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1da177e4 LT |
1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
3 | * | |
c00c310e | 4 | * Copyright © 2001-2007 Red Hat, Inc. |
1da177e4 LT |
5 | * Created by Arjan van de Ven <[email protected]> |
6 | * | |
c00c310e | 7 | * Copyright © 2004 Ferenc Havasi <[email protected]>, |
1da177e4 LT |
8 | * University of Szeged, Hungary |
9 | * | |
10 | * For licensing information, see the file 'LICENCE' in this directory. | |
11 | * | |
1da177e4 LT |
12 | */ |
13 | ||
14 | #include "compr.h" | |
15 | ||
16 | static DEFINE_SPINLOCK(jffs2_compressor_list_lock); | |
17 | ||
18 | /* Available compressors are on this list */ | |
19 | static LIST_HEAD(jffs2_compressor_list); | |
20 | ||
21 | /* Actual compression mode */ | |
22 | static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY; | |
23 | ||
24 | /* Statistics for blocks stored without compression */ | |
25 | static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0; | |
26 | ||
27 | /* jffs2_compress: | |
28 | * @data: Pointer to uncompressed data | |
29 | * @cdata: Pointer to returned pointer to buffer for compressed data | |
30 | * @datalen: On entry, holds the amount of data available for compression. | |
31 | * On exit, expected to hold the amount of data actually compressed. | |
32 | * @cdatalen: On entry, holds the amount of space available for compressed | |
33 | * data. On exit, expected to hold the actual size of the compressed | |
34 | * data. | |
35 | * | |
36 | * Returns: Lower byte to be stored with data indicating compression type used. | |
182ec4ee | 37 | * Zero is used to show that the data could not be compressed - the |
1da177e4 LT |
38 | * compressed version was actually larger than the original. |
39 | * Upper byte will be used later. (soon) | |
40 | * | |
41 | * If the cdata buffer isn't large enough to hold all the uncompressed data, | |
182ec4ee | 42 | * jffs2_compress should compress as much as will fit, and should set |
1da177e4 LT |
43 | * *datalen accordingly to show the amount of data which were compressed. |
44 | */ | |
45 | uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f, | |
182ec4ee | 46 | unsigned char *data_in, unsigned char **cpage_out, |
1da177e4 LT |
47 | uint32_t *datalen, uint32_t *cdatalen) |
48 | { | |
49 | int ret = JFFS2_COMPR_NONE; | |
50 | int compr_ret; | |
51 | struct jffs2_compressor *this, *best=NULL; | |
52 | unsigned char *output_buf = NULL, *tmp_buf; | |
53 | uint32_t orig_slen, orig_dlen; | |
54 | uint32_t best_slen=0, best_dlen=0; | |
55 | ||
56 | switch (jffs2_compression_mode) { | |
57 | case JFFS2_COMPR_MODE_NONE: | |
58 | break; | |
59 | case JFFS2_COMPR_MODE_PRIORITY: | |
60 | output_buf = kmalloc(*cdatalen,GFP_KERNEL); | |
61 | if (!output_buf) { | |
62 | printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n"); | |
63 | goto out; | |
64 | } | |
65 | orig_slen = *datalen; | |
66 | orig_dlen = *cdatalen; | |
67 | spin_lock(&jffs2_compressor_list_lock); | |
68 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
69 | /* Skip decompress-only backwards-compatibility and disabled modules */ | |
70 | if ((!this->compress)||(this->disabled)) | |
71 | continue; | |
72 | ||
73 | this->usecount++; | |
74 | spin_unlock(&jffs2_compressor_list_lock); | |
75 | *datalen = orig_slen; | |
76 | *cdatalen = orig_dlen; | |
77 | compr_ret = this->compress(data_in, output_buf, datalen, cdatalen, NULL); | |
78 | spin_lock(&jffs2_compressor_list_lock); | |
79 | this->usecount--; | |
80 | if (!compr_ret) { | |
81 | ret = this->compr; | |
82 | this->stat_compr_blocks++; | |
83 | this->stat_compr_orig_size += *datalen; | |
84 | this->stat_compr_new_size += *cdatalen; | |
85 | break; | |
86 | } | |
87 | } | |
88 | spin_unlock(&jffs2_compressor_list_lock); | |
89 | if (ret == JFFS2_COMPR_NONE) kfree(output_buf); | |
90 | break; | |
91 | case JFFS2_COMPR_MODE_SIZE: | |
92 | orig_slen = *datalen; | |
93 | orig_dlen = *cdatalen; | |
