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1/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
5 * Phillip Lougher <phillip@squashfs.org.uk>
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 * xz_wrapper.c
22 */
23
24
25#include <linux/mutex.h>
26#include <linux/buffer_head.h>
27#include <linux/slab.h>
28#include <linux/xz.h>
29#include <linux/bitops.h>
30
31#include "squashfs_fs.h"
32#include "squashfs_fs_sb.h"
33#include "squashfs.h"
34#include "decompressor.h"
35
36struct squashfs_xz {
37 struct xz_dec *state;
38 struct xz_buf buf;
39};
40
41struct comp_opts {
42 __le32 dictionary_size;
43 __le32 flags;
44};
45
46static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff,
47 int len)
48{
49 struct comp_opts *comp_opts = buff;
50 struct squashfs_xz *stream;
51 int dict_size = msblk->block_size;
52 int err, n;
53
54 if (comp_opts) {
55 /* check compressor options are the expected length */
56 if (len < sizeof(*comp_opts)) {
57 err = -EIO;
58 goto failed;
59 }
60
61 dict_size = le32_to_cpu(comp_opts->dictionary_size);
62
63 /* the dictionary size should be 2^n or 2^n+2^(n+1) */
64 n = ffs(dict_size) - 1;
65 if (dict_size != (1 << n) && dict_size != (1 << n) +
66 (1 << (n + 1))) {
67 err = -EIO;
68 goto failed;
69 }
70 }
71
72 dict_size = max_t(int, dict_size, SQUASHFS_METADATA_SIZE);
73
74 stream = kmalloc(sizeof(*stream), GFP_KERNEL);
75 if (stream == NULL) {
76 err = -ENOMEM;
77 goto failed;
78 }
79
80 stream->state = xz_dec_init(XZ_PREALLOC, dict_size);
81 if (stream->state == NULL) {
82 kfree(stream);
83 err = -ENOMEM;
84 goto failed;
85 }
86
87 return stream;
88
89failed:
90 ERROR("Failed to initialise xz decompressor\n");
91 return ERR_PTR(err);
92}
93
94
95static void squashfs_xz_free(void *strm)
96{
97 struct squashfs_xz *stream = strm;
98
99 if (stream) {
100 xz_dec_end(stream->state);
101 kfree(stream);
102 }
103}
104
105
106static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void **buffer,
107 struct buffer_head **bh, int b, int offset, int length, int srclength,
108 int pages)
109{
110 enum xz_ret xz_err;
111 int avail, total = 0, k = 0, page = 0;
112 struct squashfs_xz *stream = msblk->stream;
113
114 mutex_lock(&msblk->read_data_mutex);
115
116 xz_dec_reset(stream->state);
117 stream->buf.in_pos = 0;
118 stream->buf.in_size = 0;
119 stream->buf.out_pos = 0;
120 stream->buf.out_size = PAGE_CACHE_SIZE;
121 stream->buf.out = buffer[page++];
122
123 do {
124 if (stream->buf.in_pos == stream->buf.in_size && k < b) {
125 avail = min(length, msblk->devblksize - offset);
126 length -= avail;
127 wait_on_buffer(bh[k]);
128 if (!buffer_uptodate(bh[k]))
129 goto release_mutex;
130
131 stream->buf.in = bh[k]->b_data + offset;
132 stream->buf.in_size = avail;
133 stream->buf.in_pos = 0;
134 offset = 0;
135 }
136
137 if (stream->buf.out_pos == stream->buf.out_size
138 && page < pages) {
139 stream->buf.out = buffer[page++];
140 stream->buf.out_pos = 0;
141 total += PAGE_CACHE_SIZE;
142 }
143
144 xz_err = xz_dec_run(stream->state, &stream->buf);
145
146 if (stream->buf.in_pos == stream->buf.in_size && k < b)
147 put_bh(bh[k++]);
148 } while (xz_err == XZ_OK);
149
150 if (xz_err != XZ_STREAM_END) {
151 ERROR("xz_dec_run error, data probably corrupt\n");
152 goto release_mutex;
153 }
154
155 if (k < b) {
156 ERROR("xz_uncompress error, input remaining\n");
157 goto release_mutex;
158 }
159
160 total += stream->buf.out_pos;
161 mutex_unlock(&msblk->read_data_mutex);
162 return total;
163
164release_mutex:
165 mutex_unlock(&msblk->read_data_mutex);
166
167 for (; k < b; k++)
168 put_bh(bh[k]);
169
170 return -EIO;
171}
172
173const struct squashfs_decompressor squashfs_xz_comp_ops = {
174 .init = squashfs_xz_init,
175 .free = squashfs_xz_free,
176 .decompress = squashfs_xz_uncompress,
177 .id = XZ_COMPRESSION,
178 .name = "xz",
179 .supported = 1
180};
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Squashfs - a compressed read only filesystem for Linux
4 *
5 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
6 * Phillip Lougher <phillip@squashfs.org.uk>
7 *
8 * xz_wrapper.c
9 */
10
11
12#include <linux/mutex.h>
