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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> | |
e1ddce71 | 33 | #include <linux/refcount.h> |
b2950863 | 34 | #include "compression.h" |
c8b97818 | 35 | |
c8b97818 | 36 | struct workspace { |
78809913 | 37 | z_stream strm; |
c8b97818 CM |
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 | |
78809913 | 46 | vfree(workspace->strm.workspace); |
261507a0 LZ |
47 | kfree(workspace->buf); |
48 | kfree(workspace); | |
49 | } | |
50 | ||
51 | static struct list_head *zlib_alloc_workspace(void) | |
c8b97818 CM |
52 | { |
53 | struct workspace *workspace; | |
78809913 | 54 | int workspacesize; |
8844355d | 55 | |
389a6cfc | 56 | workspace = kzalloc(sizeof(*workspace), GFP_KERNEL); |
261507a0 LZ |
57 | if (!workspace) |
58 | return ERR_PTR(-ENOMEM); | |
c8b97818 | 59 | |
78809913 SS |
60 | workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL), |
61 | zlib_inflate_workspacesize()); | |
62 | workspace->strm.workspace = vmalloc(workspacesize); | |
389a6cfc | 63 | workspace->buf = kmalloc(PAGE_SIZE, GFP_KERNEL); |
78809913 | 64 | if (!workspace->strm.workspace || !workspace->buf) |
261507a0 | 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, | |
38c31464 | 77 | u64 start, |
261507a0 | 78 | struct page **pages, |
261507a0 LZ |
79 | unsigned long *out_pages, |
80 | unsigned long *total_in, | |
e5d74902 | 81 | unsigned long *total_out) |
c8b97818 | 82 | { |
261507a0 | 83 | struct workspace *workspace = list_entry(ws, struct workspace, list); |
c8b97818 | 84 | int ret; |
c8b97818 CM |
85 | char *data_in; |
86 | char *cpage_out; | |
87 | int nr_pages = 0; | |
88 | struct page *in_page = NULL; | |
89 | struct page *out_page = NULL; | |
c8b97818 | 90 | unsigned long bytes_left; |
38c31464 | 91 | unsigned long len = *total_out; |
4d3a800e | 92 | unsigned long nr_dest_pages = *out_pages; |
e5d74902 | 93 | const unsigned long max_out = nr_dest_pages * PAGE_SIZE; |
c8b97818 CM |
94 | |
95 | *out_pages = 0; | |
96 | *total_out = 0; | |
97 | *total_in = 0; | |
98 | ||
78809913 | 99 | if (Z_OK != zlib_deflateInit(&workspace->strm, 3)) { |
62e85577 | 100 | pr_warn("BTRFS: deflateInit failed\n"); |
60e1975a | 101 | ret = -EIO; |
c8b97818 CM |
102 | goto out; |
103 | } | |
104 | ||
78809913 SS |
105 | workspace->strm.total_in = 0; |
106 | workspace->strm.total_out = 0; | |
c8b97818 | 107 | |
09cbfeaf | 108 | in_page = find_get_page(mapping, start >> PAGE_SHIFT); |
c8b97818 CM |
109 | data_in = kmap(in_page); |
110 | ||
111 | out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); | |
4b72029d | 112 | if (out_page == NULL) { |
60e1975a | 113 | ret = -ENOMEM; |
4b72029d LZ |
114 | goto out; |
115 | } | |
c8b97818 CM |
116 | cpage_out = kmap(out_page); |
117 | pages[0] = out_page; | |
118 | nr_pages = 1; | |
119 | ||
78809913 SS |
120 | workspace->strm.next_in = data_in; |
121 | workspace->strm.next_out = cpage_out; | |
09cbfeaf KS |
122 | workspace->strm.avail_out = PAGE_SIZE; |
123 | workspace->strm.avail_in = min(len, PAGE_SIZE); | |
c8b97818 | 124 | |
78809913 SS |
125 | while (workspace->strm.total_in < len) { |
126 | ret = zlib_deflate(&workspace->strm, Z_SYNC_FLUSH); | |
c8b97818 | 127 | if (ret != Z_OK) { |
62e85577 | 128 | pr_debug("BTRFS: deflate in loop returned %d\n", |
c8b97818 | 129 | ret); |
78809913 | 130 | zlib_deflateEnd(&workspace->strm); |
60e1975a | 131 | ret = -EIO; |
c8b97818 CM |
132 | goto out; |
133 | } | |
134 | ||
135 | /* we're making it bigger, give up */ | |
78809913 SS |
136 | if (workspace->strm.total_in > 8192 && |
137 | workspace->strm.total_in < | |