94 | spin_lock(&jffs2_compressor_list_lock); | |
95 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
96 | /* Skip decompress-only backwards-compatibility and disabled modules */ | |
97 | if ((!this->compress)||(this->disabled)) | |
98 | continue; | |
99 | /* Allocating memory for output buffer if necessary */ | |
100 | if ((this->compr_buf_size<orig_dlen)&&(this->compr_buf)) { | |
101 | spin_unlock(&jffs2_compressor_list_lock); | |
102 | kfree(this->compr_buf); | |
103 | spin_lock(&jffs2_compressor_list_lock); | |
104 | this->compr_buf_size=0; | |
105 | this->compr_buf=NULL; | |
106 | } | |
107 | if (!this->compr_buf) { | |
108 | spin_unlock(&jffs2_compressor_list_lock); | |
109 | tmp_buf = kmalloc(orig_dlen,GFP_KERNEL); | |
110 | spin_lock(&jffs2_compressor_list_lock); | |
111 | if (!tmp_buf) { | |
112 | printk(KERN_WARNING "JFFS2: No memory for compressor allocation. (%d bytes)\n",orig_dlen); | |
113 | continue; | |
114 | } | |
115 | else { | |
116 | this->compr_buf = tmp_buf; | |
117 | this->compr_buf_size = orig_dlen; | |
118 | } | |
119 | } | |
120 | this->usecount++; | |
121 | spin_unlock(&jffs2_compressor_list_lock); | |
122 | *datalen = orig_slen; | |
123 | *cdatalen = orig_dlen; | |
124 | compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen, NULL); | |
125 | spin_lock(&jffs2_compressor_list_lock); | |
126 | this->usecount--; | |
127 | if (!compr_ret) { | |
128 | if ((!best_dlen)||(best_dlen>*cdatalen)) { | |
129 | best_dlen = *cdatalen; | |
130 | best_slen = *datalen; | |
131 | best = this; | |
132 | } | |
133 | } | |
134 | } | |
135 | if (best_dlen) { | |
136 | *cdatalen = best_dlen; | |
137 | *datalen = best_slen; | |
138 | output_buf = best->compr_buf; | |
139 | best->compr_buf = NULL; | |
140 | best->compr_buf_size = 0; | |
141 | best->stat_compr_blocks++; | |
142 | best->stat_compr_orig_size += best_slen; | |
143 | best->stat_compr_new_size += best_dlen; | |
144 | ret = best->compr; | |
145 | } | |
146 | spin_unlock(&jffs2_compressor_list_lock); | |
147 | break; | |
148 | default: | |
149 | printk(KERN_ERR "JFFS2: unknow compression mode.\n"); | |
150 | } | |
151 | out: | |
152 | if (ret == JFFS2_COMPR_NONE) { | |
153 | *cpage_out = data_in; | |
154 | *datalen = *cdatalen; | |
155 | none_stat_compr_blocks++; | |
156 | none_stat_compr_size += *datalen; | |
157 | } | |
158 | else { | |
159 | *cpage_out = output_buf; | |
160 | } | |
161 | return ret; | |
162 | } | |
163 | ||
164 | int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f, | |
182ec4ee | 165 | uint16_t comprtype, unsigned char *cdata_in, |
1da177e4 LT |
166 | unsigned char *data_out, uint32_t cdatalen, uint32_t datalen) |
167 | { | |
168 | struct jffs2_compressor *this; | |
169 | int ret; | |
170 | ||
171 | /* Older code had a bug where it would write non-zero 'usercompr' | |
172 | fields. Deal with it. */ | |
173 | if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB) | |
174 | comprtype &= 0xff; | |
175 | ||
176 | switch (comprtype & 0xff) { | |
177 | case JFFS2_COMPR_NONE: | |
178 | /* This should be special-cased elsewhere, but we might as well deal with it */ | |
179 | memcpy(data_out, cdata_in, datalen); | |
180 | none_stat_decompr_blocks++; | |
181 | break; | |
182 | case JFFS2_COMPR_ZERO: | |
183 | memset(data_out, 0, datalen); | |
184 | break; | |
185 | default: | |
186 | spin_lock(&jffs2_compressor_list_lock); | |
187 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
188 | if (comprtype == this->compr) { | |
189 | this->usecount++; | |
190 | spin_unlock(&jffs2_compressor_list_lock); | |
191 | ret = this->decompress(cdata_in, data_out, cdatalen, datalen, NULL); | |
192 | spin_lock(&jffs2_compressor_list_lock); | |
193 | if (ret) { | |
194 | printk(KERN_WARNING "Decompressor \"%s\" returned %d\n", this->name, ret); | |
195 | } | |
196 | else { | |
197 | this->stat_decompr_blocks++; | |
198 | } | |
199 | this->usecount--; | |
200 | spin_unlock(&jffs2_compressor_list_lock); | |
