From 81bb8debd0d570dc67dc1e9d8b612632cb941893 Mon Sep 17 00:00:00 2001
From: Phillip Lougher <phillip@lougher.demon.co.uk>
Date: Thu, 9 Dec 2010 02:02:29 +0000
Subject: Squashfs: add XZ compression support

Add support for reading file systems compressed with the
XZ compression algorithm.

This patch adds the XZ decompressor wrapper code.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h
index c5137fc..39533fe 100644
--- a/fs/squashfs/squashfs_fs.h
+++ b/fs/squashfs/squashfs_fs.h
@@ -238,6 +238,7 @@ struct meta_index {
 #define ZLIB_COMPRESSION	1
 #define LZMA_COMPRESSION	2
 #define LZO_COMPRESSION		3
+#define XZ_COMPRESSION		4
 
 struct squashfs_super_block {
 	__le32			s_magic;
diff --git a/fs/squashfs/xz_wrapper.c b/fs/squashfs/xz_wrapper.c
new file mode 100644
index 0000000..856756c
--- /dev/null
+++ b/fs/squashfs/xz_wrapper.c
@@ -0,0 +1,153 @@
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ * 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.
+ *
+ * xz_wrapper.c
+ */
+
+
+#include <linux/mutex.h>
+#include <linux/buffer_head.h>
+#include <linux/slab.h>
+#include <linux/xz.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "squashfs.h"
+#include "decompressor.h"
+
+struct squashfs_xz {
+	struct xz_dec *state;
+	struct xz_buf buf;
+};
+
+static void *squashfs_xz_init(struct squashfs_sb_info *msblk)
+{
+	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);
+
+	struct squashfs_xz *stream = kmalloc(sizeof(*stream), GFP_KERNEL);
+	if (stream == NULL)
+		goto failed;
+
+	stream->state = xz_dec_init(XZ_PREALLOC, block_size);
+	if (stream->state == NULL)
+		goto failed;
+
+	return stream;
+
+failed:
+	ERROR("Failed to allocate xz workspace\n");
+	kfree(stream);
+	return NULL;
+}
+
+
+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 **buffer,
+	struct buffer_head **bh, int b, int offset, int length, int srclength,
+	int pages)
+{
+	enum xz_ret xz_err;
+	int avail, total = 0, k = 0, page = 0;
+	struct squashfs_xz *stream = msblk->stream;
+
+	mutex_lock(&msblk->read_data_mutex);
+
+	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_CACHE_SIZE;
+	stream->buf.out = buffer[page++];
+
+	do {
+		if (stream->buf.in_pos == stream->buf.in_size && k < b) {
+			avail = min(length, msblk->devblksize - offset);
+			length -= avail;
+			wait_on_buffer(bh[k]);
+			if (!buffer_uptodate(bh[k]))
+				goto release_mutex;
+
+			if (avail == 0) {
+				offset = 0;
+				put_bh(bh[k++]);
+				continue;
+			}
+
+			stream->buf.in = bh[k]->b_data + offset;
+			stream->buf.in_size = avail;
+			stream->buf.in_pos = 0;
+			offset = 0;
+		}
+
+		if (stream->buf.out_pos == stream->buf.out_size
+							&& page < pages) {
+			stream->buf.out = buffer[page++];
+			stream->buf.out_pos = 0;
+			total += PAGE_CACHE_SIZE;
+		}
+
+		xz_err = xz_dec_run(stream->state, &stream->buf);
+
+		if (stream->buf.in_pos == stream->buf.in_size && k < b)
+			put_bh(bh[k++]);
+	} while (xz_err == XZ_OK);
+
+	if (xz_err != XZ_STREAM_END) {
+		ERROR("xz_dec_run error, data probably corrupt\n");
+		goto release_mutex;
+	}
+
+	if (k < b) {
+		ERROR("xz_uncompress error, input remaining\n");
+		goto release_mutex;
+	}
+
+	total += stream->buf.out_pos;
+	mutex_unlock(&msblk->read_data_mutex);
+	return total;
+
+release_mutex:
+	mutex_unlock(&msblk->read_data_mutex);
+
+	for (; k < b; k++)
+		put_bh(bh[k]);
+
+	return -EIO;
+}
+
+const struct squashfs_decompressor squashfs_xz_comp_ops = {
+	.init = squashfs_xz_init,
+	.free = squashfs_xz_free,
+	.decompress = squashfs_xz_uncompress,
+	.id = XZ_COMPRESSION,
+	.name = "xz",
+	.supported = 1
+};
-- 
cgit v0.10.2


From 7a43ae523744c01b6187013e781f44c2281c579c Mon Sep 17 00:00:00 2001
From: Phillip Lougher <phillip@lougher.demon.co.uk>
Date: Thu, 9 Dec 2010 02:08:31 +0000
Subject: Squashfs: Add XZ compression configuration option

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig
index e5f63da..50cc4ed 100644
--- a/fs/squashfs/Kconfig
+++ b/fs/squashfs/Kconfig
@@ -53,6 +53,21 @@ config SQUASHFS_LZO
 
 	  If unsure, say N.
 
