blob: fb22fd8d8fb8fad73cb4d2b63d4d525da3eea876 [file] [log] [blame]
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 {
Sergey Senozhatsky78809912014-07-07 23:38:29 +090036 z_stream strm;
Chris Masonc8b97812008-10-29 14:49:59 -040037 char *buf;
38 struct list_head list;
39};
40
Li Zefan261507a02010-12-17 14:21:50 +080041static void zlib_free_workspace(struct list_head *ws)
Chris Masonc8b97812008-10-29 14:49:59 -040042{
Li Zefan261507a02010-12-17 14:21:50 +080043 struct workspace *workspace = list_entry(ws, struct workspace, list);
Chris Masonc8b97812008-10-29 14:49:59 -040044
Sergey Senozhatsky78809912014-07-07 23:38:29 +090045 vfree(workspace->strm.workspace);
Chris Masonc8b97812008-10-29 14:49:59 -040046 kfree(workspace->buf);
47 kfree(workspace);
Chris Masonc8b97812008-10-29 14:49:59 -040048}
49
Li Zefan261507a02010-12-17 14:21:50 +080050static struct list_head *zlib_alloc_workspace(void)
Chris Masonc8b97812008-10-29 14:49:59 -040051{
52 struct workspace *workspace;
Sergey Senozhatsky78809912014-07-07 23:38:29 +090053 int workspacesize;
Li Zefan261507a02010-12-17 14:21:50 +080054
55 workspace = kzalloc(sizeof(*workspace), GFP_NOFS);
56 if (!workspace)
57 return ERR_PTR(-ENOMEM);
58
Sergey Senozhatsky78809912014-07-07 23:38:29 +090059 workspacesize = max(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
60 zlib_inflate_workspacesize());
61 workspace->strm.workspace = vmalloc(workspacesize);
Li Zefan261507a02010-12-17 14:21:50 +080062 workspace->buf = kmalloc(PAGE_CACHE_SIZE, GFP_NOFS);
Sergey Senozhatsky78809912014-07-07 23:38:29 +090063 if (!workspace->strm.workspace || !workspace->buf)
Li Zefan261507a02010-12-17 14:21:50 +080064 goto fail;
65
66 INIT_LIST_HEAD(&workspace->list);
67
68 return &workspace->list;
69fail:
70 zlib_free_workspace(&workspace->list);
71 return ERR_PTR(-ENOMEM);
Chris Masonc8b97812008-10-29 14:49:59 -040072}
73
Li Zefan261507a02010-12-17 14:21:50 +080074static int zlib_compress_pages(struct list_head *ws,
75 struct address_space *mapping,
76 u64 start, unsigned long len,
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)
Chris Masonc8b97812008-10-29 14:49:59 -040083{
Li Zefan261507a02010-12-17 14:21:50 +080084 struct workspace *workspace = list_entry(ws, struct workspace, list);
Chris Masonc8b97812008-10-29 14:49:59 -040085 int ret;
Chris Masonc8b97812008-10-29 14:49:59 -040086 char *data_in;
87 char *cpage_out;
88 int nr_pages = 0;
89 struct page *in_page = NULL;
90 struct page *out_page = NULL;
Chris Masonc8b97812008-10-29 14:49:59 -040091 unsigned long bytes_left;
92
93 *out_pages = 0;
94 *total_out = 0;
95 *total_in = 0;
96
Sergey Senozhatsky78809912014-07-07 23:38:29 +090097 if (Z_OK != zlib_deflateInit(&workspace->strm, 3)) {
Frank Holtonefe120a2013-12-20 11:37:06 -050098 printk(KERN_WARNING "BTRFS: deflateInit failed\n");
Zach Brown60e19752014-05-09 17:15:08 -040099 ret = -EIO;
Chris Masonc8b97812008-10-29 14:49:59 -0400100 goto out;
101 }
102
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900103 workspace->strm.total_in = 0;
104 workspace->strm.total_out = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400105
106 in_page = find_get_page(mapping, start >> PAGE_CACHE_SHIFT);
107 data_in = kmap(in_page);
108
109 out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
Li Zefan4b720292010-11-09 08:27:27 +0800110 if (out_page == NULL) {
Zach Brown60e19752014-05-09 17:15:08 -0400111 ret = -ENOMEM;
Li Zefan4b720292010-11-09 08:27:27 +0800112 goto out;
113 }
Chris Masonc8b97812008-10-29 14:49:59 -0400114 cpage_out = kmap(out_page);
115 pages[0] = out_page;
116 nr_pages = 1;