138 | workspace->strm.total_out) { | |
130d5b41 | 139 | ret = -E2BIG; |
c8b97818 CM |
140 | goto out; |
141 | } | |
142 | /* we need another page for writing out. Test this | |
143 | * before the total_in so we will pull in a new page for | |
144 | * the stream end if required | |
145 | */ | |
78809913 | 146 | if (workspace->strm.avail_out == 0) { |
c8b97818 CM |
147 | kunmap(out_page); |
148 | if (nr_pages == nr_dest_pages) { | |
149 | out_page = NULL; | |
60e1975a | 150 | ret = -E2BIG; |
c8b97818 CM |
151 | goto out; |
152 | } | |
153 | out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); | |
4b72029d | 154 | if (out_page == NULL) { |
60e1975a | 155 | ret = -ENOMEM; |
4b72029d LZ |
156 | goto out; |
157 | } | |
c8b97818 CM |
158 | cpage_out = kmap(out_page); |
159 | pages[nr_pages] = out_page; | |
160 | nr_pages++; | |
09cbfeaf | 161 | workspace->strm.avail_out = PAGE_SIZE; |
78809913 | 162 | workspace->strm.next_out = cpage_out; |
c8b97818 CM |
163 | } |
164 | /* we're all done */ | |
78809913 | 165 | if (workspace->strm.total_in >= len) |
c8b97818 CM |
166 | break; |
167 | ||
168 | /* we've read in a full page, get a new one */ | |
78809913 SS |
169 | if (workspace->strm.avail_in == 0) { |
170 | if (workspace->strm.total_out > max_out) | |
c8b97818 CM |
171 | break; |
172 | ||
78809913 | 173 | bytes_left = len - workspace->strm.total_in; |
c8b97818 | 174 | kunmap(in_page); |
09cbfeaf | 175 | put_page(in_page); |
c8b97818 | 176 | |
09cbfeaf | 177 | start += PAGE_SIZE; |
c8b97818 | 178 | in_page = find_get_page(mapping, |
09cbfeaf | 179 | start >> PAGE_SHIFT); |
c8b97818 | 180 | data_in = kmap(in_page); |
78809913 | 181 | workspace->strm.avail_in = min(bytes_left, |
09cbfeaf | 182 | PAGE_SIZE); |
78809913 | 183 | workspace->strm.next_in = data_in; |
c8b97818 CM |
184 | } |
185 | } | |
78809913 SS |
186 | workspace->strm.avail_in = 0; |
187 | ret = zlib_deflate(&workspace->strm, Z_FINISH); | |
188 | zlib_deflateEnd(&workspace->strm); | |
c8b97818 CM |
189 | |
190 | if (ret != Z_STREAM_END) { | |
60e1975a | 191 | ret = -EIO; |
c8b97818 CM |
192 | goto out; |
193 | } | |
194 | ||
78809913 | 195 | if (workspace->strm.total_out >= workspace->strm.total_in) { |
60e1975a | 196 | ret = -E2BIG; |
c8b97818 CM |
197 | goto out; |
198 | } | |
199 | ||
200 | ret = 0; | |
78809913 SS |
201 | *total_out = workspace->strm.total_out; |
202 | *total_in = workspace->strm.total_in; | |
c8b97818 CM |
203 | out: |
204 | *out_pages = nr_pages; | |
205 | if (out_page) | |
206 | kunmap(out_page); | |
207 | ||
208 | if (in_page) { | |
209 | kunmap(in_page); | |
09cbfeaf | 210 | put_page(in_page); |
c8b97818 | 211 | } |
c8b97818 CM |
212 | return ret; |
213 | } | |
214 | ||
e1ddce71 | 215 | static int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb) |
c8b97818 | 216 | { |
261507a0 | 217 | struct workspace *workspace = list_entry(ws, struct workspace, list); |
3a39c18d | 218 | int ret = 0, ret2; |
c8b97818 | 219 | int wbits = MAX_WBITS; |
c8b97818 CM |
220 | char *data_in; |
221 | size_t total_out = 0; | |
c8b97818 | 222 | unsigned long page_in_index = 0; |
e1ddce71 | 223 | size_t srclen = cb->compressed_len; |
09cbfeaf | 224 | unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE); |
c8b97818 | 225 | unsigned long buf_start; |
e1ddce71 AJ |
226 | struct page **pages_in = cb->compressed_pages; |
227 | u64 disk_start = cb->start; | |
228 | struct bio *orig_bio = cb->orig_bio; | |
c8b97818 | 229 | |
c8b97818 | 230 | data_in = kmap(pages_in[page_in_index]); |
78809913 | 231 | workspace->strm.next_in = data_in; |
