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

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
 * Copyright © 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>,
 *		    University of Szeged, Hungary
 *
 * Created by Arjan van de Ven <arjan@infradead.org>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include "compr.h"

static DEFINE_SPINLOCK(jffs2_compressor_list_lock);

/* Available compressors are on this list */
static LIST_HEAD(jffs2_compressor_list);

/* Actual compression mode */
static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;

/* Statistics for blocks stored without compression */
static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0;


/*
 * Return 1 to use this compression
 */
static int jffs2_is_best_compression(struct jffs2_compressor *this,
		struct jffs2_compressor *best, uint32_t size, uint32_t bestsize)
{
	switch (jffs2_compression_mode) {
	case JFFS2_COMPR_MODE_SIZE:
		if (bestsize > size)
			return 1;
		return 0;
	case JFFS2_COMPR_MODE_FAVOURLZO:
		if ((this->compr == JFFS2_COMPR_LZO) && (bestsize > size))
			return 1;
		if ((best->compr != JFFS2_COMPR_LZO) && (bestsize > size))
			return 1;
		if ((this->compr == JFFS2_COMPR_LZO) && (bestsize > (size * FAVOUR_LZO_PERCENT / 100)))
			return 1;
		if ((bestsize * FAVOUR_LZO_PERCENT / 100) > size)
			return 1;

		return 0;
	}
	/* Shouldn't happen */
	return 0;
}

/* jffs2_compress:
 * @data_in: Pointer to uncompressed data
 * @cpage_out: Pointer to returned pointer to buffer for compressed data
 * @datalen: On entry, holds the amount of data available for compression.
 *	On exit, expected to hold the amount of data actually compressed.
 * @cdatalen: On entry, holds the amount of space available for compressed
 *	data. On exit, expected to hold the actual size of the compressed
 *	data.
 *
 * Returns: Lower byte to be stored with data indicating compression type used.
 * Zero is used to show that the data could not be compressed - the
 * compressed version was actually larger than the original.
 * Upper byte will be used later. (soon)
 *
 * If the cdata buffer isn't large enough to hold all the uncompressed data,
 * jffs2_compress should compress as much as will fit, and should set
 * *datalen accordingly to show the amount of data which were compressed.
 */
uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
			unsigned char *data_in, unsigned char **cpage_out,
			uint32_t *datalen, uint32_t *cdatalen)
{
	int ret = JFFS2_COMPR_NONE;
	int compr_ret;
	struct jffs2_compressor *this, *best=NULL;
	unsigned char *output_buf = NULL, *tmp_buf;
	uint32_t orig_slen, orig_dlen;
	uint32_t best_slen=0, best_dlen=0;

	switch (jffs2_compression_mode) {
	case JFFS2_COMPR_MODE_NONE:
		break;
	case JFFS2_COMPR_MODE_PRIORITY:
		output_buf = kmalloc(*cdatalen,GFP_KERNEL);
		if (!output_buf) {
			printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n");
			goto out;
		}
		orig_slen = *datalen;
		orig_dlen = *cdatalen;
		spin_lock(&jffs2_compressor_list_lock);
		list_for_each_entry(this, &jffs2_compressor_list, list) {
			/* Skip decompress-only backwards-compatibility and disabled modules */
			if ((!this->compress)||(this->disabled))
				continue;

