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 */
ubifs_compress(const struct ubifs_info * c,const void * in_buf,int in_len,void * out_buf,int * out_len,int * compr_type)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 */
ubifs_decompress(const struct ubifs_info * c,const void * in_buf,int in_len,void * out_buf,int * out_len,int compr_type)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 */
compr_init(struct ubifs_compressor * compr)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 */
compr_exit(struct ubifs_compressor * compr)216 static void compr_exit(struct ubifs_compressor *compr)
217 {
218 if (compr->capi_name)
219 crypto_free_comp(compr->cc);
220 return;
221 }
222
223 /**
224 * ubifs_compressors_init - initialize UBIFS compressors.
225 *
226 * This function initializes the compressor which were compiled in. Returns
227 * zero in case of success and a negative error code in case of failure.
228 */
ubifs_compressors_init(void)229 int __init ubifs_compressors_init(void)
230 {
231 int err;
232
233 err = compr_init(&lzo_compr);
234 if (err)
235 return err;
236
237 err = compr_init(&zstd_compr);
238 if (err)
239 goto out_lzo;
240
241 err = compr_init(&zlib_compr);
242 if (err)
243 goto out_zstd;
244
245 ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr;
246 return 0;
247
248 out_zstd:
249 compr_exit(&zstd_compr);
250 out_lzo:
251 compr_exit(&lzo_compr);
252 return err;
253 }
254
255 /**
256 * ubifs_compressors_exit - de-initialize UBIFS compressors.
257 */
ubifs_compressors_exit(void)258 void ubifs_compressors_exit(void)
259 {
260 compr_exit(&lzo_compr);
261 compr_exit(&zlib_compr);
262 compr_exit(&zstd_compr);
263 }
264