09cbfeaf | 232 | workspace->strm.avail_in = min_t(size_t, srclen, PAGE_SIZE); |
78809913 | 233 | workspace->strm.total_in = 0; |
c8b97818 | 234 | |
78809913 SS |
235 | workspace->strm.total_out = 0; |
236 | workspace->strm.next_out = workspace->buf; | |
09cbfeaf | 237 | workspace->strm.avail_out = PAGE_SIZE; |
c8b97818 CM |
238 | |
239 | /* If it's deflate, and it's got no preset dictionary, then | |
240 | we can tell zlib to skip the adler32 check. */ | |
241 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && | |
242 | ((data_in[0] & 0x0f) == Z_DEFLATED) && | |
243 | !(((data_in[0]<<8) + data_in[1]) % 31)) { | |
244 | ||
245 | wbits = -((data_in[0] >> 4) + 8); | |
78809913 SS |
246 | workspace->strm.next_in += 2; |
247 | workspace->strm.avail_in -= 2; | |
c8b97818 CM |
248 | } |
249 | ||
78809913 | 250 | if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) { |
62e85577 | 251 | pr_warn("BTRFS: inflateInit failed\n"); |
d1111a75 | 252 | kunmap(pages_in[page_in_index]); |
60e1975a | 253 | return -EIO; |
c8b97818 | 254 | } |
78809913 SS |
255 | while (workspace->strm.total_in < srclen) { |
256 | ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH); | |
d397712b | 257 | if (ret != Z_OK && ret != Z_STREAM_END) |
c8b97818 | 258 | break; |
c8b97818 | 259 | |
3a39c18d | 260 | buf_start = total_out; |
78809913 | 261 | total_out = workspace->strm.total_out; |
c8b97818 | 262 | |
3a39c18d LZ |
263 | /* we didn't make progress in this inflate call, we're done */ |
264 | if (buf_start == total_out) | |
c8b97818 | 265 | break; |
c8b97818 | 266 | |
3a39c18d LZ |
267 | ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start, |
268 | total_out, disk_start, | |
974b1adc | 269 | orig_bio); |
3a39c18d LZ |
270 | if (ret2 == 0) { |
271 | ret = 0; | |
272 | goto done; | |
c8b97818 | 273 | } |
3a39c18d | 274 | |
78809913 | 275 | workspace->strm.next_out = workspace->buf; |
09cbfeaf | 276 | workspace->strm.avail_out = PAGE_SIZE; |
c8b97818 | 277 | |
78809913 | 278 | if (workspace->strm.avail_in == 0) { |
c8b97818 CM |
279 | unsigned long tmp; |
280 | kunmap(pages_in[page_in_index]); | |
281 | page_in_index++; | |
282 | if (page_in_index >= total_pages_in) { | |
283 | data_in = NULL; | |
284 | break; | |
285 | } | |
286 | data_in = kmap(pages_in[page_in_index]); | |
78809913 SS |
287 | workspace->strm.next_in = data_in; |
288 | tmp = srclen - workspace->strm.total_in; | |
289 | workspace->strm.avail_in = min(tmp, | |
09cbfeaf | 290 | PAGE_SIZE); |
c8b97818 CM |
291 | } |
292 | } | |
d397712b | 293 | if (ret != Z_STREAM_END) |
60e1975a | 294 | ret = -EIO; |
d397712b | 295 | else |
c8b97818 | 296 | ret = 0; |
c8b97818 | 297 | done: |
78809913 | 298 | zlib_inflateEnd(&workspace->strm); |
c8b97818 CM |
299 | if (data_in) |
300 | kunmap(pages_in[page_in_index]); | |
2f19cad9 | 301 | if (!ret) |
974b1adc | 302 | zero_fill_bio(orig_bio); |
c8b97818 CM |
303 | return ret; |
304 | } | |
305 | ||
261507a0 LZ |
306 | static int zlib_decompress(struct list_head *ws, unsigned char *data_in, |
307 | struct page *dest_page, | |
308 | unsigned long start_byte, | |
309 | size_t srclen, size_t destlen) | |
c8b97818 | 310 | { |
261507a0 | 311 | struct workspace *workspace = list_entry(ws, struct workspace, list); |
c8b97818 CM |
312 | int ret = 0; |
313 | int wbits = MAX_WBITS; | |
2f19cad9 | 314 | unsigned long bytes_left; |
c8b97818 | 315 | unsigned long total_out = 0; |
2f19cad9 | 316 | unsigned long pg_offset = 0; |
c8b97818 CM |
317 | char *kaddr; |
318 | ||
2f19cad9 CM |
319 | destlen = min_t(unsigned long, destlen, PAGE_SIZE); |
320 | bytes_left = destlen; | |
