module/os/linux/spl/spl-zlib.c

   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 <sys/kmem.h>
  57 #include <sys/kmem_cache.h>
  58 #include <sys/zmod.h>
  59
  60 static spl_kmem_cache_t *zlib_workspace_cache;
  61
  62 /*
  63  * A kmem_cache is used for the zlib workspaces to avoid having to vmalloc
  64  * and vfree for every call.  Using a kmem_cache also has the advantage
  65  * that improves the odds that the memory used will be local to this cpu.
  66  * To further improve things it might be wise to create a dedicated per-cpu
  67  * workspace for use.  This would take some additional care because we then
  68  * must disable preemption around the critical section, and verify that
  69  * zlib_deflate* and zlib_inflate* never internally call schedule().
  70  */
  71 static void *
  72 zlib_workspace_alloc(int flags)
  73 {
  74         return (kmem_cache_alloc(zlib_workspace_cache, flags & ~(__GFP_FS)));
  75 }
  76
  77 static void
  78 zlib_workspace_free(void *workspace)
  79 {
  80         kmem_cache_free(zlib_workspace_cache, workspace);
  81 }
  82
  83 /*
  84  * Compresses the source buffer into the destination buffer. The level
  85  * parameter has the same meaning as in deflateInit.  sourceLen is the byte
  86  * length of the source buffer. Upon entry, destLen is the total size of the
  87  * destination buffer, which must be at least 0.1% larger than sourceLen plus
  88  * 12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
  89  *
  90  * compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
  91  * memory, Z_BUF_ERROR if there was not enough room in the output buffer,
  92  * Z_STREAM_ERROR if the level parameter is invalid.
  93  */
  94 int
  95 z_compress_level(void *dest, size_t *destLen, const void *source,
  96     size_t sourceLen, int level)
  97 {
  98         z_stream stream;
  99         int err;
 100
 101         stream.next_in = (Byte *)source;
 102         stream.avail_in = (uInt)sourceLen;
 103         stream.next_out = dest;
 104         stream.avail_out = (uInt)*destLen;
 105
 106         if ((size_t)stream.avail_out != *destLen)
 107                 return (Z_BUF_ERROR);
 108
 109         stream.workspace = zlib_workspace_alloc(KM_SLEEP);
 110         if (!stream.workspace)
 111                 return (Z_MEM_ERROR);
 112
 113         err = zlib_deflateInit(&stream, level);
 114         if (err != Z_OK) {
 115                 zlib_workspace_free(stream.workspace);
 116                 return (err);
 117         }
 118
 119         err = zlib_deflate(&stream, Z_FINISH);
 120         if (err != Z_STREAM_END) {
 121                 zlib_deflateEnd(&stream);
 122                 zlib_workspace_free(stream.workspace);
 123                 return (err == Z_OK ? Z_BUF_ERROR : err);
 124         }
 125         *destLen = stream.total_out;
 126
 127         err = zlib_deflateEnd(&stream);
 128         zlib_workspace_free(stream.workspace);
 129
 130         return (err);
 131 }
 132 EXPORT_SYMBOL(z_compress_level);
 133
 134 /*
 135  * Decompresses the source buffer into the destination buffer.  sourceLen is
 136  * the byte length of the source buffer. Upon entry, destLen is the total
 137  * size of the destination buffer, which must be large enough to hold the
 138  * entire uncompressed data. (The size of the uncompressed data must have
 139  * been saved previously by the compressor and transmitted to the decompressor
 140  * by some mechanism outside the scope of this compression library.)
 141  * Upon exit, destLen is the actual size of the compressed buffer.
 142  * This function can be used to decompress a whole file at once if the
 143  * input file is mmap'ed.
 144  *
 145  * uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
 146  * enough memory, Z_BUF_ERROR if there was not enough room in the output
 147  * buffer, or Z_DATA_ERROR if the input data was corrupted.
 148  */
 149 int
 150 z_uncompress(void *dest, size_t *destLen, const void *source, size_t sourceLen)
 151 {
 152         z_stream stream;
 153         int err;
 154
 155         stream.next_in = (Byte *)source;
 156         stream.avail_in = (uInt)sourceLen;
 157         stream.next_out = dest;
 158         stream.avail_out = (uInt)*destLen;
 159
 160         if ((size_t)stream.avail_out != *destLen)
 161                 return (Z_BUF_ERROR);
 162
 163         stream.workspace = zlib_workspace_alloc(KM_SLEEP);
 164         if (!stream.workspace)
 165                 return (Z_MEM_ERROR);
 166
 167         err = zlib_inflateInit(&stream);
 168         if (err != Z_OK) {
 169                 zlib_workspace_free(stream.workspace);
 170                 return (err);
 171         }
 172
 173         err = zlib_inflate(&stream, Z_FINISH);
 174         if (err != Z_STREAM_END) {
 175                 zlib_inflateEnd(&stream);
 176                 zlib_workspace_free(stream.workspace);
 177
 178                 if (err == Z_NEED_DICT ||
 179                     (err == Z_BUF_ERROR && stream.avail_in == 0))
 180                         return (Z_DATA_ERROR);
 181
 182                 return (err);
 183         }
 184         *destLen = stream.total_out;
 185
 186         err = zlib_inflateEnd(&stream);
 187         zlib_workspace_free(stream.workspace);
 188
 189         return (err);
 190 }
 191 EXPORT_SYMBOL(z_uncompress);
 192
 193 int
 194 spl_zlib_init(void)
 195 {
 196         int size;
 197
 198         size = MAX(zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL),
 199             zlib_inflate_workspacesize());
 200
 201         zlib_workspace_cache = kmem_cache_create(
 202             "spl_zlib_workspace_cache",
 203             size, 0, NULL, NULL, NULL, NULL, NULL,
 204             KMC_KVMEM | KMC_RECLAIMABLE);
 205         if (!zlib_workspace_cache)
 206                 return (-ENOMEM);
 207
 208         return (0);
 209 }
 210
 211 void
 212 spl_zlib_fini(void)
 213 {
 214         kmem_cache_destroy(zlib_workspace_cache);
 215         zlib_workspace_cache = NULL;
 216 }