			this->usecount++;
			spin_unlock(&jffs2_compressor_list_lock);
			*datalen  = orig_slen;
			*cdatalen = orig_dlen;
			compr_ret = this->compress(data_in, output_buf, datalen, cdatalen);
			spin_lock(&jffs2_compressor_list_lock);
			this->usecount--;
			if (!compr_ret) {
				ret = this->compr;
				this->stat_compr_blocks++;
				this->stat_compr_orig_size += *datalen;
				this->stat_compr_new_size  += *cdatalen;
				break;
			}
		}
		spin_unlock(&jffs2_compressor_list_lock);
		if (ret == JFFS2_COMPR_NONE)
			kfree(output_buf);
		break;
	case JFFS2_COMPR_MODE_SIZE:
	case JFFS2_COMPR_MODE_FAVOURLZO:
		orig_slen = *datalen;
		orig_dlen = *cdatalen;
		spin_lock(&jffs2_compressor_list_lock);
		list_for_each_entry(this, &jffs2_compressor_list, list) {
			/* Skip decompress-only backwards-compatibility and disabled modules */
			if ((!this->compress)||(this->disabled))
				continue;
			/* Allocating memory for output buffer if necessary */
			if ((this->compr_buf_size < orig_slen) && (this->compr_buf)) {
				spin_unlock(&jffs2_compressor_list_lock);
				kfree(this->compr_buf);
				spin_lock(&jffs2_compressor_list_lock);
				this->compr_buf_size=0;
				this->compr_buf=NULL;
			}
			if (!this->compr_buf) {
				spin_unlock(&jffs2_compressor_list_lock);
				tmp_buf = kmalloc(orig_slen, GFP_KERNEL);
				spin_lock(&jffs2_compressor_list_lock);
				if (!tmp_buf) {
					printk(KERN_WARNING "JFFS2: No memory for compressor allocation. (%d bytes)\n", orig_slen);
					continue;
				}
				else {
					this->compr_buf = tmp_buf;
					this->compr_buf_size = orig_slen;
				}
			}
			this->usecount++;
			spin_unlock(&jffs2_compressor_list_lock);
			*datalen  = orig_slen;
			*cdatalen = orig_dlen;
			compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen);
			spin_lock(&jffs2_compressor_list_lock);
			this->usecount--;
			if (!compr_ret) {
				if (((!best_dlen) || jffs2_is_best_compression(this, best, *cdatalen, best_dlen))
						&& (*cdatalen < *datalen)) {
					best_dlen = *cdatalen;
					best_slen = *datalen;
					best = this;
				}
			}
		}
		if (best_dlen) {
			*cdatalen = best_dlen;
			*datalen  = best_slen;
			output_buf = best->compr_buf;
			best->compr_buf = NULL;
			best->compr_buf_size = 0;
			best->stat_compr_blocks++;
			best->stat_compr_orig_size += best_slen;
			best->stat_compr_new_size  += best_dlen;
			ret = best->compr;
		}
		spin_unlock(&jffs2_compressor_list_lock);
		break;
	default:
		printk(KERN_ERR "JFFS2: unknown compression mode.\n");
	}
 out:
	if (ret == JFFS2_COMPR_NONE) {
		*cpage_out = data_in;
		*datalen = *cdatalen;
		none_stat_compr_blocks++;
		none_stat_compr_size += *datalen;
	}
	else {
		*cpage_out = output_buf;
	}
	return ret;
}

int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
		     uint16_t comprtype, unsigned char *cdata_in,
		     unsigned char *data_out, uint32_t cdatalen, uint32_t datalen)
{
	struct jffs2_compressor *this;
	int ret;

	/* Older code had a bug where it would write non-zero 'usercompr'
	   fields. Deal with it. */
	if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB)
		comprtype &= 0xff;

	switch (comprtype & 0xff) {
	case JFFS2_COMPR_NONE:
		/* This should be special-cased elsewhere, but we might as well deal with it */
		memcpy(data_out, cdata_in, datalen);
		none_stat_decompr_blocks++;
		break;
	case JFFS2_COMPR_ZERO:
		memset(data_out, 0, datalen);
		break;
	default:
		spin_lock(&jffs2_compressor_list_lock);
		list_for_each_entry(this, &jffs2_compressor_list, list) {
			if (comprtype == this->compr) {
				this->usecount++;
				spin_unlock(&jffs2_compressor_list_lock);
				ret = this->decompress(cdata_in, data_out, cdatalen, datalen);
				spin_lock(&jffs2_compressor_list_lock);
				if (ret) {
					printk(KERN_WARNING "Decompressor \"%s\" returned %d\n", this->name, ret);
				}
				else {
					this->stat_decompr_blocks++;
				}
				this->usecount--;
				spin_unlock(&jffs2_compressor_list_lock);
				return ret;
			}
		}
		printk(KERN_WARNING "JFFS2 compression type 0x%02x not available.\n", comprtype);
		spin_unlock(&jffs2_compressor_list_lock);
		return -EIO;
	}
	return 0;
}

