458 lines
17 KiB
C
458 lines
17 KiB
C
/*
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* JFFS2 -- Journalling Flash File System, Version 2.
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*
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* Copyright (C) 2001-2003 Red Hat, Inc.
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* Created by Arjan van de Ven <arjanv@redhat.com>
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*
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* Copyright (C) 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>,
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* University of Szeged, Hungary
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*
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* For licensing information, see the file 'LICENCE' in this directory.
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*
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* $Id: compr.c,v 1.45 2005/07/26 13:24:40 havasi Exp $
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*
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*/
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#include "compr.h"
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static DEFINE_SPINLOCK(jffs2_compressor_list_lock);
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/* Available compressors are on this list */
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static LIST_HEAD(jffs2_compressor_list);
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/* Actual compression mode */
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static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
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/* Statistics for blocks stored without compression */
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static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0;
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/* jffs2_compress:
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* @data: Pointer to uncompressed data
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* @cdata: Pointer to returned pointer to buffer for compressed data
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* @datalen: On entry, holds the amount of data available for compression.
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* On exit, expected to hold the amount of data actually compressed.
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* @cdatalen: On entry, holds the amount of space available for compressed
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* data. On exit, expected to hold the actual size of the compressed
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* data.
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*
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* Returns: Lower byte to be stored with data indicating compression type used.
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* Zero is used to show that the data could not be compressed - the
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* compressed version was actually larger than the original.
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* Upper byte will be used later. (soon)
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*
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* If the cdata buffer isn't large enough to hold all the uncompressed data,
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* jffs2_compress should compress as much as will fit, and should set
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* *datalen accordingly to show the amount of data which were compressed.
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*/
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uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
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unsigned char *data_in, unsigned char **cpage_out,
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uint32_t *datalen, uint32_t *cdatalen)
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{
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int ret = JFFS2_COMPR_NONE;
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int compr_ret;
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struct jffs2_compressor *this, *best=NULL;
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unsigned char *output_buf = NULL, *tmp_buf;
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uint32_t orig_slen, orig_dlen;
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uint32_t best_slen=0, best_dlen=0;
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switch (jffs2_compression_mode) {
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case JFFS2_COMPR_MODE_NONE:
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break;
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case JFFS2_COMPR_MODE_PRIORITY:
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output_buf = kmalloc(*cdatalen,GFP_KERNEL);
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if (!output_buf) {
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printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n");
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goto out;
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}
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orig_slen = *datalen;
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orig_dlen = *cdatalen;
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spin_lock(&jffs2_compressor_list_lock);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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/* Skip decompress-only backwards-compatibility and disabled modules */
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if ((!this->compress)||(this->disabled))
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continue;
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this->usecount++;
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spin_unlock(&jffs2_compressor_list_lock);
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*datalen = orig_slen;
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*cdatalen = orig_dlen;
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compr_ret = this->compress(data_in, output_buf, datalen, cdatalen, NULL);
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spin_lock(&jffs2_compressor_list_lock);
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this->usecount--;
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if (!compr_ret) {
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ret = this->compr;
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this->stat_compr_blocks++;
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this->stat_compr_orig_size += *datalen;
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this->stat_compr_new_size += *cdatalen;
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break;
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}
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}
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spin_unlock(&jffs2_compressor_list_lock);
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if (ret == JFFS2_COMPR_NONE) kfree(output_buf);
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break;
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case JFFS2_COMPR_MODE_SIZE:
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orig_slen = *datalen;
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orig_dlen = *cdatalen;
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spin_lock(&jffs2_compressor_list_lock);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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/* Skip decompress-only backwards-compatibility and disabled modules */
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if ((!this->compress)||(this->disabled))
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continue;
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/* Allocating memory for output buffer if necessary */
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if ((this->compr_buf_size<orig_dlen)&&(this->compr_buf)) {
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spin_unlock(&jffs2_compressor_list_lock);
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kfree(this->compr_buf);
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spin_lock(&jffs2_compressor_list_lock);
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this->compr_buf_size=0;
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this->compr_buf=NULL;
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}
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if (!this->compr_buf) {
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spin_unlock(&jffs2_compressor_list_lock);
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tmp_buf = kmalloc(orig_dlen,GFP_KERNEL);
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spin_lock(&jffs2_compressor_list_lock);
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if (!tmp_buf) {
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printk(KERN_WARNING "JFFS2: No memory for compressor allocation. (%d bytes)\n",orig_dlen);
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continue;
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}
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else {
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this->compr_buf = tmp_buf;
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this->compr_buf_size = orig_dlen;
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}
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}
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this->usecount++;
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spin_unlock(&jffs2_compressor_list_lock);
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*datalen = orig_slen;
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*cdatalen = orig_dlen;
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compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen, NULL);
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spin_lock(&jffs2_compressor_list_lock);
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this->usecount--;
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if (!compr_ret) {
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if ((!best_dlen)||(best_dlen>*cdatalen)) {
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best_dlen = *cdatalen;
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best_slen = *datalen;
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best = this;
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}
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}
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}
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if (best_dlen) {
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*cdatalen = best_dlen;
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*datalen = best_slen;
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output_buf = best->compr_buf;
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best->compr_buf = NULL;
