Commit | Line | Data |
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68252eb5 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
4c0f0bb2 PL |
2 | /* |
3 | * Squashfs - a compressed read only filesystem for Linux | |
4 | * | |
5 | * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 | |
d7f2ff67 | 6 | * Phillip Lougher <phillip@squashfs.org.uk> |
4c0f0bb2 | 7 | * |
4c0f0bb2 PL |
8 | * decompressor.c |
9 | */ | |
10 | ||
11 | #include <linux/types.h> | |
12 | #include <linux/mutex.h> | |
b7fc0ff0 | 13 | #include <linux/slab.h> |
4c0f0bb2 PL |
14 | #include <linux/buffer_head.h> |
15 | ||
16 | #include "squashfs_fs.h" | |
17 | #include "squashfs_fs_sb.h" | |
4c0f0bb2 PL |
18 | #include "decompressor.h" |
19 | #include "squashfs.h" | |
846b730e | 20 | #include "page_actor.h" |
4c0f0bb2 PL |
21 | |
22 | /* | |
23 | * This file (and decompressor.h) implements a decompressor framework for | |
24 | * Squashfs, allowing multiple decompressors to be easily supported | |
25 | */ | |
26 | ||
dc325678 | 27 | static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = { |
9508c6b9 | 28 | NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0 |
dc325678 PL |
29 | }; |
30 | ||
62421645 PL |
31 | #ifndef CONFIG_SQUASHFS_LZ4 |
32 | static const struct squashfs_decompressor squashfs_lz4_comp_ops = { | |
33 | NULL, NULL, NULL, NULL, LZ4_COMPRESSION, "lz4", 0 | |
34 | }; | |
35 | #endif | |
36 | ||
79cb8ced | 37 | #ifndef CONFIG_SQUASHFS_LZO |
01a678c5 | 38 | static const struct squashfs_decompressor squashfs_lzo_comp_ops = { |
9508c6b9 | 39 | NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0 |
dc325678 | 40 | }; |
79cb8ced | 41 | #endif |
dc325678 | 42 | |
7a43ae52 PL |
43 | #ifndef CONFIG_SQUASHFS_XZ |
44 | static const struct squashfs_decompressor squashfs_xz_comp_ops = { | |
9508c6b9 | 45 | NULL, NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0 |
7a43ae52 PL |
46 | }; |
47 | #endif | |
48 | ||
cc6d3497 PL |
49 | #ifndef CONFIG_SQUASHFS_ZLIB |
50 | static const struct squashfs_decompressor squashfs_zlib_comp_ops = { | |
9508c6b9 | 51 | NULL, NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0 |
cc6d3497 PL |
52 | }; |
53 | #endif | |
54 | ||
87bf54bb SP |
55 | #ifndef CONFIG_SQUASHFS_ZSTD |
56 | static const struct squashfs_decompressor squashfs_zstd_comp_ops = { | |
57 | NULL, NULL, NULL, NULL, ZSTD_COMPRESSION, "zstd", 0 | |
58 | }; | |
59 | #endif | |
60 | ||
4c0f0bb2 | 61 | static const struct squashfs_decompressor squashfs_unknown_comp_ops = { |
9508c6b9 | 62 | NULL, NULL, NULL, NULL, 0, "unknown", 0 |
4c0f0bb2 PL |
63 | }; |
64 | ||
65 | static const struct squashfs_decompressor *decompressor[] = { | |
66 | &squashfs_zlib_comp_ops, | |
62421645 | 67 | &squashfs_lz4_comp_ops, |
79cb8ced | 68 | &squashfs_lzo_comp_ops, |
7a43ae52 | 69 | &squashfs_xz_comp_ops, |
01a678c5 | 70 | &squashfs_lzma_unsupported_comp_ops, |
87bf54bb | 71 | &squashfs_zstd_comp_ops, |
4c0f0bb2 PL |
72 | &squashfs_unknown_comp_ops |
73 | }; | |
74 | ||
75 | ||
76 | const struct squashfs_decompressor *squashfs_lookup_decompressor(int id) | |
77 | { | |
78 | int i; | |
79 | ||
80 | for (i = 0; decompressor[i]->id; i++) | |
81 | if (id == decompressor[i]->id) | |
82 | break; | |
83 | ||
84 | return decompressor[i]; | |
85 | } | |
b7fc0ff0 PL |
86 | |
87 | ||
9508c6b9 | 88 | static void *get_comp_opts(struct super_block *sb, unsigned short flags) |
b7fc0ff0 PL |
89 | { |
90 | struct squashfs_sb_info *msblk = sb->s_fs_info; | |
9508c6b9 | 91 | void *buffer = NULL, *comp_opts; |
846b730e | 92 | struct squashfs_page_actor *actor = NULL; |
b7fc0ff0 PL |
93 | int length = 0; |
94 | ||
95 | /* | |
96 | * Read decompressor specific options from file system if present | |
97 | */ | |
98 | if (SQUASHFS_COMP_OPTS(flags)) { | |
09cbfeaf | 99 | buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); |
9508c6b9 PL |
100 | if (buffer == NULL) { |
101 | comp_opts = ERR_PTR(-ENOMEM); | |
102 | goto out; | |
103 | } | |
b7fc0ff0 | 104 | |
846b730e PL |
105 | actor = squashfs_page_actor_init(&buffer, 1, 0); |
106 | if (actor == NULL) { | |
107 | comp_opts = ERR_PTR(-ENOMEM); | |
108 | goto out; | |
109 | } | |
110 | ||
111 | length = squashfs_read_data(sb, | |
112 | sizeof(struct squashfs_super_block), 0, NULL, actor); | |
b7fc0ff0 PL |
113 | |
114 | if (length < 0) { | |
9508c6b9 PL |
115 | comp_opts = ERR_PTR(length); |
116 | goto out; | |
b7fc0ff0 PL |
117 | } |
118 | } | |
119 | ||
9508c6b9 | 120 | comp_opts = squashfs_comp_opts(msblk, buffer, length); |
b7fc0ff0 | 121 | |
9508c6b9 | 122 | out: |
846b730e | 123 | kfree(actor); |
b7fc0ff0 | 124 | kfree(buffer); |
9508c6b9 PL |
125 | return comp_opts; |
126 | } | |
127 | ||
128 | ||
129 | void *squashfs_decompressor_setup(struct super_block *sb, unsigned short flags) | |
130 | { | |
131 | struct squashfs_sb_info *msblk = sb->s_fs_info; | |
132 | void *stream, *comp_opts = get_comp_opts(sb, flags); | |
133 | ||
134 | if (IS_ERR(comp_opts)) | |
135 | return comp_opts; | |
136 | ||
80f78409 | 137 | stream = msblk->thread_ops->create(msblk, comp_opts); |
9508c6b9 PL |
138 | if (IS_ERR(stream)) |
139 | kfree(comp_opts); | |
b7fc0ff0 | 140 | |
9508c6b9 | 141 | return stream; |
b7fc0ff0 | 142 | } |