1 /*
2 * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
3 * Copyright (C) 2007 The Regents of the University of California.
4 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
5 * Written by Brian Behlendorf <behlendorf1@llnl.gov>.
6 * UCRL-CODE-235197
7 *
8 * This file is part of the SPL, Solaris Porting Layer.
9 *
10 * The SPL is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
14 *
15 * The SPL is distributed in the hope that it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 * for more details.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with the SPL. If not, see <http://www.gnu.org/licenses/>.
22 *
23 *
24 * z_compress_level/z_uncompress are nearly identical copies of the
25 * compress2/uncompress functions provided by the official zlib package
26 * available at http://zlib.net/. The only changes made we to slightly
27 * adapt the functions called to match the linux kernel implementation
28 * of zlib. The full zlib license follows:
29 *
30 * zlib.h -- interface of the 'zlib' general purpose compression library
31 * version 1.2.5, April 19th, 2010
32 *
33 * Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler
34 *
35 * This software is provided 'as-is', without any express or implied
36 * warranty. In no event will the authors be held liable for any damages
37 * arising from the use of this software.
38 *
39 * Permission is granted to anyone to use this software for any purpose,
40 * including commercial applications, and to alter it and redistribute it
41 * freely, subject to the following restrictions:
42 *
43 * 1. The origin of this software must not be misrepresented; you must not
44 * claim that you wrote the original software. If you use this software
45 * in a product, an acknowledgment in the product documentation would be
46 * appreciated but is not required.
47 * 2. Altered source versions must be plainly marked as such, and must not be
48 * misrepresented as being the original software.
49 * 3. This notice may not be removed or altered from any source distribution.
50 *
51 * Jean-loup Gailly
52 * Mark Adler
53 */
54
55
56 #include <linux/percpu_compat.h>
57 #include <sys/kmem.h>
58 #include <sys/kmem_cache.h>
59 #include <sys/zmod.h>
60
61 static spl_kmem_cache_t *zlib_workspace_cache;
62
63 /*
64 * A kmem_cache is used for the zlib workspaces to avoid having to vmalloc
65 * and vfree for every call. Using a kmem_cache also has the advantage
66 * that improves the odds that the memory used will be local to this cpu.
67 * To further improve things it might be wise to create a dedicated per-cpu
68 * workspace for use. This would take some additional care because we then
69 * must disable preemption around the critical section, and verify that
70 * zlib_deflate* and zlib_inflate* never internally call schedule().
71 */
72 static void *
zlib_workspace_alloc(int flags)73 zlib_workspace_alloc(int flags)
74 {
75 return (kmem_cache_alloc(zlib_workspace_cache, flags & ~(__GFP_FS)));
76 }
77
78 static void
zlib_workspace_free(void * workspace)79 zlib_workspace_free(void *workspace)
80 {
81 kmem_cache_free(zlib_workspace_cache, workspace);
82 }
83
84 /*
85 * Compresses the source buffer into the destination buffer. The level
86 * parameter has the same meaning as in deflateInit. sourceLen is the byte
87 * length of the source buffer. Upon entry, destLen is the total size of the
88 * destination buffer, which must be at least 0.1% larger than sourceLen plus
89 * 12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
90 *
91 * compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
92 * memory, Z_BUF_ERROR if there was not enough room in the output buffer,
93 * Z_STREAM_ERROR if the level parameter is invalid.
