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Commit | Line | Data |
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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 | 40 | static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = { |
9508c6b9 | 41 | NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0 |
dc325678 PL |
42 | }; |
43 | ||
79cb8ced | 44 | #ifndef CONFIG_SQUASHFS_LZO |
01a678c5 | 45 | static const struct squashfs_decompressor squashfs_lzo_comp_ops = { |
9508c6b9 | 46 | NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0 |
dc325678 | 47 | }; |
79cb8ced | 48 | #endif |
dc325678 | 49 | |
7a43ae52 PL |
50 | #ifndef CONFIG_SQUASHFS_XZ |
51 | static const struct squashfs_decompressor squashfs_xz_comp_ops = { | |
9508c6b9 | 52 | NULL, NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0 |
7a43ae52 PL |
53 | }; |
54 | #endif | |
55 | ||
cc6d3497 PL |
56 | #ifndef CONFIG_SQUASHFS_ZLIB |
57 | static const struct squashfs_decompressor squashfs_zlib_comp_ops = { | |
9508c6b9 | 58 | NULL, NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0 |
cc6d3497 PL |
59 | }; |
60 | #endif | |
61 | ||
4c0f0bb2 | 62 | static const struct squashfs_decompressor squashfs_unknown_comp_ops = { |
9508c6b9 | 63 | NULL, NULL, NULL, NULL, 0, "unknown", 0 |
4c0f0bb2 PL |
64 | }; |
65 | ||
66 | static const struct squashfs_decompressor *decompressor[] = { | |
67 | &squashfs_zlib_comp_ops, | |
79cb8ced | 68 | &squashfs_lzo_comp_ops, |
7a43ae52 | 69 | &squashfs_xz_comp_ops, |
01a678c5 | 70 | &squashfs_lzma_unsupported_comp_ops, |
4c0f0bb2 PL |
71 | &squashfs_unknown_comp_ops |
72 | }; | |
73 | ||
74 | ||
75 | const struct squashfs_decompressor *squashfs_lookup_decompressor(int id) | |
76 | { | |
77 | int i; | |
78 | ||
79 | for (i = 0; decompressor[i]->id; i++) | |
80 | if (id == decompressor[i]->id) | |
81 | break; | |
82 | ||
83 | return decompressor[i]; | |
84 | } | |
b7fc0ff0 PL |
85 | |
86 | ||
9508c6b9 | 87 | static void *get_comp_opts(struct super_block *sb, unsigned short flags) |
b7fc0ff0 PL |
88 | { |
89 | struct squashfs_sb_info *msblk = sb->s_fs_info; | |
9508c6b9 | 90 | void *buffer = NULL, *comp_opts; |
846b730e | 91 | struct squashfs_page_actor *actor = NULL; |
b7fc0ff0 PL |
92 | int length = 0; |
93 | ||
94 | /* | |
95 | * Read decompressor specific options from file system if present | |
96 | */ | |
97 | if (SQUASHFS_COMP_OPTS(flags)) { | |
98 | buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL); | |
9508c6b9 PL |
99 | if (buffer == NULL) { |
100 | comp_opts = ERR_PTR(-ENOMEM); | |
101 | goto out; | |
102 | } | |
b7fc0ff0 | 103 | |
846b730e PL |
104 | actor = squashfs_page_actor_init(&buffer, 1, 0); |
105 | if (actor == NULL) { | |
106 | comp_opts = ERR_PTR(-ENOMEM); | |
107 | goto out; | |
108 | } | |
109 | ||
110 | length = squashfs_read_data(sb, | |
111 | sizeof(struct squashfs_super_block), 0, NULL, actor); | |
b7fc0ff0 PL |
112 | |
113 | if (length < 0) { | |
9508c6b9 PL |
114 | comp_opts = ERR_PTR(length); |
115 | goto out; | |
b7fc0ff0 PL |
116 | } |
117 | } | |
118 | ||
9508c6b9 | 119 | comp_opts = squashfs_comp_opts(msblk, buffer, length); |
b7fc0ff0 | 120 | |
9508c6b9 | 121 | out: |
846b730e | 122 | kfree(actor); |
b7fc0ff0 | 123 | kfree(buffer); |
9508c6b9 PL |
124 | return comp_opts; |
125 | } | |
126 | ||
127 | ||
128 | void *squashfs_decompressor_setup(struct super_block *sb, unsigned short flags) | |
129 | { | |
130 | struct squashfs_sb_info *msblk = sb->s_fs_info; | |
131 | void *stream, *comp_opts = get_comp_opts(sb, flags); | |
132 | ||
133 | if (IS_ERR(comp_opts)) | |
134 | return comp_opts; | |
135 | ||
136 | stream = squashfs_decompressor_create(msblk, comp_opts); | |
137 | if (IS_ERR(stream)) | |
138 | kfree(comp_opts); | |
b7fc0ff0 | 139 | |
9508c6b9 | 140 | return stream; |
b7fc0ff0 | 141 | } |