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c8b97818 CM |
1 | /* |
2 | * Copyright (C) 2008 Oracle. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | * | |
18 | * Based on jffs2 zlib code: | |
19 | * Copyright © 2001-2007 Red Hat, Inc. | |
20 | * Created by David Woodhouse <dwmw2@infradead.org> | |
21 | */ | |
22 | ||
23 | #include <linux/kernel.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/zlib.h> | |
26 | #include <linux/zutil.h> | |
27 | #include <linux/vmalloc.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/err.h> | |
30 | #include <linux/sched.h> | |
31 | #include <linux/pagemap.h> | |
32 | #include <linux/bio.h> | |
b2950863 | 33 | #include "compression.h" |
c8b97818 | 34 | |
c8b97818 CM |
35 | struct workspace { |
36 | z_stream inf_strm; | |
37 | z_stream def_strm; | |
38 | char *buf; | |
39 | struct list_head list; | |
40 | }; | |
41 | ||
261507a0 LZ |
42 | static void zlib_free_workspace(struct list_head *ws) |
43 | { | |
44 | struct workspace *workspace = list_entry(ws, struct workspace, list); | |
c8b97818 | 45 | |
261507a0 LZ |
46 | vfree(workspace->def_strm.workspace); |
47 | vfree(workspace->inf_strm.workspace); | |
48 | kfree(workspace->buf); | |
49 | kfree(workspace); | |
50 | } | |
51 | ||
52 | static struct list_head *zlib_alloc_workspace(void) | |
c8b97818 CM |
53 | { |
54 | struct workspace *workspace; | |
8844355d | 55 | |
c8b97818 | 56 | workspace = kzalloc(sizeof(*workspace), GFP_NOFS); |
261507a0 LZ |
57 | if (!workspace) |
58 | return ERR_PTR(-ENOMEM); | |
c8b97818 CM |
59 | |
60 | workspace->def_strm.workspace = vmalloc(zlib_deflate_workspacesize()); | |
c8b97818 | 61 | workspace->inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); |
c8b97818 | 62 | workspace->buf = kmalloc(PAGE_CACHE_SIZE, GFP_NOFS); |
261507a0 LZ |
63 | if (!workspace->def_strm.workspace || |
64 | !workspace->inf_strm.workspace || !workspace->buf) | |
65 | goto fail; | |
c8b97818 | 66 | |
261507a0 | 67 | INIT_LIST_HEAD(&workspace->list); |
c8b97818 | 68 | |
261507a0 LZ |
69 | return &workspace->list; |
70 | fail: | |
71 | zlib_free_workspace(&workspace->list); | |
72 | return ERR_PTR(-ENOMEM); | |
c8b97818 CM |
73 | } |
74 | ||
261507a0 LZ |
75 | static int zlib_compress_pages(struct list_head *ws, |
76 | struct address_space *mapping, | |
77 | u64 start, unsigned long len, | |
78 | struct page **pages, | |
79 | unsigned long nr_dest_pages, | |
80 | unsigned long *out_pages, | |
81 | unsigned long *total_in, | |
82 | unsigned long *total_out, | |
83 | unsigned long max_out) | |
c8b97818 | 84 | { |
261507a0 | 85 | struct workspace *workspace = list_entry(ws, struct workspace, list); |
c8b97818 | 86 | int ret; |
c8b97818 CM |
87 | char *data_in; |
88 | char *cpage_out; | |
89 | int nr_pages = 0; | |
90 | struct page *in_page = NULL; | |
91 | struct page *out_page = NULL; | |
c8b97818 CM |
92 | unsigned long bytes_left; |
93 | ||
94 | *out_pages = 0; | |
95 | *total_out = 0; | |
96 | *total_in = 0; | |
97 | ||
c8b97818 CM |
98 | if (Z_OK != zlib_deflateInit(&workspace->def_strm, 3)) { |
99 | printk(KERN_WARNING "deflateInit failed\n"); | |
100 | ret = -1; | |
101 | goto out; | |
102 | } | |
103 | ||
104 | workspace->def_strm.total_in = 0; | |
105 | workspace->def_strm.total_out = 0; | |
106 | ||
107 | in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT); | |
108 | data_in = kmap(in_page); | |
