]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blame - fs/squashfs/decompressor.c
Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
[mirror_ubuntu-bionic-kernel.git] / fs / squashfs / decompressor.c
CommitLineData
4c0f0bb2
PL
1/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
d7f2ff67 5 * Phillip Lougher <phillip@squashfs.org.uk>
4c0f0bb2
PL
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>
b7fc0ff0 26#include <linux/slab.h>
4c0f0bb2
PL
27#include <linux/buffer_head.h>
28
29#include "squashfs_fs.h"
30#include "squashfs_fs_sb.h"
4c0f0bb2
PL
31#include "decompressor.h"
32#include "squashfs.h"
846b730e 33#include "page_actor.h"
4c0f0bb2
PL
34
35/*
36 * This file (and decompressor.h) implements a decompressor framework for
37 * Squashfs, allowing multiple decompressors to be easily supported
38 */
39
dc325678 40static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
9508c6b9 41 NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0
dc325678
PL
42};
43
62421645
PL
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
79cb8ced 50#ifndef CONFIG_SQUASHFS_LZO
01a678c5 51static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
9508c6b9 52 NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
dc325678 53};
79cb8ced 54#endif
dc325678 55
7a43ae52
PL
56#ifndef CONFIG_SQUASHFS_XZ
57static const struct squashfs_decompressor squashfs_xz_comp_ops = {
9508c6b9 58 NULL, NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0
7a43ae52
PL
59};
60#endif
61
cc6d3497
PL
62#ifndef CONFIG_SQUASHFS_ZLIB
63static const struct squashfs_decompressor squashfs_zlib_comp_ops = {
9508c6b9 64 NULL, NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0
cc6d3497
PL
65};
66#endif
67
4c0f0bb2 68static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
9508c6b9 69 NULL, NULL, NULL, NULL, 0, "unknown", 0
4c0f0bb2
PL
70};
71
72static const struct squashfs_decompressor *decompressor[] = {
73 &squashfs_zlib_comp_ops,
62421645 74 &squashfs_lz4_comp_ops,
79cb8ced 75 &squashfs_lzo_comp_ops,
7a43ae52 76 &squashfs_xz_comp_ops,
01a678c5 77 &squashfs_lzma_unsupported_comp_ops,
4c0f0bb2
PL
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}
b7fc0ff0
PL
92
93
9508c6b9 94static void *get_comp_opts(struct super_block *sb, unsigned short flags)
b7fc0ff0
PL
95{
96 struct squashfs_sb_info *msblk = sb->s_fs_info;
9508c6b9 97 void *buffer = NULL, *comp_opts;
846b730e 98 struct squashfs_page_actor *actor = NULL;
b7fc0ff0
PL
99 int length = 0;
100
101 /*
102 * Read decompressor specific options from file system if present
103 */
104 if (SQUASHFS_COMP_OPTS(flags)) {
09cbfeaf 105 buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
9508c6b9
PL
106 if (buffer == NULL) {
107 comp_opts = ERR_PTR(-ENOMEM);
108 goto out;
109 }
b7fc0ff0 110
846b730e
PL
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);
b7fc0ff0
PL
119
120 if (length < 0) {
9508c6b9
PL
121 comp_opts = ERR_PTR(length);
122 goto out;
b7fc0ff0
PL
123 }
124 }
125
9508c6b9 126 comp_opts = squashfs_comp_opts(msblk, buffer, length);
b7fc0ff0 127
9508c6b9 128out:
846b730e 129 kfree(actor);
b7fc0ff0 130 kfree(buffer);
9508c6b9
PL
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);
b7fc0ff0 146
9508c6b9 147 return stream;
b7fc0ff0 148}