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(tfm: compr->cc, src: in_buf, slen: in_len, dst: out_buf, |
117 | dlen: (unsigned int *)out_len); |
118 | if (compr->comp_mutex) |
119 | mutex_unlock(lock: compr->comp_mutex); |
120 | if (unlikely(err)) { |
121 | ubifs_warn(c, fmt: "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, fmt: "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, fmt: "%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(tfm: compr->cc, src: in_buf, slen: in_len, dst: out_buf, |
180 | dlen: (unsigned int *)out_len); |
181 | if (compr->decomp_mutex) |
182 | mutex_unlock(lock: compr->decomp_mutex); |
183 | if (err) |
184 | ubifs_err(c, fmt: "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(alg_name: compr->capi_name, type: 0, mask: 0); |
201 | if (IS_ERR(ptr: 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(ptr: 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(tfm: 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(compr: &lzo_compr); |
233 | if (err) |
234 | return err; |
235 | |
236 | err = compr_init(compr: &zstd_compr); |
237 | if (err) |
238 | goto out_lzo; |
239 | |
240 | err = compr_init(compr: &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(compr: &zstd_compr); |
249 | out_lzo: |
250 | compr_exit(compr: &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(compr: &lzo_compr); |
260 | compr_exit(compr: &zlib_compr); |
261 | compr_exit(compr: &zstd_compr); |
262 | } |
263 | |