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1da177e4 LT |
1 | /* |
2 | * JFFS2 -- Journalling Flash File System, Version 2. | |
3 | * | |
4 | * Copyright (C) 2001-2003 Red Hat, Inc. | |
5 | * Created by Arjan van de Ven <arjanv@redhat.com> | |
6 | * | |
7 | * Copyright (C) 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>, | |
8 | * University of Szeged, Hungary | |
9 | * | |
10 | * For licensing information, see the file 'LICENCE' in this directory. | |
11 | * | |
12 | * $Id: compr.c,v 1.42 2004/08/07 21:56:08 dwmw2 Exp $ | |
13 | * | |
14 | */ | |
15 | ||
16 | #include "compr.h" | |
17 | ||
18 | static DEFINE_SPINLOCK(jffs2_compressor_list_lock); | |
19 | ||
20 | /* Available compressors are on this list */ | |
21 | static LIST_HEAD(jffs2_compressor_list); | |
22 | ||
23 | /* Actual compression mode */ | |
24 | static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY; | |
25 | ||
26 | /* Statistics for blocks stored without compression */ | |
27 | static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0; | |
28 | ||
29 | /* jffs2_compress: | |
30 | * @data: Pointer to uncompressed data | |
31 | * @cdata: Pointer to returned pointer to buffer for compressed data | |
32 | * @datalen: On entry, holds the amount of data available for compression. | |
33 | * On exit, expected to hold the amount of data actually compressed. | |
34 | * @cdatalen: On entry, holds the amount of space available for compressed | |
35 | * data. On exit, expected to hold the actual size of the compressed | |
36 | * data. | |
37 | * | |
38 | * Returns: Lower byte to be stored with data indicating compression type used. | |
39 | * Zero is used to show that the data could not be compressed - the | |
40 | * compressed version was actually larger than the original. | |
41 | * Upper byte will be used later. (soon) | |
42 | * | |
43 | * If the cdata buffer isn't large enough to hold all the uncompressed data, | |
44 | * jffs2_compress should compress as much as will fit, and should set | |
45 | * *datalen accordingly to show the amount of data which were compressed. | |
46 | */ | |
47 | uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f, | |
48 | unsigned char *data_in, unsigned char **cpage_out, | |
49 | uint32_t *datalen, uint32_t *cdatalen) | |
50 | { | |
51 | int ret = JFFS2_COMPR_NONE; | |
52 | int compr_ret; | |
53 | struct jffs2_compressor *this, *best=NULL; | |
54 | unsigned char *output_buf = NULL, *tmp_buf; | |
55 | uint32_t orig_slen, orig_dlen; | |
56 | uint32_t best_slen=0, best_dlen=0; | |
57 | ||
58 | switch (jffs2_compression_mode) { | |
59 | case JFFS2_COMPR_MODE_NONE: | |
60 | break; | |
61 | case JFFS2_COMPR_MODE_PRIORITY: | |
62 | output_buf = kmalloc(*cdatalen,GFP_KERNEL); | |
63 | if (!output_buf) { | |
64 | printk(KERN_WARNING "JFFS2: No memory for compressor allocation. Compression failed.\n"); | |
65 | goto out; | |
66 | } | |
67 | orig_slen = *datalen; | |
68 | orig_dlen = *cdatalen; | |
69 | spin_lock(&jffs2_compressor_list_lock); | |
70 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
71 | /* Skip decompress-only backwards-compatibility and disabled modules */ | |
72 | if ((!this->compress)||(this->disabled)) | |
73 | continue; | |
74 | ||
75 | this->usecount++; | |
76 | spin_unlock(&jffs2_compressor_list_lock); | |
77 | *datalen = orig_slen; | |
78 | *cdatalen = orig_dlen; | |