int jffs2_register_compressor(struct jffs2_compressor *comp)
{
	struct jffs2_compressor *this;

	if (!comp->name) {
		printk(KERN_WARNING "NULL compressor name at registering JFFS2 compressor. Failed.\n");
		return -1;
	}
	comp->compr_buf_size=0;
	comp->compr_buf=NULL;
	comp->usecount=0;
	comp->stat_compr_orig_size=0;
	comp->stat_compr_new_size=0;
	comp->stat_compr_blocks=0;
	comp->stat_decompr_blocks=0;
	D1(printk(KERN_DEBUG "Registering JFFS2 compressor \"%s\"\n", comp->name));

	spin_lock(&jffs2_compressor_list_lock);

	list_for_each_entry(this, &jffs2_compressor_list, list) {
		if (this->priority < comp->priority) {
			list_add(&comp->list, this->list.prev);
			goto out;
		}
	}
	list_add_tail(&comp->list, &jffs2_compressor_list);
out:
	D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
		printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
	})

	spin_unlock(&jffs2_compressor_list_lock);

	return 0;
}

int jffs2_unregister_compressor(struct jffs2_compressor *comp)
{
	D2(struct jffs2_compressor *this;)

	D1(printk(KERN_DEBUG "Unregistering JFFS2 compressor \"%s\"\n", comp->name));

	spin_lock(&jffs2_compressor_list_lock);

	if (comp->usecount) {
		spin_unlock(&jffs2_compressor_list_lock);
		printk(KERN_WARNING "JFFS2: Compressor modul is in use. Unregister failed.\n");
		return -1;
	}
	list_del(&comp->list);

	D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
		printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
	})
	spin_unlock(&jffs2_compressor_list_lock);
	return 0;
}

void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig)
{
	if (orig != comprbuf)
		kfree(comprbuf);
}

int __init jffs2_compressors_init(void)
{
/* Registering compressors */
#ifdef CONFIG_JFFS2_ZLIB
	jffs2_zlib_init();
#endif
#ifdef CONFIG_JFFS2_RTIME
	jffs2_rtime_init();
#endif
#ifdef CONFIG_JFFS2_RUBIN
	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;
	D1(printk(KERN_INFO "JFFS2: default compression mode: none\n");)
#else
#ifdef CONFIG_JFFS2_CMODE_SIZE
	jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
	D1(printk(KERN_INFO "JFFS2: default compression mode: size\n");)
#else
#ifdef CONFIG_JFFS2_CMODE_FAVOURLZO
	jffs2_compression_mode = JFFS2_COMPR_MODE_FAVOURLZO;
	D1(printk(KERN_INFO "JFFS2: default compression mode: favourlzo\n");)
#else
	D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");)
#endif
#endif
#endif
	return 0;
}

