[net-next-2.6.git] / fs / jffs2 / compr_lzo.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2007 Nokia Corporation. All rights reserved.
 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
 *
 * Created by Richard Purdie <rpurdie@openedhand.com>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/lzo.h>
#include "compr.h"

static void *lzo_mem;
static void *lzo_compress_buf;
static DEFINE_MUTEX(deflate_mutex);	/* for lzo_mem and lzo_compress_buf */

static void free_workspace(void)
{
	vfree(lzo_mem);
	vfree(lzo_compress_buf);
}

static int __init alloc_workspace(void)
{
	lzo_mem = vmalloc(LZO1X_MEM_COMPRESS);
	lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));

	if (!lzo_mem || !lzo_compress_buf) {
		printk(KERN_WARNING "Failed to allocate lzo deflate workspace\n");
		free_workspace();
		return -ENOMEM;
	}

	return 0;
}

static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out,
			      uint32_t *sourcelen, uint32_t *dstlen, void *model)
{
	size_t compress_size;
	int ret;

	mutex_lock(&deflate_mutex);
	ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
	if (ret != LZO_E_OK)
		goto fail;

	if (compress_size > *dstlen)
		goto fail;

	memcpy(cpage_out, lzo_compress_buf, compress_size);
	mutex_unlock(&deflate_mutex);

	*dstlen = compress_size;
	return 0;

 fail:
	mutex_unlock(&deflate_mutex);
	return -1;
}

static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out,
				 uint32_t srclen, uint32_t destlen, void *model)
{
	size_t dl = destlen;
	int ret;

	ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);

	if (ret != LZO_E_OK || dl != destlen)
		return -1;

	return 0;
}

static struct jffs2_compressor jffs2_lzo_comp = {
	.priority = JFFS2_LZO_PRIORITY,
	.name = "lzo",
	.compr = JFFS2_COMPR_LZO,
	.compress = &jffs2_lzo_compress,
	.decompress = &jffs2_lzo_decompress,
	.disabled = 0,
};

int __init jffs2_lzo_init(void)
{
	int ret;

	ret = alloc_workspace();
	if (ret < 0)
		return ret;

	ret = jffs2_register_compressor(&jffs2_lzo_comp);
	if (ret)
		free_workspace();

	return ret;
}

void jffs2_lzo_exit(void)
{
	jffs2_unregister_compressor(&jffs2_lzo_comp);
	free_workspace();
}
Commit	Line	Data
c799aca3 RP	1	/*
	2	* JFFS2 -- Journalling Flash File System, Version 2.
	3	*
	4	* Copyright © 2007 Nokia Corporation. All rights reserved.
6088c058	5	* Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
c799aca3 RP	6	*
	7	* Created by Richard Purdie <rpurdie@openedhand.com>
	8	*
	9	* For licensing information, see the file 'LICENCE' in this directory.
	10	*
	11	*/
	12
	13	#include <linux/kernel.h>
	14	#include <linux/sched.h>
c799aca3 RP	15	#include <linux/vmalloc.h>
	16	#include <linux/init.h>
	17	#include <linux/lzo.h>
	18	#include "compr.h"
	19
	20	static void *lzo_mem;
	21	static void *lzo_compress_buf;
dc8a0843	22	static DEFINE_MUTEX(deflate_mutex); /* for lzo_mem and lzo_compress_buf */
c799aca3 RP	23
	24	static void free_workspace(void)
	25	{
	26	vfree(lzo_mem);
	27	vfree(lzo_compress_buf);
	28	}
	29
	30	static int __init alloc_workspace(void)
	31	{
	32	lzo_mem = vmalloc(LZO1X_MEM_COMPRESS);
	33	lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));
	34
	35	if (!lzo_mem \|\| !lzo_compress_buf) {
	36	printk(KERN_WARNING "Failed to allocate lzo deflate workspace\n");
	37	free_workspace();
	38	return -ENOMEM;
	39	}
	40
	41	return 0;
	42	}
	43
	44	static int jffs2_lzo_compress(unsigned char data_in, unsigned char cpage_out,
	45	uint32_t sourcelen, uint32_t dstlen, void *model)
	46	{
	47	size_t compress_size;
	48	int ret;
	49
	50	mutex_lock(&deflate_mutex);
	51	ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
c799aca3	52	if (ret != LZO_E_OK)
dc8a0843	53	goto fail;
c799aca3 RP	54
c799aca3 RP	55	if (compress_size > *dstlen)
dc8a0843	56	goto fail;
c799aca3 RP	57
c799aca3 RP	58	memcpy(cpage_out, lzo_compress_buf, compress_size);
dc8a0843	59	mutex_unlock(&deflate_mutex);
c799aca3	60
dc8a0843	61	*dstlen = compress_size;
c799aca3	62	return 0;
dc8a0843 GU	63
	64	fail:
	65	mutex_unlock(&deflate_mutex);
	66	return -1;
c799aca3 RP	67	}
	68
	69	static int jffs2_lzo_decompress(unsigned char data_in, unsigned char cpage_out,
	70	uint32_t srclen, uint32_t destlen, void *model)
	71	{
	72	size_t dl = destlen;
	73	int ret;
	74
	75	ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);
	76
	77	if (ret != LZO_E_OK \|\| dl != destlen)
	78	return -1;
	79
	80	return 0;
	81	}
	82
	83	static struct jffs2_compressor jffs2_lzo_comp = {
	84	.priority = JFFS2_LZO_PRIORITY,
	85	.name = "lzo",
	86	.compr = JFFS2_COMPR_LZO,
	87	.compress = &jffs2_lzo_compress,
	88	.decompress = &jffs2_lzo_decompress,
	89	.disabled = 0,
	90	};
	91
	92	int __init jffs2_lzo_init(void)
	93	{
	94	int ret;
	95
	96	ret = alloc_workspace();
	97	if (ret < 0)
	98	return ret;
	99
	100	ret = jffs2_register_compressor(&jffs2_lzo_comp);
	101	if (ret)
	102	free_workspace();
	103
	104	return ret;
	105	}
	106
	107	void jffs2_lzo_exit(void)
	108	{
	109	jffs2_unregister_compressor(&jffs2_lzo_comp);
	110	free_workspace();
	111	}