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

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright (C) 2001-2003 Red Hat, Inc.
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 * $Id: compr_zlib.c,v 1.29 2004/11/16 20:36:11 dwmw2 Exp $
 *
 */

#if !defined(__KERNEL__) && !defined(__ECOS)
#error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
#endif

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/zlib.h>
#include <linux/zutil.h>
#include <asm/semaphore.h>
#include "nodelist.h"
#include "compr.h"

	/* Plan: call deflate() with avail_in == *sourcelen, 
		avail_out = *dstlen - 12 and flush == Z_FINISH. 
		If it doesn't manage to finish,	call it again with
		avail_in == 0 and avail_out set to the remaining 12
		bytes for it to clean up. 
	   Q: Is 12 bytes sufficient?
	*/
#define STREAM_END_SPACE 12

static DECLARE_MUTEX(deflate_sem);
static DECLARE_MUTEX(inflate_sem);
static z_stream inf_strm, def_strm;

#ifdef __KERNEL__ /* Linux-only */
#include <linux/vmalloc.h>
#include <linux/init.h>

static int __init alloc_workspaces(void)
{
	def_strm.workspace = vmalloc(zlib_deflate_workspacesize());
	if (!def_strm.workspace) {
		printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize());
		return -ENOMEM;
	}
	D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize()));
	inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
	if (!inf_strm.workspace) {
		printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize());
		vfree(def_strm.workspace);
		return -ENOMEM;
	}
	D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize()));
	return 0;
}

static void free_workspaces(void)
{
	vfree(def_strm.workspace);
	vfree(inf_strm.workspace);
}
#else
#define alloc_workspaces() (0)
#define free_workspaces() do { } while(0)
#endif /* __KERNEL__ */

static int jffs2_zlib_compress(unsigned char *data_in,
			       unsigned char *cpage_out,
			       uint32_t *sourcelen, uint32_t *dstlen,
			       void *model)
{
	int ret;

	if (*dstlen <= STREAM_END_SPACE)
		return -1;

	down(&deflate_sem);

	if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
		printk(KERN_WARNING "deflateInit failed\n");
		up(&deflate_sem);
		return -1;
	}

	def_strm.next_in = data_in;
	def_strm.total_in = 0;
	
	def_strm.next_out = cpage_out;
	def_strm.total_out = 0;

	while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) {
		def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE);
		def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out);
		D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n",
			  def_strm.avail_in, def_strm.avail_out));
		ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH);
		D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", 
			  def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out));
		if (ret != Z_OK) {
			D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret));
			zlib_deflateEnd(&def_strm);
			up(&deflate_sem);
			return -1;
		}
	}
	def_strm.avail_out += STREAM_END_SPACE;
	def_strm.avail_in = 0;
	ret = zlib_deflate(&def_strm, Z_FINISH);
	zlib_deflateEnd(&def_strm);

	if (ret != Z_STREAM_END) {
		D1(printk(KERN_DEBUG "final deflate returned %d\n", ret));
		ret = -1;
		goto out;
	}

	if (def_strm.total_out >= def_strm.total_in) {
		D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n",
			  def_strm.total_in, def_strm.total_out));
		ret = -1;
		goto out;
	}

	D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n",
		  def_strm.total_in, def_strm.total_out));

	*dstlen = def_strm.total_out;
	*sourcelen = def_strm.total_in;
	ret = 0;
 out:
	up(&deflate_sem);
	return ret;
}

static int jffs2_zlib_decompress(unsigned char *data_in,
				 unsigned char *cpage_out,
				 uint32_t srclen, uint32_t destlen,
				 void *model)
{
	int ret;
	int wbits = MAX_WBITS;

	down(&inflate_sem);

	inf_strm.next_in = data_in;
	inf_strm.avail_in = srclen;
	inf_strm.total_in = 0;
	
	inf_strm.next_out = cpage_out;
	inf_strm.avail_out = destlen;
	inf_strm.total_out = 0;

	/* If it's deflate, and it's got no preset dictionary, then
	   we can tell zlib to skip the adler32 check. */
	if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
	    ((data_in[0] & 0x0f) == Z_DEFLATED) &&
	    !(((data_in[0]<<8) + data_in[1]) % 31)) {

