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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#include "page_actor.h"
36
37struct squashfs_xz {
38 struct xz_dec *state;
39 struct xz_buf buf;
40};
41
42struct disk_comp_opts {
43 __le32 dictionary_size;
44 __le32 flags;
45};
46
47struct comp_opts {
48 int dict_size;
49};
50
51static void *squashfs_xz_comp_opts(struct squashfs_sb_info *msblk,
52 void *buff, int len)
53{
54 struct disk_comp_opts *comp_opts = buff;
55 struct comp_opts *opts;
56 int err = 0, n;
57
58 opts = kmalloc(sizeof(*opts), GFP_KERNEL);
59 if (opts == NULL) {
60 err = -ENOMEM;
61 goto out2;
62 }
63
64 if (comp_opts) {
65 /* check compressor options are the expected length */
66 if (len < sizeof(*comp_opts)) {
67 err = -EIO;
68 goto out;
69 }
70
71 opts->dict_size = le32_to_cpu(comp_opts->dictionary_size);
72
73 /* the dictionary size should be 2^n or 2^n+2^(n+1) */
74 n = ffs(opts->dict_size) - 1;
75 if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) +
76 (1 << (n + 1))) {
77 err = -EIO;
78 goto out;
79 }
80 } else
81 /* use defaults */
82 opts->dict_size = max_t(int, msblk->block_size,
83 SQUASHFS_METADATA_SIZE);
84
85 return opts;
86
87out:
88 kfree(opts);
89out2:
90 return ERR_PTR(err);
91}
92
93
94static void *squashfs_xz_init(struct squashfs_sb_info *msblk, void *buff)
95{
96 struct comp_opts *comp_opts = buff;
97 struct squashfs_xz *stream;
98 int err;
99
100 stream = kmalloc(sizeof(*stream), GFP_KERNEL);
101 if (stream == NULL) {
102 err = -ENOMEM;
103 goto failed;
104 }
105
106 stream->state = xz_dec_init(XZ_PREALLOC, comp_opts->dict_size);
107 if (stream->state == NULL) {
108 kfree(stream);
109 err = -ENOMEM;
110 goto failed;
111 }
112
113 return stream;
114
115failed:
116 ERROR("Failed to initialise xz decompressor\n");
117 return ERR_PTR(err);
118}
119
120
121static void squashfs_xz_free(void *strm)
122{
123 struct squashfs_xz *stream = strm;
124
125 if (stream) {
126 xz_dec_end(stream->state);
127 kfree(stream);
128 }
129}
130
131
132static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
133 struct buffer_head **bh, int b, int offset, int length,
134 struct squashfs_page_actor *output)
135{
136 enum xz_ret xz_err;
137 int avail, total = 0, k = 0;
138 struct squashfs_xz *stream = strm;
139
140 xz_dec_reset(stream->state);
141 stream->buf.in_pos = 0;
142 stream->buf.in_size = 0;
143 stream->buf.out_pos = 0;
144 stream->buf.out_size = PAGE_SIZE;
145 stream->buf.out = squashfs_first_page(output);
146
147 do {
148 if (stream->buf.in_pos == stream->buf.in_size && k < b) {
149 avail = min(length, msblk->devblksize - offset);
150 length -= avail;
151 stream->buf.in = bh[k]->b_data + offset;
152 stream->buf.in_size = avail;
153 stream->buf.in_pos = 0;
154 offset = 0;
155 }
156
157 if (stream->buf.out_pos == stream->buf.out_size) {
158 stream->buf.out = squashfs_next_page(output);
159 if (stream->buf.out != NULL) {
160 stream->buf.out_pos = 0;
161 total += PAGE_SIZE;
162 }
163 }
164
165 xz_err = xz_dec_run(stream->state, &stream->buf);
166
167 if (stream->buf.in_pos == stream->buf.in_size && k < b)
168 put_bh(bh[k++]);
169 } while (xz_err == XZ_OK);
170
171 squashfs_finish_page(output);
172
173 if (xz_err != XZ_STREAM_END || k < b)
174 goto out;
175
176 return total + stream->buf.out_pos;
177
178out:
179 for (; k < b; k++)
180 put_bh(bh[k]);
181
182 return -EIO;
183}
184
185const struct squashfs_decompressor squashfs_xz_comp_ops = {
186 .init = squashfs_xz_init,
187 .comp_opts = squashfs_xz_comp_opts,
188 .free = squashfs_xz_free,
189 .decompress = squashfs_xz_uncompress,
190 .id = XZ_COMPRESSION,
191 .name = "xz",
192 .supported = 1
193};
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};