2 * Squashfs - a compressed read only filesystem for Linux
4 * Copyright (c) 2010 LG Electronics
5 * Chan Jeong <chan.jeong@lge.com>
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.
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.
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.
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>
30 #include "squashfs_fs.h"
31 #include "squashfs_fs_sb.h"
32 #include "squashfs_fs_i.h"
34 #include "decompressor.h"
41 static void *lzo_init(struct squashfs_sb_info *msblk)
43 int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
45 struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
48 stream->input = vmalloc(block_size);
49 if (stream->input == NULL)
51 stream->output = vmalloc(block_size);
52 if (stream->output == NULL)
60 ERROR("Failed to allocate lzo workspace\n");
66 static void lzo_free(void *strm)
68 struct squashfs_lzo *stream = strm;
72 vfree(stream->output);
78 static int lzo_uncompress(struct squashfs_sb_info *msblk, void **buffer,
79 struct buffer_head **bh, int b, int offset, int length, int srclength,
82 struct squashfs_lzo *stream = msblk->stream;
83 void *buff = stream->input;
84 int avail, i, bytes = length, res;
85 size_t out_len = srclength;
87 mutex_lock(&msblk->read_data_mutex);
89 for (i = 0; i < b; i++) {
90 wait_on_buffer(bh[i]);
91 if (!buffer_uptodate(bh[i]))
94 avail = min(bytes, msblk->devblksize - offset);
95 memcpy(buff, bh[i]->b_data + offset, avail);
102 res = lzo1x_decompress_safe(stream->input, (size_t)length,
103 stream->output, &out_len);
107 res = bytes = (int)out_len;
108 for (i = 0, buff = stream->output; bytes && i < pages; i++) {
109 avail = min_t(int, bytes, PAGE_CACHE_SIZE);
110 memcpy(buffer[i], buff, avail);
115 mutex_unlock(&msblk->read_data_mutex);
123 mutex_unlock(&msblk->read_data_mutex);
125 ERROR("lzo decompression failed, data probably corrupt\n");
129 const struct squashfs_decompressor squashfs_lzo_comp_ops = {
132 .decompress = lzo_uncompress,
133 .id = LZO_COMPRESSION,