Commit | Line | Data |
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79cb8ced CJ |
1 | /* |
2 | * Squashfs - a compressed read only filesystem for Linux | |
3 | * | |
4 | * Copyright (c) 2010 LG Electronics | |
5 | * Chan Jeong <chan.jeong@lge.com> | |
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 | * lzo_wrapper.c | |
22 | */ | |
23 | ||
24 | #include <linux/mutex.h> | |
25 | #include <linux/buffer_head.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/vmalloc.h> | |
28 | #include <linux/lzo.h> | |
29 | ||
30 | #include "squashfs_fs.h" | |
31 | #include "squashfs_fs_sb.h" | |
32 | #include "squashfs_fs_i.h" | |
33 | #include "squashfs.h" | |
34 | #include "decompressor.h" | |
35 | ||
36 | struct squashfs_lzo { | |
37 | void *input; | |
38 | void *output; | |
39 | }; | |
40 | ||
41 | static void *lzo_init(struct squashfs_sb_info *msblk) | |
42 | { | |
43 | struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL); | |
44 | if (stream == NULL) | |
45 | goto failed; | |
46 | stream->input = vmalloc(msblk->block_size); | |
47 | if (stream->input == NULL) | |
48 | goto failed; | |
49 | stream->output = vmalloc(msblk->block_size); | |
50 | if (stream->output == NULL) | |
51 | goto failed2; | |
52 | ||
53 | return stream; | |
54 | ||
55 | failed2: | |
56 | vfree(stream->input); | |
57 | failed: | |
58 | ERROR("Failed to allocate lzo workspace\n"); | |
59 | kfree(stream); | |
60 | return NULL; | |
61 | } | |
62 | ||
63 | ||
64 | static void lzo_free(void *strm) | |
65 | { | |
66 | struct squashfs_lzo *stream = strm; | |
67 | ||
68 | if (stream) { | |
69 | vfree(stream->input); | |
70 | vfree(stream->output); | |
71 | } | |
72 | kfree(stream); | |
73 | } | |
74 | ||
75 | ||
76 | static int lzo_uncompress(struct squashfs_sb_info *msblk, void **buffer, | |
77 | struct buffer_head **bh, int b, int offset, int length, int srclength, | |
78 | int pages) | |
79 | { | |
80 | struct squashfs_lzo *stream = msblk->stream; | |
81 | void *buff = stream->input; | |
82 | int avail, i, bytes = length, res; | |
83 | size_t out_len = msblk->block_size; | |
84 | ||
85 | mutex_lock(&msblk->read_data_mutex); | |
86 | ||
87 | for (i = 0; i < b; i++) { | |
88 | wait_on_buffer(bh[i]); | |
89 | if (!buffer_uptodate(bh[i])) | |
90 | goto block_release; | |
91 | ||
92 | avail = min(bytes, msblk->devblksize - offset); | |
93 | memcpy(buff, bh[i]->b_data + offset, avail); | |
94 | buff += avail; | |
95 | bytes -= avail; | |
96 | offset = 0; | |
97 | put_bh(bh[i]); | |
98 | } | |
99 | ||
100 | res = lzo1x_decompress_safe(stream->input, (size_t)length, | |
101 | stream->output, &out_len); | |
102 | if (res != LZO_E_OK) | |
103 | goto failed; | |
104 | ||
105 | res = bytes = (int)out_len; | |
106 | for (i = 0, buff = stream->output; bytes && i < pages; i++) { | |
107 | avail = min_t(int, bytes, PAGE_CACHE_SIZE); | |
108 | memcpy(buffer[i], buff, avail); | |
109 | buff += avail; | |
110 | bytes -= avail; | |
111 | } | |
112 | ||
113 | mutex_unlock(&msblk->read_data_mutex); | |
114 | return res; | |
115 | ||
116 | block_release: | |
117 | for (; i < b; i++) | |
118 | put_bh(bh[i]); | |
119 | ||
120 | failed: | |
121 | mutex_unlock(&msblk->read_data_mutex); | |
122 | ||
123 | ERROR("lzo decompression failed, data probably corrupt\n"); | |
124 | return -EIO; | |
125 | } | |
126 | ||
127 | const struct squashfs_decompressor squashfs_lzo_comp_ops = { | |
128 | .init = lzo_init, | |
129 | .free = lzo_free, | |
130 | .decompress = lzo_uncompress, | |
131 | .id = LZO_COMPRESSION, | |
132 | .name = "lzo", | |
133 | .supported = 1 | |
134 | }; |