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1/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
5 * Phillip Lougher <phillip@squashfs.org.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 * decompressor.c
22 */
23
24#include <linux/types.h>
25#include <linux/mutex.h>
26#include <linux/slab.h>
27#include <linux/buffer_head.h>
28
29#include "squashfs_fs.h"
30#include "squashfs_fs_sb.h"
31#include "decompressor.h"
32#include "squashfs.h"
33#include "page_actor.h"
34
35/*
36 * This file (and decompressor.h) implements a decompressor framework for
37 * Squashfs, allowing multiple decompressors to be easily supported
38 */
39
40static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
41 NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
42};
43
44#ifndef CONFIG_SQUASHFS_LZ4
45static const struct squashfs_decompressor squashfs_lz4_comp_ops = {
46 NULL, NULL, NULL, NULL, LZ4_COMPRESSION, "lz4", 0
47};
48#endif
49
50#ifndef CONFIG_SQUASHFS_LZO
51static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
52 NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
53};
54#endif
55
56#ifndef CONFIG_SQUASHFS_XZ
57static const struct squashfs_decompressor squashfs_xz_comp_ops = {
58 NULL, NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0
59};
60#endif
61
62#ifndef CONFIG_SQUASHFS_ZLIB
63static const struct squashfs_decompressor squashfs_zlib_comp_ops = {
64 NULL, NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0
65};
66#endif
67
68static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
69 NULL, NULL, NULL, NULL, 0, "unknown", 0
70};
71
72static const struct squashfs_decompressor *decompressor[] = {
73 &squashfs_zlib_comp_ops,
74 &squashfs_lz4_comp_ops,
75 &squashfs_lzo_comp_ops,
76 &squashfs_xz_comp_ops,
77 &squashfs_lzma_unsupported_comp_ops,
78 &squashfs_unknown_comp_ops
79};
80
81
82const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
83{
84 int i;
85
86 for (i = 0; decompressor[i]->id; i++)
87 if (id == decompressor[i]->id)
88 break;
89
90 return decompressor[i];
91}
92
93
94static void *get_comp_opts(struct super_block *sb, unsigned short flags)
95{
96 struct squashfs_sb_info *msblk = sb->s_fs_info;
97 void *buffer = NULL, *comp_opts;
98 struct squashfs_page_actor *actor = NULL;
99 int length = 0;
100
101 /*
102 * Read decompressor specific options from file system if present
103 */
104 if (SQUASHFS_COMP_OPTS(flags)) {
105 buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
106 if (buffer == NULL) {
107 comp_opts = ERR_PTR(-ENOMEM);
108 goto out;
109 }
110
111 actor = squashfs_page_actor_init(&buffer, 1, 0);
112 if (actor == NULL) {
113 comp_opts = ERR_PTR(-ENOMEM);
114 goto out;
115 }
116
117 length = squashfs_read_data(sb,
118 sizeof(struct squashfs_super_block), 0, NULL, actor);
119
120 if (length < 0) {
121 comp_opts = ERR_PTR(length);
122 goto out;
123 }
124 }
125
126 comp_opts = squashfs_comp_opts(msblk, buffer, length);
127
128out:
129 kfree(actor);
130 kfree(buffer);
131 return comp_opts;
132}
133
134
135void *squashfs_decompressor_setup(struct super_block *sb, unsigned short flags)
136{
137 struct squashfs_sb_info *msblk = sb->s_fs_info;
138 void *stream, *comp_opts = get_comp_opts(sb, flags);
139
140 if (IS_ERR(comp_opts))
141 return comp_opts;
142
143 stream = squashfs_decompressor_create(msblk, comp_opts);
144 if (IS_ERR(stream))
145 kfree(comp_opts);
146
147 return stream;
148}
1/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
