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Chris Masonc8b97812008-10-29 14:49:59 -04001/*
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>
Christoph Hellwigb2950862008-12-02 09:54:17 -050033#include "compression.h"
Chris Masonc8b97812008-10-29 14:49:59 -040034
Chris Masonc8b97812008-10-29 14:49:59 -040035struct workspace {
36 z_stream inf_strm;
37 z_stream def_strm;
38 char *buf;
39 struct list_head list;
40};
41
Li Zefan261507a02010-12-17 14:21:50 +080042static void zlib_free_workspace(struct list_head *ws)
Chris Masonc8b97812008-10-29 14:49:59 -040043{
Li Zefan261507a02010-12-17 14:21:50 +080044 struct workspace *workspace = list_entry(ws, struct workspace, list);
Chris Masonc8b97812008-10-29 14:49:59 -040045
Chris Masonc8b97812008-10-29 14:49:59 -040046 vfree(workspace->def_strm.workspace);
47 vfree(workspace->inf_strm.workspace);
48 kfree(workspace->buf);
49 kfree(workspace);
Chris Masonc8b97812008-10-29 14:49:59 -040050}
51
Li Zefan261507a02010-12-17 14:21:50 +080052static struct list_head *zlib_alloc_workspace(void)
Chris Masonc8b97812008-10-29 14:49:59 -040053{
54 struct workspace *workspace;
Li Zefan261507a02010-12-17 14:21:50 +080055
56 workspace = kzalloc(sizeof(*workspace), GFP_NOFS);
57 if (!workspace)
58 return ERR_PTR(-ENOMEM);
59
60 workspace->def_strm.workspace = vmalloc(zlib_deflate_workspacesize());
61 workspace->inf_strm.workspace = vmalloc(zlib_inflate_workspacesize());
62 workspace->buf = kmalloc(PAGE_CACHE_SIZE, GFP_NOFS);
63 if (!workspace->def_strm.workspace ||
64 !workspace->inf_strm.workspace || !workspace->buf)
65 goto fail;
66
67 INIT_LIST_HEAD(&workspace->list);
68
69 return &workspace->list;
70fail:
71 zlib_free_workspace(&workspace->list);
72 return ERR_PTR(-ENOMEM);
Chris Masonc8b97812008-10-29 14:49:59 -040073}
74
Li Zefan261507a02010-12-17 14:21:50 +080075static 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)
Chris Masonc8b97812008-10-29 14:49:59 -040084{
Li Zefan261507a02010-12-17 14:21:50 +080085 struct workspace *workspace = list_entry(ws, struct workspace, list);
Chris Masonc8b97812008-10-29 14:49:59 -040086 int ret;
Chris Masonc8b97812008-10-29 14:49:59 -040087 char *data_in;
88 char *cpage_out;
89 int nr_pages = 0;
90 struct page *in_page = NULL;
91 struct page *out_page = NULL;
Chris Masonc8b97812008-10-29 14:49:59 -040092 unsigned long bytes_left;
93
94 *out_pages = 0;
95 *total_out = 0;
96 *total_in = 0;
97
Chris Masonc8b97812008-10-29 14:49:59 -040098 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);
Li Zefan4b720292010-11-09 08:27:27 +0800111 if (out_page == NULL) {
112 ret = -1;
113 goto out;
114 }
Chris Masonc8b97812008-10-29 14:49:59 -0400115 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
Chris Masonc8b97812008-10-29 14:49:59 -0400124 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);
Li Zefan4b720292010-11-09 08:27:27 +0800153 if (out_page == NULL) {
154 ret = -1;
155 goto out;
156 }
Chris Masonc8b97812008-10-29 14:49:59 -0400157 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;
202out:
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 }
Chris Masonc8b97812008-10-29 14:49:59 -0400211 return ret;
212}
213
Li Zefan261507a02010-12-17 14:21:50 +0800214static 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)
Chris Masonc8b97812008-10-29 14:49:59 -0400219{
Li Zefan261507a02010-12-17 14:21:50 +0800220 struct workspace *workspace = list_entry(ws, struct workspace, list);
Li Zefan3a39c182010-11-08 15:22:19 +0800221 int ret = 0, ret2;
Chris Masonc8b97812008-10-29 14:49:59 -0400222 int wbits = MAX_WBITS;
Chris Masonc8b97812008-10-29 14:49:59 -0400223 char *data_in;
224 size_t total_out = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400225 unsigned long page_in_index = 0;
