tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Squashfs - a compressed read only filesystem for Linux
4 *
5 * Copyright (c) 2010 LG Electronics
6 * Chan Jeong <chan.jeong@lge.com>
7 *
8 * lzo_wrapper.c
9 */
10
11#include <linux/mutex.h>
12#include <linux/buffer_head.h>
13#include <linux/slab.h>
14#include <linux/vmalloc.h>
15#include <linux/lzo.h>
16
17#include "squashfs_fs.h"
18#include "squashfs_fs_sb.h"
19#include "squashfs.h"
20#include "decompressor.h"
21#include "page_actor.h"
22
23struct squashfs_lzo {
24 void *input;
25 void *output;
26};
27
28static void *lzo_init(struct squashfs_sb_info *msblk, void *buff)
29{
30 int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
31
32 struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
33 if (stream == NULL)
34 goto failed;
35 stream->input = vmalloc(block_size);
36 if (stream->input == NULL)
37 goto failed;
38 stream->output = vmalloc(block_size);
39 if (stream->output == NULL)
40 goto failed2;
41
42 return stream;
43
44failed2:
45 vfree(stream->input);
46failed:
47 ERROR("Failed to allocate lzo workspace\n");
48 kfree(stream);
49 return ERR_PTR(-ENOMEM);
50}
51
52
53static void lzo_free(void *strm)
54{
55 struct squashfs_lzo *stream = strm;
56
57 if (stream) {
58 vfree(stream->input);
59 vfree(stream->output);
60 }
61 kfree(stream);
62}
63
64
65static int lzo_uncompress(struct squashfs_sb_info *msblk, void *strm,
66 struct buffer_head **bh, int b, int offset, int length,
67 struct squashfs_page_actor *output)
68{
69 struct squashfs_lzo *stream = strm;
70 void *buff = stream->input, *data;
71 int avail, i, bytes = length, res;
72 size_t out_len = output->length;
73
74 for (i = 0; i < b; i++) {
75 avail = min(bytes, msblk->devblksize - offset);
76 memcpy(buff, bh[i]->b_data + offset, avail);
77 buff += avail;
78 bytes -= avail;
79 offset = 0;
80 put_bh(bh[i]);
81 }
82
83 res = lzo1x_decompress_safe(stream->input, (size_t)length,
84 stream->output, &out_len);
85 if (res != LZO_E_OK)
86 goto failed;
87
88 res = bytes = (int)out_len;
89 data = squashfs_first_page(output);
90 buff = stream->output;
91 while (data) {
92 if (bytes <= PAGE_SIZE) {
93 memcpy(data, buff, bytes);
94 break;
95 } else {
96 memcpy(data, buff, PAGE_SIZE);
97 buff += PAGE_SIZE;
98 bytes -= PAGE_SIZE;
99 data = squashfs_next_page(output);
100 }
101 }
102 squashfs_finish_page(output);
103
104 return res;
105
106failed:
107 return -EIO;
108}
109
110const struct squashfs_decompressor squashfs_lzo_comp_ops = {
111 .init = lzo_init,
112 .free = lzo_free,
113 .decompress = lzo_uncompress,
114 .id = LZO_COMPRESSION,
115 .name = "lzo",
116 .supported = 1
117};