117
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900118 workspace->strm.next_in = data_in;
119 workspace->strm.next_out = cpage_out;
120 workspace->strm.avail_out = PAGE_CACHE_SIZE;
121 workspace->strm.avail_in = min(len, PAGE_CACHE_SIZE);
Chris Masonc8b97812008-10-29 14:49:59 -0400122
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900123 while (workspace->strm.total_in < len) {
124 ret = zlib_deflate(&workspace->strm, Z_SYNC_FLUSH);
Chris Masonc8b97812008-10-29 14:49:59 -0400125 if (ret != Z_OK) {
Frank Holtonefe120a2013-12-20 11:37:06 -0500126 printk(KERN_DEBUG "BTRFS: deflate in loop returned %d\n",
Chris Masonc8b97812008-10-29 14:49:59 -0400127 ret);
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900128 zlib_deflateEnd(&workspace->strm);
Zach Brown60e19752014-05-09 17:15:08 -0400129 ret = -EIO;
Chris Masonc8b97812008-10-29 14:49:59 -0400130 goto out;
131 }
132
133 /* we're making it bigger, give up */
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900134 if (workspace->strm.total_in > 8192 &&
135 workspace->strm.total_in <
136 workspace->strm.total_out) {
David Sterba130d5b42014-06-20 11:43:20 +0200137 ret = -E2BIG;
Chris Masonc8b97812008-10-29 14:49:59 -0400138 goto out;
139 }
140 /* we need another page for writing out. Test this
141 * before the total_in so we will pull in a new page for
142 * the stream end if required
143 */
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900144 if (workspace->strm.avail_out == 0) {
Chris Masonc8b97812008-10-29 14:49:59 -0400145 kunmap(out_page);
146 if (nr_pages == nr_dest_pages) {
147 out_page = NULL;
Zach Brown60e19752014-05-09 17:15:08 -0400148 ret = -E2BIG;
Chris Masonc8b97812008-10-29 14:49:59 -0400149 goto out;
150 }
151 out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
Li Zefan4b720292010-11-09 08:27:27 +0800152 if (out_page == NULL) {
Zach Brown60e19752014-05-09 17:15:08 -0400153 ret = -ENOMEM;
Li Zefan4b720292010-11-09 08:27:27 +0800154 goto out;
155 }
Chris Masonc8b97812008-10-29 14:49:59 -0400156 cpage_out = kmap(out_page);
157 pages[nr_pages] = out_page;
158 nr_pages++;
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900159 workspace->strm.avail_out = PAGE_CACHE_SIZE;
160 workspace->strm.next_out = cpage_out;
Chris Masonc8b97812008-10-29 14:49:59 -0400161 }
162 /* we're all done */
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900163 if (workspace->strm.total_in >= len)
Chris Masonc8b97812008-10-29 14:49:59 -0400164 break;
165
166 /* we've read in a full page, get a new one */
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900167 if (workspace->strm.avail_in == 0) {
168 if (workspace->strm.total_out > max_out)
Chris Masonc8b97812008-10-29 14:49:59 -0400169 break;
170
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900171 bytes_left = len - workspace->strm.total_in;
Chris Masonc8b97812008-10-29 14:49:59 -0400172 kunmap(in_page);
173 page_cache_release(in_page);
174
175 start += PAGE_CACHE_SIZE;
176 in_page = find_get_page(mapping,
177 start >> PAGE_CACHE_SHIFT);
178 data_in = kmap(in_page);
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900179 workspace->strm.avail_in = min(bytes_left,
Chris Masonc8b97812008-10-29 14:49:59 -0400180 PAGE_CACHE_SIZE);
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900181 workspace->strm.next_in = data_in;
Chris Masonc8b97812008-10-29 14:49:59 -0400182 }
183 }
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900184 workspace->strm.avail_in = 0;
185 ret = zlib_deflate(&workspace->strm, Z_FINISH);
186 zlib_deflateEnd(&workspace->strm);
Chris Masonc8b97812008-10-29 14:49:59 -0400187
