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 * @c: UBIFS file-system description object
86 * @in_buf: data to compress
87 * @in_len: length of the data to compress
88 * @out_buf: output buffer where compressed data should be stored
89 * @out_len: output buffer length is returned here
90 * @compr_type: type of compression to use on enter, actually used compression
91 * type on exit
92 *
93 * This function compresses input buffer @in_buf of length @in_len and stores
94 * the result in the output buffer @out_buf and the resulting length in
95 * @out_len. If the input buffer does not compress, it is just copied to the
96 * @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if
97 * compression error occurred.
98 *
99 * Note, if the input buffer was not compressed, it is copied to the output
100 * buffer and %UBIFS_COMPR_NONE is returned in @compr_type.
101 */
102 void 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 it
129 * uncompressed to improve read speed.
130 */
131 if (in_len - *out_len < UBIFS_MIN_COMPRESS_DIFF)
132 goto no_compr;
133
134 return;
135
136 no_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 object
145 * @in_buf: data to decompress
146 * @in_len: length of the data to decompress
147 * @out_buf: output buffer where decompressed data should
148 * @out_len: output length is returned here
149 * @compr_type: type of compression
150 *
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 functions
153 * returns %0 on success or a negative error code on failure.
154 */
155 int 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 object
195 *
196 * This function initializes the requested compressor and returns zero in case
197 * of success or a negative error code in case of failure.
198 */
199 static 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 object
217 */
218 static 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. Returns
228 * zero in case of success and a negative error code in case of failure.
229 */
230 int __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
249 out_zstd:
250 compr_exit(&zstd_compr);
251 out_lzo:
252 compr_exit(&lzo_compr);
253 return err;
254 }
255
256 /**
257 * ubifs_compressors_exit - de-initialize UBIFS compressors.
258 */
259 void ubifs_compressors_exit(void)
260 {
261 compr_exit(&lzo_compr);
262 compr_exit(&zlib_compr);
263 compr_exit(&zstd_compr);
264 }
265
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