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

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
 *
 * Created by David Woodhouse <dwmw2@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

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

#include <linux/kernel.h>
#include <linux/zlib.h>
#include <linux/zutil.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 DEFINE_MUTEX(deflate_mutex);
static DEFINE_MUTEX(inflate_mutex);
static z_stream inf_strm, def_strm;

#ifdef __KERNEL__ /* Linux-only */
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/mutex.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)
{
	int ret;

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

	mutex_lock(&deflate_mutex);

	if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
		printk(KERN_WARNING "deflateInit failed\n");
		mutex_unlock(&deflate_mutex);
		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);
			mutex_unlock(&deflate_mutex);
			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:
	mutex_unlock(&deflate_mutex);
	return ret;
}

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

	mutex_lock(&inflate_mutex);

	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");
		mutex_unlock(&inflate_mutex);
		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);
	mutex_unlock(&inflate_mutex);
	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	*
c00c310e	4	* Copyright © 2001-2007 Red Hat, Inc.
6088c058	5	* Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
1da177e4 LT	6	*
	7	* Created by David Woodhouse <dwmw2@infradead.org>
	8	*
	9	* For licensing information, see the file 'LICENCE' in this directory.
	10	*
1da177e4 LT	11	*/
	12
	13	#if !defined(__KERNEL__) && !defined(__ECOS)
	14	#error "The userspace support got too messy and was removed. Update your mkfs.jffs2"
	15	#endif
	16
1da177e4	17	#include <linux/kernel.h>
1da177e4 LT	18	#include <linux/zlib.h>
1da177e4 LT	19	#include <linux/zutil.h>
1da177e4 LT	20	#include "nodelist.h"
	21	#include "compr.h"
	22
182ec4ee TG	23	/* Plan: call deflate() with avail_in == *sourcelen,
182ec4ee TG	24	avail_out = *dstlen - 12 and flush == Z_FINISH.
1da177e4 LT	25	If it doesn't manage to finish, call it again with
1da177e4 LT	26	avail_in == 0 and avail_out set to the remaining 12
182ec4ee	27	bytes for it to clean up.
1da177e4 LT	28	Q: Is 12 bytes sufficient?
	29	*/
	30	#define STREAM_END_SPACE 12
	31
353ab6e9 IM	32	static DEFINE_MUTEX(deflate_mutex);
353ab6e9 IM	33	static DEFINE_MUTEX(inflate_mutex);
1da177e4 LT	34	static z_stream inf_strm, def_strm;
	35
	36	#ifdef __KERNEL__ /* Linux-only */
	37	#include <linux/vmalloc.h>
	38	#include <linux/init.h>
353ab6e9	39	#include <linux/mutex.h>
1da177e4 LT	40
	41	static int __init alloc_workspaces(void)
	42	{
	43	def_strm.workspace = vmalloc(zlib_deflate_workspacesize());
	44	if (!def_strm.workspace) {
	45	printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize());
	46	return -ENOMEM;
	47	}
	48	D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize()));
	49	inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
	50	if (!inf_strm.workspace) {
	51	printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize());
	52	vfree(def_strm.workspace);
	53	return -ENOMEM;
	54	}
	55	D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize()));
	56	return 0;
	57	}
	58
	59	static void free_workspaces(void)
	60	{
	61	vfree(def_strm.workspace);
	62	vfree(inf_strm.workspace);
	63	}
	64	#else
	65	#define alloc_workspaces() (0)
	66	#define free_workspaces() do { } while(0)
	67	#endif /* __KERNEL__ */
	68
75c96f85 AB	69	static int jffs2_zlib_compress(unsigned char *data_in,
75c96f85 AB	70	unsigned char *cpage_out,
088bd455	71	uint32_t sourcelen, uint32_t dstlen)
1da177e4 LT	72	{
	73	int ret;
	74
	75	if (*dstlen <= STREAM_END_SPACE)
	76	return -1;
	77
353ab6e9	78	mutex_lock(&deflate_mutex);
1da177e4 LT	79
	80	if (Z_OK != zlib_deflateInit(&def_strm, 3)) {
	81	printk(KERN_WARNING "deflateInit failed\n");
353ab6e9	82	mutex_unlock(&deflate_mutex);
1da177e4 LT	83	return -1;