188 if (ret != Z_STREAM_END) {
Zach Brown60e19752014-05-09 17:15:08 -0400189 ret = -EIO;
Chris Masonc8b97812008-10-29 14:49:59 -0400190 goto out;
191 }
192
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900193 if (workspace->strm.total_out >= workspace->strm.total_in) {
Zach Brown60e19752014-05-09 17:15:08 -0400194 ret = -E2BIG;
Chris Masonc8b97812008-10-29 14:49:59 -0400195 goto out;
196 }
197
198 ret = 0;
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900199 *total_out = workspace->strm.total_out;
200 *total_in = workspace->strm.total_in;
Chris Masonc8b97812008-10-29 14:49:59 -0400201out:
202 *out_pages = nr_pages;
203 if (out_page)
204 kunmap(out_page);
205
206 if (in_page) {
207 kunmap(in_page);
208 page_cache_release(in_page);
209 }
Chris Masonc8b97812008-10-29 14:49:59 -0400210 return ret;
211}
212
Li Zefan261507a02010-12-17 14:21:50 +0800213static int zlib_decompress_biovec(struct list_head *ws, struct page **pages_in,
214 u64 disk_start,
215 struct bio_vec *bvec,
216 int vcnt,
217 size_t srclen)
Chris Masonc8b97812008-10-29 14:49:59 -0400218{
Li Zefan261507a02010-12-17 14:21:50 +0800219 struct workspace *workspace = list_entry(ws, struct workspace, list);
Li Zefan3a39c182010-11-08 15:22:19 +0800220 int ret = 0, ret2;
Chris Masonc8b97812008-10-29 14:49:59 -0400221 int wbits = MAX_WBITS;
Chris Masonc8b97812008-10-29 14:49:59 -0400222 char *data_in;
223 size_t total_out = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400224 unsigned long page_in_index = 0;
225 unsigned long page_out_index = 0;
David Sterbaed6078f2014-06-05 01:59:57 +0200226 unsigned long total_pages_in = DIV_ROUND_UP(srclen, PAGE_CACHE_SIZE);
Chris Masonc8b97812008-10-29 14:49:59 -0400227 unsigned long buf_start;
Chris Masonc8b97812008-10-29 14:49:59 -0400228 unsigned long pg_offset;
Chris Masonc8b97812008-10-29 14:49:59 -0400229
Chris Masonc8b97812008-10-29 14:49:59 -0400230 data_in = kmap(pages_in[page_in_index]);
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900231 workspace->strm.next_in = data_in;
232 workspace->strm.avail_in = min_t(size_t, srclen, PAGE_CACHE_SIZE);
233 workspace->strm.total_in = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400234
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900235 workspace->strm.total_out = 0;
236 workspace->strm.next_out = workspace->buf;
237 workspace->strm.avail_out = PAGE_CACHE_SIZE;
Chris Masonc8b97812008-10-29 14:49:59 -0400238 pg_offset = 0;
239
240 /* If it's deflate, and it's got no preset dictionary, then
241 we can tell zlib to skip the adler32 check. */
242 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
243 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
244 !(((data_in[0]<<8) + data_in[1]) % 31)) {
245
246 wbits = -((data_in[0] >> 4) + 8);
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900247 workspace->strm.next_in += 2;
248 workspace->strm.avail_in -= 2;
Chris Masonc8b97812008-10-29 14:49:59 -0400249 }
250
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900251 if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) {
Frank Holtonefe120a2013-12-20 11:37:06 -0500252 printk(KERN_WARNING "BTRFS: inflateInit failed\n");
Zach Brown60e19752014-05-09 17:15:08 -0400253 return -EIO;
Chris Masonc8b97812008-10-29 14:49:59 -0400254 }
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900255 while (workspace->strm.total_in < srclen) {
256 ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
Chris Masond3977122009-01-05 21:25:51 -0500257 if (ret != Z_OK && ret != Z_STREAM_END)
Chris Masonc8b97812008-10-29 14:49:59 -0400258 break;