109 | ||
110 | out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); | |
4b72029d LZ |
111 | if (out_page == NULL) { |
112 | ret = -1; | |
113 | goto out; | |
114 | } | |
c8b97818 CM |
115 | cpage_out = kmap(out_page); |
116 | pages[0] = out_page; | |
117 | nr_pages = 1; | |
118 | ||
119 | workspace->def_strm.next_in = data_in; | |
120 | workspace->def_strm.next_out = cpage_out; | |
121 | workspace->def_strm.avail_out = PAGE_CACHE_SIZE; | |
122 | workspace->def_strm.avail_in = min(len, PAGE_CACHE_SIZE); | |
123 | ||
c8b97818 CM |
124 | while (workspace->def_strm.total_in < len) { |
125 | ret = zlib_deflate(&workspace->def_strm, Z_SYNC_FLUSH); | |
126 | if (ret != Z_OK) { | |
127 | printk(KERN_DEBUG "btrfs deflate in loop returned %d\n", | |
128 | ret); | |
129 | zlib_deflateEnd(&workspace->def_strm); | |
130 | ret = -1; | |
131 | goto out; | |
132 | } | |
133 | ||
134 | /* we're making it bigger, give up */ | |
135 | if (workspace->def_strm.total_in > 8192 && | |
136 | workspace->def_strm.total_in < | |
137 | workspace->def_strm.total_out) { | |
138 | ret = -1; | |
139 | goto out; | |
140 | } | |
141 | /* we need another page for writing out. Test this | |
142 | * before the total_in so we will pull in a new page for | |
143 | * the stream end if required | |
144 | */ | |
145 | if (workspace->def_strm.avail_out == 0) { | |
146 | kunmap(out_page); | |
147 | if (nr_pages == nr_dest_pages) { | |
148 | out_page = NULL; | |
149 | ret = -1; | |
150 | goto out; | |
151 | } | |
152 | out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); | |
4b72029d LZ |
153 | if (out_page == NULL) { |
154 | ret = -1; | |
155 | goto out; | |
156 | } | |
c8b97818 CM |
157 | cpage_out = kmap(out_page); |
158 | pages[nr_pages] = out_page; | |
159 | nr_pages++; | |
160 | workspace->def_strm.avail_out = PAGE_CACHE_SIZE; | |
161 | workspace->def_strm.next_out = cpage_out; | |
162 | } | |
163 | /* we're all done */ | |
164 | if (workspace->def_strm.total_in >= len) | |
165 | break; | |
166 | ||
167 | /* we've read in a full page, get a new one */ | |
168 | if (workspace->def_strm.avail_in == 0) { | |
169 | if (workspace->def_strm.total_out > max_out) | |
170 | break; | |
171 | ||
172 | bytes_left = len - workspace->def_strm.total_in; | |
173 | kunmap(in_page); | |
174 | page_cache_release(in_page); | |
175 | ||
176 | start += PAGE_CACHE_SIZE; | |
177 | in_page = find_get_page(mapping, | |
178 | start >> PAGE_CACHE_SHIFT); | |
179 | data_in = kmap(in_page); | |
180 | workspace->def_strm.avail_in = min(bytes_left, | |
181 | PAGE_CACHE_SIZE); | |
182 | workspace->def_strm.next_in = data_in; | |
183 | } | |
184 | } | |
185 | workspace->def_strm.avail_in = 0; | |
186 | ret = zlib_deflate(&workspace->def_strm, Z_FINISH); | |
187 | zlib_deflateEnd(&workspace->def_strm); | |
188 | ||
189 | if (ret != Z_STREAM_END) { | |
190 | ret = -1; | |
191 | goto out; | |
192 | } | |
193 | ||
194 | if (workspace->def_strm.total_out >= workspace->def_strm.total_in) { | |
195 | ret = -1; | |
196 | goto out; | |
197 | } | |
198 | ||
199 | ret = 0; | |
200 | *total_out = workspace->def_strm.total_out; | |
201 | *total_in = workspace->def_strm.total_in; | |
202 | out: | |
203 | *out_pages = nr_pages; | |
204 | if (out_page) | |
205 | kunmap(out_page); | |
206 | ||
207 | if (in_page) { | |
208 | kunmap(in_page); | |
209 | page_cache_release(in_page); | |
210 | } | |
