1 | /* |
---|
2 | * JFFS2 -- Journalling Flash File System, Version 2. |
---|
3 | * |
---|
4 | * Copyright © 2001-2007 Red Hat, Inc. |
---|
5 | * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org> |
---|
6 | * Copyright © 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>, |
---|
7 | * University of Szeged, Hungary |
---|
8 | * |
---|
9 | * Created by Arjan van de Ven <arjan@infradead.org> |
---|
10 | * |
---|
11 | * For licensing information, see the file 'LICENCE' in this directory. |
---|
12 | * |
---|
13 | */ |
---|
14 | |
---|
15 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
---|
16 | |
---|
17 | #include "compr.h" |
---|
18 | |
---|
19 | static DEFINE_SPINLOCK(jffs2_compressor_list_lock); |
---|
20 | |
---|
21 | /* Available compressors are on this list */ |
---|
22 | static LIST_HEAD(jffs2_compressor_list); |
---|
23 | |
---|
24 | /* Actual compression mode */ |
---|
25 | static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY; |
---|
26 | |
---|
27 | /* Statistics for blocks stored without compression */ |
---|
28 | static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0; |
---|
29 | |
---|
30 | |
---|
31 | /* |
---|
32 | * Return 1 to use this compression |
---|
33 | */ |
---|
34 | static int jffs2_is_best_compression(struct jffs2_compressor *this, |
---|
35 | struct jffs2_compressor *best, uint32_t size, uint32_t bestsize) |
---|
36 | { |
---|
37 | switch (jffs2_compression_mode) { |
---|
38 | case JFFS2_COMPR_MODE_SIZE: |
---|
39 | if (bestsize > size) |
---|
40 | return 1; |
---|
41 | return 0; |
---|
42 | case JFFS2_COMPR_MODE_FAVOURLZO: |
---|
43 | if ((this->compr == JFFS2_COMPR_LZO) && (bestsize > size)) |
---|
44 | return 1; |
---|
45 | if ((best->compr != JFFS2_COMPR_LZO) && (bestsize > size)) |
---|
46 | return 1; |
---|
47 | if ((this->compr == JFFS2_COMPR_LZO) && (bestsize > (size * FAVOUR_LZO_PERCENT / 100))) |
---|
48 | return 1; |
---|
49 | if ((bestsize * FAVOUR_LZO_PERCENT / 100) > size) |
---|
50 | return 1; |
---|
51 | |
---|
52 | return 0; |
---|
53 | } |
---|
54 | /* Shouldn't happen */ |
---|
55 | return 0; |
---|
56 | } |
---|
57 | |
---|
58 | /* |
---|
59 | * jffs2_selected_compress: |
---|
60 | * @compr: Explicit compression type to use (ie, JFFS2_COMPR_ZLIB). |
---|
61 | * If 0, just take the first available compression mode. |
---|
62 | * @data_in: Pointer to uncompressed data |
---|
63 | * @cpage_out: Pointer to returned pointer to buffer for compressed data |
---|
64 | * @datalen: On entry, holds the amount of data available for compression. |
---|
65 | * On exit, expected to hold the amount of data actually compressed. |
---|
66 | * @cdatalen: On entry, holds the amount of space available for compressed |
---|
67 | * data. On exit, expected to hold the actual size of the compressed |
---|
68 | * data. |
---|
69 | * |
---|
70 | * Returns: the compression type used. Zero is used to show that the data |
---|
71 | * could not be compressed; probably because we couldn't find the requested |
---|
72 | * compression mode. |
---|
73 | */ |
---|
74 | static int jffs2_selected_compress(u8 compr, unsigned char *data_in, |
---|
75 | unsigned char **cpage_out, u32 *datalen, u32 *cdatalen) |
---|
76 | { |
---|
77 | struct jffs2_compressor *this; |
---|
78 | int err, ret = JFFS2_COMPR_NONE; |
