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Phillip Lougher81bb8de2010-12-09 02:02:29 +00001/*
2 * Squashfs - a compressed read only filesystem for Linux
3 *
4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Phillip Lougherd7f2ff62011-05-26 10:39:56 +01005 * Phillip Lougher <phillip@squashfs.org.uk>
Phillip Lougher81bb8de2010-12-09 02:02:29 +00006 *
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>
Phillip Lougherff750312011-02-28 15:31:46 +000029#include <linux/bitops.h>
Phillip Lougher81bb8de2010-12-09 02:02:29 +000030
31#include "squashfs_fs.h"
32#include "squashfs_fs_sb.h"
Phillip Lougher81bb8de2010-12-09 02:02:29 +000033#include "squashfs.h"
34#include "decompressor.h"
Phillip Lougher846b7302013-11-18 02:59:12 +000035#include "page_actor.h"
Phillip Lougher81bb8de2010-12-09 02:02:29 +000036
37struct squashfs_xz {
38 struct xz_dec *state;
39 struct xz_buf buf;
40};
41
Phillip Lougher9508c6b2013-11-13 02:56:26 +000042struct disk_comp_opts {
Phillip Lougherff750312011-02-28 15:31:46 +000043 __le32 dictionary_size;
44 __le32 flags;
45};
46
Phillip Lougher9508c6b2013-11-13 02:56:26 +000047struct comp_opts {
48 int dict_size;
49};
50
51static void *squashfs_xz_comp_opts(struct squashfs_sb_info *msblk,
52 void *buff, int len)
Phillip Lougher81bb8de2010-12-09 02:02:29 +000053{
Phillip Lougher9508c6b2013-11-13 02:56:26 +000054 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 }
Phillip Lougher81bb8de2010-12-09 02:02:29 +000063
Phillip Lougherff750312011-02-28 15:31:46 +000064 if (comp_opts) {
65 /* check compressor options are the expected length */
66 if (len < sizeof(*comp_opts)) {
67 err = -EIO;
Phillip Lougher9508c6b2013-11-13 02:56:26 +000068 goto out;
Phillip Lougherff750312011-02-28 15:31:46 +000069 }
Phillip Lougher81bb8de2010-12-09 02:02:29 +000070
Phillip Lougher9508c6b2013-11-13 02:56:26 +000071 opts->dict_size = le32_to_cpu(comp_opts->dictionary_size);
Phillip Lougherff750312011-02-28 15:31:46 +000072
73 /* the dictionary size should be 2^n or 2^n+2^(n+1) */
Phillip Lougher9508c6b2013-11-13 02:56:26 +000074 n = ffs(opts->dict_size) - 1;
75 if (opts->dict_size != (1 << n) && opts->dict_size != (1 << n) +
Phillip Lougherff750312011-02-28 15:31:46 +000076 (1 << (n + 1))) {
77 err = -EIO;
Phillip Lougher9508c6b2013-11-13 02:56:26 +000078 goto out;
Phillip Lougherff750312011-02-28 15:31:46 +000079 }
Phillip Lougher9508c6b2013-11-13 02:56:26 +000080 } else
81 /* use defaults */
82 opts->dict_size = max_t(int, msblk->block_size,
83 SQUASHFS_METADATA_SIZE);
Phillip Lougherff750312011-02-28 15:31:46 +000084
Phillip Lougher9508c6b2013-11-13 02:56:26 +000085 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;
Phillip Lougherff750312011-02-28 15:31:46 +000099
100 stream = kmalloc(sizeof(*stream), GFP_KERNEL);
101 if (stream == NULL) {
102 err = -ENOMEM;
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000103 goto failed;
Phillip Lougherff750312011-02-28 15:31:46 +0000104 }
105
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000106 stream->state = xz_dec_init(XZ_PREALLOC, comp_opts->dict_size);
Phillip Lougherff750312011-02-28 15:31:46 +0000107 if (stream->state == NULL) {
108 kfree(stream);
109 err = -ENOMEM;
110 goto failed;
111 }
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000112
113 return stream;
114
115failed:
Phillip Lougherff750312011-02-28 15:31:46 +0000116 ERROR("Failed to initialise xz decompressor\n");
117 return ERR_PTR(err);
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000118}
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
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000132static int squashfs_xz_uncompress(struct squashfs_sb_info *msblk, void *strm,
Phillip Lougher846b7302013-11-18 02:59:12 +0000133 struct buffer_head **bh, int b, int offset, int length,
134 struct squashfs_page_actor *output)
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000135{
136 enum xz_ret xz_err;
Phillip Lougher846b7302013-11-18 02:59:12 +0000137 int avail, total = 0, k = 0;
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000138 struct squashfs_xz *stream = strm;
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000139
140 xz_dec_reset(stream->state);
141 stream->buf.in_pos = 0;
142 stream->buf.in_size = 0;
143 stream->buf.out_pos = 0;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300144 stream->buf.out_size = PAGE_SIZE;
Phillip Lougher846b7302013-11-18 02:59:12 +0000145 stream->buf.out = squashfs_first_page(output);
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000146
147 do {
148 if (stream->buf.in_pos == stream->buf.in_size && k < b) {
149 avail = min(length, msblk->devblksize - offset);
150 length -= avail;
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000151 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
Phillip Lougher846b7302013-11-18 02:59:12 +0000157 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;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300161 total += PAGE_SIZE;
Phillip Lougher846b7302013-11-18 02:59:12 +0000162 }
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000163 }
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
Phillip Lougher846b7302013-11-18 02:59:12 +0000171 squashfs_finish_page(output);
172
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000173 if (xz_err != XZ_STREAM_END || k < b)
174 goto out;
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000175
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000176 return total + stream->buf.out_pos;
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000177
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000178out:
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000179 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,
Phillip Lougher9508c6b2013-11-13 02:56:26 +0000187 .comp_opts = squashfs_xz_comp_opts,
Phillip Lougher81bb8de2010-12-09 02:02:29 +0000188 .free = squashfs_xz_free,
189 .decompress = squashfs_xz_uncompress,
190 .id = XZ_COMPRESSION,
191 .name = "xz",
192 .supported = 1
193};