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.h"
33 #include "decompressor.h"
34 #include "page_actor.h"
35
36 struct squashfs_lzo {
37 void *input;
38 void *output;
39 };
40
lzo_init(struct squashfs_sb_info * msblk,void * buff)41 static void *lzo_init(struct squashfs_sb_info *msblk, void *buff)
42 {
43 int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
44
45 struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
46 if (stream == NULL)
47 goto failed;
48 stream->input = vmalloc(block_size);
49 if (stream->input == NULL)
50 goto failed;
51 stream->output = vmalloc(block_size);
52 if (stream->output == NULL)
53 goto failed2;
54
55 return stream;
56
57 failed2:
58 vfree(stream->input);
59 failed:
60 ERROR("Failed to allocate lzo workspace\n");
61 kfree(stream);
62 return ERR_PTR(-ENOMEM);
63 }
64
65
lzo_free(void * strm)66 static void lzo_free(void *strm)
67 {
68 struct squashfs_lzo *stream = strm;
69
70 if (stream) {
71 vfree(stream->input);
72 vfree(stream->output);
73 }
74 kfree(stream);
75 }
76
77
lzo_uncompress(struct squashfs_sb_info * msblk,void * strm,struct buffer_head ** bh,int b,int offset,int length,struct squashfs_page_actor * output)78 static int lzo_uncompress(struct squashfs_sb_info *msblk, void *strm,
79 struct buffer_head **bh, int b, int offset, int length,
80 struct squashfs_page_actor *output)
81 {
82 struct squashfs_lzo *stream = strm;
83 void *buff = stream->input, *data;
84 int avail, i, bytes = length, res;
85 size_t out_len = output->length;
86
87 for (i = 0; i < b; i++) {
88 avail = min(bytes, msblk->devblksize - offset);
89 memcpy(buff, bh[i]->b_data + offset, avail);
90 buff += avail;
91 bytes -= avail;
92 offset = 0;
93 put_bh(bh[i]);
94 }
95
96 res = lzo1x_decompress_safe(stream->input, (size_t)length,
97 stream->output, &out_len);
98 if (res != LZO_E_OK)
99 goto failed;
100
101 res = bytes = (int)out_len;
102 data = squashfs_first_page(output);
103 buff = stream->output;
104 while (data) {
105 if (bytes <= PAGE_SIZE) {
106 memcpy(data, buff, bytes);
107 break;
108 } else {
109 memcpy(data, buff, PAGE_SIZE);
110 buff += PAGE_SIZE;
111 bytes -= PAGE_SIZE;
112 data = squashfs_next_page(output);
113 }
114 }
115 squashfs_finish_page(output);
116
117 return res;
118
119 failed:
120 return -EIO;
121 }
122
123 const struct squashfs_decompressor squashfs_lzo_comp_ops = {
124 .init = lzo_init,
125 .free = lzo_free,
126 .decompress = lzo_uncompress,
127 .id = LZO_COMPRESSION,
128 .name = "lzo",
129 .supported = 1
130 };
131