79 | compr_ret = this->compress(data_in, output_buf, datalen, cdatalen, NULL); | |
80 | spin_lock(&jffs2_compressor_list_lock); | |
81 | this->usecount--; | |
82 | if (!compr_ret) { | |
83 | ret = this->compr; | |
84 | this->stat_compr_blocks++; | |
85 | this->stat_compr_orig_size += *datalen; | |
86 | this->stat_compr_new_size += *cdatalen; | |
87 | break; | |
88 | } | |
89 | } | |
90 | spin_unlock(&jffs2_compressor_list_lock); | |
91 | if (ret == JFFS2_COMPR_NONE) kfree(output_buf); | |
92 | break; | |
93 | case JFFS2_COMPR_MODE_SIZE: | |
94 | orig_slen = *datalen; | |
95 | orig_dlen = *cdatalen; | |
96 | spin_lock(&jffs2_compressor_list_lock); | |
97 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
98 | /* Skip decompress-only backwards-compatibility and disabled modules */ | |
99 | if ((!this->compress)||(this->disabled)) | |
100 | continue; | |
101 | /* Allocating memory for output buffer if necessary */ | |
102 | if ((this->compr_buf_size<orig_dlen)&&(this->compr_buf)) { | |
103 | spin_unlock(&jffs2_compressor_list_lock); | |
104 | kfree(this->compr_buf); | |
105 | spin_lock(&jffs2_compressor_list_lock); | |
106 | this->compr_buf_size=0; | |
107 | this->compr_buf=NULL; | |
108 | } | |
109 | if (!this->compr_buf) { | |
110 | spin_unlock(&jffs2_compressor_list_lock); | |
111 | tmp_buf = kmalloc(orig_dlen,GFP_KERNEL); | |
112 | spin_lock(&jffs2_compressor_list_lock); | |
113 | if (!tmp_buf) { | |
114 | printk(KERN_WARNING "JFFS2: No memory for compressor allocation. (%d bytes)\n",orig_dlen); | |
115 | continue; | |
116 | } | |
117 | else { | |
118 | this->compr_buf = tmp_buf; | |
119 | this->compr_buf_size = orig_dlen; | |
120 | } | |
121 | } | |
122 | this->usecount++; | |
123 | spin_unlock(&jffs2_compressor_list_lock); | |
124 | *datalen = orig_slen; | |
125 | *cdatalen = orig_dlen; | |
126 | compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen, NULL); | |
127 | spin_lock(&jffs2_compressor_list_lock); | |
128 | this->usecount--; | |
129 | if (!compr_ret) { | |
130 | if ((!best_dlen)||(best_dlen>*cdatalen)) { | |
131 | best_dlen = *cdatalen; | |
132 | best_slen = *datalen; | |
133 | best = this; | |
134 | } | |
135 | } | |
136 | } | |
137 | if (best_dlen) { | |
138 | *cdatalen = best_dlen; | |
139 | *datalen = best_slen; | |
140 | output_buf = best->compr_buf; | |
141 | best->compr_buf = NULL; | |
142 | best->compr_buf_size = 0; | |
143 | best->stat_compr_blocks++; | |
144 | best->stat_compr_orig_size += best_slen; | |
145 | best->stat_compr_new_size += best_dlen; | |
146 | ret = best->compr; | |
147 | } | |
148 | spin_unlock(&jffs2_compressor_list_lock); | |
149 | break; | |
150 | default: | |
151 | printk(KERN_ERR "JFFS2: unknow compression mode.\n"); | |
152 | } | |
153 | out: | |
154 | if (ret == JFFS2_COMPR_NONE) { | |
155 | *cpage_out = data_in; | |
156 | *datalen = *cdatalen; | |
157 | none_stat_compr_blocks++; | |
158 | none_stat_compr_size += *datalen; | |
159 | } | |
160 | else { | |
161 | *cpage_out = output_buf; | |
162 | } | |
163 | return ret; | |
164 | } | |
165 | ||
166 | int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f, | |
167 | uint16_t comprtype, unsigned char *cdata_in, | |
168 | unsigned char *data_out, uint32_t cdatalen, uint32_t datalen) | |
169 | { | |
170 | struct jffs2_compressor *this; | |
171 | int ret; | |
172 | ||
173 | /* Older code had a bug where it would write non-zero 'usercompr' | |
