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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Squashfs - a compressed read only filesystem for Linux
*
* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
* Phillip Lougher <phillip@squashfs.org.uk>
*
* xz_wrapper.c
*/
#include <linux/mutex.h>
#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/xz.h>
#include <linux/bitops.h>
#include "squashfs_fs.h"
#include "squashfs_fs_sb.h"
#include "squashfs.h"
#include "decompressor.h"
#include "page_actor.h"
struct squashfs_xz {
struct xz_dec *state;
struct xz_buf buf;
};
struct disk_comp_opts {
__le32 dictionary_size;
__le32 flags;
};
struct comp_opts {
int dict_size;
};
static void *squashfs_xz_comp_opts(struct squashfs_sb_info *msblk,
void *buff, int len)
{
struct disk_comp_opts *comp_opts = buff;
struct comp_opts *opts;
int err = 0, n;
opts = kmalloc(sizeof(*opts), GFP_KERNEL);
if (opts == NULL) {
err = -ENOMEM;
goto out2;
}
if (comp_opts) {
/* check compressor options are the expected length */
if (len < sizeof(*comp_opts)) {
err = -EIO;
goto out;
}
opts->dict_size = le32_to_cpu(comp_opts->dictionary_size);
/* the dictionary size should be 2^n or 2^n+2^(n+1) */
n = ffs(opts->dict_size) - 1;
if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) +
(1 << (n + 1))) {
err = -EIO;
goto out;
}
} else
/* use defaults */
opts->dict_size = max_t(int, msblk->block_size,
SQUASHFS_METADATA_SIZE);
return opts;
out:
kfree(opts);
out2:
return ERR_PTR(err);
}
static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff)
{
struct comp_opts *comp_opts = buff;
struct squashfs_xz *stream;
int err;
stream = kmalloc(sizeof(*stream), GFP_KERNEL);
if (stream == NULL) {
err = -ENOMEM;
goto failed;
}
stream->state = xz_dec_init(XZ_PREALLOC, comp_opts->dict_size);
if (stream->state == NULL) {
kfree(stream);
err = -ENOMEM;
goto failed;
}
return stream;
failed:
ERROR("Failed to initialise xz decompressor\n");
return ERR_PTR(err);
}
static void squashfs_xz_free(void *strm)
{
struct squashfs_xz *stream = strm;
if (stream) {
xz_dec_end(stream->state);
kfree(stream);
}
}
static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
struct bio *bio, int offset, int length,
struct squashfs_page_actor *output)
{
struct bvec_iter_all iter_all = {};
struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
int total = 0, error = 0;
struct squashfs_xz *stream = strm;
xz_dec_reset(stream->state);
stream->buf.in_pos = 0;
stream->buf.in_size = 0;
stream->buf.out_pos = 0;
stream->buf.out_size = PAGE_SIZE;
stream->buf.out = squashfs_first_page(output);
if (IS_ERR(stream->buf.out)) {
error = PTR_ERR(stream->buf.out);
goto finish;
}
for (;;) {
enum xz_ret xz_err;
if (stream->buf.in_pos == stream->buf.in_size) {
const void *data;
int avail;
if (!bio_next_segment(bio, &iter_all)) {
/* XZ_STREAM_END must be reached. */
error = -EIO;
break;
}
avail = min(length, ((int)bvec->bv_len) - offset);
data = bvec_virt(bvec);
length -= avail;
stream->buf.in = data + offset;
stream->buf.in_size = avail;
stream->buf.in_pos = 0;
offset = 0;
}
if (stream->buf.out_pos == stream->buf.out_size) {
stream->buf.out = squashfs_next_page(output);
if (IS_ERR(stream->buf.out)) {
error = PTR_ERR(stream->buf.out);
break;
} else if (stream->buf.out != NULL) {
stream->buf.out_pos = 0;
total += PAGE_SIZE;
}
}
xz_err = xz_dec_run(stream->state, &stream->buf);
if (xz_err == XZ_STREAM_END)
break;
if (xz_err != XZ_OK) {
error = -EIO;
break;
}
}
finish:
squashfs_finish_page(output);
return error ? error : total + stream->buf.out_pos;
}
const struct squashfs_decompressor squashfs_xz_comp_ops = {
.init = squashfs_xz_init,
.comp_opts = squashfs_xz_comp_opts,
.free = squashfs_xz_free,
.decompress = squashfs_xz_uncompress,
.id = XZ_COMPRESSION,
.name = "xz",
.alloc_buffer = 1,
.supported = 1
};
|
