265 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * This file is part of UBIFS.4 *5 * Copyright (C) 2006-2008 Nokia Corporation.6 * Copyright (C) 2006, 2007 University of Szeged, Hungary7 *8 * Authors: Adrian Hunter9 * Artem Bityutskiy (Битюцкий Артём)10 * Zoltan Sogor11 */12 13/*14 * This file provides a single place to access to compression and15 * decompression.16 */17 18#include <linux/crypto.h>19#include "ubifs.h"20 21/* Fake description object for the "none" compressor */22static struct ubifs_compressor none_compr = {23 .compr_type = UBIFS_COMPR_NONE,24 .name = "none",25 .capi_name = "",26};27 28#ifdef CONFIG_UBIFS_FS_LZO29static DEFINE_MUTEX(lzo_mutex);30 31static struct ubifs_compressor lzo_compr = {32 .compr_type = UBIFS_COMPR_LZO,33 .comp_mutex = &lzo_mutex,34 .name = "lzo",35 .capi_name = "lzo",36};37#else38static struct ubifs_compressor lzo_compr = {39 .compr_type = UBIFS_COMPR_LZO,40 .name = "lzo",41};42#endif43 44#ifdef CONFIG_UBIFS_FS_ZLIB45static DEFINE_MUTEX(deflate_mutex);46static DEFINE_MUTEX(inflate_mutex);47 48static struct ubifs_compressor zlib_compr = {49 .compr_type = UBIFS_COMPR_ZLIB,50 .comp_mutex = &deflate_mutex,51 .decomp_mutex = &inflate_mutex,52 .name = "zlib",53 .capi_name = "deflate",54};55#else56static struct ubifs_compressor zlib_compr = {57 .compr_type = UBIFS_COMPR_ZLIB,58 .name = "zlib",59};60#endif61 62#ifdef CONFIG_UBIFS_FS_ZSTD63static DEFINE_MUTEX(zstd_enc_mutex);64static DEFINE_MUTEX(zstd_dec_mutex);65 66static struct ubifs_compressor zstd_compr = {67 .compr_type = UBIFS_COMPR_ZSTD,68 .comp_mutex = &zstd_enc_mutex,69 .decomp_mutex = &zstd_dec_mutex,70 .name = "zstd",71 .capi_name = "zstd",72};73#else74static struct ubifs_compressor zstd_compr = {75 .compr_type = UBIFS_COMPR_ZSTD,76 .name = "zstd",77};78#endif79 80/* All UBIFS compressors */81struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];82 83/**84 * ubifs_compress - compress data.85 * @c: UBIFS file-system description object86 * @in_buf: data to compress87 * @in_len: length of the data to compress88 * @out_buf: output buffer where compressed data should be stored89 * @out_len: output buffer length is returned here90 * @compr_type: type of compression to use on enter, actually used compression91 * type on exit92 *93 * This function compresses input buffer @in_buf of length @in_len and stores94 * the result in the output buffer @out_buf and the resulting length in95 * @out_len. If the input buffer does not compress, it is just copied to the96 * @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if97 * compression error occurred.98 *99 * Note, if the input buffer was not compressed, it is copied to the output100 * buffer and %UBIFS_COMPR_NONE is returned in @compr_type.101 */102void ubifs_compress(const struct ubifs_info *c, const void *in_buf,103 int in_len, void *out_buf, int *out_len, int *compr_type)104{105 int err;106 struct ubifs_compressor *compr = ubifs_compressors[*compr_type];107 108 if (*compr_type == UBIFS_COMPR_NONE)109 goto no_compr;110 111 /* If the input data is small, do not even try to compress it */112 if (in_len < UBIFS_MIN_COMPR_LEN)113 goto no_compr;114 115 if (compr->comp_mutex)116 mutex_lock(compr->comp_mutex);117 err = crypto_comp_compress(compr->cc, in_buf, in_len, out_buf,118 (unsigned int *)out_len);119 if (compr->comp_mutex)120 mutex_unlock(compr->comp_mutex);121 if (unlikely(err)) {122 ubifs_warn(c, "cannot compress %d bytes, compressor %s, error %d, leave data uncompressed",123 in_len, compr->name, err);124 goto no_compr;125 }126 127 /*128 * If the data compressed only slightly, it is