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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 | 35 | struct workspace { |
78809913 | 36 | z_stream strm; |
c8b97818 CM |
37 | char *buf; |
38 | struct list_head list; | |
39 | }; | |
40 | ||
261507a0 LZ |
41 | static void zlib_free_workspace(struct list_head *ws) |
42 | { | |
43 | struct workspace *workspace = list_entry(ws, struct workspace, list); | |
c8b97818 | 44 | |
78809913 | 45 | vfree(workspace->strm.workspace); |
261507a0 LZ |
46 | kfree(workspace->buf); |
47 | kfree(workspace); | |
48 | } | |
49 | ||
50 | static struct list_head *zlib_alloc_workspace(void) | |
c8b97818 CM |
51 | { |
52 | struct workspace *workspace; | |
78809913 | 53 | int workspacesize; |
8844355d | 54 | |
c8b97818 | 55 | workspace = kzalloc(sizeof(*workspace), GFP_NOFS); |
261507a0 LZ |
56 | if (!workspace) |
57 | return ERR_PTR(-ENOMEM); | |
c8b97818 | 58 | |
78809913 SS |
59 | workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL), |
60 | zlib_inflate_workspacesize()); | |
61 | workspace->strm.workspace = vmalloc(workspacesize); | |
09cbfeaf | 62 | workspace->buf = kmalloc(PAGE_SIZE, GFP_NOFS); |
78809913 | 63 | if (!workspace->strm.workspace || !workspace->buf) |
261507a0 | 64 | goto fail; |
c8b97818 | 65 | |
261507a0 | 66 | INIT_LIST_HEAD(&workspace->list); |
c8b97818 | 67 | |
261507a0 LZ |
68 | return &workspace->list; |
69 | fail: | |
70 | zlib_free_workspace(&workspace->list); | |
71 | return ERR_PTR(-ENOMEM); | |
c8b97818 CM |
72 | } |
73 | ||
261507a0 LZ |
74 | static int zlib_compress_pages(struct list_head *ws, |
75 | struct address_space *mapping, | |
38c31464 | 76 | u64 start, |
261507a0 LZ |
77 | struct page **pages, |
78 | unsigned long nr_dest_pages, | |
79 | unsigned long *out_pages, | |
80 | unsigned long *total_in, | |
81 | unsigned long *total_out, | |
82 | unsigned long max_out) | |
c8b97818 | 83 | { |
261507a0 | 84 | struct workspace *workspace = list_entry(ws, struct workspace, list); |
c8b97818 | 85 | int ret; |
c8b97818 CM |
86 | char *data_in; |
87 | char *cpage_out; | |
88 | int nr_pages = 0; | |
89 | struct page *in_page = NULL; | |
90 | struct page *out_page = NULL; | |
c8b97818 | 91 | unsigned long bytes_left; |
38c31464 | 92 | unsigned long len = *total_out; |
c8b97818 CM |
93 | |
94 | *out_pages = 0; | |
95 | *total_out = 0; | |
96 | *total_in = 0; | |
97 | ||
78809913 | 98 | if (Z_OK != zlib_deflateInit(&workspace->strm, 3)) { |
62e85577 | 99 | pr_warn("BTRFS: deflateInit failed\n"); |
60e1975a | 100 | ret = -EIO; |
c8b97818 CM |
101 | goto out; |
102 | } | |
103 | ||
78809913 SS |
104 | workspace->strm.total_in = 0; |
105 | workspace->strm.total_out = 0; | |
c8b97818 | 106 | |
09cbfeaf | 107 | in_page = find_get_page(mapping, start >> PAGE_SHIFT); |
c8b97818 CM |
108 | data_in = kmap(in_page); |
109 | ||
110 | out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); | |
4b72029d | 111 | if (out_page == NULL) { |
60e1975a | 112 | ret = -ENOMEM; |
4b72029d LZ |
113 | goto out; |
114 | } | |
c8b97818 CM |
115 | cpage_out = kmap(out_page); |
116 | pages[0] = out_page; | |
117 | nr_pages = 1; | |
118 | ||
78809913 SS |
119 | workspace->strm.next_in = data_in; |
120 | workspace->strm.next_out = cpage_out; | |
09cbfeaf KS |
121 | workspace->strm.avail_out = PAGE_SIZE; |
122 | workspace->strm.avail_in = min(len, PAGE_SIZE); | |
c8b97818 | 123 | |
78809913 SS |
124 | while (workspace->strm.total_in < len) { |
125 | ret = zlib_deflate(&workspace->strm, Z_SYNC_FLUSH); | |
c8b97818 | 126 | if (ret != Z_OK) { |
62e85577 | 127 | pr_debug("BTRFS: deflate in loop returned %d\n", |