c8b97818 CM |
211 | return ret; |
212 | } | |
213 | ||
261507a0 LZ |
214 | static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in, |
215 | u64 disk_start, | |
216 | struct bio_vec *bvec, | |
217 | int vcnt, | |
218 | size_t srclen) | |
c8b97818 | 219 | { |
261507a0 | 220 | struct workspace *workspace = list_entry(ws, struct workspace, list); |
c8b97818 CM |
221 | int ret = 0; |
222 | int wbits = MAX_WBITS; | |
c8b97818 CM |
223 | char *data_in; |
224 | size_t total_out = 0; | |
225 | unsigned long page_bytes_left; | |
226 | unsigned long page_in_index = 0; | |
227 | unsigned long page_out_index = 0; | |
228 | struct page *page_out; | |
229 | unsigned long total_pages_in = (srclen + PAGE_CACHE_SIZE - 1) / | |
230 | PAGE_CACHE_SIZE; | |
231 | unsigned long buf_start; | |
232 | unsigned long buf_offset; | |
233 | unsigned long bytes; | |
234 | unsigned long working_bytes; | |
235 | unsigned long pg_offset; | |
236 | unsigned long start_byte; | |
237 | unsigned long current_buf_start; | |
238 | char *kaddr; | |
239 | ||
c8b97818 CM |
240 | data_in = kmap(pages_in[page_in_index]); |
241 | workspace->inf_strm.next_in = data_in; | |
5b050f04 | 242 | workspace->inf_strm.avail_in = min_t(size_t, srclen, PAGE_CACHE_SIZE); |
c8b97818 CM |
243 | workspace->inf_strm.total_in = 0; |
244 | ||
245 | workspace->inf_strm.total_out = 0; | |
246 | workspace->inf_strm.next_out = workspace->buf; | |
247 | workspace->inf_strm.avail_out = PAGE_CACHE_SIZE; | |
248 | page_out = bvec[page_out_index].bv_page; | |
249 | page_bytes_left = PAGE_CACHE_SIZE; | |
250 | pg_offset = 0; | |
251 | ||
252 | /* If it's deflate, and it's got no preset dictionary, then | |
253 | we can tell zlib to skip the adler32 check. */ | |
254 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && | |
255 | ((data_in[0] & 0x0f) == Z_DEFLATED) && | |
256 | !(((data_in[0]<<8) + data_in[1]) % 31)) { | |
257 | ||
258 | wbits = -((data_in[0] >> 4) + 8); | |
259 | workspace->inf_strm.next_in += 2; | |
260 | workspace->inf_strm.avail_in -= 2; | |
261 | } | |
262 | ||
263 | if (Z_OK != zlib_inflateInit2(&workspace->inf_strm, wbits)) { | |
264 | printk(KERN_WARNING "inflateInit failed\n"); | |
261507a0 | 265 | return -1; |
c8b97818 | 266 | } |
d397712b | 267 | while (workspace->inf_strm.total_in < srclen) { |
c8b97818 | 268 | ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH); |
d397712b | 269 | if (ret != Z_OK && ret != Z_STREAM_END) |
c8b97818 | 270 | break; |
c8b97818 CM |
271 | /* |
272 | * buf start is the byte offset we're of the start of | |
273 | * our workspace buffer | |
274 | */ | |
275 | buf_start = total_out; | |
276 | ||
277 | /* total_out is the last byte of the workspace buffer */ | |
278 | total_out = workspace->inf_strm.total_out; | |
279 | ||
280 | working_bytes = total_out - buf_start; | |
281 | ||
282 | /* | |
283 | * start byte is the first byte of the page we're currently | |
284 | * copying into relative to the start of the compressed data. | |
285 | */ | |
286 | start_byte = page_offset(page_out) - disk_start; | |
287 | ||
288 | if (working_bytes == 0) { | |
289 | /* we didn't make progress in this inflate | |
290 | * call, we're done | |
291 | */ | |
d397712b | 292 | if (ret != Z_STREAM_END) |
c8b97818 CM |
293 | ret = -1; |
294 | break; | |
295 | } | |
296 | ||
297 | /* we haven't yet hit data corresponding to this page */ | |
