| /* |
| * 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_selected_compress: |
| * @compr: Explicit compression type to use (ie, JFFS2_COMPR_ZLIB). |
| * If 0, just take the first available compression mode. |
| * @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: the compression type used. Zero is used to show that the data |
| * could not be compressed; probably because we couldn't find the requested |
| * compression mode. |
| */ |
| static int jffs2_selected_compress(u8 compr, unsigned char *data_in, |
| unsigned char **cpage_out, u32 *datalen, u32 *cdatalen) |
| { |
| struct jffs2_compressor *this; |
| int err, ret = JFFS2_COMPR_NONE; |
| uint32_t orig_slen, orig_dlen; |
| char *output_buf; |
| |
| output_buf = kmalloc(*cdatalen, GFP_KERNEL); |
| if (!output_buf) { |
| printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n"); |
| return ret; |
| } |
| orig_slen = *datalen; |
| orig_dlen = *cdatalen; |
| spin_lock(&jffs2_compressor_list_lock); |
| list_for_each_entry(this, &jffs2_compressor_list, list) { |
| /* Skip decompress-only and disabled modules */ |
| if (!this->compress || this->disabled) |
| continue; |
| |
| /* Skip if not the desired compression type */ |
| if (compr && (compr != this->compr)) |
| continue; |
| |
| /* |
| * Either compression type was unspecified, or we found our |
| * compressor; either way, we're good to go. |
| */ |
| this->usecount++; |
| spin_unlock(&jffs2_compressor_list_lock); |
| |
| *datalen = orig_slen; |
| *cdatalen = orig_dlen; |
| err = this->compress(data_in, output_buf, datalen, cdatalen); |
| |
| spin_lock(&jffs2_compressor_list_lock); |
| this->usecount--; |
| if (!err) { |
| /* Success */ |
| 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); |
| else |
| *cpage_out = output_buf; |
| |
| return ret; |
| } |
| |
| /* 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 mode, 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; |
| |
| if (c->mount_opts.override_compr) |
| mode = c->mount_opts.compr; |
| else |
| mode = jffs2_compression_mode; |
| |
| switch (mode) { |
| case JFFS2_COMPR_MODE_NONE: |
| break; |
| case JFFS2_COMPR_MODE_PRIORITY: |
| ret = jffs2_selected_compress(0, data_in, cpage_out, datalen, |
| cdatalen); |
| 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; |
| *cpage_out = output_buf; |
| } |
| spin_unlock(&jffs2_compressor_list_lock); |
| break; |
| case JFFS2_COMPR_MODE_FORCELZO: |
| ret = jffs2_selected_compress(JFFS2_COMPR_LZO, data_in, |
| cpage_out, datalen, cdatalen); |
| break; |
| case JFFS2_COMPR_MODE_FORCEZLIB: |
| ret = jffs2_selected_compress(JFFS2_COMPR_ZLIB, data_in, |
| cpage_out, datalen, cdatalen); |
| break; |
| default: |
| printk(KERN_ERR "JFFS2: unknown compression mode.\n"); |
| } |
| |
| if (ret == JFFS2_COMPR_NONE) { |
| *cpage_out = data_in; |
| *datalen = *cdatalen; |
| none_stat_compr_blocks++; |
| none_stat_compr_size += *datalen; |
| } |
| 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; |
| jffs2_dbg(1, "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); |
| |
| jffs2_dbg(1, "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 module 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; |
| jffs2_dbg(1, "JFFS2: default compression mode: none\n"); |
| #else |
| #ifdef CONFIG_JFFS2_CMODE_SIZE |
| jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE; |
| jffs2_dbg(1, "JFFS2: default compression mode: size\n"); |
| #else |
| #ifdef CONFIG_JFFS2_CMODE_FAVOURLZO |
| jffs2_compression_mode = JFFS2_COMPR_MODE_FAVOURLZO; |
| jffs2_dbg(1, "JFFS2: default compression mode: favourlzo\n"); |
| #else |
| jffs2_dbg(1, "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; |
| } |