252 lines
6.6 KiB
C
252 lines
6.6 KiB
C
/*
|
|
* This file is part of UBIFS.
|
|
*
|
|
* Copyright (C) 2006-2008 Nokia Corporation.
|
|
* Copyright (C) 2006, 2007 University of Szeged, Hungary
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 as published by
|
|
* the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
|
* more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along with
|
|
* this program; if not, write to the Free Software Foundation, Inc., 51
|
|
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*
|
|
* Authors: Adrian Hunter
|
|
* Artem Bityutskiy (Битюцкий Артём)
|
|
* Zoltan Sogor
|
|
*/
|
|
|
|
/*
|
|
* This file provides a single place to access to compression and
|
|
* decompression.
|
|
*/
|
|
|
|
#include <linux/crypto.h>
|
|
#include "ubifs.h"
|
|
|
|
/* Fake description object for the "none" compressor */
|
|
static struct ubifs_compressor none_compr = {
|
|
.compr_type = UBIFS_COMPR_NONE,
|
|
.name = "no compression",
|
|
.capi_name = "",
|
|
};
|
|
|
|
#ifdef CONFIG_UBIFS_FS_LZO
|
|
static DEFINE_MUTEX(lzo_mutex);
|
|
|
|
static struct ubifs_compressor lzo_compr = {
|
|
.compr_type = UBIFS_COMPR_LZO,
|
|
.comp_mutex = &lzo_mutex,
|
|
.name = "LZO",
|
|
.capi_name = "lzo",
|
|
};
|
|
#else
|
|
static struct ubifs_compressor lzo_compr = {
|
|
.compr_type = UBIFS_COMPR_LZO,
|
|
.name = "LZO",
|
|
};
|
|
#endif
|
|
|
|
#ifdef CONFIG_UBIFS_FS_ZLIB
|
|
static DEFINE_MUTEX(deflate_mutex);
|
|
static DEFINE_MUTEX(inflate_mutex);
|
|
|
|
static struct ubifs_compressor zlib_compr = {
|
|
.compr_type = UBIFS_COMPR_ZLIB,
|
|
.comp_mutex = &deflate_mutex,
|
|
.decomp_mutex = &inflate_mutex,
|
|
.name = "zlib",
|
|
.capi_name = "deflate",
|
|
};
|
|
#else
|
|
static struct ubifs_compressor zlib_compr = {
|
|
.compr_type = UBIFS_COMPR_ZLIB,
|
|
.name = "zlib",
|
|
};
|
|
#endif
|
|
|
|
/* All UBIFS compressors */
|
|
struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];
|
|
|
|
/**
|
|
* ubifs_compress - compress data.
|
|
* @in_buf: data to compress
|
|
* @in_len: length of the data to compress
|
|
* @out_buf: output buffer where compressed data should be stored
|
|
* @out_len: output buffer length is returned here
|
|
* @compr_type: type of compression to use on enter, actually used compression
|
|
* type on exit
|
|
*
|
|
* This function compresses input buffer @in_buf of length @in_len and stores
|
|
* the result in the output buffer @out_buf and the resulting length in
|
|
* @out_len. If the input buffer does not compress, it is just copied to the
|
|
* @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if
|
|
* compression error occurred.
|
|
*
|
|
* Note, if the input buffer was not compressed, it is copied to the output
|
|
* buffer and %UBIFS_COMPR_NONE is returned in @compr_type.
|
|
*/
|
|
void ubifs_compress(const void *in_buf, int in_len, void *out_buf, int *out_len,
|
|
int *compr_type)
|
|
{
|
|
int err;
|
|
struct ubifs_compressor *compr = ubifs_compressors[*compr_type];
|
|
|
|
if (*compr_type == UBIFS_COMPR_NONE)
|
|
goto no_compr;
|
|
|
|
/* If the input data is small, do not even try to compress it */
|
|
if (in_len < UBIFS_MIN_COMPR_LEN)
|
|
goto no_compr;
|
|
|
|
if (compr->comp_mutex)
|
|
mutex_lock(compr->comp_mutex);
|
|
err = crypto_comp_compress(compr->cc, in_buf, in_len, out_buf,
|
|
out_len);
|
|
if (compr->comp_mutex)
|
|
mutex_unlock(compr->comp_mutex);
|
|
if (unlikely(err)) {
|
|
ubifs_warn("cannot compress %d bytes, compressor %s, "
|
|
"error %d, leave data uncompressed",
|
|
in_len, compr->name, err);
|
|
goto no_compr;
|
|
}
|
|
|
|
/*
|
|
* Presently, we just require that compression results in less data,
|
|
* rather than any defined minimum compression ratio or amount.
