diff options
Diffstat (limited to 'fs/jffs2/compr.c')
| -rw-r--r-- | fs/jffs2/compr.c | 469 |
1 files changed, 469 insertions, 0 deletions
diff --git a/fs/jffs2/compr.c b/fs/jffs2/compr.c new file mode 100644 index 000000000000..af922a9618ac --- /dev/null +++ b/fs/jffs2/compr.c @@ -0,0 +1,469 @@ +/* + * JFFS2 -- Journalling Flash File System, Version 2. + * + * Copyright (C) 2001-2003 Red Hat, Inc. + * Created by Arjan van de Ven <arjanv@redhat.com> + * + * Copyright (C) 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>, + * University of Szeged, Hungary + * + * For licensing information, see the file 'LICENCE' in this directory. + * + * $Id: compr.c,v 1.42 2004/08/07 21:56:08 dwmw2 Exp $ + * + */ + +#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; + +/* jffs2_compress: + * @data: Pointer to uncompressed data + * @cdata: 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, NULL); + 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: + 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_dlen)&&(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_dlen,GFP_KERNEL); + spin_lock(&jffs2_compressor_list_lock); + if (!tmp_buf) { + printk(KERN_WARNING "JFFS2: No memory for compressor allocation. (%d bytes)\n",orig_dlen); + continue; + } + else { + this->compr_buf = tmp_buf; + this->compr_buf_size = orig_dlen; + } + } + 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, NULL); + spin_lock(&jffs2_compressor_list_lock); + this->usecount--; + if (!compr_ret) { + if ((!best_dlen)||(best_dlen>*cdatalen)) { + 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: unknow 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, NULL); + 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; +} + +#ifdef CONFIG_JFFS2_PROC + +#define JFFS2_STAT_BUF_SIZE 16000 + +char *jffs2_list_compressors(void) +{ + struct jffs2_compressor *this; + char *buf, *act_buf; + + act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL); + list_for_each_entry(this, &jffs2_compressor_list, list) { + act_buf += sprintf(act_buf, "%10s priority:%d ", this->name, this->priority); + if ((this->disabled)||(!this->compress)) + act_buf += sprintf(act_buf,"disabled"); + else + act_buf += sprintf(act_buf,"enabled"); + act_buf += sprintf(act_buf,"\n"); + } + return buf; +} + +char *jffs2_stats(void) +{ + struct jffs2_compressor *this; + char *buf, *act_buf; + + act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL); + + act_buf += sprintf(act_buf,"JFFS2 compressor statistics:\n"); + act_buf += sprintf(act_buf,"%10s ","none"); + act_buf += sprintf(act_buf,"compr: %d blocks (%d) decompr: %d blocks\n", none_stat_compr_blocks, + none_stat_compr_size, none_stat_decompr_blocks); + spin_lock(&jffs2_compressor_list_lock); + list_for_each_entry(this, &jffs2_compressor_list, list) { + act_buf += sprintf(act_buf,"%10s ",this->name); + if ((this->disabled)||(!this->compress)) + act_buf += sprintf(act_buf,"- "); + else + act_buf += sprintf(act_buf,"+ "); + act_buf += sprintf(act_buf,"compr: %d blocks (%d/%d) decompr: %d blocks ", this->stat_compr_blocks, + this->stat_compr_new_size, this->stat_compr_orig_size, + this->stat_decompr_blocks); + act_buf += sprintf(act_buf,"\n"); + } + spin_unlock(&jffs2_compressor_list_lock); + + return buf; +} + +char *jffs2_get_compression_mode_name(void) +{ + switch (jffs2_compression_mode) { + case JFFS2_COMPR_MODE_NONE: + return "none"; + case JFFS2_COMPR_MODE_PRIORITY: + return "priority"; + case JFFS2_COMPR_MODE_SIZE: + return "size"; + } + return "unkown"; +} + +int jffs2_set_compression_mode_name(const char *name) +{ + if (!strcmp("none",name)) { + jffs2_compression_mode = JFFS2_COMPR_MODE_NONE; + return 0; + } + if (!strcmp("priority",name)) { + jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY; + return 0; + } + if (!strcmp("size",name)) { + jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE; + return 0; + } + return 1; +} + +static int jffs2_compressor_Xable(const char *name, int disabled) +{ + struct jffs2_compressor *this; + spin_lock(&jffs2_compressor_list_lock); + list_for_each_entry(this, &jffs2_compressor_list, list) { + if (!strcmp(this->name, name)) { + this->disabled = disabled; + spin_unlock(&jffs2_compressor_list_lock); + return 0; + } + } + spin_unlock(&jffs2_compressor_list_lock); + printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name); + return 1; +} + +int jffs2_enable_compressor_name(const char *name) +{ + return jffs2_compressor_Xable(name, 0); +} + +int jffs2_disable_compressor_name(const char *name) +{ + return jffs2_compressor_Xable(name, 1); +} + +int jffs2_set_compressor_priority(const char *name, int priority) +{ + struct jffs2_compressor *this,*comp; + spin_lock(&jffs2_compressor_list_lock); + list_for_each_entry(this, &jffs2_compressor_list, list) { + if (!strcmp(this->name, name)) { + this->priority = priority; + comp = this; + goto reinsert; + } + } + spin_unlock(&jffs2_compressor_list_lock); + printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name); + return 1; +reinsert: + /* list is sorted in the order of priority, so if + we change it we have to reinsert it into the + good place */ + list_del(&comp->list); + list_for_each_entry(this, &jffs2_compressor_list, list) { + if (this->priority < comp->priority) { + list_add(&comp->list, this->list.prev); + spin_unlock(&jffs2_compressor_list_lock); + return 0; + } + } + list_add_tail(&comp->list, &jffs2_compressor_list); + spin_unlock(&jffs2_compressor_list_lock); + return 0; +} + +#endif + +void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig) +{ + if (orig != comprbuf) + kfree(comprbuf); +} + +int 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_LZARI + jffs2_lzari_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 + D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");) +#endif +#endif + return 0; +} + +int jffs2_compressors_exit(void) +{ +/* Unregistering compressors */ +#ifdef CONFIG_JFFS2_LZO + jffs2_lzo_exit(); +#endif +#ifdef CONFIG_JFFS2_LZARI + jffs2_lzari_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; +} |