summaryrefslogtreecommitdiff
path: root/target/linux/generic/patches-2.6.31/006-squashfs_add_lzma.patch
blob: 9fd57970f255db214321b01b1533128d2db2785a (plain)
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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
From f49e1efdd179d54e814ff2a8e8f469496583062c Mon Sep 17 00:00:00 2001
From: Phillip Lougher <phillip@lougher.demon.co.uk>
Date: Tue, 20 Oct 2009 10:54:36 +0100
Subject: [PATCH] Squashfs: add LZMA compression

Add support for LZMA compressed filesystems.  This is an initial
implementation.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
---
 fs/squashfs/Kconfig        |    5 ++
 fs/squashfs/Makefile       |    1 +
 fs/squashfs/decompressor.c |    4 +
 fs/squashfs/lzma_wrapper.c |  151 ++++++++++++++++++++++++++++++++++++++++++++
 fs/squashfs/squashfs.h     |    3 +
 5 files changed, 164 insertions(+), 0 deletions(-)
 create mode 100644 fs/squashfs/lzma_wrapper.c

--- a/fs/squashfs/Kconfig
+++ b/fs/squashfs/Kconfig
@@ -26,6 +26,11 @@ config SQUASHFS
 
 	  If unsure, say N.
 
+config SQUASHFS_LZMA
+	bool "Include support for LZMA compressed file systems"
+	depends on SQUASHFS
+	select DECOMPRESS_LZMA
+
 config SQUASHFS_EMBEDDED
 
 	bool "Additional option for memory-constrained systems" 
--- a/fs/squashfs/Makefile
+++ b/fs/squashfs/Makefile
@@ -5,3 +5,4 @@
 obj-$(CONFIG_SQUASHFS) += squashfs.o
 squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
 squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o
+squashfs-$(CONFIG_SQUASHFS_LZMA) += lzma_wrapper.o
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -50,7 +50,11 @@ static const struct squashfs_decompresso
 
 static const struct squashfs_decompressor *decompressor[] = {
 	&squashfs_zlib_comp_ops,
+#ifdef CONFIG_SQUASHFS_LZMA
+	&squashfs_lzma_comp_ops,
+#else
 	&squashfs_lzma_unsupported_comp_ops,
+#endif
 	&squashfs_lzo_unsupported_comp_ops,
 	&squashfs_unknown_comp_ops
 };
--- /dev/null
+++ b/fs/squashfs/lzma_wrapper.c
@@ -0,0 +1,151 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ * Phillip Lougher <phillip@lougher.demon.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * lzma_wrapper.c
+ */
+
+#include <asm/unaligned.h>
+#include <linux/buffer_head.h>
+#include <linux/mutex.h>
+#include <linux/vmalloc.h>
+#include <linux/decompress/unlzma.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "squashfs.h"
+#include "decompressor.h"
+
+struct squashfs_lzma {
+	void	*input;
+	void	*output;
+};
+
+/* decompress_unlzma.c is currently non re-entrant... */
+DEFINE_MUTEX(lzma_mutex);
+
+/* decompress_unlzma.c doesn't provide any context in its callbacks... */
+static int lzma_error;
+
+static void error(char *m)
+{
+	ERROR("unlzma error: %s\n", m);
+	lzma_error = 1;
+}
+
+	
+static void *lzma_init(struct squashfs_sb_info *msblk)
+{
+	struct squashfs_lzma *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+	if (stream == NULL)
+		goto failed;
+	stream->input = vmalloc(msblk->block_size);
+	if (stream->input == NULL)
+		goto failed;
+	stream->output = vmalloc(msblk->block_size);
+	if (stream->output == NULL)
+		goto failed2;
+
+	return stream;
+
+failed2:
+	vfree(stream->input);
+failed:
+	ERROR("failed to allocate lzma workspace\n");
+	kfree(stream);
+	return NULL;
+}
+
+
+static void lzma_free(void *strm)
+{
+	struct squashfs_lzma *stream = strm;
+
+	if (stream) {
+		vfree(stream->input);
+		vfree(stream->output);
+	}
+	kfree(stream);
+}
+
+
+static int lzma_uncompress(struct squashfs_sb_info *msblk, void **buffer,
+	struct buffer_head **bh, int b, int offset, int length, int srclength,
+	int pages)
+{
+	struct squashfs_lzma *stream = msblk->stream;
+	void *buff = stream->input;
+	int avail, i, bytes = length, res;
+
+	mutex_lock(&lzma_mutex);
+
+	for (i = 0; i < b; i++) {
+		wait_on_buffer(bh[i]);
+		if (!buffer_uptodate(bh[i]))
+			goto block_release;
+
+		avail = min(bytes, msblk->devblksize - offset);
+		memcpy(buff, bh[i]->b_data + offset, avail);
+		buff += avail;
+		bytes -= avail;
+		offset = 0;
+		put_bh(bh[i]);
+	}
+
+	lzma_error = 0;
+	res = unlzma(stream->input, length, NULL, NULL, stream->output, NULL,
+							error);
+	if (res || lzma_error)
+		goto failed;
+
+	/* uncompressed size is stored in the LZMA header (5 byte offset) */
+	res = bytes = get_unaligned_le32(stream->input + 5);
+	for (i = 0, buff = stream->output; bytes && i < pages; i++) {
+		avail = min_t(int, bytes, PAGE_CACHE_SIZE);
+		memcpy(buffer[i], buff, avail);
+		buff += avail;
+		bytes -= avail;
+	}
+	if (bytes)
+		goto failed;
+
+	mutex_unlock(&lzma_mutex);
+	return res;
+
+block_release:
+	for (; i < b; i++)
+		put_bh(bh[i]);
+
+failed:
+	mutex_unlock(&lzma_mutex);
+
+	ERROR("lzma decompression failed, data probably corrupt\n");
+	return -EIO;
+}
+
+const struct squashfs_decompressor squashfs_lzma_comp_ops = {
+	.init = lzma_init,
+	.free = lzma_free,
+	.decompress = lzma_uncompress,
+	.id = LZMA_COMPRESSION,
+	.name = "lzma",
+	.supported = 1
+};
+
--- a/fs/squashfs/squashfs.h
+++ b/fs/squashfs/squashfs.h
@@ -94,3 +94,6 @@ extern const struct address_space_operat
 
 /* zlib_wrapper.c */
 extern const struct squashfs_decompressor squashfs_zlib_comp_ops;
+
+/* lzma wrapper.c */
+extern const struct squashfs_decompressor squashfs_lzma_comp_ops;