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best->compr_buf_size = 0;
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best->stat_compr_blocks++;
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best->stat_compr_orig_size += best_slen;
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best->stat_compr_new_size += best_dlen;
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ret = best->compr;
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}
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spin_unlock(&jffs2_compressor_list_lock);
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break;
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default:
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printk(KERN_ERR "JFFS2: unknow compression mode.\n");
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}
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out:
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if (ret == JFFS2_COMPR_NONE) {
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*cpage_out = data_in;
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*datalen = *cdatalen;
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none_stat_compr_blocks++;
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none_stat_compr_size += *datalen;
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}
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else {
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*cpage_out = output_buf;
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}
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return ret;
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}
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int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
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uint16_t comprtype, unsigned char *cdata_in,
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unsigned char *data_out, uint32_t cdatalen, uint32_t datalen)
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{
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struct jffs2_compressor *this;
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int ret;
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/* Older code had a bug where it would write non-zero 'usercompr'
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fields. Deal with it. */
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if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB)
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comprtype &= 0xff;
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switch (comprtype & 0xff) {
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case JFFS2_COMPR_NONE:
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/* This should be special-cased elsewhere, but we might as well deal with it */
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memcpy(data_out, cdata_in, datalen);
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none_stat_decompr_blocks++;
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break;
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case JFFS2_COMPR_ZERO:
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memset(data_out, 0, datalen);
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break;
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default:
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spin_lock(&jffs2_compressor_list_lock);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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if (comprtype == this->compr) {
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this->usecount++;
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spin_unlock(&jffs2_compressor_list_lock);
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ret = this->decompress(cdata_in, data_out, cdatalen, datalen, NULL);
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spin_lock(&jffs2_compressor_list_lock);
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if (ret) {
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printk(KERN_WARNING "Decompressor \"%s\" returned %d\n", this->name, ret);
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}
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else {
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this->stat_decompr_blocks++;
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}
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this->usecount--;
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spin_unlock(&jffs2_compressor_list_lock);
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return ret;
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}
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}
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printk(KERN_WARNING "JFFS2 compression type 0x%02x not available.\n", comprtype);
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spin_unlock(&jffs2_compressor_list_lock);
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return -EIO;
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}
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return 0;
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}
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int jffs2_register_compressor(struct jffs2_compressor *comp)
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{
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struct jffs2_compressor *this;
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if (!comp->name) {
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printk(KERN_WARNING "NULL compressor name at registering JFFS2 compressor. Failed.\n");
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return -1;
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}
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comp->compr_buf_size=0;
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comp->compr_buf=NULL;
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comp->usecount=0;
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comp->stat_compr_orig_size=0;
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comp->stat_compr_new_size=0;
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comp->stat_compr_blocks=0;
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comp->stat_decompr_blocks=0;
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D1(printk(KERN_DEBUG "Registering JFFS2 compressor \"%s\"\n", comp->name));
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spin_lock(&jffs2_compressor_list_lock);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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if (this->priority < comp->priority) {
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list_add(&comp->list, this->list.prev);
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goto out;
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}
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}
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list_add_tail(&comp->list, &jffs2_compressor_list);
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out:
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D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
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printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
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})
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spin_unlock(&jffs2_compressor_list_lock);
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return 0;
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}
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int jffs2_unregister_compressor(struct jffs2_compressor *comp)
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{
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D2(struct jffs2_compressor *this;)
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D1(printk(KERN_DEBUG "Unregistering JFFS2 compressor \"%s\"\n", comp->name));
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spin_lock(&jffs2_compressor_list_lock);
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if (comp->usecount) {
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spin_unlock(&jffs2_compressor_list_lock);
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printk(KERN_WARNING "JFFS2: Compressor modul is in use. Unregister failed.\n");
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return -1;
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}
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list_del(&comp->list);
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D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
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printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
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})
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spin_unlock(&jffs2_compressor_list_lock);
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return 0;
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}
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#ifdef CONFIG_JFFS2_PROC
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#define JFFS2_STAT_BUF_SIZE 16000
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char *jffs2_list_compressors(void)
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{
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struct jffs2_compressor *this;
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char *buf, *act_buf;
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act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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act_buf += sprintf(act_buf, "%10s priority:%d ", this->name, this->priority);
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if ((this->disabled)||(!this->compress))
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act_buf += sprintf(act_buf,"disabled");
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else
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act_buf += sprintf(act_buf,"enabled");
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act_buf += sprintf(act_buf,"\n");
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}
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return buf;
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}
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char *jffs2_stats(void)
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{
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struct jffs2_compressor *this;
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char *buf, *act_buf;
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act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL);
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act_buf += sprintf(act_buf,"JFFS2 compressor statistics:\n");
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act_buf += sprintf(act_buf,"%10s ","none");
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act_buf += sprintf(act_buf,"compr: %d blocks (%d) decompr: %d blocks\n", none_stat_compr_blocks,