---|
79 | uint32_t orig_slen, orig_dlen; |
---|
80 | char *output_buf; |
---|
81 | |
---|
82 | output_buf = kmalloc(*cdatalen, GFP_KERNEL); |
---|
83 | if (!output_buf) { |
---|
84 | pr_warn("No memory for compressor allocation. Compression failed.\n"); |
---|
85 | return ret; |
---|
86 | } |
---|
87 | orig_slen = *datalen; |
---|
88 | orig_dlen = *cdatalen; |
---|
89 | spin_lock(&jffs2_compressor_list_lock); |
---|
90 | list_for_each_entry(this, &jffs2_compressor_list, list) { |
---|
91 | /* Skip decompress-only and disabled modules */ |
---|
92 | if (!this->compress || this->disabled) |
---|
93 | continue; |
---|
94 | |
---|
95 | /* Skip if not the desired compression type */ |
---|
96 | if (compr && (compr != this->compr)) |
---|
97 | continue; |
---|
98 | |
---|
99 | /* |
---|
100 | * Either compression type was unspecified, or we found our |
---|
101 | * compressor; either way, we're good to go. |
---|
102 | */ |
---|
103 | this->usecount++; |
---|
104 | spin_unlock(&jffs2_compressor_list_lock); |
---|
105 | |
---|
106 | *datalen = orig_slen; |
---|
107 | *cdatalen = orig_dlen; |
---|
108 | err = this->compress(data_in, output_buf, datalen, cdatalen); |
---|
109 | |
---|
110 | spin_lock(&jffs2_compressor_list_lock); |
---|
111 | this->usecount--; |
---|
112 | if (!err) { |
---|
113 | /* Success */ |
---|
114 | ret = this->compr; |
---|
115 | this->stat_compr_blocks++; |
---|
116 | this->stat_compr_orig_size += *datalen; |
---|
117 | this->stat_compr_new_size += *cdatalen; |
---|
118 | break; |
---|
119 | } |
---|
120 | } |
---|
121 | spin_unlock(&jffs2_compressor_list_lock); |
---|
122 | if (ret == JFFS2_COMPR_NONE) |
---|
123 | kfree(output_buf); |
---|
124 | else |
---|
125 | *cpage_out = output_buf; |
---|
126 | |
---|
127 | return ret; |
---|
128 | } |
---|
129 | |
---|
130 | /* jffs2_compress: |
---|
131 | * @data_in: Pointer to uncompressed data |
---|
132 | * @cpage_out: Pointer to returned pointer to buffer for compressed data |
---|
133 | * @datalen: On entry, holds the amount of data available for compression. |
---|
134 | * On exit, expected to hold the amount of data actually compressed. |
---|
135 | * @cdatalen: On entry, holds the amount of space available for compressed |
---|
136 | * data. On exit, expected to hold the actual size of the compressed |
---|
137 | * data. |
---|
138 | * |
---|
139 | * Returns: Lower byte to be stored with data indicating compression type used. |
---|
140 | * Zero is used to show that the data could not be compressed - the |
---|
141 | * compressed version was actually larger than the original. |
---|
142 | * Upper byte will be used later. (soon) |
---|
143 | * |
---|
144 | * If the cdata buffer isn't large enough to hold all the uncompressed data, |
---|
145 | * jffs2_compress should compress as much as will fit, and should set |
---|
146 | * *datalen accordingly to show the amount of data which were compressed. |
---|
147 | */ |
---|
148 | uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f, |
---|
149 | unsigned char *data_in, unsigned char **cpage_out, |
---|
150 | uint32_t *datalen, uint32_t *cdatalen) |
---|
151 | { |
---|
152 | int ret = JFFS2_COMPR_NONE; |
---|
153 | int mode, compr_ret; |
---|
154 | struct jffs2_compressor *this, *best=NULL; |
---|