c8b97818 | 128 | ret); |
78809913 | 129 | zlib_deflateEnd(&workspace->strm); |
60e1975a | 130 | ret = -EIO; |
c8b97818 CM |
131 | goto out; |
132 | } | |
133 | ||
134 | /* we're making it bigger, give up */ | |
78809913 SS |
135 | if (workspace->strm.total_in > 8192 && |
136 | workspace->strm.total_in < | |
137 | workspace->strm.total_out) { | |
130d5b41 | 138 | ret = -E2BIG; |
c8b97818 CM |
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 | */ | |
78809913 | 145 | if (workspace->strm.avail_out == 0) { |
c8b97818 CM |
146 | kunmap(out_page); |
147 | if (nr_pages == nr_dest_pages) { | |
148 | out_page = NULL; | |
60e1975a | 149 | ret = -E2BIG; |
c8b97818 CM |
150 | goto out; |
151 | } | |
152 | out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); | |
4b72029d | 153 | if (out_page == NULL) { |
60e1975a | 154 | ret = -ENOMEM; |
4b72029d LZ |
155 | goto out; |
156 | } | |
c8b97818 CM |
157 | cpage_out = kmap(out_page); |
158 | pages[nr_pages] = out_page; | |
159 | nr_pages++; | |
09cbfeaf | 160 | workspace->strm.avail_out = PAGE_SIZE; |
78809913 | 161 | workspace->strm.next_out = cpage_out; |
c8b97818 CM |
162 | } |
163 | /* we're all done */ | |
78809913 | 164 | if (workspace->strm.total_in >= len) |
c8b97818 CM |
165 | break; |
166 | ||
167 | /* we've read in a full page, get a new one */ | |
78809913 SS |
168 | if (workspace->strm.avail_in == 0) { |
169 | if (workspace->strm.total_out > max_out) | |
c8b97818 CM |
170 | break; |
171 | ||
78809913 | 172 | bytes_left = len - workspace->strm.total_in; |
c8b97818 | 173 | kunmap(in_page); |
09cbfeaf | 174 | put_page(in_page); |
c8b97818 | 175 | |
09cbfeaf | 176 | start += PAGE_SIZE; |
c8b97818 | 177 | in_page = find_get_page(mapping, |
09cbfeaf | 178 | start >> PAGE_SHIFT); |
c8b97818 | 179 | data_in = kmap(in_page); |
78809913 | 180 | workspace->strm.avail_in = min(bytes_left, |
09cbfeaf | 181 | PAGE_SIZE); |
78809913 | 182 | workspace->strm.next_in = data_in; |
c8b97818 CM |
183 | } |
184 | } | |
78809913 SS |
185 | workspace->strm.avail_in = 0; |
186 | ret = zlib_deflate(&workspace->strm, Z_FINISH); | |
187 | zlib_deflateEnd(&workspace->strm); | |
c8b97818 CM |
188 | |
189 | if (ret != Z_STREAM_END) { | |
60e1975a | 190 | ret = -EIO; |
c8b97818 CM |
191 | goto out; |
192 | } | |
193 | ||
78809913 | 194 | if (workspace->strm.total_out >= workspace->strm.total_in) { |
60e1975a | 195 | ret = -E2BIG; |
c8b97818 CM |
196 | goto out; |
197 | } | |
198 | ||
199 | ret = 0; | |
78809913 SS |
200 | *total_out = workspace->strm.total_out; |
201 | *total_in = workspace->strm.total_in; | |
c8b97818 CM |
202 | out: |
203 | *out_pages = nr_pages; | |
204 | if (out_page) | |
205 | kunmap(out_page); | |
206 | ||
207 | if (in_page) { | |
208 | kunmap(in_page); | |
09cbfeaf | 209 | put_page(in_page); |
c8b97818 | 210 | } |
c8b97818 CM |
211 | return ret; |
212 | } | |
213 | ||
974b1adc | 214 | static int zlib_decompress_bio(struct list_head *ws, struct page **pages_in, |
261507a0 | 215 | u64 disk_start, |
974b1adc | 216 | struct bio *orig_bio, |
261507a0 | 217 | size_t srclen) |
c8b97818 | 218 | { |
261507a0 | 219 | struct workspace *workspace = list_entry(ws, struct workspace, list); |
3a39c18d | 220 | int ret = 0, ret2; |
c8b97818 | 221 | int wbits = MAX_WBITS; |
c8b97818 CM |
222 | char *data_in; |
223 | size_t total_out = 0; | |
c8b97818 | 224 | unsigned long page_in_index = 0; |
09cbfeaf | 225 | unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_SIZE); |
c8b97818 | 226 | unsigned long buf_start; |
c8b97818 | 227 | |
c8b97818 | 228 | data_in = kmap(pages_in[page_in_index]); |
