| /* | |
| * JFFS2 -- Journalling Flash File System, Version 2. | |
| * | |
| * Copyright © 2001-2007 Red Hat, Inc. | |
| * Created by Arjan van de Ven <arjanv@redhat.com> | |
| * | |
| * Copyright © 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>, | |
| * University of Szeged, Hungary | |
| * | |
| * 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; | |
| /* 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; | |
| } | |
| 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 | |
| /* 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_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; | |
| } |