+config SQUASHFS_XZ
+	bool "Include support for XZ compressed file systems"
+	depends on SQUASHFS
+	select XZ_DEC
+	help
+	  Saying Y here includes support for reading Squashfs file systems
+	  compressed with XZ compresssion.  XZ gives better compression than
+	  the default zlib compression, at the expense of greater CPU and
+	  memory overhead.
+
+	  XZ is not the standard compression used in Squashfs and so most
+	  file systems will be readable without selecting this option.
+
+	  If unsure, say N.
+
 config SQUASHFS_EMBEDDED
 	bool "Additional option for memory-constrained systems"
 	depends on SQUASHFS
diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile
index 7672bac..cecf2be 100644
--- a/fs/squashfs/Makefile
+++ b/fs/squashfs/Makefile
@@ -7,3 +7,4 @@ 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-$(CONFIG_SQUASHFS_XATTR) += xattr.o xattr_id.o
 squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o
+squashfs-$(CONFIG_SQUASHFS_XZ) += xz_wrapper.o
diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index 24af9ce..482d781 100644
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -46,6 +46,12 @@ static const struct squashfs_decompressor squashfs_lzo_unsupported_comp_ops = {
 };
 #endif
 
+#ifndef CONFIG_SQUASHFS_XZ
+static const struct squashfs_decompressor squashfs_xz_comp_ops = {
+	NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0
+};
+#endif
+
 static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
 	NULL, NULL, NULL, 0, "unknown", 0
 };
@@ -58,6 +64,7 @@ static const struct squashfs_decompressor *decompressor[] = {
 #else
 	&squashfs_lzo_unsupported_comp_ops,
 #endif
+	&squashfs_xz_comp_ops,
 	&squashfs_unknown_comp_ops
 };
 
diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h
index 7425f80..57e1acb 100644
--- a/fs/squashfs/decompressor.h
+++ b/fs/squashfs/decompressor.h
@@ -52,4 +52,9 @@ static inline int squashfs_decompress(struct squashfs_sb_info *msblk,
 	return msblk->decompressor->decompress(msblk, buffer, bh, b, offset,
 		length, srclength, pages);
 }
+
+#ifdef CONFIG_SQUASHFS_XZ
+extern const struct squashfs_decompressor squashfs_xz_comp_ops;
+#endif
+
 #endif
-- 
cgit v0.10.2


From 170cf02165272dfe026eba183563bad973ca4f05 Mon Sep 17 00:00:00 2001
From: Phillip Lougher <phillip@lougher.demon.co.uk>
Date: Wed, 5 Jan 2011 17:52:26 +0000
Subject: Squashfs: remove unnecessary variable in zlib_wrapper

Get rid of unnecessary bytes variable, and remove redundant
initialisation of zlib_err.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
index 7a60387..1f4833b 100644
--- a/fs/squashfs/zlib_wrapper.c
+++ b/fs/squashfs/zlib_wrapper.c
@@ -66,8 +66,8 @@ static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
 	struct buffer_head **bh, int b, int offset, int length, int srclength,
 	int pages)
 {
-	int zlib_err = 0, zlib_init = 0;
-	int avail, bytes, k = 0, page = 0;
+	int zlib_err, zlib_init = 0;
+	int k = 0, page = 0;
 	z_stream *stream = msblk->stream;
 
 	mutex_lock(&msblk->read_data_mutex);
@@ -75,11 +75,10 @@ static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
 	stream->avail_out = 0;
 	stream->avail_in = 0;
 
-	bytes = length;
 	do {
 		if (stream->avail_in == 0 && k < b) {
-			avail = min(bytes, msblk->devblksize - offset);
-			bytes -= avail;
+			int avail = min(length, msblk->devblksize - offset);
+			length -= avail;
 			wait_on_buffer(bh[k]);
 			if (!buffer_uptodate(bh[k]))
 				goto release_mutex;
-- 
cgit v0.10.2