		D2(printk(KERN_DEBUG "inflate skipping adler32\n"));
		wbits = -((data_in[0] >> 4) + 8);
		inf_strm.next_in += 2;
		inf_strm.avail_in -= 2;
	} else {
		/* Let this remain D1 for now -- it should never happen */
		D1(printk(KERN_DEBUG "inflate not skipping adler32\n"));
	}


	if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
		printk(KERN_WARNING "inflateInit failed\n");
		up(&inflate_sem);
		return 1;
	}

	while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
		;
	if (ret != Z_STREAM_END) {
		printk(KERN_NOTICE "inflate returned %d\n", ret);
	}
	zlib_inflateEnd(&inf_strm);
	up(&inflate_sem);
        return 0;
}

static struct jffs2_compressor jffs2_zlib_comp = {
    .priority = JFFS2_ZLIB_PRIORITY,
    .name = "zlib",
    .compr = JFFS2_COMPR_ZLIB,
    .compress = &jffs2_zlib_compress,
    .decompress = &jffs2_zlib_decompress,
#ifdef JFFS2_ZLIB_DISABLED
    .disabled = 1,
#else
    .disabled = 0,
#endif
};

int __init jffs2_zlib_init(void)
{
    int ret;

    ret = alloc_workspaces();
    if (ret)
        return ret;

    ret = jffs2_register_compressor(&jffs2_zlib_comp);
    if (ret)
        free_workspaces();