155 | unsigned char *output_buf = NULL, *tmp_buf; |
---|
156 | uint32_t orig_slen, orig_dlen; |
---|
157 | uint32_t best_slen=0, best_dlen=0; |
---|
158 | |
---|
159 | if (c->mount_opts.override_compr) |
---|
160 | mode = c->mount_opts.compr; |
---|
161 | else |
---|
162 | mode = jffs2_compression_mode; |
---|
163 | |
---|
164 | switch (mode) { |
---|
165 | case JFFS2_COMPR_MODE_NONE: |
---|
166 | break; |
---|
167 | case JFFS2_COMPR_MODE_PRIORITY: |
---|
168 | ret = jffs2_selected_compress(0, data_in, cpage_out, datalen, |
---|
169 | cdatalen); |
---|
170 | break; |
---|
171 | case JFFS2_COMPR_MODE_SIZE: |
---|
172 | case JFFS2_COMPR_MODE_FAVOURLZO: |
---|
173 | orig_slen = *datalen; |
---|
174 | orig_dlen = *cdatalen; |
---|
175 | spin_lock(&jffs2_compressor_list_lock); |
---|
176 | list_for_each_entry(this, &jffs2_compressor_list, list) { |
---|
177 | /* Skip decompress-only backwards-compatibility and disabled modules */ |
---|
178 | if ((!this->compress)||(this->disabled)) |
---|
179 | continue; |
---|
180 | /* Allocating memory for output buffer if necessary */ |
---|
181 | if ((this->compr_buf_size < orig_slen) && (this->compr_buf)) { |
---|
182 | spin_unlock(&jffs2_compressor_list_lock); |
---|
183 | kfree(this->compr_buf); |
---|
184 | spin_lock(&jffs2_compressor_list_lock); |
---|
185 | this->compr_buf_size=0; |
---|
186 | this->compr_buf=NULL; |
---|
187 | } |
---|
188 | if (!this->compr_buf) { |
---|
189 | spin_unlock(&jffs2_compressor_list_lock); |
---|
190 | tmp_buf = kmalloc(orig_slen, GFP_KERNEL); |
---|
191 | spin_lock(&jffs2_compressor_list_lock); |
---|
192 | if (!tmp_buf) { |
---|
193 | pr_warn("No memory for compressor allocation. (%d bytes)\n", |
---|
194 | orig_slen); |
---|
195 | continue; |
---|
196 | } |
---|
197 | else { |
---|
198 | this->compr_buf = tmp_buf; |
---|
199 | this->compr_buf_size = orig_slen; |
---|
200 | } |
---|
201 | } |
---|
202 | this->usecount++; |
---|
203 | spin_unlock(&jffs2_compressor_list_lock); |
---|
204 | *datalen = orig_slen; |
---|
205 | *cdatalen = orig_dlen; |
---|
206 | compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen); |
---|
207 | spin_lock(&jffs2_compressor_list_lock); |
---|
208 | this->usecount--; |
---|
209 | if (!compr_ret) { |
---|
210 | if (((!best_dlen) || jffs2_is_best_compression(this, best, *cdatalen, best_dlen)) |
---|
211 | && (*cdatalen < *datalen)) { |
---|
212 | best_dlen = *cdatalen; |
---|
213 | best_slen = *datalen; |
---|
214 | best = this; |
---|
215 | } |
---|
216 | } |
---|
217 | } |
---|
218 | if (best_dlen) { |
---|
219 | *cdatalen = best_dlen; |
---|
220 | *datalen = best_slen; |
---|
221 | output_buf = best->compr_buf; |
---|
222 | best->compr_buf = NULL; |
---|
223 | best->compr_buf_size = 0; |
---|
224 | best->stat_compr_blocks++; |
---|
225 | best->stat_compr_orig_size += best_slen; |
---|
226 | best->stat_compr_new_size += best_dlen; |
---|
227 | ret = best->compr; |
---|
228 | *cpage_out = output_buf; |
---|
229 | } |
---|
230 | spin_unlock(&jffs2_compressor_list_lock); |
---|
231 | break; |
---|
232 | case JFFS2_COMPR_MODE_FORCELZO: |
---|
233 | ret = jffs2_selected_compress(JFFS2_COMPR_LZO, data_in, |
---|
234 | cpage_out, datalen, cdatalen); |
---|
235 | break; |
---|
236 | case JFFS2_COMPR_MODE_FORCEZLIB: |
---|
237 | ret = jffs2_selected_compress(JFFS2_COMPR_ZLIB, data_in, |