|
|
*/
|
|
if (ALIGN(*out_len, 8) >= ALIGN(in_len, 8))
|
|
goto no_compr;
|
|
|
|
return;
|
|
|
|
no_compr:
|
|
memcpy(out_buf, in_buf, in_len);
|
|
*out_len = in_len;
|
|
*compr_type = UBIFS_COMPR_NONE;
|
|
}
|
|
|
|
/**
|
|
* ubifs_decompress - decompress data.
|
|
* @in_buf: data to decompress
|
|
* @in_len: length of the data to decompress
|
|
* @out_buf: output buffer where decompressed data should
|
|
* @out_len: output length is returned here
|
|
* @compr_type: type of compression
|
|
*
|
|
* This function decompresses data from buffer @in_buf into buffer @out_buf.
|
|
* The length of the uncompressed data is returned in @out_len. This functions
|
|
* returns %0 on success or a negative error code on failure.
|
|
*/
|
|
int ubifs_decompress(const void *in_buf, int in_len, void *out_buf,
|
|
int *out_len, int compr_type)
|
|
{
|
|
int err;
|
|
struct ubifs_compressor *compr;
|
|
|
|
if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) {
|
|
ubifs_err("invalid compression type %d", compr_type);
|
|
return -EINVAL;
|
|
}
|
|
|
|
compr = ubifs_compressors[compr_type];
|
|
|
|
if (unlikely(!compr->capi_name)) {
|
|
ubifs_err("%s compression is not compiled in", compr->name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (compr_type == UBIFS_COMPR_NONE) {
|
|
memcpy(out_buf, in_buf, in_len);
|
|
*out_len = in_len;
|
|
return 0;
|
|
}
|
|
|
|
if (compr->decomp_mutex)
|
|
mutex_lock(compr->decomp_mutex);
|
|
err = crypto_comp_decompress(compr->cc, in_buf, in_len, out_buf,
|
|
out_len);
|
|
if (compr->decomp_mutex)
|
|
mutex_unlock(compr->decomp_mutex);
|
|
if (err)
|
|
ubifs_err("cannot decompress %d bytes, compressor %s, "
|
|
"error %d", in_len, compr->name, err);
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* compr_init - initialize a compressor.
|
|
* @compr: compressor description object
|
|
*
|
|
* This function initializes the requested compressor and returns zero in case
|
|
* of success or a negative error code in case of failure.
|
|
*/
|
|
static int __init compr_init(struct ubifs_compressor *compr)
|
|
{
|
|
if (compr->capi_name) {
|
|
compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0);
|
|
if (IS_ERR(compr->cc)) {
|
|
ubifs_err("cannot initialize compressor %s, error %ld",
|
|
compr->name, PTR_ERR(compr->cc));
|
|
return PTR_ERR(compr->cc);
|
|
}
|
|
}
|
|
|
|
ubifs_compressors[compr->compr_type] = compr;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* compr_exit - de-initialize a compressor.
|
|
* @compr: compressor description object
|
|
*/
|
|
static void compr_exit(struct ubifs_compressor *compr)
|
|
{
|
|
if (compr->capi_name)
|
|
crypto_free_comp(compr->cc);
|
|
return;
|
|
}
|
|
|
|
/**
|
|
* ubifs_compressors_init - initialize UBIFS compressors.
|
|
*
|
|
* This function initializes the compressor which were compiled in. Returns
|
|
* zero in case of success and a negative error code in case of failure.
|
|
*/
|
|
int __init ubifs_compressors_init(void)
|
|
{
|
|
int err;
|
|
|
|
err = compr_init(&lzo_compr);
|
|
if (err)
|
|
return err;
|
|
|
|
err = compr_init(&zlib_compr);
|
|
if (err)
|
|
goto out_lzo;
|
|
|
|
ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr;
|
|
return 0;
|
|
|
|
out_lzo:
|
|
compr_exit(&lzo_compr);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ubifs_compressors_exit - de-initialize UBIFS compressors.
|
|
*/
|
|
void __exit ubifs_compressors_exit(void)
|
|
{
|
|
compr_exit(&lzo_compr);
|
|
compr_exit(&zlib_compr);
|
|
}
|