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();
#endif
#ifdef CONFIG_JFFS2_RTIME
	jffs2_rtime_exit();
#endif
#ifdef CONFIG_JFFS2_ZLIB
	jffs2_zlib_exit();
#endif
	return 0;
}
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>
c00c310e	6	* Copyright © 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>,
ef53cb02	7	* University of Szeged, Hungary
1da177e4	8	*
6088c058 DW	9	* Created by Arjan van de Ven <arjan@infradead.org>
6088c058 DW	10	*
1da177e4 LT	11	* For licensing information, see the file 'LICENCE' in this directory.
1da177e4 LT	12	*
1da177e4 LT	13	*/
	14
	15	#include "compr.h"
	16
	17	static DEFINE_SPINLOCK(jffs2_compressor_list_lock);
	18
	19	/* Available compressors are on this list */
	20	static LIST_HEAD(jffs2_compressor_list);
	21
	22	/* Actual compression mode */
	23	static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
	24
	25	/* Statistics for blocks stored without compression */
	26	static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0;
	27
3b23c1f5 RP	28
	29	/*
	30	* Return 1 to use this compression
	31	*/
	32	static int jffs2_is_best_compression(struct jffs2_compressor *this,
	33	struct jffs2_compressor *best, uint32_t size, uint32_t bestsize)
	34	{
	35	switch (jffs2_compression_mode) {
	36	case JFFS2_COMPR_MODE_SIZE:
	37	if (bestsize > size)
	38	return 1;
	39	return 0;
	40	case JFFS2_COMPR_MODE_FAVOURLZO:
	41	if ((this->compr == JFFS2_COMPR_LZO) && (bestsize > size))
	42	return 1;
	43	if ((best->compr != JFFS2_COMPR_LZO) && (bestsize > size))
	44	return 1;
	45	if ((this->compr == JFFS2_COMPR_LZO) && (bestsize > (size * FAVOUR_LZO_PERCENT / 100)))
	46	return 1;
	47	if ((bestsize * FAVOUR_LZO_PERCENT / 100) > size)
	48	return 1;
	49
	50	return 0;
	51	}
	52	/* Shouldn't happen */
	53	return 0;
	54	}
	55
1da177e4	56	/* jffs2_compress:
faa5c2a1 GU	57	* @data_in: Pointer to uncompressed data
faa5c2a1 GU	58	* @cpage_out: Pointer to returned pointer to buffer for compressed data
1da177e4 LT	59	* @datalen: On entry, holds the amount of data available for compression.
	60	* On exit, expected to hold the amount of data actually compressed.
	61	* @cdatalen: On entry, holds the amount of space available for compressed
	62	* data. On exit, expected to hold the actual size of the compressed
	63	* data.
	64	*
	65	* Returns: Lower byte to be stored with data indicating compression type used.
182ec4ee	66	* Zero is used to show that the data could not be compressed - the
1da177e4 LT	67	* compressed version was actually larger than the original.
	68	* Upper byte will be used later. (soon)
	69	*
	70	* If the cdata buffer isn't large enough to hold all the uncompressed data,
182ec4ee	71	* jffs2_compress should compress as much as will fit, and should set
1da177e4 LT	72	* *datalen accordingly to show the amount of data which were compressed.
	73	*/
	74	uint16_t jffs2_compress(struct jffs2_sb_info c, struct jffs2_inode_info f,
ef53cb02 DW	75	unsigned char data_in, unsigned char *cpage_out,
ef53cb02 DW	76	uint32_t datalen, uint32_t cdatalen)
1da177e4 LT	77	{
1da177e4 LT	78	int ret = JFFS2_COMPR_NONE;
ef53cb02 DW	79	int compr_ret;
	80	struct jffs2_compressor this, best=NULL;
	81	unsigned char output_buf = NULL, tmp_buf;
