1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * This file is part of UBIFS. 4 * 5 * Copyright (C) 2006-2008 Nokia Corporation. 6 * Copyright (C) 2006, 2007 University of Szeged, Hungary 7 * 8 * Authors: Adrian Hunter 9 * Artem Bityutskiy (Битюцкий Артём) 10 * Zoltan Sogor 11 */ 12 13 /* 14 * This file provides a single place to access to compression and 15 * decompression. 16 */ 17 18 #include <linux/crypto.h> 19 #include "ubifs.h" 20 21 /* Fake description object for the "none" compressor */ 22 static struct ubifs_compressor none_compr = { 23 .compr_type = UBIFS_COMPR_NONE, 24 .name = "none", 25 .capi_name = "", 26 }; 27 28 #ifdef CONFIG_UBIFS_FS_LZO 29 static DEFINE_MUTEX(lzo_mutex); 30 31 static 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 #else 38 static struct ubifs_compressor lzo_compr = { 39 .compr_type = UBIFS_COMPR_LZO, 40 .name = "lzo", 41 }; 42 #endif 43 44 #ifdef CONFIG_UBIFS_FS_ZLIB 45 static DEFINE_MUTEX(deflate_mutex); 46 static DEFINE_MUTEX(inflate_mutex); 47 48 static 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 #else 56 static struct ubifs_compressor zlib_compr = { 57 .compr_type = UBIFS_COMPR_ZLIB, 58 .name = "zlib", 59 }; 60 #endif 61 62 #ifdef CONFIG_UBIFS_FS_ZSTD 63 static DEFINE_MUTEX(zstd_enc_mutex); 64 static DEFINE_MUTEX(zstd_dec_mutex); 65 66 static 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 #else 74 static struct ubifs_compressor zstd_compr = { 75 .compr_type = UBIFS_COMPR_ZSTD, 76 .name = "zstd", 77 }; 78 #endif 79 80 /* All UBIFS compressors */ 81 struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT]; 82 83 /** 84 * ubifs_compress - compress data. 85 * @in_buf: data to compress 86 * @in_len: length of the data to compress 87 * @out_buf: output buffer where compressed data should be stored 88 * @out_len: output buffer length is returned here 89 * @compr_type: type of compression to use on enter, actually used compression 90 * type on exit 91 * 92 * This function compresses input buffer @in_buf of length @in_len and stores 93 * the result in the output buffer @out_buf and the resulting length in 94 * @out_len. If the input buffer does not compress, it is just copied to the 95 * @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if 96 * compression error occurred. 97 * 98 * Note, if the input buffer was not compressed, it is copied to the output 99 * buffer and %UBIFS_COMPR_NONE is returned in @compr_type. 100 */ 101 void ubifs_compress(const struct ubifs_info *c, const void *in_buf, 102 int in_len, void *out_buf, int *out_len, int *compr_type) 103 { 104 int err; 105 struct ubifs_compressor *compr = ubifs_compressors[*compr_type]; 106 107 if (*compr_type == UBIFS_COMPR_NONE) 108 goto no_compr; 109 110 /* If the input data is small, do not even try to compress it */ 111 if (in_len < UBIFS_MIN_COMPR_LEN) 112 goto no_compr; 113 114 if (compr->comp_mutex) 115 mutex_lock(compr->comp_mutex); 116 err = crypto_comp_compress(compr->cc, in_buf, in_len, out_buf, 117 (unsigned int *)out_len); 118 if (compr->comp_mutex) 119 mutex_unlock(compr->comp_mutex); 120 if (unlikely(err)) { 121 ubifs_warn(c, "cannot compress %d bytes, compressor %s, error %d, leave data uncompressed", 122 in_len, compr->name, err); 123 goto no_compr; 124 } 125 126 /* 127 * If the data compressed only slightly, it is better to leave it 128 * uncompressed to improve read speed. 