13#include <linux/bio.h>
14#include <linux/slab.h>
15#include <linux/xz.h>
16#include <linux/bitops.h>
17
18#include "squashfs_fs.h"
19#include "squashfs_fs_sb.h"
20#include "squashfs.h"
21#include "decompressor.h"
22#include "page_actor.h"
23
24struct squashfs_xz {
25 struct xz_dec *state;
26 struct xz_buf buf;
27};
28
29struct disk_comp_opts {
30 __le32 dictionary_size;
31 __le32 flags;
32};
33
34struct comp_opts {
35 int dict_size;
36};
37
38static void *squashfs_xz_comp_opts(struct squashfs_sb_info *msblk,
39 void *buff, int len)
40{
41 struct disk_comp_opts *comp_opts = buff;
42 struct comp_opts *opts;
43 int err = 0, n;
44
45 opts = kmalloc(sizeof(*opts), GFP_KERNEL);
46 if (opts == NULL) {
47 err = -ENOMEM;
48 goto out2;
49 }
50
51 if (comp_opts) {
52 /* check compressor options are the expected length */
53 if (len < sizeof(*comp_opts)) {
54 err = -EIO;
55 goto out;
56 }
57
58 opts->dict_size = le32_to_cpu(comp_opts->dictionary_size);
59
60 /* the dictionary size should be 2^n or 2^n+2^(n+1) */
61 n = ffs(opts->dict_size) - 1;
62 if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) +
63 (1 << (n + 1))) {
64 err = -EIO;
65 goto out;
66 }
67 } else
68 /* use defaults */
69 opts->dict_size = max_t(int, msblk->block_size,
70 SQUASHFS_METADATA_SIZE);
71
72 return opts;
73
74out:
75 kfree(opts);
76out2:
77 return ERR_PTR(err);
78}
79
80
81static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff)
82{
83 struct comp_opts *comp_opts = buff;
84 struct squashfs_xz *stream;
85 int err;
86
87 stream = kmalloc(sizeof(*stream), GFP_KERNEL);
88 if (stream == NULL) {
89 err = -ENOMEM;
90 goto failed;
91 }
92
93 stream->state = xz_dec_init(XZ_PREALLOC, comp_opts->dict_size);
94 if (stream->state == NULL) {
95 kfree(stream);
96 err = -ENOMEM;
97 goto failed;
98 }
99
100 return stream;
101
102failed:
103 ERROR("Failed to initialise xz decompressor\n");
104 return ERR_PTR(err);
105}
106
107
108static void squashfs_xz_free(void *strm)
109{
110 struct squashfs_xz *stream = strm;
111
112 if (stream) {
113 xz_dec_end(stream->state);
114 kfree(stream);
115 }
116}
117
118
119static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
120 struct bio *bio, int offset, int length,
121 struct squashfs_page_actor *output)
122{
123 struct bvec_iter_all iter_all = {};
124 struct bio_vec *bvec = bvec_init_iter_all(&iter_all);
125 int total = 0, error = 0;
126 struct squashfs_xz *stream = strm;
127
128 xz_dec_reset(stream->state);
129 stream->buf.in_pos = 0;
130 stream->buf.in_size = 0;
131 stream->buf.out_pos = 0;
132 stream->buf.out_size = PAGE_SIZE;
133 stream->buf.out = squashfs_first_page(output);
134 if (IS_ERR(stream->buf.out)) {
135 error = PTR_ERR(stream->buf.out);
136 goto finish;
137 }
138
139 for (;;) {
140 enum xz_ret xz_err;
141
142 if (stream->buf.in_pos == stream->buf.in_size) {
143 const void *data;
144 int avail;
145
146 if (!bio_next_segment(bio, &iter_all)) {
147 /* XZ_STREAM_END must be reached. */
148 error = -EIO;
149 break;
150 }
151
152 avail = min(length, ((int)bvec->bv_len) - offset);
153 data = bvec_virt(bvec);
154 length -= avail;
155 stream->buf.in = data + offset;
156 stream->buf.in_size = avail;
157 stream->buf.in_pos = 0;
158 offset = 0;
159 }
160
161 if (stream->buf.out_pos == stream->buf.out_size) {
162 stream->buf.out = squashfs_next_page(output);
163 if (IS_ERR(stream->buf.out)) {
164 error = PTR_ERR(stream->buf.out);
165 break;
166 } else if (stream->buf.out != NULL) {
167 stream->buf.out_pos = 0;
168 total += PAGE_SIZE;
169 }
170 }
171
172 xz_err = xz_dec_run(stream->state, &stream->buf);
173 if (xz_err == XZ_STREAM_END)
174 break;
175 if (xz_err != XZ_OK) {
176 error = -EIO;
177 break;
178 }
179 }
180
181finish:
182 squashfs_finish_page(output);
183
184 return error ? error : total + stream->buf.out_pos;
185}
186
187const struct squashfs_decompressor squashfs_xz_comp_ops = {
188 .init = squashfs_xz_init,
189 .comp_opts = squashfs_xz_comp_opts,
190 .free = squashfs_xz_free,
191 .decompress = squashfs_xz_uncompress,
192 .id = XZ_COMPRESSION,
193 .name = "xz",
194 .alloc_buffer = 1,
195 .supported = 1
196};