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Commit c799aca3 authored by Richard Purdie's avatar Richard Purdie Committed by David Woodhouse
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[JFFS2] Add LZO compression support. 



Add LZO1X compression/decompression support to jffs2.

LZO's interface doesn't entirely match that required by jffs2 so a
buffer and memcpy is unavoidable.

Signed-off-by: default avatarRichard Purdie <rpurdie@openedhand.com>
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
parent 8691a729

fs/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -1314,6 +1314,17 @@ config JFFS2_ZLIB 


	  Say 'Y' if unsure.



config JFFS2_LZO

	bool "JFFS2 LZO compression support" if JFFS2_COMPRESSION_OPTIONS

	select LZO_COMPRESS

	select LZO_DECOMPRESS

	depends on JFFS2_FS

	default y

	help

	  minilzo-based compression. Generally works better than Zlib.



	  Say 'Y' if unsure.



config JFFS2_RTIME

	bool "JFFS2 RTIME compression support" if JFFS2_COMPRESSION_OPTIONS

	depends on JFFS2_FS

fs/jffs2/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -17,4 +17,5 @@ jffs2-$(CONFIG_JFFS2_FS_POSIX_ACL) += acl.o 
jffs2-$(CONFIG_JFFS2_RUBIN)	+= compr_rubin.o

jffs2-$(CONFIG_JFFS2_RTIME)	+= compr_rtime.o

jffs2-$(CONFIG_JFFS2_ZLIB)	+= compr_zlib.o

jffs2-$(CONFIG_JFFS2_LZO)	+= compr_lzo.o

jffs2-$(CONFIG_JFFS2_SUMMARY)   += summary.o

fs/jffs2/compr.c

+6 −0
Original line number Diff line number Diff line
@@ -286,6 +286,9 @@ int __init jffs2_compressors_init(void) 
	jffs2_rubinmips_init();

	jffs2_dynrubin_init();

#endif

#ifdef CONFIG_JFFS2_LZO

	jffs2_lzo_init();

#endif

/* Setting default compression mode */

#ifdef CONFIG_JFFS2_CMODE_NONE

	jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
@@ -304,6 +307,9 @@ int __init jffs2_compressors_init(void) 
int jffs2_compressors_exit(void)

{

/* Unregistering compressors */

#ifdef CONFIG_JFFS2_LZO

	jffs2_lzo_exit();

#endif

#ifdef CONFIG_JFFS2_RUBIN

	jffs2_dynrubin_exit();

	jffs2_rubinmips_exit();

fs/jffs2/compr.h

+2 −1
Original line number Diff line number Diff line
@@ -27,9 +27,10 @@ 
#define JFFS2_RUBINMIPS_PRIORITY 10

#define JFFS2_DYNRUBIN_PRIORITY  20

#define JFFS2_LZARI_PRIORITY     30

#define JFFS2_LZO_PRIORITY       40

#define JFFS2_RTIME_PRIORITY     50

#define JFFS2_ZLIB_PRIORITY      60

#define JFFS2_LZO_PRIORITY       80





#define JFFS2_RUBINMIPS_DISABLED /* RUBINs will be used only */

#define JFFS2_DYNRUBIN_DISABLED  /*	   for decompression */

fs/jffs2/compr_lzo.c

0 → 100644
+108 −0
Original line number Diff line number Diff line 
/*

 * JFFS2 -- Journalling Flash File System, Version 2.

 *

 * Copyright © 2007 Nokia Corporation. All rights reserved.

 *

 * 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/slab.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);



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);

	mutex_unlock(&deflate_mutex);



	if (ret != LZO_E_OK)

		return -1;



	if (compress_size > *dstlen)

		return -1;



	memcpy(cpage_out, lzo_compress_buf, compress_size);

	*dstlen = compress_size;



	return 0;

}



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();

}