129 */ 130 if (in_len - *out_len < UBIFS_MIN_COMPRESS_DIFF) 131 goto no_compr; 132 133 return; 134 135 no_compr: 136 memcpy(out_buf, in_buf, in_len); 137 *out_len = in_len; 138 *compr_type = UBIFS_COMPR_NONE; 139 } 140 141 /** 142 * ubifs_decompress - decompress data. 143 * @in_buf: data to decompress 144 * @in_len: length of the data to decompress 145 * @out_buf: output buffer where decompressed data should 146 * @out_len: output length is returned here 147 * @compr_type: type of compression 148 * 149 * This function decompresses data from buffer @in_buf into buffer @out_buf. 150 * The length of the uncompressed data is returned in @out_len. This functions 151 * returns %0 on success or a negative error code on failure. 152 */ 153 int ubifs_decompress(const struct ubifs_info *c, const void *in_buf, 154 int in_len, void *out_buf, int *out_len, int compr_type) 155 { 156 int err; 157 struct ubifs_compressor *compr; 158 159 if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) { 160 ubifs_err(c, "invalid compression type %d", compr_type); 161 return -EINVAL; 162 } 163 164 compr = ubifs_compressors[compr_type]; 165 166 if (unlikely(!compr->capi_name)) { 167 ubifs_err(c, "%s compression is not compiled in", compr->name); 168 return -EINVAL; 169 } 170 171 if (compr_type == UBIFS_COMPR_NONE) { 172 memcpy(out_buf, in_buf, in_len); 173 *out_len = in_len; 174 return 0; 175 } 176 177 if (compr->decomp_mutex) 178 mutex_lock(compr->decomp_mutex); 179 err = crypto_comp_decompress(compr->cc, in_buf, in_len, out_buf, 180 (unsigned int *)out_len); 181 if (compr->decomp_mutex) 182 mutex_unlock(compr->decomp_mutex); 183 if (err) 184 ubifs_err(c, "cannot decompress %d bytes, compressor %s, error %d", 185 in_len, compr->name, err); 186 187 return err; 188 } 189 190 /** 191 * compr_init - initialize a compressor. 192 * @compr: compressor description object 193 * 194 * This function initializes the requested compressor and returns zero in case 195 * of success or a negative error code in case of failure. 196 */ 197 static int __init compr_init(struct ubifs_compressor *compr) 198 { 199 if (compr->capi_name) { 200 compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0); 201 if (IS_ERR(compr->cc)) { 202 pr_err("UBIFS error (pid %d): cannot initialize compressor %s, error %ld", 203 current->pid, compr->name, PTR_ERR(compr->cc)); 204 return PTR_ERR(compr->cc); 205 } 206 } 207 208 ubifs_compressors[compr->compr_type] = compr; 209 return 0; 210 } 211 212 /** 213 * compr_exit - de-initialize a compressor. 214 * @compr: compressor description object 215 */ 216 static void compr_exit(struct ubifs_compressor *compr) 217 { 218 if (compr->capi_name) 219 crypto_free_comp(compr->cc); 220 } 221 222 /** 223 * ubifs_compressors_init - initialize UBIFS compressors. 224 * 225 * This function initializes the compressor which were compiled in. Returns 226 * zero in case of success and a negative error code in case of failure. 227 */ 228 int __init ubifs_compressors_init(void) 229 { 230 int err; 231 232 err = compr_init(&lzo_compr); 233 if (err) 234 return err; 235 236 err = compr_init(&zstd_compr); 237 if (err) 238 goto out_lzo; 239 240 err = compr_init(&zlib_compr); 241 if (err) 242 goto out_zstd; 243 244 ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr; 245 return 0; 246 247 out_zstd: 248 compr_exit(&zstd_compr); 249 out_lzo: 250 compr_exit(&lzo_compr); 251 return err; 252 } 253 254 /** 255 * ubifs_compressors_exit - de-initialize UBIFS compressors. 256 */ 257 void ubifs_compressors_exit(void) 258 { 259 compr_exit(&lzo_compr); 260 compr_exit(&zlib_compr); 261 compr_exit(&zstd_compr); 262 } 263