Chris Masonc8b97812008-10-29 14:49:59 -0400259
Li Zefan3a39c182010-11-08 15:22:19 +0800260 buf_start = total_out;
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900261 total_out = workspace->strm.total_out;
Chris Masonc8b97812008-10-29 14:49:59 -0400262
Li Zefan3a39c182010-11-08 15:22:19 +0800263 /* we didn't make progress in this inflate call, we're done */
264 if (buf_start == total_out)
Chris Masonc8b97812008-10-29 14:49:59 -0400265 break;
Li Zefan3a39c182010-11-08 15:22:19 +0800266
267 ret2 = btrfs_decompress_buf2page(workspace->buf, buf_start,
268 total_out, disk_start,
269 bvec, vcnt,
270 &page_out_index, &pg_offset);
271 if (ret2 == 0) {
272 ret = 0;
273 goto done;
Chris Masonc8b97812008-10-29 14:49:59 -0400274 }
275
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900276 workspace->strm.next_out = workspace->buf;
277 workspace->strm.avail_out = PAGE_CACHE_SIZE;
Chris Masonc8b97812008-10-29 14:49:59 -0400278
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900279 if (workspace->strm.avail_in == 0) {
Chris Masonc8b97812008-10-29 14:49:59 -0400280 unsigned long tmp;
281 kunmap(pages_in[page_in_index]);
282 page_in_index++;
283 if (page_in_index >= total_pages_in) {
284 data_in = NULL;
285 break;
286 }
287 data_in = kmap(pages_in[page_in_index]);
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900288 workspace->strm.next_in = data_in;
289 tmp = srclen - workspace->strm.total_in;
290 workspace->strm.avail_in = min(tmp,
Chris Masonc8b97812008-10-29 14:49:59 -0400291 PAGE_CACHE_SIZE);
292 }
293 }
Chris Masond3977122009-01-05 21:25:51 -0500294 if (ret != Z_STREAM_END)
Zach Brown60e19752014-05-09 17:15:08 -0400295 ret = -EIO;
Chris Masond3977122009-01-05 21:25:51 -0500296 else
Chris Masonc8b97812008-10-29 14:49:59 -0400297 ret = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400298done:
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900299 zlib_inflateEnd(&workspace->strm);
Chris Masonc8b97812008-10-29 14:49:59 -0400300 if (data_in)
301 kunmap(pages_in[page_in_index]);
Chris Mason2f19cad2014-11-30 08:56:33 -0500302 if (!ret)
303 btrfs_clear_biovec_end(bvec, vcnt, page_out_index, pg_offset);
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 Mason2f19cad2014-11-30 08:56:33 -0500315 unsigned long bytes_left;
Chris Masonc8b97812008-10-29 14:49:59 -0400316 unsigned long total_out = 0;
Chris Mason2f19cad2014-11-30 08:56:33 -0500317 unsigned long pg_offset = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400318 char *kaddr;
319
Chris Mason2f19cad2014-11-30 08:56:33 -0500320 destlen = min_t(unsigned long, destlen, PAGE_SIZE);
321 bytes_left = destlen;
322
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900323 workspace->strm.next_in = data_in;
324 workspace->strm.avail_in = srclen;
325 workspace->strm.total_in = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400326
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900327 workspace->strm.next_out = workspace->buf;
328 workspace->strm.avail_out = PAGE_CACHE_SIZE;
329 workspace->strm.total_out = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400330 /* If it's deflate, and it's got no preset dictionary, then
331 we can tell zlib to skip the adler32 check. */
332 if (srclen > 2 && !(data_in[1] & PRESET_DICT) &&
333 ((data_in[0] & 0x0f) == Z_DEFLATED) &&
334 !(((data_in[0]<<8) + data_in[1]) % 31)) {
335
336 wbits = -((data_in[0] >> 4) + 8);
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900337 workspace->strm.next_in += 2;
338 workspace->strm.avail_in -= 2;
Chris Masonc8b97812008-10-29 14:49:59 -0400339 }
340