d397712b | 298 | if (total_out <= start_byte) |
c8b97818 | 299 | goto next; |
c8b97818 CM |
300 | |
301 | /* | |
302 | * the start of the data we care about is offset into | |
303 | * the middle of our working buffer | |
304 | */ | |
305 | if (total_out > start_byte && buf_start < start_byte) { | |
306 | buf_offset = start_byte - buf_start; | |
307 | working_bytes -= buf_offset; | |
308 | } else { | |
309 | buf_offset = 0; | |
310 | } | |
311 | current_buf_start = buf_start; | |
312 | ||
313 | /* copy bytes from the working buffer into the pages */ | |
d397712b | 314 | while (working_bytes > 0) { |
c8b97818 CM |
315 | bytes = min(PAGE_CACHE_SIZE - pg_offset, |
316 | PAGE_CACHE_SIZE - buf_offset); | |
317 | bytes = min(bytes, working_bytes); | |
318 | kaddr = kmap_atomic(page_out, KM_USER0); | |
319 | memcpy(kaddr + pg_offset, workspace->buf + buf_offset, | |
320 | bytes); | |
321 | kunmap_atomic(kaddr, KM_USER0); | |
322 | flush_dcache_page(page_out); | |
323 | ||
324 | pg_offset += bytes; | |
325 | page_bytes_left -= bytes; | |
326 | buf_offset += bytes; | |
327 | working_bytes -= bytes; | |
328 | current_buf_start += bytes; | |
329 | ||
330 | /* check if we need to pick another page */ | |
331 | if (page_bytes_left == 0) { | |
332 | page_out_index++; | |
333 | if (page_out_index >= vcnt) { | |
334 | ret = 0; | |
335 | goto done; | |
336 | } | |
d397712b | 337 | |
c8b97818 CM |
338 | page_out = bvec[page_out_index].bv_page; |
339 | pg_offset = 0; | |
340 | page_bytes_left = PAGE_CACHE_SIZE; | |
341 | start_byte = page_offset(page_out) - disk_start; | |
342 | ||
343 | /* | |
344 | * make sure our new page is covered by this | |
345 | * working buffer | |
346 | */ | |
d397712b | 347 | if (total_out <= start_byte) |
c8b97818 | 348 | goto next; |
c8b97818 CM |
349 | |
350 | /* the next page in the biovec might not | |
351 | * be adjacent to the last page, but it | |
352 | * might still be found inside this working | |
353 | * buffer. bump our offset pointer | |
354 | */ | |
355 | if (total_out > start_byte && | |
356 | current_buf_start < start_byte) { | |
357 | buf_offset = start_byte - buf_start; | |
358 | working_bytes = total_out - start_byte; | |
359 | current_buf_start = buf_start + | |
360 | buf_offset; | |
361 | } | |
362 | } | |
363 | } | |
364 | next: | |
365 | workspace->inf_strm.next_out = workspace->buf; | |
366 | workspace->inf_strm.avail_out = PAGE_CACHE_SIZE; | |
367 | ||
368 | if (workspace->inf_strm.avail_in == 0) { | |
369 | unsigned long tmp; | |
370 | kunmap(pages_in[page_in_index]); | |
371 | page_in_index++; | |
372 | if (page_in_index >= total_pages_in) { | |
373 | data_in = NULL; | |
374 | break; | |
375 | } | |
376 | data_in = kmap(pages_in[page_in_index]); | |
377 | workspace->inf_strm.next_in = data_in; | |
378 | tmp = srclen - workspace->inf_strm.total_in; | |
379 | workspace->inf_strm.avail_in = min(tmp, | |
380 | PAGE_CACHE_SIZE); | |
381 | } | |
382 | } | |
d397712b | 383 | if (ret != Z_STREAM_END) |
c8b97818 | 384 | ret = -1; |
d397712b | 385 | else |
c8b97818 | 386 | ret = 0; |
c8b97818 CM |
387 | done: |
388 | zlib_inflateEnd(&workspace->inf_strm); | |
389 | if (data_in) | |
390 | kunmap(pages_in[page_in_index]); | |
c8b97818 CM |
391 | return ret; |
392 | } | |
393 | ||
261507a0 LZ |
394 | static int zlib_decompress(struct list_head *ws, unsigned char *data_in, |
395 | struct page *dest_page, | |