5 * Phillip Lougher <phillip@squashfs.org.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 * decompressor.c
22 */
23
24#include <linux/types.h>
25#include <linux/mutex.h>
26#include <linux/slab.h>
27#include <linux/buffer_head.h>
28
29#include "squashfs_fs.h"
30#include "squashfs_fs_sb.h"
31#include "decompressor.h"
32#include "squashfs.h"
33#include "page_actor.h"
34
35/*
36 * This file (and decompressor.h) implements a decompressor framework for
37 * Squashfs, allowing multiple decompressors to be easily supported
38 */
39
40static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
41 NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
42};
43
44#ifndef CONFIG_SQUASHFS_LZ4
45static const struct squashfs_decompressor squashfs_lz4_comp_ops = {
46 NULL, NULL, NULL, NULL, LZ4_COMPRESSION, "lz4", 0
47};
48#endif
49
50#ifndef CONFIG_SQUASHFS_LZO
51static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
52 NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
53};
54#endif
55
56#ifndef CONFIG_SQUASHFS_XZ
57static const struct squashfs_decompressor squashfs_xz_comp_ops = {
58 NULL, NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0
59};
60#endif
61
62#ifndef CONFIG_SQUASHFS_ZLIB
63static const struct squashfs_decompressor squashfs_zlib_comp_ops = {
64 NULL, NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0
65};
66#endif
67
68#ifndef CONFIG_SQUASHFS_ZSTD
69static const struct squashfs_decompressor squashfs_zstd_comp_ops = {
70 NULL, NULL, NULL, NULL, ZSTD_COMPRESSION, "zstd", 0
71};
72#endif
73
74static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
75 NULL, NULL, NULL, NULL, 0, "unknown", 0
76};
77
78static const struct squashfs_decompressor *decompressor[] = {
79 &squashfs_zlib_comp_ops,
80 &squashfs_lz4_comp_ops,
81 &squashfs_lzo_comp_ops,
82 &squashfs_xz_comp_ops,
83 &squashfs_lzma_unsupported_comp_ops,
84 &squashfs_zstd_comp_ops,
85 &squashfs_unknown_comp_ops
86};
87
88
89const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
90{
91 int i;
92
93 for (i = 0; decompressor[i]->id; i++)
94 if (id == decompressor[i]->id)
95 break;
96
97 return decompressor[i];
98}
99
100
101static void *get_comp_opts(struct super_block *sb, unsigned short flags)
102{
103 struct squashfs_sb_info *msblk = sb->s_fs_info;
104 void *buffer = NULL, *comp_opts;
105 struct squashfs_page_actor *actor = NULL;
106 int length = 0;
107
108 /*
109 * Read decompressor specific options from file system if present
110 */
111 if (SQUASHFS_COMP_OPTS(flags)) {
112 buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
113 if (buffer == NULL) {
114 comp_opts = ERR_PTR(-ENOMEM);
115 goto out;
116 }
117
118 actor = squashfs_page_actor_init(&buffer, 1, 0);
119 if (actor == NULL) {
120 comp_opts = ERR_PTR(-ENOMEM);
121 goto out;
122 }
123
124 length = squashfs_read_data(sb,
125 sizeof(struct squashfs_super_block), 0, NULL, actor);
126
127 if (length < 0) {
128 comp_opts = ERR_PTR(length);
129 goto out;
130 }
131 }
132
133 comp_opts = squashfs_comp_opts(msblk, buffer, length);
134
135out:
136 kfree(actor);
137 kfree(buffer);
138 return comp_opts;
139}
140
141
142void *squashfs_decompressor_setup(struct super_block *sb, unsigned short flags)
143{
144 struct squashfs_sb_info *msblk = sb->s_fs_info;
145 void *stream, *comp_opts = get_comp_opts(sb, flags);
146
147 if (IS_ERR(comp_opts))
148 return comp_opts;
149
150 stream = squashfs_decompressor_create(msblk, comp_opts);
151 if (IS_ERR(stream))
152 kfree(comp_opts);
153
154 return stream;
155}