---|
238 | cpage_out, datalen, cdatalen); |
---|
239 | break; |
---|
240 | default: |
---|
241 | pr_err("unknown compression mode\n"); |
---|
242 | } |
---|
243 | |
---|
244 | if (ret == JFFS2_COMPR_NONE) { |
---|
245 | *cpage_out = data_in; |
---|
246 | *datalen = *cdatalen; |
---|
247 | none_stat_compr_blocks++; |
---|
248 | none_stat_compr_size += *datalen; |
---|
249 | } |
---|
250 | return ret; |
---|
251 | } |
---|
252 | |
---|
253 | int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f, |
---|
254 | uint16_t comprtype, unsigned char *cdata_in, |
---|
255 | unsigned char *data_out, uint32_t cdatalen, uint32_t datalen) |
---|
256 | { |
---|
257 | struct jffs2_compressor *this; |
---|
258 | int ret; |
---|
259 | |
---|
260 | /* Older code had a bug where it would write non-zero 'usercompr' |
---|
261 | fields. Deal with it. */ |
---|
262 | if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB) |
---|
263 | comprtype &= 0xff; |
---|
264 | |
---|
265 | switch (comprtype & 0xff) { |
---|
266 | case JFFS2_COMPR_NONE: |
---|
267 | /* This should be special-cased elsewhere, but we might as well deal with it */ |
---|
268 | memcpy(data_out, cdata_in, datalen); |
---|
269 | none_stat_decompr_blocks++; |
---|
270 | break; |
---|
271 | case JFFS2_COMPR_ZERO: |
---|
272 | memset(data_out, 0, datalen); |
---|
273 | break; |
---|
274 | default: |
---|
275 | spin_lock(&jffs2_compressor_list_lock); |
---|
276 | list_for_each_entry(this, &jffs2_compressor_list, list) { |
---|
277 | if (comprtype == this->compr) { |
---|
278 | this->usecount++; |
---|
279 | spin_unlock(&jffs2_compressor_list_lock); |
---|
280 | ret = this->decompress(cdata_in, data_out, cdatalen, datalen); |
---|
281 | spin_lock(&jffs2_compressor_list_lock); |
---|
282 | if (ret) { |
---|
283 | pr_warn("Decompressor \"%s\" returned %d\n", |
---|
284 | this->name, ret); |
---|
285 | } |
---|
286 | else { |
---|
287 | this->stat_decompr_blocks++; |
---|
288 | } |
---|
289 | this->usecount--; |
---|
290 | spin_unlock(&jffs2_compressor_list_lock); |
---|
291 | return ret; |
---|
292 | } |
---|
293 | } |
---|
294 | pr_warn("compression type 0x%02x not available\n", comprtype); |
---|
295 | spin_unlock(&jffs2_compressor_list_lock); |
---|
296 | return -EIO; |
---|
297 | } |
---|
298 | return 0; |
---|
299 | } |
---|
300 | |
---|
301 | int jffs2_register_compressor(struct jffs2_compressor *comp) |
---|
302 | { |
---|
303 | struct jffs2_compressor *this; |
---|
304 | |
---|
305 | if (!comp->name) { |
---|
306 | pr_warn("NULL compressor name at registering JFFS2 compressor. Failed.\n"); |
---|
307 | return -1; |
---|
308 | } |
---|
309 | comp->compr_buf_size=0; |
---|
310 | comp->compr_buf=NULL; |
---|
311 | comp->usecount=0; |
---|
312 | comp->stat_compr_orig_size=0; |
---|
313 | comp->stat_compr_new_size=0; |
---|
314 | comp->stat_compr_blocks=0; |
---|
315 | comp->stat_decompr_blocks=0; |
---|
316 | jffs2_dbg(1, "Registering JFFS2 compressor \"%s\"\n", comp->name); |
---|
317 | |
---|
318 | spin_lock(&jffs2_compressor_list_lock); |
---|
319 | |
---|
320 | list_for_each_entry(this, &jffs2_compressor_list, list) { |
---|
321 | if (this->priority < comp->priority) { |
---|
322 | list_add(&comp->list, this->list.prev); |
---|
323 | goto out; |
---|
324 | } |