396 | unsigned long start_byte, | |
397 | size_t srclen, size_t destlen) | |
c8b97818 | 398 | { |
261507a0 | 399 | struct workspace *workspace = list_entry(ws, struct workspace, list); |
c8b97818 CM |
400 | int ret = 0; |
401 | int wbits = MAX_WBITS; | |
c8b97818 CM |
402 | unsigned long bytes_left = destlen; |
403 | unsigned long total_out = 0; | |
404 | char *kaddr; | |
405 | ||
c8b97818 CM |
406 | workspace->inf_strm.next_in = data_in; |
407 | workspace->inf_strm.avail_in = srclen; | |
408 | workspace->inf_strm.total_in = 0; | |
409 | ||
410 | workspace->inf_strm.next_out = workspace->buf; | |
411 | workspace->inf_strm.avail_out = PAGE_CACHE_SIZE; | |
412 | workspace->inf_strm.total_out = 0; | |
413 | /* If it's deflate, and it's got no preset dictionary, then | |
414 | we can tell zlib to skip the adler32 check. */ | |
415 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && | |
416 | ((data_in[0] & 0x0f) == Z_DEFLATED) && | |
417 | !(((data_in[0]<<8) + data_in[1]) % 31)) { | |
418 | ||
419 | wbits = -((data_in[0] >> 4) + 8); | |
420 | workspace->inf_strm.next_in += 2; | |
421 | workspace->inf_strm.avail_in -= 2; | |
422 | } | |
423 | ||
424 | if (Z_OK != zlib_inflateInit2(&workspace->inf_strm, wbits)) { | |
425 | printk(KERN_WARNING "inflateInit failed\n"); | |
261507a0 | 426 | return -1; |
c8b97818 CM |
427 | } |
428 | ||
d397712b | 429 | while (bytes_left > 0) { |
c8b97818 CM |
430 | unsigned long buf_start; |
431 | unsigned long buf_offset; | |
432 | unsigned long bytes; | |
433 | unsigned long pg_offset = 0; | |
434 | ||
435 | ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH); | |
d397712b | 436 | if (ret != Z_OK && ret != Z_STREAM_END) |
c8b97818 | 437 | break; |
c8b97818 CM |
438 | |
439 | buf_start = total_out; | |
440 | total_out = workspace->inf_strm.total_out; | |
441 | ||
442 | if (total_out == buf_start) { | |
443 | ret = -1; | |
444 | break; | |
445 | } | |
446 | ||
d397712b | 447 | if (total_out <= start_byte) |
c8b97818 | 448 | goto next; |
c8b97818 | 449 | |
d397712b | 450 | if (total_out > start_byte && buf_start < start_byte) |
c8b97818 | 451 | buf_offset = start_byte - buf_start; |
d397712b | 452 | else |
c8b97818 | 453 | buf_offset = 0; |
c8b97818 CM |
454 | |
455 | bytes = min(PAGE_CACHE_SIZE - pg_offset, | |
456 | PAGE_CACHE_SIZE - buf_offset); | |
457 | bytes = min(bytes, bytes_left); | |
458 | ||
459 | kaddr = kmap_atomic(dest_page, KM_USER0); | |
460 | memcpy(kaddr + pg_offset, workspace->buf + buf_offset, bytes); | |
461 | kunmap_atomic(kaddr, KM_USER0); | |
462 | ||
463 | pg_offset += bytes; | |
464 | bytes_left -= bytes; | |
465 | next: | |
466 | workspace->inf_strm.next_out = workspace->buf; | |
467 | workspace->inf_strm.avail_out = PAGE_CACHE_SIZE; | |
468 | } | |
d397712b CM |
469 | |
470 | if (ret != Z_STREAM_END && bytes_left != 0) | |
c8b97818 | 471 | ret = -1; |
d397712b | 472 | else |
c8b97818 | 473 | ret = 0; |
d397712b | 474 | |
c8b97818 | 475 | zlib_inflateEnd(&workspace->inf_strm); |
c8b97818 CM |
476 | return ret; |
477 | } | |
478 | ||
261507a0 LZ |
479 | struct btrfs_compress_op btrfs_zlib_compress = { |
480 | .alloc_workspace = zlib_alloc_workspace, | |
481 | .free_workspace = zlib_free_workspace, | |
482 | .compress_pages = zlib_compress_pages, | |
483 | .decompress_biovec = zlib_decompress_biovec, | |
484 | .decompress = zlib_decompress, | |
485 | }; |