
26 | * Map xattr id using the xattr id look up table | |
27 | */ | |
28 | int squashfs_xattr_lookup(struct super_block *sb, unsigned int index, | |
aa5b1894 | 29 | int *count, unsigned int *size, unsigned long long *xattr) |
4b5397dc PL |
30 | { |
31 | struct squashfs_sb_info *msblk = sb->s_fs_info; | |
32 | int block = SQUASHFS_XATTR_BLOCK(index); | |
33 | int offset = SQUASHFS_XATTR_BLOCK_OFFSET(index); | |
34 | u64 start_block = le64_to_cpu(msblk->xattr_id_table[block]); | |
35 | struct squashfs_xattr_id id; | |
36 | int err; | |
37 | ||
38 | err = squashfs_read_metadata(sb, &id, &start_block, &offset, | |
39 | sizeof(id)); | |
40 | if (err < 0) | |
41 | return err; | |
42 | ||
43 | *xattr = le64_to_cpu(id.xattr); | |
44 | *size = le32_to_cpu(id.size); | |
45 | *count = le32_to_cpu(id.count); | |
46 | return 0; | |
47 | } | |
48 | ||
49 | ||
50 | /* | |
51 | * Read uncompressed xattr id lookup table indexes from disk into memory | |
52 | */ | |
53 | __le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 start, | |
54 | u64 *xattr_table_start, int *xattr_ids) | |
55 | { | |
56 | unsigned int len; | |
82de647e PL |
57 | struct squashfs_xattr_id_table *id_table; |
58 | ||
59 | id_table = squashfs_read_table(sb, start, sizeof(*id_table)); | |
60 | if (IS_ERR(id_table)) | |
61 | return (__le64 *) id_table; | |
4b5397dc | 62 | |
82de647e PL |
63 | *xattr_table_start = le64_to_cpu(id_table->xattr_table_start); |
64 | *xattr_ids = le32_to_cpu(id_table->xattr_ids); | |
65 | kfree(id_table); | |
6f048645 PL |
66 | |
67 | /* Sanity check values */ | |
68 | ||
69 | /* there is always at least one xattr id */ | |
70 | if (*xattr_ids == 0) | |
71 | return ERR_PTR(-EINVAL); | |
72 | ||
73 | /* xattr_table should be less than start */ | |
74 | if (*xattr_table_start >= start) | |
75 | return ERR_PTR(-EINVAL); | |
76 | ||
4b5397dc PL |
77 | len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids); |
78 | ||
79 | TRACE("In read_xattr_index_table, length %d\n", len); | |
80 | ||
82de647e | 81 | return squashfs_read_table(sb, start + sizeof(*id_table), len); |
4b5397dc | 82 | } |