94 */
95 int
z_compress_level(void * dest,size_t * destLen,const void * source,size_t sourceLen,int level)96 z_compress_level(void *dest, size_t *destLen, const void *source,
97 size_t sourceLen, int level)
98 {
99 z_stream stream;
100 int err;
101
102 stream.next_in = (Byte *)source;
103 stream.avail_in = (uInt)sourceLen;
104 stream.next_out = dest;
105 stream.avail_out = (uInt)*destLen;
106
107 if ((size_t)stream.avail_out != *destLen)
108 return (Z_BUF_ERROR);
109
110 stream.workspace = zlib_workspace_alloc(KM_SLEEP);
111 if (!stream.workspace)
112 return (Z_MEM_ERROR);
113
114 err = zlib_deflateInit(&stream, level);
115 if (err != Z_OK) {
116 zlib_workspace_free(stream.workspace);
117 return (err);
118 }
119
120 err = zlib_deflate(&stream, Z_FINISH);
121 if (err != Z_STREAM_END) {
122 zlib_deflateEnd(&stream);
123 zlib_workspace_free(stream.workspace);
124 return (err == Z_OK ? Z_BUF_ERROR : err);
125 }
126 *destLen = stream.total_out;
127
128 err = zlib_deflateEnd(&stream);
129 zlib_workspace_free(stream.workspace);
130
131 return (err);
132 }
133 EXPORT_SYMBOL(z_compress_level);
134
135 /*
136 * Decompresses the source buffer into the destination buffer. sourceLen is
137 * the byte length of the source buffer. Upon entry, destLen is the total
138 * size of the destination buffer, which must be large enough to hold the
139 * entire uncompressed data. (The size of the uncompressed data must have
140 * been saved previously by the compressor and transmitted to the decompressor
141 * by some mechanism outside the scope of this compression library.)
142 * Upon exit, destLen is the actual size of the compressed buffer.
143 * This function can be used to decompress a whole file at once if the
144 * input file is mmap'ed.
145 *
146 * uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
147 * enough memory, Z_BUF_ERROR if there was not enough room in the output
148 * buffer, or Z_DATA_ERROR if the input data was corrupted.
149 */
150 int
z_uncompress(void * dest,size_t * destLen,const void * source,size_t sourceLen)151 z_uncompress(void *dest, size_t *destLen, const void *source, size_t sourceLen)
152 {
153 z_stream stream;
154 int err;
155
156 stream.next_in = (Byte *)source;
157 stream.avail_in = (uInt)sourceLen;
158 stream.next_out = dest;
159 stream.avail_out = (uInt)*destLen;
160
161 if ((size_t)stream.avail_out != *destLen)
162 return (Z_BUF_ERROR);
163
164 stream.workspace = zlib_workspace_alloc(KM_SLEEP);
165 if (!stream.workspace)
166 return (Z_MEM_ERROR);
167
168 err = zlib_inflateInit(&stream);
169 if (err != Z_OK) {
170 zlib_workspace_free(stream.workspace);
171 return (err);
172 }
173
174 err = zlib_inflate(&stream, Z_FINISH);
175 if (err != Z_STREAM_END) {
176 zlib_inflateEnd(&stream);
177 zlib_workspace_free(stream.workspace);
178
179 if (err == Z_NEED_DICT ||
180 (err == Z_BUF_ERROR && stream.avail_in == 0))
181 return (Z_DATA_ERROR);
182
183 return (err);
184 }
185 *destLen = stream.total_out;
186
187 err = zlib_inflateEnd(&stream);
188 zlib_workspace_free(stream.workspace);
189
190 return (err);
191 }
192 EXPORT_SYMBOL(z_uncompress);
193
194 int
spl_zlib_init(void)195 spl_zlib_init(void)
196 {
197 int size;
198
199 size = MAX(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
200 zlib_inflate_workspacesize());
201
202 zlib_workspace_cache = kmem_cache_create(
203 "spl_zlib_workspace_cache",
204 size, 0, NULL, NULL, NULL, NULL, NULL,
205 KMC_KVMEM);
206 if (!zlib_workspace_cache)
207 return (-ENOMEM);
208
209 return (0);
210 }
211
212 void
spl_zlib_fini(void)213 spl_zlib_fini(void)
214 {
215 kmem_cache_destroy(zlib_workspace_cache);
216 zlib_workspace_cache = NULL;
217 }
218