	82	uint32_t orig_slen, orig_dlen;
	83	uint32_t best_slen=0, best_dlen=0;
1da177e4	84
ef53cb02 DW	85	switch (jffs2_compression_mode) {
	86	case JFFS2_COMPR_MODE_NONE:
	87	break;
	88	case JFFS2_COMPR_MODE_PRIORITY:
	89	output_buf = kmalloc(*cdatalen,GFP_KERNEL);
	90	if (!output_buf) {
	91	printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n");
	92	goto out;
	93	}
	94	orig_slen = *datalen;
	95	orig_dlen = *cdatalen;
	96	spin_lock(&jffs2_compressor_list_lock);
	97	list_for_each_entry(this, &jffs2_compressor_list, list) {
	98	/* Skip decompress-only backwards-compatibility and disabled modules */
	99	if ((!this->compress)\|\|(this->disabled))
	100	continue;
1da177e4	101
ef53cb02 DW	102	this->usecount++;
	103	spin_unlock(&jffs2_compressor_list_lock);
	104	*datalen = orig_slen;
	105	*cdatalen = orig_dlen;
088bd455	106	compr_ret = this->compress(data_in, output_buf, datalen, cdatalen);
ef53cb02 DW	107	spin_lock(&jffs2_compressor_list_lock);
	108	this->usecount--;
	109	if (!compr_ret) {
	110	ret = this->compr;
	111	this->stat_compr_blocks++;
	112	this->stat_compr_orig_size += *datalen;
	113	this->stat_compr_new_size += *cdatalen;
	114	break;
	115	}
	116	}
	117	spin_unlock(&jffs2_compressor_list_lock);
	118	if (ret == JFFS2_COMPR_NONE)
	119	kfree(output_buf);
	120	break;
	121	case JFFS2_COMPR_MODE_SIZE:
3b23c1f5	122	case JFFS2_COMPR_MODE_FAVOURLZO:
ef53cb02 DW	123	orig_slen = *datalen;
	124	orig_dlen = *cdatalen;
	125	spin_lock(&jffs2_compressor_list_lock);
	126	list_for_each_entry(this, &jffs2_compressor_list, list) {
	127	/* Skip decompress-only backwards-compatibility and disabled modules */
	128	if ((!this->compress)\|\|(this->disabled))
	129	continue;
	130	/* Allocating memory for output buffer if necessary */
3b23c1f5	131	if ((this->compr_buf_size < orig_slen) && (this->compr_buf)) {
ef53cb02 DW	132	spin_unlock(&jffs2_compressor_list_lock);
	133	kfree(this->compr_buf);
	134	spin_lock(&jffs2_compressor_list_lock);
	135	this->compr_buf_size=0;
	136	this->compr_buf=NULL;
	137	}
	138	if (!this->compr_buf) {
	139	spin_unlock(&jffs2_compressor_list_lock);
3b23c1f5	140	tmp_buf = kmalloc(orig_slen, GFP_KERNEL);
ef53cb02 DW	141	spin_lock(&jffs2_compressor_list_lock);
ef53cb02 DW	142	if (!tmp_buf) {
3b23c1f5	143	printk(KERN_WARNING "JFFS2: No memory for compressor allocation. (%d bytes)\n", orig_slen);
ef53cb02 DW	144	continue;
	145	}
	146	else {
	147	this->compr_buf = tmp_buf;
3b23c1f5	148	this->compr_buf_size = orig_slen;
ef53cb02 DW	149	}
	150	}
	151	this->usecount++;
	152	spin_unlock(&jffs2_compressor_list_lock);
	153	*datalen = orig_slen;
	154	*cdatalen = orig_dlen;
088bd455	155	compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen);
ef53cb02 DW	156	spin_lock(&jffs2_compressor_list_lock);
	157	this->usecount--;
	158	if (!compr_ret) {
3b23c1f5 RP	159	if (((!best_dlen) \|\| jffs2_is_best_compression(this, best, *cdatalen, best_dlen))
3b23c1f5 RP	160	&& (cdatalen < datalen)) {
ef53cb02 DW	161	best_dlen = *cdatalen;
	162	best_slen = *datalen;
	163	best = this;
	164	}
	165	}
	166	}
	167	if (best_dlen) {
	168	*cdatalen = best_dlen;
	169	*datalen = best_slen;
	170	output_buf = best->compr_buf;
	171	best->compr_buf = NULL;
	172	best->compr_buf_size = 0;
