Commit | Line | Data |
---|---|---|
1e51764a AB |
1 | /* |
2 | * This file is part of UBIFS. | |
3 | * | |
4 | * Copyright (C) 2006-2008 Nokia Corporation. | |
5 | * Copyright (C) 2006, 2007 University of Szeged, Hungary | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License version 2 as published by | |
9 | * the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
14 | * more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License along with | |
17 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
18 | * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
19 | * | |
20 | * Authors: Adrian Hunter | |
21 | * Artem Bityutskiy (Битюцкий Артём) | |
22 | * Zoltan Sogor | |
23 | */ | |
24 | ||
25 | /* | |
26 | * This file provides a single place to access to compression and | |
27 | * decompression. | |
28 | */ | |
29 | ||
30 | #include <linux/crypto.h> | |
31 | #include "ubifs.h" | |
32 | ||
33 | /* Fake description object for the "none" compressor */ | |
34 | static struct ubifs_compressor none_compr = { | |
35 | .compr_type = UBIFS_COMPR_NONE, | |
553dea4d | 36 | .name = "none", |
1e51764a AB |
37 | .capi_name = "", |
38 | }; | |
39 | ||
40 | #ifdef CONFIG_UBIFS_FS_LZO | |
41 | static DEFINE_MUTEX(lzo_mutex); | |
42 | ||
43 | static struct ubifs_compressor lzo_compr = { | |
44 | .compr_type = UBIFS_COMPR_LZO, | |
45 | .comp_mutex = &lzo_mutex, | |
553dea4d | 46 | .name = "lzo", |
1e51764a AB |
47 | .capi_name = "lzo", |
48 | }; | |
49 | #else | |
50 | static struct ubifs_compressor lzo_compr = { | |
51 | .compr_type = UBIFS_COMPR_LZO, | |
553dea4d | 52 | .name = "lzo", |
1e51764a AB |
53 | }; |
54 | #endif | |
55 | ||
56 | #ifdef CONFIG_UBIFS_FS_ZLIB | |
57 | static DEFINE_MUTEX(deflate_mutex); | |
58 | static DEFINE_MUTEX(inflate_mutex); | |
59 | ||
60 | static struct ubifs_compressor zlib_compr = { | |
61 | .compr_type = UBIFS_COMPR_ZLIB, | |
62 | .comp_mutex = &deflate_mutex, | |
63 | .decomp_mutex = &inflate_mutex, | |
64 | .name = "zlib", | |
65 | .capi_name = "deflate", | |
66 | }; | |
67 | #else | |
68 | static struct ubifs_compressor zlib_compr = { | |
69 | .compr_type = UBIFS_COMPR_ZLIB, | |
70 | .name = "zlib", | |
71 | }; | |
72 | #endif | |
73 | ||
74 | /* All UBIFS compressors */ | |
75 | struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT]; | |
76 | ||
77 | /** | |
78 | * ubifs_compress - compress data. | |
79 | * @in_buf: data to compress | |
80 | * @in_len: length of the data to compress | |
81 | * @out_buf: output buffer where compressed data should be stored | |
82 | * @out_len: output buffer length is returned here | |
83 | * @compr_type: type of compression to use on enter, actually used compression | |
84 | * type on exit | |
85 | * | |
86 | * This function compresses input buffer @in_buf of length @in_len and stores | |
87 | * the result in the output buffer @out_buf and the resulting length in | |
88 | * @out_len. If the input buffer does not compress, it is just copied to the | |
89 | * @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if | |
90 | * compression error occurred. | |
91 | * | |
92 | * Note, if the input buffer was not compressed, it is copied to the output | |
93 | * buffer and %UBIFS_COMPR_NONE is returned in @compr_type. | |
1e51764a AB |
94 | */ |
95 | void ubifs_compress(const void *in_buf, int in_len, void *out_buf, int *out_len, | |
96 | int *compr_type) | |
97 | { | |
98 | int err; | |
99 | struct ubifs_compressor *compr = ubifs_compressors[*compr_type]; | |
100 | ||
101 | if (*compr_type == UBIFS_COMPR_NONE) | |
102 | goto no_compr; | |
103 | ||
104 | /* If the input data is small, do not even try to compress it */ | |
105 | if (in_len < UBIFS_MIN_COMPR_LEN) | |
106 | goto no_compr; | |
107 | ||
108 | if (compr->comp_mutex) | |
109 | mutex_lock(compr->comp_mutex); | |
110 | err = crypto_comp_compress(compr->cc, in_buf, in_len, out_buf, | |
6a4a9b43 | 111 | (unsigned int *)out_len); |
1e51764a AB |
112 | if (compr->comp_mutex) |
113 | mutex_unlock(compr->comp_mutex); | |
114 | if (unlikely(err)) { | |
115 | ubifs_warn("cannot compress %d bytes, compressor %s, " | |
116 | "error %d, leave data uncompressed", | |
117 | in_len, compr->name, err); | |
118 | goto no_compr; | |
119 | } | |
120 | ||
121 | /* | |
062e4fee AB |
122 | * If the data compressed only slightly, it is better to leave it |