---|
325 | } |
---|
326 | list_add_tail(&comp->list, &jffs2_compressor_list); |
---|
327 | out: |
---|
328 | D2(list_for_each_entry(this, &jffs2_compressor_list, list) { |
---|
329 | printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority); |
---|
330 | }) |
---|
331 | |
---|
332 | spin_unlock(&jffs2_compressor_list_lock); |
---|
333 | |
---|
334 | return 0; |
---|
335 | } |
---|
336 | |
---|
337 | int jffs2_unregister_compressor(struct jffs2_compressor *comp) |
---|
338 | { |
---|
339 | D2(struct jffs2_compressor *this); |
---|
340 | |
---|
341 | jffs2_dbg(1, "Unregistering JFFS2 compressor \"%s\"\n", comp->name); |
---|
342 | |
---|
343 | spin_lock(&jffs2_compressor_list_lock); |
---|
344 | |
---|
345 | if (comp->usecount) { |
---|
346 | spin_unlock(&jffs2_compressor_list_lock); |
---|
347 | pr_warn("Compressor module is in use. Unregister failed.\n"); |
---|
348 | return -1; |
---|
349 | } |
---|
350 | list_del(&comp->list); |
---|
351 | |
---|
352 | D2(list_for_each_entry(this, &jffs2_compressor_list, list) { |
---|
353 | printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority); |
---|
354 | }) |
---|
355 | spin_unlock(&jffs2_compressor_list_lock); |
---|
356 | return 0; |
---|
357 | } |
---|
358 | |
---|
359 | void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig) |
---|
360 | { |
---|
361 | if (orig != comprbuf) |
---|
362 | kfree(comprbuf); |
---|
363 | } |
---|
364 | |
---|
365 | int __init jffs2_compressors_init(void) |
---|
366 | { |
---|
367 | /* Registering compressors */ |
---|
368 | #ifdef CONFIG_JFFS2_ZLIB |
---|
369 | jffs2_zlib_init(); |
---|
370 | #endif |
---|
371 | #ifdef CONFIG_JFFS2_RTIME |
---|
372 | jffs2_rtime_init(); |
---|
373 | #endif |
---|
374 | #ifdef CONFIG_JFFS2_RUBIN |
---|
375 | jffs2_rubinmips_init(); |
---|
376 | jffs2_dynrubin_init(); |
---|
377 | #endif |
---|
378 | #ifdef CONFIG_JFFS2_LZO |
---|
379 | jffs2_lzo_init(); |
---|
380 | #endif |
---|
381 | /* Setting default compression mode */ |
---|
382 | #ifdef CONFIG_JFFS2_CMODE_NONE |
---|
383 | jffs2_compression_mode = JFFS2_COMPR_MODE_NONE; |
---|
384 | jffs2_dbg(1, "default compression mode: none\n"); |
---|
385 | #else |
---|
386 | #ifdef CONFIG_JFFS2_CMODE_SIZE |
---|
387 | jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE; |
---|
388 | jffs2_dbg(1, "default compression mode: size\n"); |
---|
389 | #else |
---|
390 | #ifdef CONFIG_JFFS2_CMODE_FAVOURLZO |
---|
391 | jffs2_compression_mode = JFFS2_COMPR_MODE_FAVOURLZO; |
---|
392 | jffs2_dbg(1, "default compression mode: favourlzo\n"); |
---|
393 | #else |
---|
394 | jffs2_dbg(1, "default compression mode: priority\n"); |
---|
395 | #endif |
---|
396 | #endif |
---|
397 | #endif |
---|
398 | return 0; |
---|
399 | } |
---|
400 | |
---|
401 | int jffs2_compressors_exit(void) |
---|
402 | { |
---|
403 | /* Unregistering compressors */ |
---|
404 | #ifdef CONFIG_JFFS2_LZO |
---|
405 | jffs2_lzo_exit(); |
---|
406 | #endif |
---|
407 | #ifdef CONFIG_JFFS2_RUBIN |
---|
408 | jffs2_dynrubin_exit(); |
---|
409 | jffs2_rubinmips_exit(); |
---|
410 | #endif |
---|
411 | #ifdef CONFIG_JFFS2_RTIME |
---|
412 | jffs2_rtime_exit(); |
---|
413 | #endif |
---|
414 | #ifdef CONFIG_JFFS2_ZLIB |
---|
415 | jffs2_zlib_exit(); |
---|
416 | #endif |
---|
417 | return 0; |
---|
418 | } |
---|