fs/squashfs/lzo_wrapper.c

/*
 * 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.h"
#include "decompressor.h"
#include "page_actor.h"

struct squashfs_lzo {
	void	*input;
	void	*output;
};

static void *lzo_init(struct squashfs_sb_info *msblk, void *buff)
{
	int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE);

	struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
	if (stream == NULL)
		goto failed;
	stream->input = vmalloc(block_size);
	if (stream->input == NULL)
		goto failed;
	stream->output = vmalloc(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 ERR_PTR(-ENOMEM);
}


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 *strm,
	struct buffer_head **bh, int b, int offset, int length,
	struct squashfs_page_actor *output)
{
	int res;
	size_t out_len = output->length;
	struct squashfs_lzo *stream = strm;

	squashfs_bh_to_buf(bh, b, stream->input, offset, length,
		msblk->devblksize);
	res = lzo1x_decompress_safe(stream->input, (size_t)length,
					stream->output, &out_len);
	if (res != LZO_E_OK)
		return -EIO;
	squashfs_buf_to_actor(stream->output, output, out_len);

	return out_len;
}

const struct squashfs_decompressor squashfs_lzo_comp_ops = {
	.init = lzo_init,
	.free = lzo_free,
	.decompress = lzo_uncompress,
	.id = LZO_COMPRESSION,
	.name = "lzo",
	.supported = 1
};