123 | * uncompressed to improve read speed. | |
1e51764a | 124 | */ |
062e4fee | 125 | if (in_len - *out_len < UBIFS_MIN_COMPRESS_DIFF) |
1e51764a AB |
126 | goto no_compr; |
127 | ||
128 | return; | |
129 | ||
130 | no_compr: | |
131 | memcpy(out_buf, in_buf, in_len); | |
132 | *out_len = in_len; | |
133 | *compr_type = UBIFS_COMPR_NONE; | |
134 | } | |
135 | ||
136 | /** | |
137 | * ubifs_decompress - decompress data. | |
138 | * @in_buf: data to decompress | |
139 | * @in_len: length of the data to decompress | |
140 | * @out_buf: output buffer where decompressed data should | |
141 | * @out_len: output length is returned here | |
142 | * @compr_type: type of compression | |
143 | * | |
144 | * This function decompresses data from buffer @in_buf into buffer @out_buf. | |
145 | * The length of the uncompressed data is returned in @out_len. This functions | |
146 | * returns %0 on success or a negative error code on failure. | |
147 | */ | |
148 | int ubifs_decompress(const void *in_buf, int in_len, void *out_buf, | |
149 | int *out_len, int compr_type) | |
150 | { | |
151 | int err; | |
152 | struct ubifs_compressor *compr; | |
153 | ||
154 | if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) { | |
155 | ubifs_err("invalid compression type %d", compr_type); | |
156 | return -EINVAL; | |
157 | } | |
158 | ||
159 | compr = ubifs_compressors[compr_type]; | |
160 | ||
161 | if (unlikely(!compr->capi_name)) { | |
162 | ubifs_err("%s compression is not compiled in", compr->name); | |
163 | return -EINVAL; | |
164 | } | |
165 | ||
166 | if (compr_type == UBIFS_COMPR_NONE) { | |
167 | memcpy(out_buf, in_buf, in_len); | |
168 | *out_len = in_len; | |
169 | return 0; | |
170 | } | |
171 | ||
172 | if (compr->decomp_mutex) | |
173 | mutex_lock(compr->decomp_mutex); | |
174 | err = crypto_comp_decompress(compr->cc, in_buf, in_len, out_buf, | |
6a4a9b43 | 175 | (unsigned int *)out_len); |
1e51764a AB |
176 | if (compr->decomp_mutex) |
177 | mutex_unlock(compr->decomp_mutex); | |
178 | if (err) | |
179 | ubifs_err("cannot decompress %d bytes, compressor %s, " | |
180 | "error %d", in_len, compr->name, err); | |
181 | ||
182 | return err; | |
183 | } | |
184 | ||
185 | /** | |
186 | * compr_init - initialize a compressor. | |
187 | * @compr: compressor description object | |
188 | * | |
189 | * This function initializes the requested compressor and returns zero in case | |
190 | * of success or a negative error code in case of failure. | |
191 | */ | |
192 | static int __init compr_init(struct ubifs_compressor *compr) | |
193 | { | |
194 | if (compr->capi_name) { | |
195 | compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0); | |
196 | if (IS_ERR(compr->cc)) { | |
197 | ubifs_err("cannot initialize compressor %s, error %ld", | |
198 | compr->name, PTR_ERR(compr->cc)); | |
199 | return PTR_ERR(compr->cc); | |
200 | } | |
201 | } | |
202 | ||
203 | ubifs_compressors[compr->compr_type] = compr; | |
204 | return 0; | |
205 | } | |
206 | ||
207 | /** | |
208 | * compr_exit - de-initialize a compressor. | |
209 | * @compr: compressor description object | |
210 | */ | |
211 | static void compr_exit(struct ubifs_compressor *compr) | |
212 | { | |
213 | if (compr->capi_name) | |
214 | crypto_free_comp(compr->cc); | |
215 | return; | |
216 | } | |
217 | ||
218 | /** | |
219 | * ubifs_compressors_init - initialize UBIFS compressors. | |
220 | * | |
221 | * This function initializes the compressor which were compiled in. Returns | |
222 | * zero in case of success and a negative error code in case of failure. | |
223 | */ | |
224 | int __init ubifs_compressors_init(void) | |
225 | { | |
226 | int err; | |
227 | ||
228 | err = compr_init(&lzo_compr); | |
229 | if (err) | |
230 | return err; | |
231 | ||
232 | err = compr_init(&zlib_compr); | |
233 | if (err) | |
234 | goto out_lzo; | |
235 | ||
236 | ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr; | |
237 | return 0; | |
238 | ||
239 | out_lzo: | |
240 | compr_exit(&lzo_compr); | |
241 | return err; | |
242 | } | |
243 | ||
244 | /** | |
245 | * ubifs_compressors_exit - de-initialize UBIFS compressors. | |
246 | */ | |
995be045 | 247 | void ubifs_compressors_exit(void) |
1e51764a AB |
248 | { |
249 | compr_exit(&lzo_compr); | |
250 | compr_exit(&zlib_compr); | |
251 | } |