78809913 | 229 | workspace->strm.next_in = data_in; |
09cbfeaf | 230 | workspace->strm.avail_in = min_t(size_t, srclen, PAGE_SIZE); |
78809913 | 231 | workspace->strm.total_in = 0; |
c8b97818 | 232 | |
78809913 SS |
233 | workspace->strm.total_out = 0; |
234 | workspace->strm.next_out = workspace->buf; | |
09cbfeaf | 235 | workspace->strm.avail_out = PAGE_SIZE; |
c8b97818 CM |
236 | |
237 | /* If it's deflate, and it's got no preset dictionary, then | |
238 | we can tell zlib to skip the adler32 check. */ | |
239 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && | |
240 | ((data_in[0] & 0x0f) == Z_DEFLATED) && | |
241 | !(((data_in[0]<<8) + data_in[1]) % 31)) { | |
242 | ||
243 | wbits = -((data_in[0] >> 4) + 8); | |
78809913 SS |
244 | workspace->strm.next_in += 2; |
245 | workspace->strm.avail_in -= 2; | |
c8b97818 CM |
246 | } |
247 | ||
78809913 | 248 | if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) { |
62e85577 | 249 | pr_warn("BTRFS: inflateInit failed\n"); |
d1111a75 | 250 | kunmap(pages_in[page_in_index]); |
60e1975a | 251 | return -EIO; |
c8b97818 | 252 | } |
78809913 SS |
253 | while (workspace->strm.total_in < srclen) { |
254 | ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH); | |
d397712b | 255 | if (ret != Z_OK && ret != Z_STREAM_END) |
c8b97818 | 256 | break; |
c8b97818 | 257 | |
3a39c18d | 258 | buf_start = total_out; |
78809913 | 259 | total_out = workspace->strm.total_out; |
c8b97818 | 260 | |
3a39c18d LZ |
261 | /* we didn't make progress in this inflate call, we're done */ |
262 | if (buf_start == total_out) | |
c8b97818 | 263 | break; |
c8b97818 | 264 | |
3a39c18d LZ |
265 | ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start, |
266 | total_out, disk_start, | |
974b1adc | 267 | orig_bio); |
3a39c18d LZ |
268 | if (ret2 == 0) { |
269 | ret = 0; | |
270 | goto done; | |
c8b97818 | 271 | } |
3a39c18d | 272 | |
78809913 | 273 | workspace->strm.next_out = workspace->buf; |
09cbfeaf | 274 | workspace->strm.avail_out = PAGE_SIZE; |
c8b97818 | 275 | |
78809913 | 276 | if (workspace->strm.avail_in == 0) { |
c8b97818 CM |
277 | unsigned long tmp; |
278 | kunmap(pages_in[page_in_index]); | |
279 | page_in_index++; | |
280 | if (page_in_index >= total_pages_in) { | |
281 | data_in = NULL; | |
282 | break; | |
283 | } | |
284 | data_in = kmap(pages_in[page_in_index]); | |
78809913 SS |
285 | workspace->strm.next_in = data_in; |
286 | tmp = srclen - workspace->strm.total_in; | |
287 | workspace->strm.avail_in = min(tmp, | |
09cbfeaf | 288 | PAGE_SIZE); |
c8b97818 CM |
289 | } |
290 | } | |
d397712b | 291 | if (ret != Z_STREAM_END) |
60e1975a | 292 | ret = -EIO; |
d397712b | 293 | else |
c8b97818 | 294 | ret = 0; |
c8b97818 | 295 | done: |
78809913 | 296 | zlib_inflateEnd(&workspace->strm); |
c8b97818 CM |
297 | if (data_in) |
298 | kunmap(pages_in[page_in_index]); | |
2f19cad9 | 299 | if (!ret) |
974b1adc | 300 | zero_fill_bio(orig_bio); |
c8b97818 CM |
301 | return ret; |
302 | } | |
303 | ||
261507a0 LZ |
304 | static int zlib_decompress(struct list_head *ws, unsigned char *data_in, |
305 | struct page *dest_page, | |
306 | unsigned long start_byte, | |
307 | size_t srclen, size_t destlen) | |
c8b97818 | 308 | { |
261507a0 | 309 | struct workspace *workspace = list_entry(ws, struct workspace, list); |
c8b97818 CM |
310 | int ret = 0; |
311 | int wbits = MAX_WBITS; | |
2f19cad9 | 312 | unsigned long bytes_left; |
c8b97818 | 313 | unsigned long total_out = 0; |
2f19cad9 | 314 | unsigned long pg_offset = 0; |
c8b97818 CM |
315 | char *kaddr; |
316 | ||
2f19cad9 CM |
317 | destlen = min_t(unsigned long, destlen, PAGE_SIZE); |
