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

Squashfs: Add LZO compression support

parent 4690148f
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+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" 
+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
+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
};

+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
};
+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;