    return ret;
}

void jffs2_zlib_exit(void)
{
    jffs2_unregister_compressor(&jffs2_zlib_comp);
    free_workspaces();
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* JFFS2 -- Journalling Flash File System, Version 2.
	3	*
	4	* Copyright (C) 2001-2003 Red Hat, Inc.
	5	*
	6	* Created by David Woodhouse <dwmw2@infradead.org>
	7	*
	8	* For licensing information, see the file 'LICENCE' in this directory.
	9	*
	10	* $Id: compr_zlib.c,v 1.29 2004/11/16 20:36:11 dwmw2 Exp $
	11	*
	12	*/
	13
	14	#if !defined(__KERNEL__) && !defined(__ECOS)
	15	#error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
	16	#endif
	17
	18	#include <linux/config.h>
	19	#include <linux/kernel.h>
	20	#include <linux/slab.h>
	21	#include <linux/zlib.h>
	22	#include <linux/zutil.h>
	23	#include <asm/semaphore.h>
	24	#include "nodelist.h"
	25	#include "compr.h"
	26
	27	/* Plan: call deflate() with avail_in == *sourcelen,
	28	avail_out = *dstlen - 12 and flush == Z_FINISH.
	29	If it doesn't manage to finish, call it again with
	30	avail_in == 0 and avail_out set to the remaining 12
	31	bytes for it to clean up.
	32	Q: Is 12 bytes sufficient?
	33	*/
	34	#define STREAM_END_SPACE 12
	35
	36	static DECLARE_MUTEX(deflate_sem);
	37	static DECLARE_MUTEX(inflate_sem);
	38	static z_stream inf_strm, def_strm;
	39
	40	#ifdef __KERNEL__ /* Linux-only */
	41	#include <linux/vmalloc.h>
	42	#include <linux/init.h>
	43
	44	static int __init alloc_workspaces(void)
	45	{
	46	def_strm.workspace = vmalloc(zlib_deflate_workspacesize());
	47	if (!def_strm.workspace) {
	48	printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize());
	49	return -ENOMEM;
	50	}
	51	D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize()));
	52	inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
	53	if (!inf_strm.workspace) {
	54	printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize());
	55	vfree(def_strm.workspace);
	56	return -ENOMEM;
	57	}
	58	D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize()));
	59	return 0;
	60	}
	61
	62	static void free_workspaces(void)
	63	{
	64	vfree(def_strm.workspace);
65	vfree(inf_strm.workspace);
66	}
67	#else
68	#define alloc_workspaces() (0)
69	#define free_workspaces() do { } while(0)
70	#endif /* __KERNEL__ */
71
75c96f85 AB	72	static int jffs2_zlib_compress(unsigned char *data_in,
	73	unsigned char *cpage_out,
	74	uint32_t sourcelen, uint32_t dstlen,
	75	void *model)
1da177e4 LT	76	{
	77	int ret;
	78
	79	if (*dstlen <= STREAM_END_SPACE)
	80	return -1;
	81
	82	down(&deflate_sem);
	83
	84	if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
	85	printk(KERN_WARNING "deflateInit failed\n");
	86	up(&deflate_sem);
	87	return -1;
	88	}
	89
	90	def_strm.next_in = data_in;
	91	def_strm.total_in = 0;
	92
	93	def_strm.next_out = cpage_out;
	94	def_strm.total_out = 0;
	95
	96	while (def_strm.total_out < dstlen - STREAM_END_SPACE && def_strm.total_in < sourcelen) {
	97	def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE);
	98	def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out);
	99	D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n",
	100	def_strm.avail_in, def_strm.avail_out));
	101	ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH);
	102	D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n",
	103	def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out));
	104	if (ret != Z_OK) {
	105	D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret));
	106	zlib_deflateEnd(&def_strm);
	107	up(&deflate_sem);
	108	return -1;
	109	}
	110	}
	111	def_strm.avail_out += STREAM_END_SPACE;
	112	def_strm.avail_in = 0;
	113	ret = zlib_deflate(&def_strm, Z_FINISH);
	114	zlib_deflateEnd(&def_strm);
	115
	116	if (ret != Z_STREAM_END) {
	117	D1(printk(KERN_DEBUG "final deflate returned %d\n", ret));
	118	ret = -1;
	119	goto out;
	120	}
	121
	122	if (def_strm.total_out >= def_strm.total_in) {
	123	D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n",
	124	def_strm.total_in, def_strm.total_out));
	125	ret = -1;
	126	goto out;
	127	}
	128
	129	D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n",
	130	def_strm.total_in, def_strm.total_out));
	131
	132	*dstlen = def_strm.total_out;
	133	*sourcelen = def_strm.total_in;
	134	ret = 0;
	135	out:
	136	up(&deflate_sem);
	137	return ret;
	138	}
	139
75c96f85 AB	140	static int jffs2_zlib_decompress(unsigned char *data_in,
	141	unsigned char *cpage_out,
	142	uint32_t srclen, uint32_t destlen,
	143	void *model)
1da177e4 LT	144	{
	145	int ret;
	146	int wbits = MAX_WBITS;
	147
	148	down(&inflate_sem);
	149
	150	inf_strm.next_in = data_in;
	151	inf_strm.avail_in = srclen;
	152	inf_strm.total_in = 0;
	153
	154	inf_strm.next_out = cpage_out;
	155	inf_strm.avail_out = destlen;
	156	inf_strm.total_out = 0;
	157
	158	/* If it's deflate, and it's got no preset dictionary, then
	159	we can tell zlib to skip the adler32 check. */
	160	if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
	161	((data_in[0] & 0x0f) == Z_DEFLATED) &&
	162	!(((data_in[0]<<8) + data_in[1]) % 31)) {
	163
	164	D2(printk(KERN_DEBUG "inflate skipping adler32\n"));
	165	wbits = -((data_in[0] >> 4) + 8);
	166	inf_strm.next_in += 2;
	167	inf_strm.avail_in -= 2;
	168	} else {
	169	/* Let this remain D1 for now -- it should never happen */
	170	D1(printk(KERN_DEBUG "inflate not skipping adler32\n"));
	171	}
	172
	173
	174	if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
	175	printk(KERN_WARNING "inflateInit failed\n");
	176	up(&inflate_sem);
	177	return 1;
	178	}
	179
	180	while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
	181	;
	182	if (ret != Z_STREAM_END) {
	183	printk(KERN_NOTICE "inflate returned %d\n", ret);
	184	}
	185	zlib_inflateEnd(&inf_strm);
	186	up(&inflate_sem);
	187	return 0;
	188	}
	189
	190	static struct jffs2_compressor jffs2_zlib_comp = {
	191	.priority = JFFS2_ZLIB_PRIORITY,
	192	.name = "zlib",
	193	.compr = JFFS2_COMPR_ZLIB,
	194	.compress = &jffs2_zlib_compress,
	195	.decompress = &jffs2_zlib_decompress,
	196	#ifdef JFFS2_ZLIB_DISABLED
	197	.disabled = 1,
	198	#else
	199	.disabled = 0,
	200	#endif
	201	};
	202
	203	int __init jffs2_zlib_init(void)
	204	{
	205	int ret;
	206
	207	ret = alloc_workspaces();
208	if (ret)
209	return ret;
210
211	ret = jffs2_register_compressor(&jffs2_zlib_comp);
212	if (ret)
213	free_workspaces();
214
215	return ret;
216	}
217
218	void jffs2_zlib_exit(void)
219	{
220	jffs2_unregister_compressor(&jffs2_zlib_comp);
221	free_workspaces();
222	}