From e7ee11f0ecd587caed0063c5f68ca20fef699f32 Mon Sep 17 00:00:00 2001
From: Phillip Lougher <phillip@lougher.demon.co.uk>
Date: Wed, 5 Jan 2011 18:02:37 +0000
Subject: Squashfs: add missing check in zlib_wrapper

On file system corruption zlib can return Z_STREAM_OK with
input buffers remaining, which will not be released.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
index 1f4833b..ab5801f 100644
--- a/fs/squashfs/zlib_wrapper.c
+++ b/fs/squashfs/zlib_wrapper.c
@@ -127,6 +127,11 @@ static int zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer,
 		goto release_mutex;
 	}
 
+	if (k < b) {
+		ERROR("zlib_uncompress error, data remaining\n");
+		goto release_mutex;
+	}
+
 	length = stream->total_out;
 	mutex_unlock(&msblk->read_data_mutex);
 	return length;
-- 
cgit v0.10.2


From 6197fd86789a28760f8375b5ae8885cd7258042f Mon Sep 17 00:00:00 2001
From: Phillip Lougher <phillip@lougher.demon.co.uk>
Date: Wed, 5 Jan 2011 18:15:58 +0000
Subject: Squashfs: get rid of default n in Kconfig

As pointed out by Geert Uytterhoeven, "default n" is the default,
no reason to specify it.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig
index 50cc4ed..aa68a8a 100644
--- a/fs/squashfs/Kconfig
+++ b/fs/squashfs/Kconfig
@@ -29,7 +29,6 @@ config SQUASHFS
 config SQUASHFS_XATTR
 	bool "Squashfs XATTR support"
 	depends on SQUASHFS
-	default n
 	help
 	  Saying Y here includes support for extended attributes (xattrs).
 	  Xattrs are name:value pairs associated with inodes by
@@ -40,7 +39,6 @@ config SQUASHFS_XATTR
 config SQUASHFS_LZO
 	bool "Include support for LZO compressed file systems"
 	depends on SQUASHFS
-	default n
 	select LZO_DECOMPRESS
 	help
 	  Saying Y here includes support for reading Squashfs file systems
@@ -71,7 +69,6 @@ config SQUASHFS_XZ
 config SQUASHFS_EMBEDDED
 	bool "Additional option for memory-constrained systems"
 	depends on SQUASHFS
-	default n
 	help
 	  Saying Y here allows you to specify cache size.
 
-- 
cgit v0.10.2


From 8fcd97216f45b1691f8f91f35cc108d06e0bfca8 Mon Sep 17 00:00:00 2001
From: Phillip Lougher <phillip@lougher.demon.co.uk>
Date: Thu, 6 Jan 2011 06:08:50 +0000
Subject: Squashfs: move squashfs_i() definition from squashfs.h

Move squashfs_i() definition out of squashfs.h, this eliminates
the need to #include squashfs_fs_i.h from numerous files.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 653c030..2fb2882 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -34,7 +34,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 #include "decompressor.h"
 
diff --git a/fs/squashfs/cache.c b/fs/squashfs/cache.c
index 57314be..26b15ae 100644
--- a/fs/squashfs/cache.c
+++ b/fs/squashfs/cache.c
@@ -55,7 +55,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 
 /*
diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index 482d781..50b22d3 100644
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -27,7 +27,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "decompressor.h"
 #include "squashfs.h"
 
diff --git a/fs/squashfs/fragment.c b/fs/squashfs/fragment.c
index 7c90bbd..7eef571 100644
--- a/fs/squashfs/fragment.c
+++ b/fs/squashfs/fragment.c
@@ -39,7 +39,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 
 /*
diff --git a/fs/squashfs/id.c b/fs/squashfs/id.c
index b7f64bc..d8f3245 100644
--- a/fs/squashfs/id.c
+++ b/fs/squashfs/id.c
@@ -37,7 +37,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 
 /*
diff --git a/fs/squashfs/lzo_wrapper.c b/fs/squashfs/lzo_wrapper.c
index 5d87789..7da759e 100644
--- a/fs/squashfs/lzo_wrapper.c
+++ b/fs/squashfs/lzo_wrapper.c
@@ -29,7 +29,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 #include "decompressor.h"
 
diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h
index 5d45569..18f187f 100644
--- a/fs/squashfs/squashfs.h
+++ b/fs/squashfs/squashfs.h
@@ -27,11 +27,6 @@
 
