1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Squashfs - a compressed read only filesystem for Linux
*
* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
* Phillip Lougher <phillip@squashfs.org.uk>
*
* decompressor.c
*/
#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/buffer_head.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "decompressor.h"
#include "squashfs.h"
#include "page_actor.h"
/*
* This file (and decompressor.h) implements a decompressor framework for
* Squashfs, allowing multiple decompressors to be easily supported
*/
static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
};
#ifndef CONFIG_SQUASHFS_LZ4
static const struct squashfs_decompressor squashfs_lz4_comp_ops = {
NULL, NULL, NULL, NULL, LZ4_COMPRESSION, "lz4", 0
};
#endif
#ifndef CONFIG_SQUASHFS_LZO
static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
};
#endif
#ifndef CONFIG_SQUASHFS_XZ
static const struct squashfs_decompressor squashfs_xz_comp_ops = {
NULL, NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0
};
#endif
#ifndef CONFIG_SQUASHFS_ZLIB
static const struct squashfs_decompressor squashfs_zlib_comp_ops = {
NULL, NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0
};
#endif
#ifndef CONFIG_SQUASHFS_ZSTD
static const struct squashfs_decompressor squashfs_zstd_comp_ops = {
NULL, NULL, NULL, NULL, ZSTD_COMPRESSION, "zstd", 0
};
#endif
static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
NULL, NULL, NULL, NULL, 0, "unknown", 0
};
static const struct squashfs_decompressor *decompressor[] = {
&squashfs_zlib_comp_ops,
&squashfs_lz4_comp_ops,
&squashfs_lzo_comp_ops,
&squashfs_xz_comp_ops,
&squashfs_lzma_unsupported_comp_ops,
&squashfs_zstd_comp_ops,
&squashfs_unknown_comp_ops
};
const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
{
int i;
for (i = 0; decompressor[i]->id; i++)
if (id == decompressor[i]->id)
break;
return decompressor[i];
}
static void *get_comp_opts(struct super_block *sb, unsigned short flags)
{
struct squashfs_sb_info *msblk = sb->s_fs_info;
void *buffer = NULL, *comp_opts;
struct squashfs_page_actor *actor = NULL;
int length = 0;
/*
* Read decompressor specific options from file system if present
*/
if (SQUASHFS_COMP_OPTS(flags)) {
buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (buffer == NULL) {
comp_opts = ERR_PTR(-ENOMEM);
goto out;
}
actor = squashfs_page_actor_init(&buffer, 1, 0);
if (actor == NULL) {
comp_opts = ERR_PTR(-ENOMEM);
goto out;
}
length = squashfs_read_data(sb,
sizeof(struct squashfs_super_block), 0, NULL, actor);
if (length < 0) {
comp_opts = ERR_PTR(length);
goto out;
}
}
comp_opts = squashfs_comp_opts(msblk, buffer, length);
out:
kfree(actor);
kfree(buffer);
return comp_opts;
}
void *squashfs_decompressor_setup(struct super_block *sb, unsigned short flags)
{
struct squashfs_sb_info *msblk = sb->s_fs_info;
void *stream, *comp_opts = get_comp_opts(sb, flags);
if (IS_ERR(comp_opts))
return comp_opts;
stream = msblk->thread_ops->create(msblk, comp_opts);
if (IS_ERR(stream))
kfree(comp_opts);
return stream;
}
|