201 | return ret; | |
202 | } | |
203 | } | |
204 | printk(KERN_WARNING "JFFS2 compression type 0x%02x not available.\n", comprtype); | |
205 | spin_unlock(&jffs2_compressor_list_lock); | |
206 | return -EIO; | |
207 | } | |
208 | return 0; | |
209 | } | |
210 | ||
211 | int jffs2_register_compressor(struct jffs2_compressor *comp) | |
212 | { | |
213 | struct jffs2_compressor *this; | |
214 | ||
215 | if (!comp->name) { | |
216 | printk(KERN_WARNING "NULL compressor name at registering JFFS2 compressor. Failed.\n"); | |
217 | return -1; | |
218 | } | |
219 | comp->compr_buf_size=0; | |
220 | comp->compr_buf=NULL; | |
221 | comp->usecount=0; | |
222 | comp->stat_compr_orig_size=0; | |
223 | comp->stat_compr_new_size=0; | |
224 | comp->stat_compr_blocks=0; | |
225 | comp->stat_decompr_blocks=0; | |
226 | D1(printk(KERN_DEBUG "Registering JFFS2 compressor \"%s\"\n", comp->name)); | |
227 | ||
228 | spin_lock(&jffs2_compressor_list_lock); | |
229 | ||
230 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
231 | if (this->priority < comp->priority) { | |
232 | list_add(&comp->list, this->list.prev); | |
233 | goto out; | |
234 | } | |
235 | } | |
236 | list_add_tail(&comp->list, &jffs2_compressor_list); | |
237 | out: | |
238 | D2(list_for_each_entry(this, &jffs2_compressor_list, list) { | |
239 | printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority); | |
240 | }) | |
241 | ||
242 | spin_unlock(&jffs2_compressor_list_lock); | |
243 | ||
244 | return 0; | |
245 | } | |
246 | ||
247 | int jffs2_unregister_compressor(struct jffs2_compressor *comp) | |
248 | { | |
249 | D2(struct jffs2_compressor *this;) | |
250 | ||
251 | D1(printk(KERN_DEBUG "Unregistering JFFS2 compressor \"%s\"\n", comp->name)); | |
252 | ||
253 | spin_lock(&jffs2_compressor_list_lock); | |
254 | ||
255 | if (comp->usecount) { | |
256 | spin_unlock(&jffs2_compressor_list_lock); | |
257 | printk(KERN_WARNING "JFFS2: Compressor modul is in use. Unregister failed.\n"); | |
258 | return -1; | |
259 | } | |
260 | list_del(&comp->list); | |
261 | ||
262 | D2(list_for_each_entry(this, &jffs2_compressor_list, list) { | |
263 | printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority); | |
264 | }) | |
265 | spin_unlock(&jffs2_compressor_list_lock); | |
266 | return 0; | |
267 | } | |
268 | ||
1da177e4 LT |
269 | void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig) |
270 | { | |
271 | if (orig != comprbuf) | |
272 | kfree(comprbuf); | |
273 | } | |
274 | ||
7d2beb13 | 275 | int __init jffs2_compressors_init(void) |
1da177e4 LT |
276 | { |
277 | /* Registering compressors */ | |
278 | #ifdef CONFIG_JFFS2_ZLIB | |
279 | jffs2_zlib_init(); | |
280 | #endif | |
281 | #ifdef CONFIG_JFFS2_RTIME | |
282 | jffs2_rtime_init(); | |
283 | #endif | |
284 | #ifdef CONFIG_JFFS2_RUBIN | |
285 | jffs2_rubinmips_init(); | |
286 | jffs2_dynrubin_init(); | |
287 | #endif | |
1da177e4 LT |
288 | /* Setting default compression mode */ |
289 | #ifdef CONFIG_JFFS2_CMODE_NONE | |
290 | jffs2_compression_mode = JFFS2_COMPR_MODE_NONE; | |
291 | D1(printk(KERN_INFO "JFFS2: default compression mode: none\n");) | |
292 | #else | |
293 | #ifdef CONFIG_JFFS2_CMODE_SIZE | |
294 | jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE; | |
295 | D1(printk(KERN_INFO "JFFS2: default compression mode: size\n");) | |
296 | #else | |
297 | D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");) | |
298 | #endif | |
299 | #endif | |
300 | return 0; | |
301 | } | |
302 | ||
3bcc86f5 | 303 | int jffs2_compressors_exit(void) |
1da177e4 LT |
304 | { |
305 | /* Unregistering compressors */ | |
1da177e4 LT |
306 | #ifdef CONFIG_JFFS2_RUBIN |
307 | jffs2_dynrubin_exit(); | |
308 | jffs2_rubinmips_exit(); | |
309 | #endif | |
310 | #ifdef CONFIG_JFFS2_RTIME | |
311 | jffs2_rtime_exit(); | |
312 | #endif | |
313 | #ifdef CONFIG_JFFS2_ZLIB | |
314 | jffs2_zlib_exit(); | |
315 | #endif | |
316 | return 0; | |
317 | } |