226 unsigned long page_out_index = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400227 unsigned long total_pages_in = (srclen + PAGE_CACHE_SIZE - 1) /
228 PAGE_CACHE_SIZE;
229 unsigned long buf_start;
Chris Masonc8b97812008-10-29 14:49:59 -0400230 unsigned long pg_offset;
Chris Masonc8b97812008-10-29 14:49:59 -0400231
Chris Masonc8b97812008-10-29 14:49:59 -0400232 data_in = kmap(pages_in[page_in_index]);
233 workspace->inf_strm.next_in = data_in;
Chris Mason5b050f02008-11-11 09:34:41 -0500234 workspace->inf_strm.avail_in = min_t(size_t, srclen, PAGE_CACHE_SIZE);
Chris Masonc8b97812008-10-29 14:49:59 -0400235 workspace->inf_strm.total_in = 0;
236
237 workspace->inf_strm.total_out = 0;
238 workspace->inf_strm.next_out = workspace->buf;
239 workspace->inf_strm.avail_out = PAGE_CACHE_SIZE;
Chris Masonc8b97812008-10-29 14:49:59 -0400240 pg_offset = 0;
241
242 /* If it's deflate, and it's got no preset dictionary, then
243 we can tell zlib to skip the adler32 check. */
244 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
245 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
246 !(((data_in[0]<<8) + data_in[1]) % 31)) {
247
248 wbits = -((data_in[0] >> 4) + 8);
249 workspace->inf_strm.next_in += 2;
250 workspace->inf_strm.avail_in -= 2;
251 }
252
253 if (Z_OK != zlib_inflateInit2(&workspace->inf_strm, wbits)) {
254 printk(KERN_WARNING "inflateInit failed\n");
Li Zefan261507a02010-12-17 14:21:50 +0800255 return -1;
Chris Masonc8b97812008-10-29 14:49:59 -0400256 }
Chris Masond3977122009-01-05 21:25:51 -0500257 while (workspace->inf_strm.total_in < srclen) {
Chris Masonc8b97812008-10-29 14:49:59 -0400258 ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH);
Chris Masond3977122009-01-05 21:25:51 -0500259 if (ret != Z_OK && ret != Z_STREAM_END)
Chris Masonc8b97812008-10-29 14:49:59 -0400260 break;
Chris Masonc8b97812008-10-29 14:49:59 -0400261
Li Zefan3a39c182010-11-08 15:22:19 +0800262 buf_start = total_out;
Chris Masonc8b97812008-10-29 14:49:59 -0400263 total_out = workspace->inf_strm.total_out;
264
Li Zefan3a39c182010-11-08 15:22:19 +0800265 /* we didn't make progress in this inflate call, we're done */
266 if (buf_start == total_out)
Chris Masonc8b97812008-10-29 14:49:59 -0400267 break;
Li Zefan3a39c182010-11-08 15:22:19 +0800268
269 ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start,
270 total_out, disk_start,
271 bvec, vcnt,
272 &page_out_index, &pg_offset);
273 if (ret2 == 0) {
274 ret = 0;
275 goto done;
Chris Masonc8b97812008-10-29 14:49:59 -0400276 }
277
Chris Masonc8b97812008-10-29 14:49:59 -0400278 workspace->inf_strm.next_out = workspace->buf;
279 workspace->inf_strm.avail_out = PAGE_CACHE_SIZE;
280
281 if (workspace->inf_strm.avail_in == 0) {
282 unsigned long tmp;
283 kunmap(pages_in[page_in_index]);
284 page_in_index++;
285 if (page_in_index >= total_pages_in) {
286 data_in = NULL;
287 break;
288 }
289 data_in = kmap(pages_in[page_in_index]);
290 workspace->inf_strm.next_in = data_in;
291 tmp = srclen - workspace->inf_strm.total_in;
292 workspace->inf_strm.avail_in = min(tmp,
293 PAGE_CACHE_SIZE);
294 }
295 }
Chris Masond3977122009-01-05 21:25:51 -0500296 if (ret != Z_STREAM_END)
Chris Masonc8b97812008-10-29 14:49:59 -0400297 ret = -1;
Chris Masond3977122009-01-05 21:25:51 -0500298 else
Chris Masonc8b97812008-10-29 14:49:59 -0400299 ret = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400300done:
301 zlib_inflateEnd(&workspace->inf_strm);
302 if (data_in)
303 kunmap(pages_in[page_in_index]);
Chris Masonc8b97812008-10-29 14:49:59 -0400304 return ret;
305}
306
Li Zefan261507a02010-12-17 14:21:50 +0800307static int zlib_decompress(struct list_head *ws, unsigned char *data_in,
308 struct page *dest_page,
309 unsigned long start_byte,