	84	}
	85
	86	def_strm.next_in = data_in;
	87	def_strm.total_in = 0;
182ec4ee	88
1da177e4 LT	89	def_strm.next_out = cpage_out;
	90	def_strm.total_out = 0;
	91
	92	while (def_strm.total_out < dstlen - STREAM_END_SPACE && def_strm.total_in < sourcelen) {
	93	def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE);
	94	def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out);
	95	D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n",
	96	def_strm.avail_in, def_strm.avail_out));
	97	ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH);
182ec4ee	98	D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n",
1da177e4 LT	99	def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out));
	100	if (ret != Z_OK) {
	101	D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret));
	102	zlib_deflateEnd(&def_strm);
353ab6e9	103	mutex_unlock(&deflate_mutex);
1da177e4 LT	104	return -1;
	105	}
	106	}
	107	def_strm.avail_out += STREAM_END_SPACE;
	108	def_strm.avail_in = 0;
	109	ret = zlib_deflate(&def_strm, Z_FINISH);
	110	zlib_deflateEnd(&def_strm);
	111
	112	if (ret != Z_STREAM_END) {
	113	D1(printk(KERN_DEBUG "final deflate returned %d\n", ret));
	114	ret = -1;
	115	goto out;
	116	}
	117
	118	if (def_strm.total_out >= def_strm.total_in) {
	119	D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n",
	120	def_strm.total_in, def_strm.total_out));
	121	ret = -1;
	122	goto out;
	123	}
	124
	125	D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n",
	126	def_strm.total_in, def_strm.total_out));
	127
	128	*dstlen = def_strm.total_out;
	129	*sourcelen = def_strm.total_in;
	130	ret = 0;
	131	out:
353ab6e9	132	mutex_unlock(&deflate_mutex);
1da177e4 LT	133	return ret;
	134	}
	135
75c96f85 AB	136	static int jffs2_zlib_decompress(unsigned char *data_in,
75c96f85 AB	137	unsigned char *cpage_out,
088bd455	138	uint32_t srclen, uint32_t destlen)
1da177e4 LT	139	{
	140	int ret;
	141	int wbits = MAX_WBITS;
	142
353ab6e9	143	mutex_lock(&inflate_mutex);
1da177e4 LT	144
	145	inf_strm.next_in = data_in;
	146	inf_strm.avail_in = srclen;
	147	inf_strm.total_in = 0;
182ec4ee	148
1da177e4 LT	149	inf_strm.next_out = cpage_out;
	150	inf_strm.avail_out = destlen;
	151	inf_strm.total_out = 0;
	152
	153	/* If it's deflate, and it's got no preset dictionary, then
	154	we can tell zlib to skip the adler32 check. */
	155	if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
	156	((data_in[0] & 0x0f) == Z_DEFLATED) &&
	157	!(((data_in[0]<<8) + data_in[1]) % 31)) {
	158
	159	D2(printk(KERN_DEBUG "inflate skipping adler32\n"));
	160	wbits = -((data_in[0] >> 4) + 8);
	161	inf_strm.next_in += 2;
	162	inf_strm.avail_in -= 2;
	163	} else {
	164	/* Let this remain D1 for now -- it should never happen */
	165	D1(printk(KERN_DEBUG "inflate not skipping adler32\n"));
	166	}
	167
	168
	169	if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) {
	170	printk(KERN_WARNING "inflateInit failed\n");
353ab6e9	171	mutex_unlock(&inflate_mutex);
1da177e4 LT	172	return 1;
	173	}
	174
	175	while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK)
	176	;
	177	if (ret != Z_STREAM_END) {
	178	printk(KERN_NOTICE "inflate returned %d\n", ret);
	179	}
	180	zlib_inflateEnd(&inf_strm);
353ab6e9	181	mutex_unlock(&inflate_mutex);
ef53cb02	182	return 0;
1da177e4 LT	183	}
	184
	185	static struct jffs2_compressor jffs2_zlib_comp = {
	186	.priority = JFFS2_ZLIB_PRIORITY,
	187	.name = "zlib",
	188	.compr = JFFS2_COMPR_ZLIB,
	189	.compress = &jffs2_zlib_compress,
	190	.decompress = &jffs2_zlib_decompress,
	191	#ifdef JFFS2_ZLIB_DISABLED
	192	.disabled = 1,
	193	#else
	194	.disabled = 0,
	195	#endif
	196	};
	197
	198	int __init jffs2_zlib_init(void)
	199	{
	200	int ret;
	201
	202	ret = alloc_workspaces();
	203	if (ret)
ef53cb02	204	return ret;
1da177e4 LT	205
	206	ret = jffs2_register_compressor(&jffs2_zlib_comp);
	207	if (ret)
ef53cb02	208	free_workspaces();
1da177e4 LT	209
	210	return ret;
	211	}
	212
	213	void jffs2_zlib_exit(void)
	214	{
	215	jffs2_unregister_compressor(&jffs2_zlib_comp);
	216	free_workspaces();
	217	}