318 | bytes_left = destlen; | |
319 | ||
78809913 SS |
320 | workspace->strm.next_in = data_in; |
321 | workspace->strm.avail_in = srclen; | |
322 | workspace->strm.total_in = 0; | |
c8b97818 | 323 | |
78809913 | 324 | workspace->strm.next_out = workspace->buf; |
09cbfeaf | 325 | workspace->strm.avail_out = PAGE_SIZE; |
78809913 | 326 | workspace->strm.total_out = 0; |
c8b97818 CM |
327 | /* If it's deflate, and it's got no preset dictionary, then |
328 | we can tell zlib to skip the adler32 check. */ | |
329 | if (srclen > 2 && !(data_in[1] & PRESET_DICT) && | |
330 | ((data_in[0] & 0x0f) == Z_DEFLATED) && | |
331 | !(((data_in[0]<<8) + data_in[1]) % 31)) { | |
332 | ||
333 | wbits = -((data_in[0] >> 4) + 8); | |
78809913 SS |
334 | workspace->strm.next_in += 2; |
335 | workspace->strm.avail_in -= 2; | |
c8b97818 CM |
336 | } |
337 | ||
78809913 | 338 | if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) { |
62e85577 | 339 | pr_warn("BTRFS: inflateInit failed\n"); |
60e1975a | 340 | return -EIO; |
c8b97818 CM |
341 | } |
342 | ||
d397712b | 343 | while (bytes_left > 0) { |
c8b97818 CM |
344 | unsigned long buf_start; |
345 | unsigned long buf_offset; | |
346 | unsigned long bytes; | |
c8b97818 | 347 | |
78809913 | 348 | ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH); |
d397712b | 349 | if (ret != Z_OK && ret != Z_STREAM_END) |
c8b97818 | 350 | break; |
c8b97818 CM |
351 | |
352 | buf_start = total_out; | |
78809913 | 353 | total_out = workspace->strm.total_out; |
c8b97818 CM |
354 | |
355 | if (total_out == buf_start) { | |
60e1975a | 356 | ret = -EIO; |
c8b97818 CM |
357 | break; |
358 | } | |
359 | ||
d397712b | 360 | if (total_out <= start_byte) |
c8b97818 | 361 | goto next; |
c8b97818 | 362 | |
d397712b | 363 | if (total_out > start_byte && buf_start < start_byte) |
c8b97818 | 364 | buf_offset = start_byte - buf_start; |
d397712b | 365 | else |
c8b97818 | 366 | buf_offset = 0; |
c8b97818 | 367 | |
09cbfeaf KS |
368 | bytes = min(PAGE_SIZE - pg_offset, |
369 | PAGE_SIZE - buf_offset); | |
c8b97818 CM |
370 | bytes = min(bytes, bytes_left); |
371 | ||
7ac687d9 | 372 | kaddr = kmap_atomic(dest_page); |
c8b97818 | 373 | memcpy(kaddr + pg_offset, workspace->buf + buf_offset, bytes); |
7ac687d9 | 374 | kunmap_atomic(kaddr); |
c8b97818 CM |
375 | |
376 | pg_offset += bytes; | |
377 | bytes_left -= bytes; | |
378 | next: | |
78809913 | 379 | workspace->strm.next_out = workspace->buf; |
09cbfeaf | 380 | workspace->strm.avail_out = PAGE_SIZE; |
c8b97818 | 381 | } |
d397712b CM |
382 | |
383 | if (ret != Z_STREAM_END && bytes_left != 0) | |
60e1975a | 384 | ret = -EIO; |
d397712b | 385 | else |
c8b97818 | 386 | ret = 0; |
d397712b | 387 | |
78809913 | 388 | zlib_inflateEnd(&workspace->strm); |
2f19cad9 CM |
389 | |
390 | /* | |
391 | * this should only happen if zlib returned fewer bytes than we | |
392 | * expected. btrfs_get_block is responsible for zeroing from the | |
393 | * end of the inline extent (destlen) to the end of the page | |
394 | */ | |
395 | if (pg_offset < destlen) { | |
396 | kaddr = kmap_atomic(dest_page); | |
397 | memset(kaddr + pg_offset, 0, destlen - pg_offset); | |
398 | kunmap_atomic(kaddr); | |
399 | } | |
c8b97818 CM |
400 | return ret; |
401 | } | |
402 | ||
e8c9f186 | 403 | const struct btrfs_compress_op btrfs_zlib_compress = { |
261507a0 LZ |
404 | .alloc_workspace = zlib_alloc_workspace, |
405 | .free_workspace = zlib_free_workspace, | |
406 | .compress_pages = zlib_compress_pages, | |
974b1adc | 407 | .decompress_bio = zlib_decompress_bio, |
261507a0 LZ |
408 | .decompress = zlib_decompress, |
409 | }; |