174 | fields. Deal with it. */ | |
175 | if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB) | |
176 | comprtype &= 0xff; | |
177 | ||
178 | switch (comprtype & 0xff) { | |
179 | case JFFS2_COMPR_NONE: | |
180 | /* This should be special-cased elsewhere, but we might as well deal with it */ | |
181 | memcpy(data_out, cdata_in, datalen); | |
182 | none_stat_decompr_blocks++; | |
183 | break; | |
184 | case JFFS2_COMPR_ZERO: | |
185 | memset(data_out, 0, datalen); | |
186 | break; | |
187 | default: | |
188 | spin_lock(&jffs2_compressor_list_lock); | |
189 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
190 | if (comprtype == this->compr) { | |
191 | this->usecount++; | |
192 | spin_unlock(&jffs2_compressor_list_lock); | |
193 | ret = this->decompress(cdata_in, data_out, cdatalen, datalen, NULL); | |
194 | spin_lock(&jffs2_compressor_list_lock); | |
195 | if (ret) { | |
196 | printk(KERN_WARNING "Decompressor \"%s\" returned %d\n", this->name, ret); | |
197 | } | |
198 | else { | |
199 | this->stat_decompr_blocks++; | |
200 | } | |
201 | this->usecount--; | |
202 | spin_unlock(&jffs2_compressor_list_lock); | |
203 | return ret; | |
204 | } | |
205 | } | |
206 | printk(KERN_WARNING "JFFS2 compression type 0x%02x not available.\n", comprtype); | |
207 | spin_unlock(&jffs2_compressor_list_lock); | |
208 | return -EIO; | |
209 | } | |
210 | return 0; | |
211 | } | |
212 | ||
213 | int jffs2_register_compressor(struct jffs2_compressor *comp) | |
214 | { | |
215 | struct jffs2_compressor *this; | |
216 | ||
217 | if (!comp->name) { | |
218 | printk(KERN_WARNING "NULL compressor name at registering JFFS2 compressor. Failed.\n"); | |
219 | return -1; | |
220 | } | |
221 | comp->compr_buf_size=0; | |
222 | comp->compr_buf=NULL; | |
223 | comp->usecount=0; | |
224 | comp->stat_compr_orig_size=0; | |
225 | comp->stat_compr_new_size=0; | |
226 | comp->stat_compr_blocks=0; | |
227 | comp->stat_decompr_blocks=0; | |
228 | D1(printk(KERN_DEBUG "Registering JFFS2 compressor \"%s\"\n", comp->name)); | |
229 | ||
230 | spin_lock(&jffs2_compressor_list_lock); | |
231 | ||
232 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
233 | if (this->priority < comp->priority) { | |
234 | list_add(&comp->list, this->list.prev); | |
235 | goto out; | |
236 | } | |
237 | } | |
238 | list_add_tail(&comp->list, &jffs2_compressor_list); | |
239 | out: | |
240 | D2(list_for_each_entry(this, &jffs2_compressor_list, list) { | |
241 | printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority); | |
242 | }) | |
243 | ||
244 | spin_unlock(&jffs2_compressor_list_lock); | |
245 | ||
246 | return 0; | |
247 | } | |
248 | ||
249 | int jffs2_unregister_compressor(struct jffs2_compressor *comp) | |
250 | { | |
251 | D2(struct jffs2_compressor *this;) | |
252 | ||
253 | D1(printk(KERN_DEBUG "Unregistering JFFS2 compressor \"%s\"\n", comp->name)); | |
254 | ||
255 | spin_lock(&jffs2_compressor_list_lock); | |
256 | ||
257 | if (comp->usecount) { | |
258 | spin_unlock(&jffs2_compressor_list_lock); | |
259 | printk(KERN_WARNING "JFFS2: Compressor modul is in use. Unregister failed.\n"); | |
260 | return -1; | |
261 | } | |
262 | list_del(&comp->list); | |
263 | ||
264 | D2(list_for_each_entry(this, &jffs2_compressor_list, list) { | |
265 | printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority); | |
266 | }) | |
267 | spin_unlock(&jffs2_compressor_list_lock); | |