better to leave it129 * uncompressed to improve read speed.130 */131 if (in_len - *out_len < UBIFS_MIN_COMPRESS_DIFF)132 goto no_compr;133 134 return;135 136no_compr:137 memcpy(out_buf, in_buf, in_len);138 *out_len = in_len;139 *compr_type = UBIFS_COMPR_NONE;140}141 142/**143 * ubifs_decompress - decompress data.144 * @c: UBIFS file-system description object145 * @in_buf: data to decompress146 * @in_len: length of the data to decompress147 * @out_buf: output buffer where decompressed data should148 * @out_len: output length is returned here149 * @compr_type: type of compression150 *151 * This function decompresses data from buffer @in_buf into buffer @out_buf.152 * The length of the uncompressed data is returned in @out_len. This functions153 * returns %0 on success or a negative error code on failure.154 */155int ubifs_decompress(const struct ubifs_info *c, const void *in_buf,156 int in_len, void *out_buf, int *out_len, int compr_type)157{158 int err;159 struct ubifs_compressor *compr;160 161 if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) {162 ubifs_err(c, "invalid compression type %d", compr_type);163 return -EINVAL;164 }165 166 compr = ubifs_compressors[compr_type];167 168 if (unlikely(!compr->capi_name)) {169 ubifs_err(c, "%s compression is not compiled in", compr->name);170 return -EINVAL;171 }172 173 if (compr_type == UBIFS_COMPR_NONE) {174 memcpy(out_buf, in_buf, in_len);175 *out_len = in_len;176 return 0;177 }178 179 if (compr->decomp_mutex)180 mutex_lock(compr->decomp_mutex);181 err = crypto_comp_decompress(compr->cc, in_buf, in_len, out_buf,182 (unsigned int *)out_len);183 if (compr->decomp_mutex)184 mutex_unlock(compr->decomp_mutex);185 if (err)186 ubifs_err(c, "cannot decompress %d bytes, compressor %s, error %d",187 in_len, compr->name, err);188 189 return err;190}191 192/**193 * compr_init - initialize a compressor.194 * @compr: compressor description object195 *196 * This function initializes the requested compressor and returns zero in case197 * of success or a negative error code in case of failure.198 */199static int __init compr_init(struct ubifs_compressor *compr)200{201 if (compr->capi_name) {202 compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0);203 if (IS_ERR(compr->cc)) {204 pr_err("UBIFS error (pid %d): cannot initialize compressor %s, error %ld",205 current->pid, compr->name, PTR_ERR(compr->cc));206 return PTR_ERR(compr->cc);207 }208 }209 210 ubifs_compressors[compr->compr_type] = compr;211 return 0;212}213 214/**215 * compr_exit - de-initialize a compressor.216 * @compr: compressor description object217 */218static void compr_exit(struct ubifs_compressor *compr)219{220 if (compr->capi_name)221 crypto_free_comp(compr->cc);222}223 224/**225 * ubifs_compressors_init - initialize UBIFS compressors.226 *227 * This function initializes the compressor which were compiled in. Returns228 * zero in case of success and a negative error code in case of failure.229 */230int __init ubifs_compressors_init(void)231{232 int err;233 234 err = compr_init(&lzo_compr);235 if (err)236 return err;237 238 err = compr_init(&zstd_compr);239 if (err)240 goto out_lzo;241 242 err = compr_init(&zlib_compr);243 if (err)244 goto out_zstd;245 246 ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr;247 return 0;248 249out_zstd:250 compr_exit(&zstd_compr);251out_lzo:252 compr_exit(&lzo_compr);253 return err;254}255 256/**257 * ubifs_compressors_exit - de-initialize UBIFS compressors.258 */259void ubifs_compressors_exit(void)260{261 compr_exit(&lzo_compr);262 compr_exit(&zlib_compr);263 compr_exit(&zstd_compr);264}265