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none_stat_compr_size, none_stat_decompr_blocks);
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spin_lock(&jffs2_compressor_list_lock);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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act_buf += sprintf(act_buf,"%10s ",this->name);
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if ((this->disabled)||(!this->compress))
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act_buf += sprintf(act_buf,"- ");
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else
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act_buf += sprintf(act_buf,"+ ");
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act_buf += sprintf(act_buf,"compr: %d blocks (%d/%d) decompr: %d blocks ", this->stat_compr_blocks,
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this->stat_compr_new_size, this->stat_compr_orig_size,
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this->stat_decompr_blocks);
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act_buf += sprintf(act_buf,"\n");
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}
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spin_unlock(&jffs2_compressor_list_lock);
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return buf;
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}
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char *jffs2_get_compression_mode_name(void)
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{
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switch (jffs2_compression_mode) {
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case JFFS2_COMPR_MODE_NONE:
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return "none";
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case JFFS2_COMPR_MODE_PRIORITY:
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return "priority";
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case JFFS2_COMPR_MODE_SIZE:
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return "size";
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}
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return "unkown";
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}
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int jffs2_set_compression_mode_name(const char *name)
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{
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if (!strcmp("none",name)) {
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jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
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return 0;
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}
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if (!strcmp("priority",name)) {
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jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
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return 0;
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}
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if (!strcmp("size",name)) {
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jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
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return 0;
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}
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return 1;
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}
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static int jffs2_compressor_Xable(const char *name, int disabled)
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{
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struct jffs2_compressor *this;
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spin_lock(&jffs2_compressor_list_lock);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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if (!strcmp(this->name, name)) {
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this->disabled = disabled;
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spin_unlock(&jffs2_compressor_list_lock);
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return 0;
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}
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}
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spin_unlock(&jffs2_compressor_list_lock);
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printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name);
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return 1;
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}
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int jffs2_enable_compressor_name(const char *name)
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{
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return jffs2_compressor_Xable(name, 0);
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}
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int jffs2_disable_compressor_name(const char *name)
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{
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return jffs2_compressor_Xable(name, 1);
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}
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int jffs2_set_compressor_priority(const char *name, int priority)
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{
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struct jffs2_compressor *this,*comp;
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spin_lock(&jffs2_compressor_list_lock);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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if (!strcmp(this->name, name)) {
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this->priority = priority;
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comp = this;
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goto reinsert;
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}
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}
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spin_unlock(&jffs2_compressor_list_lock);
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printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name);
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return 1;
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reinsert:
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/* list is sorted in the order of priority, so if
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we change it we have to reinsert it into the
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good place */
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list_del(&comp->list);
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list_for_each_entry(this, &jffs2_compressor_list, list) {
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if (this->priority < comp->priority) {
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list_add(&comp->list, this->list.prev);
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spin_unlock(&jffs2_compressor_list_lock);
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return 0;
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}
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}
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list_add_tail(&comp->list, &jffs2_compressor_list);
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spin_unlock(&jffs2_compressor_list_lock);
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return 0;
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}
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#endif
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void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig)
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{
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if (orig != comprbuf)
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kfree(comprbuf);
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}
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int jffs2_compressors_init(void)
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{
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/* Registering compressors */
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#ifdef CONFIG_JFFS2_ZLIB
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jffs2_zlib_init();
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#endif
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#ifdef CONFIG_JFFS2_RTIME
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jffs2_rtime_init();
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#endif
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#ifdef CONFIG_JFFS2_RUBIN
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jffs2_rubinmips_init();
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jffs2_dynrubin_init();
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#endif
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/* Setting default compression mode */
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#ifdef CONFIG_JFFS2_CMODE_NONE
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jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
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D1(printk(KERN_INFO "JFFS2: default compression mode: none\n");)
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#else
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#ifdef CONFIG_JFFS2_CMODE_SIZE
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jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
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D1(printk(KERN_INFO "JFFS2: default compression mode: size\n");)
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#else
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D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");)
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#endif
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#endif
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return 0;
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}
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int jffs2_compressors_exit(void)
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{
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/* Unregistering compressors */
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#ifdef CONFIG_JFFS2_RUBIN
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jffs2_dynrubin_exit();
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jffs2_rubinmips_exit();
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#endif
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#ifdef CONFIG_JFFS2_RTIME
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jffs2_rtime_exit();
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#endif
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#ifdef CONFIG_JFFS2_ZLIB
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jffs2_zlib_exit();
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#endif
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return 0;
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}
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