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
35 struct squashfs_lzo {
36 void *input;
37 void *output;
38 };
39
lzo_init(struct squashfs_sb_info * msblk,void * buff,int len)40 static void *lzo_init(struct squashfs_sb_info *msblk, void *buff, int len)
41 {
42 int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
43
44 struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
45 if (stream == NULL)
46 goto failed;
47 stream->input = vmalloc(block_size);
48 if (stream->input == NULL)
49 goto failed;
50 stream->output = vmalloc(block_size);
51 if (stream->output == NULL)
52 goto failed2;
53
54 return stream;
55
56 failed2:
57 vfree(stream->input);
58 failed:
59 ERROR("Failed to allocate lzo workspace\n");
60 kfree(stream);
61 return ERR_PTR(-ENOMEM);
62 }
63
64
lzo_free(void * strm)65 static void lzo_free(void *strm)
66 {
67 struct squashfs_lzo *stream = strm;
68
69 if (stream) {
70 vfree(stream->input);
71 vfree(stream->output);
72 }
73 kfree(stream);
74 }
75
76
lzo_uncompress(struct squashfs_sb_info * msblk,void ** buffer,struct buffer_head ** bh,int b,int offset,int length,int srclength,int pages)77 static int lzo_uncompress(struct squashfs_sb_info *msblk, void **buffer,
78 struct buffer_head **bh, int b, int offset, int length, int srclength,
79 int pages)
80 {
81 struct squashfs_lzo *stream = msblk->stream;
82 void *buff = stream->input;
83 int avail, i, bytes = length, res;
84 size_t out_len = srclength;
85
86 mutex_lock(&msblk->read_data_mutex);
87
88 for (i = 0; i < b; i++) {
89 wait_on_buffer(bh[i]);
90 if (!buffer_uptodate(bh[i]))
91 goto block_release;
92
93 avail = min(bytes, msblk->devblksize - offset);
94 memcpy(buff, bh[i]->b_data + offset, avail);
95 buff += avail;
96 bytes -= avail;
97 offset = 0;
98 put_bh(bh[i]);
99 }
100
101 res = lzo1x_decompress_safe(stream->input, (size_t)length,
102 stream->output, &out_len);
103 if (res != LZO_E_OK)
104 goto failed;
105
106 res = bytes = (int)out_len;
107 for (i = 0, buff = stream->output; bytes && i < pages; i++) {
108 avail = min_t(int, bytes, PAGE_CACHE_SIZE);
109 memcpy(buffer[i], buff, avail);
110 buff += avail;
111 bytes -= avail;
112 }
113
114 mutex_unlock(&msblk->read_data_mutex);
115 return res;
116
117 block_release:
118 for (; i < b; i++)
119 put_bh(bh[i]);
120
121 failed:
122 mutex_unlock(&msblk->read_data_mutex);
123
124 ERROR("lzo decompression failed, data probably corrupt\n");
125 return -EIO;
126 }
127
128 const struct squashfs_decompressor squashfs_lzo_comp_ops = {
129 .init = lzo_init,
130 .free = lzo_free,
131 .decompress = lzo_uncompress,
132 .id = LZO_COMPRESSION,
133 .name = "lzo",
134 .supported = 1
135 };
136