310 size_t srclen, size_t destlen)
Chris Masonc8b97812008-10-29 14:49:59 -0400311{
Li Zefan261507a02010-12-17 14:21:50 +0800312 struct workspace *workspace = list_entry(ws, struct workspace, list);
Chris Masonc8b97812008-10-29 14:49:59 -0400313 int ret = 0;
314 int wbits = MAX_WBITS;
Chris Masonc8b97812008-10-29 14:49:59 -0400315 unsigned long bytes_left = destlen;
316 unsigned long total_out = 0;
317 char *kaddr;
318
Chris Masonc8b97812008-10-29 14:49:59 -0400319 workspace->inf_strm.next_in = data_in;
320 workspace->inf_strm.avail_in = srclen;
321 workspace->inf_strm.total_in = 0;
322
323 workspace->inf_strm.next_out = workspace->buf;
324 workspace->inf_strm.avail_out = PAGE_CACHE_SIZE;
325 workspace->inf_strm.total_out = 0;
326 /* If it's deflate, and it's got no preset dictionary, then
327 we can tell zlib to skip the adler32 check. */
328 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
329 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
330 !(((data_in[0]<<8) + data_in[1]) % 31)) {
331
332 wbits = -((data_in[0] >> 4) + 8);
333 workspace->inf_strm.next_in += 2;
334 workspace->inf_strm.avail_in -= 2;
335 }
336
337 if (Z_OK != zlib_inflateInit2(&workspace->inf_strm, wbits)) {
338 printk(KERN_WARNING "inflateInit failed\n");
Li Zefan261507a02010-12-17 14:21:50 +0800339 return -1;
Chris Masonc8b97812008-10-29 14:49:59 -0400340 }
341
Chris Masond3977122009-01-05 21:25:51 -0500342 while (bytes_left > 0) {
Chris Masonc8b97812008-10-29 14:49:59 -0400343 unsigned long buf_start;
344 unsigned long buf_offset;
345 unsigned long bytes;
346 unsigned long pg_offset = 0;
347
348 ret = zlib_inflate(&workspace->inf_strm, Z_NO_FLUSH);
Chris Masond3977122009-01-05 21:25:51 -0500349 if (ret != Z_OK && ret != Z_STREAM_END)
Chris Masonc8b97812008-10-29 14:49:59 -0400350 break;
Chris Masonc8b97812008-10-29 14:49:59 -0400351
352 buf_start = total_out;
353 total_out = workspace->inf_strm.total_out;
354
355 if (total_out == buf_start) {
356 ret = -1;
357 break;
358 }
359
Chris Masond3977122009-01-05 21:25:51 -0500360 if (total_out <= start_byte)
Chris Masonc8b97812008-10-29 14:49:59 -0400361 goto next;
Chris Masonc8b97812008-10-29 14:49:59 -0400362
Chris Masond3977122009-01-05 21:25:51 -0500363 if (total_out > start_byte && buf_start < start_byte)
Chris Masonc8b97812008-10-29 14:49:59 -0400364 buf_offset = start_byte - buf_start;
Chris Masond3977122009-01-05 21:25:51 -0500365 else
Chris Masonc8b97812008-10-29 14:49:59 -0400366 buf_offset = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400367
368 bytes = min(PAGE_CACHE_SIZE - pg_offset,
369 PAGE_CACHE_SIZE - buf_offset);
370 bytes = min(bytes, bytes_left);
371
372 kaddr = kmap_atomic(dest_page, KM_USER0);
373 memcpy(kaddr + pg_offset, workspace->buf + buf_offset, bytes);
374 kunmap_atomic(kaddr, KM_USER0);
375
376 pg_offset += bytes;
377 bytes_left -= bytes;
378next:
379 workspace->inf_strm.next_out = workspace->buf;
380 workspace->inf_strm.avail_out = PAGE_CACHE_SIZE;
381 }
Chris Masond3977122009-01-05 21:25:51 -0500382
383 if (ret != Z_STREAM_END && bytes_left != 0)
Chris Masonc8b97812008-10-29 14:49:59 -0400384 ret = -1;
Chris Masond3977122009-01-05 21:25:51 -0500385 else
Chris Masonc8b97812008-10-29 14:49:59 -0400386 ret = 0;
Chris Masond3977122009-01-05 21:25:51 -0500387
Chris Masonc8b97812008-10-29 14:49:59 -0400388 zlib_inflateEnd(&workspace->inf_strm);
Chris Masonc8b97812008-10-29 14:49:59 -0400389 return ret;
390}
391
Li Zefan261507a02010-12-17 14:21:50 +0800392struct btrfs_compress_op btrfs_zlib_compress = {
393 .alloc_workspace = zlib_alloc_workspace,
394 .free_workspace = zlib_free_workspace,
395 .compress_pages = zlib_compress_pages,
396 .decompress_biovec = zlib_decompress_biovec,
397 .decompress = zlib_decompress,
398};