Commit 79cb8ced authored by Chan Jeong's avatar Chan Jeong Committed by Phillip Lougher
Browse files

Squashfs: Add LZO compression support 



Signed-off-by: default avatarChan Jeong <chan.jeong@lge.com>
Signed-off-by: default avatarPhillip Lougher <phillip@lougher.demon.co.uk>
parent 4690148f

fs/squashfs/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -37,6 +37,11 @@ config SQUASHFS_XATTR 


	  If unsure, say N.



config SQUASHFS_LZO

	bool "Include support for LZO compressed file systems"

	depends on SQUASHFS

	select LZO_DECOMPRESS



config SQUASHFS_EMBEDDED



	bool "Additional option for memory-constrained systems"

fs/squashfs/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -6,4 +6,4 @@ 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_XATTR) += xattr.o xattr_id.o

squashfs-$(CONFIG_SQUASHFS_LZO) += lzo_wrapper.o

fs/squashfs/decompressor.c

+6 −0
Original line number Diff line number Diff line
@@ -40,9 +40,11 @@ static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = { 
	NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0

};



#ifndef CONFIG_SQUASHFS_LZO

static const struct squashfs_decompressor squashfs_lzo_unsupported_comp_ops = {

	NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0

};

#endif



static const struct squashfs_decompressor squashfs_unknown_comp_ops = {

	NULL, NULL, NULL, 0, "unknown", 0
@@ -51,7 +53,11 @@ 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_unknown_comp_ops

};

fs/squashfs/lzo_wrapper.c

0 → 100644
+134 −0
Original line number Diff line number Diff line 
/*

 * Squashfs - a compressed read only filesystem for Linux

 *

 * Copyright (c) 2010 LG Electronics

 * Chan Jeong <chan.jeong@lge.com>

 *

 * 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.

 *

 * lzo_wrapper.c

 */



#include <linux/mutex.h>

#include <linux/buffer_head.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>

#include <linux/lzo.h>



#include "squashfs_fs.h"

#include "squashfs_fs_sb.h"

#include "squashfs_fs_i.h"

#include "squashfs.h"

#include "decompressor.h"



struct squashfs_lzo {

	void	*input;

	void	*output;

};



static void *lzo_init(struct squashfs_sb_info *msblk)

{

	struct squashfs_lzo *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 lzo workspace\n");

	kfree(stream);

	return NULL;

}





static void lzo_free(void *strm)

{

	struct squashfs_lzo *stream = strm;



	if (stream) {

		vfree(stream->input);

		vfree(stream->output);

	}

	kfree(stream);

}





static int lzo_uncompress(struct squashfs_sb_info *msblk, void **buffer,

	struct buffer_head **bh, int b, int offset, int length, int srclength,

	int pages)

{

	struct squashfs_lzo *stream = msblk->stream;

	void *buff = stream->input;

	int avail, i, bytes = length, res;

	size_t out_len = msblk->block_size;



	mutex_lock(&msblk->read_data_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]);

	}



	res = lzo1x_decompress_safe(stream->input, (size_t)length,

					stream->output, &out_len);

	if (res != LZO_E_OK)

		goto failed;



	res = bytes = (int)out_len;

	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;

	}



	mutex_unlock(&msblk->read_data_mutex);

	return res;



block_release:

	for (; i < b; i++)

		put_bh(bh[i]);



failed:

	mutex_unlock(&msblk->read_data_mutex);



	ERROR("lzo decompression failed, data probably corrupt\n");

	return -EIO;

}



const struct squashfs_decompressor squashfs_lzo_comp_ops = {

	.init = lzo_init,

	.free = lzo_free,

	.decompress = lzo_uncompress,

	.id = LZO_COMPRESSION,

	.name = "lzo",

	.supported = 1

};

fs/squashfs/squashfs.h

+3 −0
Original line number Diff line number Diff line
@@ -104,3 +104,6 @@ extern const struct xattr_handler *squashfs_xattr_handlers[]; 


/* zlib_wrapper.c */

extern const struct squashfs_decompressor squashfs_zlib_comp_ops;



/* lzo_wrappers.c */

extern const struct squashfs_decompressor squashfs_lzo_comp_ops;