268 | return 0; | |
269 | } | |
270 | ||
271 | #ifdef CONFIG_JFFS2_PROC | |
272 | ||
273 | #define JFFS2_STAT_BUF_SIZE 16000 | |
274 | ||
275 | char *jffs2_list_compressors(void) | |
276 | { | |
277 | struct jffs2_compressor *this; | |
278 | char *buf, *act_buf; | |
279 | ||
280 | act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL); | |
281 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
282 | act_buf += sprintf(act_buf, "%10s priority:%d ", this->name, this->priority); | |
283 | if ((this->disabled)||(!this->compress)) | |
284 | act_buf += sprintf(act_buf,"disabled"); | |
285 | else | |
286 | act_buf += sprintf(act_buf,"enabled"); | |
287 | act_buf += sprintf(act_buf,"\n"); | |
288 | } | |
289 | return buf; | |
290 | } | |
291 | ||
292 | char *jffs2_stats(void) | |
293 | { | |
294 | struct jffs2_compressor *this; | |
295 | char *buf, *act_buf; | |
296 | ||
297 | act_buf = buf = kmalloc(JFFS2_STAT_BUF_SIZE,GFP_KERNEL); | |
298 | ||
299 | act_buf += sprintf(act_buf,"JFFS2 compressor statistics:\n"); | |
300 | act_buf += sprintf(act_buf,"%10s ","none"); | |
301 | act_buf += sprintf(act_buf,"compr: %d blocks (%d) decompr: %d blocks\n", none_stat_compr_blocks, | |
302 | none_stat_compr_size, none_stat_decompr_blocks); | |
303 | spin_lock(&jffs2_compressor_list_lock); | |
304 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
305 | act_buf += sprintf(act_buf,"%10s ",this->name); | |
306 | if ((this->disabled)||(!this->compress)) | |
307 | act_buf += sprintf(act_buf,"- "); | |
308 | else | |
309 | act_buf += sprintf(act_buf,"+ "); | |
310 | act_buf += sprintf(act_buf,"compr: %d blocks (%d/%d) decompr: %d blocks ", this->stat_compr_blocks, | |
311 | this->stat_compr_new_size, this->stat_compr_orig_size, | |
312 | this->stat_decompr_blocks); | |
313 | act_buf += sprintf(act_buf,"\n"); | |
314 | } | |
315 | spin_unlock(&jffs2_compressor_list_lock); | |
316 | ||
317 | return buf; | |
318 | } | |
319 | ||
320 | char *jffs2_get_compression_mode_name(void) | |
321 | { | |
322 | switch (jffs2_compression_mode) { | |
323 | case JFFS2_COMPR_MODE_NONE: | |
324 | return "none"; | |
325 | case JFFS2_COMPR_MODE_PRIORITY: | |
326 | return "priority"; | |
327 | case JFFS2_COMPR_MODE_SIZE: | |
328 | return "size"; | |
329 | } | |
330 | return "unkown"; | |
331 | } | |
332 | ||
333 | int jffs2_set_compression_mode_name(const char *name) | |
334 | { | |
335 | if (!strcmp("none",name)) { | |
336 | jffs2_compression_mode = JFFS2_COMPR_MODE_NONE; | |
337 | return 0; | |
338 | } | |
339 | if (!strcmp("priority",name)) { | |
340 | jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY; | |
341 | return 0; | |
342 | } | |
343 | if (!strcmp("size",name)) { | |
344 | jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE; | |
345 | return 0; | |
346 | } | |
347 | return 1; | |
348 | } | |
349 | ||
350 | static int jffs2_compressor_Xable(const char *name, int disabled) | |
351 | { | |
352 | struct jffs2_compressor *this; | |
353 | spin_lock(&jffs2_compressor_list_lock); | |
354 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
355 | if (!strcmp(this->name, name)) { | |
356 | this->disabled = disabled; | |
357 | spin_unlock(&jffs2_compressor_list_lock); | |
358 | return 0; | |
359 | } | |
360 | } | |
361 | spin_unlock(&jffs2_compressor_list_lock); | |
362 | printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name); | |