	173	best->stat_compr_blocks++;
	174	best->stat_compr_orig_size += best_slen;
	175	best->stat_compr_new_size += best_dlen;
	176	ret = best->compr;
	177	}
	178	spin_unlock(&jffs2_compressor_list_lock);
	179	break;
	180	default:
af901ca1	181	printk(KERN_ERR "JFFS2: unknown compression mode.\n");
ef53cb02	182	}
1da177e4	183	out:
ef53cb02 DW	184	if (ret == JFFS2_COMPR_NONE) {
	185	*cpage_out = data_in;
	186	datalen = cdatalen;
	187	none_stat_compr_blocks++;
	188	none_stat_compr_size += *datalen;
	189	}
	190	else {
	191	*cpage_out = output_buf;
	192	}
1da177e4 LT	193	return ret;
	194	}
	195
	196	int jffs2_decompress(struct jffs2_sb_info c, struct jffs2_inode_info f,
182ec4ee	197	uint16_t comprtype, unsigned char *cdata_in,
1da177e4 LT	198	unsigned char *data_out, uint32_t cdatalen, uint32_t datalen)
1da177e4 LT	199	{
ef53cb02 DW	200	struct jffs2_compressor *this;
ef53cb02 DW	201	int ret;
1da177e4 LT	202
	203	/* Older code had a bug where it would write non-zero 'usercompr'
	204	fields. Deal with it. */
	205	if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB)
	206	comprtype &= 0xff;
	207
	208	switch (comprtype & 0xff) {
	209	case JFFS2_COMPR_NONE:
	210	/* This should be special-cased elsewhere, but we might as well deal with it */
	211	memcpy(data_out, cdata_in, datalen);
ef53cb02	212	none_stat_decompr_blocks++;
1da177e4 LT	213	break;
	214	case JFFS2_COMPR_ZERO:
	215	memset(data_out, 0, datalen);
	216	break;
	217	default:
ef53cb02 DW	218	spin_lock(&jffs2_compressor_list_lock);
	219	list_for_each_entry(this, &jffs2_compressor_list, list) {
	220	if (comprtype == this->compr) {
	221	this->usecount++;
	222	spin_unlock(&jffs2_compressor_list_lock);
088bd455	223	ret = this->decompress(cdata_in, data_out, cdatalen, datalen);
ef53cb02 DW	224	spin_lock(&jffs2_compressor_list_lock);
	225	if (ret) {
	226	printk(KERN_WARNING "Decompressor \"%s\" returned %d\n", this->name, ret);
	227	}
	228	else {
	229	this->stat_decompr_blocks++;
	230	}
	231	this->usecount--;
	232	spin_unlock(&jffs2_compressor_list_lock);
	233	return ret;
	234	}
	235	}
1da177e4	236	printk(KERN_WARNING "JFFS2 compression type 0x%02x not available.\n", comprtype);
ef53cb02	237	spin_unlock(&jffs2_compressor_list_lock);
1da177e4 LT	238	return -EIO;
	239	}
	240	return 0;
	241	}
	242
	243	int jffs2_register_compressor(struct jffs2_compressor *comp)
	244	{
ef53cb02	245	struct jffs2_compressor *this;
1da177e4	246
ef53cb02 DW	247	if (!comp->name) {
	248	printk(KERN_WARNING "NULL compressor name at registering JFFS2 compressor. Failed.\n");
	249	return -1;
	250	}
	251	comp->compr_buf_size=0;
	252	comp->compr_buf=NULL;
	253	comp->usecount=0;
	254	comp->stat_compr_orig_size=0;
	255	comp->stat_compr_new_size=0;
	256	comp->stat_compr_blocks=0;
	257	comp->stat_decompr_blocks=0;
	258	D1(printk(KERN_DEBUG "Registering JFFS2 compressor \"%s\"\n", comp->name));
1da177e4	259
ef53cb02	260	spin_lock(&jffs2_compressor_list_lock);
1da177e4	261
ef53cb02 DW	262	list_for_each_entry(this, &jffs2_compressor_list, list) {
	263	if (this->priority < comp->priority) {
	264	list_add(&comp->list, this->list.prev);
	265	goto out;
	266	}
	267	}
	268	list_add_tail(&comp->list, &jffs2_compressor_list);
1da177e4	269	out:
