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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
34/*
35 * This file (and decompressor.h) implements a decompressor framework for
36 * Squashfs, allowing multiple decompressors to be easily supported
37 */
38
39static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
40 NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
41};
42
43#ifndef CONFIG_SQUASHFS_LZO
44static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
45 NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
46};
47#endif
48
49#ifndef CONFIG_SQUASHFS_XZ
50static const struct squashfs_decompressor squashfs_xz_comp_ops = {
51 NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0
52};
53#endif
54
55#ifndef CONFIG_SQUASHFS_ZLIB
56static const struct squashfs_decompressor squashfs_zlib_comp_ops = {
57 NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0
58};
59#endif
60
61static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
62 NULL, NULL, NULL, 0, "unknown", 0
63};
64
65static const struct squashfs_decompressor *decompressor[] = {
66 &squashfs_zlib_comp_ops,
67 &squashfs_lzo_comp_ops,
68 &squashfs_xz_comp_ops,
69 &squashfs_lzma_unsupported_comp_ops,
70 &squashfs_unknown_comp_ops
71};
72
73
74const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
75{
76 int i;
77
78 for (i = 0; decompressor[i]->id; i++)
79 if (id == decompressor[i]->id)
80 break;
81
82 return decompressor[i];
83}
84
85
86void *squashfs_decompressor_init(struct super_block *sb, unsigned short flags)
87{
88 struct squashfs_sb_info *msblk = sb->s_fs_info;
89 void *strm, *buffer = NULL;
90 int length = 0;
91
92 /*
93 * Read decompressor specific options from file system if present
94 */
95 if (SQUASHFS_COMP_OPTS(flags)) {
96 buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
97 if (buffer == NULL)
98 return ERR_PTR(-ENOMEM);
99
100 length = squashfs_read_data(sb, &buffer,
101 sizeof(struct squashfs_super_block), 0, NULL,
102 PAGE_CACHE_SIZE, 1);
103
104 if (length < 0) {
105 strm = ERR_PTR(length);
106 goto finished;
107 }
108 }
109
110 strm = msblk->decompressor->init(msblk, buffer, length);
111
112finished:
113 kfree(buffer);
114
115 return strm;
116}