source: src/linux/universal/linux-4.9/fs/squashfs/lzo_wrapper.c @ 31630

Last change on this file since 31630 was 31630, checked in by brainslayer, 10 days ago

new fs is compatible with standard squashfs, just smaller

File size: 3.0 KB
Line 
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
36struct squashfs_lzo {
37        void    *input;
38        void    *output;
39};
40
41static 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
57failed2:
58        vfree(stream->input);
59failed:
60        ERROR("Failed to allocate lzo workspace\n");
61        kfree(stream);
62        return ERR_PTR(-ENOMEM);
63}
64
65
66static 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
78static 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
119failed:
120        return -EIO;
121}
122
123const 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};
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