ef53cb02 DW	270	D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
	271	printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
	272	})
1da177e4	273
ef53cb02	274	spin_unlock(&jffs2_compressor_list_lock);
1da177e4	275
ef53cb02	276	return 0;
1da177e4 LT	277	}
	278
	279	int jffs2_unregister_compressor(struct jffs2_compressor *comp)
	280	{
ef53cb02	281	D2(struct jffs2_compressor *this;)
1da177e4	282
ef53cb02	283	D1(printk(KERN_DEBUG "Unregistering JFFS2 compressor \"%s\"\n", comp->name));
1da177e4	284
ef53cb02	285	spin_lock(&jffs2_compressor_list_lock);
1da177e4	286
ef53cb02 DW	287	if (comp->usecount) {
	288	spin_unlock(&jffs2_compressor_list_lock);
	289	printk(KERN_WARNING "JFFS2: Compressor modul is in use. Unregister failed.\n");
	290	return -1;
	291	}
	292	list_del(&comp->list);
1da177e4	293
ef53cb02 DW	294	D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
	295	printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
	296	})
	297	spin_unlock(&jffs2_compressor_list_lock);
	298	return 0;
1da177e4 LT	299	}
1da177e4 LT	300
1da177e4 LT	301	void jffs2_free_comprbuf(unsigned char comprbuf, unsigned char orig)
1da177e4 LT	302	{
ef53cb02 DW	303	if (orig != comprbuf)
ef53cb02 DW	304	kfree(comprbuf);
1da177e4 LT	305	}
1da177e4 LT	306
7d2beb13	307	int __init jffs2_compressors_init(void)
1da177e4 LT	308	{
	309	/* Registering compressors */
	310	#ifdef CONFIG_JFFS2_ZLIB
ef53cb02	311	jffs2_zlib_init();
1da177e4 LT	312	#endif
1da177e4 LT	313	#ifdef CONFIG_JFFS2_RTIME
ef53cb02	314	jffs2_rtime_init();
1da177e4 LT	315	#endif
1da177e4 LT	316	#ifdef CONFIG_JFFS2_RUBIN
ef53cb02 DW	317	jffs2_rubinmips_init();
ef53cb02 DW	318	jffs2_dynrubin_init();
1da177e4	319	#endif
c799aca3 RP	320	#ifdef CONFIG_JFFS2_LZO
	321	jffs2_lzo_init();
	322	#endif
1da177e4 LT	323	/* Setting default compression mode */
1da177e4 LT	324	#ifdef CONFIG_JFFS2_CMODE_NONE
ef53cb02 DW	325	jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
ef53cb02 DW	326	D1(printk(KERN_INFO "JFFS2: default compression mode: none\n");)
1da177e4 LT	327	#else
1da177e4 LT	328	#ifdef CONFIG_JFFS2_CMODE_SIZE
ef53cb02 DW	329	jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
ef53cb02 DW	330	D1(printk(KERN_INFO "JFFS2: default compression mode: size\n");)
3b23c1f5 RP	331	#else
	332	#ifdef CONFIG_JFFS2_CMODE_FAVOURLZO
	333	jffs2_compression_mode = JFFS2_COMPR_MODE_FAVOURLZO;
	334	D1(printk(KERN_INFO "JFFS2: default compression mode: favourlzo\n");)
1da177e4	335	#else
ef53cb02	336	D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");)
1da177e4	337	#endif
3b23c1f5	338	#endif
1da177e4	339	#endif
ef53cb02	340	return 0;
1da177e4 LT	341	}
1da177e4 LT	342
3bcc86f5	343	int jffs2_compressors_exit(void)
1da177e4 LT	344	{
1da177e4 LT	345	/* Unregistering compressors */
c799aca3 RP	346	#ifdef CONFIG_JFFS2_LZO
	347	jffs2_lzo_exit();
	348	#endif
1da177e4	349	#ifdef CONFIG_JFFS2_RUBIN
ef53cb02 DW	350	jffs2_dynrubin_exit();
ef53cb02 DW	351	jffs2_rubinmips_exit();
1da177e4 LT	352	#endif
1da177e4 LT	353	#ifdef CONFIG_JFFS2_RTIME
ef53cb02	354	jffs2_rtime_exit();
1da177e4 LT	355	#endif
1da177e4 LT	356	#ifdef CONFIG_JFFS2_ZLIB
ef53cb02	357	jffs2_zlib_exit();
1da177e4	358	#endif
ef53cb02	359	return 0;
1da177e4	360	}