 #define WARNING(s, args...)	pr_warning("SQUASHFS: "s, ## args)
 
-static inline struct squashfs_inode_info *squashfs_i(struct inode *inode)
-{
-	return list_entry(inode, struct squashfs_inode_info, vfs_inode);
-}
-
 /* block.c */
 extern int squashfs_read_data(struct super_block *, void **, u64, int, u64 *,
 				int, int);
diff --git a/fs/squashfs/squashfs_fs_i.h b/fs/squashfs/squashfs_fs_i.h
index d3e3a37..359baef 100644
--- a/fs/squashfs/squashfs_fs_i.h
+++ b/fs/squashfs/squashfs_fs_i.h
@@ -45,4 +45,10 @@ struct squashfs_inode_info {
 	};
 	struct inode	vfs_inode;
 };
+
+
+static inline struct squashfs_inode_info *squashfs_i(struct inode *inode)
+{
+	return list_entry(inode, struct squashfs_inode_info, vfs_inode);
+}
 #endif
diff --git a/fs/squashfs/xattr_id.c b/fs/squashfs/xattr_id.c
index d33be5d..05385db 100644
--- a/fs/squashfs/xattr_id.c
+++ b/fs/squashfs/xattr_id.c
@@ -32,7 +32,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 #include "xattr.h"
 
diff --git a/fs/squashfs/zlib_wrapper.c b/fs/squashfs/zlib_wrapper.c
index ab5801f..818a5e0 100644
--- a/fs/squashfs/zlib_wrapper.c
+++ b/fs/squashfs/zlib_wrapper.c
@@ -29,7 +29,6 @@
 
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
-#include "squashfs_fs_i.h"
 #include "squashfs.h"
 #include "decompressor.h"
 
-- 
cgit v0.10.2


From 01a678c5a2f41663b8faf03d17e2bbdbf44158a9 Mon Sep 17 00:00:00 2001
From: Phillip Lougher <phillip@lougher.demon.co.uk>
Date: Wed, 5 Jan 2011 18:23:53 +0000
Subject: Squashfs: simplify CONFIG_SQUASHFS_LZO handling

Get rid of messy repeated #if(n)def CONFIG_SQUASHFS_LZO code
in decompressor.c

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index 50b22d3..a5940e5 100644
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -40,7 +40,7 @@ static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = {
 };
 
 #ifndef CONFIG_SQUASHFS_LZO
-static const struct squashfs_decompressor squashfs_lzo_unsupported_comp_ops = {
+static const struct squashfs_decompressor squashfs_lzo_comp_ops = {
 	NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0
 };
 #endif
@@ -57,13 +57,9 @@ static const struct squashfs_decompressor squashfs_unknown_comp_ops = {
 
 static const struct squashfs_decompressor *decompressor[] = {
 	&squashfs_zlib_comp_ops,
-	&squashfs_lzma_unsupported_comp_ops,
-#ifdef CONFIG_SQUASHFS_LZO
 	&squashfs_lzo_comp_ops,
-#else
-	&squashfs_lzo_unsupported_comp_ops,
-#endif
 	&squashfs_xz_comp_ops,
+	&squashfs_lzma_unsupported_comp_ops,
 	&squashfs_unknown_comp_ops
 };
 
diff --git a/fs/squashfs/decompressor.h b/fs/squashfs/decompressor.h
index 57e1acb..3b305a7 100644
--- a/fs/squashfs/decompressor.h
+++ b/fs/squashfs/decompressor.h
@@ -57,4 +57,8 @@ static inline int squashfs_decompress(struct squashfs_sb_info *msblk,
 extern const struct squashfs_decompressor squashfs_xz_comp_ops;
 #endif
 
+#ifdef CONFIG_SQUASHFS_LZO
+extern const struct squashfs_decompressor squashfs_lzo_comp_ops;
+#endif
+
 #endif
diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h
index 18f187f..ba729d8 100644
--- a/fs/squashfs/squashfs.h
+++ b/fs/squashfs/squashfs.h
@@ -99,6 +99,3 @@ extern const struct xattr_handler *squashfs_xattr_handlers[];
 
 /* zlib_wrapper.c */
 extern const struct squashfs_decompressor squashfs_zlib_comp_ops;
-
-/* lzo_wrapper.c */
-extern const struct squashfs_decompressor squashfs_lzo_comp_ops;
-- 
cgit v0.10.2