321 | ||
78809913 SS |
322 | workspace->strm.next_in = data_in; |
323 | workspace->strm.avail_in = srclen; | |
324 | workspace->strm.total_in = 0; | |
c8b97818 | 325 | |
78809913 | 326 | workspace->strm.next_out = workspace->buf; |
09cbfeaf | 327 | workspace->strm.avail_out = PAGE_SIZE; |
78809913 | 328 | workspace->strm.total_out = 0; |
c8b97818 CM |
329 | /* If it's deflate, and it's got no preset dictionary, then |
330 | we can tell zlib to skip the adler32 check. */ | |
331 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && | |
332 | ((data_in[0] & 0x0f) == Z_DEFLATED) && | |
333 | !(((data_in[0]<<8) + data_in[1]) % 31)) { | |
334 | ||
335 | wbits = -((data_in[0] >> 4) + 8); | |
78809913 SS |
336 | workspace->strm.next_in += 2; |
337 | workspace->strm.avail_in -= 2; | |
c8b97818 CM |
338 | } |
339 | ||
78809913 | 340 | if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) { |
62e85577 | 341 | pr_warn("BTRFS: inflateInit failed\n"); |
60e1975a | 342 | return -EIO; |
c8b97818 CM |
343 | } |
344 | ||
d397712b | 345 | while (bytes_left > 0) { |
c8b97818 CM |
346 | unsigned long buf_start; |
347 | unsigned long buf_offset; | |
348 | unsigned long bytes; | |
c8b97818 | 349 | |
78809913 | 350 | ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH); |
d397712b | 351 | if (ret != Z_OK && ret != Z_STREAM_END) |
c8b97818 | 352 | break; |
c8b97818 CM |
353 | |
354 | buf_start = total_out; | |
78809913 | 355 | total_out = workspace->strm.total_out; |
c8b97818 CM |
356 | |
357 | if (total_out == buf_start) { | |
60e1975a | 358 | ret = -EIO; |
c8b97818 CM |
359 | break; |
360 | } | |
361 | ||
d397712b | 362 | if (total_out <= start_byte) |
c8b97818 | 363 | goto next; |
c8b97818 | 364 | |
d397712b | 365 | if (total_out > start_byte && buf_start < start_byte) |
c8b97818 | 366 | buf_offset = start_byte - buf_start; |
d397712b | 367 | else |
c8b97818 | 368 | buf_offset = 0; |
c8b97818 | 369 | |
09cbfeaf KS |
370 | bytes = min(PAGE_SIZE - pg_offset, |
371 | PAGE_SIZE - buf_offset); | |
c8b97818 CM |
372 | bytes = min(bytes, bytes_left); |
373 | ||
7ac687d9 | 374 | kaddr = kmap_atomic(dest_page); |
c8b97818 | 375 | memcpy(kaddr + pg_offset, workspace->buf + buf_offset, bytes); |
7ac687d9 | 376 | kunmap_atomic(kaddr); |
c8b97818 CM |
377 | |
378 | pg_offset += bytes; | |
379 | bytes_left -= bytes; | |
380 | next: | |
78809913 | 381 | workspace->strm.next_out = workspace->buf; |
09cbfeaf | 382 | workspace->strm.avail_out = PAGE_SIZE; |
c8b97818 | 383 | } |
d397712b CM |
384 | |
385 | if (ret != Z_STREAM_END && bytes_left != 0) | |
60e1975a | 386 | ret = -EIO; |
d397712b | 387 | else |
c8b97818 | 388 | ret = 0; |
d397712b | 389 | |
78809913 | 390 | zlib_inflateEnd(&workspace->strm); |
2f19cad9 CM |
391 | |
392 | /* | |
393 | * this should only happen if zlib returned fewer bytes than we | |
394 | * expected. btrfs_get_block is responsible for zeroing from the | |
395 | * end of the inline extent (destlen) to the end of the page | |
396 | */ | |
397 | if (pg_offset < destlen) { | |
398 | kaddr = kmap_atomic(dest_page); | |
399 | memset(kaddr + pg_offset, 0, destlen - pg_offset); | |
400 | kunmap_atomic(kaddr); | |
401 | } | |
c8b97818 CM |
402 | return ret; |
403 | } | |
404 | ||
e8c9f186 | 405 | const struct btrfs_compress_op btrfs_zlib_compress = { |
261507a0 LZ |
406 | .alloc_workspace = zlib_alloc_workspace, |
407 | .free_workspace = zlib_free_workspace, | |
408 | .compress_pages = zlib_compress_pages, | |
974b1adc | 409 | .decompress_bio = zlib_decompress_bio, |
261507a0 LZ |
410 | .decompress = zlib_decompress, |
411 | }; |