363 | return 1; | |
364 | } | |
365 | ||
366 | int jffs2_enable_compressor_name(const char *name) | |
367 | { | |
368 | return jffs2_compressor_Xable(name, 0); | |
369 | } | |
370 | ||
371 | int jffs2_disable_compressor_name(const char *name) | |
372 | { | |
373 | return jffs2_compressor_Xable(name, 1); | |
374 | } | |
375 | ||
376 | int jffs2_set_compressor_priority(const char *name, int priority) | |
377 | { | |
378 | struct jffs2_compressor *this,*comp; | |
379 | spin_lock(&jffs2_compressor_list_lock); | |
380 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
381 | if (!strcmp(this->name, name)) { | |
382 | this->priority = priority; | |
383 | comp = this; | |
384 | goto reinsert; | |
385 | } | |
386 | } | |
387 | spin_unlock(&jffs2_compressor_list_lock); | |
388 | printk(KERN_WARNING "JFFS2: compressor %s not found.\n",name); | |
389 | return 1; | |
390 | reinsert: | |
391 | /* list is sorted in the order of priority, so if | |
392 | we change it we have to reinsert it into the | |
393 | good place */ | |
394 | list_del(&comp->list); | |
395 | list_for_each_entry(this, &jffs2_compressor_list, list) { | |
396 | if (this->priority < comp->priority) { | |
397 | list_add(&comp->list, this->list.prev); | |
398 | spin_unlock(&jffs2_compressor_list_lock); | |
399 | return 0; | |
400 | } | |
401 | } | |
402 | list_add_tail(&comp->list, &jffs2_compressor_list); | |
403 | spin_unlock(&jffs2_compressor_list_lock); | |
404 | return 0; | |
405 | } | |
406 | ||
407 | #endif | |
408 | ||
409 | void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig) | |
410 | { | |
411 | if (orig != comprbuf) | |
412 | kfree(comprbuf); | |
413 | } | |
414 | ||
415 | int jffs2_compressors_init(void) | |
416 | { | |
417 | /* Registering compressors */ | |
418 | #ifdef CONFIG_JFFS2_ZLIB | |
419 | jffs2_zlib_init(); | |
420 | #endif | |
421 | #ifdef CONFIG_JFFS2_RTIME | |
422 | jffs2_rtime_init(); | |
423 | #endif | |
424 | #ifdef CONFIG_JFFS2_RUBIN | |
425 | jffs2_rubinmips_init(); | |
426 | jffs2_dynrubin_init(); | |
427 | #endif | |
428 | #ifdef CONFIG_JFFS2_LZARI | |
429 | jffs2_lzari_init(); | |
430 | #endif | |
431 | #ifdef CONFIG_JFFS2_LZO | |
432 | jffs2_lzo_init(); | |
433 | #endif | |
434 | /* Setting default compression mode */ | |
435 | #ifdef CONFIG_JFFS2_CMODE_NONE | |
436 | jffs2_compression_mode = JFFS2_COMPR_MODE_NONE; | |
437 | D1(printk(KERN_INFO "JFFS2: default compression mode: none\n");) | |
438 | #else | |
439 | #ifdef CONFIG_JFFS2_CMODE_SIZE | |
440 | jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE; | |
441 | D1(printk(KERN_INFO "JFFS2: default compression mode: size\n");) | |
442 | #else | |
443 | D1(printk(KERN_INFO "JFFS2: default compression mode: priority\n");) | |
444 | #endif | |
445 | #endif | |
446 | return 0; | |
447 | } | |
448 | ||
449 | int jffs2_compressors_exit(void) | |
450 | { | |
451 | /* Unregistering compressors */ | |
452 | #ifdef CONFIG_JFFS2_LZO | |
453 | jffs2_lzo_exit(); | |
454 | #endif | |
455 | #ifdef CONFIG_JFFS2_LZARI | |
456 | jffs2_lzari_exit(); | |
457 | #endif | |
458 | #ifdef CONFIG_JFFS2_RUBIN | |
459 | jffs2_dynrubin_exit(); | |
460 | jffs2_rubinmips_exit(); | |
461 | #endif | |
462 | #ifdef CONFIG_JFFS2_RTIME | |
463 | jffs2_rtime_exit(); | |
464 | #endif | |
465 | #ifdef CONFIG_JFFS2_ZLIB | |
466 | jffs2_zlib_exit(); | |
467 | #endif | |
468 | return 0; | |
469 | } |