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Phillip Lougher4c0f0bb2009-10-06 04:04:15 +01001/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Phillip Lougherd7f2ff62011-05-26 10:39:56 +01005 * Phillip Lougher <phillip@squashfs.org.uk>
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +01006 *
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>
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +000026#include <linux/slab.h>
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010027#include <linux/buffer_head.h>
28
29#include "squashfs_fs.h"
30#include "squashfs_fs_sb.h"
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010031#include "decompressor.h"
32#include "squashfs.h"
Phillip Lougher846b7302013-11-18 02:59:12 +000033#include "page_actor.h"
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010034
35/*
36 * This file (and decompressor.h) implements a decompressor framework for
37 * Squashfs, allowing multiple decompressors to be easily supported
38 */
39
Phillip Lougherdc325672009-10-14 03:58:11 +010040static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
Phillip Lougher9508c6b2013-11-13 02:56:26 +000041 NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
Phillip Lougherdc325672009-10-14 03:58:11 +010042};
43
Phillip Lougher62421642014-11-27 18:48:44 +000044#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
Chan Jeong79cb8ce2010-08-05 02:29:59 +010050#ifndef CONFIG_SQUASHFS_LZO
Phillip Lougher01a678c2011-01-05 18:23:53 +000051static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
Phillip Lougher9508c6b2013-11-13 02:56:26 +000052 NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
Phillip Lougherdc325672009-10-14 03:58:11 +010053};
Chan Jeong79cb8ce2010-08-05 02:29:59 +010054#endif
Phillip Lougherdc325672009-10-14 03:58:11 +010055
Phillip Lougher7a43ae52010-12-09 02:08:31 +000056#ifndef CONFIG_SQUASHFS_XZ
57static const struct squashfs_decompressor squashfs_xz_comp_ops = {
Phillip Lougher9508c6b2013-11-13 02:56:26 +000058 NULL, NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0
Phillip Lougher7a43ae52010-12-09 02:08:31 +000059};
60#endif
61
Phillip Loughercc6d3492011-07-22 03:01:28 +010062#ifndef CONFIG_SQUASHFS_ZLIB
63static const struct squashfs_decompressor squashfs_zlib_comp_ops = {
Phillip Lougher9508c6b2013-11-13 02:56:26 +000064 NULL, NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0
Phillip Loughercc6d3492011-07-22 03:01:28 +010065};
66#endif
67
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010068static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
Phillip Lougher9508c6b2013-11-13 02:56:26 +000069 NULL, NULL, NULL, NULL, 0, "unknown", 0
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010070};
71
72static const struct squashfs_decompressor *decompressor[] = {
73 &squashfs_zlib_comp_ops,
Phillip Lougher62421642014-11-27 18:48:44 +000074 &squashfs_lz4_comp_ops,
Chan Jeong79cb8ce2010-08-05 02:29:59 +010075 &squashfs_lzo_comp_ops,
Phillip Lougher7a43ae52010-12-09 02:08:31 +000076 &squashfs_xz_comp_ops,
Phillip Lougher01a678c2011-01-05 18:23:53 +000077 &squashfs_lzma_unsupported_comp_ops,
Phillip Lougher4c0f0bb2009-10-06 04:04:15 +010078 &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}
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +000092
93
Phillip Lougher9508c6b2013-11-13 02:56:26 +000094static void *get_comp_opts(struct super_block *sb, unsigned short flags)
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +000095{
96 struct squashfs_sb_info *msblk = sb->s_fs_info;
Phillip Lougher9508c6b2013-11-13 02:56:26 +000097 void *buffer = NULL, *comp_opts;
Phillip Lougher846b7302013-11-18 02:59:12 +000098 struct squashfs_page_actor *actor = NULL;
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +000099 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_CACHE_SIZE, GFP_KERNEL);
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000106 if (buffer == NULL) {
107 comp_opts = ERR_PTR(-ENOMEM);
108 goto out;
109 }
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +0000110
Phillip Lougher846b7302013-11-18 02:59:12 +0000111 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);
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +0000119
120 if (length < 0) {
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000121 comp_opts = ERR_PTR(length);
122 goto out;
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +0000123 }
124 }
125
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000126 comp_opts = squashfs_comp_opts(msblk, buffer, length);
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +0000127
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000128out:
Phillip Lougher846b7302013-11-18 02:59:12 +0000129 kfree(actor);
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +0000130 kfree(buffer);
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000131 return comp_opts;
132}
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +0000133
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000134
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;
Phillip Lougherb7fc0ff2011-02-28 01:45:42 +0000148}