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900341 if (Z_OK != zlib_inflateInit2(&workspace->strm, wbits)) {
Frank Holtonefe120a2013-12-20 11:37:06 -0500342 printk(KERN_WARNING "BTRFS: inflateInit failed\n");
Zach Brown60e19752014-05-09 17:15:08 -0400343 return -EIO;
Chris Masonc8b97812008-10-29 14:49:59 -0400344 }
345
Chris Masond3977122009-01-05 21:25:51 -0500346 while (bytes_left > 0) {
Chris Masonc8b97812008-10-29 14:49:59 -0400347 unsigned long buf_start;
348 unsigned long buf_offset;
349 unsigned long bytes;
Chris Masonc8b97812008-10-29 14:49:59 -0400350
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900351 ret = zlib_inflate(&workspace->strm, Z_NO_FLUSH);
Chris Masond3977122009-01-05 21:25:51 -0500352 if (ret != Z_OK && ret != Z_STREAM_END)
Chris Masonc8b97812008-10-29 14:49:59 -0400353 break;
Chris Masonc8b97812008-10-29 14:49:59 -0400354
355 buf_start = total_out;
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900356 total_out = workspace->strm.total_out;
Chris Masonc8b97812008-10-29 14:49:59 -0400357
358 if (total_out == buf_start) {
Zach Brown60e19752014-05-09 17:15:08 -0400359 ret = -EIO;
Chris Masonc8b97812008-10-29 14:49:59 -0400360 break;
361 }
362
Chris Masond3977122009-01-05 21:25:51 -0500363 if (total_out <= start_byte)
Chris Masonc8b97812008-10-29 14:49:59 -0400364 goto next;
Chris Masonc8b97812008-10-29 14:49:59 -0400365
Chris Masond3977122009-01-05 21:25:51 -0500366 if (total_out > start_byte && buf_start < start_byte)
Chris Masonc8b97812008-10-29 14:49:59 -0400367 buf_offset = start_byte - buf_start;
Chris Masond3977122009-01-05 21:25:51 -0500368 else
Chris Masonc8b97812008-10-29 14:49:59 -0400369 buf_offset = 0;
Chris Masonc8b97812008-10-29 14:49:59 -0400370
371 bytes = min(PAGE_CACHE_SIZE - pg_offset,
372 PAGE_CACHE_SIZE - buf_offset);
373 bytes = min(bytes, bytes_left);
374
Cong Wang7ac687d2011-11-25 23:14:28 +0800375 kaddr = kmap_atomic(dest_page);
Chris Masonc8b97812008-10-29 14:49:59 -0400376 memcpy(kaddr + pg_offset, workspace->buf + buf_offset, bytes);
Cong Wang7ac687d2011-11-25 23:14:28 +0800377 kunmap_atomic(kaddr);
Chris Masonc8b97812008-10-29 14:49:59 -0400378
379 pg_offset += bytes;
380 bytes_left -= bytes;
381next:
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900382 workspace->strm.next_out = workspace->buf;
383 workspace->strm.avail_out = PAGE_CACHE_SIZE;
Chris Masonc8b97812008-10-29 14:49:59 -0400384 }
Chris Masond3977122009-01-05 21:25:51 -0500385
386 if (ret != Z_STREAM_END && bytes_left != 0)
Zach Brown60e19752014-05-09 17:15:08 -0400387 ret = -EIO;
Chris Masond3977122009-01-05 21:25:51 -0500388 else
Chris Masonc8b97812008-10-29 14:49:59 -0400389 ret = 0;
Chris Masond3977122009-01-05 21:25:51 -0500390
Sergey Senozhatsky78809912014-07-07 23:38:29 +0900391 zlib_inflateEnd(&workspace->strm);
Chris Mason2f19cad2014-11-30 08:56:33 -0500392
393 /*
394 * this should only happen if zlib returned fewer bytes than we
395 * expected. btrfs_get_block is responsible for zeroing from the
396 * end of the inline extent (destlen) to the end of the page
397 */
398 if (pg_offset < destlen) {
399 kaddr = kmap_atomic(dest_page);
400 memset(kaddr + pg_offset, 0, destlen - pg_offset);
401 kunmap_atomic(kaddr);
402 }
Chris Masonc8b97812008-10-29 14:49:59 -0400403 return ret;
404}
405
Li Zefan261507a02010-12-17 14:21:50 +0800406struct btrfs_compress_op btrfs_zlib_compress = {
407 .alloc_workspace = zlib_alloc_workspace,
408 .free_workspace = zlib_free_workspace,
409 .compress_pages = zlib_compress_pages,
410 .decompress_biovec = zlib_decompress_biovec,
411 .decompress = zlib_decompress,
412};