1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2013, 2014
* Phillip Lougher <phillip@squashfs.org.uk>
*/
#include <linux/buffer_head.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/lz4.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "squashfs.h"
#include "decompressor.h"
#include "page_actor.h"
#define LZ4_LEGACY 1
struct lz4_comp_opts {
__le32 version;
__le32 flags;
};
struct squashfs_lz4 {
void *input;
void *output;
};
static void *lz4_comp_opts(struct squashfs_sb_info *msblk,
void *buff, int len)
{
struct lz4_comp_opts *comp_opts = buff;
/* LZ4 compressed filesystems always have compression options */
if (comp_opts == NULL || len < sizeof(*comp_opts))
return ERR_PTR(-EIO);
if (le32_to_cpu(comp_opts->version) != LZ4_LEGACY) {
/* LZ4 format currently used by the kernel is the 'legacy'
* format */
ERROR("Unknown LZ4 version\n");
return ERR_PTR(-EINVAL);
}
return NULL;
}
static void *lz4_init(struct squashfs_sb_info *msblk, void *buff)
{
int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
struct squashfs_lz4 *stream;
stream = kzalloc(sizeof(*stream), GFP_KERNEL);
if (stream == NULL)
goto failed;
stream->input = vmalloc(block_size);
if (stream->input == NULL)
goto failed2;
stream->output = vmalloc(block_size);
if (stream->output == NULL)
goto failed3;
return stream;
failed3:
vfree(stream->input);
failed2:
kfree(stream);
failed:
ERROR("Failed to initialise LZ4 decompressor\n");
return ERR_PTR(-ENOMEM);
}
static void lz4_free(void *strm)
{
struct squashfs_lz4 *stream = strm;
if (stream) {
vfree(stream->input);
vfree(stream->output);
}
kfree(stream);
}
static int lz4_uncompress(struct squashfs_sb_info *msblk, void *strm,
struct buffer_head **bh, int b, int offset, int length,
struct squashfs_page_actor *output)
{
struct squashfs_lz4 *stream = strm;
void *buff = stream->input, *data;
int avail, i, bytes = length, res;
for (i = 0; i < b; i++) {
avail = min(bytes, msblk->devblksize - offset);
memcpy(buff, bh[i]->b_data + offset, avail);
buff += avail;
bytes -= avail;
offset = 0;
put_bh(bh[i]);
}
res = LZ4_decompress_safe(stream->input, stream->output,
length, output->length);
if (res < 0)
return -EIO;
bytes = res;
data = squashfs_first_page(output);
buff = stream->output;
while (data) {
if (bytes <= PAGE_SIZE) {
memcpy(data, buff, bytes);
break;
}
memcpy(data, buff, PAGE_SIZE);
buff += PAGE_SIZE;
bytes -= PAGE_SIZE;
data = squashfs_next_page(output);
}
squashfs_finish_page(output);
return res;
}
const struct squashfs_decompressor squashfs_lz4_comp_ops = {
.init = lz4_init,
.comp_opts = lz4_comp_opts,
.free = lz4_free,
.decompress = lz4_uncompress,
.id = LZ4_COMPRESSION,
.name = "lz4",
.supported = 1
};
|
